Mould core retreating mechanism based on micro-foaming process

Abstract

The utility model belongs to the technical field of mold design and manufacturing, and particularly discloses a mold core retreating mechanism based on a micro-foaming process, which comprises a front mold oil cylinder, a front mold driving unit, a front mold hot nozzle, a front mold forming mold cavity, a rear mold oil cylinder, a rear mold driving unit, a rear mold forming mold cavity and an ejector sleeve structure, the front mold oil cylinder is installed on a front mold, the output end of the front mold oil cylinder moves in the vertical direction, and the front mold driving unit is connected with the output end of the front mold oil cylinder. The front mold oil cylinder push rod is driven by the front mold oil cylinder to sequentially drive the hot runner fixing plate and the hot runner plate to move, the front mold hot nozzle is driven to move towards or away from the ejector sleeve structure in the vertical direction, and the thickness of an injection molding cavity formed by the front mold hot nozzle and the ejector sleeve structure is changed; the weight reduction amount of the product under the micro-foaming process is adjusted, and the quality of the product is improved by adopting the micro-foaming process.

Description

Technical Field

[0001] The utility model belongs to the technical field of mold design and manufacturing, and particularly relates to a mold core retreat mechanism based on a micro-foaming process. Background Art

[0002] The full name of the micro-foaming process is micro-foaming injection molding process. It forms micron-sized bubbles by introducing supercritical fluid (such as carbon dioxide or nitrogen) into the plastic melt, thereby achieving lightweight and performance improvement of the parts. It has the advantages of lightweight, dimensional stability, shortened molding cycle, improved surface quality, reduced internal stress and environmental protection.

[0003] However, the current micro-foaming process does not use a core-retracting mechanism to achieve its goal, and only limits its foaming by the size of the cavity. However, without a core-retracting mechanism, the existing micro-foaming process has a very limited effect on product weight reduction when manufacturing products. Moreover, without a core-retracting mechanism, the amount of weight reduction through micro-foaming cannot be adjusted, which seriously affects the quality of the products made by the micro-foaming process. Utility Model Content

[0004] The utility model provides a mold core retreat mechanism based on the micro-foaming process, which aims to achieve a change in wall thickness from thin to thick through the core retreat mechanism. Combined with the micro-foaming process injection molding, the product can achieve the expected wall thickness, which can reduce the product weight to a greater extent. The core retreat stroke is used to adjust the amount of product weight reduction, and finally the micro-foaming process is combined to improve the quality of the product.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] The mold core retreat mechanism based on the micro-foaming process includes a front mold cylinder, a front mold drive unit, a front mold hot nozzle, a front mold forming cavity, a rear mold cylinder, a rear mold drive unit, a rear mold forming cavity and a nozzle sleeve structure;

[0007] The front mold oil cylinder is installed on the front mold, and the output end of the front mold oil cylinder moves in the vertical direction.

[0008] The front mold driving unit is connected to the output end of the front mold oil cylinder, the front mold hot nozzle is installed on the front mold driving unit, and the front mold forming cavity is formed on the front mold hot nozzle;

[0009] The rear mold oil cylinder is installed on the rear mold, and the output end of the rear mold oil cylinder moves in the horizontal direction.

[0010] The rear mold driving unit is connected to the output end of the rear mold oil cylinder, and the rear mold driving unit moves in the vertical direction. The sleeve structure is installed on the rear mold driving unit, and the rear mold forming cavity is formed on the sleeve structure.

[0011] The front mold hot nozzle and the nozzle sleeve structure correspond to each other in the vertical direction, and the front mold forming cavity and the rear mold forming cavity form an injection cavity. The front mold drive unit is driven by the front mold cylinder, thereby driving the front mold hot nozzle to move away from or toward the nozzle sleeve structure, or the rear mold drive unit is driven by the output end of the rear mold cylinder, thereby driving the nozzle sleeve structure to move away from or toward the front mold hot nozzle.

[0012] Preferably, the front mold includes a front mold fixing plate, a front mold drive unit fixing plate, a front mold bottom plate and a front mold drive unit. The front mold fixing plate, the front mold drive unit fixing plate and the front mold bottom plate are connected in sequence along the vertical direction to form an upper frame. The front mold drive unit is arranged in the upper frame and connected to the front mold hot nozzle, which is used to drive the front mold hot nozzle to move in the vertical direction, so that the front mold hot nozzle moves toward or away from the nozzle barrel structure in the vertical direction.

