Device for clamping a diecasting mould

Abstract

The present invention relates to a device (E) for clamping a die-casting mold, comprising a hydraulic cylinder (1), a cylindrical connecting shaft (2), a cylindrical clamping unit (3) which has a cross-section that changes along its longitudinal axis (L), such that the clamping unit (3) has a planar surface (3a) in one section, an anti-rotation device (4), and a lubrication system (5), characterized in that the planar surface (3a) of the clamping unit (3) has an inclination (N) towards the longitudinal axis (L) which is in the range of 1° to 12°, and the anti-rotation device (4) comprises a fixedly arranged guide rod (4a) which extends parallel to the connecting shaft (2) and clamping unit (3).The present invention further relates to a mounting plate (A, A') for a die-casting machine (D) for receiving this device, a corresponding die-casting machine (D) and a method for mounting a die-casting mold half (12a, 12b) on a mounting plate (A, A').

Description

[0001] The present invention relates to a device for clamping a die-casting mold, a clamping plate for a die-casting machine with this device, and a die-casting machine with a corresponding clamping plate.

[0002] Die-casting machines are well known (see, e.g., Brunnhuber, Praxis der Druckgussfertigung [The Practice of Die Casting], Berlin, 3rd ed. 1980). In a die-casting machine, a mold consisting of two halves is closed under high pressure, molten metal (or a metal alloy) is introduced into the closed mold, and after the casting material has cooled, the finished die-cast part can be removed by opening the mold. The mold halves are arranged on a fixed and a movable mounting plate, and the mold is closed by moving the movable mounting plate along guide columns towards the fixed mounting plate.

[0003] During die casting, considerable forces act on the machine components. Since there has been a trend in recent years, particularly in the automotive sector, towards increasingly larger structural components, there is a need for larger die casting machines with increased clamping force, preferably more than 45,000 kN.

[0004] Therefore, solutions must be used that can withstand these significantly higher forces compared to injection molding. Among other things, it must be ensured that the mold halves mounted on the clamping plates retain their position throughout the entire die-casting process.

[0005] In die casting, the clamping of mold halves onto clamping plates is usually achieved by inserting a component protruding from the mold half, for example a clamping bolt, into a designated opening in the clamping plate and detachably securing it therein.

[0006] This releasable fastening has previously been achieved by inserting a locking mechanism into the mounting plate through a laterally accessible T-slot. This locking mechanism has a fork-shaped end section that can be hydraulically moved into a position where it can engage and secure the component protruding from the mold half, such as a clamping bolt, which is inserted into the mounting plate. For reliable clamping of a mold half onto a mounting plate, several (usually 4 to 12) such locking mechanisms must be provided in the mounting plate.

[0007] This solution has disadvantages. The fork-shaped end section has a rectangular cross-section. To insert the locking mechanism into the mounting plate, the lateral opening in the side surface of the mounting plate must have a rectangular (T-shaped) groove. This groove must be milled into the mounting plate, which is more complex to manufacture and, due to the dimensions of the groove, also affects the stiffness and strength of the mounting plate, which must be made correspondingly thicker and therefore heavier.

[0008] In injection molding, it is known to use clamping wedges as a clamping mechanism for clamping and holding closed mold halves (e.g., https: / / easchangesystems.com / de / product / integrierter-hecs-keilspannzylinder / ). German patent DE 10 2008 052 950 A1, issued by Engel Austria, describes a clamping wedge system for an injection molding machine, providing clamping wedges in a further clamping mechanism for holding the mold halves together.

[0009] However, these clamping mechanisms are not designed for die-casting machines. They are relatively short and provide only limited clamping force. Therefore, they are unsuitable for the significantly larger mounting plates and the considerably greater opening forces required in die-casting (especially for machines producing larger structural components) due to the shrinkage of the component.

[0010] The object of the present invention was to provide a mechanism for clamping a mold half onto a mounting plate of a die-casting machine, which overcomes the disadvantages of the prior art described above.

[0011] The above problem is solved by the device, mounting plate and die-casting machine defined in the claims.

[0012] In detail, the present invention relates to a device (E) for clamping a die-casting mold, comprising a hydraulic cylinder with a housing and a piston movably arranged in the cylinder, to which a cylindrical piston rod is attached, a cylindrical connecting shaft whose first end is connected to the free end of the piston rod, a cylindrical clamping unit which is connected to a second end of the connecting shaft and has a cross-section that changes along its longitudinal axis (L) so that the clamping unit has a planar surface in one section, an anti-rotation device, and a lubrication system. characterized by the fact that the planar surface of the clamping unit has an inclination (N) towards the longitudinal axis (L) which is in the range of 1° to 12°, and the anti-rotation device comprises a fixed guide rod which extends parallel to the connecting shaft and clamping unit.

[0013] The device according to the invention is characterized by various features.

[0014] In contrast to the fork-shaped clamping mechanism described above, which has been used in die casting to date, the device according to the invention has a cross-section that allows it to be inserted into a circular bore. Providing a T-slot-shaped bore in a mounting plate is not necessary. This results in an advantage with regard to the required stiffness and strength of the mounting plate, which in turn offers the possibility of making the mounting plates slimmer and lighter. Furthermore, circular bores can be provided more easily and cost-effectively.

[0015] In contrast to known clamping mechanisms from the injection molding sector, the device according to the invention has a cylindrical connecting shaft. This connecting shaft can be provided in variable lengths and therefore allows the device according to the invention to be easily used in significantly longer bores than those provided for in injection molding, and in particular also in bores of different lengths.

