阅读说明：本技术 一种微应力模芯及包含所述微应力模芯的模具 (Micro-stress mold core and mold comprising same ) 是由 李代伟 李周才 曾新建 于 2020-06-16 设计创作，主要内容包括：本发明提供一种微应力模芯及包含所述微应力模芯的模具,属于模具结构领域。本发明微应力模芯包括模芯本体,所述模芯本体包括安装所述模芯本体的安装面、设置产品型腔的模腔面,及设置在所述安装面和模腔面外围的侧面,其中,所述安装面设有加强结构,所述安装面还设有模芯加热膨胀定位导向结构,所述加强结构和模芯加热膨胀定位导向结构均设有加热膨胀伸缩槽,所述侧面与安装板之间设有模芯膨胀间隙。本发明的有益效果为：最大程度减少模芯翘曲造成的产品变形。(The invention provides a micro-stress mold core and a mold comprising the same, and belongs to the field of mold structures. The micro-stress mold core comprises a mold core body, wherein the mold core body comprises a mounting surface for mounting the mold core body, a mold cavity surface for arranging a product cavity, and side surfaces arranged at the periphery of the mounting surface and the periphery of the mold cavity surface, the mounting surface is provided with a reinforcing structure, the mounting surface is also provided with a mold core heating expansion positioning guide structure, the reinforcing structure and the mold core heating expansion positioning guide structure are both provided with heating expansion telescopic grooves, and a mold core expansion gap is arranged between the side surfaces and the mounting plate. The invention has the beneficial effects that: and the product deformation caused by the warping of the mold core is reduced to the maximum extent.)

1. The micro-stress mold core is characterized in that: the die core comprises a die core body, wherein the die core body comprises an installation surface for installing the die core body, a die cavity surface for arranging a product die cavity, and side surfaces arranged on the periphery of the installation surface and the periphery of the die cavity surface, a reinforcing structure is arranged on the installation surface, a die core heating expansion positioning guide structure is further arranged on the installation surface, heating expansion telescopic grooves are formed in the reinforcing structure and the die core heating expansion positioning guide structure, and a die core expansion gap is formed between the side surfaces and the installation plate.

2. The micro-stress mold core of claim 1, wherein: the reinforcing structure comprises reinforcing ribs which are arranged on the periphery of the mounting surface and are integrally formed with the side surface, and reinforcing bones arranged in the reinforcing ribs.

3. The micro-stress mold core of claim 2, wherein: the die core heating expansion positioning guide structure comprises positioning ribs arranged at the transverse center and the longitudinal center of the mounting surface, and the positioning ribs protrude out of the surface of the reinforcing structure.

4. The micro-stress mold core of claim 3, wherein: the mold core heating expansion positioning guide structure further comprises a plurality of positioning columns arranged on the reinforcing ribs.

5. The microstress mandrel of any of claims 1-5, wherein: the mold core body is provided with more than 1 temperature zone, each temperature zone is provided with a set of heating device, a set of cooling device and a set of temperature measuring device for detecting the temperature of the mold cavity corresponding to the temperature zone, and the heating device and the cooling device in each temperature zone are independently controlled by a controller.

6. The micro-stress mold core of claim 5, wherein: the heating device is a heating pipe, the cooling device is a cooling pipeline with cooling water arranged inside, a water inlet of the cooling pipeline is arranged on one side of the mold core body, and a water outlet of the cooling pipeline is arranged on the other side, opposite to the water inlet, of the mold core body.

7. The micro-stress mold core of claim 6, wherein: the quantity of the heating pipes and the cooling pipelines is multiple, the heating pipes and the cooling pipelines are arranged at intervals, and the distances between the temperature measuring device and the heating pipes are equal to each other.

8. The micro-stress mold core of claim 6, wherein: the vertical distance between the temperature measuring device and the product cavity, the distance between the temperature measuring device and the cooling pipeline, and the distance between the temperature measuring device and the heating pipe are equal.

9. The micro-stress mold core of claim 6, wherein: the distance between the heating pipe and the installation surface of the mold core body is equal to the distance between the heating pipe and the cavity of the mold core body product.

