Horizontal column of a die-casting machine, die-casting machine and manufacturing method

Abstract

A die-casting machine (100) for making semi-finished products made of aluminium or alloys thereof or other metals comprises horizontal columns (110). Each horizontal column (110) is fixed to a first fixed surface (104) and is supported by a second fixed surface (106) and has a shaped segment (114). Locking devices (131) engageable with the shaped segment (114) are also provided to lock the moving surface (108) in the machine closing configuration. At least one of the horizontal columns (110) comprises a guide segment (110a) and a locking segment (110b) alongside the guide segment (110a). The two segments are joined by mechanical joining means, and the guide segment (110a) is structurally and / or materially configured to withstand smaller loads than the locking segment (110b).

Description

Horizontal column of a die-casting machine , die-casting machine and manufacturing method DESCRIPTIONTechni cal fi eld

[0001] The present invention pertains to the field of diecasting machines , in particular for die-casting of aluminium or aluminium alloys or other metals . In particular, the subj ect matter o f the present invention is an innovative hori zontal column and a die-casting machine equipped with said columns .Background of the Inventi on

[0002] According to solutions known today, a die-casting machine comprises a base having a predef ined longitudinal extension, on which a first fixed vertical surface and a second fixed vertical surface , longitudinally spaced apart from the first , are mounted . Moreover, the machine provides a moving vertical surface placed between the fixed surfaces , longitudinally translatable .

[0003] The two fixed vertical surfaces are connected by hori zontal columns , and the moving surface is guided on the base and supported slidingly along the hori zontal columns .

[0004] The first fixed surface carries a first hal f-mould (which is therefore a fixed hal f-mould) , and the moving surface carries a second hal f-mould (moving hal f-mould) ;the half-moulds are composed of two complementary parts which together define an impression of the piece to be obtained by die-casting.

[0005] The machine further comprises an injection unit for delivering molten metal into the mould when the two halfmoulds are coupled; the injection unit is supported by the base and placed in front of an outer face of the first fixed surface.

[0006] The movement and locking of the moving surface to the first fixed surface are usually achieved by at least one hydraulic cylinder for the movement and locking jaws which close onto the columns. Die-casting machines of such type are described, for example, in International Applications WO-A1-2022 / 195406 and W0-A1-2022 / 189991 , in the name of the Applicant.

[0007] The columns, subjected to high and cyclic stresses, are obviously crucial components, upon which the reliability of the machine depends. Usually, they are made in one piece of steel.

[0008] In the die-casting sector, the trend is to use machines of increasingly larger dimensions, in order to be able to make, in a single processing cycle, largesized and complex-shaped semi-finished pieces. This results in increasingly larger die-casting machines, characterised by an increase in the mould closing forcesand consequently an increase in the stresses acting on the columns and on the other structural components . In order to withstand static and fatigue stresses , the cross-sections and lengths of the columns are increasingly larger .

[0009] This entails considerable di f ficulty in the technological process of making and handling the columns . Obj ect of the Inventi on

[0010] The obj ect of the present invention is to identi fy an innovative column for die-casting machines , which meets the needs of the sector with regard to reliability and which overcomes the productive and logistical drawbacks mentioned above .

[0011] Said obj ect is achieved by a die-casting machine according to claim 1 . The dependent claims identi fy further advantageous embodiments of the invention .Bri ef descripti on of the Figures

[0012] The features and advantages of the die-casting machine according to the present invention wi ll be apparent from the description reported below, given by way of example and not limitation, in accordance with the figures of the accompanying drawings , in which :- figure 1 shows a die-casting machine , according to one embodiment of the present invention;- figure 2 shows an example of a hori zontal column of adie-casting machine, according to one embodiment of the present invention;- figures 3a, 3b; 4a, 4b; 5a, 5b; 6a, 6b; 7a, 7b and 8a, 8b illustrate exemplary embodiments of joining means of the horizontal column according to the present invention. Detailed description of the invention

[0013] With reference to figure 1, a die-casting machine 100 according to one embodiment of the present invention comprises a base 102 extending longitudinally, a first fixed vertical surface 104, a second fixed vertical surface 106 longitudinally spaced apart from the first fixed surface 104, and a moving vertical surface 108, placed between the fixed surfaces 104, 106 and horizontally translatable upon command.

[0014] The two fixed surfaces 104, 106 are joined by horizontal columns 110 extending longitudinally; the moving surface 108 is guided on the base 102 and slidingly supported by the horizontal columns 110 to perform a longitudinal movement towards and away from the first fixed surface 104.

[0015] An inner face 104a of the first fixed surface 104 carries a first half-mould (or fixed half-mould) ; an inner face 108a of the moving surface 108, facing the inner face 104a of the first fixed surface 104, carries a moving half-mould. The two half-moulds consist ofcomplementary parts which, when coupled, form a mould impression corresponding to the shape of the piece to be obtained by die-casting .

