JP5524120B2 - Rotary shutoff valve for injection molding machine - Google Patents

Description

  The present invention relates to a rotary shut-off valve of an injection molding machine, and more specifically, a rotor casing and a bearing that is provided at both ends of a valve bore of the rotor casing and is rotationally driven in a swinging manner. The valve bore has a molding material inlet port communicating with the heating cylinder and a molding material outlet port communicating with the injection nozzle, and the rotor is driven to the first position. Then, the molding material passage hole formed in the rotor communicates with the inlet port and the outlet port, and when driven to the second position, the state of communication between the inlet port and the outlet port is blocked. The present invention relates to a rotary shut-off valve.

  The injection molding machine is conventionally well-known, but is schematically configured as shown in FIG. That is, it comprises a plasticizing cylinder 50 in which the band heater 51 is wound on the outer peripheral portion, and a screw 52 provided in the plasticizing cylinder 50 so as to be driven in the rotational direction and the axial direction. An injection nozzle 53 is attached in front of the plasticizing cylinder 50. Therefore, when the tip of the injection nozzle 53 is touched to the mold and the screw 52 is driven to rotate, and the pellet-shaped resin material is supplied from the hopper to the plasticizing cylinder 50, as is well known, in the process of being sent forward. It is plasticized and melted and accumulated in the front weighing chamber 55. When the predetermined amount is accumulated, the screw 52 is driven in the injection direction. Then, the molten resin is injected and filled into the mold cavity. When the mold is opened after cooling and solidification, a molded product is obtained.

  As is clear from the above description, since the injection molding is intermittent molding in which plasticization and injection are alternately performed, the molten resin may leak from the injection nozzle 53 in some cases. For example, if the tip of the injection nozzle 53 is separated from the locating ring of the mold, the molten resin in the cylinder may leak from the tip of the nozzle 53 depending on molding conditions. Drooling, slang nose. If the nasal sagging occurs, quantitative molding cannot be performed, which may cause molding defects. Also, it may scatter around and cause burns. Such nasal sagging can be prevented by sucking back the screw and lowering the pressure at the tip of the plasticizing cylinder 50, but generally a shut-off valve is used. When the shutoff valve is used, the nasal sagging can be reliably prevented, and the advantage that the molding material can be shortened by plasticizing the resin material regardless of the opening and closing of the mold can be obtained.

  A foam molded product is known as one of plastic molded products molded by injection molding. The molding apparatus for the foam molded product is well known in the art as shown in Patent Documents 1 and 2 and will not be described in detail. An injection nozzle is attached in front of the plasticizing cylinder, and the inside of the injection nozzle Alternatively, a shutoff valve is provided between the tip of the plasticizing cylinder and the injection nozzle. Further, a supply port for, for example, a supercritical fluid that is a foaming agent is provided between the shutoff valve and the screw. Therefore, when the shut-off valve is closed and the screw is driven to rotate, the pellet-shaped resin supplied from the hopper is plasticized and melted and accumulated in the front in the course of being sent forward as is well known. When a predetermined amount is accumulated, supercritical fluid is injected into the front from the supercritical fluid generator. The injected supercritical fluid penetrates into the molten resin. Next, the shutoff valve is opened, and the screw is driven in the injection direction. Then, the molten resin infiltrated with the supercritical fluid is injected and filled into the mold cavity. Thereby, a foam-molded product is obtained.

  Further, for example, Patent Document 3 discloses an apparatus for molding a sandwich molded article having a shut-off valve as described above, that is, a molded article comprising a core layer and a skin layer covering the surface of the core layer. As is well known in the art. This molding apparatus comprises a main injection device for core layer molding, a sub-injection device for skin layer molding, an injection nozzle, and the like, and the tip of the plasticizing cylinder of the main injection device is connected via a first rotary shut-off valve. The tip of the plasticizing cylinder of the sub-injection device communicates with the outer nozzle through the second rotary shutoff valve. A nozzle body is constituted by the inner nozzle and the outer nozzle. Therefore, the first and second rotary shut-off valves are closed, the screws of the main and auxiliary injection devices are rotated and plasticized by a predetermined amount, and the second rotary shut-off valve is opened and the sub injection devices are opened. When the molten resin for skin layer molding is injected into the mold cavity, and then the first rotary shutoff valve is opened and the molten resin for core layer molding is injected from the main injection device, a sandwich molded product can be obtained. it can.

