CA2607386A1 - Hydraulic circuit - Google Patents
Hydraulic circuit Download PDFInfo
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- CA2607386A1 CA2607386A1 CA 2607386 CA2607386A CA2607386A1 CA 2607386 A1 CA2607386 A1 CA 2607386A1 CA 2607386 CA2607386 CA 2607386 CA 2607386 A CA2607386 A CA 2607386A CA 2607386 A1 CA2607386 A1 CA 2607386A1
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- coupled
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/76—Measuring, controlling or regulating
- B29C45/82—Hydraulic or pneumatic circuits
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- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
Disclosed are: (i) a molding system (iii) a hydraulic circuit.
Description
HYDRAULIC CIRCUIT
TECHNICAL FIELD
The present invention generally relates to, but is not limited to, injection molding machines, and more specifically the present invention relates to, but is not limited to the hydraulic systems for injection molding machines.
BACKGROUND OF THE INVENTION
Examples of known molding systems are (amongst others): (i) the HyPETTM
Molding System, (ii) the QuadlocTM Molding System, (iii) the HylectricTM Molding System, and (iv) the HyMetTM Molding System, all manufactured by Husky Injection Molding Systems Ltd.
(Location: Bolton, Ontario, Canada; www.husky.ca).
United States Patent Number 7,067,078 (Inventor: Amano; Published: 2006-06-27) discloses an injection molding machine that includes an accumulator for accumulating actuator supplied oil having accumulating hydraulic pressure set in range of designated values.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a molding system (100), comprising: a frame (103);
an extruder (101) mounted to the frame (103), the extruder (101) having an injection actuator (104);
a hopper (110) configured to deliver a moldable material to the extruder (101);
a stationary platen (112) mounted to the frame (103), the stationary platen (112) configured to: (i) support, at least in part, a mold, and (ii) permit the extruder (101) to inject a moldable material into a cavity defined by the mold so as to manufacture a molded article (124);
a clamp actuator (102) mounted to the stationary platen (112);
a movable platen (114) being movable relative to the stationary platen (112);
a platen-stroke actuator (106) configured to stroke the movable platen (114);
tie bars (116) attached to the stationary platen (112) and extending from the stationary platen (112) to the movable platen (114), the tie bars (116) configured to transmit a mold clamping force to the platens (112, 114) once the tie bars (116) are locked up relative to the movable platen (114), the tie bars (116) have interuppted teeth (204) as decribed in US 2005-0287246 Al;
a tie-bar lock actuator (118) configured to lock the tie bars (116) relative to the movable platen (114);
controls (120) configured to control: (i) the clamp actuator (102), (ii) the platen-stroke actuator (106), (iii) the injection actuator (104) and (iv) the extruder (101);
a human-machine interface (HMI) (122) configured to interface with the controls (120); and a hydraulic circuit (150) configured to control (i) the clamp actuator (102), (ii) the platen-stroke actuator (106), (iii) the injection actuator (104).
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the exemplary embodiments of the present invention (including alternatives and/or variations thereof) may be obtained with reference to the detailed description of the exemplary embodiments of the present invention along with the following drawings, in which:
FIG. 1 depicts a perspective view of a molding system;
FIGS. 2A, 2B and 2C depict schematic representations of the clamp actuator 102 of the system 100 of FIG. 1 according to the second exemplary embodiment;
FIG. 3A depicts a schematic representation of the hydraulic circuit 150 (hereafter referred to as the "circuit 150") of the system 100 of FIG. 1 according to the third exemplary embodiment;
FIG. 3B depicts schematic representations of the valve 212 and the valve 220 of the circuit 150 of the system 100 of FIG. I according to the fourth exemplary embodiment;
FIG. 3C depicts a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1 according to the fifth exemplary embodiment;
FIG. 4A is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1, in which the clamp actuator 102 is placed in a reset condition;
FIGS. 4B and 4C are schematic representations of a cross-sectional view and of a frontal view, respectively, of the tie bar 116 of the system 100 of FIG. 1;
TECHNICAL FIELD
The present invention generally relates to, but is not limited to, injection molding machines, and more specifically the present invention relates to, but is not limited to the hydraulic systems for injection molding machines.
BACKGROUND OF THE INVENTION
Examples of known molding systems are (amongst others): (i) the HyPETTM
Molding System, (ii) the QuadlocTM Molding System, (iii) the HylectricTM Molding System, and (iv) the HyMetTM Molding System, all manufactured by Husky Injection Molding Systems Ltd.
(Location: Bolton, Ontario, Canada; www.husky.ca).
United States Patent Number 7,067,078 (Inventor: Amano; Published: 2006-06-27) discloses an injection molding machine that includes an accumulator for accumulating actuator supplied oil having accumulating hydraulic pressure set in range of designated values.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a molding system (100), comprising: a frame (103);
an extruder (101) mounted to the frame (103), the extruder (101) having an injection actuator (104);
a hopper (110) configured to deliver a moldable material to the extruder (101);
a stationary platen (112) mounted to the frame (103), the stationary platen (112) configured to: (i) support, at least in part, a mold, and (ii) permit the extruder (101) to inject a moldable material into a cavity defined by the mold so as to manufacture a molded article (124);
a clamp actuator (102) mounted to the stationary platen (112);
a movable platen (114) being movable relative to the stationary platen (112);
a platen-stroke actuator (106) configured to stroke the movable platen (114);
tie bars (116) attached to the stationary platen (112) and extending from the stationary platen (112) to the movable platen (114), the tie bars (116) configured to transmit a mold clamping force to the platens (112, 114) once the tie bars (116) are locked up relative to the movable platen (114), the tie bars (116) have interuppted teeth (204) as decribed in US 2005-0287246 Al;
a tie-bar lock actuator (118) configured to lock the tie bars (116) relative to the movable platen (114);
controls (120) configured to control: (i) the clamp actuator (102), (ii) the platen-stroke actuator (106), (iii) the injection actuator (104) and (iv) the extruder (101);
a human-machine interface (HMI) (122) configured to interface with the controls (120); and a hydraulic circuit (150) configured to control (i) the clamp actuator (102), (ii) the platen-stroke actuator (106), (iii) the injection actuator (104).
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the exemplary embodiments of the present invention (including alternatives and/or variations thereof) may be obtained with reference to the detailed description of the exemplary embodiments of the present invention along with the following drawings, in which:
FIG. 1 depicts a perspective view of a molding system;
FIGS. 2A, 2B and 2C depict schematic representations of the clamp actuator 102 of the system 100 of FIG. 1 according to the second exemplary embodiment;
FIG. 3A depicts a schematic representation of the hydraulic circuit 150 (hereafter referred to as the "circuit 150") of the system 100 of FIG. 1 according to the third exemplary embodiment;
FIG. 3B depicts schematic representations of the valve 212 and the valve 220 of the circuit 150 of the system 100 of FIG. I according to the fourth exemplary embodiment;
FIG. 3C depicts a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1 according to the fifth exemplary embodiment;
FIG. 4A is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1, in which the clamp actuator 102 is placed in a reset condition;
FIGS. 4B and 4C are schematic representations of a cross-sectional view and of a frontal view, respectively, of the tie bar 116 of the system 100 of FIG. 1;
x-1047-0-CA
FIG. 5A is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1 according to the seventh exemplary embodiment, in which the circuit 150 is depicted in a mold-closed operation mode;
FIG. 5B is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1 according to eight exemplary embodiment, in which the actuator 106 is operated so as to decelerate the platen 114 from maximum speed to zero speed (that is, a rest condition);
FIGS. 6A, 6B are schematic depictions of a cross-sectional view and of a frontal view, respectively, of the tie bar 116 of the system 100 of FIG. 1 according to a ninth exemplary embodiment;
FIG. 6C is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to a tenth exemplary embodiment, in which the clamp actuator 102 is pressurized so as to apply clamp tonnage to the platens 112, 114 via the tie bars 116;
FIGS. 6D, 6E are schematic depictions of a cross-sectional view and of a frontal view, respectively, of a tie bar 116 of the system 100 of FIG. 1;
FIG. 6F depicts a schematic representation of the circuit 150 of the system of FIG. 1;
FIG. 7A is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated so as to inject moldable material from the extruder 102 into the mold cavity that is defined by the mold;
FIG. 7B is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated so as to hold pressure in the rod side 104B of the injector actuator 104 (this operation is commonly called the "injection hold"
operation);
FIG. 7C is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated in a pre-pullback operation mode;
FIG. 7D is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated in a recovery operation mode;
FIG. 7E is a schematic representation of the circuit 150 of the system 100 according to another exemplary embodiment;
FIG. 8A depicts the circuit 150 of the system 100 of FIG. 1 according to an another exemplary embodiment, in which the circuit 150 is operated so as to decompress the clamp actuator 102 by placing the valve 226 in a flow condition;
FIG. 9A is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to another exemplary embodiment, in which the platen 114 is accelerated to stroke open;
FIG. 9B is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to anotherexemplary embodiment; and FIG. 10 is a schematic representation of a controller 500 of the sytem 100 of FIG. 1 operably coupled to the pressure transducers 234, 236, 238, 240.