[0013] Preferably, the front mold drive unit includes a front mold cylinder; the front mold drive unit fixing plate is a front mold cylinder fixing plate, the fixed end of the front mold cylinder is installed on the side wall of the cylinder fixing plate in the vertical direction, the output end of the front mold cylinder is vertically upward and connected to the hot runner fixing plate, the bottom of the hot runner fixing plate is fixedly connected to the hot runner plate in the vertical direction, the front mold A plate is fixedly mounted below the hot runner plate in the vertical direction, the front mold bottom plate is fixedly sleeved on the front mold A plate, the front mold hot nozzle is installed on the hot runner plate, and sleeved on the front mold A plate.

[0014] Furthermore, the output end of the front mold oil cylinder is provided with a front mold push rod, which is vertically upward and connected to the hot runner fixing plate.

[0015] Preferably, the front mold A plate, the hot runner plate and the hot runner fixing plate are all provided with hot runner guide pillars, and the hot runner plate and the hot runner fixing plate are both slidably connected to the hot runner guide pillars.

[0016] Preferably, the bottom surface of the front mold A plate has a parting surface A.

[0017] Preferably, a front mold placement cavity is provided inside the hot runner plate, a hot runner system is installed inside the front mold placement cavity, and the hot runner system is in contact with the front mold hot nozzle.

[0018] Preferably, a limiting plate is installed on the top of the front mold fixing plate, and the limiting plate is located above the hot runner plate fixing plate to limit the floating plate and the hot runner plate fixing plate.

[0019] Preferably, the rear mold includes a rear mold B plate and a rear mold driving unit, and the sleeve structure is sleeved on the rear mold B plate and driven by the rear mold driving unit to move the sleeve structure toward or away from the front mold hot nozzle in a vertical direction.

[0020] Preferably, the rear mold further comprises a rear mold floating plate, a square iron, a pad, a return pin, a push rod and a spring;

[0021] The rear mold B plate is vertically mounted with the rear mold floating plate, which is vertically mounted with a square iron; the pad is vertically connected to the square iron; the rear mold B plate, the rear mold floating plate, the square iron, and the pad are collectively sleeved with return pins, and springs are sleeved on the return pins of the square iron and the pad; the push rod is vertically sleeved with the rear mold B plate, the rear mold floating plate, the square iron, and the pad in sequence; and the lower end of the spring is in contact with the rear mold drive unit;

[0022] A sleeve structure is placed between the square iron and the pad.

[0023] Preferably, a rear mold placement cavity is provided in the pad, a rear mold installation cavity is opened on the square iron, the rear mold placement cavity and the rear mold installation cavity form a combined cavity, and a rear mold driving unit is placed in the combined cavity.

[0024] Preferably, the rear mold B plate, the rear mold floating plate and the square iron are further fixed by a first limiting screw, and the rear mold floating plate and the square iron are further fixed by a second limiting screw.

[0025] Preferably, the sleeve structure includes a sleeve and a sleeve needle, the upper end of the sleeve needle is vertically sleeved in the sleeve, the top of the rear mold B plate has a parting surface B corresponding to the parting surface A, the top of the sleeve extends out of the parting surface B and corresponds to the front mold hot nozzle, and the rear mold driving unit drives the sleeve and the sleeve needle at the same time, so that the sleeve and the sleeve needle move simultaneously in the vertical direction toward or away from the front mold hot nozzle.

[0026] Preferably, the rear mold driving unit includes an upper ejector plate, an upper oblique shovel, a lower ejector plate, and a lower oblique shovel.

[0027] The lower layer oblique shovel, lower layer ejector plate, upper layer oblique shovel, and upper layer ejector plate are arranged in sequence along the vertical direction, and the sleeve is sleeved on the upper layer ejector plate, and the sleeve needle is sleeved on the lower layer ejector plate. A bracket is installed on the rear mold, and a rear mold driving mechanism is provided on the bracket. The rear mold driving mechanism is used to simultaneously drive the upper layer oblique shovel and the lower layer oblique shovel, so that the sleeve and the sleeve needle move toward or away from the front mold hot nozzle at the same time along the vertical direction.

[0028] Preferably, both the upper layer oblique shovel and the lower layer oblique shovel have inclined surfaces, and the two inclined surfaces are parallel in the vertical direction.