[0016] The device according to the invention further features an anti-rotation device which reliably prevents the risk of the device rotating during a movement described below in a bore of a mounting plate from an open (unclamped) position to a closed (clamped) position, which exists due to the essentially cylindrical cross-section and the length of the device.

[0017] The device according to the invention further comprises a lubrication system. This is necessary in the die-casting area (as opposed to the injection molding area) due to the prevailing operating conditions and dimensions in order to ensure reliable operation of the device according to the invention.

[0018] Finally, the device according to the invention comprises a clamping unit which has an inclined planar surface in one section. This gives the clamping unit a wedge shape in that section. When the wedge-shaped section of the clamping unit is inserted into an opening of a clamping bolt in one mold half, which has a cross-section that allows for a wedge-shaped clamping action with the inclined planar surface of the clamping unit (i.e., has a complementary dimension), the wedge shape assists (or even forces) movement of the mold towards the mounting plate. In the closed state (i.e., when the clamping unit is inserted maximally into the opening of the clamping bolt), a clamping force is generated which ultimately secures the mold to the mounting plate in a form-fit and force-fit manner.

[0019] It has been shown according to the invention that the wedge-shaped clamping mechanisms known from the injection molding sector are unsuitable for providing the clamping forces required in the die-casting sector. In the wedge-shaped clamping mechanisms known from the injection molding sector, manufactured by Engel, the inclined surface of the clamping wedge has an angle of inclination of 15° or more and only provides a positive-locking connection of the wedge-shaped clamping mechanism in the mounting plate. Here and subsequently, the angle of inclination represents a deviation from an imaginary horizontal line that extends along the cylindrical surface of the cylindrical section of the clamping unit and parallel to the longitudinal axis of the clamping unit.

[0020] Under the conditions prevailing in die casting, a wedge-shaped clamping unit with an inclination angle of its inclined planar surface of 15° or more can no longer withstand the opening or bursting forces. It has been shown that the clamping mechanisms known from injection molding are forced out of the mounting plate under the forces applied in die casting, and the mold half is no longer reliably clamped.

[0021] It has been found according to the invention that a wedge-shaped clamping unit can be used in die-casting applications if the angle of inclination of its inclined planar surface is in the range of 1° to 12°, preferably in the range of 5° to 10°. In this range, sufficient self-locking is generated under die-casting conditions (i.e., friction-induced resistance to slippage or rotation of two adjacent bodies).

[0022] Since providing a wedge shape as described above supports or forces a movement of the shape towards the mounting plate, the angle of inclination should not fall below a lower limit defined above.

[0023] The device according to the invention is hydraulically operated and therefore comprises a hydraulic cylinder. Hydraulic cylinders are well known and do not require further description. A piston is moved within the hydraulic cylinder by means of a hydraulic medium (for example, hydraulic oil). It has been found that less force is required to operate the device according to the invention than to operate the previously conventional fork-shaped clamping device. Therefore, a smaller hydraulic cylinder can be used in the device according to the invention, resulting in cost and space advantages compared to the previously conventional fork-shaped clamping device.

[0024] According to the invention, the hydraulic cylinder has a housing known per se, with which the hydraulic cylinder can be attached, for example, to a mounting plate of a die-casting machine. Further components, described below, can also be attached to the housing. The shape and dimensions of the housing are not particularly limited. Preferably, the housing is cuboid in shape according to the invention.

[0025] In a known manner, the piston is connected to a cylindrical piston rod. The movement of the piston within the hydraulic cylinder extends or retracts the attached piston rod into the hydraulic cylinder.

[0026] A cylindrical connecting shaft is attached to the free end of the piston rod (i.e., the end not connected to the piston). The connection between the piston rod and the connecting shaft can be made in a known manner, with a detachable fastening (for example, by screws) being preferred for the purpose of easy replacement of the connecting shaft. The diameter of the cylindrical connecting shaft is slightly smaller than the diameter of the circular bore in the mounting plate described below, in order to ensure smooth movement of the device according to the invention within the bore. Preferably, according to the invention, the cylindrical connecting shaft has a larger diameter than the piston rod and at least the same diameter as the clamping unit.

[0027] The cylindrical connecting shaft can have a variable length. This allows the length of the device according to the invention to be adapted to the length of the bore in the mounting plate. This is particularly advantageous given that larger die-casting machines for producing larger structural components include correspondingly larger mounting plates, in which correspondingly longer bores must be provided. The exact length of the cylindrical connecting shaft must be selected depending on the dimensions of the mounting plate or mold frame in which the device according to the invention is to be used. The dimensions of the corresponding mounting plates are known to those skilled in the art.

[0028] A cylindrical clamping unit is attached to the free end of the cylindrical connecting shaft (i.e., the end not connected to the piston rod). The connection between the clamping unit and the connecting shaft can be made in a known manner, with a detachable fastening (for example, using screws) being preferred for the purpose of easy replacement of the connecting shaft and the clamping unit.

[0029] The clamping unit has a cross-section that varies along its longitudinal axis (L), i.e., the clamping unit is not perfectly cylindrical throughout. Rather, in one section, the clamping unit has a planar surface that is inclined (N) towards the longitudinal axis (L) of the clamping unit, with an inclination in the range of 1° to 12° and preferably 5° to 10°. This section extends to the end of the clamping unit opposite the connecting shaft. This gives the clamping unit a wedge shape in this section.

