WO2015189912A1

WO2015189912A1 - Gas releasing structure in die and die provided with said structure

Info

Publication number: WO2015189912A1
Application number: PCT/JP2014/065339
Authority: WO
Inventors: 齋藤輝彦
Original assignee: ケンモールドサービス株式会社
Priority date: 2014-06-10
Filing date: 2014-06-10
Publication date: 2015-12-17
Also published as: JPWO2015189912A1; JP5808503B1

Abstract

This gas releasing structure in a die is provided with: a sliding member that receives the pressing force of an elastic body and has an upper side having an inverted trapezoidal cross section and a lower side having a rectangular solid cross section; and a sliding member receiving body that receives the sliding body in a manner able to slide in a direction (R). While a fluid is a gas, same passes through gaps (S1, S2, S3) as flow paths and is released to the outside through gas release openings interconnecting with same, and when the fluid has transitioned to being a fused material, the sliding member moves, sealing gaps (S2, S3) and preventing any further transit of the fused material.

Description

Gas release structure in mold and mold having the structure

The present invention relates to a molten material filling space (hereinafter referred to as “cavity”) of a mold used for injection molding various plastics, ceramics, rubber-based materials, glass-based materials, etc., or die-casting metals or alloys. The internal appearance of the molded product is improved by reducing the adverse effects of the gas generated from the molten material and the residual air in the space (hereinafter also referred to as “gas”) on the molded product. With regard to the gas release structure in the mold for greatly reducing the generation and the mold having the structure, in particular, the gas of gas is surely released to the outside and the outflow of the molten material to the outside is surely prevented. The structure can be mounted in a three-dimensional manner perpendicular to the bottom surface of the cavity, and the tab formed on the gas discharge structure can be efficiently processed at the time of mold release. Mold about having a gas release structure and the structure of the mold that can.

Fixed and movable in injection molding using various plastics (synthetic resins), ceramics, rubber-based materials, glass-based materials, liquid crystals, etc., and die-casting using various metals such as aluminum, zinc, tin, and copper. It is molded by a mold consisting of a combination of A molten material such as plastic or metal is pressurized and filled into the cavity, and then a product having a desired shape and structure is obtained through a predetermined cooling process. When plastics, ceramics, rubber-based materials, glass-based materials, etc., which are raw materials, or metal-based materials are melted to a state suitable for molding, gas corresponding to each component is generally generated. The type and amount of generated gas vary depending on the heating temperature, the type of material, the added auxiliary material, and the like, and also vary depending on the volume of the cavity.

The mold cavity is precision finished to improve the properties and appearance of the product surface, and the joint surface of the fixed / movable mold is processed so as to be intimately sealed. Furthermore, in order to improve the airtightness of the joint surface of the fixed / movable mold, an elastic packing or the like may be interposed. In the cavity that maintains such high airtightness, there are gas components composed of gases generated from the molten material and residual air in each part of the mold as described above. The presence of these gases tends to lose escape during compression due to the press-fitting of the melt, impedes the flow expansion of the molten material into the cavity, and tends to cause molding defects such as short shots and surface asymmetry. On the other hand, when there is a gap that allows the outflow of the gas component freely, the molten material enters, and burrs and cast holes (unevenness) are generated on the surface of the molded product, thereby degrading the quality of the product.

In order to eliminate the adverse effects of the gases confined in the cavity as described above, the inventor disclosed in Patent Document 1 that the tip of the melt-molding material that flows in the mold without using an external control means. A gas discharge structure inside a filling space of a mold that automatically operates by a pressing force and a mold having the gas discharge structure are proposed.

The gas discharge structure proposed here is a sliding member that receives a pressing force by the elastic body 14 from the opposite surface side, and communicates with the bottomed hole 12 formed in the flow direction R of the molten material and the bottomed hole. And a sliding member 10 having at least one side opening 13 that opens in a direction intersecting the flow direction of the molten material, and the slide member is slidably received in a direction parallel to the flow direction of the molten material. In the initial state where the molten material is not subjected to the flow pressure, the sliding member communicates with the side opening 13 of the sliding member, and then the sliding member slides in a direction against the elastic body by the flow front end of the molten material. A gas discharge structure in a mold comprising a sliding member receiver 20 having a gas discharge port 21 that is closed when moved, and a filling space formed by a fixed mold and a movable mold, or Connected to the filling space And it is configured so as to be mounted near the middle or end of the molten material flow passage.