The drawings are not necessarily to scale and are sometimes illustrated by phantom lines, diagrammatic representations and fragmentary views. In certain instances, details that are not necessary for an understanding of the embodiments or that render other details difficult to perceive may have been omitted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) FIG. 1 depicts a perspective view of a molding system 100 (hereafter referred to as the "system 100") according to the first exemplary embodiment. Preferably, the system 100 includes an injection molding system 99. The system 100 includes a hydraulic circuit 150 (not depicted in FIG. 1 but which is depicted in FIG. 3A) that is configured to control a clamp actuator 102 (which is detailed in FIG 2A). The system 100 includes some components that are known to persons skilled in the art and these known components will not be described here; these known components are described, at least in part, in the following text books (by way of example): (i) Injection Molding Handbook by Osswald/Turng/Gramann (ISBN: 3-446-21669-2; publisher: Hanser), and (ii) Injection Molding Handbook by Rosato and Rosato (ISBN: 0-412-99381-3; publisher: Chapman & Hill). Generally, the system 100 includes components, such as a frame 103 and an extruder 101 that is mounted to the frame 103. The extruder 101 has an injection actuator 104 (depicted in FIG. 3A). A hopper 110 is used to deliver a moldable material (in the form of plastic pellets or chips of metal) to the extruder 101. A stationary platen 112 is mounted to the frame (103), and the stationary platen 112 is configured to: (i) support, at least in part, a mold (not depicted), and (ii) permit the extruder 101 to inject the moldable material into a cavity defined by the mold so as to manufacture a molded article 124. The clamp actuator 102 is mounted to the stationary platen (112). A
movable platen 114 is slidable along rails 115 that are mounted to the frame 103 so that the movable platen 114 is movable relative to the stationary platen 112. A platen-stroke actuator 106 is mounted to the platens 112, 114 and is configured to stroke the movable platen 114.
Tie bars 116 are attached to the stationary platen 112 and the tie bars 116 extend from the stationary platen 112 to the movable platen 114. The tie bars 116 are configured to transmit a mold clamping force to the platens 112, 114 once the tie bars 116 are locked up relative to the movable platen 114. The tie bars 116 have interrupted teeth as described in United States Patent Application 2005/0287246 Al. A tie-bar lock actuator 118 is configured to lock the tie 4 bars 116 relative to the movable platen 114. Controls 120 are configured to control: (i) the clamp actuator 102, (ii) the platen-stroke actuator 106, (iii) the injection actuator 104 and (iv) the extruder 101. A human-machine interface (HMI) 122 is configured to interface with the controls 120 so as to permit an operator to control and monitor operations of the system 100.
The hydraulic circuit 150 (not depicted but is depicted in FIG. 3A) is configured to control (i) the clamp actuator 102, (ii) the platen-stroke actuator 106, and (iii) the injection actuator (104) amongst other actuators as may be required.
FIGS. 2A, 2B and 2C depict schematic representations of the clamp actuator 102 of the system 100 of FIG. 1 according to the second exemplary embodiment. Referring to FIG. 2A, the clamp actuator 102 includes a cylinder 132 that includes: (i) a rod side 134 having a port 140 that is configured to exchange (receive or expel) a pressurizable fluid (preferably, hydraulic oil) with the hydraulic circuit 150 of FIG. 3A, (ii) a bore side 136 that is located opposite of the rod side 134, (iii) a clamp piston 138 that is received in the cylinder 132 and is movable between the rode side 134 and the bore side 136, (iv) a rod 139 that is attached to the clamp piston 138 and is movable in the rode side 134 (and extends from the cylinder 132), (v) a spring 130 that is abuttable against the clamp piston 138 and abuttable against ground 142 (that is, the ground 142 is a stationary object such as the frame 103 and/or the stationary platen 112). Referring to FIG. 2B, the fluid is pumped or delivered into the rod side 134 (via the port 140) so as to pressurize the rod side 134 and as a result, the clamp piston 138 is moved to the right side of the FIG. 2B with sufficient force so as to overcome the force of the spring 130, and as a result the spring 130 becomes compressed so as to store potential energy into the spring 130. Referring to FIG. 2C, the fluid is released from the rod side 134 so that the rode side 134 becomes depressurized sufficiently enough so that the spring 130 releases its potential energy as kinetic energy so as to push the clamp piston 138 towards the left side of FIG. 2C.
FIG. 3A depicts a schematic representation of the hydraulic circuit 150 (hereafter referred to as the "circuit 150") of the system 100 of FIG. 1 according to the third exemplary embodiment (which is the preferred embodiment or best mode). The circuit 150 is depicted in an idle operation mode, in which the actuators 102, 104 and 106 are not actuated. The circuit 150 includes (amongst other things) a tank 152. A tank line 214 extends from the tank 152. The tank line 214 is configured to convey fluid from components of the hydraulic circuit 150 to the tank 152. A main pressure line 210 is configured to convey pressurized fluid to the components of the hydraulic circuit 150. A pump 200 includes: (i) a pump pressure port 206 that is coupled to the main pressure line 210, and (ii) a pump tank port 208 that is coupled to the tank line 214. Preferably, the pump 200 includes a fixed-displacement pump 201. The pump 200 is, for example, a vane pump or an internal-gear pump.
A motor 202 has a shaft 206 that is operatively coupled to the pump 200 so as to rotate the pump 200 once the motor 202 is activated to do so. Preferably, the motor 202 includes a variable-speed motor or servo motor 203. A pressure relief valve 211 is coupled to the main pressure line 210 and is coupled to the tank 152. The pressure relief valve 211 is configured to release the pressurizable fluid from the main pressure line 210 to the tank 152 at a predetermined pressure level (such as 240 bar). A pressure line A-side 216 is configured to convey the pressurizable fluid to the actuators 102, 104, 106 of the system 100. A pressure line B-side 218 is configured to convey the pressurizable fluid to the actuators 102, 104, 106 of the system 100.
A main control valve 212 (hereafter referred to as the "valve 212") is included in the circuit 150. The valve 212 is described in more detail below (reference is made to FIG. 3B). A pump-unloading valve 220 (hereafter referred to as the "valve 220") has: (i) an input side 221A
coupled to the main pressure line 210, and (ii) an output side (221B) coupled to the tank line (214). The valve 220 is configured to: (i) bleed a predetermined fluid flow rate of fluid (such as 40 liters per minute) to the tank 152 when or if the motor 202 rotates operates under a low-demand condition (such as 400 revolutions per minute) and the main control valve 212 is set for no flow condition, (ii) not bleed fluid to the tank 152 if the motor 202 operates under a non-low demand condition (such as, when the motor 202 rotates greater than 400 revolutions per minutes and the main control valve 212 is set to permit flow of fluid into and out from the pressure lines 216, 218), and (iii) operate when the clamp actuator 102 operates in a clamp reset operation mode. Additional details related to the operation of the actuator 102 are described below.
A platen stroke shut-off valve 222 (hereafter referred to as the "valve 222"
is coupled to the pressure line A-side 216 and is coupled to a rod side 106A of the platen-stroke actuator 106.
A platen stroke shut-off valve 224 (hereafter referred to as the "valve 224") is coupled to the pressure line B-side 218 and is coupled to a bore side 106B of the platen-stroke actuator 106.
A clamp actuator shut-off valve 226 (hereafter referred to as the "valve 226") is coupled to the pressure line B-side 218 and is coupled to the rod side 134 of the clamp actuator 102. An injection-actuator shut-off valve 228 (hereafter referred to as the "valve 228") is coupled to the pressure line B-side 218 and is coupled to a rod side 104B of the injection actuator 104.
An injection-actuator shut-off valve 230 is coupled.to the pressure line A-side 216 and is coupled to a bore side 104A of the injection actuator 104. The valves 222, 224, 226, 228, 230 are also called lockout valves.
A proportional back-pressure control valve 232 (hereafter referred to as the "valve 232") is coupled to the bore side 104A of the injection actuator 104 and is coupled to the tank 152 via the tank line 214. The purpose of the valve 232 is described below.
A pressure transducer 234 is coupled to the pressure line A-side 216. A
pressure transducer 236 is coupled to the pressure line B-side 218. A pressure transducer 238 is coupled to the bore side 104A of the injection actuator 104. A pressure transducer 240 is coupled to the rod side 134 of the clamp actuator 102. The pressure transducers 234, 236, 238, 240 are connected or operatively interfaced to a controller 500 (depicted in FIG. 10). The controller 500 monitors the pressure transducers 234, 236, 238, 240 for sensed pressures.
A pressure relief valve 242 is coupled to the rod side 106B of the platen-stroke actuator 106 and is coupled to the tank 152 via the tank line 214. A pressure relief valve 242 is coupled to the rod side 104B of the injection actuator 104 and is coupled to the tank 152 via the tank line 214. A check valve 246 is coupled to the rod side 104B of the injection actuator 104 and is coupled to the tank 152 via the tank line 214. A carriage actuator line 248 is coupled to the pressure line 210 and is configured to deliver fluid to a carriage actuator 250. The circuit 150 may be adapted to provide fluid for other actuators as may be required.