[0029] Preferably, a mounting cavity is provided on the square iron, the upper ejector plate is mounted in the mounting cavity, and the bottom of the spring is in contact with the lower ejector plate.

[0030] Preferably, the rear mold driving mechanism includes a rear mold cylinder, a rear mold cylinder push rod, a rear mold cylinder fixed block and a push plate; the fixed end of the rear mold cylinder is installed on the bracket, the output end of the rear mold cylinder is connected to the push plate in the horizontal direction, the push plate extends in the vertical direction, and the two ends of one side wall of the push plate are respectively connected to the upper oblique shovel and the lower oblique shovel.

[0031] The beneficial effects of the utility model are:

[0032] (1) The utility model utilizes the front mold oil cylinder to drive the front mold oil cylinder push rod to drive the hot runner fixed plate to move, and then drive the hot runner plate to move, and then drive the front mold hot nozzle to move in the vertical direction toward or away from the nozzle sleeve structure, so that the thickness of the injection cavity formed by the front mold hot nozzle and the nozzle sleeve structure changes; thereby, when the thickness of the injection cavity is changed, the amount of weight loss of the product under the micro-foaming process is adjusted, thereby ensuring that when the device is used, the micro-foaming process is used to improve the quality of the product;

[0033] (2) The present invention also utilizes the rear mold oil cylinder to drive the rear mold oil cylinder push rod, so that when the rear mold oil rod push rod is extended and retracted, it drives the lower layer oblique shovel and the upper layer oblique shovel to move at the same time, and due to the inclined surface effect of the upper layer oblique shovel and the lower layer oblique shovel, the horizontal direction movement of the rear mold oil cylinder push rod driven by the rear mold oil cylinder is converted into the vertical direction movement of the upper layer oblique shovel and the lower layer oblique shovel, thereby driving the sleeve and the sleeve needle to move in the vertical direction, that is, the sleeve structure moves in the vertical direction relative to the front mold hot nozzle, so that the thickness of the injection cavity formed by the front mold hot nozzle and the sleeve structure changes; thereby, when the thickness of the injection cavity is changed, the amount of weight loss of the product under the micro-foaming process is adjusted, thereby ensuring that when using this device, the micro-foaming process is used to improve the quality of the product;

[0034] (3) The utility model adopts an injection molding machine connecting rod and a push rod to connect. The push rod moves toward the parting surface A, driving the rear mold B plate to move toward the front mold hot nozzle, thereby driving the buckle machine and the rear mold floating plate to move toward the front hot nozzle. When the rear mold floating plate reaches the preset formation, it is hard-limited by the second limit screw, and the synchronous buckle machine is released after reaching the preset stroke, so that the rear mold floating plate stops moving, and the push rod and the rear mold B plate continue to move forward until they reach the stroke and stop. At this time, the product falls, and the injection molding operation of a product is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of the structure of the product produced by this utility model;

[0036] Figure 2 This is a schematic diagram of the structure of the product produced by the utility model from another perspective;

[0037] Figure 3 This is a schematic structural diagram of the front mold in the utility model;

[0038] Figure 4 This is a schematic structural diagram of the rear mold in the utility model;

[0039] Figure 5 This is a cross-sectional view of the front mold and the rear mold in the present invention after they are closed together;

[0040] Figure 6 This is a side sectional view of the front mold and the rear mold after they are closed together;

[0041] Figure 7 for Figure 5 Cross-sectional view of the middle front mold in front view;

[0042] Figure 8 for Figure 5 Cross-sectional view of the middle rear mold in front view;

[0043] Figure 9 This is a schematic structural diagram of the sleeve and rear mold drive unit of the utility model;

[0044] Figure 10 for Figure 9 Cross-sectional view in

[0045] Figure 11 This is a cross-sectional view of the sleeve, sleeve needle and front mold hot nozzle in the utility model;

[0046] Figure 12 This is a side sectional view of the front mold and the rear mold after they are closed together;

[0047] Figure 13 It is a cross-sectional view of the utility model when the front mold and the rear mold are closed and viewed from the side from another perspective;

[0048] Figure 14 It is a cross-sectional view of the utility model when the front mold and the rear mold are closed and viewed from the side at a third perspective;

