Injection molding machine

Abstract

The utility model discloses an injection molding machine which comprises a main glue injection nozzle, a machine table, a plurality of glue injection modules and a mold assembly, the main glue injection nozzle is connected with the machine table, and a main runner communicated with the main glue injection nozzle is arranged in the machine table; the glue injection module is connected with the machine table and comprises glue storage bins, a hydraulic cylinder and a branch runner, the main runner is provided with a plurality of discharging ends, the discharging ends correspond to the glue storage bins one to one, the discharging ends communicate with the glue storage bins, the hydraulic cylinder comprises a first cylinder body, a first piston and a transmission rod, and the first piston is slidably connected into the first cylinder body and fixedly connected with the transmission rod; one end of the transmission rod extends out of the first cylinder body and is connected with a plunger, the plunger is slidably connected into the glue storage bin, the plunger is in clearance fit with the inner wall of the glue storage bin, and the end, away from the first cylinder body, of the glue storage bin communicates with the sub-runner in the axial direction of the transmission rod; the mold assembly is connected with the machine table and comprises a plurality of cavities, the cavities correspond to the sub-runners in a one-to-one mode, and the sub-runners are communicated with the cavities. According to the embodiment of the utility model, uniform glue feeding amount can be realized.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molding machines, in particular to an injection molding machine. Background Art

[0002] Injection molding is a widely used processing method in modern manufacturing, especially suitable for mass production of plastic products with complex shapes and high precision requirements. Traditional injection molding machines are mainly composed of a glue injection system, a mold clamping system, a control system, etc., among which the glue injection system is responsible for injecting the molten plastic material into the mold cavity. In the existing technology, a one-mold multi-cavity structure is usually adopted. By setting up multiple branch channels, the glue from the main channel is diverted to multiple nozzles to perform glue injection in multiple mold cavities, thereby improving efficiency. However, this method is prone to uneven glue feeding in multiple branch channels, resulting in incomplete filling of individual products. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides an injection molding machine that can achieve uniform glue feeding and improve the yield rate.

[0004] According to an injection molding machine proposed by the utility model, it includes a main glue injection nozzle, a machine platform, multiple glue injection modules and a mold assembly, the main glue injection nozzle is connected to the machine platform, and a main flow channel connected to the main glue injection nozzle is provided in the machine platform; the glue injection module is connected to the machine platform, the glue injection module includes a glue storage bin, a hydraulic cylinder and a branch channel, the main flow channel has multiple discharge ends, the discharge ends correspond to the glue storage bin one by one, and the discharge ends are connected to the glue storage bin, the hydraulic cylinder includes a first cylinder body, a first piston and a transmission rod, the first A piston is slidably connected to the first cylinder body and fixed to the transmission rod. One end of the transmission rod extends out of the first cylinder body and is connected to a plunger. The plunger is slidably connected to the glue storage bin. The plunger and the inner wall of the glue storage bin are clearance-fitted. Along the axial direction of the transmission rod, one end of the glue storage bin away from the first cylinder body is connected to the diversion channel; the mold assembly is connected to the machine, and the mold assembly includes a plurality of cavities, the cavities correspond one-to-one to the diversion channels, and the diversion channels are connected to the cavities.

[0005] The injection molding machine according to the above embodiment of the utility model has at least the following beneficial effects:

[0006] The injection molding machine provided by the embodiment of the present invention is provided with a glue storage bin. The colloid enters the main flow channel from the main glue injection nozzle and is then diverted to each glue storage bin through multiple discharge ends until each glue storage bin is filled. After the glue storage bin is filled, the first piston is driven to move by the hydraulic cylinder so that the plunger pushes the colloid to the corresponding cavity, thereby achieving a uniform glue feeding amount, effectively preventing the problem of incomplete product filling caused by uneven glue feeding amount, and improving the yield rate. The precise matching design between the glue storage bin and the plunger ensures good sealing even under high pressure, prevents leakage, and further ensures the stability of the injection molding process. The parallel working mode of multiple injection modules greatly shortens the injection molding cycle and improves production efficiency.