10. A mold comprising the microstress core of any of claims 5-9, wherein: including thermal-insulated backup pad and mounting panel, wherein, one side of thermal-insulated backup pad is equipped with the mounting groove that corresponds with mold core thermal expansion location guide structure, the mold core thermal expansion location guide structure of microstress mold core is fixed in the mounting groove, the mounting panel is equipped with and holds the holding tank of mold core body and thermal-insulated backup pad, the mounting panel outside is equipped with inlet channel and outlet conduit who is linked together with cooling duct.

Technical Field

The invention relates to a die structure, in particular to a die for realizing die temperature balance.

Background

In an injection mold, a mold core is a precision part which is a key operation of a central part of the mold, and is a very important part in the mold, and the structure of the mold core directly determines the fineness degree of a product. The mold core has thermal expansion phenomenon in the heating process, if the mold core is subjected to thermal unbalance, the mold core can be subjected to thermal expansion buckling deformation, and for products needing precise processing, the deformation directly influences the precision of the products. However, no core has taken this into account at present. Therefore, a micro-stress mold core is urgently needed to solve the product deformation caused by the micro-strain of the mold core due to thermal expansion deformation.

In addition, only one set of heating pipe and cooling tube in current mold core carries out unified control by the controller, can't keep the mould temperature balance, and this kind of structure has following defect:

(1) the temperature of the mold cavity is fast and high at the position close to the heating pipe, and is slow and low at the position far from the heating pipe, so that the flowing of the injection molding liquid is not facilitated; in addition, the die core steel expands when heated, the higher the temperature is, the larger the shrinkage is after cooling, and the product deformation is easily caused by uneven shrinkage of the die;

(2) the cooling temperature on the surface of the product can not be controlled, the surface of the product in a low-temperature area is cooled firstly, and the surface of the product in a high-temperature area is cooled later, so that the appearance quality of the product can be influenced, and the warping deformation of the product can be easily caused.

In addition, prior art's cooling tube delivery port and water inlet all set up in mould one side, and cooling pipe is longer in the mould, are unfavorable for the cooling, and the difference in temperature of approach water pipeline and outlet conduit is great to the unbalance of mould temperature has been aggravated.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a micro-stress mold core and also provides a mold comprising the micro-stress mold core.

The micro-stress mold core comprises a mold core body, wherein the mold core body comprises a mounting surface for mounting the mold core body, a mold cavity surface for arranging a product cavity, and side surfaces arranged at the periphery of the mounting surface and the periphery of the mold cavity surface, the mounting surface is provided with a reinforcing structure, the mounting surface is also provided with a mold core heating expansion positioning guide structure, the reinforcing structure and the mold core heating expansion positioning guide structure are both provided with heating expansion telescopic grooves, and a mold core expansion gap is arranged between the side surfaces and the mounting plate.

The invention is further improved, and the reinforcing structure comprises a reinforcing rib which is arranged on the periphery of the mounting surface and is integrally formed with the side surface, and a reinforcing bone which is arranged in the reinforcing rib.

The invention is further improved, the die core heating expansion positioning guide structure comprises positioning ribs arranged at the transverse center and the longitudinal center of the mounting surface, and the positioning ribs are arranged to protrude out of the surface of the reinforcing structure.

The invention is further improved, and the die core heating expansion positioning guide structure further comprises a plurality of positioning columns arranged on the reinforcing ribs.

The invention is further improved, the mould core body is provided with more than 1 temperature zone, each temperature zone is provided with a set of heating device, a set of cooling device and a set of temperature measuring device for detecting the temperature of the mould cavity corresponding to the temperature zone, and the heating device and the cooling device in each temperature zone are independently controlled by a controller.

The invention is further improved, the heating device is a heating pipe, the cooling device is a cooling pipeline with cooling water arranged inside, a water inlet of the cooling pipeline is arranged on one side of the mold core body, and a water outlet of the cooling pipeline is arranged on the other side of the mold core body opposite to the water inlet.

The invention is further improved, the number of the heating pipes and the number of the cooling pipelines are multiple, the heating pipes and the cooling pipelines are arranged at intervals, and the distances between the temperature measuring device and the cooling pipelines are equal to each other.

The invention is further improved, and the vertical distance between the temperature measuring device and the product cavity, the distance between the temperature measuring device and the cooling pipeline, and the distance between the temperature measuring device and the heating pipe are equal.

In a further development of the invention, the distance of the heating tube from the mounting surface of the core body and the distance of the heating tube from the product cavity of the core body are equal.

