TOOLING FOR RELEASING A CLUSTER OF PARTS FROM A LOST-WAX CASTING

Abstract

The invention relates to a tool (1) for removing a cluster (2) of lost-wax casting parts containing shell residue, the tool comprising: - a frame (10) extending along a first axis (Z), - support means (13) connected to the frame (10) and intended to support the cluster (2) of parts, the support means (13) being rotationally mobile relative to the frame (10), around a second axis (Y) perpendicular to the first axis (Z), and - a drive device (23, 24) configured so as to be remotely actuated and to rotate the support means (13) along the second axis (Y) under the action of a pressure greater than or equal to a determined pressure value exerted by a spray of a fluid jet (F) intended to remove the shell residue by impact.

Description

TOOLING FOR RELEASING A CLUSTER OF WAX FOUNDRY PARTS LOST 41. Scope of the invention The present invention relates to the field of lost-wax casting for the production of lost-wax cast metal parts. In particular, it relates to a tool for removing the shell, especially residual shell, from a cluster of lost-wax cast parts. 2. State of the art The lost-wax casting technique is particularly well-known for manufacturing complex-shaped parts, such as metal components for turbomachinery. The technique involves using a wax model or a similar material to create a mold called a shell. Once the wax is removed by various methods, cavities are formed that allow molten metal to be poured and filled. After the metal has cooled and solidified, the shell is removed to reveal the metal part in the shape of the model. In a particular technique, several wax models are arranged in a cluster to produce multiple metal parts simultaneously. In this case, the cluster comprises a ring supporting a pouring cup connected to a central shaft, which in turn supports the wax models. These models are also interconnected by channels coupled to the pouring cup and the central shaft. The shell is formed around the cluster of wax models, for example, by successive dippings in a ceramic slip, so as to completely encase the models and create a single piece. As with the production of a single metal part, the metal, having cooled and solidified after casting, is revealed by a step called "demolding" the shell, which involves its destruction. Generally, the shell is destroyed in two operations. The first operation consists of striking the shell with a tool such as a hammer or chisel to break the shell and remove the largest pieces of shell, and the second operation consists of sending a jet of pressurized water towards the cluster in order to eliminate the shell residues. However, because the metal parts have complex shapes and are arranged around the central shaft, it is necessary to manually rotate or rotate the cluster so that the water reaches all areas still containing shell residue. This rotation is performed several times by an operator. Up to six times, the process is repeated to treat all areas and remove all shell residue. Furthermore, the operator must enter a booth to access and handle the cluster. It should be noted that the cluster can weigh 10 kg or even up to 15 kg, depending on the metal parts obtained. These strenuous handling tasks can lead to health problems for operators, such as musculoskeletal injuries, and result in lost time. 3. Objective of the invention The applicant has therefore set himself the objective of providing a shakeout tooling that reduces, or even eliminates, manual intervention on a cluster of parts in order to remove all shell residue during a shakeout step. 4. Description of the invention This objective is achieved in accordance with the invention by means of a tooling for removing a cluster of lost-wax casting parts containing shell residue, the tooling comprising: a structure extending along a first axis, support means connected to the frame and designed to support the cluster of parts, the support means being mobile in rotation relative to the frame, around a second axis perpendicular to the first axis, and a training device configured to be operated remotely and to rotate the support means along the second axis under the action of a pressure greater than or equal to a specified pressure value by spraying a jet of fluid designed to remove residues by impact shell. Thus, this solution achieves the aforementioned objective. In particular, the tooling reduces, or even eliminates, the various manual interventions required by the operator to rotate and move the cluster during the destacking stage, resulting in time savings and a reduction in injuries to operators performing these manipulations. This configuration allows the use of the energy from the spray of a fluid used to destack the cluster's outer shell—in this case, water pressure—to rotate the cluster in at least one direction. We therefore utilize the available energy to rotate the cluster. Furthermore, allowing the support device to rotate remotely also prevents the cluster from falling and from being impacted. The tooling according to the invention may comprise one or more of the following features, taken individually or in combination with each other: The support means are mounted on the frame by means of fastening means removably fixed to the frame. The drive device comprises an operating member and a drive mechanism, the support means being driven in rotation by the operating member via the drive mechanism. The frame comprises at least one pylon extending along the first axis, the fastening means comprising at least one support mounted on the pylon, and the support means comprising at least one clamping element designed to hold the cluster by at least two protrusions and to rotate relative to the support around the second axis. The clamping element comprises a base and a tab pivoting relative to the base so as to clamp a protrusion between the base and the tab.The support means are fixed to at least one first drive shaft extending along the second