Die-casting piston

Abstract

A die-casting piston having a receiving unit attachable to a piston rod, which includes a cooling device and a connecting device for the piston rod. A hollow cylindrical carrier body of a cup-shaped design has a melt-side end face, on whose lateral surface at least one hollow cylindrical sliding body is mountable. An end ring is disposed between the end face of the carrier body and an end face of the sliding body, which is used as a front-end first holding element for the at least one hollow cylindrical sliding body. The carrier body is axially mountable on the receiving unit, extending over the cooling device, and may be locked to the receiving unit and released again with the aid of a connecting device, the connecting device being disposed axially downstream from the sliding body on the side facing away from the end face of the carrier body, and the connecting device being a bayonet joint.

Claims

1. A die-casting piston comprising: a receiving unit attachable to a piston rod, the receiving unit having a cooling device and a first connecting device for the piston rod; a hollow cylindrical carrier body having a cup-shaped design, the hollow cylindrical carrier body including a melt-side end face and a lateral surface, at least one hollow cylindrical sliding body being mounted on the lateral surface; and an end ring being arranged between the melt-side end face of the carrier body and an end face of the at least one hollow cylindrical sliding body, the end ring being a front-end first holding element for the at least one hollow cylindrical sliding body, wherein the carrier body is axially mountable on the receiving unit extending over the cooling device and is adapted to be locked to the receiving unit and released again via a second connecting device, wherein the second connecting device is arranged axially downstream from the at least one hollow cylindrical sliding body on a side facing away from the melt-side end face of the carrier body, wherein the second connecting device is a bayonet joint, wherein the at least one hollow cylindrical sliding body is fixable on a side facing away from the melt-side end face of the carrier body by a mounting ring, and wherein the mounting ring is designed to be rotatably fixed with respect to the carrier body.

2. The die-casting piston according to claim 1, wherein the carrier body is rotatably fixedly lockable with respect to the receiving unit with the aid of at least one fixing element, and wherein the at least one fixing element is accessible on an outer circumference of the piston for locking purposes.

3. The die-casting piston according to claim 1, wherein at a position of the mounting ring, an outer contour of the carrier body is designed as a polygon, and wherein an inner contour of the mounting ring is designed as a polygon that corresponds with the outer contour of the carrier body.

4. The die-casting piston according to claim 1, wherein the end ring is supported against a front-end stop formed on the carrier body to prevent axial displacement.

5. The die-casting piston according to claim 4, wherein the front-end stop is a circumferentially running projection from the lateral surface of the carrier body.

6. The die-casting piston according to claim 1, wherein at least the end ring and the at least one hollow cylindrical sliding body, that is directly adjacent thereto, have complementary shoulders that mesh in an overlapping manner, the complementary shoulders being front end joints.

7. The die-casting piston according to claim 1, wherein the end ring is made from a harder material than the at least one hollow cylindrical sliding body.

8. A die-casting piston comprising: a receiving unit attachable to a piston rod, the receiving unit having a cooling device and a first connecting device for the piston rod; a hollow cylindrical carrier body having a cup-shaped design, the hollow cylindrical carrier body including a melt-side end face and a lateral surface, at least one hollow cylindrical sliding body being mounted on the lateral surface; and an end ring being arranged between the melt-side end face of the carrier body and an end face of the at least one hollow cylindrical sliding body, the end ring being a front-end first holding element for the at least one hollow cylindrical sliding body, wherein the carrier body is axially mountable on the receiving unit extending over the cooling device and is adapted to be locked to the receiving unit and released again via a second connecting device, wherein the second connecting device is arranged axially downstream from the at least one hollow cylindrical sliding body on a side facing away from the melt-side end face of the carrier body, wherein the second connecting device is a bayonet joint, wherein the at least one hollow cylindrical sliding body is fixable on a side facing away from the melt-side end face of the carrier body by a mounting ring, and wherein, at a position of the mounting ring, an outer contour of the receiving unit has a maximum radial extension as a polygon, which is smaller than an inner diameter of the at least one hollow cylindrical sliding body.

9. A die-casting piston comprising: a receiving unit attachable to a piston rod, the receiving unit having a cooling device and a first connecting device for the piston rod; a hollow cylindrical carrier body having a cup-shaped design, the hollow cylindrical carrier body including a melt-side end face and a lateral surface, at least one hollow cylindrical sliding body being mounted on the lateral surface; and an end ring being arranged between the melt-side end face of the carrier body and an end face of the at least one hollow cylindrical sliding body, the end ring being a front-end first holding element for the at least one hollow cylindrical sliding body, wherein the carrier body is axially mountable on the receiving unit extending over the cooling device and is adapted to be locked to the receiving unit and released again via a second connecting device, wherein the second connecting device is arranged axially downstream from the at least one hollow cylindrical sliding body on a side facing away from the melt-side end face of the carrier body, wherein the second connecting device is a bayonet joint, wherein the at least one hollow cylindrical sliding body is fixable on a side facing away from the melt-side end face of the carrier body by a mounting ring, and wherein an outer contour of the mounting ring is designed as a polygon.