Japanese Patent Laid-Open No. 2001-170982 JP 2004-330600 A JP 2003-62864 A JP 2008-62595 A

  As the shut-off valve as described above, a rotary shut-off valve including a rotor that opens or closes a nozzle hole is known as well as a shut-off valve including a needle valve that opens and closes a nozzle hole of an injection nozzle. The above-described injection molding machine shown in FIG. 3 includes a rotary shutoff valve 60. The rotary shutoff valve 60 includes an injection nozzle 53 that also serves as a rotor casing, and a cylindrical rotor 61 that is driven to rotate or swing in close contact with the inner peripheral surface of the valve bore of the injection nozzle 53. It is composed of A molten resin passage is formed in the injection nozzle 63 in the axial direction. On the other hand, as shown in FIG. 3A, a resin passage 62 is also formed in the rotor 61 in the diameter direction. Therefore, when the rotor 61 is rotationally driven to a predetermined position, the molten resin passage of the injection nozzle 53 and the resin passage 62 of the rotor 61 are aligned, and the measuring chamber 55 of the plasticizing cylinder 50 and the injection nozzle 53 communicate with each other. When it becomes ready for injection and is driven to rotate by a predetermined amount, the alignment state is broken and communication is cut off. The nasal sagging is prevented by blocking. In such a cylindrical rotor 61, the outer peripheral portions of both ends of the rotor 61 are also shown in Patent Document 4 so that the molten resin does not leak from the rotor casing 53 to the outside, that is, from the bore of the injection nozzle 53 to the outside. As shown, the labyrinths 63 and 63 are processed over a predetermined width.

  As shown in FIG. 3A, shafts 64 and 64 are provided at both ends of the rotor 61 thus configured. These shafts 64, 64 are attached to the outside from the side of the injection nozzle 53. Then, the protruding portion is attached to a bifurcated ring bracket 65 (65). The bracket 65, and thus the rotor 61 attached to the bracket 65, is oscillatingly driven by the linear motion of the piston cylinder unit 66.

  As described above, a rotary shutoff valve is provided in an injection molding machine for molding a general molded article, a foam molded article, and an injection molding machine for a sandwich molded article. Therefore, it is possible to mold a molded product according to the purpose. Moreover, since the labyrinths 63 and 63 are relatively easy to process, an advantage that an injection molding machine can be provided at low cost is recognized. However, since there is a frictional sliding mechanism between the inner peripheral surface of the injection nozzle 53 and the outer peripheral surface of the processed portion of the labyrinth 63, 63 of the rotor 61, the interval or gap between these members is Since the structure is not fixed and adjustable, the gap becomes large when worn, and high-pressure molten resin may leak from the rotor casing or the injection nozzle 53 to the outside. In particular, when the rotary shut-off valve is driven to shut it, the pressure increases and may leak. A rotary shutoff valve provided with a piston ring in place of the labyrinths 63, 63 is also known, but the same can be said for this piston ring.

  Accordingly, an object of the present invention is to provide a rotary shut-off valve for an injection molding machine that has solved the above-described conventional problems or problems, and specifically, there is little wear between the rotor and the rotor casing. It is another object of the present invention to provide a rotary shut-off valve for an injection molding machine that can also adjust the clearance, in other words, adjust the adhesion between the rotor and the rotor casing.

  In order to achieve the above object, the present invention provides a rotor bearing device in which a cylindrical bearing ring, and a gap having a substantially wedge-shaped cross section in contact with the inner peripheral surface of the bearing ring and the outer peripheral surface of the tapered portion of the rotor are provided. The adjustment ring and the gap adjustment ring are configured by an adjustment nut that pushes the bearing ring and a predetermined position between the tapered portion of the rotor.

  That is, in order to achieve the above-mentioned object, the invention according to claim 1 is oscillated and rotationally driven by a bearing by a rotor casing and bearing devices provided at both ends of the valve bore of the rotor casing. The valve bore has a molding material inlet port communicating with the heating cylinder and a molding material outlet port communicating with the injection nozzle, and the rotor is driven to the first position. When the molding material passage hole formed in the rotor communicates with the inlet port and the outlet port and is driven to the second position, the communication state between the inlet port and the outlet port is blocked. In the rotary shut-off valve, the bearing device includes a cylindrical bearing ring mounted on each end of the valve bore, and an inner periphery of the bearing ring. And a gap adjusting ring having a substantially wedge-shaped cross section provided so as to be in contact with the outer peripheral surface of the tapered portion of the rotor, and the gap adjusting ring at a predetermined position between the bearing ring and the tapered portion of the rotor And when the clearance adjustment ring is pushed to a predetermined position by the adjustment nut, the clearance or the degree of adhesion between the bearing ring and the clearance adjustment ring and the taper portion of the clearance adjustment ring and the rotor It is comprised so that the clearance gap or contact | adhesion degree may be adjusted to a predetermined value.

