US3731727A - Pressure intensifying apparatus for a die casting machine - Google Patents

Pressure intensifying apparatus for a die casting machine Download PDF

Info

Publication number
US3731727A
US3731727A US00213629A US3731727DA US3731727A US 3731727 A US3731727 A US 3731727A US 00213629 A US00213629 A US 00213629A US 3731727D A US3731727D A US 3731727DA US 3731727 A US3731727 A US 3731727A
Authority
US
United States
Prior art keywords
piston
cylinder
pressure
chamber
molten metal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00213629A
Other languages
English (en)
Inventor
M Mitamura
M Ozeki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shibaura Machine Co Ltd
Original Assignee
Toshiba Machine Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Machine Co Ltd filed Critical Toshiba Machine Co Ltd
Application granted granted Critical
Publication of US3731727A publication Critical patent/US3731727A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
    • B22D17/20—Accessories: Details
    • B22D17/32—Controlling equipment

Definitions

  • a die casting machine for casting a molten metal in a mold includes a first piston-cylinder assembly which is operative to cause the molten metal to flow rapidly into the mold and a second piston-cylinder assembly which operates to apply an intensified fluid pressure on a piston surface of the first piston-cylinder assembly when the mold has been filled with the molten metal.
  • the operation of both the first and second piston-cylinder assemblies may be selectively achieved by means of a control valve.
  • the control valve has a piston located in a pressurized working fluid for causing the working fluid to move freely into the first piston-cylinder assembly to pour the molten metal rapidly into the mold during an initial casting process, but the same quickly closes an inlet of the working fluid to the first piston-cylinder assembly when a static pressure difference occurs between the front and rear surfaces of the piston of the control valve upon the mold becoming filled with molten metal, and then the control valve piston causes the working fluid pressure to effectively and quickly be applied on the functional surface of a piston of the second piston-cylinder assembly to generate the intensified pressure to be applied to the molten metal for making a uniform composition.
  • the present invention relates generally to a pressure intensifying apparatus for a die' casting machine and more particularly to such an apparatus for obtaining a cast metal, such as aluminum, zinc, steel and the like, having a uniform composition.
  • a molten metal is first poured into a mold cavity of a die casting machine, generally through operation of a pushing plunger, and then an intensified pressure is applied to the molten metal located within the cavity of the mold by the pushing plunger to make the composition of the resultant cast metal fine and uniform after the mold has been entirely filled with molten metal.
  • the intensified pressure occurs at a delayed time after pouring the molten metal into the cavity of the mold, the inlet runner or passage of molten metal to the mold cavity may be stopped up by a part of solidified metal to thereby prevent further movement of the molten metal.
  • the intensified pressure cannot be effectively transferred to the molten metal located in the mold cavity, and thus it is impossible to obtain a cast metal product of high quality and having a fine and uniform composition.
  • Another problem is that unpreferable results also are obtained if an excessive intensified pressure is applied to the molten metal in the cavity of the mold. This is usually caused by an abnormal function of the pressure control system for the pressure intensifying apparatus, such that a part of the molten metal is expelled from a joint portion between a movable die and a stationary die which cooperate to provide the mold of the die casting machine.
  • casting fins may undesirably be formed around the cast metal product, which must be removed therefrom by expending much labor and time in order to obtain a cast product of the desired high quality.
  • an excessive intensified pressure may also cause the mold to be broken.
  • an object of the present invention to provide an improved pressure intensifying apparatus for a die casting machine in which an intensifying pressure can be generated at a desired time and without a time delay after filling the mold with molten metal.
  • Another object of the present invention is to provide a pressure intensifying apparatus for a die casting machine in which an appropriate intensified pressure can be applied to a molten metal located within a mold without danger of breaking the mold.
  • a further object of the invention is to provide a pressure intensifying apparatus for a die casting machine capable of successfully obtaining cast products of high quality and uniform composition having no casting fins that must be removed therefrom.
  • a mold having a cavity for molding metal products therein comprising a pair of die members being relatively separable from each other.
  • An injection sleeve having one end thereof in communication with the mold cavity is provided for injecting an amount of molten metal thereinto.
  • the other end of the injection sleeve has an opening for receiving molten metal and a pusher piston slidably positioned therein for running the molten metal poured into the sleeve into the mold cavity through the one end thereof.
  • first piston-cylinder assembly having a first piston connected to the pusher piston of the injection sleeve through a connecting rod member, the first piston being movable along the cylinder under the pressure of a pressurized working fluid which may be selectively fed to the opposite functional surfaces of the first piston from a pressurized fluid supply.
  • a second pistoncylinder assembly having a second piston slidably positioned in the cylinder thereof, the second piston having a first land portion of a large diameter and a second land portion of a smaller diameter than the first land portion, both first and second land portions being integrally formed thereon, and the functional surface of the second land portion being in communication with one functional surface of the first piston to transfer an intensified fluid pressure from the former to the latter.
  • a control valve means with a non-return valve member, or check valve member, positioned in a pressurized fluid passage, the check valve being operable for first supplying a pressurized fluid to the first piston-cylinder assembly from a pressurized fluid supply to move the first piston rapidly when the mold cavity is being filled with molten metal, and then for stopping the flow of pressurized fluid being supplied to the first piston-cylinder assembly in response to the presence of a static fluid pressure difference between the opposite functional surfaces of the check valve which occurs when the first piston has stopped following the completion of the feeding of molten metal into the mold cavity.