The gas discharge structure proposed in Patent Document 1 is based on the premise that the sliding member moves (actuates) by the pressing force of the tip of the molten material flow. When injection molding (for example, nylon, LCP, etc. used in connector products), there is a case where the sliding member does not move smoothly due to the weak pressing force at the tip of the molten material flow. In the state in which the gas does not move, the side opening of the sliding member communicates with the gas discharge port formed in the sliding member receptor, and the molten material flows out of the communicating hole together with the gases. Problem has occurred.

Therefore, in order to solve the above problem, the inventor in Patent Document 2 moves (actuates) the sliding member smoothly by the pressing force of the tip of the molten material flow and reliably prevents the molten material from flowing out. In order to achieve this, a structure for increasing the portion where the tip of the molten material flow comes into contact with each other and a gas discharge structure for expanding the volume of the space into which the molten material flows are proposed. The gas discharge structure proposed here is the same as the structure proposed in the above-mentioned prior art document 1, the gap S1 into which the flow front end of the molten material enters the front surface 16 of the sliding member of the sliding member receptor, the sliding member Inclined surface SF1 of the sliding surface on the bottom surface 17, the size of the bottomed hole 12 of the sliding member, a configuration in which the volume is expanded, and a curved or linear inclination to an arbitrary section from the upper end to the gas discharge port A configuration in which the surfaces SF2, SF3, etc. are formed is employed.

In any of the gas discharge structures disclosed in Patent Documents 1 and 2, the sliding member communicates with the bottomed hole, communicates with the bottomed hole, and communicates with the gas discharge port formed in the sliding member acceptor. The side opening is formed, and the flow passage of gases is made into a bottomed hole, side opening, and gas discharge port, and the outflow of molten material to the outside is blocked by blocking the side opening and gas discharge port. Is. In short, the structures disclosed in these documents prevent the outflow of the molten material to the outside by closing the hole (side opening) and the hole (gas discharge port). In addition, high precision is required for forming the bottomed hole, the side surface opening, and the inclined surface for the sliding member, and both of the production of the gas discharge structure disclosed in Patent Documents 1 and 2 are both time consuming and expensive. Needed cost.

Also, depending on the molded product, when gases and molten materials were concentrated near the center of the bottom of the cavity, dummy pins were attached to the bottom of the cavity and gas was released from the joint of the cavity, but the efficiency was poor. Moreover, even if the gas release structure described in Patent Documents 1 and 2 is mounted three-dimensionally orthogonal to the bottom surface of the cavity, the molten material that has entered the upper end of the sliding member becomes a tab called surplus, Processing was a problem.

Patent Document 3 is a document disclosing an inclined slide mechanism for releasing an undercut portion of a resin molded product. Patent Document 3 is a mold for molding a resin molded product, and includes a cavity constituting the mold, a core movable relative to the cavity, and an ejector provided on the back of the core and movable relative to the core. A plate, an inclined core portion provided on one end side for forming an undercut portion of the resin molded product, and an inclined pin connected to the inclined core and inserted through the core; the other end side of the inclined pin In the mold apparatus for resin molding having an inclined slide provided with a slide unit that is slidable with respect to the ejector plate, the inclined slide is disposed on the core side when the cavity and the core are separated from each other. Providing a protrusion amount regulating means for guiding the inclined pin so that the amount of the inclined core portion protruding from the core is smaller than the distance to advance. Discloses a resin molding die apparatus are. An object of the invention disclosed herein is to provide a mold apparatus for resin molding that can reliably release an undercut portion of a resin molded product and that does not damage the mold during mold clamping. It is not intended to mount a gas discharge structure on a mold, and is not intended for releasing a tab formed by mounting the gas discharge structure, and does not relate to tab processing.

Japanese Patent No. 4455676

International Publication WO2013 / 140580

Japanese Patent Laid-Open No. 10-264217

As a result of further experimentation and research and development on the gas discharge structure to solve the above-described problems, the inventor did not form a bottomed hole and a side opening on the sliding member of the gas discharge structure. It is possible to reliably prevent the molten material from flowing out by close engagement, and to ensure the release of the tab formed in the gas release structure during molding, orthogonal to the bottom of the cavity As a result, a gas release structure that can be mounted three-dimensionally has been developed.

An object of the present invention is to provide a gas discharge structure capable of surely preventing outflow of a molten material to the outside with a simple structure and greatly reducing manufacturing costs by close contact between the surfaces, and a gas discharge structure It is an object of the present invention to provide a gas discharge structure with an inclined slide mechanism that can efficiently perform the release of the tabs formed on the housing and can be three-dimensionally mounted perpendicular to the bottom surface of the cavity.