  According to a second aspect of the present invention, in the shutoff valve according to the first aspect, the bearing ring is made of a metal in which a solid lubricant is embedded, and the third aspect of the invention is the first or second aspect of the invention. 3. The shutoff valve according to claim 2, wherein a third port is opened in the valve bore in addition to the molding material inlet port and the molding material outlet port, and is formed in the rotor when the rotor is driven to a predetermined position. When the molding material passage hole formed is in communication with any two of the molding material inlet port, the molding material outlet port, and the third port and is driven to another predetermined position, the inlet port The outlet port and the third port are configured such that their communication state is blocked.

As described above, according to the present invention, the molding material inlet port communicating with the heating cylinder and the molding material outlet port communicating with the injection nozzle are opened in the valve bore, and the rotor is driven to the first position. Then, the molding material passage hole formed in the rotor communicates with the inlet port and the outlet port, and when driven to the second position, the communication state between the inlet port and the outlet port is blocked. Therefore, the molding material can be injected from the injection nozzle and molded. It is also possible to prevent the molding material in the heating cylinder from inadvertently leaking from the injection nozzle.
According to the present invention, the bearing device for bearing the rotor includes a cylindrical bearing ring mounted on each end of the valve bore, an inner peripheral surface of the bearing ring, and an outer peripheral surface of the tapered portion of the rotor. Since the cross-sectional shape provided so as to be in contact with each other is constituted by a substantially wedge-shaped gap adjusting ring, and an adjusting nut for pushing the gap adjusting ring to a predetermined position between the bearing ring and the tapered portion of the rotor. The clearance adjustment degree between the bearing ring and the clearance adjustment ring, and the clearance or contact between the clearance adjustment ring and the taper portion of the rotor, simply by pushing the clearance adjustment ring to a predetermined position by the adjustment nut. The effect that the degree can be adjusted is obtained. That is, an effect peculiar to the present invention can be obtained in which the gap or the degree of adhesion as described above can be easily adjusted according to the degree of wear of the bearing device and according to the pressure or viscosity of the molding material.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows embodiment of this invention, The (a) is a front view which shows a principal part with a partial cross section, The (a) is the enlarged view seen in the line (a)-(a) direction in (a) It is sectional drawing. FIG. 2B is a detailed cross-sectional view showing, in an enlarged manner, a portion surrounded by a dotted line in FIG. 1A showing the embodiment of the present invention. It is a figure which shows the conventional injection molding machine, The (a) is a front view which shows the principal part in a partial cross section, The (a) is a perspective view which expands and shows the rotor of a rotary type shut-off valve.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. The injection molding machine 1 includes a heating cylinder 2 as is conventionally known. An injection nozzle 3 is attached to the front of the heating cylinder 2 via a cylinder block 10. A plurality of band heaters 4, 4,... Are individually provided on the outer peripheral portions of the heating cylinder 2, the cylinder block 10, and the injection nozzle 3. A cylinder bore 5 is formed in the axial direction inside the heating cylinder 2. The cylinder bore 5 communicates with the molding material passage 6 in the cylinder block 10 and communicates with the molding material passage 7 in the injection nozzle 3 as necessary. As is well known, the bore 5 of the heating cylinder 2 is provided with a screw 8 that is driven in the rotational direction and the axial direction. A screw head is attached to the tip of the screw 8, and the inside of the bore 5 of the heating cylinder 2 in front of the screw head is a measuring chamber 9.

  A rotary shutoff valve 20 is provided in the cylinder block 10 configured as described above. The rotary shutoff valve 20 includes a rotor casing and a rotor 22 that is driven to rotate or swing in a valve bore 21 of the casing. In the illustrated embodiment, the cylinder block 10 is a rotor casing 11. As described above, the molding material passage 6 is formed in the rotor casing 11 in the axial direction. The passage 6 is interrupted by the valve bore 21 and is connected to the right heating cylinder 2 in FIG. The part connected to the molding material inlet port and the part connected to the left injection nozzle 3 are the molding material outlet port. These inlet and outlet ports are interrupted by the valve bore 21 but are aligned in the axial direction.