  • FIG. 1 is an elevational sectional view, being partly broken away, of the mold of a die casting machine
  • FIG. 2 is a schematic diagram of one embodiment of a pressure intensifying apparatus for a die casting machine formed in accordance with the present invention
  • FIG. 3 is a schematic diagram of another embodiment of a pressure intensifying apparatus formed in accordance with this invention.
  • FIG. 4 is a schematic diagram of a pressure intensifying apparatus of still another embodiment of the invention.
  • FIG. 5 is a schematic diagram of a pressure intensifying apparatus of a still further embodiment formed in accordance with the invention.
  • FIG. 1 there is shown a die casting mold generally designated by the reference numeral having a stationary die 11 and a movable die 12. Dies 11 and 12 are provided with respective recesses on their facing surfaces to form a mold cavity 13 into which molten metal may be poured. The movable-die 12 may be moved towards and 'away from the stationary die 11 by any suitable mechanism of conventional design, not being shown.
  • a runner 14 is formed between the facing surfaces of the dies to run the molten metal into the cavity 13.
  • an opening 15 is provided through the stationary die 11 and a sleeve 16 for feeding molten metal through the opening 15 is also provided, as shown.
  • a radial opening 17 is provided at one end of the sleeve 16 remote from the stationary die 11 .
  • the end of the sleeve 16 is closed by a pusher piston 19 slidably inserted therein which is connected to one end of a piston rod 20 of a pressure intensifier, the description of which follows.
  • FIG. 2 wherein a first piston-cylinder assembly generally designated by the reference numeral 21 is shown having a first piston 22 ofa relatively small diameter capable of slidable movement along an inside wall of a first cylinder 23 and being connected to the other end of the connecting rod 20, which, as hereinbefore described, has one end connected to the pusher piston 19 of FIG. 1.
  • a second piston-cylinder assembly generally designated by the reference numeral 24 having a second cylinder 25 being larger in diameter than cylinder 23 and connected thereto, and a second or stepped piston 32 having a land portion 26 ofa smaller diameter adapted for being slidably inserted in the first cylinder 23 and a land portion 27 of a larger diameter adapted for being slidably inserted in the second cylinder 25.
  • a through opening 31 axially extending through the second piston 32 into which a spool-like check valve 33 is slidably inserted.
  • the check valve 33 comprises a tubular portion 34 at one end thereof, an elongate rod or stem 35 extending in one direction from a closed end of the tubular portion 34, and a terminating piston 36 on the other end of the rod 35 being slidably enclosed in a cylinder 37 having one axial end attached to an axial end of the larger cylinder 25.
  • the tubular portion 34 of check valve 33 also has at least one transverse through opening 38 near the closed or bottom end thereof, as shown.
  • bore 39 with an internal diameter larger than the outer diameter of tubular portion 34 is provided in the second piston 32 being axially aligned with the opening 31 and having an axial length sufficient to communicate therethrough within the inside of tubular portion 34 over the entire sliding stroke of the check valve 33.
  • the leftward position of the check valve 33 is limited by a stepped portion 40 provided in the opening 31.
  • an oil pump 41 For supplying pressurized working oil,there is pro vided an oil pump 41 to feed the oil from an oil tank or reservoir 42 into an accumulator 43, which is hereinafter called a pressurized oil supply.
  • a three-position electromagnetic control valve 44 having first, second and third positions 45, 46-and 47 is provided, being controlled through the selective energization and deenergization of electromagnetic solenoid coils 48 and 49.
  • control valve 44 In the device of FIG. 2, the control valve 44 is shown occupying its third position 47 due to the energization of coil 49. In this position, pressurized oil fed from the accumulator 43 against the from functional surface of the second piston 32 in the large cylinder 25 through a throttle valve 50, a conduit 51, a passage 52 of the third position 47 of control valve 44 and a conduit 53.
  • the oil return path may now be roughly traced from the leftward or rear chamber 54 behind the first piston 22 in the first cylinder 23 through a conduit 55, and through another passage 56 of the third position 47 of control valve 44 to the oil tank 42.
  • the control valve 44 assumes its neutral or second position 46, in which the conduit 53 is connected to the accumulator 43 through a throttle valve 57 of the second stage 46 having a smaller restricted section than that of the throttle valve 50, and conduit is similarly connected through a passage 58 of the second stage 46 to the tank 42.
  • the first position 45 of the control valve 44 will be assumed in place of the third stage 47 when coil 48 is energized, and then a passage 59 will connect the accumulator 43 to conduit 55 and a passage 60 will connect conduit 53 to the oil tank 42. This is used for the return movement of the pressure intensifier, the description of which follows.
  • a second valve means 6 having two stages or positions 62 and 63 and an oil pressure responsive valve 64 are provided.
  • the control valve 61 takes the first position 62 when its electromagnetic solenoid coil 65 is deenergized, and takes its second position 63 when the same coil 65 is energized.
  • the pressure responsive valve 64 is located between conduits 55 and 66, and-one end of the latter conduit 66 opens into a chamber 67 which is defined between the functional surface of the piston 36 and an end wall of the cylinder 37, as shown.
  • the valve 64 has a pair of control inlets or conduits 68 and 69 for opening and closing the control thereof, being of a conventional type, for example, with a pressure responsive diaphragm and a bias spring acting against the deviation of the diaphragm. If a higher pressure of oil exceeding a predetermined amplitude acts upon the diaphragm through the conduit 69, the valve 64 allows its passage 70 to communicate the conduit 55 with conduit 66. On the other hand, if a pressurized oil is conducted from conduit 55 into the conduit 68, the valve 64 immediately opens the passage 70 to provide communication between conduits 55 and 66 independently of the predetermined pressure amplitude previously described.
  • the passage 71 allows the conduit 69 to communicate with a chamber 72 being defined between the front surface of the large piston 32 and an end wall of the cylinder 25, thereby causing the pressure responsive valve 64 to respond to the oil pressure in the chamber 72.
