JP4672898B2 - Molding system for resin molded products - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a molding system for resin molded products suitable mainly for molding small molded products.
[0002]
[Prior art]
In general, an injection mold for molding a resin molded product having the same shape has a cavity formed between a fixed mold and a movable mold. The fixed mold is provided with a resin injection port, and the resin injection port communicates with the cavity through a hot runner. A gate valve is provided between the end of the hot runner and the cavity, and the molten resin is filled into the cavity by opening the gate valve. A cooling water channel is provided around the cavity so that the molten resin filled in the cavity is cooled and solidified.
[0003]
In a multi-molding mold in which a single injection mold is used to mold a plurality of molded products simultaneously, a plurality of cavities are provided, and a hot runner is branched to each gate valve. The molten resin injected from the resin injection port is distributed by the hot runner and filled in each cavity.
[0004]
[Problems to be solved by the invention]
By the way, when molding a molded product with the injection mold configured as described above, after fixing the fixed mold and the movable mold, the molten resin is injected into the cavity from the injection molding machine through the resin injection port. And wait for the molten resin in the cavity to cool and solidify. Then, after the molten resin is cooled and solidified, the fixed mold and the movable mold are separated from each other, and the molded product is taken out. Thus, there is a problem that the molding cycle time is long.
[0005]
In addition, there is a limit to the size of a molded product that is molded by an injection mold, and it is impossible to mold a micro-molded product of several millimeters.
[0006]
This invention has been made in view of the above circumstances, the place to this purpose, even micro-molded article, short formed shape cycle time, provide a molding system for molded articles which can improve productivity There is to do.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a molding unit that molds a molded product with a hot runner block having a resin passage through which a molten resin flows and a molten resin that is provided in the middle of the resin passage. A cooling unit that cools the molded product molded by the molding unit, and a moving unit that moves the cooling unit to the molding unit to cool the molded product, and the molding unit includes the resin A pair of resin clamp spindles that are provided so as to be able to advance and retract in a direction crossing the passage and chuck the molten resin flowing through the resin passage, and are provided inside the resin clamp spindle so as to be able to advance and retract independently of the resin clamp spindle. A pair of pressure molding spindles for pressure molding the chucked molten resin, and a cavity provided on the end surface of the pressure molding spindle In the molding system of the resin molded article, characterized in that it is composed of a I.
[0008]
A second aspect of the present invention provides a hot runner block having a resin passage for circulating a molten resin, a molding portion having a molding unit for molding a molded product by the molten resin provided in the middle of the resin passage, and molded by the molding unit. A cooling unit that cools the molded product and a moving means that cools the molded product by moving the cooling unit to the molding unit, and the molding unit is provided so as to be able to advance and retreat in a direction crossing the resin passage. A pair of resin clamp spindles for chucking molten resin flowing through the resin passage, a cavity provided on at least one end face of the resin clamp spindle, and the cavity provided independently of the resin clamp spindle so as to advance and retreat A resin molding product molding characterized by comprising a pressure molding spindle for pressure molding the molten resin inside. In the Temu.
[0009]
A third aspect of the present invention provides the resin passage according to the first or second aspect, wherein the resin passage has a receiving portion for a molten resin injected from a resin injection portion for injecting the molten resin, and the excess molten resin that has passed through the molding unit is injected into the resin. It is a molten resin circulation path to be refluxed to the part.
[0010]
According to a fourth aspect of the present invention, the cooling unit according to the first or second aspect includes a cooling block having a cooling water channel, and an air nozzle provided in the cooling block to inject air into the molded product to drop the molded product from the molded unit. It is comprised from these.
[0011]
According to a fifth aspect of the present invention, the pressure molding spindle according to the first aspect includes a pair of spindles having recesses that form cavities in mutually facing end faces, and the molten resin is primarily pressurized by abutting the end faces of the spindles. After that, a drive mechanism for increasing the density of the molten resin by secondary pressure is provided.