  The rotor 22 that is in fluid-tight contact with the inner peripheral wall of the valve bore 21 of the rotor casing 11 and is rotationally driven is substantially cylindrical as shown in FIG. ing. A molding material passage hole 23 in which a molten molding material flows in the diameter direction is formed at a substantially central portion in the axial direction of the rotor 22. The molding material passage hole 23 is aligned with the molding material inlet port and the molding material outlet port of the rotor casing 11 during injection filling.

  Since the rotor 22 is symmetric as shown in FIG. 1A, only one structure will be described below. The rotor 22 is reduced in diameter in a step shape at a position close to the end direction by a predetermined distance from the molding material passage hole 23, and further reduced in a taper shape toward the end. The tapered portion is a tapered portion 24 or a passive cam portion. As shown in the enlarged view of FIG. 2, the adjustment shaft portion 25 having a diameter reduced stepwise and the mounting shaft portion 28 having a diameter further reduced than the adjustment shaft portion 25, from the terminal portion of the taper portion 24. Are integrally extended. An adjustment screw 26 to which the adjustment nut 27 is screwed is formed on the adjustment shaft portion 25, and a tightening screw 29 to which the attachment nut 39 is screwed is formed at the end of the attachment shaft portion 28.

  A bearing ring 30 made of an oilless metal having a predetermined length, for example, a metal in which a solid lubricant is embedded, is fitted into the inner peripheral surfaces of both end portions of the valve bore 21. Between the inner peripheral surface of the bearing ring 30 and the outer peripheral surface of the tapered portion 24, a gap adjusting ring 31 made of a thin and highly malleable metal such as titanium copper for springs is provided. The gap adjusting ring 31 is shorter than the bearing ring 30 in the axial direction, and the outer diameter is constant in the axial direction, but the inner diameter increases in a tapered shape toward the molding material passage hole 23. That is, as shown in FIG. 2, the cross-sectional shape is substantially wedge-shaped and constitutes an active cam portion. Therefore, when the active cam portion, that is, the gap adjusting ring 31 is pushed in the direction of the molding material passage hole 23, the gap between the bearing ring 30 and the gap adjusting ring 31 and the gap between the gap adjusting ring 31 and the tapered portion 24 are as follows. Narrows or increases adhesion. As the push member, an adjustment nut 27 is provided in the present embodiment. The adjustment nut 27 is screwed into the adjustment screw 26 and pushes the thick portion of the gap adjustment ring 31.

  In the present embodiment, for driving the rotor 22 of the rotary shutoff valve 20 configured as described above, as shown in FIG. 1A, an actuator 35 composed of, for example, a piston cylinder unit is used. Applied. The piston rod of the actuator 35 is connected to the link brackets 36 and 37 in a conventionally known manner. The link bracket 37 is bifurcated and inserted into the mounting shaft portions 28 and 28 so that the end portions of the link bracket 37 sandwich the both end portions of the rotor 22, and are attached by mounting nuts 39 through washers 38 and 38. . When the piston rod of the actuator 35 reciprocates linearly, the rotor 22 swings and swings to take the first and second different positions, as will be described in the next section. .

  Next, the operation of the above embodiment will be described. The rotor 22 is inserted into a predetermined position in the valve bore 21 of the cylinder block 10, that is, the rotor casing 11. Then, the bearing ring 30 is inserted from the end until it abuts on a step formed in the valve bore 21. Next, the gap adjusting ring 31 is inserted from the thinner side between the bearing ring 30 and the passive cam portion 24 of the rotor 22. Then, the gap adjusting ring 31 is pushed toward the center by the adjusting nut 27 to a desired position. At this time, clearances s and S are provided between the front end portion of the clearance adjustment ring 31 and the body portion 22 ′ of the rotor 22 and between the adjustment nut 27 and the rear end portion of the passive cam portion 24. Therefore, it can be pushed to a desired position. When pushed in, due to the wedge action of the gap adjusting ring 31, the bearing ring 30 and the gap adjusting ring 31 and the gap adjusting ring 31 and the taper portion 24 are brought into close contact with each other with a predetermined force. Thereby, the leakage of the molding material from the bearing vicinity of the rotor 22 is prevented. The bearing of the rotor 22 with respect to the rotor casing 11 is mainly performed between the inner peripheral surface of the bearing ring 30 and the outer peripheral surface of the gap adjusting ring 31. The bifurcated link bracket 37 (37) is attached to the attachment shaft portions 28, 28 as described above, and the assembly is completed.