  • the second position 63 of control valve 63 is assumed, its passage 73 makes conduit 66 communicate with chamber 72 of the second piston-cylinder assembly 24 to thereby communicate the chamber 72 with chamber 67 in the cylinder 37, while passage 74 of the second position 63 causes the duct 69 to communicate with the oil tank 42.
  • These valves 75 and 76 have similar construction to valve 64 described above.
  • the inlet of the first valve 75 is connected to a chamber 80 provided between a rear surface of the larger land 27 and the other end wall of the large cylinder 25.
  • the outlet of the second valve 76 is connected with the chamber 54 of the first piston-cylinder assembly 21.
  • the first control valve 75 is controlled under a pressure of oil within chamber 72 of the large cylinder 25, and responds to a predetermined pressure value of the oil to open the passage 77 thereof.
  • the second control valve 76 causes the section of passage 78 thereof to be regulated responsive to a predetermined pressure rise of oil in the duct 79, and conducts the oil in chamber 80 into chamber 54.
  • a check valve 81 across the pair of valves 75 and 76 such that the oil cannot flow therethrough in a leftward direction, as seen in FIG. 2, but the oil can flow easily therethrough in the rightward direction.
  • the pressurized oil from accumulator 43 is thus introduced into chamber 72 through the throttle valve 50, conduit 51, throttle valve 57 having a section smaller than that of valve 50, and duct 53. Then the working oil enters freely into chamber 28 through openings 38 of the check valve 33 being located at its open position and the opening 31 so that the first piston 22 will begin its movement slowly to the left along with the pusher rod 20. It will be easily understood that this slow forward movement of the piston 22 results from the smaller cross-section of the passage 57 of the control valve 44.
  • Pusher rod 20 then drives the piston 19 slowly leftward to move the molten metal 18 towards runner l4 and then pours molten metal into the cavity 13.
  • a limit switch causes the coil 49 to be energized so as to bring the third position 47 of the control valve 44 to its functional position in place of the second position 46.
  • the narrower passage 57 is removed from the oil flow passage, and passage 52 communicates duct 51 with duct 53 to feed a relatively larger amount of working oil from the accumulator 43 into the chamber 28 through throttle valve 50, conduit 51, passage 52, duct 53, chamber 72, openings 38 of the check valve 33 and the opening 31.
  • the first piston 22 can be more quickly moved leftward along with its pusher rod 20 and piston 19.
  • the molten metal 18 will thus rush into the cavity 13 through the runner 14 to rapidly fill the cavity with molten metal.
  • pressure-responsive valve 64 In response to a predetermined amplitude of oil pressure rise in the chamber 72, pressure-responsive valve 64 allows its passage to be opened under the oil pressure being transferred from chamber 72 into the valve 64 through passage 71 of valve 61 and conduit 69.
  • the chamber 67 in front of piston 36 is brought into communication with tank 42 through conduit 66, passage 70 of pressure-responsive valve 64, conduit 55 and passage 5.6 of three-position valve 44, thereby allowing oil that has filled chamber 67 to be exhausted freely into the oil tank 42.
  • the check valve 33 immediately moves rightward to close off the right side opening of bore 39 with the bottom portion of tubular portion 34 thereof. Thereafter, oil flow intended for entry into chamber 28 through the opening 31 will be effectively shut off.
  • the oil pressure rise in chamber 72 is also immediately transferred to the first pressure-responsive valve 75 causing it to open when the pressure rise overcomes the setting pressure amplitude.
  • the valve 75 opens, the passage 77 communicates conduit 79 with the chamber 80 being defined around land 26 of the stepped piston 32.
  • the stepped piston 32 begins to move leftward under the increased oil pressure in chamber 72, and at the same time the oil in chamber 80 is pressed by the end wall of the land 27, increasing its pressure, and this oil is then conducted into conduit 79 through the passage 77 of the control valve 75.
  • the second pressure-responsive valve or the second pressure-control valve 76 functions to regulate a cross section of its passage 78 to maintain the pressure of oil in chamber 80 at a predetermined level.
  • the oil leaving valve 76 is then exhausted in oil tank 42 through chamber 54, conduit 55 and passage 56 of three-position control valve 44.
  • the stepped piston 32 can now be moved leftward responsive to a pressure difference between chambers 72 and 80 to establish an intensified oil pressure in the chamber 28.
  • This intensified oil pressure is added to the function surface of the first piston 22, then is added to the molten metal filling the mold cavity 13 through the pusher rod 20 and piston 19 so that the resultant cast product being obtained will possess a fine and uniform composition.
  • check valve 33 An examination of the prior art indicates that the most simple construction of the check valve 33 would be a spool-like one with a coiled bias spring positioned in a tubular portion 34. These check valves were not provided with portions such as the stem 35 and piston 36. The bias spring was provided with one end seated on stepped portion 40 in the opening 31 and the other end seated on the bottom tubular portion 34 of check valve 33. It was found that it was very difficult to determine the biasing force of the spring for the following reasons.
  • the pressurized oil easily enters the chamber 28 by pushing the check valve forward against the spring bias to push the first piston 22 forward with rod 20 in a rapid manner, but once the piston 22 is stopped by filling of the cavity 13 with molten metal, the opening 31 is closed slowly due to the weak spring force.
  • oil flow would continue through opening 31 towards chamber 28, so that the time at which the pressure intensifying function by the second piston 32 occurs is unpreferably delayed, whereby solidification of the molten metal 18 may occur at the runner 14 to prevent the intensified pressure being caused by the second piston-cylinder assembly 24 from being effectively transferred to the molten metal in the cavity 13. This obviously causes cast products to be produced having rough and non-uniform composition.
  • the die casting machine of this invention has no spring-biased check valve.
  • the check valve 33 can be moved to close the opening 31 under a pressure difference that may be caused by a difference of size between front and back surfaces of a bottom portion of the tubular member 34 of check valve 33.