[0049] In the figure: front mold 1; limit plate 101; front mold fixing plate 102; hot runner fixing plate 103; front mold cylinder push rod 104; front mold cylinder 105; hot runner plate 106; front mold A plate 107; hot runner guide pillar 108; hot runner system 109; front mold cylinder fixing plate 110; front mold hot nozzle 111; flange 112; back mold 2; upper ejector plate 201; upper inclined shovel 202; spring 203; lower Ejector plate 204; lower layer oblique shovel 205; sleeve 206; sleeve needle 207; square iron 208; rear mold cylinder 209; rear mold cylinder push rod 210; rear mold cylinder fixing block 211; push plate 212; rear mold B plate 213; buckle machine 214; rear mold floating plate 215; pad 216; ejector rod 217; return pin 218; first limit screw 219; second limit screw 220; parting surface A 31; parting surface B 32; parting surface 3. DETAILED DESCRIPTION

[0050] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0051] The injection molding process used in the present invention is a micro-foaming process in the prior art. When injecting, the wall thickness of the injection cavity is first ensured to be Q. After the injection is completed, the mold core retreat mechanism in the present invention is used to achieve a wall thickness change of Q+P. Finally, the foaming process is used to make the wall thickness of the product reach Q+P, that is, Figure 1 As shown, its material is HDPE (high-density polyethylene), and its top wall thickness is Q+P. The unit of wall thickness depends on the actual situation. In this embodiment, the unit is mm;

[0052] In the utility model, a hot runner needle valve is used to directly feed glue into the hot nozzle of the front mold. The hot runner needle valve is arranged on the hot runner system of the front mold.

[0053] It should also be noted that the hot runner system is mainly used to add and heat the raw materials entering the front mold hot nozzle, so that the raw materials entering the front mold hot nozzle meet the usage requirements. For this reason, the specific structure of the hot runner system is not elaborated in detail in this article.

[0054] The micro-foaming process adopted by the present invention is specifically a core-recessed micro-foaming process, which is an efficient and environmentally friendly molding process, making greater contributions to achieving sustainable development. The application field of core-recessed foaming is very wide, mainly used in the fields of automobiles, electronics, home appliances, etc.; among them, in the automotive field, core-recessed foaming can be used to manufacture automobile seats, door panels, dashboards and other components to achieve the goals of lightweighting, energy saving and emission reduction.

[0055] Example 1

[0056] like Figure 1-14As shown, the mold core retreat mechanism based on the micro-foaming process includes a front mold cylinder 105, a front mold drive unit, a front mold hot nozzle 111, a front mold forming cavity, a rear mold cylinder 209, a rear mold drive unit, a rear mold forming cavity and a nozzle sleeve structure;

[0057] The front mold oil cylinder 105 is installed on the front mold 1, and the output end of the front mold oil cylinder 105 moves in the vertical direction.

[0058] The front mold driving unit is connected to the output end of the front mold oil cylinder 105, and the front mold hot nozzle 111 is installed on the front mold driving unit. The front mold forming cavity is formed on the front mold hot nozzle 111;

[0059] The rear mold oil cylinder 209 is installed on the rear mold 2, and the output end of the rear mold oil cylinder 209 moves in the horizontal direction.

[0060] The rear mold driving unit is connected to the output end of the rear mold oil cylinder 209, and the rear mold driving unit moves in the vertical direction. The sleeve structure is installed on the rear mold driving unit, and the rear mold forming cavity is formed on the sleeve structure.

[0061] The front mold hot nozzle unit 111 and the nozzle sleeve structure correspond to each other in the vertical direction. The front mold forming cavity and the rear mold forming cavity form an injection cavity. The front mold drive unit is driven by the front mold cylinder 105, thereby driving the front mold hot nozzle unit 111 to move away from or toward the nozzle sleeve structure, or the output end of the rear mold cylinder 209 drives the rear mold drive unit, thereby driving the nozzle sleeve structure to move away from or toward the front mold hot nozzle unit.

[0062] The front mold 1 includes a front mold fixing plate 102, a front mold drive unit fixing plate, a front mold bottom plate and a front mold drive unit. The front mold fixing plate 102, the front mold drive unit fixing plate and the front mold bottom plate are connected in sequence in the vertical direction to form an upper frame. The front mold drive unit is arranged in the upper frame and connected to the front mold hot nozzle 111, which is used to drive the front mold hot nozzle 111 to move in the vertical direction, so that the front mold hot nozzle 111 moves in the vertical direction toward or away from the nozzle barrel structure, and finally changes the thickness of the injection cavity.

