Sequential injection of multiple mold cavities

Abstract

An injection molding apparatus (10a) includes: one or more first downstream channels (166, 166a, 166b) and associated first gates (34, 34a, 34b); and one or more second downstream channels (168, 168a, 168b) and associated second gates (32, 32a, 32b). The one or more first downstream channels (166, 166a, 166b) and first gates (34, 34a, 34b) deliver injection fluid (18) to a first cavity (300a) of a mold system (302, 303). The one or more second downstream channels (168, 168a, 168b) and second gates (32, 32a, 32b) deliver injection fluid to a second cavity (300b) of the mold system (302, 303). The mold system selects... The device, clamped together under constant force, includes a first upstream valve (118) and a second upstream valve (108), the first upstream valve (118) initiating and preventing the injection fluid from flowing to the first gate (34, 34a, 34b), and the second upstream valve (108) initiating and preventing the injection fluid from flowing to one or more second gates (32, 32a, 32b). The device includes a control system (20) adapted to open or initiate the injection fluid (18) to flow to one or more first gates (34, 34a, 34b) at a first selected time, and further instructing the second upstream valve (108) to open or initiate the injection fluid (18) to flow to one or more second gates (32, 32a, 32b) at a second selected time, wherein the second selected time is delayed relative to the first selected time during the injection cycle.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Application 62 / 978,928, filed February 20, 2020, the disclosure of which is incorporated herein by reference in its entirety, as if fully set forth herein.

[0003] All of the following disclosures are incorporated herein by reference in their entirety, as if fully set forth herein: U.S. Patent 5,894,025, U.S. Patent 6,062,840, U.S. Patent 6,294,122 (7018), U.S. Patent 6,309,208, U.S. Patent 6,287,107, U.S. Patent 6,343,921, U.S. Patent 6,343,922, U.S. Patent 6,254,377, U.S. Patent 6,261,075, U.S. Patent 6,361,300 (7006), U.S. Patent 6,419,870, U.S. Patent 6,464,909 (7031), U.S. Patent 6,062,840 (7052), U.S. Patent 6,261,075 (…). U.S. Patent No. 7052 (US1), U.S. Patent No. 6,599,116, U.S. Patent No. 7,234,929 (US1), U.S. Patent No. 7,419,625 (US2), U.S. Patent No. 7,569,169 (US3), U.S. Patent No. 8,297,836 (US3), U.S. Patent Application No. 10 / 214,118 (US3), filed August 8, 2002, U.S. Patent Application No. 10 / 214,118 (US3), filed August 8, 2002, U.S. Patent Application No. 7,029,268 (US1), U.S. Patent No. 7,270,537 (US2), U.S. Patent No. 7,597,828 (US3), U.S. Patent Application No. 09 / 699,856, filed October 30, 2000. (7056), U.S. Patent Application 10 / 269,927 (7031), filed October 11, 2002; U.S. Application 09 / 503,832 (7053), filed February 15, 2000; U.S. Application 09 / 656,846 (7060), filed September 7, 2000; U.S. Application 10 / 006,504 (7068), filed December 3, 2001; U.S. Application 10 / 101,278 (7070), filed March 19, 2002; and PCT Applications PCT / US11 / 062099 (7100WO0) and PCT Applications PCT / US11 / 062096 (7100WO1), filed U.S. Patent 8,5 62,336, U.S. Patent 8,091,202 (7097 US1) and U.S. Patent 8,282,388 (7097 US2), U.S. Patent 9,724,861 (7129 US4), U.S. Patent 9,662,820 (7129 US3), International Publication WO2015006261 (7135 WO0), International Publication WO2014209857 (7134 WO0), International Publication WO2016153632 (7149 WO2), International Publication WO2016153704 (7149 WO4), U.S. Patent 9,205,587 (7117 US0), U.S. Application 15 / 432, filed February 14, 2017.175 (7117US2), US Patent 9144929 (7118US0), US Publication 20170341283 (7118US3), International Application WO2017214387 (7163WO0), International Application PCT / US17 / 043029 (7165WO0) filed July 20, 2017, International Application PCT / US17 / 043100 (7165WO1) filed July 20, 2017, and International Application PCT / US17 / 036542 (7163WO0) and International Application WO2018129015 (7118US2) filed June 8, 2017. 169WO0), International Application WO2018148407 (7170WO0), International Application WO2018183810 (7171WO), International Application WO2018175362, International Application WO2018194961 (7174WO0), International Application WO2018200660 (7176WO0), International Application WO2019013868 (7177), International Application WO2019100085 (7178WO0), International Application WO2020068285 (7182WO0), International Application WO2020176479 (7185WO0). Background Technology

[0004] Injection molding systems have been developed to simultaneously inject fluid flows into two or more mold cavities held or clamped by a single clamping device during the filling stage. Summary of the Invention

[0005] According to the present invention, an injection molding apparatus (10a) is provided, comprising an injection molding machine (500) that injects a selected fluid (18) into a distribution manifold (800), the distribution manifold (800) having a distribution channel (160) that generally guides the injected fluid (18) to: One or more first downstream channels (166, 166a, 166b) and associated first gates (34, 34a, 34b) deliver the injection fluid (18) to a first cavity (300a) of the mold system (302, 303), and One or more second downstream channels (168, 168a, 168b) and associated second gates (32, 32a, 32b) deliver the injected fluid to the second cavity (300b) of the mold system (302, 303). The mold system (302, 302) is clamped together by the clamping device (700) under a selected clamping force. The device includes a first upstream valve (118) and a second upstream valve (108), the first upstream valve (118) initiating and preventing the injection fluid from flowing from the distribution channel (160) to the first gate (34, 34a, 34b), and the second upstream valve (108) initiating and preventing the injection fluid from flowing from the distribution channel (160) to the one or more second gates (32, 32a, 32b). The device also includes a control system (20) adapted to instruct the first upstream valve (118) to open or activate the injection fluid (18) to flow to the one or more first gates (34, 34a, 34b) at a first selected time, and further instruct the second upstream valve (108) to open or activate the injection fluid (18) to flow to the one or more second gates (32, 32a, 32b) at a second selected time, wherein the second selected time is delayed, subsequent or continuous relative to the first selected time during the injection cycle.