In the idle operation mode, rotational speed of the motor 202 is set or controlled for low rotational speed, and the valves 212, 222, 224, 226, 228 and 230 are placed in the no-flow condition so that the pressure lines 216, 218 are de-pressurized and the actuators 102, 104, 106 are not actuated. The motor 202 turns the pump 200 so as to actuate the pump 200 to deliver or supply a flow of pressurized fluid to the circuit 150 via the pressure line 210.
The valve 220 is actuated so as to unload pressurized fluid from the pressure line 210 to the tank 152 (via the tank line 214). The valve 220 is used to maintain a minimum flow or supply of fluid through the pump 200 so as to maintain a minimum pressure in the fluid contained in the pressure line 210. For example, the rotational speed of the motor 202 is maintained at a minimum of 400 revolutions per minute (RPM) at any given pressure output of the pump 200 during unloading of fluid to the tank 152.
FIG. 3B depicts schematic representations of the valve 212 and the valve 220 of the circuit 150 of the system 100 of FIG. I according to the fourth exemplary embodiment.
The main control valve 212 includes: (i) a pressure-side-A output 211A (hereafter referred to as the "output 211A") that is coupled to the pressure line A-side 216, (ii) a pressure-side-B output 211B (hereafter referred to as the "output 211B") that is coupled to the pressure line B-side (218), (iii) a pressure connection 211C that is coupled to the main pressure line 210, and (iv) a tank connection 211D coupled to the tank line 214. The purpose of the valve 212 is to: (i) stop all flow of fluid to the outputs 211A, 211B, (ii) permit flow of pressurized fluid from the main pressure line 210 to the pressure line A-side 216 via the pressure connection 211C to the output 21 lA while permitting flow of the pressurizable fluid from the pressure line B-side 218 back to the tank 152 via the output 211B to the tank connection 211D, and (iii) permit flow of the pressurized fluid from the main pressure line 210 to the pressure line B-side 218 via the pressure connection 211C to the output 211B while permitting flow of the pressurizable fluid from the pressure line A-side 216 back to the tank 152 via the output 211A to the tank connection 211D. Preferably, the valve 212 is a three-position, four-way proportional valve 212.
FIG. 3C depicts a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. I according to the fifth exemplary embodiment. The circuit 150 includes a hydraulic pilot circuit 250 (hereafter referred to as the "circuit 250"). The circuit 250 is used to control actuation of the valves 220, 222, 224, 226, 228 and 230. The circuit 250 has:
(i) a main pilot switch 254 that is coupled to the pressure line 210, (ii) an accumulator 256 that is coupled to the main pilot switch 254, (iii) a distribution line 258 that is coupled to the accumulator 256, (iv) pilot switches 252A, 252B, 252C, 252D, 252E, 252F each respectively coupled to the distribution line 258, and individually coupled to their respective shut-off valves 222, 224, 2236, 228, 230 and the pump un-loading valve 220, (v) a pilot pressure transducer 260 coupled to the distribution line 258, and (vi) a pilot pressure relief valve 262 coupled to the distribution line 258.
FIG. 4A is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1, in which the clamp actuator 102 is placed in a reset condition so as to permit shuttering in of tie-bar interrupted teeth 304 (hereafter referred to as the "teeth 304") of the tie bars 116 relative to sleeve-interrupted teeth 302 (hereafter referred to as the "teeth 302") of a sleeve 300. The tie-bars 216 (or column) includes a floating end that has a section containing one or more annularly-arranged rows of teeth. Each row is punctuated by at least one aligned channel. The channels provide an ability for complementary (selectively interlocking) teeth to be drawn or pushed through the channel before relative rotation obtains an interlocking engagement. The sleeve 300 is rotatably mounted in the movable platen 114. A
sleeve rotation actuator (not depicted) is coupled to the sleeve 300 and is used to rotate the sleeve 300 so as to align the teeth 302, 304 relative to each other. Further details of the teeth may be found in U.S. patent application 11/673740, which is incorporated herein by reference.
FIGS. 4B and 4C are schematic representations of a cross-sectional view and of a frontal view, respectively, of the tie bar 116 of the system 100 of FIG. 1. Teeth 302, 304 are radially offset from each other (as depicted in FIG. 4C); that is, the teeth 302, 304 are not in-line with each other. The teeth 302, 304 are being moved so as to be positioned to become enagable (meshable) with each other once the sleeve 300 is rotated to do so.
Referring back to FIG. 4A, the clamp reset operation is preferably performed (i) before the movable platen 114 is stroked toward the stationary platen 112 so as to close the mold, and (ii) after decompression of the clamp actuator 102 (that is, decompression of the rod side 134 of the actuator 102).
The motor 202 is actuated so as to rotate the pump 200 so as to pressurize fluid in the pressure line 210 while the valve 220 is actuated to as to bleed some of the pressurized fluid from the line 210 back to the tank 152; however, some fluid from the pressure line 210 is permitted to reach the rod side 134 of the actuator 102 so that the rod side 134 may be pressurized so as to in turn move the rod of the actuator (which is connected to the tie bar 116) so as to align the teeth 302, 204. In this reset position, the teeth 302 may be rotated so as to align the teeth face to face with each other. It is preferred to maintain a minimum pressure, such as 30 pounds per square inch (psi), inside the rode side 134 of the clamp actuator 102.
FIG. 5A is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1 according to the seventh exemplary embodiment, in which the circuit 150 is depicted in a mold-closed operation mode, in which the movable platen 114 is closed by actuating the actuator 106. The actuator 106 is operated so as to accelerate the movable platen 114 toward the stationary platen 112 from zero speed (that is, rest) to maximum speed.
The rotational speed of motor 202 is set to be a high rotational speed; the valves 222 and 224 change conditions from a closed (or no-flow) condition to an open (or flow) condition. The valve 220 is shut off so as to not bleed fluid from the line 210. The valve 212 is set so as to permit high flow of pressurrized fluid into line 216 through the opened valve 222 into the rod side 106B
of the actuator 106. Pressurized fluid becomes injected into rod side 106B of the actuator 106 with sufficient force so as to cause the movable platen 114 to accelerate toward the stationary platen 112 (the rod of the actuator 106 is connected to the movable platen 114). In response, the piston of the actuator 106 is moved toward the bore side 106A, and as a result pressurized fluid is made to flow from the bore side 106A past the valves 224, 212 and back to the tank 152 via the tank line 214. The rotational speed of the pump 202 is adjusted to provide the cycle time needed for closing the mold.
FIG. 5B is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1 according to eight exemplary embodiment, in which the actuator 106 is operated so as to decelerate the platen 114 from maximum speed to zero speed (that is, a rest condition). The rotational speed of the motor 202 continues to be operated at high rotational speed. The valve 212 is proportionally restricted so as to limit the amount of pressurized fluid (that is, a low flow of fluid is imposed by the valve 212) that enters the rod side 106B via the valve 222 so that in this manner the movable platen 114 may be decelerated to a slower speed and thus avoid striking the movable mold portion (supported by the movable platen 114) against a stationary mold portion (supported by the stationary platen 112). The valve 212 acts to choke flow of fluid to the actuator 106. The resistance in the valve 212 causes deceleration of the movable platen 114.
Once the movable platen 114 is stoked so as to close the mold portions of the mold, it is no longer required to continue stroking the platen 114. The valve 212 is closed, the valves 22, 224 are closed, and the valve 220 is opened so as to bleed fluid from the line 210 so that in this manner the circuit 150 is set into the idle operation mode, and the rotational speed of the motor 202 is set for low rotational speed.
FIGS. 6A, 6B are schematic depictions of a cross-sectional view and of a frontal view, respectively, of the tie bar 116 of the system 100 of FIG. 1 according to a ninth exemplary embodiment. The teeth 302 are rotated to that the teeth 302 become aligned with the teeth 304 of the sleeve 300. The teeth 302 now face the teeth 304 of the tie bar 116.
There is a gap (sometimes also called a "clearance") between the teeth 302, 304.
FIG. 6C is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to a tenth exemplary embodiment, in which the clamp actuator 102 is pressurized so as to apply clamp tonnage to the platens 112, 114 via the tie bars 116.
The valve 226 is placed in the flow condition. The valve 212 is placed in a condition so as to connect fluid from the pressure line 210 to the pressure line 216 so as to pump or deliver fluid into the rod side 134 of the actuator 102. As a result, the spring 130 of the actuator 102 become compressed so as to store potential energy.
FIGS. 6D, 6E are schematic depictions of a cross-sectional view and of a frontal view, respectively, of a tie bar 116 of the system 100 of FIG. 1. The teeth 304, 302 are now abutting each other.
Referring back to FIG. 6C, the gap between the teeth 302, 304 is eliminated (this is also called "clearing the gap"). Fluid is pumped through the valve 212 to the rod side 134 of the clamp actuator 102 so that the teeth gap becomes cleared (that is, the teeth 302, 304 abut each other;
this is also called the clamp lockout state. Now clamp tonnage is permitted to build in the rod side 134. Rotational speed of the motor 202 is set for high rotational speed to be able to provide sufficient flow of fluid into the rod side 134 to build pressure. The pressure transducer 240 is used to detect the pressure level in the rod side 134.
