The disclosure relates to injection molding machines, and to components and layout for a two-platen hybrid injection molding machine.
U.S. Pat. No. 7,449,139 (Kestle) purports to disclose a molding-system platen actuator. The molding-system platen actuator includes a platen-stroke actuator. The platen-stroke actuator includes an electrical actuator, and a guide bushing connected with the electrical actuator. The molding-system platen actuator further includes a mold-break actuator in-line with the platen-stroke actuator. The mold-break actuator includes: a hydraulic actuator having a piston that is strokable along an in-line housing, and air pressure that is generatable between the piston and the guide bushing. The air pressure is useable to push the piston backwardly.
U.S. Pat. No. 6,322,343 (Yoda et al.) purports to disclose a compact injection molding machine with casters. An injection unit and a mold clamping unit in the compact injection molding machine are disposed longitudinally on a base cabinet which is formed of a tall cabinet with a rectangular top surface. The molding machine can be manually moved and installed by mounting the casters on the bottom of the base cabinet. The inside of the base cabinet is partitioned with partition plates and receives units and devices required for the injection molding of resin. The injection unit and mold clamping unit may use any of oil pressure and electric power as their driving source. In the case of oil pressure, a hydraulic driving circuit and the like are received in the base cabinet, and in the case of electric power, electric servomotors and the like are received in the base cabinet. Further, the operation side of the top surface of base cabinet can be formed into a work table, by disposing the injection unit and mold clamping unit longitudinally offset toward the counter-operation side on the top surface of base cabinet.
U.S. Pat. No. 5,756,019 (Nakazawa et al.) purports to disclose an injection pressure is detected as a pressure detection value Dp during injection and filling, and the thus obtained pressure detection value Dp is multiplied by a preset predetermined coefficient so as to be converted into a desired mold clamping force Fc with which the mold clamping force is controlled. The desired mold clamping force Fc is set to a minimum value which a mold does not open, that is, the desired mold clamping force Fc is calculated with the use of Fc=(α*S*β)Dp, where α is a charging rate of resin in a mold cavity, S is an entire projected area of a molding article, β is a safety factor, and Dp is a pressure detection value Dp. With this arrangement, in a section where the injection pressure gradually increases from zero during injection and filling, the profile (variation curve) of mold clamping force gradually increases as the injection pressure varies. At this stage, the mold clamping force during injection and filling is set to a minimum value with which the mold does not open so that the power consumption can be minimized.
The following summary is intended to introduce the reader to various aspects of the applicant's teaching, but not to define any invention. In general, disclosed herein are one or more methods or apparatuses related to injection molding.
According to some aspects of the teaching disclosed herein, an injection molding machine comprises a machine base, and a stationary platen and a moving platen supported by the base. Each platen supports a respective stationary and moving mold half for forming a mold between the platens. An electrically driven platen actuator is coupled to the moving platen for advancing and retracting the moving platen between mold-closed and mold-open positions. At least one hydraulic clamp actuator is coupled to the platens for clamping together the stationary and moving platens when the moving platen is in the mold-closed position. An injection unit is supported by the base and includes a plasticizing screw for plasticizing an injection material. A hydraulically powered rotary injection drive is coupled to the plasticizing screw for rotating the screw, and a hydraulic injection actuator is coupled to the plasticizing screw for injecting the injection material into the mold. An ejector is coupled to the moving platen. An electrically driven ejector actuator is coupled to the ejector for moving the ejector between advanced and retracted positions for ejecting molded articles from the moving mold half when the moving platen is in the mold-open position.
The injection molding machine may further comprise a plurality of tie bars generally extending between the stationary and moving platens. Each of the at least one hydraulic clamp actuators may comprise a piston affixed to a respective tie bar and slidable within a respective cylinder housing. Each cylinder housing may provide a clamp chamber and an unclamp chamber on opposite sides of the respective piston.
The platen actuator may comprise a first ball screw driven by a first motor. The ejector actuator may comprise a second ball screw driven by a second motor.
The base may comprise an injection unit support portion beneath the injection unit and a platen support portion beneath the platens. The injection unit support portion of the base may house an electrical cabinet, a pump cabinet, and a hydraulic tank disposed laterally intermediate the pump cabinet and the electrical cabinet.
The injection unit support portion may be generally bounded laterally by an axially extending front wall and an axially extending back wall. The injection support portion may be generally bounded axially by a laterally extending inner wall adjacent the platen support portion, and a laterally extending outer wall spaced apart from the inner wall. The tank may have a tank length that extends from laterally extending inner and outer tank walls that are axially intermediate the inner and outer walls of the injection unit support portion.
