mold clamping unit

Abstract

A 2-plate mold clamping unit is described with a first fixed mold clamping plate (2) and a second movable mold clamping plate (3), which can be moved towards and away from the fixed mold clamping plate (2), with pressure pads (5) for generating a clamping force, and with columns (4) for absorbing the clamping force.According to the invention, the movable mold clamping plate (3) has U-shaped recesses (11) on its vertical sides for receiving the columns (4), the columns (4) are arranged displaceably in the fixed mold clamping plate (2), the columns (4) can be moved independently of the movable mold clamping plate (3) in the longitudinal direction of the mold closing unit relative to the fixed mold clamping plate (2), the columns (4) have a column head (6) at their end associated with the movable mold clamping plate (3), the diameter of which is greater than the diameter of the associated column (4), the pressure pads (5) are provided on the fixed mold clamping plate (2), and the movable mold clamping plate (3) is rotatable about a vertical axis.

Description

[0001] The invention relates to a 2-plate mold clamping unit according to the preamble of claim 1.

[0002] Two-platen mold clamping units in various designs are known from the prior art. Typically, a fixed and a movable mold clamping platen are arranged on a common machine bed, with the movable mold clamping platen being movable relative to the fixed platen by means of suitable drive means. Document DE 20 2022 102 721 U1 shows a two-platen machine with a rotary table and U-shaped recesses in the indexable platen. Documents DE 10 2013 006 713 A1 and US Pat. No. 5,830,404 A show rotating mechanisms at the end of the columns. These rotating mechanisms have a horizontal axis of rotation and can be used to bring different mold halves together with a mold half on the fixed platen.

[0003] Such two-platen mold clamping units require a comparatively large amount of space, especially when using deep-cavity injection molds. Furthermore, setting up large injection molds is generally only possible using a tie-bar puller.

[0004] Based on this, the invention is based on the object of providing a 2-platen mold clamping unit characterized by a comparatively small footprint. A further object of the present invention can be seen in providing a 2-platen mold clamping unit that does not require a tie-bar puller, even when using relatively large injection molds.

[0005] This object is achieved by a mold closing unit having the features of claim 1. Advantageous embodiments and further developments can be found in the dependent claims.

[0006] According to a key concept of the present invention, the movable mold clamping plate is rotatable about a vertical axis. According to the invention, the movable mold clamping plate has U-shaped recesses on its vertical sides for receiving the columns. The columns are slidably arranged in the fixed mold clamping plate and can be moved independently of the movable mold clamping plate in the longitudinal direction of the machine relative to the fixed mold clamping plate. At their end facing the movable mold clamping plate, the columns have a column head whose diameter is larger than the diameter of the associated column. The pressure pads for generating the clamping force are provided on the fixed mold clamping plate.

[0007] Due to the rotatability of the movable mold clamping plate, the removal of injection-molded parts can take place in a lateral position (the so-called 90° position - see below). Therefore, the opening stroke of the injection mold can be shorter compared to the conventional removal of parts in the space between the two mold halves that are simply moved up. This allows the clamping bed or the section of the machine bed that accommodates the mold clamping unit to be designed shorter. The injection molding machine as a whole has a more compact design, requiring less floor space.

[0008] Since the columns are designed to be movable, a separate column pulling device is not required.

[0009] According to a first embodiment, the movable mold clamping plate can be arranged on a rotary table, and the rotary table can be moved in the longitudinal direction of the mold clamping unit. A rotary drive can be provided, with which the rotary table and the movable mold clamping plate located thereon can be rotated about a vertical axis. Preferably, the rotary table can be arranged on a sliding table, which can be moved in the longitudinal direction of the mold clamping unit.

[0010] One or more drives can be provided to move one or more of the columns in the longitudinal direction of the mold clamping unit. A separate drive can be provided for each column. However, it is also possible to couple two columns together in a suitable manner so that both columns are moved simultaneously using a single drive.

[0011] In a first embodiment of the drive, a hydraulically actuated drive cylinder can be provided for each column to move the columns. However, two columns can also be connected to each other via a support in a force-locking and / or positive-locking manner, with a separate drive cylinder provided for each of the two supports.

[0012] However, a motor can also be provided to move a column, with the associated column having teeth or grooves. The motor's drive shaft should then have a suitable drive element that meshes with the teeth or grooves.