  • the closing operation of the check valve 33 may occur at an earlier time or as soon as movement of the pusher rod 20 has been stopped due to the molten metal filling the mold cavity 13.
  • the check valve 33 closes communication between the chambers 28 and 72 before the second piston 32 starts its leftward movement for pressure-intensifying purposes.
  • no overshooting of the pressure-responsive valve 76 may occur, and it is possible to obtain the most preferable intensified pressure for applying to the molten metal in the mold cavity 13 to manufacture cast products having fine and uniform composition and without having cast fins.
  • solenoid coil 65 of the two-position control valve 61 is energized by any suitable timer relay, not shown, and the first position 62 is then replaced by the second position 63.
  • passage 73 of second position 63 causes the chamber 72 to communicate with the chamber 67 of cylinder 37 through passage 73 and conduit 66, and passage 74 releases the control oil of pressure-responsive valve 64 towards oil tank 42 through conduit 69, to bring the passage 70 thereof to a closed position.
  • a pressurized oil is introduced from chamber 72 into chamber 67 to advance the piston 36 forward along with tubular portion 34 and stem 35 of check valve 33 to reopen the opening 31 of stepped piston 32.
  • the pressurized oil from accumulator 43 is again supplied into chamber 28 to advance the first piston 22 forward along with pusher rod 20 and piston 19, and accordingly solidified molten metal 18 left in the sleeve 16 is pushed out of the left end of the sleeve 16 when the movable die 12 is moved away from the stationary die 11.
  • coil 65 is deenergized to reset the control valve 61 to a position, as shown, and then solenoid coil 48 of the three-position control valve 44 is energized.
  • the first position 45 thus comes to its working position to communicate conduit 55 with accumulator 43 through passage 59 and to communicate conduit 53 with the oil tank 42 through passage 60.
  • the pressurized oil from accumulator 43 is supplied into chamber 54 through the passage 59 and conduit 55 and the oil in chamber 72 may be exhausted therefrom into the oil tank 42.
  • the pressurized oil in conduit 55 is added to the pressureresponsive valve 64 through conduit 68 to communicate conduit 55 with conduit 66 through passage 70 therein.
  • the control valve 64 is so made that the passage 70 thereof is easily opened at a lower pressure than that being received from conduit 69. This is easily achieved by providing a larger pressure function area for oil to be entered through conduit 68 than that for oil from conduit 69.
  • the pressurized oil from accumulator 43 is also supplied into chamber 67 to fill the same with oil so long as the conduit 55 is connected to the accumulator 43.
  • the check valve 33 is thus held in a position such that the opening 31 is open to bore 39 through opening 38 so that chambers 28 and 72 are communicated with each other freely through the opening 31.
  • the first piston 22 then moves to the right under the pressure of the pressurized oil being supplied to the chamber 54, and the oil in chamber 28 is exhausted into tank 42 through opening 31 of stepped piston 32, openings 38 of the check valve 33, chamber 72 in cylinder 25, conduit 53 and passage 60 of the threeposition control valve 44.
  • the oil in chamber 54 is also fed into chamber 80 around the smaller land portion 26 of stepped piston 32 through check valve 81.
  • both pressureresponsive valves 75 and 76 close their passages 77 and 78 at this time.
  • the first piston 22 is returned towards its initial position, and the stepped piston 32 is also returned rightward towards its initial position.
  • FIG. 3 shows another embodiment of the invention that is nearly the same as that of FIG. 2, except for an arrangement including a second control valve 83 and a check valve 84, replacing control valve 61.
  • the second control valve 83 also has two stages or positions, the first being designated by the numeral 85 and the second by 86, with the former one 85 being as indicated when an electromagnetic solenoid coil 87 is deenergized, and being replaced by the latter one 86 when the coil 87 is energized.
  • Check valve 84 is located between the conduits 66 and 88 so that oil flow can take place only in a direction from conduit 88 to conduit 66.
  • the control valve 83 Upon the quick feeding of the piston 22 together with its pusher rod 20 for pouring molten metal into mold cavity 13, the control valve 83 takes its first posi' tion 85, as shown, to communicate chamber 72 of cylinder 25 with conduit 69 through passage 89. In this case, passage 89 of the first position 85 of check valve 83 communicates conduit 88 with oil tank 42, but the check valve 84 does not allow oil flow to take place therethrough. As described above, since chamber 67 is filled with oil to position the spool-like check valve 33 at its most leftward position, pressurized oil from accumulator 43 is supplied into chamber 28 through conduit 53, chamber 72 and opening 31 of the piston 32.
  • coil 87 is energized to change the valve 83 from its first position to its second position 86.
  • the pressurized oil is then supplied from conduit 53 through passage 90 and check valve 84 into chamber 67 to move the spool like check valve 33 leftward, and the same is freely flown into chamber 28 through chamber 72 and opening 31 to move the first piston 22 leftward together with its pusher rod 20, while passage 91 releases the pressure applied on the control valve 64 through conduit 69 and to the oil tank 42 to reset passage 70 for shutting off communication between conduits 55 and 66.
  • FIG. 4 shows still another embodiment of the invention, in which a spool-like check valve assembly generally designated by a reference numeral 93 has been taken outside of the stepped piston 32.
  • the check valve assembly 93 comprises a cylinder 94 having three tandem chambers 95, 96 and 97, a piston 98 slidably arranged in the chamber 95, another piston 99 slidably arranged in the chamber 97 and a connecting rod 100 connecting the pistons 98 and 99 to each other and extending therebetween.
  • a further chamber 101 communicating with the chamber 28 of the first pistoncylinder assembly 21 between the piston 22 and the piston 32 through conduits 102 and 103, and the upper portion of piston 98 is slidably enclosed in the chamber 101.
  • the chamber 95 has a valve seat 104 on which the piston 98 can be seated or removed therefrom.
  • An eleetromagnetically operable two-position coritrol valve 105 is provided, being similar to valve 61 of the embodiment shown in FIG. 2, and having a solenoid coil 106 and first and second positions 107 and 108.
  • the first position 107 of valve 105 has two passages 109 and 110, similarly the second position 108 has two passages 111 and 112, and the valve takes a position as shown so long as the coil 106 is deenergized.