In addition, the metal mold | die used as the object of this invention is not limited to the metal mold | die for injection molding of various plastics (synthetic resin), For example, a ceramic, rubber-type material which press-molds a molten material in a cavity, and molds it. Included are molding molds made of glass-based materials, liquid crystals and the like, and die casting molds made of various metals such as aluminum, zinc, tin and copper.

The invention according to claim 1 is a sliding member that receives a pressing force by the elastic body 14 from the opposite surface side, the upper side is an inverted trapezoidal cross section 10a, and the lower side where the elastic body is mounted on the bottom surface is a rectangular parallelepiped. A first gap S1 for receiving a fluid from the molten material filling space on the upper surface, and communicating with the first gap S1 on both side surfaces from both ends of the upper surface to the bottom of the gas discharge port. Then, the sliding member 10 that secures the second gap S2 and the third gap S3 to be gas flow paths and forms the first inclined surface SF11 and the second inclined surface SF12, and the sliding member The molten material is slidably received in the flow direction R of the molten material, the first gap S1 is secured on the upper surface portion, and the first inclined surface SF11 and the second inclined surface SF12 corresponding to the first inclined surface SF12 are provided on both inner side surfaces. The inclined surface SF21 and the fourth inclined surface SF22 are formed, A sliding member receiver 20 having a gas discharge port 23 that is closed when the moving member moves in the direction D against the elastic body by the flow front end of the molten material to the bottom position BP of the gas discharge port. A gas discharge structure that is mounted in the middle or near the end of a molten material filling space formed by a fixed mold and a movable mold or a molten material flow path connected to the filling space, and flows from the molten material filling space While the body is a gas, the first gap S1, the second gap S2, and the third gap S3 are allowed to pass as flow passages, and are discharged to the outside through the gas discharge ports 23 that communicate with them. Is moved from the gas to the molten material, the sliding member 10 moves to the bottom position BP of the gas discharge port to close the gas discharge port 23, and the first inclined surface SF11, the third inclined surface SF21 and the first inclined surface SF21. 2 inclined surfaces F12 and the fourth inclined surface SF22 are closely engaged with each other and are in close contact with each other so that the second gap S2 and the third gap S3 are hermetically sealed to prevent subsequent passage of the molten material. It is the inside gas discharge structure.

The invention according to claim 2 is the one in which the gas discharge structure according to claim 1 is mounted orthogonally below the vicinity of the center of the bottom surface of the molten material filling space C, and incorporates an inclined slide mechanism. The gas discharge structure according to claim 1, wherein the sliding member receiver is mounted perpendicularly below a central portion of the bottom surface of the filling space C and provided with an inclined slide mechanism. A flow path 31 for receiving a fluid from an opening CH opened near the center is formed to protrude from the upper surface, and the first gap S1 communicating with the flow path 31 is secured at the lower portion of the upper surface to slide. The member 10 is received, and an inclined shaft 32 having inclined portions at the lower portion 30b and the back surface portion 30c of the sliding member receiving portion 30a on the surface portion of the sliding member receiver is formed, and the inclined shaft is raised at the time of mold release. Slide towards direction U The tab formed by the molten material that has entered the upper end of the sliding member when the sliding member 10 moves to the bottom position BP of the gas discharge port 33 while moving up to the horizontal direction H while pushing up the molded product by the operation. It is a gas release structure in a mold configured to escape from T.

The invention described in claim 3 is that the elastic body 14 pressing the sliding member in the gas discharge structure in the mold according to claim 1 against the opposing surface is a coil spring, a leaf spring, or a rubber system. It is composed of one or more combinations selected from an elastic body and a fluid compression actuator. The invention according to claim 4 is characterized in that the gas discharge structure according to any one of claims 1 and 3 can be fitted and mounted in a mounting recess formed in a required portion in the mold.

According to a fifth aspect of the present invention, there is provided a molten material filling space in which the gas discharge structure in the mold according to any of the first, third, and fourth aspects is formed by a fixed mold and a movable mold, or the filling space. In the middle of the molten material flow path leading to the end of the molten material flow path, it is a die that is integrally arranged in advance near the end.

The gas release structure in the mold according to the present invention is a mold essential for injection molding, die casting molding, etc., in the middle of the molten material flow path located on the side far from the gate or in the vicinity of the end of the molten material flow Is attached to a portion that receives a pressing force. In addition, the flow analysis using a computer can be utilized for determination of a specific attachment site | part.