The invention also provides a die containing the micro-stress die core, which comprises a heat insulation supporting plate and a mounting plate, wherein one side of the heat insulation supporting plate is provided with a mounting groove corresponding to the die core heating expansion positioning guide structure, the die core heating expansion positioning guide structure of the micro-stress die core is fixed in the mounting groove, the mounting plate is provided with a holding groove for holding the die core body and the heat insulation supporting plate, and the outer side of the mounting plate is provided with a water inlet pipeline and a water outlet pipeline which are communicated with a cooling pipeline.

Compared with the prior art, the invention has the beneficial effects that: the product deformation caused by the warping of the mold core is reduced to the maximum extent, and the precision machining of the product can be realized; through to the mould subregion and embedding temperature measuring device, every district controls the mould temperature alone, can guarantee that the mould temperature is balanced, does not receive the restriction of product size, shape, structure, wall thickness to avoid the phenomenon of the thermal expansion deformation that the mold core leads to because of being heated unbalance, also avoided the product because of the warp deformation that the unbalanced mold cavity temperature caused.

Drawings

FIG. 1 is a schematic view of the mold structure of the present invention;

FIG. 2 is a schematic diagram of a front core cavity face configuration;

FIG. 3 is a cross-sectional view of FIG. 2B-B;

FIG. 4 is an enlarged view of the portion C of FIG. 3;

FIGS. 5 and 6 are cross-sectional views of FIGS. 2A-A;

FIGS. 7 and 8 are schematic views of a front core mounting face;

FIG. 9 is a sectional view of another embodiment of the front core.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

As shown in fig. 1 to 6, as an embodiment of the present invention, the mold of the present invention includes a front mold core 3, a rear mold core 4, and a mold cavity 5 disposed between the front mold core 3 and the rear mold core 4, in this example, the front mold core 3 is provided with a heating device 16, a cooling device 15, and a temperature sensor 17 for detecting the temperature of the temperature zone corresponding to the mold cavity, in this example, the front mold core is provided for 1 to 2, that is, one mold is provided with two front mold cores 3.

As shown in fig. 3-5 and 7, the mold core 3 of the present invention includes a mold core body 301, the mold core body 301 includes a mounting surface 3012 for mounting the mold core body 301, a cavity surface 3011 for setting a product cavity for injection molding a product 19, and a side surface 3013 disposed at the periphery of the mounting surface 3012 and the cavity surface 3011, wherein the mounting surface 3012 is provided with a reinforcing structure, the mounting surface 3012 is further provided with a mold core heating and expanding positioning guide structure, the reinforcing structure and the mold core heating and expanding positioning guide structure are both provided with a heating and expanding telescopic slot 305, and a mold core expansion gap d is provided between the side surface 3012 and a mounting plate (in this example, a front mold core, the mounting plate is an a plate 7). The width of the mold core expansion gap d of the embodiment is 0.01mm, the width of the mold core expansion gap d is calculated according to the expansion coefficient of the front mold core 3 material and the required mold temperature, and the expansion gaps of different mold core materials are different. The core of the present embodiment is preferably made of steel with rapid heat conduction, high corrosion resistance, high toughness and tensile properties, so as to minimize the warpage of the die steel.

If the thermal expansion groove 305 and the core expansion gap d are not provided, the installation is limited, and when the front core 3 expands due to heat, the front core 3 is arched toward the product cavity, thereby affecting the appearance of the product 19 in the product cavity 5. The micro-stress mold core of the embodiment can well avoid the micro-strain phenomenon of the front mold core 3.

As shown in fig. 7, the reinforcing structure of this embodiment includes reinforcing ribs 304 integrally formed with the side surface and disposed around the mounting surface, and reinforcing ribs 302 disposed inside the reinforcing ribs 304, wherein the reinforcing ribs 302 are disposed in a criss-cross manner to connect the reinforcing ribs 304 at both ends, so that the rigidity of the steel material can be improved, and the core body 301 can be made as thin as possible, thereby reducing the absorption and conduction of energy of the core body 301, increasing the rate of heating the mold temperature, and making the temperature more controllable, thereby avoiding the situation that the temperature of the cavity is increased greatly by the energy accumulated in the core after the heating is stopped. The mold core body 301 of the embodiment realizes a lightweight design on the premise that rigidity is not affected. The raw material is saved.

