JP2018192758A - Injection molding machine - Google Patents

Abstract

To provide an injection molding apparatus which can be miniaturized and can manufacture molded articles of desired accuracy with various sizes with simple control.SOLUTION: In the conveying space 15, the stick-shaped molding material S 1 which has reached the position nearest to the injection nozzle 17 is completely melted into a molten state, and the whole of the subsequent stick-like molding material S 6 is still in a solidified state. The pushing-in operation of the push-in shaft 25 pushes out the stick-form molding material S 7 and feeds it into the conveying space 15, and the leading molten stick-shaped molding material S 1 is ejected toward the molds 55, 57. By the reciprocating movement of the push-in shaft 25 in the advancing and retracting direction as described above, the stick-shaped molding material S is sequentially supplied to the conveying space 15 in the manner of dropping the dharma and the stick-shaped molding material S is sequentially ejected from the head from the beginning. The pushing-in shaft 25 can inject a plurality of stick-shaped molding materials S to the mold side by repeatedly pushing in operation.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a compact and simplified injection molding apparatus.

  In a conventional injection molding apparatus, as described in Patent Document 1, a synthetic resin molding material is charged in a pellet or the like from a hopper, plasticized and melted in a heating cylinder, and then conveyed by a screw. It is injected into the mold cavity and molded. Then, after the molded product is solidified, the mold is opened and the molded product is pushed out by an ejector pin.

  In such an injection molding apparatus, the heating cylinder and the mold are separate bodies, and the device from the control surface of the structure and molding conditions is devised independently to achieve optimum performance for each, As the entire apparatus becomes larger, the control of molding conditions has become complicated.

JP 2008-302634 A JP 2012-30429 A

Recently, the time and effort required to transport molded products has become a problem, and it is also proposed to eliminate the transportation itself by allowing each end user to manufacture as many molded products as necessary. Has been. However, since the conventional injection molding apparatus was large as described above, it was difficult to respond to this proposal.
On the other hand, we previously proposed an injection molding apparatus as Patent Document 2 that can be miniaturized and can produce a molded product with a desired accuracy with simple control and can be installed at the end user's site. .
Since this device can inject at low pressure, the casting surface is clean and highly evaluated in this respect, and if it can be improved to cope with the diversification of molded products, especially the increase in size, the versatility will increase. Become.
Thus, the larger the molded product, the larger the mold and the greater the amount of resin to be supplied to it. However, in spite of the mold, if the resin supply mechanism side is designed easily and large, this device The advantage of downsizing, which is the first feature of, is impaired.

  The present invention has been made by paying attention to the above-mentioned conventional problems, and is intended to increase the size of a molded product while taking advantage of the idea of downsizing and low-pressure injection molding of the injection molding device described in Patent Document 2. It is an object of the present invention to provide an injection molding apparatus that can cope with the above and has increased versatility.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The invention of claim 1 is a mold comprising a lower mold and an upper mold that forms a cavity together with the lower mold, and a tip is a nozzle. A horizontal injection cylinder that communicates with the cavity and the inside; heating means that generates a temperature gradient that rises from the base end side toward the nozzle inside the injection cylinder; and an inside of the injection cylinder from the base end side A push-in means having a push-in shaft that can enter and move back and forth in the axial direction; and a closing portion adjacent to a proximal end side of the injection tube, and the inside of the injection tube has a plurality of stick shapes inserted from the input portion It is set so that the molding material is housed in a state aligned in a line in the longitudinal direction, and the input portion is a stock guide portion that stacks and stocks a plurality of the stick-shaped molding materials in a laid down state, An injection characterized in that it is composed of an insertion port provided opposite to both sides in the longitudinal direction of the stick-shaped molding material located in the lower stage, and the insertion port is arranged in the middle of the advance / retreat stroke of the push-in shaft It is a molding device.

  According to a second aspect of the present invention, in the injection molding apparatus according to the first aspect, the stock guide portion is open at the top to form a replenishing port, and is detachably inserted into the replenishing port and stacked in a stick shape. An injection molding apparatus comprising a weight portion that descends following the descending material as an accessory.