[0012]
According to the above configuration, a part of the molten resin flowing through the resin passage is chucked by the pair of resin clamp spindles, and the chucked molten resin is pressed by the pair of pressure forming spindles having the cavities to be molded. It is possible to continuously perform the cooling by moving the molded product to the cooling unit.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
1 to 4 show a first embodiment, and FIG. 1 is a perspective view schematically showing an overall configuration of a resin molding product molding system. As shown in FIG. 1, the molding system 1 is provided with a slide unit 2 that is movable in the left-right direction (arrow X direction). A first air cylinder 3 as a moving means fixed to the base 1 or the like is connected to one end of the slide unit 2 in the left-right direction so that the slide unit 2 moves in the left-right direction.
[0015]
Rising walls 4 a and 4 b are provided at both left and right ends of the slide unit 2, and a recess 5 is formed between the rising walls 4 a and 4 b of the slide unit 2. A manifold block 6 is provided in the recess 5 in a direction orthogonal to the slide unit 2, and this is supported in a horizontal state by a plurality of columns 7.
[0016]
Rails 8 are provided on both sides along the longitudinal direction of the slide unit 2 in the left-right direction. The rails 8 are supported by rail support blocks 9 provided on the manifold block 6. The slide unit 2 moves with respect to the manifold block 6.
[0017]
The manifold block 6 will be described as shown in FIGS. That is, a resin injection port 10 as a receiving portion is provided on the end face in the intermediate portion in the width direction of the manifold block 6. The resin injection port 10 is provided with a nozzle touch surface 10 a to which the nozzle 12 of the resin injection cylinder 11 is joined. The resin injection port 10 is provided with a resin passage 13 through which the molten resin a flows.
[0018]
The resin passage 13 includes a lower passage 13a extending in the lateral direction in the vicinity of the lower portion of the manifold block 6, a rising passage 13b extending in the vertical direction from the end of the lower passage 13a, and the manifold block 6 extending from the end of the rising passage 13b. An upper passage 13c extending in the lateral direction in the vicinity of the upper portion of the upper passage 13c and a descending passage 13d extending in the vertical direction from the end of the upper passage 13c.
[0019]
An opening / closing valve 14 is provided in the descending passage 13 d, and a nozzle 14 a of the opening / closing valve 14 communicates with the resin injection cylinder 11. Accordingly, the resin passage 13 is formed in a circulation path for circulating the molten resin a. Further, a heater 15 is embedded in both sides of the resin passage 13 and around the opening / closing valve 14 to form a hot runner block 16.
[0020]
The resin passage 13 is a long hole whose cross section is flat in the vertical direction, and a molding portion 18 of the molding unit 17 is provided orthogonal to the resin passage 13. That is, a resin clamp spindle 19 constituting the molding unit 17 is installed between the rising walls 4 a and 4 b of the slide unit 2. The resin clamp spindle 19 is a cylindrical pipe having an outer diameter smaller than the vertical dimension of the resin passage 13, and the molten resin a flows between the outer peripheral surface of the resin clamp spindle 19 and the inner periphery of both ends of the resin passage 13. A space portion 13e is provided.
[0021]
The resin clamp spindle 19 is divided into two parts by a molding part 18, and each base end part is fitted into a support hole 20 provided in the rising walls 4 a and 4 b so as to be slidable in the axial direction. The rising walls 4 a and 4 b are provided with a first cylinder 21 communicating with the support hole 20, and a first piston 22 is provided in the first cylinder 21 so as to be movable in the axial direction of the resin clamp spindle 19. It has been.