The mold core heating expansion positioning guide structure comprises positioning ribs 303 arranged at the transverse center and the longitudinal center of the mounting surface 3012, so that the central position of the whole front mold core 3 is fixed, the phenomenon that the center is deviated due to shrinkage of the mold core body 301 is avoided, and the positioning ribs 303 protrude out of the surface of the reinforcing structure. The front mold core 3 is fixed as a fixing structure.

The mold core heating expansion positioning guide structure of this example still includes and sets up 4 reference columns 306 on the strengthening rib 304, reference column 306 sets up on four angles of mold core body 301, combines location muscle 303 to it is spacing to middle part and four angles of mold core body 301, preferred, location bone 306, location muscle 304 and the flexible groove 305 of heating expansion use the location muscle 303 to set up as center pin axial symmetry, more do benefit to the shrink balance after the thermal expansion of mold core body 301. The phenomenon that the surface of the product 19 is deformed due to the micro deformation of the mold core caused by the unbalanced shrinkage after heating and thermal expansion is avoided.

As shown in fig. 2, 7 and 8, since the higher the temperature of the core body 301, the greater the shrinkage, therefore, the unbalanced heating of the core body 301 also causes a micro strain of the core body 301, therefore, in order to keep the temperature balance between the mold core body 301 and the mold cavity of this embodiment, each front mold core 3 of this embodiment is provided with 2 temperature zones, 4 temperature zones are provided for 2 front mold cores 3, each temperature zone is provided with a set of heating device 1601 and cooling device 15 and a temperature sensor 17, the heating device 16 and the cooling device 15 in each temperature zone are controlled by the controller, the number of the rear mold cores 4 of this embodiment is also 2, each rear mold core 4 is provided with 2 cooling zones (not shown in the figure, the installation manner of the cooling device is the same as that of the front mold core 3), each cooling zone is provided with a set of cooling device 15, and the cooling device in each cooling zone 15 is controlled by the controller.

The heating device 16 in this example is a heating pipe, and the cooling device 15 is a cooling pipe with a cooling medium therein. The cooling medium in this example may be water or another liquid medium that absorbs heat.

As shown in fig. 1-6, the heating device 16 of this embodiment is disposed on the front mold core, so that the mold is further provided with a heat insulation support plate 5 on the top surface of the front mold core 3 to prevent heat loss. One side of thermal-insulated backup pad 5 is equipped with the mounting groove that corresponds with mold core thermal expansion location guide structure, the mold core thermal expansion location guide structure of microstress mold core is fixed in the mounting groove, A board 7 is equipped with and holds mold core body 301 and thermal-insulated backup pad 5's holding tank, thermal-insulated backup pad 5 is fixed in A board 7 bottom surface, cooling duct 15's water inlet 1501 sets up the one side at the mould, cooling duct 15's delivery port 1502 sets up the opposite side at the mould. The water inlet 1501 and the water outlet are both arranged on the A plate 7 and are communicated with a cooling pipeline in the front mold core 3. The cooling water enters from one side of the die and flows out from the other side, so that the time of the cooling water staying in the cooling pipeline is greatly shortened, more cooling water passes through the cooling pipeline in unit time, and the cooling efficiency is better. All the cooling pipelines are arranged in parallel in the mold core, and the water flow reaching the vicinity of the mold cavity is basically consistent, so that the mold temperature balance is favorably kept.

The top surface of the A plate 7 is provided with a runner plate 9, and the top surface of the runner plate 9 is a panel 10. The rear mould core 4 of the embodiment is fixed on a B plate 8, two square irons 11 are arranged on two sides between a bottom plate 14 and the B plate 8, an ejector pin bottom plate 13 is fixed on the bottom plate between the two square irons, an ejector pin panel 12 is arranged on the ejector pin bottom plate 13, and two ejector pins penetrate through the B plate 8 and are connected with a mould cavity.

Of course, the temperature zone of this embodiment may be set on the rear mold core 4 to realize the heating and cooling functions of the front mold core 3 and the rear mold core 4 at the same time, or the temperature zone may be set on the rear mold core 4 and the cooling zone may be set on the front mold core 3, so that the heating device on the rear mold core 4 heats the mold cavity 5 and the cooling device on the front and rear mold cores cools the product. In this case, the heat insulating support plate is disposed on the side where the heating means is provided.