[0063] The front mold driving unit includes a front mold cylinder 105, and the front mold driving unit fixing plate is the front mold cylinder fixing plate 110. The fixed end of the front mold cylinder 105 is installed on the side wall of the cylinder fixing plate 110 in the vertical direction. The front mold cylinder 105 is provided with a front mold cylinder push rod 104. The front mold oil rod push rod 104 is vertically upward and connected to the hot runner fixing plate 103. The bottom of the hot runner fixing plate 103 is fixedly connected to the hot runner plate 106 in the vertical direction. The front mold A plate 107 is fixed in the vertical direction below the hot runner plate 106. The front mold A plate 107 is movably sleeved in the front mold bottom plate, and the front mold hot nozzle 111 is sleeved on the front mold A plate 107.

[0064] Hot runner guide pillars 108 are commonly provided on the front mold A plate 107 , the hot runner plate 106 and the hot runner fixed plate 103 , and the hot runner plate 106 and the hot runner fixed plate 103 are both slidably connected to the hot runner guide pillars 108 .

[0065] The bottom surface of the front mold A plate 107 has a parting surface A 31 .

[0066] A placement cavity is provided inside the hot runner plate 106 , and a hot runner system 109 is installed inside the placement cavity. The hot runner system 109 is in contact with the front mold hot nozzle 111 and is used to cool and shape the product flowing through the front mold hot nozzle 111 .

[0067] A limiting plate 101 is installed on the top of the front mold fixing plate 102 . The limiting plate 101 is located above the hot runner plate fixing plate 103 to limit the floating plate 105 and the hot runner plate fixing plate 103 .

[0068] It should be noted that a flange 102 is provided on the hot runner system 109 , and the flange 102 is located on the top of the hot runner fixing plate 103 .

[0069] The rear mold 2 includes a rear mold B plate 213 and a rear mold driving unit. The sleeve structure is mounted on the rear mold B plate 213 and is driven by the rear mold driving unit to move the sleeve structure vertically toward or away from the front mold hot nozzle 111, ultimately changing the thickness of the injection cavity.

[0070] The rear mold further includes a rear mold floating plate 215, a square iron 208, a pad 216, a return pin 218, a push rod 217 and a spring 203;

[0071] The rear mold B plate 213 is installed with the rear mold floating plate 215 in the vertical direction, and the rear mold floating plate 215 is installed with the square iron 208 in the vertical direction; the pad 216 is connected with the square iron 208 in the vertical direction, specifically: the rear mold B plate 213 is installed with the rear mold floating plate 215 in the vertical direction through the buckle machine 214, and the rear mold floating plate 215 is installed with the square iron 208 in the vertical direction, and the rear mold floating plate 215 moves relative to the square iron 208, that is, the two are in contact or there is a gap, and the square iron 208 is connected with the buckle machine 214; more specifically, further The buckle machine 4 has two buckle machine fixed ends and one buckle machine movable end, and the buckle machine movable end is connected to the two buckle machine fixed ends, and one buckle machine fixed end is connected to the rear mold B plate 213, the other buckle machine fixed end is connected to the square iron 208, and the buckle machine movable end is connected to the rear mold floating plate 215; the rear mold floating plate 215 and the square iron 208 are connected by a second limit screw 220. Specifically, the buckle machine 4 adopts a commercially available product, for example, model Z3-1; for this reason, the specific structure and working principle are not introduced;

[0072] The backing plate 216 is vertically connected to the square iron 208. The rear mold B plate 213, the rear mold floating plate 215, the square iron 208, and the backing plate 216 are collectively sleeved with the return pin 218. The return pins of the square iron 208 and the backing plate 216 are sleeved with a spring 203. The top rod 217 is vertically sleeved on the rear mold B plate 213, the rear mold floating plate 215, the square iron 208, and the backing plate 216 in sequence. The lower end of the spring 203 is in contact with the rear mold drive unit.

[0073] A sleeve structure is placed between the square iron 208 and the backing plate 216, which is used to drive the sleeve structure to move vertically toward or away from the front mold hot nozzle 111, ultimately changing the thickness of the injection cavity. Specifically, a rear mold placement cavity is provided in the backing plate 216, and a rear mold mounting cavity is provided on the square iron 218. The rear mold placement cavity and the rear mold mounting cavity form a combined cavity, and the rear mold drive unit is placed in the combined cavity.