[0030] According to a preferred embodiment of the present invention, the clamping unit has an inclined planar surface as described above. In the corresponding section (in which the inclined planar surface is present), the clamping unit no longer has a circular cross-section, but rather a circular segment-shaped, preferably semicircular, cross-section.

[0031] According to the present invention, the clamping unit can also have several inclined planar surfaces as described above. For example, an inclined planar surface as described above can be located on the top and bottom of the clamping unit, whereby the clamping unit no longer has a circular cross-section in the corresponding section, but a stadium-shaped cross-section.

[0032] A stadium-shaped cross-section is defined as a cross-section consisting of a halved circle with radius r, in the center of which a rectangle of size a*2r has been inserted. The length of the rectangle a can be arbitrary.

[0033] The ratio of the lengths of the sections in the clamping unit with circular cross-section and those with a different cross-section (i.e., the ratio of the length of the cylindrical section to the length of the wedge-shaped section) is not particularly limited and can be adjusted as required. Preferably, the length of the wedge-shaped section can be 50% to 90% of the total length of the clamping unit.

[0034] The device according to the invention is made from materials that are commonly used in die casting and that can withstand the conditions of a die casting process.

[0035] The device according to the invention further features an anti-rotation device. As explained above, due to the essentially cylindrical cross-section of the device's essential components and its length, there is a risk of the device rotating during a movement described below within a bore of a mounting plate from an open (unclamped) position to a closed (clamped) position. To reliably prevent this, the device according to the invention includes, as an essential component of the anti-rotation device, a fixedly arranged guide rod extending parallel to the connecting shaft and clamping unit.

[0036] This guide rod is preferably fixed to the side surface of the hydraulic cylinder housing, from which the piston rod extends. Thus, the piston rod and guide rod extend parallel to each other into the bore in the mounting plate.

[0037] As described below, it is preferred that the bore in the mounting plate, in addition to the actual circular bore, has a bulge in a first section after the opening in the side surface of the mounting plate. While the piston rod, the connecting shaft, and the clamping unit are located and move within the circular bore, the anti-rotation device with the guide rod is arranged in the bulge next to the circular bore. Preferably, the end of the guide rod furthest from the housing is fixed in the bulge, for example, by screws.

[0038] The fixed guide rod preferably serves to guide a guide plate, which is preferably part of the anti-rotation device. This guide plate is attached to a rear end of the connecting shaft, facing away from the clamping unit. When the connecting shaft is moved hydraulically as described above, the attached guide plate moves accordingly. The guide plate has a preferably circular recess (opening) in which the guide rod is arranged. If the guide plate moves due to the hydraulic movement of the connecting shaft, this movement is forced along the guide rod. This forced restriction of movement prevents the connecting shaft connected to the guide plate, and thus also the clamping unit connected to the connecting shaft, from rotating.

[0039] The guide plate preferably has two sections, which enclose an angle of preferably 90°. The first section of the guide plate has the above-described, preferably circular, recess (opening) in which the guide rod is arranged. This section runs essentially parallel to the rear end of the connecting shaft.

[0040] The second, angled section extends laterally alongside the guide rod and is preferably movably arranged on one side of the hydraulic cylinder housing. For example, a rail can be provided on one side of the hydraulic cylinder housing in which the relevant section of the guide plate can move.

[0041] The guide plate can also be used, preferably, to guide a line of a lubrication system to the connecting shaft. This is described below.

[0042] The device according to the invention further comprises a lubrication system. As explained above, this is necessary in the die-casting area (as opposed to the injection molding area) due to the prevailing operating conditions and dimensions in order to ensure a defined state in the joint and thus reliable operation of the device according to the invention.

[0043] According to the invention, it is necessary to remove as many dirt particles as possible to prevent the wedge-shaped clamping unit from jamming. For this purpose, at least one outlet opening of a lubricant line is arranged in the clamping unit to introduce lubricant directly into the space in which the clamping unit is moved. Preferably, the at least one outlet opening is located in the cylindrical section of the clamping unit, near the inclined planar surface. Preferably, according to the invention, two outlet openings are located on opposite sides of the cylindrical section of the clamping unit, near the inclined planar surface.

[0044] The at least one outlet opening in the clamping unit is connected via a lubricant line to a lubricant reservoir, for example, a lubricant tank. This line preferably runs inside the connecting shaft and the clamping unit to avoid impeding the movement of these components. The line enters the connecting shaft at the end furthest from the clamping unit.

[0045] As already explained above, according to the invention, the guide plate can advantageously be used to guide the line of a lubrication system to the connecting shaft. For this purpose, the line can be arranged on the guide plate and thus guided to the position where the guide plate is located on the connecting shaft, and then inserted into the connecting shaft.

[0046] According to a preferred embodiment of the present invention, the device according to the invention further comprises end-position monitoring. Preferably, sensors such as inductive sensors are arranged on the housing of the hydraulic cylinder for this purpose. Preferably, the sensors are arranged on one side of the housing, namely the side on which the guide plate is also arranged. Preferably, one sensor is arranged at the front lateral end and one sensor at the rear lateral end of this side of the housing. A lateral end is understood here to be a region located in the respective third, preferably a quarter, particularly preferably a fifth, that adjoins the corresponding end of the housing. According to the invention, the sensors are designed such that the guide plate can interact with a sensor when it is in a position in front of the sensor.For example, the guide plate can have a closing section that extends downwards along the side of the housing. If this closing section is pushed over a sensor when the guide plate is moved, the sensor is triggered.