[0006] In such a device, the second selected time is selected such that a first peak injection fluid force or pressure occurring in the first chamber (300a) during an injection cycle occurs at a first peak time, which cancels out a second peak time at which a second peak injection fluid force or pressure occurs in the second chamber (300b) during the injection cycle.

[0007] In such a device, the second selected time is selected such that the maximum cumulative fluid force or pressure occurring in the first and second chambers (300a, 300b) during the injection cycle is less than the accumulation of the first and second peak injection fluid force or pressure.

[0008] In such a device, the second selected time is selected such that the first holding phase injection fluid force or pressure occurring in the first chamber (300a) during the injection cycle occurs during the first holding phase time, which cancels out the second holding phase injection fluid force or pressure occurring in the second chamber (300b) during the injection cycle.

[0009] In such a device, the injection fluid (18) is first injected into the first and second cavities (300a, 300b) at a filling stage pressure or force and subsequently at a holding stage pressure or force, the filling stage pressure or force being substantially less than the holding stage pressure or force.

[0010] In such a device, the selected clamping force is typically selected to be at least equal to the cumulative peak force or pressure exerted by the injection fluid (18) within the first and second cavities (300a, 300b) during the injection cycle.

[0011] In such an apparatus, one or more first downstream valves (150b) control the delivery of the injection fluid (18) through the first downstream channels (166, 166a, 166b) and the associated first gates (34, 34a, 34b), and one or more second downstream valves (150a) control the delivery of the injection fluid (18) through the second downstream channels (168, 168a, 168b) and the associated second gates (32, 32a, 32b).

[0012] The second selected time is typically selected such that the time during which the injection fluid exerts peak force or pressure in the first cavity during the injection cycle substantially cancels out the time during which the injection fluid exerts peak force or pressure in the second cavity during the injection cycle.

[0013] The second selected time is typically selected such that the selected force of the clamping device is significantly reduced relative to the sum of the peak force or pressure exerted by the injected fluid (18) in the first and second cavities (300a, 300b), in which the injected fluid (18) is simultaneously delivered to the first downstream gate (34, 34a, 34b) and the second downstream gate (32, 32a, 32b).

[0014] In such a device, one or more of the first and second downstream valves (150a, 150b) typically include actuators (50, 50b) interconnected with valve pins (1041, 1041a) having control surfaces (755, 1155) having a selected configuration adapted to engage with selected complementary surfaces (765, 1254) of downstream channels (166, 168) such that the flow rate of the injected fluid (18) can be controlled by controlling the axial position of the control surfaces (755, 1155) of the valve pin relative to the selected complementary surfaces (765, 1254) of the downstream channels (166, 168).

[0015] In such a device, the controller (20) may include instructions that control the opening time of the upstream valves (108, 108s, 118, 118s) such that the upstream valves (108, 108s, 118, 118s) are controllably opened to allow fluid (18) to be delivered and filled into the mold cavity (300a, 300b) at different or staggered times during the injection cycle.

[0016] In such a device, the controller (20) may include instructions that control the degree of opening of the upstream valves (108, 108s, 118, 118s) at selected times during the injection cycle, such that the upstream valves are controllably opened to allow fluid (18) to be delivered and fill the mold cavity (300a, 300b) at different selected rates during the injection cycle.

[0017] The controller (20) may include an algorithm that receives fluid pressure data from one or more pressure sensors (60a, 80a) that measure fluid pressure at selected locations within an upstream distribution channel (162, 164).

[0018] The algorithm is included within the controller (20), which may include a memory and instructions, the memory storing a predetermined fluid pressure curve for the selected location, at which the sensor (60a, 80a) measures pressure, and the instructions instructing the upstream valve (108s, 118s) to open to a certain extent during the injection cycle, the opening degree of the upstream valve (108s, 118s) affecting the fluid pressure at the selected location, the fluid pressure matching the predetermined pressure curve during the injection cycle.

[0019] The controller (20) can be interconnected with one or more pressure sensors (80c), and the controller (20) receives fluid pressure data from the one or more pressure sensors (80c), which measure the fluid pressure in downstream fluid channels (166, 168) located upstream of and away from the gates (32, 34) at positions (166ua). The controller (20) includes a memory that stores information for the fluid pressure upstream of and away from the gates. The predetermined fluid pressure profile and instructions for the gate location (166ua), the instructions instructing the downstream actuators (50a, 50b) to axially position interconnected valve pins (1041, 1041), the valve pins (1041, 1041) having pin surfaces (755) adapted to interact with complementary channel surfaces (765) to influence the fluid pressure at locations upstream of and away from the gate (166ua), the fluid pressure matching the predetermined fluid pressure profiles for locations upstream of and away from the gate (166ua).