FIG. 6F depicts a schematic representation of the circuit 150 of the system of FIG. 1. Once the pressure in the clamp actuator 102 is reached to the clamp desired tonnage, the clamp actuator 102 is locked; that is, the valve 226 is then switched from a flow condition to no-flow condition (not depicted) once the appropriate level of tonnage has been achieved. After the valve 226 is set into the no flow state, the motor 202 rotates at a low rotational speed, and the valve 220 begins bleeding fluid from the line 210 to the tank 152.
FIG. 7A is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated so as to inject moldable material from the extruder 102 into the mold cavity that is defined by the mold. The mold is held closed and clamp tonnage is applied to the mold so as to prevent flashing of the moldable material from the mold cavity.
The valves 228, 230 are switched from a no-flow condition to a flow condition.
The valve 220 is set in a no-flow condition (so that bleeding of fluid may not occur between the line 210 and the tank 152); the valve 212 is set so as to: (i) apply or deliver fluid to the rod side 104B of the injection actuator, 104 and (ii) shunt fluid from the bore side 104A to the tanks 152. The rotational speed of the motor 202 is set for high rotational speed.
FIG. 7B is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated so as to hold pressure in the rod side 104B of the injector actuator 104 (this operation is commonly called the "injection hold"
operation). Pressure control is maintained by having the motor 202 rotate at low rotational speed.
The valve 220 bleeds some fluid from the line 210 to the tank 152. The valve 220 is used to assist in maintaining or holding pressure control during injection hold operation. A
time may be set aside for the molded article formed in the mold cavity to cool off (this condition is not depicted). During the cooling time, lock the bore (shut off the valves) and the pressure is maintained. FIG. 7C is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated in a pre-pullback operation mode so as to depressurize a machine nozzle (not depicted) and/or a hot runner (not depicted) that is coupled to the extruder 102 to thereby prevent drooling of molten molding material from the extruder 102 into the mold cavity once the mold portions are separated as described below.
This operation is also called the injection decompression mode. The rotational speed of the motor 202 is set for low speed. The flow rate through the valve 212 is set for restricted flow of fluid.
FIG. 7D is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated in a recovery operation mode. A screw of the extruder 102 is rotated to process more molding material and to accumulate the molding material into the accumulation zone. The screw is not depicted, but the screw is connected to the rod of the injection actuator 104. The valves 228, 230 are set in a no-flow condition.
During this operation mode, back pressure develops in the bore side 104A. The valve 232 is engaged so as to permit release of pressure above a predetermined limit, from the bore side 106A to the tank 152. The valve 232 controls the back pressure or the piston pressure during the recovery operation mode. The valve 246 acts as an anti-cavitation valve that is: to take the fluid back to the tank 152. During the recovery operation mode, it may be possible to perform other functions, such as, stoking the mold open.
FIG. 7E is a schematic representation of the circuit 150 of the system 100 according to another exemplary embodiment, in which the circuit 150 is operated in compression mode which includes post-pull back, post-recovery pull back in which the piston of the injection actuator 104 is pulled from the end of recovery position. These modes may be performed either sequentially or simultaneously as may be required. Depicted, the circuit 150 is operated in sequential operation mode. However, the circuit 150 may be adapted for use with a molding system operating under a simultaneous-injection mode. Simultaneous mode is described in United States Patent Application 2005-0161847 (Inventor: Weatherall et al;
Published: 2005-07-28) and therefore will not be described here in detail.
FIG. 8A depicts the circuit 150 of the system 100 of FIG. 1 according to an another exemplary embodiment, in which the circuit 150 is operated so as to decompress the clamp actuator 102 by placing the valve 226 in a flow condition. If is desired to avoid shocks in the circuit 150, there may be more control sequences involved than just this simple decompression, and in that case it is preferred to set valve 212 in the flow condition before setting the valve 226 in the flow condition to avoid shocks in the circuit 150 (sometimes this is called "reverberations").
The rotational speed of the motor 202 is set for low speed. And the valve 220 is set to bleed some fluid from the pressure line 210 back to the tank 152.
FIG. 9A is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to another exemplary embodiment, in which the platen 114 is accelerated to stroke open (or away from the platen 112). The valves 222, 224 are set for flow condition. The valve 212 is fully opened. Fluid is pumped into the bore side 106A of the patent-stroke actuator 106.
FIG. 9B is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to anotherexemplary embodiment, in which the platen 114 is decelerated before coming to a full stop. It will be appreciated that the circuit 150 may be adapted so as to control ejection actuators (not depicted) that have ejections rods that extend into the movable platen 114 so as to eject parts from the mold cavity.
The description of the exemplary embodiments provides examples of the present invention, and these examples do not limit the scope of the present invention. It is understood that the scope of the present invention is limited by the claims. The exemplary embodiments described above may be adapted for specific conditions and/or functions, and may be further extended to a variety of other applications that are within the scope of the present invention. Having thus described the exemplary embodiments, it will be apparent that modifications and enhancements are possible without departing from the concepts as described. It is to be understood that the examplary embodiments illustrate the aspects of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims.
The claims themselves recite those features regarded as essential to the present invention.
Preferable embodiments of the present invention are subject of the dependent claims.
Therefore, what is to be protected by way of letters patent are limited only by the scope of the following claims:
FIG. 5A is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1 according to the seventh exemplary embodiment, in which the circuit 150 is depicted in a mold-closed operation mode;
FIG. 5B is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1 according to eight exemplary embodiment, in which the actuator 106 is operated so as to decelerate the platen 114 from maximum speed to zero speed (that is, a rest condition);
FIGS. 6A, 6B are schematic depictions of a cross-sectional view and of a frontal view, respectively, of the tie bar 116 of the system 100 of FIG. 1 according to a ninth exemplary embodiment;
FIG. 6C is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to a tenth exemplary embodiment, in which the clamp actuator 102 is pressurized so as to apply clamp tonnage to the platens 112, 114 via the tie bars 116;
FIGS. 6D, 6E are schematic depictions of a cross-sectional view and of a frontal view, respectively, of a tie bar 116 of the system 100 of FIG. 1;
FIG. 6F depicts a schematic representation of the circuit 150 of the system of FIG. 1;
FIG. 7A is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated so as to inject moldable material from the extruder 102 into the mold cavity that is defined by the mold;
FIG. 7B is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated so as to hold pressure in the rod side 104B of the injector actuator 104 (this operation is commonly called the "injection hold"
operation);
FIG. 7C is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated in a pre-pullback operation mode;
FIG. 7D is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated in a recovery operation mode;
FIG. 7E is a schematic representation of the circuit 150 of the system 100 according to another exemplary embodiment;
FIG. 8A depicts the circuit 150 of the system 100 of FIG. 1 according to an another exemplary embodiment, in which the circuit 150 is operated so as to decompress the clamp actuator 102 by placing the valve 226 in a flow condition;
FIG. 9A is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to another exemplary embodiment, in which the platen 114 is accelerated to stroke open;
FIG. 9B is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to anotherexemplary embodiment; and FIG. 10 is a schematic representation of a controller 500 of the sytem 100 of FIG. 1 operably coupled to the pressure transducers 234, 236, 238, 240.
The drawings are not necessarily to scale and are sometimes illustrated by phantom lines, diagrammatic representations and fragmentary views. In certain instances, details that are not necessary for an understanding of the embodiments or that render other details difficult to perceive may have been omitted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) FIG. 1 depicts a perspective view of a molding system 100 (hereafter referred to as the "system 100") according to the first exemplary embodiment. Preferably, the system 100 includes an injection molding system 99. The system 100 includes a hydraulic circuit 150 (not depicted in FIG. 1 but which is depicted in FIG. 3A) that is configured to control a clamp actuator 102 (which is detailed in FIG 2A). The system 100 includes some components that are known to persons skilled in the art and these known components will not be described here; these known components are described, at least in part, in the following text books (by way of example): (i) Injection Molding Handbook by Osswald/Turng/Gramann (ISBN: 3-446-21669-2; publisher: Hanser), and (ii) Injection Molding Handbook by Rosato and Rosato (ISBN: 0-412-99381-3; publisher: Chapman & Hill). Generally, the system 100 includes components, such as a frame 103 and an extruder 101 that is mounted to the frame 103. The extruder 101 has an injection actuator 104 (depicted in FIG. 3A). A hopper 110 is used to deliver a moldable material (in the form of plastic pellets or chips of metal) to the extruder 101. A stationary platen 112 is mounted to the frame (103), and the stationary platen 112 is configured to: (i) support, at least in part, a mold (not depicted), and (ii) permit the extruder 101 to inject the moldable material into a cavity defined by the mold so as to manufacture a molded article 124. The clamp actuator 102 is mounted to the stationary platen (112). A
movable platen 114 is slidable along rails 115 that are mounted to the frame 103 so that the movable platen 114 is movable relative to the stationary platen 112. A platen-stroke actuator 106 is mounted to the platens 112, 114 and is configured to stroke the movable platen 114.
Tie bars 116 are attached to the stationary platen 112 and the tie bars 116 extend from the stationary platen 112 to the movable platen 114. The tie bars 116 are configured to transmit a mold clamping force to the platens 112, 114 once the tie bars 116 are locked up relative to the movable platen 114. The tie bars 116 have interrupted teeth as described in United States Patent Application 2005/0287246 Al. A tie-bar lock actuator 118 is configured to lock the tie 4 bars 116 relative to the movable platen 114. Controls 120 are configured to control: (i) the clamp actuator 102, (ii) the platen-stroke actuator 106, (iii) the injection actuator 104 and (iv) the extruder 101. A human-machine interface (HMI) 122 is configured to interface with the controls 120 so as to permit an operator to control and monitor operations of the system 100.