In the gas discharge structure in the mold according to claim 1, the clearance S1 is secured on the upper surface, and the clearances S2 and S3 that communicate with the clearance S1 and serve as gas flow paths are secured on both side surfaces to form the inclined surface SF11. 12 is formed, and a clearance S1 is secured on the upper surface portion, and inclined surfaces SF21 and SF22 corresponding to both inclined surfaces of the sliding member are formed on both inner side surfaces. It has a simple structure including a sliding member receiver having a gas discharge port 23 that is closed when it moves to the bottom position of the outlet, and can be easily manufactured without high cost.

In the gas discharge structure according to claim 1, the gaps S1, S2, and S3 communicate with each other until the sliding member is pressed downward by the tip of the flowing molten material flow, The gas can be released freely without any resistance to the outside, and then the filling of the molten material into the cavity proceeds, and when the sliding member is pressed by the molten material flow tip and moves to the bottom position of the gas discharge port, Inclined surfaces SF11 and 21, and SF12 and 22 are closely engaged with each other to close the gaps S2 and S3, and the gas discharge port is closed, so that the outflow of the molten material flow is reliably prevented. In addition, since the sliding member secures the first gap S1 for receiving the fluid on the upper surface contacting the tip of the flowing molten material flow, the sliding member is surely moved downward by the tip of the molten material ( The molten material can be reliably prevented from flowing out.

Such a gas discharge structure in the mold according to claim 1 can be prepared in advance as a standard product having a typical outer dimension. A recess as a mounting portion that can receive this standard product is formed in a required portion at the time of mold production, and can be fitted and mounted by screwing or the like afterwards. The manufacturing process of the mold body may be performed separately according to a conventional method except for the formation of the mounting recess. The gas discharge structure according to the present invention configured in the standard form as described above can be configured to be detachable from the mounting recess formed in this way. Therefore, the gas discharge structure is prepared in advance as a single unit and can be mounted on a mold having a mounting recess, so that work efficiency can be improved and material costs and manufacturing man-hours can be reduced. If a gas discharge structure is unnecessary depending on the type and characteristics of the molten material to be molded, a dummy (blind member) formed with the same outer shape may be fitted and fixed.

By adopting such a detachable configuration, the gas release structure according to the present invention can be removed from the old mold at the time of manufacturing a new mold by changing the model of the product, etc. It can be attached and reused, and it can save resources, labor, and costs, so it has a great economic effect. For molds that do not need to be taken into account, and that are expected to continue to be used for a long time without any changes, a mold that incorporates a gas discharge structure with the same structure from the beginning is manufactured integrally. can do.

According to a second aspect of the present invention, there is provided a gas release structure in the mold in which the gas release structure according to the first aspect is mounted orthogonally below the vicinity of the center of the bottom surface of the molten material filling space C to release the tab. The sliding member receiver 30 is formed with a flow path 31 for receiving a fluid from the opening CH of the molten material filling space C on the upper surface, and the flow path at the lower portion on the upper surface. An inclined shaft that secures the gap S1 communicating with 31 and receives the sliding member 10 therein, and has the lower portion 30b and the back portion 30c of the sliding member receiving portion 30a of the surface portion of the sliding member receiver as inclined surfaces. 32. Therefore, the tab T formed by the molten material that has entered the upper end portion of the sliding member can be efficiently released, and the three-dimensional mounting of the gas release structure orthogonal to the bottom surface of the cavity is possible. According to the present invention configured as described above, the occurrence of product defects due to the occurrence of short shots, cast holes, burrs, and the like on the molded product is greatly reduced, which can contribute to productivity improvement.

It is a figure for demonstrating Example 1 of the gas discharge | release structure in the metal mold | die which concerns on this invention, (A) is a top view of the gas discharge structure in an initial state, (B) shows the gas discharge state in an initial state. Front view, (C) is a central cross-sectional view of FIG. (B), (D) is a front view showing a state in which the sliding member moves and the molten material is filled in the upper portion of the sliding member, and (E) is a diagram (D). FIG. It is a figure for demonstrating Example 2 of the gas discharge | release structure in the metal mold | die which concerns on this invention, (A) is a top view of the gas discharge structure in an initial state, (B) shows the gas discharge state in an initial state. A front view and (C) are center sectional views of a figure (B). It is a figure for demonstrating Example 2 which concerns on this invention, (A) is a front view which shows the state which mounted | wore the gas discharge structure to the cavity, (B) is a center sectional drawing of a figure (A). It is a figure for demonstrating Example 2 which concerns on this invention, (A) is a front view which shows the state which the molten raw material from a cavity entered the flow path and the sliding member upper end part, (B) is a figure (A (C) is a figure for demonstrating the operation | movement function of an inclination slide mechanism. It is a figure for demonstrating the attachment site | part and tab of the gas discharge | release structure of Example 2 which concern on this invention. It is a conceptual diagram which shows the example (A), (B), (C), (D) of the attachment site | part of the gas discharge | release structure of Example 1 which concerns on this invention.