A plurality of temperature areas are adopted for respectively heating or cooling, each temperature area and each cooling area are independently controlled, and an independent temperature sensor 17 is arranged, so that the temperature of the die cavity can be accurately controlled, the temperature difference can be controlled within 2 ℃, the micro-stress of the die core body 301 is ensured, the thermal expansion deformation is prevented, the die temperature balance of the die cavity is favorably kept, and the warping deformation of the product 19 caused by unbalanced heating and cooling is prevented.

As shown in fig. 9, the micro-stress mold core of this embodiment is particularly suitable for processing high-precision products, and as an embodiment, if the product is in a flat arc shape, the micro-stress mold core of this embodiment can divide the front mold core 3 and the rear mold core into 8 regions (the vertical line is the boundary of each region) according to the shape of the mold cavity, so as to control the temperature of each temperature region independently, thereby avoiding the problems that the cooling pipe and the heating pipe are horizontally arranged in the prior art, the distance from the mold cavity 5 is too large, the mold temperature difference of the product is too large, the mold cavity temperatures are different, the molten state liquid fluidity is different during injection molding, the shear rate is different, and the quality of the product cannot be guaranteed; the different steps of cooling cause warping and deformation of the product. The invention is especially suitable for the die cavity with a three-dimensional complex shape, and the subareas are set according to the shape of the product, thereby ensuring the temperature difference of each area of the product. The scheme of the invention is not limited by the size, shape, structure and wall thickness of the product. The processing method can process thin-wall products with the thickness of more than or equal to 0.5mm, and can not cause the warping deformation of the products.

The mounting surface 3012 of the front core 3 of this embodiment can also be processed into a non-planar structure according to the shape of the product, as long as the surface of the reinforcing structure is ensured to be horizontally contacted with the surface of the heat insulation support plate 6. Of course, the surface of the heat insulation support plate 6 in this embodiment can also be matched with the surface of the front mold core 3012, so that the heat insulation effect is better.

As shown in fig. 5 to 8, in this example, the number of the heating pipes and the cooling pipes in each temperature zone is plural, and the heating pipes and the cooling pipes are arranged at intervals. Thereby facilitating control of the balance of temperature differences.

The distances between the temperature sensor 17, the cooling pipeline 15 and the heating pipe 16 are equal, and preferably form an equilateral triangle. The distance between the temperature sensor 17 and the mold cavity, the distance between the temperature sensor 17 and the cooling pipeline 15, and the distance between the temperature sensor 17 and the heating pipe are equal. Thereby making the mold temperature measured by the temperature sensor 17 more accurate. The design reason for the multipoint distance equality is that: the front mold core 3 is heated or cooled in the heating or cooling process (steel material) to have energy-gathering and heat-conducting time, so that the sensor 17 is arranged at the average value of the distances between the cooling pipeline 15 and the heating pipe 16 and the surface of the mold cavity, and the heating, cooling and mold cavity surface (namely the surface temperature of a product) test results are more accurate.

The distance x between the heating pipe and the top surface of the front mold core is equal to the distance y between the heating pipe and the cavity surface of the front mold core. The measurement is more accurate, and the distance between the cooling pipeline in the front mold core of the embodiment and the top surface of the front mold core is equal to the distance between the cooling pipeline in the front mold core and the cavity surface of the front mold core.

Through the subregion and embedding temperature measuring device to the mould, the control mold temperature is alone controlled in every district, effectively guarantees mould temperature balance, does not receive the restriction of product size, shape, structure, wall thickness. Can process products with various shapes and can ensure the quality and the appearance quality of the products.

As shown in fig. 3 and 4, in the plate a design of this example, the thermal expansion phenomenon of the steel material of the front core 3 is sufficiently considered, and therefore, a core expansion gap d of 0.01mm exists between the outer periphery of the front core and the plate a, but since the front core 3 of this example is provided in two-in-one arrangement and the runners are provided between the two front cores 3, in order to avoid the branch runners between the runners and the gates 3 from interfering with the micro-strain of the front core 3, in this example, a bridging insert 18 is provided on the plate a 7, the bridging insert 18 rides over the core expansion gap d of the plate a 7 and the front core 3, the runners and the branch runners of the gates 3 are provided over the bridging insert 18, and the bridging insert 18 is in clearance fit with the front core 3, so that the thermal expansion and contraction of the front core 3 are not interfered. In addition, the phenomenon that the molten liquid flows into the mold core expansion gap d to block the mold core expansion gap d can be effectively avoided.

The above-described embodiments are intended to be illustrative, and not restrictive, of the invention, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.