[0007] According to some embodiments of the present invention, the first cylinder body has a maximum stroke, the transmission rod extends out of the first cylinder body at one end away from the plunger and is connected to a limiting member, the injection module also includes a pressure-maintaining limiting mechanism, the pressure-maintaining limiting mechanism is connected to the first cylinder body, the pressure-maintaining limiting mechanism can limit the movement of the limiting member so that the first piston moves a first stroke, the first stroke is less than the maximum stroke, and during the pressure-maintaining stage, the pressure-maintaining limiting mechanism moves so that the first piston can continue to move.

[0008] According to some embodiments of the present invention, the pressure-maintaining and limiting mechanism includes a second cylinder body and a second piston, the second cylinder body is connected to the side of the first cylinder body away from the plunger, the second piston is slidably connected in the second cylinder body, the axial direction of the second piston is the same as the axial direction of the first piston, the second cylinder body is provided with an oil port, the oil port is located on the side of the second piston close to the first cylinder body, the second cylinder body has a second stroke, the second stroke is smaller than the first stroke, and a through hole is provided on the side of the second cylinder body away from the first cylinder body, one end of the transmission rod passes through the second cylinder body, the second piston and the through hole in sequence and the limiting member is provided, and the limiting member can enter the through hole and abut the second piston.

[0009] According to some embodiments of the present invention, a threaded column is provided at the middle of one end of the transmission rod away from the plunger, and the limiting member includes a sleeve and an adjusting nut. The sleeve is sleeved on the threaded column and is limited by the adjusting nut.

[0010] According to some embodiments of the present invention, a positioning hole is provided on a side of the second piston close to the sleeve, the positioning hole is adapted to the shape of the sleeve, and at least one gasket is provided on the bottom wall of the positioning hole.

[0011] According to some embodiments of the present invention, the mold assembly includes a mold body and multiple injection nozzles, the injection nozzles are arranged on the mold body, the injection nozzles correspond to the mold cavities one by one, and the branch channels, the injection nozzles and the mold cavities are connected in sequence.

[0012] According to some embodiments of the present invention, the injection nozzle is connected to a needle valve assembly, which includes a piston assembly and a valve needle. The piston assembly is arranged on the mold body and connected to the compressed air circuit. One end of the valve needle is connected to the piston assembly, and the other end of the valve needle extends into the injection nozzle.

[0013] According to some embodiments of the present invention, the piston assembly includes a piston body and a fixed sleeve. The piston body is arranged in the mold body and can move back and forth in the mold body. The fixed sleeve is fixedly connected to the piston body through a thread, and one end of the valve needle is connected to the fixed sleeve.

[0014] According to some embodiments of the present invention, the needle valve assembly further includes a guide sleeve, which is disposed on the mold body, the valve needle passes through the guide sleeve, and the valve needle and the guide sleeve are slidably connected.

[0015] According to some embodiments of the present invention, the mold assembly also includes a connecting nozzle head, which is connected to the mold body. The connecting nozzle head is provided with multiple connecting channels, which correspond one-to-one to the branch channels, and the branch channels are connected to the injection nozzle through the connecting channels.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0018] Figure 1 Schematic diagram of an injection molding machine according to some embodiments of the present invention;

[0019] Figure 2 Schematic diagram of the partial structure of the injection molding machine of some embodiments of the present utility model;

[0020] Figure 3 A schematic diagram of an injection molding machine in accordance with some embodiments of the present invention in the first stage;

[0021] Figure 4 A schematic diagram of an injection molding machine in accordance with some embodiments of the present invention performing the second stage;

[0022] Figure 5 A schematic diagram of an injection molding machine in accordance with some embodiments of the present invention in the third stage;

[0023] Figure 6 Schematic diagram of the mold assembly of some embodiments of the present invention.