DESCRIPTION OF SYMBOLS 10 Sliding member 10a Reverse trapezoid cross-section sliding member 10b Rectangular parallelepiped sliding member 14 Elastic body (compression spring)
20 Sliding member receiver 23 Gas discharge port 30 Sliding member receiver 30a Sliding member receiving portion 30b of sliding member receiver Lower portion 30c of sliding member receiving portion Back surface portion 31 of sliding member receiver Fluid receiving Flow path 32 Inclined shaft S1 First clearance S2 Second clearance S3 Third clearance SF11 First inclined surface SF12 Second inclined surface SF21 Third inclined surface SF22 Fourth inclined surface RF Filled molten material BP Gas Bottom position C of discharge port Molten material filling space (cavity)
CH Cavity opening T Tab A Gas release structure G Gas flow direction R Melt material flow direction D Direction of movement of sliding member (direction against elastic body)
U Direction of upward movement of gas discharge structure (tilt shaft) H Direction of horizontal movement of gas discharge structure (tilt shaft)

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of a gas discharge structure (hereinafter simply referred to as “gas discharge structure”) in a mold according to the present invention will be disclosed with reference to the accompanying drawings. FIG. 1 is a diagram for explaining Example 1 of a gas discharge structure, and is a plan view (A) of a gas discharge structure in an initial state, a front view (B) showing a gas discharge state in an initial state, and a central sectional view ( C) A front view (D) and a central sectional view (E) showing a state in which the sliding member has moved and the molten material is filled in the upper portion of the sliding member.

Here, the initial state means that the sliding member 10 does not move downward and the gas from the cavity passes through the first, second, and third gaps S1, S2, and S3 and the gas discharge port 23 as a flow passage and is externally passed. The state in which the molten material is filled in the upper part of the sliding member is a state in which the sliding member moves downward and the gas flow passage is closed. In addition, the part shown with the chain line in the figure represents hiding inside. In drawing drawing, since the gas discharge structure is a vertical shape, the sliding direction of the sliding member is expressed as a vertical direction as indicated by an arrow D, but the gas discharge structure according to the present invention is a horizontal type or a diagonal type. Is the horizontal or diagonal direction. In addition, expressions such as “upper”, “lower”, “upper surface”, and “lower surface” are merely representations of the state illustrated in the accompanying drawings, and are not related to the posture or arrangement in the actual use state. . The same applies to the following description.

The gas discharge structure according to the first embodiment of the present invention includes a sliding member 10 and a sliding member receiver 20 as shown in FIG. The sliding member 10 receives a pressing force from the opposing surface side by the elastic body 14, and the upper side forms an inverted trapezoidal cross section 10a, and the lower side forms a rectangular parallelepiped shape 10b. An elastic body 14 is disposed on the bottom surface of the rectangular parallelepiped portion 10b. The rectangular parallelepiped portion 10b has a function of guiding a reliable sliding operation (elevating motion) of the sliding member.

A first gap S1 (hereinafter also simply referred to as “gap S1”) formed with a step from the upper surface of the sliding member receiver 20 is secured on the upper surface of the sliding member. The gap S1 has the same size as the upper surface, and receives the gas flowing from the cavity C (from the upper side of the drawing) and the flow front of the molten material as indicated by arrows G and R. The second gap S2 and the third gap S3 (hereinafter simply referred to as “gap S2”, “hereinafter referred to as“ gap S2 ”,“ The first inclined surface SF11 and the second inclined surface SF12 (hereinafter also simply referred to as “inclined surface SF11” and “inclined surface SF12”) are formed by securing the clearance S3 ”.

The sliding member receiver 20 receives the sliding member 10 so as to be slidable in the flow direction R of the molten material while ensuring a gap S1 on the upper surface portion. Third and fourth inclined surfaces SF21 and SF22 (hereinafter also simply referred to as “inclined surface SF21” and “inclined surface SF22”) engaged with both inner side surfaces facing the inclined surfaces SF11 and SF12 of the sliding member, respectively. .) And gas discharge ports 23 are formed on both sides of the lower end portions of the inclined surfaces SF21 and SF22. The gas discharge port 23 is closed when the sliding member moves to the bottom position BP of the gas discharge port in the direction D against the elastic body by the flow front end of the molten material. In the gas discharge structure, the sliding member and the sliding member receiver can be divided at arbitrary portions, and one can be divided and attached to the fixed mold side and the other to the movable mold side. The outlet can be formed as a groove-like body not by drilling but by cutting.