  • the first position 107 is replaced by the second position 108 as the active position.
  • Chamber 95 is connected to a control inlet of pressure-responsive valve 64 in a manner similar to that of the embodiment shown in FIG. 2 through conduit 113, passage 110 of control valve 105 and conduit 69. Another control inlet for the valve 64 is connected to conduit 55 through conduit 68 also in the same manner as that of FIG. 2.
  • Chamber 96 of check valve 93 is connected to the chamber 72 in front of the second piston 32 through conduit 114 and pressure-responsive valve 115. The valve 115 is controlled under the pressure of pressurized oil in chamber 72 and communicates chamber 72 through passage 116 with conduit 114 so as to regulate the oil pressure in chamber 72 to a predetermined amplitude.
  • Chamber 96 of check valve 93 is also connected to conduit 53, which in turn is connected to the control valve 44 and related devices as described by reference to FIG. 2.
  • an electromagnetically controllable valve 117 having a passage 118 which is brought to a position where conduit 66 is communicated with conduit 53 when a solenoid coil 119 is energized.
  • a pressure control oil inlet of pressure-responsive control valve 75 is connected to the chamber 28 in the first piston-cylinder assembly 21.
  • piston 98 Since the lower end surface of piston 98 has a smaller pressure-receiving area than the upper one thereof by an amount equal to the cross-section of rod 100, the piston 98 is moved downward in response to the pressure difference thereon and is seated on the valve seat 104 to shut off the oil flow therethrough.
  • the pressurized oil in chamber 28 also operates on the pressure-responsive valve 64 through conduits 102 and 113, passage 110 of valve 105 and conduit 69 to communicate the chamber 97 below the piston 99 with conduit 55 through its passage 70 and conduit 66, so that oil in the chamber 97 is released to oil tank 42 to allow the downward movement of the piston 98.
  • the increased oil pressure in chamber 28 operates on pressure-responsive valve through conduit 120 to allow the passage 77 to communicate chamber 80 in the cylinder 25 of the second pistoncylinder cylinder assembly 24 with chamber 54 in cylinder 23 of the first piston-cylinder assembly 21, and then with oil tank 42 through conduit 55 and passage 56 of the three-position control valve 44.
  • the pressurized oil is fed from accumulator 43 into chamber 72 in front of the piston 32 through throttle valve 50, passage 52 of valve 44, conduits 53 and 114 and passage 116 of pressure regulation valve 115.
  • working oil regulated to a desired amplitude by the pressure regulation valve 115 is fed into chamber 72 so that the piston 32 can provide a desired intensified oil pressure to be added to the molten metal in cavity 13, as described by reference to FIG. 2.
  • the mold 10 After solidification of the molten metal in the mold cavity 13, the mold 10 is opened to take out the cast product, and then solenoid coil 119 of control valve 117 is energized to feed working oil from accumulator 43 into chamber 97 below the piston 99 through passage 1 18 of the valve 117.
  • the spoollike check valve 93 opens its valve seat 104 again to feed working oil into chamber 28 through conduit 53, chambers 96 and and conduit 102, so that the piston 22 is advanced forwardly along with pusher rod 20 in order to remove the solidified metal from the sleeve 16.
  • coil 106 of control valve is energized to communicate the chamber 95 of valve 93 with tank 42 through passage 112 to thereby discharge oil in the chamber 28 into oil tank 42, as well as to communicate conduit 69 with tank 42 through passage 111 to reset the pressure-responsive valve 64.
  • the piston 22 can be moved freely to the right.
  • the coil 119 is deenergized, and then coil 48 of the three-position control valve 44 is energized so that the third position 47 of the valve 44 is replaced by the first position 45 as the active position.
  • Pressurized working oil is then fed from accumulator 43 into chamber 54 through passage 59 and conduit 55. From conduit 55 a part of the working oil is conducted to conduit 68 so that the passage 70 of valve 64 is actuated to allow conduits 66 and 55 to communicate with each other.
  • piston 99 again rises to remove piston 98 from its seat 104 so that the oil in chamber 28 can be exhausted into tank 42 through conduit 102, chambers 95 and 96 of valve 93, conduit 53 and passage 60 of the three-position valve 44.
  • the piston 22 is returned rightward towards its initial position.
  • a further part of the oil can be taken from chamber 54 into chamber 80 through check valve 81 so that the stepped piston 32 is returned towards its rightward initial position.
  • FIG. shows a still further embodiment of the invention, in which the first piston-cylinder assembly 21 and the second piston-cylinder assembly 24 are made separately and are connected to each other through a conduit 121, as shown.
  • the piston-cylinder assembly 24 can be located freely at a position remote from the first assembly 21 so that there may be obtained much more freedom in the manufacture and building of the die casting machine.
  • Pressure intensifying apparatus for a die casting machine comprising:
  • a mold having relatively separable dies facing each other and defining a mold cavity therebetween for receiving molten metal for making a cast product
  • a sleeve member having one end thereof connected to said mold for feeding an amount of molten metal into said cavity
  • a first piston-cylinder assembly having a first cylinder slidably receiving a first piston, another piston slidably disposed in said sleeve for forcing molten metal therefrom and into said mold cavity, and a pusher rod having one end connected to the first piston and extending from one end of the first cylinder and its other end connected to said another piston in said sleeve;
  • a second piston-cylinder assembly having a second piston and a second cylinder slidably receiving said second piston, said second piston being formed with a first land portion and a second land portion of greater diameter than the first land portion and said second cylinder being provided with a first portion substantially equal in diameter to said first land portion being slidably disposed therein and a second portion substantially equal in diameter to said second land portion being slidably disposed therein and a chamber in said first portion of said second cylinder on one side of said first land portion being open to said first cylinder on the first piston side thereof so as to enable a fluid pressure to be transmitted from said chamber of said second cylinder onto a functional surface of said first piston;