[0047] Since the guide plate moves together with the connecting shaft and the clamping unit as described above, the position of the guide plate, preferably its end section as described above, is an indicator of the position of the connecting shaft and the clamping unit. When the connecting shaft and the clamping unit are retracted, the guide plate is also in a retracted position and triggers the sensor at the rear side end of the housing. When the connecting shaft and the clamping unit are hydraulically extended, the guide plate also moves into an extended position and triggers the sensor at the front side end of the housing.

[0048] Die-casting machines are well known and do not need to be described in detail here. These machines produce molded parts in a mold, which typically consists of two mold halves that together define the outer contours of the part to be produced. Each molded part, usually one mold half, is located on a fixed platen and a movable platen.

[0049] According to the invention, the die-casting machine is preferably a two-plate die-casting machine or a three-plate die-casting machine, preferably a two-plate die-casting machine. These types of die-casting machines are well known. The applicant manufactures, among other things, two-plate die-casting machines under the trade name CARAT®.

[0050] WO 2008 / 131571 A1 describes an example of a horizontal two-platen die-casting machine. This two-platen die-casting machine comprises a movable mounting plate (BAP) and a fixed mounting plate (FAP), each supporting one mold half. The die-casting mold can be opened and closed by moving the movable mounting plate on a machine bed via force transmission means. In the closed position, the two mounting plates are pressed firmly together, so that the two mold halves form a closed hollow mold. Molten metal is introduced into the closed mold under pressure and cooled as it solidifies. After opening the mold (by moving the movable mounting plate), the solidified casting can be removed by ejection using an ejector.The movement of the movable mounting plate in the machine is carried out according to WO 2008 / 131571 A1 via guide columns, preferably 4 guide columns.

[0051] Material for producing the desired part can be introduced into the formed hollow (casting) mold (also called cavity or mold contour). In die casting, this material consists of molten metals, such as aluminum or molten metal alloys, which are forced under pressure into the mold through a pouring opening in the fixed mounting plate using a casting cylinder of a casting unit. To prevent the mold from opening under these stressful conditions, the movable mounting plate is held in its closed position by a locking cylinder and clamping cylinders attached to the guide columns.

[0052] Once the material has solidified in the mold, the mold is opened by moving the movable mounting plate in the opening direction, and the finished part can be removed. For example, the finished cast component can be ejected using ejectors.

[0053] A distinction is made between cold-chamber and hot-chamber die-casting machines. In a hot-chamber die-casting machine, the casting hopper of a casting unit is held in a crucible containing molten metal. A ram moves into the hopper and forces the molten metal through a casting chamber (also at least partially located in the crucible) and a pouring opening in the fixed mounting plate into the mold. In this process, the hopper and ram are continuously exposed to the molten metal. The casting unit of a hot-chamber die-casting machine is fundamentally different in design from that of a cold-chamber die-casting machine. In a cold-chamber die-casting machine, the metal is melted or kept warm in a molten state in a separate device.The amount of molten metal required to produce the desired component is poured into a cold casting chamber of a casting unit via a filling opening and pressed into the mold through a casting opening provided in the fixed mounting plate by means of a casting piston movably arranged in the casting chamber.

[0054] Cold chamber and hot chamber die-casting machines are well known to experts.

[0055] According to the invention, the front of the mounting plates has a substantially square shape. The receiving openings for the guide columns are arranged in the corners of the front. Depending on the size of the die-casting machine, molds of various sizes can be used. The clamping force provided by the die-casting machine and the mold bursting force occurring in the mold during the casting process must be taken into account. To prevent deformation of the mold during the casting process, the mold must have a defined minimum length and width. These dimensions depend on the dimensions of the die-casting machine and cannot be specified generally.

[0056] One half of the mold is clamped (fixed) onto the fixed mounting plate and the other onto the movable mounting plate. In this context, "one half of a mold" means that the mold is composed of two parts. These parts do not necessarily each constitute 50% of the entire mold. For the purpose of fixing the mold halves, they preferably have a component protruding from the mold half, for example, a clamping bolt. However, other fastening means such as screws or clamping jaws can also be used. While in injection molding, providing very few (usually 2 to 4) such clamping bolts is sufficient to clamp one mold half, in die casting, more (usually 2-10, preferably 4-8, particularly preferably 8) such clamping bolts are provided on one mold half for reliable clamping of a mold half onto a mounting plate.Preferably, the clamping bolts are arranged symmetrically, so that, for example, two rows of four clamping bolts each are arranged parallel on one side of a mold half.

[0057] According to the invention, the clamping bolts are designed such that the opening of the clamping bolt has a cross-section which, in the closed position of the clamping unit, enables a wedge-shaped clamping action with the inclined planar surface of the clamping unit. As explained above, the design of the opening of a clamping bolt of a mold half, such that it enables a wedge-shaped clamping action with the inclined planar surface of the clamping unit of the device according to the invention (i.e., it has a complementary dimension), supports (or even forces) a movement of the mold towards the mounting plate.

[0058] In other words, the opening of the clamping bolt preferably includes a similarly inclined planar surface. The inclination and dimensions of the planar surface in the opening of the clamping bolt correspond to the inclination and dimensions of the planar surface of the clamping unit.