[0074] The rear mold B plate 213 , the rear mold floating plate 215 , and the square iron 208 are further fixed by a first limiting screw 219 , and the rear mold floating plate 215 and the square iron 208 are further fixed by a second limiting screw 220 .

[0075] The sleeve structure includes a sleeve 206 and a sleeve needle 207. The upper end of the sleeve needle 207 is vertically sleeved in the sleeve 206. The top of the rear mold B plate 216 has a parting surface B32 corresponding to the parting surface A31, and the parting surface A31 becomes the parting surface 3 after contacting the parting surface B32. The top of the sleeve 206 extends out of the parting surface B32 and corresponds to the front mold hot nozzle sleeve 111.

[0076] The rear mold driving unit includes an upper ejector plate 201, an upper oblique shovel 202, a lower ejector plate 204, and a lower oblique shovel 205.

[0077] The lower oblique shovel 205, the lower ejector plate 204, the upper oblique shovel 202, and the upper ejector plate 201 are arranged in sequence along the vertical direction. An installation cavity is opened on the square iron 208. The upper ejector plate 201 is installed in the installation cavity, and the bottom of the spring 203 is in contact with the lower ejector plate 204. The upper ejector plate 201 is sleeved with the sleeve 206, and the lower ejector plate 205 is sleeved with the sleeve needle 207. A bracket is installed on the rear mold 2, and a rear mold driving mechanism is provided on the bracket. The rear mold driving mechanism is used to simultaneously drive the upper oblique shovel 202 and the lower oblique shovel 205, so that the sleeve 206 and the sleeve needle 207 move simultaneously along the vertical direction toward or away from the front mold hot nozzle 111, and finally change the thickness of the injection cavity.

[0078] Both the upper layer oblique shovel 202 and the lower layer oblique shovel 205 have inclined surfaces, and the two inclined surfaces are parallel in the vertical direction.

[0079] The rear mold driving mechanism includes a rear mold cylinder 209, a rear mold cylinder push rod 210, a rear mold cylinder fixed block 211 and a push plate 212; the fixed end of the rear mold cylinder 209 is installed on the bracket through the rear mold cylinder fixed block 211, and the rear mold cylinder push rod 210 on the rear mold cylinder 206 is connected to the push plate 212 in the horizontal direction. The push plate 212 extends in the vertical direction, and the two ends of one side wall of the push plate 212 are respectively connected to the upper inclined shovel 202 and the lower inclined shovel 205.

[0080] This mold is produced in the following ways:

[0081] After the injection molding of the product is completed, the parting surface 3 is opened (the parting surface 3 is connected to the flange 112 on the front mold 1 by an external device, and then driven by the device to open the front mold 1 and the rear mold 2, that is, the parting surface 3 is opened), that is, the parting surface A 31 and the parting surface B 32 phase separation, the source power comes from the injection molding machine connecting rod, the connecting rod is connected to the ejector rod 11, the ejector rod 11 moves toward the parting surface B32, driving the rear mold B plate 213 to move forward, and at the same time driving the buckle machine 214 and the rear mold floating plate 215 to move forward, the sleeve needle 207 and the return needle 218 are fixed between the lower ejector plate 204, so they also move forward with the rear mold B plate 213 (the rear mold B plate 213 drives the sleeve needle 207 to move together so that the sleeve 206 also assists the rear mold B plate 213 in applying ejection force during the product ejection process to prevent the product from being too strong during the buckle process, causing the product mouth to deform). After the rear mold floating plate 215 reaches the preset stroke, it is hard-limited by the second limit screw 220, and the synchronous buckle machine 214 also reaches the preset stroke and is released, causing the rear mold floating plate 215 to stop moving, and the ejector rod 217 and the rear mold B plate 213 continue to move forward until they stop after reaching the stroke (also by Figure 14 The first limit screw 211 in the control stroke) causes the product to fall.