The hydraulic circuit 150 (not depicted but is depicted in FIG. 3A) is configured to control (i) the clamp actuator 102, (ii) the platen-stroke actuator 106, and (iii) the injection actuator (104) amongst other actuators as may be required.
FIGS. 2A, 2B and 2C depict schematic representations of the clamp actuator 102 of the system 100 of FIG. 1 according to the second exemplary embodiment. Referring to FIG. 2A, the clamp actuator 102 includes a cylinder 132 that includes: (i) a rod side 134 having a port 140 that is configured to exchange (receive or expel) a pressurizable fluid (preferably, hydraulic oil) with the hydraulic circuit 150 of FIG. 3A, (ii) a bore side 136 that is located opposite of the rod side 134, (iii) a clamp piston 138 that is received in the cylinder 132 and is movable between the rode side 134 and the bore side 136, (iv) a rod 139 that is attached to the clamp piston 138 and is movable in the rode side 134 (and extends from the cylinder 132), (v) a spring 130 that is abuttable against the clamp piston 138 and abuttable against ground 142 (that is, the ground 142 is a stationary object such as the frame 103 and/or the stationary platen 112). Referring to FIG. 2B, the fluid is pumped or delivered into the rod side 134 (via the port 140) so as to pressurize the rod side 134 and as a result, the clamp piston 138 is moved to the right side of the FIG. 2B with sufficient force so as to overcome the force of the spring 130, and as a result the spring 130 becomes compressed so as to store potential energy into the spring 130. Referring to FIG. 2C, the fluid is released from the rod side 134 so that the rode side 134 becomes depressurized sufficiently enough so that the spring 130 releases its potential energy as kinetic energy so as to push the clamp piston 138 towards the left side of FIG. 2C.
FIG. 3A depicts a schematic representation of the hydraulic circuit 150 (hereafter referred to as the "circuit 150") of the system 100 of FIG. 1 according to the third exemplary embodiment (which is the preferred embodiment or best mode). The circuit 150 is depicted in an idle operation mode, in which the actuators 102, 104 and 106 are not actuated. The circuit 150 includes (amongst other things) a tank 152. A tank line 214 extends from the tank 152. The tank line 214 is configured to convey fluid from components of the hydraulic circuit 150 to the tank 152. A main pressure line 210 is configured to convey pressurized fluid to the components of the hydraulic circuit 150. A pump 200 includes: (i) a pump pressure port 206 that is coupled to the main pressure line 210, and (ii) a pump tank port 208 that is coupled to the tank line 214. Preferably, the pump 200 includes a fixed-displacement pump 201. The pump 200 is, for example, a vane pump or an internal-gear pump.
A motor 202 has a shaft 206 that is operatively coupled to the pump 200 so as to rotate the pump 200 once the motor 202 is activated to do so. Preferably, the motor 202 includes a variable-speed motor or servo motor 203. A pressure relief valve 211 is coupled to the main pressure line 210 and is coupled to the tank 152. The pressure relief valve 211 is configured to release the pressurizable fluid from the main pressure line 210 to the tank 152 at a predetermined pressure level (such as 240 bar). A pressure line A-side 216 is configured to convey the pressurizable fluid to the actuators 102, 104, 106 of the system 100. A pressure line B-side 218 is configured to convey the pressurizable fluid to the actuators 102, 104, 106 of the system 100.
A main control valve 212 (hereafter referred to as the "valve 212") is included in the circuit 150. The valve 212 is described in more detail below (reference is made to FIG. 3B). A pump-unloading valve 220 (hereafter referred to as the "valve 220") has: (i) an input side 221A
coupled to the main pressure line 210, and (ii) an output side (221B) coupled to the tank line (214). The valve 220 is configured to: (i) bleed a predetermined fluid flow rate of fluid (such as 40 liters per minute) to the tank 152 when or if the motor 202 rotates operates under a low-demand condition (such as 400 revolutions per minute) and the main control valve 212 is set for no flow condition, (ii) not bleed fluid to the tank 152 if the motor 202 operates under a non-low demand condition (such as, when the motor 202 rotates greater than 400 revolutions per minutes and the main control valve 212 is set to permit flow of fluid into and out from the pressure lines 216, 218), and (iii) operate when the clamp actuator 102 operates in a clamp reset operation mode. Additional details related to the operation of the actuator 102 are described below.
A platen stroke shut-off valve 222 (hereafter referred to as the "valve 222"
is coupled to the pressure line A-side 216 and is coupled to a rod side 106A of the platen-stroke actuator 106.
A platen stroke shut-off valve 224 (hereafter referred to as the "valve 224") is coupled to the pressure line B-side 218 and is coupled to a bore side 106B of the platen-stroke actuator 106.
A clamp actuator shut-off valve 226 (hereafter referred to as the "valve 226") is coupled to the pressure line B-side 218 and is coupled to the rod side 134 of the clamp actuator 102. An injection-actuator shut-off valve 228 (hereafter referred to as the "valve 228") is coupled to the pressure line B-side 218 and is coupled to a rod side 104B of the injection actuator 104.
An injection-actuator shut-off valve 230 is coupled.to the pressure line A-side 216 and is coupled to a bore side 104A of the injection actuator 104. The valves 222, 224, 226, 228, 230 are also called lockout valves.
A proportional back-pressure control valve 232 (hereafter referred to as the "valve 232") is coupled to the bore side 104A of the injection actuator 104 and is coupled to the tank 152 via the tank line 214. The purpose of the valve 232 is described below.
A pressure transducer 234 is coupled to the pressure line A-side 216. A
pressure transducer 236 is coupled to the pressure line B-side 218. A pressure transducer 238 is coupled to the bore side 104A of the injection actuator 104. A pressure transducer 240 is coupled to the rod side 134 of the clamp actuator 102. The pressure transducers 234, 236, 238, 240 are connected or operatively interfaced to a controller 500 (depicted in FIG. 10). The controller 500 monitors the pressure transducers 234, 236, 238, 240 for sensed pressures.
A pressure relief valve 242 is coupled to the rod side 106B of the platen-stroke actuator 106 and is coupled to the tank 152 via the tank line 214. A pressure relief valve 242 is coupled to the rod side 104B of the injection actuator 104 and is coupled to the tank 152 via the tank line 214. A check valve 246 is coupled to the rod side 104B of the injection actuator 104 and is coupled to the tank 152 via the tank line 214. A carriage actuator line 248 is coupled to the pressure line 210 and is configured to deliver fluid to a carriage actuator 250. The circuit 150 may be adapted to provide fluid for other actuators as may be required.
In the idle operation mode, rotational speed of the motor 202 is set or controlled for low rotational speed, and the valves 212, 222, 224, 226, 228 and 230 are placed in the no-flow condition so that the pressure lines 216, 218 are de-pressurized and the actuators 102, 104, 106 are not actuated. The motor 202 turns the pump 200 so as to actuate the pump 200 to deliver or supply a flow of pressurized fluid to the circuit 150 via the pressure line 210.
The valve 220 is actuated so as to unload pressurized fluid from the pressure line 210 to the tank 152 (via the tank line 214). The valve 220 is used to maintain a minimum flow or supply of fluid through the pump 200 so as to maintain a minimum pressure in the fluid contained in the pressure line 210. For example, the rotational speed of the motor 202 is maintained at a minimum of 400 revolutions per minute (RPM) at any given pressure output of the pump 200 during unloading of fluid to the tank 152.
FIG. 3B depicts schematic representations of the valve 212 and the valve 220 of the circuit 150 of the system 100 of FIG. I according to the fourth exemplary embodiment.
The main control valve 212 includes: (i) a pressure-side-A output 211A (hereafter referred to as the "output 211A") that is coupled to the pressure line A-side 216, (ii) a pressure-side-B output 211B (hereafter referred to as the "output 211B") that is coupled to the pressure line B-side (218), (iii) a pressure connection 211C that is coupled to the main pressure line 210, and (iv) a tank connection 211D coupled to the tank line 214. The purpose of the valve 212 is to: (i) stop all flow of fluid to the outputs 211A, 211B, (ii) permit flow of pressurized fluid from the main pressure line 210 to the pressure line A-side 216 via the pressure connection 211C to the output 21 lA while permitting flow of the pressurizable fluid from the pressure line B-side 218 back to the tank 152 via the output 211B to the tank connection 211D, and (iii) permit flow of the pressurized fluid from the main pressure line 210 to the pressure line B-side 218 via the pressure connection 211C to the output 211B while permitting flow of the pressurizable fluid from the pressure line A-side 216 back to the tank 152 via the output 211A to the tank connection 211D. Preferably, the valve 212 is a three-position, four-way proportional valve 212.