axis, the first drive shaft being driven in rotation by the drive device. The reduction ratio of the reducing element is between 1 / 10 and 1 / 40. The drive mechanism comprises a reducing element with a toothed shaft meshing with a toothed pinion, the toothed pinion being coupled to the first drive shaft. The determined pressure value is between 150 and 450 bar. The operating element comprises a wheel with teeth projecting from its periphery, the teeth having receiving surfaces on which the determined pressure is applied.The frame comprises a table from which the pylon extends, a second drive shaft fixed to the table extending along the first axis, the second drive shaft being capable of rotating about the first axis so as to drive the rotation of the frame relative to a chassis. The invention also relates to a shakeout assembly comprising tooling having any of the aforementioned characteristics, a cluster of lost-wax castings containing shell residue and mounted for rotation relative to the frame on support means connected to the frame, and a fluid spraying element for spraying a fluid at a pressure greater than or equal to a predetermined pressure value, remotely actuating the drive device which rotates the support means along the first axis. second axis and to remove the shell residues by impact. The assembly according to the invention may comprise one or more of the following features taken individually or in combination: The assembly comprises a cabin equipped with a chassis, the frame table being connected to the chassis via the second drive shaft and mounted to rotate relative to the chassis so as to drive the rotation of the frame around the first axis. The cluster includes a ring having two radially arranged protrusions facing each other and intended to be held by clamping elements. Control elements are connected to the second drive shaft and are intended to remotely rotate the second drive shaft around the first axis. The invention also relates to a method for removing a cluster of lost-wax casting parts containing shell residue, the method comprising the following steps: an installation of the cluster on support means of a cluster unblocking tool having any of the aforementioned characteristics, the support means being mobile in rotation relative to the frame, and a spraying of a fluid jet towards the drive device at a pressure greater than or equal to a determined pressure value remotely actuating the drive device which drives the support means in rotation along the second axis, the fluid jet also being used to remove by impact the shell residues of the cluster. 5. Brief Description of the Figures The invention will be better understood, and other objects, details, features, and advantages thereof will become more apparent upon reading the following detailed explanatory description of an embodiment of the invention given by way of purely illustrative and non-limiting example, with reference to the schematic drawings attached in which: Figure 1 schematically represents, in perspective view, an example of tooling on which a cluster is mounted, trapped at least partially in a shell according to the invention; Figure 2 is a longitudinal cross-sectional view of an example of tooling according to the invention; Figure 3 is a top view of an example of tooling according to the invention; and Figure 4 is a perspective view of an assembly comprising a cabin in which is installed the tooling for removing carapace residues with water jets according to the invention. 6. Description of embodiments of the invention Figure 1 shows a tool 1 for removing a cluster 2 used to produce parts by a lost-wax or lost-model casting process. The cluster 2 is enclosed within a shell 3, which is designed to be destroyed during a shakeout step. The shell 3 is pre-made from a refractory material that forms a mold. In this example, the refractory material is a ceramic. In Figure 1, the cluster 2, with the shell 3, comprises a ring 4 and a central column 5 extending from the ring 4 along a longitudinal axis Z. The ring and the central column are coaxial. The ring 4 carries a pouring cup 7 through which molten metal is poured. This pouring cup 7 is coaxial with the central column 5. The shell 3 also includes several cavities (not shown) for forming the metal parts. These cavities are arranged around the central column 5 and on the periphery of the ring 4 to form the cluster 2. Conduits 8 also connect the pouring cup 7 to the cavities to convey the molten metal. The sprue 2 is pre-made from several identical part models, each intended to form a metal component, for example, a turbomachine. The models are formed from wax or an equivalent material and each has the shape of the desired metal component, such as turbomachine blades or distributor sectors, which include blades extending between two platforms. Of course, the part models can be used to form any metal component in the mechanical engineering industry. The wax sprue of part models is then processed to form the shell 3 described above, removing the wax that leaves cavities for the molten metal in the shell. The sprue 2 is, for example, successively dipped in a ceramic slip to create the shell 3. Once the metal is poured into the pouring hopper 7 into the cavities representing the metal parts and cooled, the shell 3 must be removed by a shakeout step to extract and finalize the resulting metal parts. These metal parts are casting blanks that will undergo several treatments and machining processes to produce the final metal part. During the shakeout step, the cluster 2 undergoes the first operation of breaking the shell 3 and removing the largest broken pieces. A second operation consists of removing any particles or residues of the shell 3 material still attached to the metal parts. The present invention enables the second operation of the shakeout step to be performed. For this purpose, the sprue 2 is installed in a booth 9 shown in Figure 4. This second operation is carried out by