  According to a third aspect of the present invention, in the injection molding apparatus according to the second aspect, the weight portion is provided with a locking portion that is locked to the lip of the replenishing port and is further prevented from descending. It is an injection molding device characterized.

  According to a fourth aspect of the present invention, there is provided the injection molding apparatus according to any one of the first to third aspects, wherein the input portion is formed separately from the injection cylinder.

  According to a fifth aspect of the present invention, in the injection molding apparatus according to any one of the first to fourth aspects, the capacity of the cavity of the mold is set to be larger than the injection amount of the molding material per time by the pressing of the pressing shaft. It is an injection molding device characterized by having.

  According to the injection molding apparatus of the present invention, a molded product with a desired accuracy can be manufactured with a small size and simple control. Moreover, it is possible to cope with the case where the size of the molded product is desired to be increased.

1 is a perspective view of an injection molding apparatus according to an embodiment of the present invention. It is a side view of the injection molding apparatus of FIG. It is a partially broken view of the injection molding apparatus of FIG. It is a partial cross section figure corresponding to FIG. 3 of the injection molding apparatus of FIG. It is a partially broken view of the injection molding apparatus of FIG. FIG. 6 is a partial cross-sectional view corresponding to FIG. 5 of the injection molding apparatus of FIG. 1. It is a perspective view of the stick-shaped molding material used for the injection molding apparatus of FIG.

An injection molding apparatus 1 according to an embodiment of the present invention will be described with reference to the drawings.
1 and 2, reference numeral 3 denotes a rectangular plate-shaped base portion. A portion of the base portion 3 extending from the right end in the longitudinal direction to a length of about 2/3 toward the left is a pair that rises from the longitudinal edge. The rectangular plate-shaped mounting portion 7 is lifted and supported by the support walls 5 and 5 to form a mounting table 9.

A molding material supply / injection mechanism 11 is mounted on the mounting table 9.
Reference numeral 13 denotes an injection cylinder. The injection cylinder 13 has a cylindrical shape, and the inner peripheral surface and the outer peripheral surface are coaxial as shown in FIG. Further, both the inner peripheral surface and the outer peripheral surface have substantially the same diameter in any cross section with respect to the axial direction. The inside of the injection cylinder 13 is a molding material conveyance space 15 which is a resin raw material. An injection nozzle 17 is coaxially attached to the tip of the injection cylinder 13 in the axial direction, and the conveyance space 15 of the injection cylinder 13 and the nozzle hole of the injection nozzle 17 communicate with each other. On the other hand, the base end side in the axial direction is opened entirely to serve as a molding material receiving port 19.

  A heater 21 that generates heat when energized is embedded in the meat portion of the injection cylinder 13, and the meat portion is composed of a plurality of materials 13A to 13E having different thermal conductivities. Therefore, when the heater 21 is energized, a temperature gradient is generated in the conveyance space 15, and the nozzle hole side of the injection nozzle 17 is the highest and the receiving port 19 side is the lowest.

The injection cylinder 13 is mounted on the mounting table 9 in a lying state so that the axial direction coincides with the horizontal direction. Reference numeral 23 denotes a holding block. A base end portion of the injection cylinder 13 is fixed to the holding block 23 and is supported by being lifted to a certain height. The axial direction of the injection cylinder 13 faces the left-right direction.
Reference numeral 25 denotes a pushing shaft. The pushing shaft 25 has an elongated cylindrical shape with the same diameter and the same diameter, and the tip surface is a pressing surface 27 perpendicular to the axial direction. The outer diameter of the push-in shaft 25 is slightly smaller than the inner diameter of the injection cylinder 13, and when it is inserted coaxially into the conveyance space 15 of the injection cylinder 13, smooth advance / retreat movement is possible.

  An air cylinder 29 is fixed to the mounting table 9 as a driving means for the push-in shaft 25. The proximal end side of the push-in shaft 25 is coaxially connected to the piston rod 31 of the air cylinder 29 via a connecting member 33 and is cantilevered. Accordingly, the push-in shaft 25 moves following the piston rod 31 that moves forward and backward.