  The rotor 22 of the rotary shutoff valve 20 is rotationally driven by an actuator 35 so that the molding material passage hole 23 of the rotor 22 is in a closing position or a plasticizing position where it is removed from the molding material inlet port and the outlet port of the rotor casing 11. A pellet-shaped resin material is supplied to the heating cylinder 2 while rotating the screw 8. The resin material is melted by heat generated by frictional force, shearing force, etc. due to the rotation of the screw 8 and heat applied from the band heaters 4, 4,. Is done. The screw 8 is retracted by the pressure of the accumulated molding material. Or suck back. Plasticization ends when a predetermined amount is weighed.

  The molding material passage hole 23 of the rotor 22 is driven to an injection position communicating with the molding material inlet port and the molding material outlet port of the rotor casing 11. The screw 8 is driven in the axial direction and injected into a mold cavity (not shown). Wait for cooling to solidify and open the mold. Thereby, a molded article is obtained. Thereafter, molding is performed in the same manner. As described in the background art section, foamed molded products, sandwich molded products, and the like are molded.

  If necessary, as described above, the adjustment nut 27 pushes the gap adjustment ring 31 toward the center to a desired position, and between the gap adjustment ring 31 and the bearing ring 30 and between the gap adjustment ring 31 and the rotor 22. The degree of adhesion or gap between the taper portion, that is, the passive cam portion 24 is adjusted.

  The present invention is a three-way rotary shut-off as described in, for example, Japanese Patent Application Laid-Open Nos. 2001-162650 and 2001-162660 other than the two-way rotary shut-off valve as described above. It is clear that the same applies to the valve as it is.

DESCRIPTION OF SYMBOLS 1 Injection molding machine 2 Heating cylinder 3 Injection nozzle 6 Molding material passage 7 Molding material passage 8 Screw 10 Cylinder block 11 Rotor casing 20 Rotary shutoff valve 22 Rotor 23 Molding material passage hole 24 Passive cam part (taper part)
27 Adjustment nut 30 Bearing ring 31 Clearance adjustment ring

Claims (3)

A molding material comprising a valve casing and a rotor which is supported by bearing devices provided at both ends of the valve bore of the valve casing and is rotationally driven to rotate. The molding material communicated with the heating cylinder in the valve bore When the inlet port and the molding material outlet port communicating with the injection nozzle are opened and the rotor is driven to the first position, the molding material passage hole formed in the rotor becomes the inlet port and the outlet. A rotary shutoff valve configured to block communication between the inlet port and the outlet port when communicated with the port and driven to the second position;
The bearing device includes a cylindrical bearing ring mounted on each end of the valve bore, a cross section provided in contact with an inner peripheral surface of the bearing ring and an outer peripheral surface of the tapered portion of the rotor. A gap adjusting ring having a substantially wedge shape, and an adjusting nut for pushing the gap adjusting ring to a predetermined position between the bearing ring and the tapered portion of the rotor;
When the clearance adjustment ring is pushed to a predetermined position by the adjustment nut, the clearance or adhesion between the bearing ring and the clearance adjustment ring and the clearance or adhesion between the clearance adjustment ring and the tapered portion of the rotor are increased. A rotary shutoff valve for an injection molding machine, wherein the rotary shutoff valve is adjusted to a predetermined value. 2. The rotary shut-off valve for an injection molding machine according to claim 1, wherein the bearing ring is made of a metal embedded with a solid lubricant. The shutoff valve according to claim 1 or 2, wherein a third port is opened in the valve bore in addition to the molding material inlet port and the molding material outlet port, and the rotor is driven to a predetermined position. When the molding material passage hole formed in the rotor communicates with any two ports of the molding material inlet port, the molding material outlet port, and the third port, and is driven to another predetermined position. The rotary shut-off valve for an injection molding machine, wherein the inlet port, the outlet port, and the third port are configured to be disconnected from each other.

Images