[0020] The controller (20) can receive fluid pressure data from one or more pressure sensors (60c) that measure fluid pressure at a location within cavities (300a, 300b), and a memory that stores a predetermined fluid pressure curve for the location where the pressure is measured by the one or more pressure sensors (60c). The memory also includes instructions that instruct downstream actuators (50a, 50b) to axially move valve pins (1041, 104). 1a), the valve pin (1041, 1041a) has a surface (1155) adapted to interact with a complementary gate surface (1254) to control the fluid pressure at the location where pressure is measured by one or more pressure sensors (60c), and the controller (20) includes instructions that instruct the actuator to move the valve pin (1041, 1041a) to a position such that the fluid pressure at the location of the pressure sensor (60c) matches the pressure of the predetermined curve.

[0021] The controller may include instructions that instruct the downstream actuators (50a, 50b) to control the sequence and timing of the injection fluid flow by controlling the axial position of the valve pins (1041, 1041a).

[0022] In another aspect of the invention, a method is provided for performing an injection cycle in an injection molding machine (500) including a distribution manifold (800), the method comprising: The injection fluid (18) is directed to: via the common distribution channel (160): One or more first downstream channels (166, 166a, 166b) and associated first gates (34, 34a, 34b) deliver the injection fluid (18) to a first cavity (300a) of the mold system (302, 303), and The injected fluid (18) is directed to one or more second downstream channels (168, 168a, 168b) and associated second gates (32, 32a, 32b), which deliver the injected fluid to the second cavity (300b) of the mold system (302, 303). The mold system (302, 302) is clamped together using a clamping device (700) under a selected clamping force. The injection fluid (18) is started and stopped from flowing from the distribution channel (160) to the first gate (34, 34a, 34b) by a first upstream valve (118), and the injection fluid is started and stopped from flowing from the distribution channel (160) to the one or more second gates (32, 32a, 32b) by a second upstream valve (108). The first upstream valve (118) is instructed to open or activate the injection fluid (18) at a first selected time to flow to the one or more first gates (34, 34a, 34b), and, The second upstream valve (108) is instructed to open or initiate the flow of the injection fluid (18) to the one or more second gates (32, 32a, 32b) at a second selected time, wherein the second selected time is delayed, subsequent or continuous in time relative to the first selected time during the injection cycle.

[0023] In another aspect of the invention, an injection molding apparatus (10a) is provided, comprising an injection molding machine (500) that injects a selected fluid (18) into a distribution manifold (800), the distribution manifold (800) guiding the injected fluid (18) to: One or more first downstream channels (166, 166a, 166b) and associated first gates (34, 34a, 34b) deliver the injection fluid (18) to a first cavity (300a) of the mold system (302, 303), and One or more second downstream channels (168, 168a, 168b) and associated second gates (32, 32a, 32b) deliver the injected fluid to the second cavity (300b) of the mold system (302, 303). The mold system (302, 302) is clamped together by the clamping device (700) under a selected clamping force. The device (10a) is adapted to cause the injection fluid (18) to flow to the one or more first gates (34, 34a, 34b) at a first selected time, and further to cause the injection fluid (18) to flow to the one or more second gates (32, 32a, 32b) at a second selected time, wherein the second selected time is delayed, subsequent or continuous in time relative to the first selected time during the injection cycle.

[0024] In such a device, the second selected time is selected such that a first peak injection fluid force or pressure occurring in the first chamber (300a) during an injection cycle occurs at a first peak time, which cancels out a second peak time at which a second peak injection fluid force or pressure occurs in the second chamber (300b) during the injection cycle.

[0025] In such a device, the second selected time is selected such that the maximum cumulative fluid force or pressure occurring in the first and second chambers (300a, 300b) during the injection cycle is less than the accumulation of the first and second peak injection fluid force or pressure.

[0026] In such a device, the second selected time is selected such that the first holding phase injection fluid force or pressure occurring in the first chamber (300a) during the injection cycle occurs during the first holding phase time, which cancels out the second holding phase injection fluid force or pressure occurring in the second chamber (300b) during the injection cycle.

[0027] In such a device, the injection fluid (18) is first injected into the first and second cavities (300a, 300b) at a filling stage pressure or force and subsequently at a holding stage pressure or force, the filling stage pressure or force being substantially less than the holding stage pressure or force.

[0028] In another aspect of the invention, a method for performing an injection cycle is provided, comprising operating any of the devices described herein to perform the injection cycle.

[0029] In another aspect of the invention, a method is provided for performing an injection cycle in an injection molding machine (500) including a distribution manifold (800), the method comprising: The injection fluid (18) is directed to: via the common distribution channel (160): One or more first downstream channels (166, 166a, 166b) and associated first gates (34, 34a, 34b) deliver the injection fluid (18) to a first cavity (300a) of the mold system (302, 303), and The injected fluid (18) is directed to one or more second downstream channels (168, 168a, 168b) and associated second gates (32, 32a, 32b), which deliver the injected fluid to the second cavity (300b) of the mold system (302, 303). The mold system (302, 302) is clamped together using a clamping device (700) under a selected clamping force. At a first selected time, the flow of the injection fluid (18) from the distribution channel (160) to the first gate (34, 34a, 34b) is initiated and stopped. And to initiate and prohibit the flow of the injection fluid from the distribution channel (160) to the one or more second gates (32, 32a, 32b) at a second selected time, which is delayed, subsequent or continuous in time relative to the first selected time during the injection cycle.

[0030] This method may include selecting a second selected time such that a first peak injection fluid force or pressure occurring in the first chamber (300a) during an injection cycle occurs at a first peak time, the first peak time offsetting a second peak time occurring in the second chamber (300b) during the injection cycle.