[0059] According to the invention, the opening of the clamping bolt is preferably a through bore with a stadium-shaped cross-section (in the case that the clamping unit has an inclined planar surface as described above on the top and bottom of the clamping unit) or with a circular segment-shaped, preferably semicircular, cross-section (in the case that the clamping unit has an inclined planar surface as described above only on the top of the clamping unit).

[0060] The mounting plate, preferably the fixed and the movable mounting plate, has complementary openings into which these clamping bolts can be inserted.

[0061] Each of these openings is connected to a bore that extends from an opening in a side surface of the mounting plate to the opening for receiving the clamping bolt.

[0062] The present invention therefore also relates to a mounting plate for a die-casting machine, comprising a front, a back and side surfaces, wherein the front has at least one opening for receiving a clamping bolt of a die-casting mold half, wherein the opening for receiving the clamping bolt is connected to a bore which extends from an opening in a side surface of the mounting plate to the opening for receiving the clamping bolt, characterized in that the bore has a circular cross-section.

[0063] A device according to the present invention is arranged in at least one, preferably in each, bore of the mounting plate.

[0064] According to the present invention, the mounting plate can be a fixed or a movable mounting plate. Particularly preferred are all mounting plates of a die-casting machine mounting plates according to the invention.

[0065] The present invention further relates to a die-casting machine comprising at least one mounting plate according to the present invention.

[0066] The present invention further relates to a method for clamping a die-casting mold half onto a clamping plate for a die-casting machine according to the present invention, comprising the steps of: a) Inserting a clamping bolt, which is arranged on a front side of the die-casting mold half, into the opening of the mounting plate to receive the clamping bolt, b) Moving the clamping unit of the device located in the bore of the mounting plate according to the present invention in the presence of a lubricant by hydraulic actuation of the hydraulic cylinder from an open position to a closed position, wherein the clamping unit in the closed position is inserted into an opening of the clamping bolt, wherein the opening of the clamping bolt has a cross-section which, in the closed position of the clamping unit, enables a wedge-shaped clamping with the inclined planar surface of the clamping unit.

[0067] As described above, the clamping unit is retracted when the piston in the hydraulic cylinder is at the end furthest from the bore. In this position, the clamping unit is not located in the opening of the clamping bolt. This position is referred to as the open or unclamped position. In the open position, the corresponding clamping bolt can be removed from the mounting plate. If all clamping units of the clamping devices located in the mounting plate are in the open position, the mold half can be removed from the mounting plate and, for example, replaced.

[0068] On the other hand, the clamping unit is fully extended when the piston in the hydraulic cylinder is at the end facing the bore. In this position, the clamping unit is located in the opening of the clamping bolt. This position is referred to as the closed or clamped position. In the closed position, the clamping bolt cannot be removed from the mounting plate. The mold half cannot be removed from the mounting plate.

[0069] According to a preferred embodiment of the present invention, the movement of the guide plate is detected by sensors arranged on the housing of the hydraulic cylinder, preferably one sensor each at the front lateral end and at the rear lateral end of the housing, wherein the guide plate interacts with a sensor when it is in a position in front of the sensor. In this way, as described above, it can be determined whether the clamping unit is in an open (untensioned) or a closed (tensioned) position.

[0070] The present invention is explained in more detail below with reference to preferred embodiments and non-limiting drawings. These show: Fig. 1 is a schematic representation of an embodiment of the mold clamping device according to the invention. Fig. 2 is a sectional view of an embodiment of the mold clamping device according to the invention. Fig. 3 is a schematic representation of an embodiment of the end position monitoring of the mold clamping device according to the invention. Fig. 4 is a schematic representation of an embodiment of the lubrication system of the mold clamping device according to the invention. Fig. 5 is a schematic representation of an embodiment of a mounting plate according to the invention. Fig. 6 is a schematic representation of an embodiment of a bore provided in the mounting plate according to the invention. Fig. 7 is a side view of a die-casting machine D according to an embodiment of the present invention. Fig. 8a is a sectional view of an embodiment of the mold clamping device according to the invention in an open or unclamped position.Fig. 8: Sectional view of an embodiment of the mold clamping device according to the invention in a closed or clamped position. Fig. 9a: Schematic representation of an embodiment of a clamping bolt in an open or unclamped position of the mold clamping device according to the invention. Fig. 9b: Schematic representation of an embodiment of a clamping bolt in a closed or clamped position of the mold clamping device according to the invention.

[0071] The same reference symbols in different figures denote the same components.

[0072] In Fig. 1 Figure 1 shows a schematic representation of an embodiment of the mold clamping device E according to the invention. A hydraulic cylinder 1 is arranged in a cylinder housing 1a. The cylinder housing 1a comprises a front and a rear, each with a rectangular cross-section, which are connected to each other by rods. A cylinder piston 1b (not visible here) is arranged in the hydraulic cylinder 1 and can be moved forwards and backwards within the hydraulic cylinder 1 by hydraulic fluid. The hydraulic fluid is supplied to the hydraulic cylinder 1, which is designed here as a double-acting cylinder, through hydraulic connections 1d and 1e, which are arranged laterally on the cylinder housing 1a and open into the front and rear sections of the hydraulic cylinder 1, respectively. A piston rod 1c is arranged on the cylinder piston 1b and extends through the front of the cylinder housing 1a.

[0073] The piston rod 1c is connected to a connecting shaft 2, preferably detachably (for example, via a screw connection). The cylindrical connecting shaft 2 can have a variable length. This allows the length of the device according to the invention to be adapted to the length of the bore in the mounting plate. The cylindrical connecting shaft 2 is in turn connected at the other end to a clamping unit 3, preferably detachably (for example, via a screw connection).