  • means for feeding a working fluid into first cylinder on the first piston side thereof comprising a spoollike check valve member positioned in said working fluid to allow said working fluid to flow into said first cylinder to move said first piston so as to feed molten metal into the mold cavity, said check valve including axially opposed end surfaces having different pressure-receiving surface areas so that the check valve shuts off the feeding of working fluid into said first piston side of said first cylinder in response to a sudden increase in pressure of the working fluid therein which occurs when the movement of said first piston has been stopped by the filling of said mold cavity with molten metal; and,
  • said second piston of second piston-cylinder assembly is provided with an axially extending through opening for flowing a working fluid therethrough and a bore provided at an intermediate position along the longitudinal axis of the opening, said bore having a larger internal diameter than that of the opening;
  • said spool-like check valve includes a tubular portion slidably located in said through opening having an open end facing towards the functional surface of said first piston, a closed bottom opposite said open end, and at least one radial opening through which the working fluid can flow, a stern member extending from the bottom of said tubular portion longitudinally through said through opening and end wall of second cylinder of said second pistoncylinder assembly, and a piston mounted on the end of said stern being slidably received in an additional cylinder mounted on said end wall of said second piston-cylinder assembly,
  • said spool-like check valve being capable of movement along said through opening by a defined stroke so that said radial opening of the tubular portion thereof is always exposed in said bore over the entire stroke of said check valve, one of the axially opposite surfaces of said bottom of the tubular portion having a larger pressure-receiving surface area than the other surface by an amount equal to the cross-section of said stem so that a pressure difference resulting therefrom causes said check valve to close said through opening in a direction depending upon the pressure difference when a static fluid pressure is developed on the bottom, and said piston being mounted on the end of saidstem causing said bottom of said tubular portion to move away from its closed portion to open said through opening when a working fluid is supplied onto the functional surface thereof in said additional cylinder.
  • Pressure intensifying apparatus for a die casting machine further comprising:
  • a spring-biased fluid back pressure control valve connected in series with a passage for exhausting fluid from a chamber defined by a stepped portion of said second piston between said land portions and said second cylinder so that a predetermined intensified fluid pressure can be provided by said second piston-cylinder assembly.
  • Pressure intensifying apparatus for a die casting machine further comprising:
  • a pressure-responsive valve connected with said second cylinder and said additional cylinder and being responsive to a sudden increase in pressure of the working fluid in a chamber in front of said second piston so that a working fluid filling a chamber in front of said piston in said additional cylinder may be exhausted from the additional cylinder to allow movement of the piston therein to close said through opening in said second piston.
  • said first cylinder of said first piston-cylinder assembly has its one open end directly connected to an open end of said second cylinder of said second piston-cylinder assembly, and the open end of said first cylinder is provided with a portion having a diameter substantially equal to that of said first land portion of the second piston for slidably receiving the same.
  • a cylinder having first, second, third and fourth chambers arranged in tandem therein, the second chamber having an opening with a valve seat for fluidly connecting the second chamber with the third chamber therethrough, and first and second pistons connected to each other through a piston rod, a part of said first piston being slidably received in said first chamber, said first piston being also provided with opposing first and second.
  • the second surface having a smaller area that the first surface by an amount substantially equal to the cross-section area of said piston rod and a shape suitable for seating on said valve seat of the second chamber to shut off said opening against fluid flow therethrough;
  • said first and second chambers are communicated with a chamber in front of said first piston of said first piston-cylinder assembly, said third chamber is connected to a pressurized fluid supply, and said fourth chamber may be connected to the fluid supply when required for causing said first piston of said check valve to open said valve seat and is released when a pressurized fluid is supplied from the supply to said third chamber.
  • said second piston of said piston-cylinder assembly is of solid construction, said spool-like check valve member is located outside of said second piston, and a pressure control valve is positioned in an upward stream of the working fluid that flows into a chamber of the second cylinder in front of said second piston to thereby generate a desirable intensified pressure from said second piston-cylinder assembly in response to the pressure of the working fluid in said chamber.
  • first and second piston-cylinder assemblies are spaced apart and are connected through conduit means for transferring an intensified fluid pressure from the second piston-cylinder assembly to the first piston-cylinder assembly.
  • Pressure intensifying apparatus for a die casting machine comprising:
  • a mold having relatively separable dies facing each other and defining a mold cavity therebetween for receiving molten metal for makin a cast product; a sleeve member having one end t ereof connected to said mold for feeding an amount of molten metal into said cavity;
  • first piston transfer means having a part thereof slidably disposed in said sleeve for feeding said molten metal therefrom and into said cavity;
  • fluid flow control means for positioning said check valve to permit fluid flow therethrough to operate said first piston transfer means and upon filling said mold cavity being responsive for positioning said check valve to prevent further flow through said second piston transfer means, and further for subsequently operating said second piston transfer means to intensify the pressure of said fluid acting upon said first piston transfer means.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)
US00213629A 1970-12-29 1971-12-29 Pressure intensifying apparatus for a die casting machine Expired - Lifetime US3731727A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP45130288A JPS518097B1 (enrdf_load_stackoverflow) 1970-12-29 1970-12-29