[0024] Wherein, the reference numerals:

[0025] Main glue injection nozzle 100;

[0026] Machine 200; Main channel 210;

[0027] Glue injection module 300; glue storage bin 310; flow channel 320; first cylinder 330; first piston 340; transmission rod 350; plunger 360; threaded column 370; sleeve 380; adjusting nut 390;

[0028] Second cylinder 400; through hole 401; second piston 410; positioning hole 411;

[0029] Cavity 510 ; mold body 520 ; injection nozzle 530 ; valve needle 540 ; piston body 550 ; fixing sleeve 560 ; guide sleeve 570 ; connecting nozzle head 580 ; connecting channel 581 . DETAILED DESCRIPTION

[0030] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0031] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0032] In the description of this utility model, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0033] In the description of this utility model, unless otherwise expressly defined, terms such as "set," "install," and "connect" should be interpreted broadly. Those skilled in the art can reasonably determine the specific meanings of these terms in the present utility model based on the specific content of the technical solution. In the description of this utility model, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with such embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of these terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in any one or more embodiments or examples. In the description of this specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with such embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of these terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0034] Reference Figures 1 to 6 According to the present invention, an injection molding machine includes a main glue injection nozzle 100, a machine platform 200, a plurality of glue injection modules 300 and a mold assembly. The main glue injection nozzle 100 is connected to the machine platform 200. A main flow channel 210 connected to the main glue injection nozzle 100 is provided in the machine platform 200; the glue injection module 300 is connected to the machine platform 200, and the glue injection module 300 includes a glue storage bin 310, a hydraulic cylinder and a branch channel 320. The main flow channel 210 has multiple discharge ends, and the discharge ends correspond to the glue storage bin 310 one by one, and the discharge ends are connected to the glue storage bin 310. The hydraulic cylinder includes a first cylinder body 330, a first piston 340 and a transmission rod 3 50. The first piston 340 is slidably connected to the first cylinder body 330 and fixed to the transmission rod 350. One end of the transmission rod 350 extends out of the first cylinder body 330 and is connected to the plunger 360. The plunger 360 is slidably connected to the glue storage bin 310. The plunger 360 and the inner wall of the glue storage bin 310 are clearance-fitted. Along the axial direction of the transmission rod 350, the end of the glue storage bin 310 away from the first cylinder body 330 is connected to the diverter channel 320; the mold assembly is connected to the machine 200, and the mold assembly includes a plurality of cavities 510. The cavities 510 correspond one-to-one to the diverter channels 320, and the diverter channels 320 are connected to the cavities 510.

[0035] It is understandable that the injection molding machine provided by the embodiment of the present invention is provided with a glue storage bin 310, and the colloid enters the main channel 210 from the main glue injection nozzle 100, and is then diverted to each glue storage bin 310 through multiple discharge ends until each glue storage bin 310 is filled. After the glue storage bin 310 is filled, the first piston 340 is driven to move by the hydraulic cylinder so that the plunger 360 pushes the colloid to the corresponding cavity 510, thereby achieving a uniform glue feeding amount, effectively preventing the problem of incomplete product filling caused by uneven glue feeding amount, and improving the yield rate. The precise matching design between the glue storage bin 310 and the plunger 360 ensures good sealing even under high pressure, prevents leakage, and further ensures the stability of the injection molding process. The parallel working mode of multiple injection modules 300 greatly shortens the injection molding cycle and improves production efficiency.

[0036] Further, refer to Figures 3 to 5 According to some embodiments of the present invention, the first cylinder 330 has a maximum stroke, and the end of the transmission rod 350 away from the plunger 360 extends out of the first cylinder 330 and is connected to a limiting member. The injection module 300 also includes a pressure-holding limiting mechanism, which is connected to the first cylinder 330. The pressure-holding limiting mechanism can limit the movement of the limiting member so that the first piston 340 moves a first stroke. The first stroke is less than the maximum stroke. During the pressure-holding stage, the pressure-holding limiting mechanism moves so that the first piston 340 can continue to move.

[0037] It is understandable that, since the volume of the colloid injected into the cavity 510 will shrink after cooling, it will also lead to incomplete filling of the product and low yield rate. Therefore, in order to solve the above technical problems, the embodiment of the present invention limits the moving stroke of the limiter by a pressure-holding limit mechanism, thereby limiting the first piston 340 from moving to the maximum stroke. When the first piston 340 moves the first stroke, the amount of colloid pushed by the plunger 360 can fill the cavity 510. During the pressure-holding stage, the volume of the colloid in the cavity 510 shrinks due to cooling. After a certain pressure-holding time, the pressure-holding limit mechanism moves to release the restriction on the limiter, allowing the limiter to continue to move, thereby allowing the first piston 340 to continue to move a certain stroke. The amount of colloid pushed by the plunger 360 can fill the missing part of the cavity 510, thereby achieving pressure-holding filling, ensuring the complete filling of the cavity 510, and improving the yield rate.