  On the mounting portion 7, the injection cylinder 13 is installed on the left side and the air cylinder 29 is installed on the right side, and the injection cylinder 13 is connected to the front side of the pushing shaft 25 connected to the air cylinder 29. The receiving port 19 is facing. The movement trajectory of the push-in shaft 25 coincides with the axial direction of the transport space 15 of the injection cylinder 13, and when the push-in shaft 25 reaches the stroke end, the push-in shaft 25 enters the transport space 15 of the injection cylinder 13 and at the time of retraction from the receiving port 19. The arrangement relationship has been adjusted so that it is in front.

  Reference numeral 35 denotes a loading unit, and the loading unit 35 is installed as a separate body on the right side of the holding block 23. The feeding portion 35 is a box-shaped stock guide portion 37 in the upper half. The stock guide portion 37 is fully open at the top to form a supply port 39. The stock space 41 inside the stock guide portion 37 has an elongated rectangular cross section on the horizontal direction side. The upper edge of the wall portion on the long side widens as a tapered surface 43, and the supply port 39 is larger than the stock space 41 so that the molding material can be easily inserted. Further, insertion holes 45 and 45 are formed in the opposing short-side walls, respectively. The insertion space 45 opens the stock space 41 in two directions on the bottom surface side.

The insertion portion 35 is installed between the holding block 23 and the air cylinder 29 when viewed from the left-right direction, and the insertion port 45 is located on the movement locus of the push shaft 25 connected to the air cylinder 29 on the side of the traveling direction. , 45 are arranged to face.
Therefore, when the push-in shaft 25 advances, it passes through the insertion openings 45 and 45 and enters the conveyance space 15 of the injection cylinder 13, and retracts to the front of the stock guide portion 37 when retracted. That is, the two insertion openings 45 and 45 are arranged in the middle of the advance / retreat stroke of the push-in shaft 25.

The replenishing port 39 of the insertion portion 35 can be closed with an accessory weight portion 47. The main portion 49 of the weight portion 47 has a flat rectangular plate shape, and a wide locking portion 51 is continuously provided on the short side of the main portion 49. Therefore, when viewed from the plate surface side, it is T-shaped.
The main portion 49 is set to be slightly smaller than the stock space 41 of the stock guide portion 37, and the main portion 49 can be inserted into the stock space 41 so as to be slidable up and down when the locking portion 51 side is turned up. . However, since the locking portion 51 is locked to the edge surface of the supply port 39 and further lowering is restricted, the locking portion 51 can be easily removed from the supply port 39 by lifting the locking portion 51.

In FIG. 7, symbol S indicates a stick-shaped molding material.
In this injection molding apparatus 1, a dedicated stick-shaped molding material S is used as a raw material.
The stick-shaped molding material S has a substantially cylindrical shape, and a large number of concave grooves t extending in the axial direction are formed on the outer peripheral surface thereof. The stick-shaped molding material S is not a final molded product, has a simple shape and does not require much dimensional accuracy, and can be mass-produced at low cost.
As shown in FIG. 4, the diameter of the stick-shaped molding material S is slightly smaller than the diameter of the conveying space 15 of the injection cylinder 13, and smooth sliding is possible in the conveying space 15 even in a solid state. . The total length of the injection cylinder 13 corresponds to the total length of a plurality of stick-shaped molding materials S, in which the plurality of stick-shaped molding materials S, S,... Are aligned in a line in the longitudinal direction. Fits in.

Further, since the stock space 41 has a rectangular shape, the volume is defined by the horizontal dimension, the vertical dimension, and the height dimension, and the diameter of the stick-shaped molding material S is slightly smaller than the lateral dimension of the stock guide portion 37. The length of the stick-shaped molding material S in the axial direction is slightly smaller than the vertical dimension of the stock space 41. Further, the height dimension (vertical dimension) of the stock space 41 is at least four times the diameter of the stick-shaped molding material S. Therefore, as shown in FIG. 4, in the stock space 41, a plurality of stick-shaped molding materials S, S,...
At that time, the insertion openings 45, 45 of the stock guide portion 37 are opposed to both end surfaces in the axial direction of the stick-shaped molding material S located at the lowest level. Therefore, the lowermost stick-shaped molding material S is in a state of being connected to the succeeding row of the stick-shaped molding materials S, S,... Stored in the conveyance space 15 of the injection cylinder 13.