[0013] The tie bars are preferably designed to ensure optimal force transmission to the movable mold clamping platen, particularly during the build-up of clamping force. For this purpose, the tie bars have a tie bar at their end facing the movable mold clamping platen, the diameter of which is suitably larger than the diameter of the associated tie bar. The exact axial extension of a tie bar and its diameter can be selected according to the structural design of the mold clamping unit.

[0014] Sliding layers or sliding plates can be provided in the U-shaped recesses in the movable mold clamping plate in order to largely avoid abrasion between the movable mold clamping plate and the columns.

[0015] The positioning of the movable mold clamping plate on the turntable may depend on the injection molds to be used. Therefore, the movable mold clamping plate can be mounted centrally or eccentrically on the turntable to achieve optimal weight distribution with the subsequent injection mold.

[0016] For tool setup and production flow, the movable mold clamping plate can be rotated around its vertical axis using the turntable and moved into any desired position. Typically, the following positions can be approached and adopted as preferred positions: 0° position: In this position, the mold clamping surface of the movable mold clamping platen faces the stationary mold clamping platen. With the injection mold installed, an injection molding process can be performed under clamping force. 90° - Position: In this position, the mold clamping surface of the movable mold clamping platen is aligned parallel to the longitudinal axis of the mold clamping unit. Depending on the application, the mold clamping surface can be aligned toward the operating side of the injection molding machine or the opposite side. In this position, the columns are free and can be moved toward the injection unit. 180° position: In this position, the tool clamping surface of the movable mold clamping plate is facing away from the fixed mold clamping plate.

[0017] Depending on requirements, the movable mold clamping plate can be set up with an injection mold part in a 90° position or in a 180° position.

[0018] Likewise, the removal of an injection-molded part can be performed at a 90° or 180° position, as required. Removal can be performed using a robot and / or an ejector. This can be done in one of the aforementioned positions or any other position. Removal can also occur during the rotation of the movable mold platen.

[0019] The invention will be explained below using an embodiment and with reference to the Fig. 1 to 3 are described in more detail.

[0020] They show: Fig. 1 Side view of a mold closing unit according to the invention; Fig. 2 Top view of a mold closing unit according to the invention; Fig. 3 View of the movable platen from the direction of arrow P in the Fig. 1.

[0021] A fixed mold clamping plate 2 is mounted on a machine bed 1 of an injection molding machine. For the sake of clarity, an injection unit of a known design is not shown, which is also mounted on the machine bed 1, namely in the Fig. 1 to the right of the stationary mold clamping platen 2. On or in the machine bed 1 (or optionally on the floor) there is mounted a sliding table 7 which can be moved in the longitudinal direction of the mold clamping unit by means of a drive device (not shown here but known per se). A rotary table 8 is mounted on the sliding table 7. The movable mold clamping platen 2 is fastened to the rotary table 8 in a suitable manner. The mounting between the rotary table 8 and the sliding table 7 is such that the weight of the rotary table 8 and the movable mold clamping platen 2 fastened thereon, together with the parts of an injection molding tool fastened thereto, hereinafter also referred to as mold halves, is carried by the sliding table 7 and the rotary table 8, together with the movable mold clamping platen 3 and the mold halves mounted thereon, can be rotated about a vertical axis.In the corner areas of the mold clamping unit, columns 4 are provided to absorb the clamping force. Four pressure pads 5 are provided on the stationary mold clamping plate 2 to generate the clamping force. Furthermore, known locking elements are provided. These can be an integral part of the pressure pad. In this case, they can also be referred to as a pressure locking pad.

[0022] U-shaped recesses 11 are provided on the vertical sides of the movable mold clamping plate 2. These recesses 11 can be introduced into the movable mold clamping plate by material removal, such as milling. These recesses 11 are designed so that the columns 4 can be inserted into them. The column heads 6 have a diameter which is suitably larger than the diameter of the associated column. The column heads 6 are particularly designed so that they exert an optimal force transmission to the movable mold clamping plate 3. In the present embodiment, two travel cylinders 9 are mounted at the level of the symmetry axis of the mold clamping unit on both sides of the stationary mold clamping plate 2 for moving the columns. In the side view of the Fig.1, only the front travel cylinder is visible, whereas the rear travel cylinder is concealed. Each of these travel cylinders 9 is drive-connected to a support 10, with the piston rod 9a preferably being attached to the support 10. Each of the supports 10 connects an upper and a lower column. By actuating the travel cylinders 9, the associated supports 10 and thus the columns coupled to them can be moved in the longitudinal direction of the mold clamping unit. In principle, however, a separate travel cylinder could also be provided for each column. In this case, the supports 10 would be dispensable.