FIG. 3C depicts a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. I according to the fifth exemplary embodiment. The circuit 150 includes a hydraulic pilot circuit 250 (hereafter referred to as the "circuit 250"). The circuit 250 is used to control actuation of the valves 220, 222, 224, 226, 228 and 230. The circuit 250 has:
(i) a main pilot switch 254 that is coupled to the pressure line 210, (ii) an accumulator 256 that is coupled to the main pilot switch 254, (iii) a distribution line 258 that is coupled to the accumulator 256, (iv) pilot switches 252A, 252B, 252C, 252D, 252E, 252F each respectively coupled to the distribution line 258, and individually coupled to their respective shut-off valves 222, 224, 2236, 228, 230 and the pump un-loading valve 220, (v) a pilot pressure transducer 260 coupled to the distribution line 258, and (vi) a pilot pressure relief valve 262 coupled to the distribution line 258.
FIG. 4A is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1, in which the clamp actuator 102 is placed in a reset condition so as to permit shuttering in of tie-bar interrupted teeth 304 (hereafter referred to as the "teeth 304") of the tie bars 116 relative to sleeve-interrupted teeth 302 (hereafter referred to as the "teeth 302") of a sleeve 300. The tie-bars 216 (or column) includes a floating end that has a section containing one or more annularly-arranged rows of teeth. Each row is punctuated by at least one aligned channel. The channels provide an ability for complementary (selectively interlocking) teeth to be drawn or pushed through the channel before relative rotation obtains an interlocking engagement. The sleeve 300 is rotatably mounted in the movable platen 114. A
sleeve rotation actuator (not depicted) is coupled to the sleeve 300 and is used to rotate the sleeve 300 so as to align the teeth 302, 304 relative to each other. Further details of the teeth may be found in U.S. patent application 11/673740, which is incorporated herein by reference.
FIGS. 4B and 4C are schematic representations of a cross-sectional view and of a frontal view, respectively, of the tie bar 116 of the system 100 of FIG. 1. Teeth 302, 304 are radially offset from each other (as depicted in FIG. 4C); that is, the teeth 302, 304 are not in-line with each other. The teeth 302, 304 are being moved so as to be positioned to become enagable (meshable) with each other once the sleeve 300 is rotated to do so.
Referring back to FIG. 4A, the clamp reset operation is preferably performed (i) before the movable platen 114 is stroked toward the stationary platen 112 so as to close the mold, and (ii) after decompression of the clamp actuator 102 (that is, decompression of the rod side 134 of the actuator 102).
The motor 202 is actuated so as to rotate the pump 200 so as to pressurize fluid in the pressure line 210 while the valve 220 is actuated to as to bleed some of the pressurized fluid from the line 210 back to the tank 152; however, some fluid from the pressure line 210 is permitted to reach the rod side 134 of the actuator 102 so that the rod side 134 may be pressurized so as to in turn move the rod of the actuator (which is connected to the tie bar 116) so as to align the teeth 302, 204. In this reset position, the teeth 302 may be rotated so as to align the teeth face to face with each other. It is preferred to maintain a minimum pressure, such as 30 pounds per square inch (psi), inside the rode side 134 of the clamp actuator 102.
FIG. 5A is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1 according to the seventh exemplary embodiment, in which the circuit 150 is depicted in a mold-closed operation mode, in which the movable platen 114 is closed by actuating the actuator 106. The actuator 106 is operated so as to accelerate the movable platen 114 toward the stationary platen 112 from zero speed (that is, rest) to maximum speed.
The rotational speed of motor 202 is set to be a high rotational speed; the valves 222 and 224 change conditions from a closed (or no-flow) condition to an open (or flow) condition. The valve 220 is shut off so as to not bleed fluid from the line 210. The valve 212 is set so as to permit high flow of pressurrized fluid into line 216 through the opened valve 222 into the rod side 106B
of the actuator 106. Pressurized fluid becomes injected into rod side 106B of the actuator 106 with sufficient force so as to cause the movable platen 114 to accelerate toward the stationary platen 112 (the rod of the actuator 106 is connected to the movable platen 114). In response, the piston of the actuator 106 is moved toward the bore side 106A, and as a result pressurized fluid is made to flow from the bore side 106A past the valves 224, 212 and back to the tank 152 via the tank line 214. The rotational speed of the pump 202 is adjusted to provide the cycle time needed for closing the mold.
FIG. 5B is a schematic representation of the hydraulic circuit 150 of the system 100 of FIG. 1 according to eight exemplary embodiment, in which the actuator 106 is operated so as to decelerate the platen 114 from maximum speed to zero speed (that is, a rest condition). The rotational speed of the motor 202 continues to be operated at high rotational speed. The valve 212 is proportionally restricted so as to limit the amount of pressurized fluid (that is, a low flow of fluid is imposed by the valve 212) that enters the rod side 106B via the valve 222 so that in this manner the movable platen 114 may be decelerated to a slower speed and thus avoid striking the movable mold portion (supported by the movable platen 114) against a stationary mold portion (supported by the stationary platen 112). The valve 212 acts to choke flow of fluid to the actuator 106. The resistance in the valve 212 causes deceleration of the movable platen 114.
Once the movable platen 114 is stoked so as to close the mold portions of the mold, it is no longer required to continue stroking the platen 114. The valve 212 is closed, the valves 22, 224 are closed, and the valve 220 is opened so as to bleed fluid from the line 210 so that in this manner the circuit 150 is set into the idle operation mode, and the rotational speed of the motor 202 is set for low rotational speed.
FIGS. 6A, 6B are schematic depictions of a cross-sectional view and of a frontal view, respectively, of the tie bar 116 of the system 100 of FIG. 1 according to a ninth exemplary embodiment. The teeth 302 are rotated to that the teeth 302 become aligned with the teeth 304 of the sleeve 300. The teeth 302 now face the teeth 304 of the tie bar 116.
There is a gap (sometimes also called a "clearance") between the teeth 302, 304.
FIG. 6C is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to a tenth exemplary embodiment, in which the clamp actuator 102 is pressurized so as to apply clamp tonnage to the platens 112, 114 via the tie bars 116.
The valve 226 is placed in the flow condition. The valve 212 is placed in a condition so as to connect fluid from the pressure line 210 to the pressure line 216 so as to pump or deliver fluid into the rod side 134 of the actuator 102. As a result, the spring 130 of the actuator 102 become compressed so as to store potential energy.
FIGS. 6D, 6E are schematic depictions of a cross-sectional view and of a frontal view, respectively, of a tie bar 116 of the system 100 of FIG. 1. The teeth 304, 302 are now abutting each other.
Referring back to FIG. 6C, the gap between the teeth 302, 304 is eliminated (this is also called "clearing the gap"). Fluid is pumped through the valve 212 to the rod side 134 of the clamp actuator 102 so that the teeth gap becomes cleared (that is, the teeth 302, 304 abut each other;
this is also called the clamp lockout state. Now clamp tonnage is permitted to build in the rod side 134. Rotational speed of the motor 202 is set for high rotational speed to be able to provide sufficient flow of fluid into the rod side 134 to build pressure. The pressure transducer 240 is used to detect the pressure level in the rod side 134.
FIG. 6F depicts a schematic representation of the circuit 150 of the system of FIG. 1. Once the pressure in the clamp actuator 102 is reached to the clamp desired tonnage, the clamp actuator 102 is locked; that is, the valve 226 is then switched from a flow condition to no-flow condition (not depicted) once the appropriate level of tonnage has been achieved. After the valve 226 is set into the no flow state, the motor 202 rotates at a low rotational speed, and the valve 220 begins bleeding fluid from the line 210 to the tank 152.
FIG. 7A is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated so as to inject moldable material from the extruder 102 into the mold cavity that is defined by the mold. The mold is held closed and clamp tonnage is applied to the mold so as to prevent flashing of the moldable material from the mold cavity.
The valves 228, 230 are switched from a no-flow condition to a flow condition.
The valve 220 is set in a no-flow condition (so that bleeding of fluid may not occur between the line 210 and the tank 152); the valve 212 is set so as to: (i) apply or deliver fluid to the rod side 104B of the injection actuator, 104 and (ii) shunt fluid from the bore side 104A to the tanks 152. The rotational speed of the motor 202 is set for high rotational speed.
FIG. 7B is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated so as to hold pressure in the rod side 104B of the injector actuator 104 (this operation is commonly called the "injection hold"
operation). Pressure control is maintained by having the motor 202 rotate at low rotational speed.
The valve 220 bleeds some fluid from the line 210 to the tank 152. The valve 220 is used to assist in maintaining or holding pressure control during injection hold operation. A
time may be set aside for the molded article formed in the mold cavity to cool off (this condition is not depicted). During the cooling time, lock the bore (shut off the valves) and the pressure is maintained. FIG. 7C is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated in a pre-pullback operation mode so as to depressurize a machine nozzle (not depicted) and/or a hot runner (not depicted) that is coupled to the extruder 102 to thereby prevent drooling of molten molding material from the extruder 102 into the mold cavity once the mold portions are separated as described below.
This operation is also called the injection decompression mode. The rotational speed of the motor 202 is set for low speed. The flow rate through the valve 212 is set for restricted flow of fluid.
FIG. 7D is a schematic representation of the circuit 150 of the system 100 of FIG. 1, in which the injector actuator 104 is operated in a recovery operation mode. A screw of the extruder 102 is rotated to process more molding material and to accumulate the molding material into the accumulation zone. The screw is not depicted, but the screw is connected to the rod of the injection actuator 104. The valves 228, 230 are set in a no-flow condition.