The tank may have a tank width that extends laterally between a first sidewall and a second sidewall. The first sidewall may be generally parallel to, and laterally intermediate, the front and back walls of the injection unit support portion of the base and run axially between the inner and outer lateral walls. The second sidewall may generally be parallel to the first sidewall, and laterally intermediate the first sidewall and the back wall of the injection unit support portion.
The electrical cabinet may be disposed in the injection unit support portion of the base, generally between the front wall and the first sidewall. The pump cabinet may be disposed in the injection unit support portion of the base, generally between the second sidewall and the back wall.
The base may have a base width extending laterally between the front and back walls. The base width may be between about 3 times and about 10 times greater than the tank width. The tank length may be between about 2 times and about 10 times greater than the tank width.
According to other aspects of the teaching disclosed herein, an injection molding machine comprises a base extending lengthwise along a machine axis. The base has a platen support portion extending along a first axial portion of the base, and an injection unit support portion extending along a second axial portion of the base. A pair of platens may be supported by the platen support portion of the base for carrying respective mold halves of a mold. An injection unit may be supported by the injection unit support portion of the base for injecting melt into the mold. The injection unit support portion of the base houses an electrical cabinet, a pump cabinet, and a hydraulic tank disposed laterally intermediate the pump cabinet and the electrical cabinet.
The injection unit support portion may be generally bounded laterally by an axially extending front wall and an axially extending back wall. The injection support portion may be generally bounded axially by a laterally extending inner wall adjacent the platen support portion, and a laterally extending outer wall spaced apart from the inner wall. The tank may have a tank length that extends from laterally extending inner and outer tank walls that are axially intermediate the inner and outer walls of the injection unit support portion.
The tank may have a tank width that extends laterally between a first sidewall and a second sidewall. The first sidewall may be generally parallel to, and laterally intermediate, the front and back walls of the injection unit support portion of the base. The second sidewall may be generally parallel to the first sidewall, and laterally intermediate the first sidewall and the back wall of the injection unit support portion.
The pump cabinet may be disposed in the injection unit support portion of the base, generally between the front wall and the first sidewall. The electrical cabinet may be disposed in the injection unit support portion of the base, generally between the second sidewall and the back wall.
The electrical cabinet may be disposed in the injection unit support portion of the base, generally between the front wall and the first sidewall. The pump cabinet may be disposed in the injection unit support portion of the base, generally between the second sidewall and the back wall.
The base may have a base width extending laterally between the front and back walls, and the base width may be between about 3 times and about 10 times greater than the tank width. The tank length may be between about 2 times and about 10 times greater than the tank width.
One of the platens may be a moving platen, and the machine may further comprise an electrically driven platen actuator coupled to the moving platen for advancing and retracting the moving platen between mold-closed and mold-open positions. The platen actuator may comprise a first ball screw driven by a first motor.
The machine may further comprise at least one hydraulic clamp actuator coupled to the platens for clamping together the platens when the platens are in a mold-closed position. The injection molding machine may further comprise a plurality of tie bars generally extending between the platens. Each of the at least one hydraulic clamp actuators may comprise a piston affixed to a respective tie bar and slidable within a respective cylinder housing. Each cylinder housing provides a clamp chamber and an unclamp chamber on opposite sides of the respective piston.
The machine may further comprise an injection unit supported by the base. The injection unit may include a plasticizing screw for plasticizing an injection material. A hydraulically powered rotary injection drive may be coupled to the plasticizing screw for rotating the screw. A hydraulic injection actuator may be coupled to the plasticizing screw for injecting the injection material into the mold.
The machine may further comprise an ejector coupled to the moving platen. An electrically driven ejector actuator may be coupled to the ejector for moving the ejector between advanced and retracted positions for ejecting molded articles from one of the mold halves when the platens are in the mold-open position. The ejector actuator may comprise a second ball screw driven by a second motor.
Other aspects and features of the present specification will become apparent, to those ordinarily skilled in the art, upon review of the following description of the specific examples of the specification.