[0031] This method may include selecting a second selected time such that the maximum cumulative fluid force or pressure occurring in the first and second chambers (300a, 300b) during the injection cycle is less than the cumulative sum of the first and second peak injection fluid forces or pressures.

[0032] This method may include selecting a second selected time such that a first holding phase injection fluid force or pressure occurring in the first cavity (300a) during an injection cycle occurs during a first holding phase time, the first holding phase time being offset by a second holding phase time during the second cavity (300b) during the injection cycle when a second holding phase injection fluid force or pressure occurs.

[0033] This method may include injecting the injection fluid (18) into the first and second cavities (300a, 300b) first at a filling stage pressure or force and then at a holding stage pressure or force, the filling stage pressure or force being substantially less than the holding stage pressure or force. Attached Figure Description

[0034] Figure 1A It is a graph showing the relationship between clamping force required and occurring during an injection cycle and time. In a system including first and second mold cavities, the first and second mold cavities are held in a common or single clamping device, and each cavity is respectively gated by first and second gating systems. Each gating system includes two or more gates that open sequentially to fill each cavity, and each gating system simultaneously feeds or opens during the filling phase.

[0035] Figure 1B It is a graph showing the relationship between the clamping force required and occurring during the injection cycle and time, which includes the system and Figure 1A In a pair of identical mold cavities, which are held within the same common or individual clamping device, during the filling phase of each cavity, each gate system feeds or opens the pair of mold cavities in a time sequence or sequential manner, such that the clamping force required to keep the cavities closed is significantly reduced relative to the clamping force required to perform the concurrent processes.

[0036] Figure 2A This is a schematic diagram of the injection fluid density flow and cavity pressure records taken before, during, or near the start of an injection cycle at a selected time. Figure 1A , 1B The first and second cavity systems are configured to simultaneously open or supply material during the filling stage to generate... Figure 1A The image.

[0037] Figure 2B This is a schematic diagram of the injection fluid density flow and cavity pressure records taken around or near the start of an injection cycle at another selected time. Figure 1A , 1B The first and second cavity systems are used to sequentially open or feed material during the filling stage to generate... Figure 1B The image.

[0038] Figure 3A This is a schematic diagram of the injection fluid density flow and cavity pressure records taken at a selected second subsequent time point during the injection cycle. Figure 1A , 1B The first and second cavity systems are configured to simultaneously open or supply material during the filling stage to generate... Figure 1A The image.

[0039] Figure 3B This is a schematic diagram of the injection fluid density flow and cavity pressure recordings at another selected second subsequent time point during the execution of the injection cycle, using... Figure 1A , 1B The first and second cavity systems are used to sequentially open or feed material during the filling stage to generate... Figure 1B The image.

[0040] Figure 4A This is a schematic diagram of the injection fluid density flow and cavity pressure records taken at a selected third subsequent time point during the injection cycle. Figure 1A , 1B The first and second cavity systems are configured to simultaneously open or supply material during the filling stage to generate... Figure 1A The image.

[0041] Figure 4B This is a schematic diagram of the injection fluid density flow and chamber pressure records taken at another selected third subsequent time point during the injection cycle, using... Figure 1A , 1B The first and second cavity systems are used to sequentially open or feed material during the filling stage to generate... Figure 1B The image.

[0042] Figure 5A This is a schematic diagram of the injection fluid density flow and chamber pressure records taken at a selected fourth subsequent time point during the injection cycle. Figure 1A , 1B The first and second cavity systems are configured to simultaneously open or supply material during the filling stage to generate... Figure 1A The image.

[0043] Figure 5B This is a schematic diagram of the injection fluid density flow and chamber pressure recordings at another selected fourth subsequent time point during the injection cycle, using... Figure 1A , 1B The first and second cavity systems are used to sequentially open or feed material during the filling stage to generate... Figure 1B The image.

[0044] Figure 6 This is a side sectional schematic diagram of an injection molding apparatus according to the present invention, which includes a pair of upstream valves 108, 118, which are controlled to sequentially open or supply injection fluid 18 to individually controlled gates or gate systems 34, 32, which deliver injection fluid to a first mold cavity 300a and a second mold cavity 300b. The upstream valves 108, 118 receive pressurized input of injection fluid 18 from the barrel of the injection molding machine 500.

[0045] Figure 7 It is a partial sectional view of the upstream portion or surface 765 of the downstream fluid delivery channel 166 of the gating system 10a, wherein the portion or surface 755 of the valve pin 1041a and the upstream portion or surface 765 of the channel 16 are complementaryly configured to interact with each other according to the axial position of the portion 755 of the valve pin to limit and control the flow rate of the injected fluid 18 through the downstream channel and the gating 34.

[0046] Figure 8A This is a partial sectional view of the downstream end of the downstream fluid delivery channel 166, which has a gate surface region 1254 and a valve pin tip surface 1155, which are complementaryly configured to interact with each other according to the axial position of the tip surface 1155 to limit and control the rate of injected fluid 18 through the downstream channel 166 and the gate 34. The tip surface 1155 engages and contacts the gate surface region 1254 to close the gate 34, thereby stopping the fluid flow.

