US3700765A - Method for keeping metal mold in a clamped state - Google Patents

Method for keeping metal mold in a clamped state Download PDF

Info

Publication number
US3700765A
US3700765A US145385A US3700765DA US3700765A US 3700765 A US3700765 A US 3700765A US 145385 A US145385 A US 145385A US 3700765D A US3700765D A US 3700765DA US 3700765 A US3700765 A US 3700765A
Authority
US
United States
Prior art keywords
mold
hydraulic cylinders
halves
accumulator
pistons
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
US145385A
Other languages
English (en)
Inventor
Katashi Aoki
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Application granted granted Critical
Publication of US3700765A publication Critical patent/US3700765A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • B29C45/64—Mould opening, closing or clamping devices
    • B29C45/67—Mould opening, closing or clamping devices hydraulic
    • B29C45/6764—Mould opening, closing or clamping devices hydraulic using hydraulically connectable chambers of the clamping cylinder during the mould opening and closing movement

Definitions

  • ABSTRACT A method and device for keeping metal mold in a clamped state characterized in that the mold-halves of the metal mold are respectively coupled to a plurality of hydraulic cylinders and pistons, the mold-halves are forced to close so that the displacement of the pistons causes a hydraulic fluid to flow from one space to the other in the hydraulic cylinders and also to an accumulator through a control valve, and upon the completion of the closure, shifting the control valve to another position so that the remaining fluid in the above mentioned one space is further evacuated to another accumulator at a lowpressure with the simul- ?taneous communication maintained between the other .space of the hydraulic cylinders and the first accumulator, whereby a pressure difference is created between the two spaces separated by the pistons, and the mold-halves are thereby clamped.
  • Kp-M HI /7oki METHOD FOR KEEPING METAL MOLD IN A CLAMPED STATE This invention relates to a method and device for clamping metal mold used in the formation ofsynthetic resin and in the die-casting.
  • the metal mold provided in the conventional synthetic resin forming machine or the like has been so constructed that the both halves of the metal mold are respectively attached to a stationary plate and a movable plate of the mold clamping mechanism, the mold halves being closed by the outer force exerted to the movable plate, and are then clamped in the closed state.
  • a set of metal molds-provided in the conventional rotary type forming machine have been mounted on a pair of upper and lower rotating plates provided in the mold clamping device, and are so constructed that the mold closure and clamping are attained by the outer force applied to the movable metal mold side although the metal mold can be shifted in its closed state.
  • the metal mold or molds are always combined with the mold clamping device, and the metal molds cannot be clamped without the mold clamping device nor be kept in the clamped state without a pressing device acting on the metal molds from outside.
  • a primary object of the present invention is to be provided a method and device for maintaining the metal molds in a clamped condition without the pressing device acting on the metal molds from outside.
  • Another object of the present invention is to provide a method and device for maintaining the metal mold in a clamped and pressurized condition while the metal mold filled with a synthetic resin or a die-casting material is shifted to a mold opening-or-closing device.
  • Still another object of the present invention is to provide a method and device for keeping the metal mold in a clamped and pressurized condition in such a manner that the opening of the metal mold is not possible unless a hydraulic pressure acting on the pistons in a plurality of hydraulic cylinders coupled to the metal mold is removed.
  • a method for keeping the metal mold in a clamped and pressurized condition which comprises the steps of preparing a plurality of hydraulic cylinders and pistons included therein to be coupled to the moldhalves respectively, forcing to close the mold for displacing the pistons in the hydraulic cylinders and shifting the hydraulic fluid from a space to another space in the cylinder and also to an accumulator, and shifting a control valve to another position for evacuating the hydraulic fluid remaining in one of the spaces to another accumulator at a low pressure and for causing a pressure difference acting on the pistons.
  • a device for practicing the above described method comprising a plurality of hydraulic cylinders including pistons, a pair of base plates coupled to the hydraulic cylinders and the pistons respectively, a pair of mold-halves mounted on the confronting surfaces of the base plates, hydraulic oil paths for passing the hydraulic oil in one of the spaces in each of the hydraulic cylinders to the other under the action of the piston moved by an outer force and also to an accumulator,
  • FIG. 1 is a front view, partially in section, of a device for keeping the metal mold in a clamped state, which constitutes an embodiment of the present invention
  • FIG..2 is'a view similar to FIG. 1 of the same device wherein the metal mold is closed;
  • FIG. 3 is a partial view of the same device wherein the metal mold is going to be closed.
  • FIG. 4 is a partial view of the same device wherein the metal mold is going to be opened.
  • a male mold-half 1 and a female mold-half 2 are respectively mounted on base plates 3 and 4.
  • ders 5, 5 are fixed to the base plate 4 at tube portions 8, 8, of the hydraulic cylinders, so that the two moldhalves 1 and 2 may be thereby open-or-closed freely.