Publications (1)

Publication Number Publication Date
US3731727A true US3731727A (en) 1973-05-08

Family

ID=15030719

Family Applications (1)

Application Number Title Priority Date Filing Date
US00213629A Expired - Lifetime US3731727A (en) 1970-12-29 1971-12-29 Pressure intensifying apparatus for a die casting machine

Country Status (3)

Country Link
US (1) US3731727A (enrdf_load_stackoverflow)
JP (1) JPS518097B1 (enrdf_load_stackoverflow)
DE (1) DE2165325A1 (enrdf_load_stackoverflow)

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2505648A1 (de) * 1974-02-12 1975-08-14 Toshiba Machine Co Ltd Einspritzvorrichtung fuer spritzgussmaschinen
US4147200A (en) * 1977-07-11 1979-04-03 Ford Motor Company Method and apparatus for eliminating entrapped gas in die castings
US5119866A (en) * 1988-09-30 1992-06-09 Ube Industries, Ltd. Method and apparatus for controlling a casting process by controlling the movement of a squeezing plunger
US5207267A (en) * 1990-08-09 1993-05-04 Toshiba Kikai Kabushiki Kaisha Injection control method of die cast machine
US5365999A (en) * 1992-06-05 1994-11-22 Maschinenfabrik Mueller-Weingarten Ag Method for the process control of a pressure diecasting machine and an apparatus for carrying out the method
US8459331B2 (en) 2011-08-08 2013-06-11 Crucible Intellectual Property, Llc Vacuum mold
US8701742B2 (en) 2012-09-27 2014-04-22 Apple Inc. Counter-gravity casting of hollow shapes
US8813813B2 (en) 2012-09-28 2014-08-26 Apple Inc. Continuous amorphous feedstock skull melting
US8813814B2 (en) 2012-09-28 2014-08-26 Apple Inc. Optimized multi-stage inductive melting of amorphous alloys
US8813818B2 (en) 2011-11-11 2014-08-26 Apple Inc. Melt-containment plunger tip for horizontal metal die casting
US8813817B2 (en) 2012-09-28 2014-08-26 Apple Inc. Cold chamber die casting of amorphous alloys using cold crucible induction melting techniques
US8813816B2 (en) 2012-09-27 2014-08-26 Apple Inc. Methods of melting and introducing amorphous alloy feedstock for casting or processing
US8826968B2 (en) 2012-09-27 2014-09-09 Apple Inc. Cold chamber die casting with melt crucible under vacuum environment
US8833432B2 (en) 2012-09-27 2014-09-16 Apple Inc. Injection compression molding of amorphous alloys
US8858868B2 (en) 2011-08-12 2014-10-14 Crucible Intellectual Property, Llc Temperature regulated vessel
US9004151B2 (en) 2012-09-27 2015-04-14 Apple Inc. Temperature regulated melt crucible for cold chamber die casting
US9302320B2 (en) 2011-11-11 2016-04-05 Apple Inc. Melt-containment plunger tip for horizontal metal die casting
US9314839B2 (en) 2012-07-05 2016-04-19 Apple Inc. Cast core insert out of etchable material
US9346099B2 (en) 2012-10-15 2016-05-24 Crucible Intellectual Property, Llc Unevenly spaced induction coil for molten alloy containment
US9445459B2 (en) 2013-07-11 2016-09-13 Crucible Intellectual Property, Llc Slotted shot sleeve for induction melting of material
US9873151B2 (en) 2014-09-26 2018-01-23 Crucible Intellectual Property, Llc Horizontal skull melt shot sleeve
US9925583B2 (en) 2013-07-11 2018-03-27 Crucible Intellectual Property, Llc Manifold collar for distributing fluid through a cold crucible

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1582533A (en) * 1976-08-03 1981-01-07 Idra Pressen Gmbh Die-casting machine
DE102008055536A1 (de) 2008-12-17 2010-07-01 Bühler Druckguss AG Verfahren zum Betreiben eines Antriebskolbens einer Druckgiessmaschine und Vorrichtung zur Durchführung des Verfahrens
JP7301192B2 (ja) * 2018-04-13 2023-06-30 芝浦機械株式会社 射出装置及び成形機
JP7057707B2 (ja) * 2018-04-13 2022-04-20 芝浦機械株式会社 射出装置及び成形機
CN114101558A (zh) * 2021-12-09 2022-03-01 松山湖材料实验室 真空铸锻一体成型装置及其使用方法

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2228973A (en) * 1937-11-11 1941-01-14 Polak Josef Die-casting machine
US2243835A (en) * 1939-06-10 1941-06-03 Western Electric Co Die casting machine
US2259781A (en) * 1935-04-29 1941-10-21 Hydraulic Press Corp Inc Hydraulic injection molding press
US2433132A (en) * 1943-12-13 1947-12-23 Lester Engineering Co Injection molding control apparatus
US2484907A (en) * 1946-10-07 1949-10-18 Hpm Dev Corp Fluid operable system
US2634468A (en) * 1948-10-16 1953-04-14 Alfred E Holder Apparatus for pressure casting
US3040399A (en) * 1960-04-22 1962-06-26 Gen Controls Co Safety control systems for machines
US3491827A (en) * 1966-07-12 1970-01-27 Die Casting Machine Tools Ltd Die casting machine with controlled injection
US3536128A (en) * 1967-02-03 1970-10-27 Corpet Louvet & Cie Injection assembly for a pressure moulding machine
US3693702A (en) * 1970-04-15 1972-09-26 Rolf Piekenbrink Pressure casting machine with pressure increase system

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4928087A (enrdf_load_stackoverflow) * 1972-07-19 1974-03-13

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2259781A (en) * 1935-04-29 1941-10-21 Hydraulic Press Corp Inc Hydraulic injection molding press
US2228973A (en) * 1937-11-11 1941-01-14 Polak Josef Die-casting machine
US2243835A (en) * 1939-06-10 1941-06-03 Western Electric Co Die casting machine
US2433132A (en) * 1943-12-13 1947-12-23 Lester Engineering Co Injection molding control apparatus
US2484907A (en) * 1946-10-07 1949-10-18 Hpm Dev Corp Fluid operable system
US2634468A (en) * 1948-10-16 1953-04-14 Alfred E Holder Apparatus for pressure casting
US3040399A (en) * 1960-04-22 1962-06-26 Gen Controls Co Safety control systems for machines
US3491827A (en) * 1966-07-12 1970-01-27 Die Casting Machine Tools Ltd Die casting machine with controlled injection
US3536128A (en) * 1967-02-03 1970-10-27 Corpet Louvet & Cie Injection assembly for a pressure moulding machine
US3693702A (en) * 1970-04-15 1972-09-26 Rolf Piekenbrink Pressure casting machine with pressure increase system