[0082] This mold can achieve changes in the thickness of the injection cavity under two different conditions, as follows:

[0083] The first one,

[0084] Step 1: Before injection, the mold is in the clamped state, the front mold cylinder 105 is in the contracted state, and there is a gap between the limit block 101 and the substrate surface on the injection molding machine, which is defined as Q (reserved for the back movement of the front mold hot nozzle 111 in the later stage). Therefore, the clamping force of the front mold 1 is supported by the injection molding machine nozzle (for this reason, the injection molding machine nozzle must be supported against the front mold 1 before the device is used), thereby ensuring that the injection cavity wall thickness is P;

[0085] Step 2, micro-foaming process injection molding, after the injection molding is completed, the injection molding machine nozzle retreats a distance Q, the front mold hot nozzle 111 pushes the front mold cylinder push rod 104 on the front mold oil cylinder 105 to push the hot runner fixed plate 103 to move, so that the hot runner plate 106 moves, and finally the front mold hot nozzle 111 moves backward a distance Q, that is, the distance between the front mold hot nozzle 111 and the nozzle barrel structure is Q, and finally the product is foamed to make the wall thickness reach P+Q.

[0086] Step 3: After cooling, eject the product and then close the mold again. After the mold closing is completed, the front mold cylinder 105 retracts the front mold cylinder push rod 104, causing the hot runner fixed plate 103 and the hot runner plate 106 to move back, thereby pulling back the front mold hot nozzle 16 (the wall thickness becomes P again), and the injection molding machine nozzle presses against the mold to start the next cycle.

[0087] Regarding the stroke P, the mold reserves a solution for adjusting the core retreat stroke, and the floating stroke of the front mold hot nozzle 111 can be achieved by changing the thickness of the front mold limit block 1.

[0088] The second type

[0089] Step 1. After the mold is closed, the rear mold cylinder 209 is filled with oil to move the rear mold cylinder push rod 210, thereby moving the push plate 206, so that the lower layer oblique shovel 205 and the upper layer oblique shovel 202 move at the same time, and the lower layer oblique shovel 205 and the upper layer oblique shovel 202 move toward the center of gravity of the mold. Since there are inclined surfaces between the upper layer oblique shovel 202 and the upper layer ejector plate 201 and between the lower layer oblique shovel 205 and the lower layer ejector plate 204, the upper layer ejector plate 201 and the lower layer ejector plate 204 are driven to move upward at the same time, so that the sleeve 206 and the sleeve needle 207 move forward at the same time. The hot nozzle 111 moves in the direction of Q, so that the wall thickness of the new injection cavity becomes P, and the mold is closed for injection. After the injection is completed, the rear mold cylinder 209 drives the upper inclined shovel 202 and the lower inclined shovel 205 to retreat. Under the action of the spring 203, the upper ejector plate 201 and the lower ejector plate 204 move toward the rear mold direction by Q (it should be noted that: when the spring 203 is assembled in the mold, a certain pre-pressure will be applied to the spring 203, so that the spring 203 is in a compressed state), so that the wall thickness of the injection cavity is restored to Q+P. The final product is foamed to a wall thickness of Q+Pmm.

[0090] It should be noted that: for the same stroke Q, the stroke of the core retreat mechanism of the rear mold 2 can also be achieved by adjusting the strokes of the upper inclined shovel 202 and the lower inclined shovel 205.

[0091] In addition, it should be noted that the vertical and horizontal directions in this device are only for reference in the drawings. In actual operation, the mold needs to be placed flat.

[0092] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments and that various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.

Claims

1. The mold core retreat mechanism based on the micro-foaming process is characterized by: It includes front mold oil cylinder, front mold drive unit, front mold hot nozzle, front mold forming cavity, rear mold oil cylinder, rear mold drive unit, rear mold forming cavity and nozzle sleeve structure; The front mold oil cylinder is installed on the front mold, and the output end of the front mold oil cylinder moves in the vertical direction. The front mold driving unit is connected to the output end of the front mold oil cylinder, the front mold hot nozzle is installed on the front mold driving unit, and the front mold forming cavity is formed on the front mold hot nozzle; The rear mold oil cylinder is installed on the rear mold, and the output end of the rear mold oil cylinder moves in the horizontal direction. The rear mold driving unit is connected to the output end of the rear mold oil cylinder, and the rear mold driving unit moves in the vertical direction. The sleeve structure is installed on the rear mold driving unit, and the rear mold forming cavity is formed on the sleeve structure. The front mold hot nozzle and the nozzle sleeve structure correspond to each other in the vertical direction, and the front mold forming cavity and the rear mold forming cavity form an injection cavity. The front mold drive unit is driven by the front mold cylinder, thereby driving the front mold hot nozzle to move away from or toward the nozzle sleeve structure, or the rear mold drive unit is driven by the output end of the rear mold cylinder, thereby driving the nozzle sleeve structure to move away from or toward the front mold hot nozzle.