[0023] Instead of drive cylinders, a motor can also be provided, with the associated column having teeth or grooves. The motor's drive shaft should then have a suitable drive element that meshes with the teeth or grooves.

[0024] The following describes the setup of an injection mold. According to a first variant, the movable mold clamping plate 3 is brought into a 90° position. This frees up the columns 4 and allows them to be moved in the direction of the injection unit (not shown here). This exposes the mold clamping surface of the movable mold clamping plate. Depending on the customer's needs and preferences, setup can alternatively be carried out in the 180° position, with the injection mold being set up in the free rear area of ​​the mold clamping unit. As soon as the entire injection mold is attached to the movable mold clamping plate 3, it can be rotated and brought into the 0° position. The clamping unit can then be closed and the injection mold can also be attached to the stationary mold clamping plate 2. The injection mold can then be unlocked / unlocked orThe mold halves can be separated from each other so that each mold clamping plate carries one mold half of the injection mold.

[0025] The production process is described below. The two mold halves of the injection mold are moved together via the movement of the sliding table 7, and the injection mold is closed. Parallel to this movement, the columns 4 are moved to the rear of the movable mold clamping plate 3. As soon as the movable mold clamping plate 3 and the columns 4 form a mold connection via the respective column head 6, the columns 4 are locked and clamping force is built up. The material for the molded parts is then injected into the cavities of the injection mold. After a sufficient cooling time, the clamping force is released. The columns 4 and the movable mold clamping plate 3 move apart, with the columns 4 being brought to a maximum rear position, which allows the movable mold clamping plate to rotate.The column heads 6 are thus moved into a position in which they are at a maximum distance from the stationary mold clamping plate 2. Subsequently, the movable mold clamping plate 3 is rotated to a 90° or 180° position to enable side or rear removal of the molded part(s). After the rotation is complete, or during the rotation, the molded part(s) are pushed out of the injection mold by an ejector. After the molded part removal is complete, the aforementioned production process is repeated. List of reference symbols 1 machine bed 2 Fixed mold clamping plate 3 Movable mold clamping plate 4 pillars 5 pressure locking cushions 6 column heads 7 Sliding table 8 Turntable 9 drive cylinder piston rod 9a 10 beams 11 U-shaped recesses

Claims

[1] Mould clamping unit with two mould clamping plates, namely a first fixed mould clamping plate (2) and a second movable mould clamping plate (3), which can be moved towards and away from the fixed mould clamping plate (2), with pressure cushions (5) for generating a clamping force, and with columns (4) for absorbing the clamping force, characterized bythat the movable mold clamping plate (3) has U-shaped recesses (11) on its vertical sides for receiving the columns (4), that the columns (4) are arranged displaceably in the fixed mold clamping plate (2), that the columns (4) can be moved independently of the movable mold clamping plate (3) in the longitudinal direction of the mold closing unit relative to the fixed mold clamping plate (2), that the columns (4) have a column head (6) at their end associated with the movable mold clamping plate (3), the diameter of which is greater than the diameter of the associated column (4), that the pressure pads (5) are provided on the fixed mold clamping plate (2), and that the movable mold clamping plate (3) is rotatable about a vertical axis. [2] Mold closing unit according to claim 1, characterized bythat the movable mold clamping plate (3) is arranged on a rotary table (8), that the rotary table (8) is movable in the longitudinal direction of the mold closing unit, and that a rotary drive is provided with which the rotary table (8) and the movable mold clamping plate (3) located thereon can be rotated about a vertical axis. [3] Mold closing unit according to claim 2, characterized by that the rotary table (8) is arranged on a sliding table (7) which can be moved in the longitudinal direction of the mold closing unit. [4] Mold closing unit according to one of the preceding claims, characterized by that one or more drives are provided with which one or more of the columns (4) can be moved in the longitudinal direction of the mold closing unit. [5] Mold closing unit according to claim 4, characterized byin that hydraulically actuated travel cylinders (9) are provided for moving the columns (4), wherein a separate travel cylinder (9) is provided for each of the columns (4), or wherein two columns (4) are non-positively and / or positively connected to one another via a support (10) and a travel cylinder (9) is provided for each of the two supports (10). [6] Mold closing unit according to claim 4, characterized by that the columns (4) have a toothing or grooves, and that a motor is provided whose drive shaft has a drive element meshing with the toothing or grooves. [7] Mold closing unit according to one of the preceding claims, characterized by that a sliding layer or sliding plates are provided in the U-shaped recesses (11).

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