During this operation mode, back pressure develops in the bore side 104A. The valve 232 is engaged so as to permit release of pressure above a predetermined limit, from the bore side 106A to the tank 152. The valve 232 controls the back pressure or the piston pressure during the recovery operation mode. The valve 246 acts as an anti-cavitation valve that is: to take the fluid back to the tank 152. During the recovery operation mode, it may be possible to perform other functions, such as, stoking the mold open.
FIG. 7E is a schematic representation of the circuit 150 of the system 100 according to another exemplary embodiment, in which the circuit 150 is operated in compression mode which includes post-pull back, post-recovery pull back in which the piston of the injection actuator 104 is pulled from the end of recovery position. These modes may be performed either sequentially or simultaneously as may be required. Depicted, the circuit 150 is operated in sequential operation mode. However, the circuit 150 may be adapted for use with a molding system operating under a simultaneous-injection mode. Simultaneous mode is described in United States Patent Application 2005-0161847 (Inventor: Weatherall et al;
Published: 2005-07-28) and therefore will not be described here in detail.
FIG. 8A depicts the circuit 150 of the system 100 of FIG. 1 according to an another exemplary embodiment, in which the circuit 150 is operated so as to decompress the clamp actuator 102 by placing the valve 226 in a flow condition. If is desired to avoid shocks in the circuit 150, there may be more control sequences involved than just this simple decompression, and in that case it is preferred to set valve 212 in the flow condition before setting the valve 226 in the flow condition to avoid shocks in the circuit 150 (sometimes this is called "reverberations").
The rotational speed of the motor 202 is set for low speed. And the valve 220 is set to bleed some fluid from the pressure line 210 back to the tank 152.
FIG. 9A is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to another exemplary embodiment, in which the platen 114 is accelerated to stroke open (or away from the platen 112). The valves 222, 224 are set for flow condition. The valve 212 is fully opened. Fluid is pumped into the bore side 106A of the patent-stroke actuator 106.
FIG. 9B is a schematic representation of the circuit 150 of the system 100 of FIG. 1 according to anotherexemplary embodiment, in which the platen 114 is decelerated before coming to a full stop. It will be appreciated that the circuit 150 may be adapted so as to control ejection actuators (not depicted) that have ejections rods that extend into the movable platen 114 so as to eject parts from the mold cavity.
The description of the exemplary embodiments provides examples of the present invention, and these examples do not limit the scope of the present invention. It is understood that the scope of the present invention is limited by the claims. The exemplary embodiments described above may be adapted for specific conditions and/or functions, and may be further extended to a variety of other applications that are within the scope of the present invention. Having thus described the exemplary embodiments, it will be apparent that modifications and enhancements are possible without departing from the concepts as described. It is to be understood that the examplary embodiments illustrate the aspects of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims.
The claims themselves recite those features regarded as essential to the present invention.
Preferable embodiments of the present invention are subject of the dependent claims.
Therefore, what is to be protected by way of letters patent are limited only by the scope of the following claims:
Claims (4)
1. A molding system (100), comprising:
a frame (103);
an extruder (101) mounted to the frame (103), the extruder (101) having an injection actuator (104);
a hopper (110) configured to deliver a moldable material to the extruder (101);
a stationary platen (112) mounted to the frame (103), the stationary platen (112) configured to: (i) support, at least in part, a mold, and (ii) permit the extruder (101) to inject a moldable material into a cavity defined by the mold so as to manufacture a molded article (124);
a clamp actuator (102) mounted to the stationary platen (112);
a movable platen (114) being movable relative to the stationary platen (112);
a platen-stroke actuator (106) configured to stroke the movable platen (114);
tie bars (116) attached to the stationary platen (112) and extending from the stationary platen (112) to the movable platen (114), the tie bars (116) configured to transmit a mold clamping force to the platens (112, 114) once the tie bars (116) are locked up relative to the movable platen (114), the tie bars (116) have interuppted teeth (204) as decribed in US 2005-0287246 A1;
a tie-bar lock actuator (118) configured to lock the tie bars (116) relative to the movable platen (114);
controls (120) configured to control: (i) the clamp actuator (102), (ii) the platen-stroke actuator (106), (iii) the injection actuator (104) and (iv) the extruder (101); a human-machine interface (HMI) (122) configured to interface with the controls (120); and a hydraulic circuit (150) configured to control (i) the clamp actuator (102), (ii) the platen-stroke actuator (106), (iii) the injection actuator (104).
a frame (103);
an extruder (101) mounted to the frame (103), the extruder (101) having an injection actuator (104);
a hopper (110) configured to deliver a moldable material to the extruder (101);
a stationary platen (112) mounted to the frame (103), the stationary platen (112) configured to: (i) support, at least in part, a mold, and (ii) permit the extruder (101) to inject a moldable material into a cavity defined by the mold so as to manufacture a molded article (124);
a clamp actuator (102) mounted to the stationary platen (112);
a movable platen (114) being movable relative to the stationary platen (112);
a platen-stroke actuator (106) configured to stroke the movable platen (114);
tie bars (116) attached to the stationary platen (112) and extending from the stationary platen (112) to the movable platen (114), the tie bars (116) configured to transmit a mold clamping force to the platens (112, 114) once the tie bars (116) are locked up relative to the movable platen (114), the tie bars (116) have interuppted teeth (204) as decribed in US 2005-0287246 A1;
a tie-bar lock actuator (118) configured to lock the tie bars (116) relative to the movable platen (114);
controls (120) configured to control: (i) the clamp actuator (102), (ii) the platen-stroke actuator (106), (iii) the injection actuator (104) and (iv) the extruder (101); a human-machine interface (HMI) (122) configured to interface with the controls (120); and a hydraulic circuit (150) configured to control (i) the clamp actuator (102), (ii) the platen-stroke actuator (106), (iii) the injection actuator (104).
2. The molding system (100) of claim 1, wherein the clamp actuator (102) includes:
a cylinder (132) having:
a rod side (134) having a port (140) configured to receive a pressurizable fluid from the hydraulic circuit (150); and a bore side (136) being located opposite of the rod side (134);
a clamp piston (138) received in the cylinder (132) and being movable between the rode side (134) and the bore side (136);
a rod (139) attached to the clamp piston (138) and movable in the rode side (134);
a spring (130) abuttable against the clamp piston (138) and against ground (142).
a cylinder (132) having:
a rod side (134) having a port (140) configured to receive a pressurizable fluid from the hydraulic circuit (150); and a bore side (136) being located opposite of the rod side (134);
a clamp piston (138) received in the cylinder (132) and being movable between the rode side (134) and the bore side (136);
a rod (139) attached to the clamp piston (138) and movable in the rode side (134);
a spring (130) abuttable against the clamp piston (138) and against ground (142).
3. The molding system (100) of claim 1, wherein the the hydraulic circuit (150) includes:
a tank (152);
a tank line (214) extending from the tank (152), the tank line (214) being configured to convey fluid from components of the hyrdaulic circuit (150) to the tank (152);
a main pressure line (210) configured to convey pressurized fluid to the components of the hyrdaulic circuit (150);
a pump (200), including:
a pump pressure port (206) coupled to the main pressure line (210); and a pump tank port (208) coupled to the tank line (214) ;
a motor (202) (variabale-speed motor 202; servo motor) (202) having a shaft (206) operatively coupled to the pump (200) so as to rotate the pump (200) once the motor (202) is activated to do so;
a pressure relief valve (211) coupled to the main pressure line (210) and coupled to the tank (152), the pressure relief valve (211) configured to release presurizable fluid from the main pressure line (210) to the tank (152) at a predetermined preessure level;
a pressure line A-side (216) configured to convey the presurizable fluid to actuators (102, 104, 106) of the system (100);
a pressure line B-side (218) configured to convey the presurizable fluid to the actuators (102, 104, 106) of the system (100);
a main control valve (212) having:
a pressure-side-A output (211A) coupled to the pressure line A-side (216);
a pressure-side-B output (21113) coupled to the pressure line B-side (218);
a presure connection (211C) coupled to the main pressure line (210); and a tank connection (211D) coupled to the tank line (214), the main control valve (212) configured to: (i) stop flow of fluid to the outputs (211A, 211B), (ii) permit flow of pressurized fluid from the main pressure line (210) to the pressure line A-side (216) via the pressure connection (211 C) to the output (211 A) while permitting flow of the pressurizable fluid from the pressure line B-side (218) back to the tank (152) via the output (211B) to the tank connection (211D), and (iii) permit flow of the pressurized fluid from the main pressure line (210) to the pressure line B-side (218) via the pressure connection (211 C) to the output (211B) while permitting flow of the pressurizable fluid from the pressure line A-side (216) back to the tank (152) via the output (211A) to the tank connection (211D), a pump-unloading valve (220) having:
an input side (221A) coupled to the main pressure line (210); and an output side (221B) coupled to the tank line (214), the pump-unloading valve (220) is configured to: (i) bleed a predetermined fluid flow rate of fluid to the tank (152) when the motor (202) rotates operates under a low-demand condition and the main control valve (212) is set for no flow condition, (ii) not bleed fluid to the tank (152) if the motor (202) operates under a non-low demand condition, and (iii) operate when the clamp actuator 102 operates in a clamp reset operation mode, a platen-stroke shut-off valve (222) coupled to the pressure line A-side (216), and coupled to a rod side (106A) of the platen-stroke actuator (106);
a platen-stroke shut-off valve (224) coupled to the pressure line B-side (218) and coupled to a bore side (106B) of the platen-stroke actuator (106);
a clamp-actuator shut-off valve (226) coupled to the pressure line B-side (218) and coupled to the rod side (134) of the clamp actuator (102);
an injection-actuator shut-off valve (228) coupled to the pressure line B-side (218) and coupled to a rod side (104B) of the injection actuator (104);
an injection-actuator shut-off valve (230) coupled to the pressure line A-side (216) and coupled to a bore side (104A) of the injection actuator (104);
a proportional back-pressure control valve (232) coupled to the bore side (104A) of the injection actuator (104) and coupled to the tank (152) via the tank line (214);
a pressure transducer (234) coupled to the pressure line A-side (216);
a pressure transducer (236) coupled to the pressure line B-side (218);
an pressure transducer (238) coupled to the bore side (104A) of the injection actuator (104);
a pressure transducer (240) coupled to the rod side (134) of the clamp actuator (102);
a pressure relief valve (242) coupled to the rod side (106B) of the platen-stroke actuator (106) and coupled to the tank (152) via the tank line (214);
a pressure relief valve (242) coupled to the rod side (104B) of the injection actuator (104) and coupled to the tank (152) via the tank line (214);
a check valve (246) coupled to the rod side (104B) of the injection actuator (104) and coupled to the tank (152) via the tank line (214);and a carriage actuator line (248) coupled to the pressure line (210) and confiured to deliver fluid to a carriage actuator (250).