[0074] The clamping unit 3 has a planar surface 3a inclined at an angle N on its upper side, where the angle N is a deviation from an imaginary horizontal line extending along the cylindrical surface of the cylindrical section of the clamping unit and parallel to the longitudinal axis L of the clamping unit. In the Fig. 1 In the illustrated embodiment, the clamping unit 3 has a circular cross-section at the end connected to the connecting shaft 2, while the clamping unit 3 has a circular segment cross-section at the free end.

[0075] In Fig. 1 A rotation lock 4 is also visible, comprising a guide rod 4a arranged parallel to the hydraulic cylinder and a guide plate 4b. The guide rod 4a is located at the front end of the cylinder housing 1a. In the installed state, the other end of the guide rod (as shown in the diagram) Fig. 6 (as can be seen) preferably arranged and thus fixed in a bulge 11b and a fixation point 11c.

[0076] The guide plate 4b has a front section with a circular opening in which the guide rod 4a is arranged. The guide plate 4b can be moved forwards and backwards along the guide rod 4a. Since the front section of the guide plate 4b is attached to the connecting shaft 2, the guide plate 4b is moved when the connecting shaft 2 is moved (due to the hydraulic movement of the cylinder piston 1b and the associated movement of the piston rod 1b, to which the connecting shaft 2 is attached).

[0077] In the Fig. 1 In the illustrated embodiment, the guide plate 4b has a further section which forms an angle of 90° with the front section. This further section extends into an area laterally to the cylinder housing 1a and is movably arranged there. This further section of the guide plate 4b can interact with two sensors 6a and 6a, which are arranged on the same side of the cylinder housing 1a. This is shown in Fig. 3 explained in more detail.

[0078] The clamping unit 3 continues to have, in the embodiment according to Fig. 1 two outlet openings 5b for a lubricant, of which in Fig. 1 For perspective reasons, only one opening is visible.

[0079] In Fig. 2 A sectional view of an embodiment of the mold clamping device according to the invention is shown. For illustrative purposes, the clamping unit 3 is shown such that the inclination angle N is visible. Furthermore, in Fig. 2 The cylinder piston is shown in 1b.

[0080] In Fig. 3 Figure 1 shows a schematic representation of an embodiment of the end-position monitoring of the mold clamping device according to the invention. As described above, two sensors 6a and 6b are located on one side of the cylinder housing 1a. The sensors 6a and 6b are arranged such that one sensor 6a is located at the front lateral end of the cylinder housing 1a and one sensor 6b is located at the rear lateral end of the cylinder housing 1a. These positions correspond to the fully extended and fully retracted positions of the cylinder piston 1b in the hydraulic cylinder 1. The guide plate 4b has an end section (here in the form of a tab) which can interact with the sensors 6a, 6b when it is in a position in front of the corresponding sensor 6a, 6b.When the hydraulic piston 1b is moved from a fully retracted position to a fully extended position, the piston rod 1c and the connecting shaft 2 attached to the hydraulic piston 1b move simultaneously. Since the guide plate 4b is connected to the connecting shaft 2 as described above, the guide plate 4b moves accordingly, and this movement can be detected by sensors 6a and 6b. Thus, by detecting the position of the end section of the guide plate 4b, sensors 6a and 6b determine the position of the connecting shaft 2 and the clamping unit 3 attached to it.

[0081] In Fig. 4 Figure 1 shows a schematic representation of an embodiment of the lubrication system 5 of the mold clamping device according to the invention. Lubricant is supplied through a lubricant line 5a. The lubricant line 5a is arranged within the connecting shaft 2 and the clamping unit 3 and terminates in the embodiment shown. Fig. 4 in an outlet opening 5b, which is located here on the upper side of the clamping unit 3. Preferably, the outlet openings 5b are located in the section in which the clamping unit 3 has an inclined planar surface 3a.

[0082] In Fig. 5 Figure 1 shows a schematic representation of an embodiment of a mounting plate A, A' according to the invention. Fig. 5 The image shows a fixed mounting plate. However, it could also be a movable mounting plate.

[0083] The mounting plate A, A' has a front surface 10a to which a die-casting mold half 12a, 12b (not shown here) is attached (clamped). The mounting plate A, A' also has a back surface 10b and side surfaces 10c. Openings 7 for guide rods are provided in the corners of the mounting plate A, A'.

[0084] In the front face 10a, openings 8 are provided for clamping bolts. The clamping bolts arranged on a die-casting mold half 12a, 12b (not shown here) can be inserted into these openings 8. In the embodiment according to Fig. 5 Four such openings 8 are discernible, arranged symmetrically in two rows to ensure optimal attachment of the die-casting mold half 12a, 12b. Further openings 8 are also conceivable.

[0085] Openings 9 for the mold clamping device E according to the invention are provided in the side surfaces 10c. The number of openings 9 provided corresponds to the number of openings 8 provided. Each opening 9 is connected by a Fig. 6 The bore 11a shown is connected to one of the openings 8.

[0086] In Fig. 6 Figure 1 shows a schematic representation of an embodiment of a bore 11a provided in the mounting plate A, A' according to the invention.