10. The die-casting piston according to claim 9, wherein the at least one fixing element is arranged on the outer contour of the mounting ring on a surface of the polygon.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

(2) FIG. 1 shows a schematic representation of an axial longitudinal section of a die-casting piston according to an embodiment of the invention;

(3) FIG. 2 shows a schematic representation of an axial longitudinal section of a modularly constructed carrier body;

(4) FIG. 3 shows a schematic view of a receiving unit;

(5) FIG. 4 shows a schematic representation of a cross section of a die-casting piston according to an embodiment of the invention in the plane of the bayonet joint; and

(6) FIG. 5 shows an exploded drawing of a modularly constructed carrier body.

DETAILED DESCRIPTION

(7) FIG. 1 shows a schematic representation of an axial longitudinal section along piston axis A of a die-casting piston 1 according to the invention. Die-casting piston 1 having direct cooling includes a carrier body 3, which also forms the melt-side end face 31 of die-casting piston 1. A slide bush is disposed on carrier body 3 as a hollow cylindrical sliding body 4. A preferably closed end ring 5 as a first holding element, which is preferably made from a harder material than sliding body 4, is disposed on lateral surface 32 of carrier body 3 between end face 31 of carrier body 3 and front-end face 41 of sliding body 4. Sliding body 4 is protected in this manner against direct contact with the hot casting material.

(8) In FIG. 1, carrier body 3 is mounted on receiving unit 2, extending over cooling device 21, and locked to receiving unit 2 with the aid of a bayonet joint 6 as the connecting device. Carrier body 3 and receiving unit 2 are consequently connected to each other as connecting partners by an insertion-and-rotation motion. In this specific embodiment, receiving unit 2 has suitable metallic tabs for this purpose. Receiving unit 2 is designed in such a way that the metallic tabs are able to engage with corresponding recesses of carrier body 3. Connecting device 22 for the piston rod is located on the back of receiving unit 2 facing away from carrier body 3.

(9) The connection of carrier body 3 is rotatably fixedly locked with respect to receiving unit 2 by a screw-like or pin-like fixing element 7, whereby the unintentional opening of the bayonet joint is prevented. Fixing element 7 is preferably disposed on the outer circumference of the piston and is thus located at an easily accessible point on die-casting piston 1. Radially engaging locking mechanisms, which are accessible from the cylindrical surface of die-casting piston 1, are particularly suitable.

(10) Mounting ring 8 is used as a second holding element having a back-side stop, which is planarly abutted by the reversing front end of hollow cylindrical sliding body 4. The radial extension of mounting ring 8 is preferably slightly smaller than the radial extension of sliding body 4.

(11) A front-end stop 33 is used to retain preferably closed end ring 5, whereby end ring 5 is supported against axial displacement toward the front. Front-end stop 33 is a circumferentially running projection from lateral surface 32 of carrier body 3. The projection is created in such a way that the axial forces occurring during operation may be absorbed. End ring 5 and directly adjacent, hollow cylindrical sliding body 4 have complementary shoulders at particular front-end joints 41, whereby they mesh in an overlapping manner.

(12) FIG. 2 shows a schematic representation of an axial longitudinal section of a modularly constructed carrier body 3. The wearing parts that are stressed the most by temperature or by friction are disposed on hollow cylindrical carrier body 3, which is easily removable as a module from the receiving unit. Hollow cylindrical sliding body 4 is pushed onto lateral surface 32 of carrier body 3 and secured by an end ring 5 closing on the front. End ring 5 itself is fixed by a front-end stop 33 formed in carrier body 3, which prevents an axial displacement over end face 31 of carrier body 3. These parts may be removed again and replaced in the opposite order. With the aid of bayonet joint part 61, and possibly with the aid of tools set on mounting ring 8, the entire module may then be connected to the receiving unit using bayonet joint part 62 located thereon. Fixing element 7 prevents the unintentional counter-rotation movement for opening the bayonet joint.

(13) FIG. 3 shows a schematic view of a receiving unit 2. The part facing the front end of the piston forms cooling device 21 in connection with the inner wall of the carrier body. Connecting device 22 for the piston rod is located on the back of receiving unit 2 facing away from carrier body 3. Bayonet joint part 62 of receiving unit 2 is located between cooling device 21 and connecting device 22. In this embodiment, receiving unit 2 has metallic tabs for this purpose, which may engage with corresponding recesses of the carrier body for connecting purposes. Recess 24 is a bore, with which a fixing element engages in the mounted state.

(14) FIG. 4 shows a schematic representation of a cross section of a die-casting piston 1 according to the invention in the plane of bayonet joint 6. Receiving unit 2 is situated internally in this sectional plane. Hollow cylindrical carrier body 3 encompasses receiving unit 2 with the aid of mounting ring 8, forming bayonet joint 6. Within mounting ring 8, the outer contour of carrier body 3 is designed as a polygon 35, and the inner contour of mounting ring 8 is also designed as a polygon 81, which forms a precise fit with the outer contour of carrier body 3. This necessitates the desired anti-rotation protection of both parts with respect to each other. The outer contour of mounting ring 8 is also designed as a polygon 82 as a mounting aid and for setting suitable mounting tools. Mounting ring 8 and carrier body 3 are locked to receiving unit 2 and secured with the aid of the three fixing elements 7 illustrated in FIG. 4.

(15) FIG. 5 shows an exploded drawing of a modularly constructed carrier body 3, including the additional components. In the order illustrated, end ring 5, hollow cylindrical sliding body 4 and mounting ring 8 are pushed onto carrier body 3 before this module unit is connected to the receiving unit, forming the bayonet joint.

(16) The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.