Next, the operation and function of the gas release structure according to the first embodiment of the present invention will be described. The sliding member 10 is positioned upward as shown in FIGS. (B) and (C) by the pressing force of the elastic body 14 in the initial state where no external force is applied, and the gaps S1, S2, S3 and the gas discharge port 23 is in communication. The gas flow from the cavity is received in the gap S1, and the gas passes through both the gaps S2 and S3 from the gap S1 and is discharged from the gas discharge port 23 communicating with these gaps to the outside of the cavity. As a result, the flow of the molten material is hindered by the presence of gases and the occurrence of molding defects such as short shots and product deterioration such as burning, which tend to occur when the end of the cavity is not sufficiently reached, and the occurrence of cast holes, is reduced.

Thereafter, when the fluid from the cavity moves from the gas to the molten material, the flow front end of the molten material enters the gap S1, and the sliding member 10 is inclined by the pressing force of the front end of the molten material SF11, 12, 21, It moves down along 22 in the direction D against the elastic body. As the sliding member moves, the inclined surfaces SF11 and SF21, SF12 and SF22 are in close contact with each other, and the gaps S2 and S3 are sealed, as shown in FIGS. When moving to the bottom position BP of the discharge port, the communication with the gaps S2, 3 is blocked and the gas discharge port 23 is closed. By these operations, the outflow of the molten material to the outside is surely prevented, and good molding results can be expected. The filled molten material RF that has entered the gap S1 can be configured to be pushed out by an ejector pin (not shown) separately provided.

The width of the gap S1 is preferably about 1/1000 to 7/100, more preferably about 2/1000 to 5/100, depending on the size of the gas release structure. The inclination angle of the inclined surface is preferably about 0.5 to 2 degrees, more preferably about 0.1 to 1 degree. The gap interval and the gradient amount of the inclined surface are determined in accordance with the type and properties of the molten material such as resin.

The gas release structure according to the first embodiment of the present invention is mounted on the same plane in the middle or near the end of the molten material flow path connected to the cavity or cavity. FIG. 6 schematically illustrates an arrangement example of the gas discharge structure A according to the first embodiment inside the mold. In the figure, the solid line arrow indicates the flow direction of the molten material, and the broken line arrow indicates the gas flow. It represents the direction. FIG. (A) is an example in which a molten material is press-fitted from a left end gate which is a single gate. The flow direction of the molten material is also a single simplest configuration example, and shows an example in which the gas discharge structure A is disposed on the end side in the flow direction of the molten material. FIG. (B) is an embodiment in which the molten material flows by bifurcating in the left and right directions with a single gate, and the gas discharge structures A are arranged in the vicinity of the respective molten material flow ends. FIG. 6C is an example in which a large molded article is mainly molded by a multi-point (2) gate. One gas discharge structure A is provided near the junction of molten materials flowing from the left and right gates 1 and 2. An example in which is provided is shown.

FIG. (D) shows an embodiment in which the molten material flow path is divided into two halves from the single gate to the branch path, and the cavity is filled from two directions. In this example, two gas discharge structures A are disposed at the flow direction tip of the molten material at the bent portion of the molten material flow path. The molten material flow path and the gas components inside the cavity are flowed and discharged until the tip of the molten material flow portion branched to the left and right reaches the gas discharge structure A. Until the flow front of the molten material collides with the first gap S1, when the molten material has a low viscosity and a high flow rate, it exerts a powerful discharge action, and the venturi effect causes the remaining flow path and the inside of the cavity to be low pressure. The effect of reducing the pressure to (negative pressure) can be expected. As a result, it is easy to press the flow material into the cavity, which has a good influence on the molding action. When the flow front of the molten material collides with the gap S1 and pushes down the sliding member 10, the gas discharge port is closed and the molten material is filled in the cavity.

As in these typical arrangements, the direction of flow from the gate into which the molten material is injected is determined, and preferably the exact location in the mold is the cavity shape, size, number of gates, molten material used The gas discharge structure A according to the first embodiment is arranged at the flow end by setting the necessary conditions such as the above by the flow analysis of the molten material using a computer, and the flow of the molten material is maintained in a smooth and ideal form. By doing so, it is possible to greatly reduce molding defects, improve the efficiency of molding work, and save time, materials, labor, and energy.

The gas discharge structure according to the first embodiment can be configured so as to be fitted into a mounting recess formed at a required portion in the mold, and can be configured by a fixed mold and a movable mold. In the middle of the molten material flow path connected to the filled space or the filled space, or in the vicinity of the end thereof, a mold in which the gas discharge structure is integrally disposed in advance can be obtained.