[0087] The bore 11a connects an opening 8, which is provided in the front face 10a of the mounting plate A, A' and serves for the insertion of a clamping bolt of a mold half 12a, 12b, with an opening 9. The opening 9 is provided in a side surface 10a of the mounting plate A, A' as described above and serves for the insertion of the mold clamping device E according to the invention. The bore 11a is designed such that the piston rod 1c, the connecting shaft 2 and the clamping unit 3 of the mold clamping device E according to the invention can move back and forth within it.

[0088] Borehole 11a has a circular cross-section.

[0089] In addition to the actual bore 11a, a protrusion 11b with a fixing point 11c is provided, which serves to receive the guide rod 4a and the guide plate 4b of the mold clamping device E according to the invention. At the end of the protrusion 11b, a receiving area is provided in which the free end of the guide rod 4a can be fixed.

[0090] In Fig. 7 A side view of a die-casting machine D according to an embodiment of the present invention is shown.

[0091] The die-casting machine D includes a fixed mounting plate A. , which here is a fixed mounting plate A of the embodiment according to Fig. 5 The die-casting machine D further comprises a movable mounting plate A', which here also includes a mounting plate A according to the embodiment shown. Fig. 5 The clamping plates A and A' are arranged on a machine frame 14. While the fixed clamping plate A is rigidly connected to the machine frame 14, the movable clamping plate A' can be moved from an open position to a closed position and vice versa on guide columns 13 on the machine frame 14 by means of a drive (not shown here) in a known manner. Fig. 7 The movable mounting plate A' is in the closed position. The guide columns 13 are arranged in receiving openings 7 of the fixed mounting plate A and in receiving openings 7 of the movable mounting plate A' (see figure). Fig. 5 ).

[0092] Between the mounting plates A and A' is a mold, which here consists of two mold halves 12a and 12b. The mounting plates A and A' have openings 8 for the insertion of clamping bolts 15, which are provided on the mold halves 12a and 12b.

[0093] In Fig. 8a Figure 1 shows a sectional view of an embodiment of the mold clamping device E according to the invention in an open (unclamped) position.

[0094] In the open (unloaded) position, the cylinder piston 1b in the hydraulic cylinder 1 is in its fully retracted position (in the drawing, at the far left of the hydraulic piston 1). Consequently, the components connected to the cylinder piston 1b (piston rod 1c, connecting shaft 2, clamping unit 3, guide plate 4b) are in a retracted position. The mold clamping device E is located in the bore 11a.

[0095] In Fig. 8a A clamping bolt 15 of a die-casting mold half 12a, 12b is shown schematically, which is located in the opening 8 of the mounting plate A, A'. The clamping bolt comprises an opening 15a which has a cross-section that, in the closed position of the clamping unit 3, enables a wedge-shaped clamping action with the inclined planar surface 3a of the clamping unit 3. As shown in Fig. 8a Preferably shown, the opening 15a of the clamping bolt 15 comprises a similarly inclined planar surface. The inclination and dimension of the planar surface in the opening 15a of the clamping bolt 15 correspond to the inclination and dimension of the planar surface 3a of the clamping unit 3. When the wedge-shaped section of the clamping unit is inserted into the opening 15a, which has a cross-section that allows wedge-shaped clamping with the inclined planar surface 3a of the clamping unit 3 (i.e., has a complementary dimension), the wedge shape assists (or even forces) a movement of the form 12a, 12b towards the mounting plate A, A'. In the closed state (i.e., when the clamping unit 3 is inserted maximally into the opening 15a of the clamping bolt 15), a clamping force is generated which ultimately secures the form 12a, 12b to the mounting plate A, A' in a positive and non-positive manner.

[0096] In the open position, the clamping unit 3 is located outside the opening 15a of the clamping bolt 15. The clamping bolt 15 can be removed from the opening 8 without hindrance.

[0097] The end of the guide plate 4b is located at the sensor 6b, which thus detects that the mold clamping device E is in the open position.

[0098] In Fig. 8b Figure 1 shows a sectional view of an embodiment of the mold clamping device E according to the invention in a closed (clamped) position.

[0099] In the closed (tensioned) position, the cylinder piston 1b in the hydraulic cylinder 1 is in its maximum extended position (at the far right of the hydraulic cylinder 1 in the drawing). Consequently, the components connected to the cylinder piston 1b (piston rod 1c, connecting shaft 2, clamping unit 3, guide plate 4b) are in an extended position. The mold clamping device E is located in the bore 11a.

[0100] In the closed position, the clamping unit 3 is located within the opening 15a of the clamping bolt 15. The clamping bolt 15 cannot be removed from the opening 8. This is facilitated by the fact that the opening 15a of the clamping bolt 15 has a cross-section which, in the closed position of the clamping unit 3, enables a wedge-shaped clamping action with the inclined planar surface 3a of the clamping unit 3. Fig. 8b The opening 15a of the clamping bolt 15 also comprises an inclined planar surface. The inclination and dimension of the planar surface in the opening 15a of the clamping bolt 15 correspond to the inclination and dimension of the planar surface 3a of the clamping unit 3.

[0101] The end of the guide plate 4b is located at the sensor 6a, which thus detects that the mold clamping device E is in the closed position.

[0102] In Fig. 9a Figure 1 shows a schematic representation of an embodiment of a clamping bolt 15 in an open position of the mold clamping device E according to the invention. In this embodiment, the opening 15a of the clamping bolt 15 is a through bore with a stadium-shaped (elongated) cross-section. This is preferred for the Fig. 9a und 9b In the case shown, the clamping unit 3 has a sloping planar surface 3a as described above on the top and bottom of the clamping unit 3.