A mold device 53 is mounted on the left side of the base portion 3 in the longitudinal direction.
The mold of the mold apparatus 53 includes an upper mold 55 and a lower mold 57. The upper die 55 is on the fixed side, and the lower die 57 is on the movable side, and the concave and convex portions are formed on the opposite surface sides so as to correspond to the shape of the molded product. When the lower die 57 is raised and closed together with the upper die 55, a cavity, a gate, a runner, and a sprue connected to the cavity are formed between the concave surface and the convex surface. The injection nozzle 17 is attached by being inserted into an attachment port formed in the upper die 55, and a molten molding material injected from the injection nozzle 17 is injected into the cavity through a sprue or the like.

The periphery of the portion where the molten molding material contacts, such as the cavities of the upper die 55 and the lower die 57, is formed of a material having good heat retention, and the remaining portion is made of a material having good heat dissipation.
Since the heat of the heater 21 is efficiently transferred to the cavity or the like through the nozzle touch of the injection nozzle 17, the molten molding material smoothly and sufficiently flows into the cavity, and immediately after sufficiently flowing into the cavity. It is designed to cool.

  Reference numeral 59 denotes a handle. The handle 59 has a generally U-shaped bar shape, and both ends thereof are connected to the drive mechanism 61 of the lower die 57. When the handle 59 is lifted upward, the lower mold 57 is lowered to open the mold.

The injection molding apparatus 1 is configured as described above, and injection molding using this apparatus will be described below.
3 and 4 show a state where the pushing operation has already progressed, and the stick-shaped molding materials S1, S2,..., S6 are already aligned in the conveying space 15 by the pushing operation. In addition, stick-shaped molding materials S7, S8, S9, and S10 are stacked on the stock guide portion 37 from the lower side, and the pressing surface 27 of the push-in shaft 25 hits the lowermost stick-shaped molding material S7. Shows the state.

Since a temperature gradient is formed in the conveyance space 15, the stick-shaped molding materials S1, S2, and S3 that have reached the position closest to the injection nozzle 17 are completely melted to form a hot water, and the subsequent stick-shaped molding is performed. The leading side of the material S4 is melted, the rear side is still in a solidified state, and the subsequent stick-shaped molding materials S5 and S6 are still in a solidified state. Since the stick-shaped molding material S6 on the side where the pushing shaft 25 hits is still in a solid state, it acts as a part of the plunger. Therefore, when the pushing shaft 25 is pushed to push the completely melted molding material, the pushing shaft does not sink into the molding material, and neither compression due to melting of the molding material occurs. In addition, the molding material melted at the end wraps around and fills the gap between the subsequent molding material and the inner surface of the injection cylinder, and the exposed surface is cooled by the heat received from the injection cylinder 13 side, and is solidified. A sealed state is created with the enclosed stick-shaped molding material S. Therefore, a stable injection pressure is ensured.
In addition, air is emitted from the melted stick-shaped molding material S, but this air quickly escapes upward through the concave groove t of the stick-shaped molding material S, so that the occurrence of voids in the molded product is significant. Reduced to

  When the push-in shaft 25 advances to the stroke end by the next push-in operation, as shown in FIGS. 5 and 6, the stick-shaped molding material S <b> 7 is pushed out, and the position where the stick-shaped molding material S <b> 6 is in the transport space 15. , And continues to the subsequent stick-shaped molding material S6. The pressed stick-shaped molding material S6 reaches the position where the preceding stick-shaped molding material S5 is present. Thus, the stick-shaped molding materials S2, S3,..., S6 proceed toward the injection nozzle 17. Then, the first completely melted stick-shaped molding material S1 is injected toward the molds 55 and 57.

After reaching the stroke end, when the push-in shaft 25 is retracted and returned to the retracted position, the stick-shaped molding material S7 is emptied from the lowermost space of the stock guide portion 37. The molding material S8 falls and fits. A weight 47 is inserted into the replenishing port 39, and the weight of the weight 47 is applied to the outer peripheral surface of the stick-shaped molding material S. Therefore, the weight 47 is not caught in the middle, and the stacked posture is not lost.
The stick-shaped molding material S8 that has come to the bottom is also pushed into the conveying space 15 of the injection cylinder 13 in the same manner.