The drawings included herewith are for illustrating various examples of articles, methods, and apparatuses of the teaching of the present specification and are not intended to limit the scope of what is taught in any way. In the drawings:
Various apparatuses or processes will be described below to provide an example of an embodiment of each claimed invention. No embodiment described below limits any claimed invention and any claimed invention may cover processes or apparatuses that differ from those described below. The claimed inventions are not limited to apparatuses or processes having all of the features of any one apparatus or process described below or to features common to multiple or all of the apparatuses described below. It is possible that an apparatus or process described below is not an embodiment of any claimed invention. Any invention disclosed in an apparatus or process described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors or owners do not intend to abandon, disclaim or dedicate to the public any such invention by its disclosure in this document.
Referring to
The moving platen 106 may be slidably supported on at least one rail of the injection molding machine 100 by at least one runner. In the example shown, the moving platen 106 is slidably supported on a pair of rails 110 by a pair of runners 112, and is movable along the rails 110 between mold-open and mold-closed position. In the example illustrated, as the moving platen 106 moves along the rails 110 between the mold open and closed positions, it moves relative to the machine tie bars 108. In other examples, the tie bars can be fixed to, and moveable with, the moving platen.
Referring to
Referring to
With reference again to
When in the locked position, the first and second teeth 86, 90 are oriented to be in circumferential registration with each other, so that the first and second teeth inter-engage, thereby inhibiting relative axial motion between the moving platen 106 and tie bar 108. The lock nut 82 can be rotated relative to the tie bar 108 to an unlocked position (
An electrical lock actuator 94 may be provided for moving the locking devices between the locked and unlocked position. In the example illustrated, the lock actuator comprises an electric lock motor 96 coupled to a linkage assembly 98. Energizing the lock motor 96 selectively moves one of the linkage arms (the top, generally horizontal arm in
Before moving the locking device 80 from the unlocked to the locked position, the tie bar 108 can be moved axially relative to the lock nut 82 to any one of a plurality of meshing positions in which the peaks of one set of teeth are in axial registration with the valleys between axially adjacent ones of the other set of teeth. Adjacent meshing positions are spaced apart axially by an amount generally equal to the pitch of the teeth. Providing a plurality of meshing positions can facilitate accommodating molds with different axial extents (different mold heights).
Referring to
Referring now to
A hydraulically powered rotary injection drive 144 is coupled to the plasticizing screw 142 for rotating the screw 142. In the example shown, the hydraulically powered rotary injection drive 144 includes a hydraulic motor 150 that drives rotation of a rotary spline shaft 148. Rotation of the rotary spline shaft 148 causes a corresponding rotation of a piston 146 that has an inner bore slidably coupled, but rotationally locked, with the outer surface of the spline shaft. A back end of the screw 142 is fixed to the piston, so that rotation of a piston 146 causes a corresponding rotation of the plasticizing screw 142.
A hydraulic injection actuator 152 is coupled to the plasticizing screw 142 for injecting the injection material into the mold. In the example shown, the hydraulic injection actuator comprises the piston 146. The piston 146 includes a piston head 154, and an interior volume of the housing 136 includes a first (advance) pressure chamber 156 on a first side of a piston head 154 and a second (retract) pressure chamber 158 on a second side of the piston head 154. The first pressure chamber 156, when pressurized with hydraulic fluid, urges the piston 146 to slide along the rotary spline shaft 148 towards an advanced position (i.e. towards the nozzle 140). The second pressure chamber 158, when pressurized with hydraulic fluid, urges the piston 146 to slide along the rotary spline shaft 148 towards a retracted position (i.e. away from the nozzle). Sliding of the piston 146 towards the advanced position causes a corresponding sliding of the plasticizing screw 142, which causes injection of the injection material in to the mold.
Referring back to
Referring also to
In the example shown, the electrically driven ejector actuator 162 includes a second ball screw 171 driven by a second motor 170. The second motor 170 is fixed relative to the moving platen and coupled to the second ball screw by a belt 172. The shaft of the ball screw is fixed to the support plate 164, and a ball nut 173 is fixed to the carrier plate 166. A plurality of rods 174 are mounted between the support plate 164 and the carrier plate 166 to help guide the axial movement of the carrier plate 166 between the advanced and retracted positions. The second motor 170 is, in the example illustrated, mounted to the lower portion of the support plate 164, and is disposed axially forward of the support plate 164 (i.e. extending axially beneath the carrier plate 166 and moving platen 106).
Referring now to
Referring to
In the example illustrated, the hydraulic tank 188 is disposed adjacent the support wall 192. At least a portion of the support wall 192 can provide a first sidewall 192a of the tank 188. This can facilitate positioning the hydraulic tank 188 laterally intermediate the front and back cabinets.