[0103] In Fig. 9b is a schematic representation of the embodiment of a clamping bolt 15 according to Fig. 9a The clamping device E according to the invention is shown in a closed position. The clamping unit 3 has an inclined planar surface 3a as described above on its upper and lower sides. Due to the stadium-shaped cross-section of the opening 15a of the clamping bolt 15, an optimal wedge-shaped clamping action with the clamping unit 3 occurs at the right lateral section of the opening 15a.

Claims

1. Device (E) for clamping a die-casting mold, comprising: - a hydraulic cylinder (1) with a housing (1a) and a piston (1b) movably arranged in the cylinder (1), on which a cylindrical piston rod (1c) is arranged, - a cylindrical connecting shaft (2), the first end of which is connected to the free end of the piston rod (1c), - a cylindrical clamping unit (3), which is connected to a second end of the connecting shaft (2) and has a cross-section that varies along its longitudinal axis (L), such that the clamping unit (3) has a planar surface (3a) in one section, - an anti-rotation device (4), and - a lubrication system (5). characterized by the fact thatthe planar surface (3a) of the clamping unit (3) has an inclination (N) towards the longitudinal axis (L) which is in the range of 1° to 12°, and the anti-rotation device (4) comprises a fixedly arranged guide rod (4a) which extends parallel to the connecting shaft (2) and clamping unit (3).

2. Device according to claim 1, characterized by the fact that the inclination (N) of the planar surface (3a) of the clamping unit (3) is in the range of 5° to 10°.

3. Device according to claim 1 or 2, characterized by the fact that the guide rod (4a) is fixed to the side surface of the housing (1a), from which the piston rod (1c) extends.

4. Device according to one of claims 1 to 3, characterized by the fact that The anti-rotation device (4) further comprises a guide plate (4b) which is attached to a rear end of the connecting shaft (2) facing away from the clamping unit (3) and can be moved along the guide rod (4a) by means of a recess.

5. Device according to claim 4, characterized by the fact that the guide plate (4b) is movably arranged next to the hydraulic cylinder (1).

6. Device according to claim 5, characterized by the fact that Sensors (6a, 6b) are arranged on the housing (1a) of the hydraulic cylinder (1), preferably one sensor (6a, 6b) each at the front side end and rear side end of the housing, and the guide plate (4b) can interact with a sensor (6a, 6b) when it is in a position in front of the sensor (6a, 6b).

7. Device according to any one of claims 1 to 6, characterized by the fact that the lubrication system (5) comprises a line (5a) which runs partly inside the connecting shaft (2) and the clamping unit (3) and has at least one outlet opening (5b) arranged in the clamping unit (3).

8. Mounting plate (A, A') for a die-casting machine (D), comprising a front (10a), a back (10b) and side surfaces (10c), wherein the front (10a) has at least one opening (8) for receiving a clamping bolt of a die-casting mold half, wherein the opening (8) for receiving the clamping bolt is connected to a bore (11a) which extends from an opening (9) in a side surface (10c) of the mounting plate (A, A') to the opening (8) for receiving the clamping bolt, characterized by the fact that the bore (11a) has a circular cross-section.

9. Mounting plate according to claim 8, characterized by the fact that it has 2-10, preferably 4-8, particularly preferably 8 symmetrically arranged openings (8) for receiving a clamping bolt of a die-casting mold half as well as the associated openings (9) and bores (11a).

10. Mounting plate according to claim 8 or 9, characterized by the fact thatin at least one, preferably in each bore (11a) a device (E) according to one of claims 1 to 8 is arranged.

11. Die casting machine (D) comprising at least one mounting plate (A, A') according to one of claims 8 to 10.

12. A method for clamping a die-casting mold half (12a, 12b) onto a mounting plate (A, A') for a die-casting machine (D) according to any one of claims 8 to 10, comprising the steps of: a) inserting a clamping bolt (15), which is arranged on a front side of the die-casting mold half (12a, 12b), into the opening (8) of the mounting plate (A, A') to receive the clamping bolt; b) moving the clamping unit (3) of the device (E) located in the bore (11a) of the mounting plate (A, A') according to any one of claims 1 to 8 in the presence of a lubricant by hydraulic actuation of the hydraulic cylinder (1) from an open position to a closed position, wherein the clamping unit (3) in the closed position is inserted into an opening (15a) of the clamping bolt (15), wherein the opening (15a) of the clamping bolt (15) has a cross-sectionwhich, in the closed position of the clamping unit (3), enables a wedge-shaped clamping with the inclined planar surface (3a) of the clamping unit (3).

13. Method according to claim 12, characterized by the fact that the opening (15a) of the clamping bolt (15) is a continuous bore with a stadium-shaped cross-section.

14. Method according to claim 12 or 13, characterized by the fact that In step b) an additional guide plate (4b) is moved along a guide rod (4a) parallel and synchronously to the connecting shaft (2) and to the clamping unit (3) to prevent rotation of the clamping unit (3).

15. Method according to claim 14, characterized by the fact thatthe movement of the guide plate (4b) is detected by sensors (6a, 6b) arranged on the housing (1a) of the hydraulic cylinder (1), preferably one sensor (6a, 6b) each arranged at the front lateral end and one at the rear lateral end of the housing (1a), wherein the guide plate (4b) interacts with a sensor (6a, 6b) when it is in a position in front of the sensor (6a, 6b).

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