  • the upper part and the lower part of the hydraulic cylinders 5, 5, are connected to hydraulic oil paths 9 for flowing the operative oil caused by the displacement of the pistons 6, 6, inside of the hydraulic cylinders 5, 5.
  • the hydraulic oil paths 9 are composed of a bladder type accumulator 10 for storing one part of the operative fluid pushed out of the cylinders 5, 5, by means of the pistons 6, 6, and for supplying the operative fluid to the cylinders 5, 5, when it is desired, another bladder type accumulator 11 and a check valve 15 for evacuating a part of the operative fluid from the lower space in each of the hydraulic cylinders 5, 5, and thereby reducing the pressure in the lower space of the cylinder 5, 5, and a valve means 12 which may be transferred between a first position and a second position for controlling the flow of the operative fluid.
  • numerals 13 and 14 designate open-or-closing members for the metal mold.
  • valve means 12 of the hydraulic oil paths 9 is shifted to its pass-through position as shown in FIG. 3 and forces the male mold-half 1 on the base plate 3 down to the other mold-half 2 on the base plate 4.
  • the pistons 6, 6, are moved inside of the tubes 8, 8, of the hydraulic cylinders 5, 5, downwardly, and the operative fluid in the lower space of the hydraulic cylinders 5, 5, is pushed out of the cylinders to the upper space of the same hydraulic cylinders and also to the accumulator 10 through the valve means 12 placed at its passthrough position.
  • the amount of the fluid passed into the accumulator 10 corresponds to the difference of the volumes of the fluid pushed out of the lower space of the hydraulic cylinder and of the fluid introduced into the upper space of the same cylinder because of the existence of the piston rod 7. As a result the pressure in the accumulator 10 is elevated.
  • the mold-halves When the base plate 3 is fully descended so that the male mold-half l engages the female mold-half 2 on the base plate 4, there is no recognizable pressure difference between the upper space and the lower space of the hydraulic cylinder 5 separated by the piston 6, and since the valve means 12 is in the pass-through position (hereinafter called the first position), the mold-halves may be easily opened if an outer force is exerted on the base plate 3 upwardly as indicated by an arrow mark in FIG. 4.
  • the valve means 12 is transferred to a one port blocking position (hereinafter called the second position), asshown in FIG. 2.
  • the second position a one port blocking position
  • the hydraulic fluid remaining in the lower space of the hydraulic cylinders 5, 5 is communicated to the accumulator 11, whereby the pressure in the lower space is decreased to a lower value.
  • the upper space of the hydraulic cylinders 5, 5 is still communicated with the accumulator at a high pressure, and for this reason, a pressure difference is created between the upper space and the lower space of the hydraulic cylinders 5, 5, which urges the pistons 6, 6, downwardly.
  • valve means 12 When it is desired to open the metal mold, the valve means 12 is shifted back to its original position as shown in FlG. 4.
  • the pressure difference between the upper and lower spaces of the hydraulic cylinders 5, 5, is eliminated, and the metal mold-halves can be easily opened by raising the base plate 3 upwardly, for instance, by means of the mold opening-or-closing device.
  • the hydraulic fluid in the upper space of the hydraulic cylinders 5, 5, can be shifted back to the lower space thereof through the valve means 12 at the pass-through position.
  • the hydraulic fluid stored in the accumulators 10 and 11 is passed into the lower space of the hydraulic cylinders 5, 5, under the suction caused by the rising pistons 6, 6, whereby the whole system is brought back to its initial condition as shown in FIG. 1.
  • the metal mold thus closed is further clamped employing a plurality of hydraulic cylinders coupled to the mold-halves in a freely openable and closable manner, the metal mold can be maintained in the clamped state even after the metal mold is removed from the injection molding machine, and the metal mold can withstand the inner pressure caused by the synthetic resin filled inside of the metal mold because of the oil pressure inside of the hydraulic cylinders which can be removed only by shifting the control valve means to another position.
  • the device is constructed simply by coupling the hydraulic cylinders to the mold-halves so that the mold-halves can be freely open-or-closed through the operation of the hydraulic cylinders, and the transportation of the device is also very easy.
  • the method and the device according to the present invention can afford various advanta eo featu e such as e ablin the transportation m oldiii g which has been d1 icult l l'l the conventional apparatus.
  • a method for keeping metal mold in a clamped state during filling comprising the steps of preparing a plurality of hydraulic cylinders and pistons respectively coupled to the mold-halves, forcing to close said moldhalves so that the displacement of the pistons causes the hydraulic fluid to flow from one space to the other in said hydraulic cylinders and also to an accumulator through a control valve means, and shifting said control valve means to another position at the completion of the closure of the mold-halves so that the remaining fluid in said one space is further evacuated to another accumulator at a low pressure with the simultaneous communication maintained between the other space of the hydraulic cylinders and the first accumulator, whereby a pressure difference is created between the spaces separated by the pistons in said hydraulic cylinders, and the mold-halves are thereby clamped, and then filling the mold.