[0022]
A flange portion 19 a is provided at the base end portion of the resin clamp spindle 19, and the flange portion 19 a is directly connected to a first piston 22 as a drive mechanism by a fixing ring 23 and a bolt 24. The first cylinder 21 is divided into a front chamber 21a and a rear chamber 21b by a first piston 22, and the front chamber 21a and the rear chamber 21b communicate with an air supply source (not shown) via air ports 25a and 25b, respectively. Has been. The resin clamp spindle 19 is advanced and retracted by the first piston 22, and the end surface is brought into contact with and separated from the molding portion 18.
[0023]
In addition, a pressure forming spindle 26 that is independently movable forward and backward is inserted in the resin clamp spindle 19. The pressure forming spindle 26 is a thick cylindrical pipe, and a protruding pin 27 is inserted therein so as to be able to advance and retract independently.
[0024]
The pressure forming spindle 26 and the ejecting pin 27 are also divided into two at the intermediate portion, and a cavity 28 is formed by the end surfaces facing each other of the pressure forming spindle 26, and the end surfaces facing each other of the projecting pin 27 sandwich the molded product b. It can be done.
[0025]
A proximal end portion of the pressure forming spindle 26 passes through the first cylinder 21 and the first piston 22. A second cylinder 29 is provided inside the first piston 22, and a second piston 30 as a drive mechanism is movable in the axial direction of the pressure forming spindle 26 inside the second cylinder 29. Is provided.
[0026]
A flange portion 26 a is provided at the base end portion of the pressure forming spindle 26, and the flange portion 26 a is directly connected to the second piston 30. The second cylinder 29 is divided into a front chamber 29a and a rear chamber 29b by a second piston 30, and the front chamber 29a and the rear chamber 29b communicate with an air supply source (not shown) via air ports 31a and 31b, respectively. Has been. Then, the pressure forming spindle 26 is advanced and retracted by the second piston 30, and the end surfaces forming the cavities 28 are brought into contact with and separated from each other.
[0027]
Further, the base end portion of the protruding pin 27 passes through the second piston 30 and protrudes to the outside, and the protruding pin 27 is connected to an air cylinder (not shown). Then, the projecting pin 27 is advanced and retracted by the air cylinder so that the molded product b can be clamped or released.
[0028]
Further, first and second cooling portions 33 and 34 are provided on both left and right sides of the manifold block 6 so as to be fitted to the resin clamp spindle 19. The first and second cooling sections 33 and 34 have a ring-shaped cooling block 35 and are fixed to the manifold block 6 by bolts 36.
[0029]
The cooling block 35 is provided with an air nozzle 37 facing the molded product b at the upper part with the molding unit 17 in between, and at the lower part is provided a drop port 38 for dropping the molded product b. A cooling water channel 39 is provided in the cooling block 35 to forcibly cool and solidify the molded product b.
[0030]
Next, the operation of the molding system 1 configured as described above will be described.
[0031]
When molten resin a such as polypropylene is injected from the nozzle 12 of the resin injection cylinder 11, the molten resin a flows through the resin passage 13 of the hot runner block 16.
[0032]
In this state, when air is supplied from the air port 25b to the rear chambers 21b of the pair of left and right first cylinders 21, the first piston 22 moves forward by the air pressure. Accordingly, each of the resin clamp spindles 19 moves forward, and when the end surface hits as shown in FIG. 4A, the molten resin a flowing in the resin passage 13 is chucked. That is, since the resin clamp spindle 19 has a pipe shape, a part of the molten resin a flowing through the resin passage 13 is taken into the resin clamp spindle 19 at the same time as the end surface abuts. At this time, the molten resin a outside the resin clamp spindle 19 flows through the resin passage 13 via the space 13e.
[0033]
Immediately after the forward movement of the resin clamp spindle 19, when air is supplied from the air port 31b to the rear chamber 29b of the pair of left and right second cylinders 29, the second piston 30 moves forward by the air pressure. Accordingly, the pressure molding spindle 26 moves forward, and the ejection pin 27 moves forward by the second air cylinder 32.