2. The mold core retreat mechanism based on the micro-foaming process according to claim 1, characterized in that: The front mold includes a front mold fixing plate, a front mold drive unit fixing plate, and a front mold bottom plate. The front mold fixing plate, the front mold drive unit fixing plate and the front mold bottom plate are connected in sequence along the vertical direction to form an upper frame. The front mold drive unit is arranged in the upper frame and connected to the front mold hot nozzle, which is used to drive the front mold hot nozzle to move in the vertical direction, so that the front mold hot nozzle moves toward or away from the nozzle barrel structure in the vertical direction.

3. The mold core retreat mechanism based on the micro-foaming process according to claim 2, characterized in that: The front mold drive unit includes a front mold cylinder; the front mold drive unit fixing plate is a front mold cylinder fixing plate, the fixed end of the front mold cylinder is installed on the side wall of the cylinder fixing plate in the vertical direction, the output end of the front mold cylinder is vertically upward and connected to the hot runner fixing plate, the bottom of the hot runner fixing plate is fixedly connected to the hot runner plate in the vertical direction, the front mold A plate is fixedly mounted below the hot runner plate in the vertical direction, the front mold bottom plate is fixedly sleeved with the front mold A plate, the front mold hot nozzle is installed on the hot runner plate, and sleeved on the front mold A plate.

4. The mold core retreat mechanism based on the micro-foaming process according to claim 1, characterized in that: The rear mold includes a rear mold B plate and a rear mold driving unit. The sleeve structure is sleeved on the rear mold B plate and driven by the rear mold driving unit to move the sleeve structure toward or away from the front mold hot nozzle in a vertical direction.

5. The mold core retreat mechanism based on the micro-foaming process according to claim 4, characterized in that: The rear mold also includes a rear mold floating plate, square iron, a pad, a return pin, a push rod and a spring; The rear mold B plate is installed with the rear mold floating plate in the vertical direction, and the rear mold floating plate is installed with square iron in the vertical direction; the pad is connected with the square iron in the vertical direction, and the rear mold B plate, the rear mold floating plate, the square iron and the pad are collectively sleeved with return pins, and the return pins of the square iron and the pad are sleeved with springs, and the push rod is sequentially sleeved on the rear mold B plate, the rear mold floating plate, the square iron and the pad along the vertical direction; and the lower end of the spring is in contact with the rear mold driving unit; a sleeve structure is placed between the square iron and the pad.

6. The mold core retreat mechanism based on the micro-foaming process according to claim 5, characterized in that: A rear mold placement cavity is provided in the pad, a rear mold installation cavity is opened on the square iron, the rear mold placement cavity and the rear mold installation cavity form a combined cavity, and a rear mold driving unit is placed in the combined cavity.

7. The mold core retreat mechanism based on the micro-foaming process according to claim 6, characterized in that: The sleeve structure includes a sleeve and a sleeve needle. The upper end of the sleeve needle is vertically sleeved in the sleeve. The top of the rear mold B plate has a parting surface B corresponding to the parting surface A. The top of the sleeve extends out of the parting surface B and corresponds to the front mold hot nozzle. The rear mold driving unit drives the sleeve and the sleeve needle at the same time, so that the sleeve and the sleeve needle move toward or away from the front mold hot nozzle at the same time along the vertical direction.

8. The mold core retreat mechanism based on the micro-foaming process according to claim 7, characterized in that: The rear mold driving unit includes an upper ejector plate, an upper oblique shovel, a lower ejector plate, and a lower oblique shovel. The lower layer oblique shovel, lower layer ejector plate, upper layer oblique shovel, and upper layer ejector plate are arranged in sequence along the vertical direction, and the sleeve is sleeved on the upper layer ejector plate, and the sleeve needle is sleeved on the lower layer ejector plate. A bracket is installed on the rear mold, and a rear mold driving mechanism is provided on the bracket. The rear mold driving mechanism is used to simultaneously drive the upper layer oblique shovel and the lower layer oblique shovel, so that the sleeve and the sleeve needle move toward or away from the front mold hot nozzle at the same time along the vertical direction.

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