Landscapes

  • 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)
US145385A 1970-05-30 1971-05-20 Method for keeping metal mold in a clamped state Expired - Lifetime US3700765A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4668870A JPS559289B1 (cs) 1970-05-30 1970-05-30

Publications (1)

Publication Number Publication Date
US3700765A true US3700765A (en) 1972-10-24

Family

ID=12754304

Family Applications (1)

Application Number Title Priority Date Filing Date
US145385A Expired - Lifetime US3700765A (en) 1970-05-30 1971-05-20 Method for keeping metal mold in a clamped state

Country Status (6)

Country Link
US (1) US3700765A (cs)
JP (1) JPS559289B1 (cs)
CA (1) CA960822A (cs)
DE (1) DE2126761C3 (cs)
FR (1) FR2090394B1 (cs)
GB (1) GB1314160A (cs)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3746491A (en) * 1972-01-07 1973-07-17 Chicago Rawhide Mfg Co Injection molding apparatus
US4035118A (en) * 1973-08-27 1977-07-12 Macmillan Kenneth T Self-centering matrices for retreading molds
US4240778A (en) * 1979-08-27 1980-12-23 Efco, Inc. System for providing for parallelism in fluid powered press or the like
US5237916A (en) * 1992-06-18 1993-08-24 John T. Hepburn, Limited Regenerative hydraulic cylinders with internal flow paths
EP1612028A1 (de) * 2004-06-29 2006-01-04 Karl Hehl Spritzgiessmaschine mit einem Aufnahmebehältnis für ein Druckmittel
CN103291687A (zh) * 2013-06-03 2013-09-11 济南二机床集团有限公司 压力机移动工作台顶起油缸
US20140030371A1 (en) * 2011-04-12 2014-01-30 Husky Injection Molding Systems Ltd. Apparatus including pressure-control assembly for adjustment of fluid pressure between fluid-bottle assembly and hydraulic-accumulator assembly associated with molding system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT404640B (de) * 1994-02-18 1999-01-25 Engel Gmbh Maschbau Verfahren zum betätigen der schliesseinrichtung einer zweiplatten-spritzgiessmaschine

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1530770A (fr) * 1967-06-20 1968-06-28 M U C Schiffer O H G Dispositif d'actionnement hydraulique d'outils ou analogue, notamment d'éléments mobiles de moules de presses à injecter la matière plastique

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3746491A (en) * 1972-01-07 1973-07-17 Chicago Rawhide Mfg Co Injection molding apparatus
US4035118A (en) * 1973-08-27 1977-07-12 Macmillan Kenneth T Self-centering matrices for retreading molds
US4240778A (en) * 1979-08-27 1980-12-23 Efco, Inc. System for providing for parallelism in fluid powered press or the like
US5237916A (en) * 1992-06-18 1993-08-24 John T. Hepburn, Limited Regenerative hydraulic cylinders with internal flow paths
EP1612028A1 (de) * 2004-06-29 2006-01-04 Karl Hehl Spritzgiessmaschine mit einem Aufnahmebehältnis für ein Druckmittel
US20140030371A1 (en) * 2011-04-12 2014-01-30 Husky Injection Molding Systems Ltd. Apparatus including pressure-control assembly for adjustment of fluid pressure between fluid-bottle assembly and hydraulic-accumulator assembly associated with molding system
CN103291687A (zh) * 2013-06-03 2013-09-11 济南二机床集团有限公司 压力机移动工作台顶起油缸

Also Published As

Publication number Publication date
CA960822A (en) 1975-01-14
DE2126761B2 (de) 1977-07-21
GB1314160A (en) 1973-04-18
DE2126761C3 (de) 1978-03-30
FR2090394B1 (cs) 1974-04-05
FR2090394A1 (cs) 1972-01-14
DE2126761A1 (de) 1971-12-09
JPS559289B1 (cs) 1980-03-08

Similar Documents

Publication Publication Date Title
JP3455560B2 (ja) 射出成形機用型締機構
US3833330A (en) Reciprocating injection molding apparatus and mold clamping means
US3700765A (en) Method for keeping metal mold in a clamped state
US3267517A (en) Apparatus for molding hardenable plastics in a vacuum
US2490625A (en) Transfer molding press
ES482528A1 (es) Maquina de fundicion a presion.
US3418692A (en) Mold clamping apparatus
US3528134A (en) Injection molding apparatus
US4030299A (en) Intensified cylinder assembly
GB1260958A (en) Mould clamping unit for injection moulding apparatus
US3600753A (en) Differential pressure forming mold assembly for forming plastic articles in a thermoplastic web
EP0311269B1 (en) Mold clamping device
US2792592A (en) Clamping mechanism for molding machine
US4057382A (en) Apparatus for air-pressure forming thermoplastic resin sheets
US2420405A (en) Transfer molding press
US2465204A (en) Transfer molding press
US4249880A (en) Mold-closing device for an injection-molding machine
US2410909A (en) Upward acting molding press
US2657429A (en) Injection molding machine
US3801257A (en) Device for keeping metal mold halves in a clamped state
US3803842A (en) Device for keeping metal mold in a clamped state
US3768953A (en) Clamping apparatus for molding machine
US3697212A (en) Molding press
GB1489667A (en) Mould clamping apparatus for moulding machinery
US2568042A (en) Hydraulic press