  By the reciprocating movement of the push-in shaft 25 in the advancing and retreating direction, the stick-shaped molding materials S, S,... The materials S, S,... Are sequentially injected.

In one push of the push shaft 25, that is, in a reciprocating stroke, one stick-shaped molding material S is injected to the mold side, but the push shaft 25 can be repeatedly pushed. A plurality of parts can be injected to the mold side.
Since it is structurally easy to increase the number of stacked stages by increasing the height of the stock guide portion 37, when the stick-shaped molding material S is rapidly melted during movement, the conveyance space of the injection cylinder 13 is increased. It is only necessary to store the minimum number of stick-shaped molding materials S, and the total length can be suppressed.

The embodiment of the present invention has been described in detail above. However, the specific configuration is not limited to this embodiment, and the present invention can be changed even if there is a design change without departing from the gist of the present invention. included.
For example, in the embodiment, the molding material supply / injection mechanism 11 is mounted on the mounting table 9, but the frame member is assembled to form a rectangular parallelepiped skeleton, and the supply / injection mechanism 11 is disposed therein. It can also be configured as described above. In this case, the apparatus can be made compact.

  INDUSTRIAL APPLICABILITY The present invention is applicable to a manufacturing industry that uses a molding material to manufacture a molded product by injection molding.

DESCRIPTION OF SYMBOLS 1 ... Injection molding apparatus 3 ... Base part 5 ... Supporting wall 7 ... Mounting part 9 ... Mounting base 11 ... Supply / injection mechanism 13 ... Injection cylinder 15 ... Conveyance space 17 ... Injection nozzle 19 ... Receiving port 21 ... Heater 23 ... Holding Block 25 ... Pushing shaft 27 ... Pushing surface 29 ... Air cylinder 31 ... Piston rod 33 ... Connecting member 35 ... Input part 37 ... Stock guide part 39 ... Supply port 41 ... Stock space 43 ... Tapered surface 45 ... Insertion port 47 ... Weight Part 49 ... Main part 51 ... Locking part 53 ... Mold device 55 ... Upper mold 57 ... Lower mold 59 ... Handle 61 ... Drive mechanism S ... Stick-shaped molding material t ... (Molding material) concave groove

Claims (5)

A mold composed of a lower mold and an upper mold that forms a cavity together with the lower mold, a horizontal injection cylinder whose tip is a nozzle and communicates with the cavity, and an interior of the injection cylinder from the proximal end side Heating means for generating a temperature gradient that increases in temperature toward the nozzle, pushing means having a pushing shaft that enters the inside of the injection cylinder from the base end side and is movable back and forth in the axial direction, and a base end of the injection cylinder It has an input part adjacent to the side,
The inside of the injection cylinder is set so that a plurality of stick-shaped molding materials charged from the charging portion are stored in a state aligned in a line in the longitudinal direction,
The input section includes a stock guide section that stacks and stocks a plurality of stick-shaped molding materials in a horizontally lying state, and an insertion port that is provided on both sides in the longitudinal direction of the stick-shaped molding material located at the bottom. An injection molding apparatus characterized in that the insertion port is arranged in the middle of an advance / retreat stroke of the push-in shaft. In the injection molding apparatus according to claim 1,
The stock guide part is open at the top and serves as a replenishing port. The stock guide part is detachably inserted into the replenishing port, and is equipped with a weight part that descends as the stacked stick-shaped molding material descends. An injection molding apparatus characterized by. In the injection molding device according to claim 2,
An injection molding device, wherein the weight portion is provided with a locking portion that is locked to the lip of the replenishing port and is prevented from descending further. In the injection molding apparatus according to any one of claims 1 to 3,
An injection molding apparatus characterized in that the charging section is formed separately from the injection cylinder. In the injection molding device according to any one of claims 1 to 4,
An injection molding apparatus characterized in that a capacity of a cavity of a mold is set to be larger than an injection amount of a molding material per one time by pressing a pressing shaft.

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