a tank (152);
a tank line (214) extending from the tank (152), the tank line (214) being configured to convey fluid from components of the hyrdaulic circuit (150) to the tank (152);
a main pressure line (210) configured to convey pressurized fluid to the components of the hyrdaulic circuit (150);
a pump (200), including:
a pump pressure port (206) coupled to the main pressure line (210); and a pump tank port (208) coupled to the tank line (214) ;
a motor (202) (variabale-speed motor 202; servo motor) (202) having a shaft (206) operatively coupled to the pump (200) so as to rotate the pump (200) once the motor (202) is activated to do so;
a pressure relief valve (211) coupled to the main pressure line (210) and coupled to the tank (152), the pressure relief valve (211) configured to release presurizable fluid from the main pressure line (210) to the tank (152) at a predetermined preessure level;
a pressure line A-side (216) configured to convey the presurizable fluid to actuators (102, 104, 106) of the system (100);
a pressure line B-side (218) configured to convey the presurizable fluid to the actuators (102, 104, 106) of the system (100);
a main control valve (212) having:
a pressure-side-A output (211A) coupled to the pressure line A-side (216);
a pressure-side-B output (21113) coupled to the pressure line B-side (218);
a presure connection (211C) coupled to the main pressure line (210); and a tank connection (211D) coupled to the tank line (214), the main control valve (212) configured to: (i) stop flow of fluid to the outputs (211A, 211B), (ii) permit flow of pressurized fluid from the main pressure line (210) to the pressure line A-side (216) via the pressure connection (211 C) to the output (211 A) while permitting flow of the pressurizable fluid from the pressure line B-side (218) back to the tank (152) via the output (211B) to the tank connection (211D), and (iii) permit flow of the pressurized fluid from the main pressure line (210) to the pressure line B-side (218) via the pressure connection (211 C) to the output (211B) while permitting flow of the pressurizable fluid from the pressure line A-side (216) back to the tank (152) via the output (211A) to the tank connection (211D), a pump-unloading valve (220) having:
an input side (221A) coupled to the main pressure line (210); and an output side (221B) coupled to the tank line (214), the pump-unloading valve (220) is configured to: (i) bleed a predetermined fluid flow rate of fluid to the tank (152) when the motor (202) rotates operates under a low-demand condition and the main control valve (212) is set for no flow condition, (ii) not bleed fluid to the tank (152) if the motor (202) operates under a non-low demand condition, and (iii) operate when the clamp actuator 102 operates in a clamp reset operation mode, a platen-stroke shut-off valve (222) coupled to the pressure line A-side (216), and coupled to a rod side (106A) of the platen-stroke actuator (106);
a platen-stroke shut-off valve (224) coupled to the pressure line B-side (218) and coupled to a bore side (106B) of the platen-stroke actuator (106);
a clamp-actuator shut-off valve (226) coupled to the pressure line B-side (218) and coupled to the rod side (134) of the clamp actuator (102);
an injection-actuator shut-off valve (228) coupled to the pressure line B-side (218) and coupled to a rod side (104B) of the injection actuator (104);
an injection-actuator shut-off valve (230) coupled to the pressure line A-side (216) and coupled to a bore side (104A) of the injection actuator (104);
a proportional back-pressure control valve (232) coupled to the bore side (104A) of the injection actuator (104) and coupled to the tank (152) via the tank line (214);
a pressure transducer (234) coupled to the pressure line A-side (216);
a pressure transducer (236) coupled to the pressure line B-side (218);
an pressure transducer (238) coupled to the bore side (104A) of the injection actuator (104);
a pressure transducer (240) coupled to the rod side (134) of the clamp actuator (102);
a pressure relief valve (242) coupled to the rod side (106B) of the platen-stroke actuator (106) and coupled to the tank (152) via the tank line (214);
a pressure relief valve (242) coupled to the rod side (104B) of the injection actuator (104) and coupled to the tank (152) via the tank line (214);
a check valve (246) coupled to the rod side (104B) of the injection actuator (104) and coupled to the tank (152) via the tank line (214);and a carriage actuator line (248) coupled to the pressure line (210) and confiured to deliver fluid to a carriage actuator (250).
4. The molding system (100) of claim 1, wherein the the hydraulic circuit (150) further comprisies:
a hydraluic pilot circuit (250) having:
a main pilot switch (254) coupled to the pressure line (210);
an accumulator (256) coupled to the main pilot switch (254);
a distribution line (258) coupled to the accumulator (256);
pilot switches (252A, 252B, 252C, 252D, 252E, 252F) coupled to the distribution line (258) and respectively coupled to the shut-off valves (222, 224, 2236, 228, 230) and the pump un-loading valve (220);
a pilot pressure transducer (260) coupled to the distribution line (258);
a pilot pressure relief valve (262) coupled to the distribution line (258).
a hydraluic pilot circuit (250) having:
a main pilot switch (254) coupled to the pressure line (210);
an accumulator (256) coupled to the main pilot switch (254);
a distribution line (258) coupled to the accumulator (256);
pilot switches (252A, 252B, 252C, 252D, 252E, 252F) coupled to the distribution line (258) and respectively coupled to the shut-off valves (222, 224, 2236, 228, 230) and the pump un-loading valve (220);
a pilot pressure transducer (260) coupled to the distribution line (258);
a pilot pressure relief valve (262) coupled to the distribution line (258).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2607386 CA2607386A1 (en) | 2007-10-23 | 2007-10-23 | Hydraulic circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2607386 CA2607386A1 (en) | 2007-10-23 | 2007-10-23 | Hydraulic circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2607386A1 true CA2607386A1 (en) | 2009-04-23 |
Family
ID=40580707
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2607386 Abandoned CA2607386A1 (en) | 2007-10-23 | 2007-10-23 | Hydraulic circuit |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2607386A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014183201A1 (en) * | 2013-05-14 | 2014-11-20 | Athena Automation Ltd. | High speed clamp system for an injection molding machine |
| US10532506B2 (en) | 2014-11-19 | 2020-01-14 | Niigon Machines Ltd. | Compact clamp apparatus with integrated mold break |
| CN112957008A (en) * | 2021-01-29 | 2021-06-15 | 海南省妇女儿童医学中心 | Remote palpation equipment |
| CN114311575A (en) * | 2021-12-30 | 2022-04-12 | 阿托斯(上海)液压有限公司 | Injection molding machine backpressure control device and method based on double closed-loop PID regulation |
-
2007
- 2007-10-23 CA CA 2607386 patent/CA2607386A1/en not_active Abandoned
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014183201A1 (en) * | 2013-05-14 | 2014-11-20 | Athena Automation Ltd. | High speed clamp system for an injection molding machine |
| US9333691B2 (en) | 2013-05-14 | 2016-05-10 | Athena Automation Ltd. | High speed clamp system for an injection molding machine |
| US10532506B2 (en) | 2014-11-19 | 2020-01-14 | Niigon Machines Ltd. | Compact clamp apparatus with integrated mold break |
| CN112957008A (en) * | 2021-01-29 | 2021-06-15 | 海南省妇女儿童医学中心 | Remote palpation equipment |
| CN114311575A (en) * | 2021-12-30 | 2022-04-12 | 阿托斯(上海)液压有限公司 | Injection molding machine backpressure control device and method based on double closed-loop PID regulation |
| CN114311575B (en) * | 2021-12-30 | 2024-03-29 | 阿托斯(上海)液压有限公司 | Injection molding machine back pressure control device and method based on double closed-loop PID regulation |
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