[0047] Figure 8B It is similar to Figure 8A The view shows the tip surface 1155 arranged in an axial position relative to the gate surface region 1254, such that the fluid flow 1154 through the travel path RP, RP2 can be restricted by the downstream or upstream movement of the control pin, wherein the rate of fluid flow 1154 is restricted relative to the flow rate when the valve pin 1041a is arranged in an upstream position (e.g., at the end of the stroke, EOS position). Detailed Implementation

[0048] Figure 1A , 1B Figures 2A, 2B, 3A, 3B, 4A, 4B, 5A, and 5B illustrate the clamping forces and injection fluid densities that can occur within the mold cavity during the injection cycle when using different injection protocols in the operation of an injection molding system, which includes a mold system having two or more separate cavities, each clamped by a single clamping device.

[0049] In the context of this disclosure, an injection cycle refers to injecting a selected fluid into at least first and second selected mold cavities over a period of time, such that the selected injection fluid fills or substantially fills at least the first and second selected mold cavities. For clarity, an injection cycle includes injecting fluid into and filling or substantially filling the first selected cavity before completing the filling or substantial filling of the second selected cavity. During the duration of the injection cycle, filling or substantially filling the mold cavity includes injecting the injection fluid such that the injection fluid follows any variable or varying fluid pressure profile applied within the mold cavity or any variable or varying flow rate profile entering the mold cavity. The profile may include any or any combination of any of the following, such as high pressure, peak pressure, high flow rate, filling pressure, filling speed, low pressure, low flow rate, low filling pressure, low filling speed, packaging pressure, packaging speed, etc.

[0050] On the right Figure 1B , 2B The diagrams shown in 3B, 4B, and 5B are clamping force diagrams. Figure 1B And injection fluid density map, Figure 2B , 3B 4B and 5B are generated in successive stages and times during the injection cycle, wherein the pair of mold cavities are clamped or held within a single clamping device, and fluid injection is provided or initiated sequentially during the filling phase of the injection cycle. The injection fluid source flowing to each mold cavity is distributed from a common or individual heating manifold. On the left side Figure 1A , 2A The diagrams shown in 3A, 4A, and 5A are clamping force diagrams. Figure 1A And injection fluid density map, Figure 2A , 3A 4A and 5A are produced at different consecutive or subsequent times during the injection cycle, wherein the pair of mold cavities are supplied or opened by a common or individual heating manifold system during the filling phase simultaneously rather than sequentially.

[0051] Used to generate Figure 1A , 2A Injection schemes using plots and maps for 3A, 4A, and 5A are typically used in traditional hot runner injection systems or schemes that do not employ sequential control of upstream valves. For example... Figure 1B , 2BAs shown in 3B, 4B, and 5B, using the cavity isolator system, method, and scheme according to the invention, a stable and reproducible predetermined curve of cavity or fluid delivery channel pressure can be achieved, or the fluid delivery channel pressure can be selectively varied within a single injection cycle. The first mold cavity can be substantially fully filled and enter the holding pressure phase (which typically requires a uniform pressure distribution), while fluid can be injected into the second mold cavity during the same injection cycle, such that the second mold cavity is still being filled after the first mold cavity has been substantially filled. This time-sequential mold cavity filling process ensures that the peak clamping force required to clamp or hold each mold at the peak of the desired filling pressure is offset, thereby ensuring that when... Figure 2A , 3A In the systems and methods shown in 3A and 4A, when simultaneous injection is used into two cavities 300a and 300b during the filling stage, as shown on the left side... Figure 1A The pressure spikes shown will decrease. In, as... Figure 2A , 3A In the conventional manifold system and injection scheme shown in 3A and 4A, the downstream programmed injection scheme sequentially injects one of the two cavities 300a by controlling a set of downstream gates 36 separately. This will interfere with the expected injection fluid pressure distribution in the other cavity 300b through another set of gates 38, causing aesthetic defects and flow front stagnation.

[0052] like Figure 1A As shown, a clamping force peak of 2600 tons is required to clamp and resist the force. Figure 2A , 3A The cumulative fluid force or pressure occurring within the two mold cavities 300a and 300b of the 4A, 5A systems and the simultaneous injection method. As shown in the figure, such a spike occurs at approximately 4.6 seconds. Figure 5A As shown, during the injection cycle, both chambers 300a and 300b are simultaneously in the pressure holding phase at approximately 4.6 seconds. Figure 2B , 3B In the sequential filling cavity system and method of 4B, 5B, the simultaneous occurrence of peak fluid forces or pressures in the two cavities 300a and 300b is avoided. The peak clamping force required during the injection cycle is approximately 2000 tons, occurring at about 5.2 seconds, when the two mold cavities 300a and 300b are in distinctly different filling stages. Therefore, in Figure 2B , 3B In a sequential filling system of 4B, 5B, the times when peak fluid forces or pressures occur in the two cavities are canceled out, and relative to... Figure 2A , 3A The cumulative peak force or pressure appearing in the 4A and 5A systems is significantly reduced in both chambers.

[0053] Figure 6 An injection molding apparatus 10a according to the invention is shown, the apparatus 10a including a pair of upstream valves 108, 118 interconnected with or controlled by a programmable controller 20, the programmable controller 20 controllably opening the pair of upstream valves 108, 118 controlling the relative time and rate at which fluid is delivered to downstream channels 166, 166a, 166b, 168, 168a, 168b and their associated gates 32, 32a, 32b, 34, 34a, 34b. Controlled upstream valves 108 and 118, controlled by controller 20, initiate the injection cycle in a predetermined time sequence. One of valves 118 opens first to deliver injection fluid 18 to the first system of gates 34, 34a, and 34b to the first mold cavity 300a at a first predetermined time, and the other of upstream valves 108 opens to deliver injection fluid 18 to the system of gates 32, 32a, and 32b to the second mold cavity 300b at a second predetermined time. As shown, the two mold cavities are mounted or clamped in clamping device 700. Clamping device 700 holds mold plates 302 and 303 together under high force or high pressure, resisting the opposing high pressure of the injection fluid 18 injected into cavities 300a and 300b, thereby keeping both cavities 300a and 300b simultaneously closed during the injection cycle.