[0038] It should be noted that the volume of the glue storage bin 310 is designed according to the volume of the cavity 510, and the volume of the glue storage bin 310 should be larger than the volume of the cavity 510, so as to ensure that the colloid in the glue storage bin 310 can fill the cavity 510 completely, and reserve a certain amount of colloid for pressure maintenance and material replenishment to ensure the yield of finished products.

[0039] Further, refer to Figures 3 to 5According to some embodiments of the present invention, the pressure maintaining and limiting mechanism includes a second cylinder body 400 and a second piston 410. The second cylinder body 400 is connected to the side of the first cylinder body 330 away from the plunger 360. The second piston 410 is slidably connected to the second cylinder body 400. The axial direction of the second piston 410 is the same as the axial direction of the first piston 340. The second cylinder body 400 is provided with an oil port, which is located on the side of the second piston 410 close to the first cylinder body 330. The second cylinder body 400 has a second stroke, which is smaller than the first stroke. A through hole 401 is provided on the side of the second cylinder body 400 away from the first cylinder body 330. One end of the transmission rod 350 passes through the second cylinder body 400, the second piston 410 and the through hole 401 in sequence and is provided with a limiting member. The limiting member can enter the through hole 401 and abut the second piston 410.

[0040] It can be understood that before the pressure-maintaining feeding is performed, the second cylinder 400 injects pressurized oil through the oil port, so that the second piston 410 cannot move toward the first cylinder 330. The first cylinder 330 is connected to an oil circuit, which drives the first piston 340 to move through the oil circuit to drive the plunger 360 to push the colloid in the glue storage bin 310. At the same time, the first piston 340 drives the transmission rod 350 to move, thereby driving the limiter to move until the limiter enters the through hole 401 and abuts the second piston 410. Since the second piston 410 cannot move under the action of the pressurized oil, the limiter cannot continue to move, and thus the first piston 340 cannot continue to move. That is to say, even if the oil circuit continues to apply pressure to the first piston 340 through oil injection, the first piston 340 still cannot complete the maximum stroke, but can only maintain the first stroke. At this time, the amount of colloid pushed by the plunger 360 corresponding to the first stroke can fill the cavity 510. During the holding stage when the first piston 340 cannot move further, the volume of the colloid in the cavity 510 shrinks due to cooling. After a certain holding time, the second cylinder 400 discharges the pressurized oil through the oil port, so that the second piston 410 can move. Since the oil circuit continuously provides pressure to the first piston 340, the first piston 340 can continue to move under the drive of the oil circuit, and drives the limit member to push the second piston 410 to move through the transmission rod 350. The second stroke that the second piston 410 can move is the stroke that the first piston 340 can move. At this time, the amount of colloid pushed by the plunger 360 corresponding to the second stroke is the amount of colloid replenished to the cavity 510, thereby filling the space where the cavity 510 is short of material, thereby improving the yield rate.

[0041] It should be noted that in the embodiment of the present invention, the specific volume of the glue storage bin 310, the maximum stroke of the first cylinder 330, the first stroke of the second piston 410 and the second stroke of the second piston 410 are all designed according to the actual volume of the cavity 510 and are not specifically limited here.

[0042] It should be noted that in the embodiment of the present invention, the total stroke of the first piston 340 after moving the first stroke and the second stroke can be equal to the maximum stroke of the first cylinder 330, or it can be less than the maximum stroke of the first cylinder 330. It can be designed according to actual conditions and will not be elaborated here.

[0043] Further, refer to Figures 3 to 5 According to some embodiments of the present invention, a threaded column 370 is provided in the middle of one end of the transmission rod 350 away from the plunger 360, and the limiting member includes a sleeve 380 and an adjusting nut 390. The sleeve 380 is mounted on the threaded column 370 and is limited by the adjusting nut 390.

[0044] It is understandable that when injecting glue into multiple products at the same time, the amount of glue required before the pressure holding stage may be different for different products or the same product in different situations. If the injection amount is still unified, it may easily lead to the product being unqualified after the pressure holding and glue filling. Therefore, it is necessary to adjust the first stroke of the first piston 340 in the actual production process to adjust the amount of glue pushed by the plunger 360.