[0034]
Therefore, the molten resin a taken in by the resin clamp spindle 19 is filled in the cavity 28 formed by the pressure molding spindle 26 and the end face of the ejection pin 27 and is subjected to the primary pressure. In this state, as shown in FIG. 4A, there is a slight gap g between the pressure molding spindle 26 and the molten resin a, but the second piston 30 further advances and the resin clamp spindle 19 is moved. When the second pressurization is performed for the stroke corresponding to the gap g, the resin density in the cavity 28 is increased, and a molded product b suitable for fine precision parts with high density is formed.
[0035]
Next, the first cylinder 3 is driven and the slide unit 2 moves to the left. The molded product b sandwiched between the pressure molding spindle 26 and the end face of the ejection pin 27 faces the cooling block 35 of the first cooling unit 33. Since the cooling block 35 is always cooled by the cooling water flowing through the cooling water channel 39, the molded product b is forcibly cooled.
[0036]
Next, when air is supplied from the air ports 25a and 31b to the front chamber 21a of the pair of left and right first cylinders 19 and the front chamber 29a of the second cylinder 29, the first piston 22 and the first piston 22 The second piston 30 moves backward. Accordingly, since the resin clamp spindle 19 and the pressure molding spindle 26 are moved backward, the molded product b faces the air nozzle 37 as shown in FIG.
[0037]
And the air injected from the air nozzle 37 is sprayed on the molded article b. Further, when the protruding pin 27 is retracted by the air cylinder, the molded product b held by the end surface of the protruding pin 27 is separated from the protruding pin 27 by the pressure of the air and falls from the dropping port 38.
[0038]
At this time, since the resin passage 13 in the molding portion 18 is blocked by the outer peripheral wall of the resin clamp spindle 19, the molten resin a does not flow into the molding portion 18. The resin passage 13 includes a lower passage 13a, an ascending passage 13b, an upper passage 13c, and a descending passage 13d. Since the descending passage 13d is formed in a circulation passage communicating with the resin injection cylinder 11, the opening / closing valve 14 The molten resin a can be returned to the resin injection cylinder 11 by opening.
[0039]
When the cooling of the molded product b is completed, the first air cylinder 3 is driven again to move the slide unit 2 to the right, and the molding part 18 faces the butted portions of the resin clamp spindle 19 and the pressure molding spindle 26. Similarly to the above, a part of the molten resin a flowing through the resin passage 13 is taken into the resin clamp spindle 19 and molded by the pressure molding spindle 26.
[0040]
FIG. 5 shows a second embodiment and is a cross-sectional view showing a state in which pressure is applied by a pressure forming spindle. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, molding blocks 40 are embedded in mutually facing end surfaces of a pair of pressure molding spindles 26, and arc-shaped concave portions 41 are formed on the mutually facing end surfaces of the molding block 40, for example, a lens molding cavity. 42 is formed. Further, the resin clamp spindle 19 is moved forward by a pair of the resin clamp spindles 19 when the molten resin a is taken in, and the end surfaces thereof are brought into contact with each other. By blocking the molten resin a, it is possible to prevent burrs from occurring between the end surfaces of the resin clamp spindle 19.
[0041]
FIG. 6 shows a third embodiment, and the same components as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 6A is a cross-sectional view showing a state in which a molten resin is taken in by a resin clamp spindle, and FIG. 6B is a cross-sectional view showing a state in which pressure is applied by a pressure molding spindle.
[0042]
In the present embodiment, for example, an arcuate cavity 45 and an ejection pin 27 for molding a lens are provided on one of a pair of resin clamp spindles 44, and a pressure molding spindle 46 and an ejection pin 27 are provided on the other. . A flat surface is formed on the end surface of the pressure forming spindle 46 facing the cavity 45.
[0043]
According to this embodiment, when the resin clamp spindle 44 takes in the molten resin a, the pair of resin clamp spindles 44 advances simultaneously and the end faces come into contact with each other. Is advanced by pressing in the direction of the cavity 45 and press-molding the molten resin a, and the resin density in the cavity 46 can be increased.