Next, a second embodiment of the gas release structure according to the present invention will be described with reference to FIGS. FIG. 2 is a diagram for explaining the configuration of the gas release structure according to the second embodiment. FIG. 2A is a plan view of the gas release structure in the initial state, FIG. 2B is a front view showing the gas release state in the initial state, and FIG. It is center sectional drawing (C). FIG. 3 is a front view (A) and a central sectional view (B) showing a state in which the gas release structure is mounted in the cavity. FIG. 4 is a front view (A) and a central sectional view (B) showing a state in which the molten material filled in the cavity has entered the flow path and the upper end of the sliding member by the movement of the sliding member, and at the time of mold release. FIG. 5C is a view (C) illustrating a state in which the gas release structure is pulled out from the tab by an inclined slide mechanism. FIG. 5 is a view for explaining an attachment position and a tab of the gas release structure according to the second embodiment. Reference numerals of the same parts as those in FIG. 1 are omitted, description of the same configuration and operation functions as those in the first embodiment in FIG. 1 is omitted, and configurations and operation functions different from those in the first embodiment will be described.

The gas discharge structure according to the second embodiment of the present invention is mounted orthogonally below the vicinity of the center of the bottom surface of the cavity C as shown in FIGS. 3 to 5, and the gas discharge structure according to the first embodiment. It is set as the structure which added the inclination slide mechanism to. As in the first embodiment, the gas release structure according to the second embodiment includes a sliding member 10 and a sliding member receiver 30 as shown in FIG. The sliding member 10 is accommodated in a first gap S1 below the flow path 31 formed on the upper surface portion of the sliding member receiver 30, and the fluid from the cavity passes through the flow path 31. Then, it will be received in the gap S1. Since the configuration and operation functions of the sliding member 10 are the same as those in the first embodiment, description thereof is omitted.

As shown in FIGS. 2 and 3, the sliding member receiver 30 is formed by projecting a flow path 31 for receiving a fluid from an opening CH opened near the center of the bottom surface of the cavity C on the upper surface. The first gap S1 communicating with the flow path 31 is secured in the lower part of the upper surface to receive the sliding member 10. The sliding member receiver 30 is an inclined shaft 32 in which the lower portion 30b of the receiving portion 30a of the sliding member on the surface portion of the sliding member receiver and the back portion 30c of the sliding member receiver are inclined surfaces. It has an inclined slide mechanism and also has the function of an inclined slide mechanism. The gas discharge port 33 is formed to extend to the back side of the sliding member receiver.

The operation and function of the gas release structure according to the second embodiment of the present invention will be described. Prior to the description, an inclined slide mechanism and a tab (remaining wall) will be described. As described above, Patent Document 3 discloses an inclined slide mechanism for releasing an undercut portion of a resin molded product, and the molded product is extracted from the undercut portion while pushing up the molded product by raising the inclined slide. Is released. In addition, when the gas release structure is three-dimensionally mounted perpendicular to the lower part of the cavity C as shown in FIG. 5, the melt that has entered the upper end of the sliding member when moved down by the pressing force of the molten material tip The raw material is formed as a tab (extra-wall) that is not necessary for the molded product.

As shown in FIG. 4C, the gas release structure according to the second embodiment pushes the molded product up by the sliding operation toward the ascending direction U of the inclined shaft 32 at the time of mold release. It operates to move out of the tab T by moving in the horizontal direction H. By this operation, the tab formed in the molded product is released without being broken or damaged, and the occurrence of a dent on the surface of the molded product can be prevented, and the occurrence of product defects is greatly reduced.

Examples of the elastic body that presses the sliding member 10 according to the present invention against the opposing surface include a coil spring, a leaf spring, a rubber-based elastic body, a fluid compression actuator, and the like, and a combination of one or more of these is employed. can do.

In addition to a simple structure consisting of a sliding member and a sliding member receptor, the gas discharge structure in the mold according to the present invention is released by self-actuation with high accuracy and without time delay, Since it has a structure that forms a gap for receiving the molten material and an inclined surface that seals the gap, when the tip of the fluidized part of the molten material reaches the gas discharge structure, it operates without any delay and flows out of the molten material to the outside. Can be prevented. In the gas discharge structure inside the mold, the sliding body itself becomes a sensor that determines the operation timing, and at the same time, so-called self-control is performed, which functions as a control mechanism. Therefore, not only a sensor for detecting a phenomenon but also a solenoid means for driving valves, an operation driving unit such as a hydraulic cylinder, and the like are not necessary. Therefore, it is advantageous in terms of materials used, processing time, production cost, etc., and a time delay in operation can be almost ignored, so that molding defects caused by gas in the cavity can be greatly reduced.