[0016] The machine 100 further comprises an inj ection unit 120 for delivering molten metal into the mould impression when the mould is closed .

[0017] The machine 100 further comprises at least one hydraulic cylinder 130 , for example arranged to pass through the second fixed surface 106 and fixed to it , connected to the moving surface 108 to move it longitudinally, and locking devices 131 for locking the moving surface 108 in the engaged position with the first fixed surface 104 , in which the mould is closed .

[0018] For example , said locking devices 131 comprise locking aws 132 , generally one for each column, placed on board the moving surface 108 ; preferably, moreover, said locking j aws 132 are operated by actuators , for example hydraulic .

[0019] Each hori zontal column 110 extends longitudinally along a respective column axis X between a first end 110 ' , fixed to the first fixed surface 104 , and a second end 110 ' ' , supported by the second fixed surface 106 . At the first end 110 ' , the hori zontal column 110 has a threaded segment 112 or a plurality of circumferential ribs , radially protruding and axially spaced,interspersed with grooves , as described in InternationalApplication W0-A1-2022 / 189991 , in the name of the Applicant .

[0020] Moreover, each hori zontal column 110 presents , in an intermediate position between the first end 110 ' and the second end 110 ' ' , a shaped segment 114 on which the locking j aws 132 close for the closing of the mould by radial locking .

[0021] For example , each shaped segment 114 comprises a plurality of protruding circumferential ribs 116 , spaced longitudinally, so as to form respective circumferential grooves 118 .

[0022] According to the invention, a column 110 comprises a guide segment 110a and a locking segment 110b, having structural and / or material mechanical characteristics di f ferent from one another, arranged longitudinally alongside and integrally j oined by mechanical j oining means .

[0023] In particular, the locking segment 110b, which preferably comprises at least a portion of said shaped segment 114 , is structurally and / or materially conf igured to exhibit high tensile strength, since , when the machine is in the closed configuration, it is enclosed between the first fixed surface 104 and the shaped segment 114 and is subj ected to high mechanical tension necessary tokeep the mould closed .

[0024] The guide segment 110a, on the other hand, is enclosed between the end of the shaped segment 114 and the second fixed surface 106 and is structurally and / or materially configured to withstand the cyclic tensi le and compressive forces generated during the movement phases of the moving surface to and from the first fixed surface .

[0025] The Applicant has found that such forces are signi ficantly lower than the stresses generated during the mould closing phase to which the locking segment 110b is subj ected .

[0026] For example , a usual 1650t press provides an axial load of 4000 KN on the locking segment and 200 KN on the guide segment ; a usual 4400t press provides an axial load of 11000 KN on the locking segment and 500 KN on the guide segment .

[0027] For example , the locking segment 110b has a solid cross-section, that is , a section obtained on a plane orthogonal to the column axis X . Preferably, said locking segment is obtained by forging . Preferably, moreover, the locking segment is entirely made of a high-strength steel , typically an alloy steel , for example Ni-Cr-Mo or Cr-Mo .

[0028] Preferably, on the other hand, the guide segment110a is at least partially axial ly hollow, that is , it has an annular section; preferably, the guide segment 110a is hollow along its entire length . Preferably, moreover, the guide segment is made of a structural steel , typically a non-alloy steel , for example of type S275JR or S355JR (EN 10025-2 ) .

[0029] Advantageously, said mechanical j oining means ensure a high degree of coaxiality between the two cylindrical segments . In this way, the locking segment 110b also acts as a guide for the movement of the moving surface , which is slidingly supported by the columns in the segment before and after the shaped segment 114 .

[0030] According to one embodiment of the invention, the j oining means comprise a plurality of tabs 134 , for example radial , for the mechanical connection of one end 110a ' of the guide segment 110a and one end 110b ' of the locking segment 110b ( figures 3a and 3b) .

[0031] According to a further embodiment , the j oining means comprise a threaded connection 136 between the end 110a ' of the guide segment 110a and the end 110b ' of the locking segment 110b ( figures 4a and 4b) .

[0032] According to yet another embodiment , the j oining means comprise a plurality of screws 138 , for example axial , for the mechanical connection of the end 110a ' of the guide segment 110a and the end 110b ' of the lockingsegment 110b ( figures 5a and 5b ) .

[0033] According to a further embodiment , the j oining means comprise a weld 139 between the end 110a ' of the guide segment 110a and the end 110b ' of the locking segment 110b ( figures 6a and 6b ) , preferably followed by a finishing machining of the welded column .

[0034] According to yet another embodiment , the j oining means comprise a j oint element 140 adapted to be connected to the end 110a ' of the guide segment 110a and to the end 110b ' of the locking segment 110b ( figures 7a and 7b and figures 8a and 8b ) , for example by means of axial screws or by means of axial screws and radial tabs , in order to increase the contact surface of the tabs , reducing the stresses and using lower thicknesses for the guide segment 110a .