[0054] like Figure 2B , 3B As shown in the schematic diagrams in 4B, 5B, and 6, the injection fluid 18 is supplied to the heating manifold or hot runner 800 through the supply channel 503 of the inlet 502. The heating manifold or hot runner 800 typically supplies or delivers the fluid 18 to the first chamber 300a and the second chamber 300b. The manifold 800 includes an upstream flow channel 160, which is interconnected with downstream distribution channels 162 and 164 and together supplies or delivers the injection fluid 18 to the downstream distribution channels 162 and 164. The downstream distribution channels 162 and 164 supply or deliver the fluid 18 to the first set of downstream supply channels 166, 166a, and 166b and the second set of downstream supply channels 168, 168a, and 168b, respectively.

[0055] Upstream channel 160 first controllably opens upstream valves 108 and 118 to deliver fluid 18 to downstream distribution channels 162 and 164. One of valves 108 and 118 opens first to allow the injected fluid 18 to flow to a first set of downstream fluid channels and associated gates, and the other of valves 108 and 118 opens second to allow the fluid 18 to flow to a second set of downstream channels and associated gates. Valves 108 and 118 may be further controlled by servo valves or equivalent devices 108s and 118s, or valves 108 and 118 may include servo valves or equivalent devices 108s and 118s, which may be controlled by controller 20 to open one or both of the upstream valves 108s and 118s to a selected degree of openness between 0% and 100%, such that the flow rate of the injected fluid 18 can be controlled between 0% and 100% of the maximum fluid flow rate. In such an embodiment, the controller 20 can be programmed to open upstream valves 108, 108s, 118, 118s at different or staggered times, and can also select the degree of opening during the injection cycle. The controller may include an algorithm that receives fluid pressure data from pressure sensors (such as sensors 60a, 80a) measuring fluid pressure at locations within upstream distribution channels 162, 164, located upstream of and away from gates 32, 34. This algorithm is included within the controller 20, which may include a memory storing predetermined curves of preferred fluid pressures at locations where sensors 60a, 80a are positioned and record pressure. The controller may also include instructions that direct servo or other electronically controlled valves 108s, 118s to controllably open to a certain degree during the injection cycle, such opening causing the fluid pressure to conform to the stored pressure curve at the locations of sensors 60a, 80a.

[0056] Similarly, controller 20 may include an algorithm that receives fluid pressure data from a pressure sensor (e.g., sensor 80c) measuring the fluid pressure at a position 166ua within downstream fluid channels 166, 168, positioned upstream of and away from gates 32, 34. This algorithm is included within controller 20, which may include a memory storing a predetermined curve of preferred fluid pressures at the position where sensor 80c is positioned and records pressure. The controller may further include instructions instructing actuators 50a, 50b interconnected with valve pins 1041, 1041a to move pin surfaces 755 to an axial position relative to complementary channel surfaces 765, the valve pins 1041, 1041a having, for example... Figure 7The configuration shown generates fluid pressure at upstream channel position 166a, and the fluid pressure generated at upstream channel position 166a matches the predetermined pressure curve stored at position 166a.

[0057] Similarly, controller 20 may include an algorithm that receives fluid pressure data from a pressure sensor (such as sensor 60c), which measures the fluid pressure at a location within cavities 300a, 300b, such as at or near gates 32, 34. This algorithm is included within controller 20, which may include a memory storing a predetermined curve of the preferred fluid pressure at that location, where sensor 60c is positioned and records the pressure during injection. Controller 20 may further include instructions that direct actuators 50a, 50b to move, as shown in the image. Figure 7 or Figure 8A , 8B The valve pins 1041, 1041a of the configuration shown are axially movable to position surface 755 relative to the complementary channel surface 765, or to position valve tip surface 1155 relative to gate surface 1254. This generates fluid pressure at the location of cavity sensor 60c, and the fluid pressure generated at the location of cavity sensor 60c matches a predetermined pressure curve stored at the location of sensor 60c.

[0058] In addition to the timing sequence of fluid delivery controlled by upstream valves 108s and 118s, the timing sequence of injection fluid 18 delivered through downstream supply channels 166, 166a, 166b and 168, 168a, 168b can be further individually controlled by controlling the operation of actuators 50a, 50b associated with each supply channel 166, 166a, 166b and 168, 168a, 168b. Actuators 50a, 50b are interconnected with valve pins 1041, 1041a, which can be configured to interact with the gate regions of gates 32, 34 or with complementary upstream surfaces 765, as shown in reference. Figure 7 , 8A As described in 8B.

[0059] like Figure 7As shown, the axial position of valve pins 1041a, 1041 can be controlled to position a portion of valve pin 1041a or surface 755 relative to a complementary portion or surface 765 of the downstream fluid delivery channel 166 located upstream of the gate and away from the gate, such that the fluid flowing through or across surface 765 is controllably limited to a selected flow rate. As shown, the portion or surface 755 of valve pin 1041a and the upstream portion or surface 765 of channel 16 are complementaryly configured to interact with each other according to the axial position of the portion 755 of valve pin 1041a to limit and control the rate at which the injected fluid 18 flows across surface 765, and thus also limit and control the rate at which it flows through the downstream channel 166 and gate 34. Figure 8A This is a partial sectional view of the downstream end of the downstream fluid delivery channel 166, which has a gate surface region 1254 and a valve pin tip surface 1155, which are complementaryly configured to interact with each other according to the axial position of the tip surface 1155 to limit and control the rate of injected fluid 18 through the downstream channel 166 and the gate 34. The tip surface 1155 engages and contacts the gate surface region 1254 to close the gate 34, thereby stopping the fluid flow.