[0044]
In the embodiment, the slide block, the resin clamp spindle, the pressure molding spindle, and the ejection pin are driven by the air cylinder. However, for example, the position may be detected by a servo motor and driven. The drive source is not limited.
[0045]
In addition, by making the pressure molding spindle with cavities interchangeable, it is possible to configure a molding system that molds molded products with different shapes, which greatly reduces costs compared to conventional injection molds. Can be achieved.
[0046]
【The invention's effect】
As described above, according to the present invention, a part of the molten resin flowing through the resin passage is chucked by the pair of resin clamp spindles, and the chucked molten resin is collected by the pair of pressure molding spindles having the cavities. pressed and molded, it is so arranged that the cooling by moving the shaped molded article to a cooling unit, can shorten the forming shape cycle time, it is possible to improve the productivity.
[Brief description of the drawings]
FIG. 1 is a perspective view of an entire molding system showing a first embodiment of the present invention.
2A is a side view of a manifold block, and FIG. 2B is a cross-sectional view taken along line AA.
FIG. 3 is a longitudinal side view of the slide block and the manifold block, showing the embodiment.
4A and 4B show the embodiment, in which FIG. 4A is a longitudinal side view of a molding portion, and FIG.
FIG. 5 shows a second embodiment of the present invention, and is a longitudinal side view of a molded part.
FIGS. 6A and 6B show a third embodiment of the present invention, in which FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Molding system 13 ... Resin passage 16 ... Hot runner block 17 ... Molding unit 18 ... Molding part 19 ... Resin clamp spindle 26 ... Pressure molding spindle 27 ... Extrusion pins 33, 34 ... Cooling part

Claims (5)

A hot runner block having a resin passage for circulating a molten resin, a molded portion having a molding unit for molding a molded product by a molten resin provided in the middle of the resin passage, and a molded product molded by the molding unit. A cooling unit for cooling, and moving means for moving the cooling unit to the molding unit to cool the molded product,
The molding unit includes a pair of resin clamp spindles that are provided so as to be able to advance and retreat in a direction crossing the resin passage and chuck the molten resin flowing through the resin passage, and the resin clamp spindle is independent of the resin clamp spindle. A resin molding comprising a pair of pressure molding spindles that press-mold a chucked molten resin that is provided so as to freely advance and retract, and a cavity provided on an end surface of the pressure molding spindle. Product molding system. A hot runner block having a resin passage for circulating a molten resin, a molded portion having a molding unit for molding a molded product by a molten resin provided in the middle of the resin passage, and a molded product molded by the molding unit. A cooling unit for cooling, and moving means for moving the cooling unit to the molding unit to cool the molded product,
The molding unit includes a pair of resin clamp spindles that are provided so as to be capable of advancing and retreating in a direction crossing the resin passage and chucking a molten resin flowing through the resin passage, and a cavity provided on at least one end surface of the resin clamp spindle And a pressure molding spindle which is provided independently of the resin clamp spindle so as to be movable forward and backward and press-molds the molten resin in the cavity. The resin passage is a molten resin circulation passage that has a receiving portion for a molten resin injected from a resin injection portion that injects a molten resin, and returns the molten resin that has passed through the molding unit to the resin injection portion. The molding system for a resin molded product according to claim 1 or 2. The cooling unit includes a cooling block having a cooling water channel, and an air nozzle that is provided in the cooling block and injects air onto the molded product to drop the molded product from the molded unit. Item 3. A molding system for a resin molded product according to Item 1 or 2. The pressure forming spindle includes a pair of spindles having recesses that form cavities on opposite end surfaces. The end surfaces of the spindles abut each other to first press the molten resin, and then secondarily press the molten resin. A molding system for a resin molded product according to claim 1, further comprising a drive mechanism for increasing the density of the resin molded product.

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