[0035] Innovatively, the die-casting machine according to the present invention meets the needs of the sector, as it allows the making of machines of considerable dimensions , and overcomes the drawbacks mentioned above , as it makes it possible to contain production costs , makes mechanical machining and any heat and / or surface treatments more accessible , while maintaining high reliability of the critical components .

[0036] Moreover, advantageously, the invention simpli fies the handling and transport of the columns , which are nolonger constrained by the total length of the column, as it is separable into two segments . Consequently, the overall si ze of the component is reduced ( except for the welded solution) .

[0037] Furthermore , in order to carry out the mould change operation, it is usually necessary to extract one or more columns to free the space between the moving surface and the first fixed surface . In this way, suf ficient space is obtained to remove or introduce the mould .

[0038] Especially in high-tonnage die-casting machines , the column tends to tilt in the maximum extraction configuration due to its own weight . Advantageously, the present invention allows a signi ficant reduction in the total weight of the column and in particular allows shi fting the centre of gravity towards the moving surface , reducing its tilt in the fully extracted configuration .

[0039] It is clear that a person skilled in the art , in order to meet contingent needs , could make modi fications to the column and the machine described above , all of which fall within the scope of protection as defined by the following claims .

[0040] According to a variant embodiment , finally, a hori zontal column provides a guide segment 110a and a locking segment 110b, made separately from each other andmechanically j oined; preferably, the guide segment 110a is structurally and / or materially configured to withstand smaller stresses as compared with the locking segment 110b . For example , the locking segment 110b is made by forging . For example , the guide segment 110a is also made by forging .

Claims

CLAIMS1. A horizontal column (110) for a die-casting machine for making semi-finished products made of aluminium or alloys thereof or other metals, comprising:- a shaped segment (114) configured to be engaged by a locking device (131) of the machine in the machine closing configuration;- a locking segment (110b) , configured to be enclosed, in the machine closing configuration, between a moving surface (108) of the machine and the shaped segment (114) ;- a guide segment (110a) , configured to be enclosed, in the machine closing configuration, between the shaped segment (114) and a fixed surface (106) of the machine, longitudinally alongside the locking segment;- mechanical joining means to integrally join the guide segment (110a) and the locking segment (110b) , wherein the guide segment (110a) is structurally and / or materially configured to withstand smaller stresses as compared with the locking segment (110b) .

2. A horizontal column according to claim 1, wherein the locking segment (110b) has a solid cross-section.

3. A horizontal column according to claim 1 or 2, wherein the locking segment (110b) is made of alloy steel .

4. A horizontal column according to any one of the preceding claims, wherein the guide segment (110a) is at least partially axially hollow.

5. A horizontal column according to any one of the preceding claims, wherein the guide segment (110a) is made of non-alloy steel.

6. A horizontal column according to any one of the preceding claims, wherein the joining means comprise a plurality of radial tabs or a plurality of screws.

7. A horizontal column according to any one of the preceding claims, wherein the joining means comprise a threaded connection or a weld.

8. A horizontal column according to any one of claims 1 to 5, wherein the joining means comprise a joint element (140) adapted to be connected to one end (110a' ) of the guide segment (110a) and to one end (110b' ) of the locking segment (110b) .

9. A die-casting machine (100) for making semi-finished products made of aluminium or alloys thereof or other metals, comprising:- a first fixed vertical surface (104) , a second fixed vertical surface (106) longitudinally spaced apart from the first fixed surface (104) , and a moving vertical surface (108) , placed between the fixed surfaces (104,106) and horizontally translatable upon commandtherebetween;- a locking device (131) for locking the machine in the closing configuration;- at least one horizontal column (110) according to any one of the preceding claims; wherein said horizontal column is adapted to slidingly guide the moving surface (108) , is fixed to the first fixed surface (104) , and is supported by the second fixed surface (106) .

10. A die-casting machine according to claim 9, wherein said locking device (131) comprises locking jaws (132) , wherein each locking aw (132) is on board the moving surface (108) and is configured to interact with said horizontal column (110) .

11. A method of manufacturing a horizontal column (110) for a die-casting machine for semi-finished products made of aluminium or alloys thereof or other metals, comprising the steps of:- making a locking segment (110b) for the horizontal column (110) ;- making a guide segment (110a) for the horizontal column (110) , separately from the locking segment (110b) , structurally and / or materially configured to withstand smaller stresses as compared with the locking segment(110b) ;- mechanically joining the locking segment (110b) to the guide segment (110a) , arranging them longitudinally side by side, for example coaxially.

12. A manufacturing method according to claim 11, wherein the locking segment (110b) is made by forging.

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