[0060] Figure 8B It is similar to Figure 8A The view shows the tip surface 1155 arranged in an axial position relative to the gate surface region 1254, such that the fluid flow 1154 through the travel path RP, RP2 can be restricted by the downstream or upstream movement of the control pin, wherein the rate of fluid flow 1154 is restricted relative to the flow rate when the valve pin 1041a is arranged in an upstream position (e.g., at the end of the stroke, EOS position).

Claims

1. An injection molding apparatus (10a) comprising an injection molding machine (500) that injects a selected fluid (18) into a distribution manifold (800) having a distribution channel (160) that directs the injected fluid (18) to: One or more first downstream channels (166, 166a, 166b) and associated first gates (34, 34a, 34b) deliver the injection fluid (18) to a first cavity (300a) of the mold system (302, 303), and One or more second downstream channels (168, 168a, 168b) and associated second gates (32, 32a, 32b) deliver the injected fluid to the second cavity (300b) of the mold system (302, 303). The mold systems (302, 303) are clamped together by the clamping device (700) under a selected clamping force. The device includes a first upstream valve (118) and a second upstream valve (108), the first upstream valve (118) initiating and preventing the injection fluid from flowing from the distribution channel (160) to the first gate (34, 34a, 34b), and the second upstream valve (108) initiating and preventing the injection fluid from flowing from the distribution channel (160) to the one or more second gates (32, 32a, 32b). in, One or more first downstream valves (150b) control the delivery of injection fluid (18) through the first downstream channels (166, 166a, 166b) and the associated first gates (34, 34a, 34b), and one or more second downstream valves (150a) control the delivery of injection fluid (18) through the second downstream channels (168, 168a, 168b) and the associated second gates (32, 32a, 32b). The device also includes a control system adapted to control the timing sequence of fluid delivery through the downstream channels (166, 166a, 166b, 168, 168a, 168b) by instructing the first upstream valve (118) to open or activate the injection fluid (18) to flow to the one or more first gates (34, 34a, 34b) at a first selected time, and by further instructing the second upstream valve (108) to open or activate the injection fluid (18) to flow to the one or more second gates (32, 32a, 32b) at a second selected time, and by controlling the operation of actuators (50a, 50b) associated with each downstream channel (166, 166a, 166b, 168, 168a, 168b), wherein, during the injection cycle, the second selected time is delayed, subsequent, or consecutive to the first selected time. The controller (20) includes instructions that control the opening degree of the upstream valves (108, 118) at selected times during the injection cycle, such that the upstream valves are controllably opened to deliver fluid (18) at different selected rates and fill the mold cavities (300a, 300b) during the injection cycle. The second selected time is selected such that the selected force of the clamping device is reduced relative to the sum of the peak force or pressure exerted by the injected fluid (18) in the first and second cavities (300a, 300b), in which the injected fluid (18) is simultaneously delivered to the first gate (34, 34a, 34b) and the second gate (32, 32a, 32b) in the first and second cavities (300a, 300b). The controller (20) receives fluid pressure data from one or more pressure sensors (60c), which measure the fluid pressure at a location within a cavity (300a, 300b), and a memory that stores predetermined fluid pressure curves at the locations where the pressure is measured by the one or more pressure sensors (60c). The memory also includes instructions that direct downstream actuators (50a, 50b) to axially move valve pins (1041, 1041a). The valve pin (1041, 1041a) has a surface (1155) adapted to interact with a complementary gate surface (1254) to control the fluid pressure at the location where pressure is measured by one or more pressure sensors (60c), and the controller (20) includes instructions that instruct the actuator to move the valve pin (1041, 1041a) to a position such that the fluid pressure at the location of the pressure sensor (60c) matches the pressure of the predetermined fluid pressure curve.

2. The device of claim 1, wherein the second selected time is selected such that a first peak injection fluid force or pressure occurring in the first chamber (300a) during an injection cycle occurs at a first peak time, the first peak time offsetting a second peak time at which a second peak injection fluid force or pressure occurs in the second chamber (300b) during the injection cycle.

3. The device of claim 2, wherein the second selected time is selected such that the maximum cumulative fluid force or pressure occurring in the first and second chambers (300a, 300b) during the injection cycle is less than the sum of the first peak injection fluid force or pressure and the second peak injection fluid force or pressure.

4. The device according to any one of the preceding claims, wherein the second selected time is selected such that the first holding phase injection fluid force or pressure occurring in the first cavity (300a) during the injection cycle occurs during the first holding phase time, the first holding phase time being offset by the second holding phase time during the second cavity (300b) where the second holding phase injection fluid force or pressure occurs during the injection cycle.

5. The device according to any one of the preceding claims, wherein the injection fluid (18) is first injected into the first and second cavities (300a, 300b) at a filling stage pressure or force and subsequently at a holding stage pressure or force, wherein the filling stage pressure or force is less than the holding stage pressure or force.

6. The device according to any one of the preceding claims, wherein the selected clamping force is selected to be at least equal to the cumulative peak force or pressure exerted by the injection fluid (18) in the first and second cavities (300a, 300b) during the injection cycle.