[0045] In order to solve the above technical problems, the embodiment of the present invention provides a threaded column 370 at the end of the transmission rod 350 away from the plunger 360, and sets the sleeve 380 on the threaded column 370, and limits the sleeve 380 by adjusting the nut 390, so that the moving stroke of the first piston 340 is limited by the cooperation of the sleeve 380 and the second piston 410, and the position of the sleeve 380 is adjusted by adjusting the position of the adjusting nut 390 to adjust the position of the sleeve 380, thereby adjusting the first stroke of the first piston 340, and then adjusting the amount of colloid pushed by the plunger 360 corresponding to the first stroke. Specifically, when the first stroke needs to be increased to increase the amount of glue injected, the adjusting nut 390 is screwed outward to move the adjusting nut 390 away from the second piston 410, allowing the sleeve 380 to move along the threaded column 370. When the first piston 340 moves under the drive of the oil circuit, the immobile second piston 410 pushes the sleeve 380 toward the adjusting nut 390, thereby increasing the distance between the sleeve 380 and the first piston 340. In other words, the first movable stroke of the first piston 340 is increased, thereby increasing the amount of glue injected. Similarly, when the first stroke needs to be decreased to reduce the amount of glue injected, the adjusting nut 390 is screwed inward to adjust the distance between the sleeve 380 and the first piston 340. This simple structure and convenient operation.

[0046] It should be noted that the adjustable range of the sleeve 380 does not exceed the size range of the threaded column 370. The actual size can be designed according to actual production requirements and is not specifically limited here.

[0047] Further, refer to Figures 3 to 5According to some embodiments of the present invention, a positioning hole 411 is provided on a side of the second piston 410 close to the sleeve 380 . The positioning hole 411 is adapted to the shape of the sleeve 380 , and at least one gasket is provided on the bottom wall of the positioning hole 411 .

[0048] It can be understood that the positioning hole 411 is provided to facilitate the fit between the second piston 410 and the sleeve 380. The gasket can not only play a buffering role, but also can reduce or increase the number of gaskets to adjust the distance between the sleeve 380 and the second piston 410, thereby adjusting the first stroke of the first piston 340.

[0049] Furthermore, according to some embodiments of the present invention, the pressure-maintaining limiting mechanism may also be other structural forms. For example, a block may be used to block the movement of the limiting member, and a driving structure such as a motor may be used to drive the block away from the limiting member so that the limiting member can continue to move, or other structural forms may be used. It can be determined according to actual production needs and will not be elaborated here.

[0050] Further, refer to Figure 6 According to some embodiments of the present invention, the mold assembly includes a mold body 520 and a plurality of injection nozzles 530. The injection nozzles 530 are arranged on the mold body 520. The injection nozzles 530 correspond one-to-one to the mold cavity 510. The branch channel 320, the injection nozzles 530 and the mold cavity 510 are connected in sequence.

[0051] Further, refer to Figure 6 According to some embodiments of the present invention, the injection nozzle 530 is connected to a needle valve assembly, which is used to open or block the injection nozzle 530. The needle valve assembly includes a piston assembly and a valve needle 540. The piston assembly is arranged on the mold body 520, and the piston assembly is connected to the compressed air circuit. One end of the valve needle 540 is connected to the piston assembly, and the other end of the valve needle 540 extends into the injection nozzle 530.

[0052] Further, refer to Figure 6 According to some embodiments of the present invention, the piston assembly includes a piston body 550 and a fixed sleeve 560. The piston body 550 is arranged in the mold body 520, and the piston body 550 can be driven by a compressed air circuit in the mold body 520 to move back and forth, thereby driving the valve needle 540 to move. The fixed sleeve 560 is fixedly connected to the piston body 550 through a thread, and one end of the valve needle 540 is connected to the fixed sleeve 560.

[0053] Further, refer to Figure 6According to some embodiments of the present invention, the needle valve assembly further includes a guide sleeve 570, which is disposed on the mold body 520, the valve needle 540 passes through the guide sleeve 570, and the valve needle 540 and the guide sleeve 570 are slidably connected, and the guide sleeve 570 guides the valve needle 540, ensuring that the valve needle 540 and the injection nozzle 530 are on the same axis, thereby enabling the injection nozzle 530 to be accurately opened or closed.