As a result of making it possible to prepare a gas discharge structure in the mold as a single unit as in the present invention, a new mold and a modification that forms a recess as an attachment portion in an appropriate part of the conventional mold are mounted. Therefore, it can be expected to greatly improve the molding efficiency. When a mold having a single gas discharge structure is no longer needed, only this mechanism can be removed and used in another mold. In particular, it is necessary to finish the molds for taking in fashion or satisfying the demand only for a short period of time, which is called seasonal goods, but it is necessary to finish it as cheap as possible. However, since the gas discharge structure according to the present invention can be diverted, From the viewpoint of manufacturing time and the like, it is preferable. Moreover, in the metal mold | die which can be used for a long period of time, the metal mold | die incorporating the gas discharge | release structure by the same structure can also be manufactured integrally, and economical efficiency improves.

Further, the gas discharge structure in the mold according to the present invention can be mounted three-dimensionally orthogonally below the vicinity of the bottom center of the cavity, and has an inclined slide mechanism for releasing the tab, The tab formed by the molten material that has entered the upper end of the sliding member can be efficiently released, and the range of the types of molded articles that are targeted is widened.

Claims

A sliding member that receives a pressing force by an elastic body from the opposite surface side, the upper side is an inverted trapezoidal cross section, the lower side where the elastic body is mounted on the bottom surface is a rectangular parallelepiped shape, and the upper surface is from the molten material filling space A first gap for receiving the fluid is secured, and a second gap and a second gap that are communicated with the first gap and serve as a gas flow path are formed on both side surfaces extending from both ends of the upper surface to the bottom of the gas discharge port. A sliding member that secures a gap of 3 and forms the first inclined surface and the second inclined surface;
The sliding member is slidably received in the flow direction of the molten material, the first gap is secured on the upper surface, and the first inclined surface and the second inclined surface corresponding to the first inclined surface and the second inclined surface are provided on both inner side surfaces. 3 and the fourth inclined surface are formed, and the gas release which is blocked when the sliding member moves to the bottom position of the gas discharge port in the direction against the elastic body by the flow front end of the molten material. A gas release structure that is mounted in the middle of the molten material flow path formed by a stationary mold and a movable mold having a sliding member receiver and a movable mold, or in the middle of the molten material flow path connected to the filled space, or near the end. Because
While the fluid from the molten material filling space is a gas, the first gap, the second gap, and the third gap are passed as flow passages and discharged to the outside through a gas discharge port communicating with them. When the fluid moves from the gas to the molten material, the sliding member moves to the bottom position of the gas discharge port to close the gas discharge port 23, and the first inclined surface, the third inclined surface, and the second The inclined surface and the fourth inclined surface are closely engaged with each other and are in close contact with each other, so that the second gap and the third gap are sealed, and the subsequent passage of the molten material is prevented. The gas release structure in the mold.
The gas discharge structure according to claim 1, wherein the gas discharge structure is mounted orthogonally below a central portion of the bottom of the molten material filling space and includes an inclined slide mechanism,
The sliding member receiver has a flow path for receiving a fluid projecting from an opening portion opened near the center of the bottom surface of the molten material filling space, protruding from the upper surface, and communicated with the flow channel at a lower portion of the upper surface. 1 to secure the gap and receive the sliding member,
Then, an inclined shaft having inclined surfaces at the lower portion and the back surface of the sliding member receiving portion on the surface of the sliding member receiving body is formed, and a molded product is formed by a sliding operation toward the rising direction of the inclined shaft at the time of releasing. It is configured to move in the horizontal direction while being pushed up and to come out of the tab formed by the molten material that has entered the upper end of the sliding member when the sliding member moves to the bottom position of the gas discharge port. Characteristic gas release structure in the mold.
2. The elastic body that presses the sliding member against the opposing surface is composed of one or a plurality of combinations selected from a coil spring, a leaf spring, a rubber-based elastic body, and a fluid compression actuator. Or the gas discharge | release structure in the metal mold | die in any one of 2.
4. The gas discharge structure in a mold according to claim 1, wherein the gas discharge structure can be fitted and mounted in a mounting recess formed at a required portion in the mold.
The gas release structure in the mold according to any one of claims 1, 3, and 4 is a middle part of a molten material flow space formed by a fixed mold and a movable mold or a molten material flow path connected to the filled space. A mold characterized in that it is disposed integrally in the vicinity of the end.