7. The device according to any one of the preceding claims, wherein the second selected time is selected such that the time during which the injection fluid applies peak force or pressure in the first cavity during the injection cycle cancels out the time during which the injection fluid applies peak force or pressure in the second cavity during the injection cycle.

8. The device according to any one of the preceding claims, wherein one or more of the first and second downstream valves (150a, 150b) includes an actuator (50a, 50b) interconnected with a valve pin (1041, 1041a), the valve pin (1041, 1041a) having a control surface (755, 1155) having a selected configuration adapted to engage with a selected complementary surface (765, 1254) of a downstream channel (166, 168), such that the flow rate of the injected fluid (18) can be controlled by controlling the axial position of the control surface (755, 1155) of the valve pin relative to the selected complementary surface (765, 1254) of the downstream channel (166, 168).

9. The device according to any one of the preceding claims, wherein the controller (20) includes instructions that control the opening time of the upstream valves (108, 118) such that the upstream valves (108, 118) are controllably opened to deliver fluid (18) and fill the mold cavity (300a, 300b) at different or staggered times during the injection cycle.

10. The device according to any one of the preceding claims, wherein the controller (20) includes an algorithm that receives fluid pressure data from one or more pressure sensors (60a, 80a), the one or more pressure sensors (60a, 80a) being arranged at selected locations within an upstream distribution channel (162, 164) to measure fluid pressure.

11. The device of claim 10, wherein the controller (20) includes a memory storing a predetermined fluid pressure profile for the selected location, at which the sensor (60a, 80a) measures pressure, and the controller further includes an instruction instructing the upstream valve (108, 118) to open to a certain extent during the injection cycle, the opening extent of the upstream valve (108, 118) affecting the fluid pressure at the selected location, the fluid pressure matching the predetermined pressure profile during the injection cycle.

12. The device according to any one of the preceding claims, wherein the controller (20) is interconnected with one or more pressure sensors (80c), and the controller (20) receives fluid pressure data from the one or more pressure sensors (80c), the one or more pressure sensors (80c) measuring fluid pressure in downstream fluid channels (166, 168) arranged upstream of and away from the gates (32, 34) at a location (166ua), the controller (20) including a memory storing instructions Commands are made for predetermined fluid pressure profiles for locations upstream of and away from the gate (166ua), the command instructing downstream actuators (50a, 50b) to axially position interconnected valve pins (1041, 1041a), the valve pins (1041, 1041a) having pin surfaces (755) adapted to interact with complementary channel surfaces (765) to influence fluid pressures at locations upstream of and away from the gate (166ua), the fluid pressures matching the predetermined fluid pressure profiles for locations upstream of and away from the gate (166ua).

13. A method of performing an injection cycle in an injection molding machine (500) including a distribution manifold (800), the method comprising: The injection fluid (18) is directed to: via the common distribution channel (160): One or more first downstream channels (166, 166a, 166b) and associated first gates (34, 34a, 34b) deliver the injection fluid (18) to a first cavity (300a) of the mold system (302, 303), and The injected fluid (18) is directed to one or more second downstream channels (168, 168a, 168b) and associated second gates (32, 32a, 32b), which deliver the injected fluid to the second cavity (300b) of the mold system (302, 303). The delivery of injection fluid (18) through the first downstream channels (166, 166a, 166b) and associated first gates (34, 34a, 34b) is controlled by one or more first downstream valves (150b), and the delivery of injection fluid (18) through the second downstream channels (168, 168a, 168b) and associated second gates (32, 32a, 32b) is controlled by one or more second downstream valves (150a). The mold system (302, 303) is clamped together by clamping device (700) under a selected clamping force. The injection fluid (18) is started and stopped from flowing from the distribution channel (160) to the first gate (34, 34a, 34b) by a first upstream valve (118), and the injection fluid is started and stopped from flowing from the distribution channel (160) to the one or more second gates (32, 32a, 32b) by a second upstream valve (108). The opening degree of the upstream valves (108, 118) is controlled at selected times during the injection cycle, allowing the upstream valves to controllably open to deliver fluid (18) at different selected rates and fill the mold cavities (300a, 300b) during the injection cycle. This instructs the first upstream valve (118) to open or activate the injection fluid (18) at a first selected time to flow to the one or more first gates (34, 34a, 34b). The second upstream valve (108) is instructed to open or initiate the flow of the injection fluid (18) to the one or more second gates (32, 32a, 32b) at a second selected time, wherein the second selected time is delayed, subsequent, or continuous in time relative to the first selected time during the injection cycle. The second selected time is selected such that the selected force of the clamping device is reduced relative to the sum of the peak force or pressure exerted by the injected fluid (18) in the first and second cavities (300a, 300b), in which the injected fluid (18) is simultaneously delivered to the first gate (34, 34a, 34b) and the second gate (32, 32a, 32b) in the first and second cavities (300a, 300b). The control system receives fluid pressure data from one or more pressure sensors (60c), which measure fluid pressure at locations within cavities (300a, 300b), and a memory stores predetermined fluid pressure curves for the locations where the pressure is measured by the one or more pressure sensors (60c). The downstream actuators (50a, 50b) are instructed to axially move valve pins (1041, 1041a), which have surfaces (1155) adapted to interact with complementary gate surfaces (1254), to control the fluid pressure at the location where the pressure is measured by the one or more pressure sensors (60c) by moving the valve pins (1041, 1041a) to a position such that the fluid pressure at the location of the pressure sensor (60c) matches the pressure of the predetermined fluid pressure curve.

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