[0054] Further, refer to Figure 2 According to some embodiments of the present invention, the mold assembly also includes a connecting nozzle head 580, which is connected to the mold body 520. The connecting nozzle head 580 is provided with a plurality of connecting channels 581, and the connecting channels 581 correspond one-to-one to the branch channels 320. The branch channels 320 are connected to the injection nozzle 530 through the connecting channels 581.

[0055] The working principle of the embodiment of the present invention will be further described in detail below with reference to the accompanying drawings.

[0056] like Figure 3 The figure shows the first stage of the operation of the injection molding machine. In this first stage, the heated and melted glue is injected into the main channel 210 through the main glue injection nozzle 100, and is injected into each glue storage bin 310 through multiple discharge ends until each glue storage bin 310 is filled. At the same time, the valve needle 540 blocks the injection nozzle 530.

[0057] It should be noted that since the valve needle 540 blocks the injection nozzle 530, after the glue storage bin 310 is filled, the glue in the glue storage bin 310 cannot be injected into the mold cavity 510 through the injection nozzle 530, nor can it flow back to the branch channel 320. When the total glue amount is determined, the glue in the branch channel 320 can fill each glue storage bin 310 in turn, thereby achieving a uniform glue feeding amount, and there will be no situation where individual mold cavities 510 are filled too much or too little, thereby ensuring the yield of finished products.

[0058] like Figure 4The figure shows the second stage of the operation of the injection molding machine. In this second stage, the piston body 550 moves upward under the drive of the compressed air circuit to drive the valve needle 540 to move upward, thereby opening the injection nozzle 530. The first cylinder 330 drives the first piston 340 to move forward through the oil circuit, so that the plunger 360 pushes the colloid forward into the injection nozzle 530. The injection nozzle 530 injects the colloid into the mold cavity 510 until the limiter abuts the second piston 410. Since the second piston 410 cannot move forward under the action of the pressurized oil, the limiter cannot continue to move forward, so that the first piston 340 cannot continue to move forward under the drive of the oil circuit. At this time, the first piston 340 moves the first stroke, and the plunger 360 moves forward the first stroke accordingly and pushes the corresponding colloid into the injection nozzle 530, so that the injection nozzle 530 can just fill the mold cavity 510. After the cavity 510 is filled, the piston body 550 moves downward under the drive of the compressed air circuit to drive the valve needle 540 to move downward, thereby blocking the injection nozzle 530 to prevent leakage of the colloid. At the same time, the first piston 340 maintains a tendency to move forward under the pressure of the oil circuit, but cannot continue to move forward due to the obstruction of the second piston 410 to the limit member.

[0059] like Figure 5 The figure shows the third stage of the injection molding machine operation, namely the pressure holding stage. In this third stage, the volume of the colloid in the cavity 510 gradually decreases due to cooling. During this period of time when the volume of the colloid continues to decrease, the first piston 340 still maintains a tendency to move forward under the pressure of the oil circuit, that is, this period of time is the pressure holding time. After the volume of the colloid in the cavity 510 is completely reduced, that is, after the pressure holding time ends, the injection nozzle 530 is turned on, and the second cylinder 400 discharges pressurized oil through the oil port, allowing the second piston 410 to move, thereby allowing the first piston 340 to continue to move forward under the drive of the oil circuit. The second stroke that the second piston 410 can move is the stroke that the first piston 340 can continue to move. The amount of colloid pushed by the plunger 360 corresponding to the second stroke is the amount of colloid replenished to the cavity 510, thereby filling the space in the cavity 510 where the material is missing, thereby completing the pressure holding and filling. After the pressure holding and filling are completed, the piston body 550 moves downward under the drive of the compressed air circuit to drive the valve needle 540 to move downward, thereby blocking the injection nozzle 530.

[0060] It should be noted that, in the embodiment of the present invention, the holding time can be determined according to actual production needs and is not specifically limited here.