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2505648A1 (de) * 1974-02-12 1975-08-14 Toshiba Machine Co Ltd Einspritzvorrichtung fuer spritzgussmaschinen
US4019561A (en) * 1974-02-12 1977-04-26 Toshiba Kikai Kabushiki Kaisha Injection apparatus for die cast machines
US4147200A (en) * 1977-07-11 1979-04-03 Ford Motor Company Method and apparatus for eliminating entrapped gas in die castings
US5119866A (en) * 1988-09-30 1992-06-09 Ube Industries, Ltd. Method and apparatus for controlling a casting process by controlling the movement of a squeezing plunger
US5207267A (en) * 1990-08-09 1993-05-04 Toshiba Kikai Kabushiki Kaisha Injection control method of die cast machine
US5365999A (en) * 1992-06-05 1994-11-22 Maschinenfabrik Mueller-Weingarten Ag Method for the process control of a pressure diecasting machine and an apparatus for carrying out the method
US8459331B2 (en) 2011-08-08 2013-06-11 Crucible Intellectual Property, Llc Vacuum mold
US8858868B2 (en) 2011-08-12 2014-10-14 Crucible Intellectual Property, Llc Temperature regulated vessel
US8813818B2 (en) 2011-11-11 2014-08-26 Apple Inc. Melt-containment plunger tip for horizontal metal die casting
US9302320B2 (en) 2011-11-11 2016-04-05 Apple Inc. Melt-containment plunger tip for horizontal metal die casting
US9314839B2 (en) 2012-07-05 2016-04-19 Apple Inc. Cast core insert out of etchable material
US8701742B2 (en) 2012-09-27 2014-04-22 Apple Inc. Counter-gravity casting of hollow shapes
US9649685B2 (en) 2012-09-27 2017-05-16 Apple Inc. Injection compression molding of amorphous alloys
US8813816B2 (en) 2012-09-27 2014-08-26 Apple Inc. Methods of melting and introducing amorphous alloy feedstock for casting or processing
US8826968B2 (en) 2012-09-27 2014-09-09 Apple Inc. Cold chamber die casting with melt crucible under vacuum environment
US8833432B2 (en) 2012-09-27 2014-09-16 Apple Inc. Injection compression molding of amorphous alloys
US9254521B2 (en) 2012-09-27 2016-02-09 Apple Inc. Methods of melting and introducing amorphous alloy feedstock for casting or processing
US9004149B2 (en) 2012-09-27 2015-04-14 Apple Inc. Counter-gravity casting of hollow shapes
US9004151B2 (en) 2012-09-27 2015-04-14 Apple Inc. Temperature regulated melt crucible for cold chamber die casting
US9238266B2 (en) 2012-09-27 2016-01-19 Apple Inc. Cold chamber die casting with melt crucible under vacuum environment
US8813813B2 (en) 2012-09-28 2014-08-26 Apple Inc. Continuous amorphous feedstock skull melting
US9101977B2 (en) 2012-09-28 2015-08-11 Apple Inc. Cold chamber die casting of amorphous alloys using cold crucible induction melting techniques
US8813817B2 (en) 2012-09-28 2014-08-26 Apple Inc. Cold chamber die casting of amorphous alloys using cold crucible induction melting techniques
US8813814B2 (en) 2012-09-28 2014-08-26 Apple Inc. Optimized multi-stage inductive melting of amorphous alloys
US9346099B2 (en) 2012-10-15 2016-05-24 Crucible Intellectual Property, Llc Unevenly spaced induction coil for molten alloy containment
US9810482B2 (en) 2012-10-15 2017-11-07 Apple Inc. Inline melt control via RF power
US9841237B2 (en) 2012-10-15 2017-12-12 Crucible Intellectual Property, Llc Unevenly spaced induction coil for molten alloy containment
US10197335B2 (en) 2012-10-15 2019-02-05 Apple Inc. Inline melt control via RF power
US9445459B2 (en) 2013-07-11 2016-09-13 Crucible Intellectual Property, Llc Slotted shot sleeve for induction melting of material
US9925583B2 (en) 2013-07-11 2018-03-27 Crucible Intellectual Property, Llc Manifold collar for distributing fluid through a cold crucible
US10857592B2 (en) 2013-07-11 2020-12-08 Crucible Intellectual Property, LLC. Manifold collar for distributing fluid through a cold crucible
US9873151B2 (en) 2014-09-26 2018-01-23 Crucible Intellectual Property, Llc Horizontal skull melt shot sleeve

Also Published As

Publication number Publication date
JPS518097B1 (enrdf_load_stackoverflow) 1976-03-13
DE2165325A1 (de) 1972-07-27

Similar Documents

Publication Publication Date Title
US3731727A (en) Pressure intensifying apparatus for a die casting machine
US4208879A (en) Injection molding machines
US5246646A (en) Injection molding method
US4660620A (en) Arrangement for controlling an injection process of a die casting machine
US3491827A (en) Die casting machine with controlled injection
US20040099399A1 (en) Die casting machine
JP7727967B2 (ja) ダイカスト製造方法及び装置並びに加圧手段
US4019561A (en) Injection apparatus for die cast machines
DE3501846C2 (enrdf_load_stackoverflow)
US3323421A (en) Control for hydraulic actuator
JP2024177576A (ja) 加圧ロッドの動作制御方法、ダイカスト法
JPH0375259B2 (enrdf_load_stackoverflow)
US3702154A (en) Continuous casting machine reciprocation and withdrawal control system
JP7546469B2 (ja) ダイカストマシン
JP2783503B2 (ja) ダイカスト鋳造機の給湯方法およびダイカスト鋳造機
US2620528A (en) Die casting machine
JP2678933B2 (ja) 射出成形装置
JPH02151358A (ja) 真空ダイカスト装置
JPH06142884A (ja) ダイカストマシンの射出装置
US3209418A (en) Die-casting machines
JP4054231B2 (ja) 射出機用制御弁
KR100369591B1 (ko) 다이캐스팅머신의 사출실린더장치
KR102844830B1 (ko) 용탕 입구 채널에 차단 밸브가 있는 다이주조 기계 및 작동 방법
JP3009824B2 (ja) ダイカスト鋳造機
US11819911B2 (en) Die-casting machine and operating method