The tank 188 can have a second sidewall 194 generally parallel to, and spaced away from, the first sidewall 192a. The second sidewall 194 can extend lengthwise along the injection unit support portion 109 from an outer end edge proximate the outer end wall 182, to an inner end edge spaced away from the outer wall 182 towards the inner wall 180. The inner end edge of the second sidewall 194 can be proximate to, and/or secured to, the inner wall 180.
Referring still to
Referring still to
Referring still to
In the illustrated example, the front cabinet 184 is a pump cabinet and the back cabinet 186 is an electrical cabinet. A pressurized oil delivery system including, for example, a pump unit 185 is housed within the pump cabinet 184. Hydraulic services 193 can be collectively mounted to the outer wall 182 of the base 102. An electrical system is housed within the electrical cabinet, the electrical system including, for example, power supply connections and I/O racks.
Furthermore, in the example illustrated, the platen support portion 107 of the machine generally forms an “electric” side of the machine having electrically driven actuators and drives. The injection unit support portion 109 generally forms a “hydraulic” side of the machine, having hydraulically driven actuators and drives.
In use, the platen actuator 114 can be electrically energized to advance the moving platen 106 towards a closed position relative to the stationary platen 104. In the example illustrated, the moving platen is moved by the platen actuator 114 to a meshing position in which the mold halves supported by the platens may be spaced slightly apart or may be touching each other. When the platen is in the meshing position, the lock nut teeth 86 are axially aligned with, and can be rotated into, the first circumferential valleys between the tie bar teeth 90. In the example illustrated, the lock actuator is electrically energized to move the lock nut 82 to the locked position.
Once the locking devices 80 have been moved to the locked position, the clamp chamber 126 can be pressurized (hydraulically) so as to exert a clamping force urging the mold halves tightly together. The piston 124 would be urged in the clamping direction (i.e. to the right as shown in
In the example illustrated, the hydraulic pump unit 185 comprises a pump 185a driven by a single servo motor 185b for supplying a flow rate of oil from the pump 185a to the hydraulic clamp actuators 120, hydraulic rotary injection drive 144, and hydraulic axial injection actuator 152, in an on-demand, as-needed basis. This configuration can reduce the need for separately controllable servo-valves at each of the hydraulically powered actuators or drives. In some examples, more than one servo-motor and pump may be provided.
After the molded article has hardened sufficiently, the pressure in the clamp chamber 126 can be relieved and the unclamp chamber 128 can be pressurized so as to exert a mold break force urging the mold halves apart and moving the piston 124 to the unclamped position. The locking devices 80 can be moved to the unlocked position so as to unlock the moving platen 106 from the tie bars 108. The platen actuator 114 can then be energized to retract the moving platen 106 to an open position spaced away from the stationary platen 104. The ejector actuator 160 can be energized to facilitate ejection of the molded article from the mold.
Referring now to
As shown in
The injection unit support portion 209 houses a front cabinet 284, a back cabinet 286, and a hydraulic tank 288.
With reference to
The tank 288 also has a tank width 291 that extends laterally between a first sidewall 292a and a second sidewall 294. The first sidewall 292a is generally parallel to and laterally intermediate the front 276 and back 278 walls. The second sidewall 294 is generally parallel to the first sidewall 292a, and in the example illustrated is laterally intermediate the first sidewall 292a and the back wall 278 of the injection unit support portion 209.
In the illustrated example, the vertical support wall 292 extends generally from the outer wall 282 to the inner wall 280, and the second sidewall 294 extends generally from the inner tank wall 281 to the inner tank wall 281. The first sidewall 292a of the tank comprises a portion of the vertical support wall 292.
The base 202 has a base width 296 extending laterally between the front 276 and back walls 278. In the example illustrated, the base width 296 is approximately 5 times greater than the tank width 291. Furthermore, the tank length 290 may be between about 2 and about 10 times greater than the tank width 291. In the example illustrated, the tank length 290 is approximately 4 times greater than the tank width 291.
Referring still to
In the illustrated example, the front cabinet 284 is an electrical cabinet and the back cabinet 286 is a pump cabinet. As shown in
While the above description provides examples of one or more processes or apparatuses, it will be appreciated that other processes or apparatuses may be within the scope of the accompanying claims.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/639,307 filed on Apr. 27, 2012, the entire contents of which are hereby incorporated by reference herein.
Number | Date | Country | |
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61639307 | Apr 2012 | US |