[0061] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. An injection molding machine, characterized in that: include: Main injection nozzle; A machine platform, wherein the main glue injection nozzle is connected to the machine platform, and a main flow channel connected to the main glue injection nozzle is provided in the machine platform; a plurality of glue injection modules, wherein the glue injection modules are connected to the machine platform, the glue injection modules include a glue storage bin, a hydraulic cylinder and a branch channel, the main channel has a plurality of discharge ends, the discharge ends correspond to the glue storage bins one by one, and the discharge ends are connected to the glue storage bins, the hydraulic cylinder includes a first cylinder body, a first piston and a transmission rod, the first piston is slidably connected to the first cylinder body and fixed to the transmission rod, one end of the transmission rod extends out of the first cylinder body and is connected to a plunger, the plunger is slidably connected to the glue storage bin, the plunger is clearance-fitted with the inner wall of the glue storage bin, and along the axial direction of the transmission rod, the end of the glue storage bin away from the first cylinder body is connected to the branch channel; A mold assembly is connected to the machine platform, and the mold assembly includes a plurality of cavities, the cavities correspond to the branch channels one by one, and the branch channels are connected to the cavities.

2. The injection molding machine according to claim 1, characterized in that The first cylinder has a maximum stroke, and the transmission rod extends out of the first cylinder at one end away from the plunger and is connected to a limiting member. The injection module also includes a pressure-holding limiting mechanism, which is connected to the first cylinder. The pressure-holding limiting mechanism can limit the movement of the limiting member so that the first piston moves a first stroke, and the first stroke is less than the maximum stroke. During the pressure-holding stage, the pressure-holding limiting mechanism moves so that the first piston can continue to move.

3. The injection molding machine according to claim 2, characterized in that The pressure-maintaining and limiting mechanism includes a second cylinder body and a second piston, the second cylinder body is connected to the side of the first cylinder body away from the plunger, the second piston is slidably connected to the second cylinder body, the axial direction of the second piston is the same as the axial direction of the first piston, the second cylinder body is provided with an oil port, the oil port is located on the side of the second piston close to the first cylinder body, the second cylinder body has a second stroke, the second stroke is smaller than the first stroke, the side of the second cylinder body away from the first cylinder body is provided with a through hole, one end of the transmission rod passes through the second cylinder body, the second piston and the through hole in sequence and is provided with the limiting member, and the limiting member can enter the through hole and abut the second piston.

4. The injection molding machine according to claim 3, characterized in that A threaded column is provided at the middle of one end of the transmission rod away from the plunger. The limiting member includes a shaft sleeve and an adjusting nut. The shaft sleeve is sleeved on the threaded column and is limited by the adjusting nut.

5. The injection molding machine according to claim 4, characterized in that A positioning hole is provided on a side of the second piston close to the shaft sleeve. The positioning hole is adapted to the shape of the shaft sleeve, and at least one gasket is provided on the bottom wall of the positioning hole.

6. The injection molding machine according to claim 1, characterized in that The mold assembly includes a mold body and a plurality of injection nozzles. The injection nozzles are arranged on the mold body. The injection nozzles correspond to the mold cavities one by one. The branch channels, the injection nozzles and the mold cavities are connected in sequence.

7. The injection molding machine according to claim 6, characterized in that The injection nozzle is connected to a needle valve assembly, which includes a piston assembly and a valve needle. The piston assembly is arranged on the mold body and connected to the compressed air circuit. One end of the valve needle is connected to the piston assembly, and the other end of the valve needle extends into the injection nozzle.

8. The injection molding machine according to claim 7, characterized in that The piston assembly includes a piston body and a fixed sleeve. The piston body is arranged in the mold body and can move back and forth in the mold body. The fixed sleeve is fixedly connected to the piston body through a thread, and one end of the valve needle is connected to the fixed sleeve.

9. The injection molding machine according to claim 8, characterized in that The needle valve assembly further includes a guide sleeve, which is arranged on the mold body. The valve needle passes through the guide sleeve, and the valve needle and the guide sleeve are slidably connected.

10. The injection molding machine according to claim 6, characterized in that The mold assembly also includes a connecting nozzle head, which is connected to the mold body. The connecting nozzle head is provided with a plurality of connecting channels, and the connecting channels correspond one-to-one to the branch channels. The branch channels are connected to the injection nozzle through the connecting channels.

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