projecting a jet of fluid, such as water, towards the sprue 2 mounted on a frame 10 of the tooling 1. The impacts of the fluid jet spray detach the shell residue from the surface of the metal parts. The shakeout tooling is installed in a removable manner within the booth 9. The sprue 2 is also mounted on the frame 10 in a removable manner, allowing it to pivot or rotate about at least one axis of rotation relative to the frame 10. In Figure 1, the frame 10 comprises a table or base 11 from which at least one pylon 12 extends along the longitudinal axis Z. In this example, two pylons 12a, 12b extend from the table 11 along the longitudinal axis Z, which is vertical in this case relative to Figure 1. The first and second pylons 12a, 12b are spaced apart and parallel. The table 10 extends in a plane perpendicular to the longitudinal axis Z. The tooling 1 comprises support means 13 connected to the frame 10 and designed to support the cluster 2. The support means 13 are mounted to rotate relative to the frame 10 by means of fastening means 14. In Figure 3, the fastening means 14 include a support 15 mounted on each of the first and second pylons 12a, 120. Each support 15 comprises a first part 15a and a second part 15b movable relative to the first part 15a along an axis of rotation A parallel to the longitudinal axis Z. Each first part 15a and second part 15b has a cross-section substantially C-shaped or U-shaped, with two arms and a base. Each first and second part 15a, 15b partially surrounds a pylon 12a, 12b and are opposite each other. The arms of the U are opposite each other. A fastening element 38, such as a screw, passes through an arm of the first part 15a to engage in a threaded bore of the corresponding arm of the opposite second part 15b. Each pylon 12, 12a, 12b is enclosed by the first and second parts 15a, 15b fixed by the fixing element 38. Referring to Figure 2, the support means 13 for the cluster 2 are rotationally movable relative to the frame 10. The support means extend between the two pylons 12a, 12b. These are fixed relative to the cluster 2, which follows the movement of the support means 13. The support means 13 comprise two clamping elements 16 onto which the cluster 2 is suspended. Each clamping element 16 is mounted on a support arm 17. In a rest position of the support means 13, the central column of the cluster extends along the longitudinal axis Z. Each support arm 17 also extends along the longitudinal axis Z in the position of rest. In the example shown, each clamping element 16 comprises a base plate 18 mounted at one end of a support arm 17. The support arms 17 are connected by a bar 19 extending along a transverse axis Y. The transverse axis Y is perpendicular to the longitudinal axis Z. The bar 19 is connected at each of its ends to a second end of a support arm 17. The bases 18 are arranged opposite each other. Each base 18 includes a shoulder forming a bearing surface 20 visible in Figure 3 (delimited by dashed lines). The bearing surface 20 is designed to receive a portion of a protrusion 21 provided on the ring 4. The latter comprises two protrusions 21 extending radially from the periphery of the ring 4, each in opposite directions. These protrusions 21 also serve to handle the cluster during the operation of pouring molten metal into the shell. Each protrusion 21 includes a first surface opposite the bearing surface 20 of the corresponding base 18. Each protrusion 21 also includes a second surface 21b which is substantially flush with an external face 18b of the base 18, oriented here towards the support arm 17. The second surface 21b is opposite the first surface of the protrusion which is oriented towards the table 11 in the rest position.Each clamping element 16 includes a tab 22 for clamping a protrusion 21 onto a corresponding base 18. In particular, each tab 22, illustrated in Figure 3, is mounted to rotate about the base 18 along an axis B parallel to the longitudinal axis Z. Each tab 22 is movable between a release position and a locking position in which the protrusion is held in place by the tab 22. Each protrusion 21 is installed between a tab 22 and a bearing surface 20 of a base 18 (along the longitudinal axis Z in its rest position), and when the cluster 2 is mounted on the tooling. This configuration of the clamping elements allows the cluster 2 to be handled only once to secure it when mounting it onto the tooling or when removing it from the tooling 1. Referring to Figure 4, the shakeout tool 1 includes a drive device designed to be remotely actuated and to rotate the support means 13 of the cluster 2 relative to the frame along the transverse axis Y. The drive device includes an operating member 23 which is actuated by a pressure greater than or equal to a predetermined pressure value to rotate the support means 13 along the transverse axis Y. In this example, the operating member 23 is mechanical. The drive device also includes a mechanism 24 for rotating the support means 13, to which the operating member 23 is coupled. The operating member 23 is actuated by The water jet sprayed onto it is intended to remove shell residue. More specifically, the operating member 23 comprises a wheel 25 whose axis is parallel to the longitudinal axis Z. The wheel 25 includes several receiving surfaces 26 on which the water applies the pressure determined to cause the wheel 25 to rotate about the longitudinal axis Z. The receiving surfaces 26 are supported by teeth 27 projecting radially from the periphery of the wheel 25. The receiving surfaces 26 extend in a plane substantially transverse to the direction of the water jet. In this embodiment, the two opposing radial surfaces supported by each tooth are receiving surfaces. The pressure determined to cause the rotation of the operating member 23 is between 150 and 450 bar. The water flow rate can be on the order of 0.7 m³ per hour. This pressure is also applied to the cluster to remove shell residue.With reference to figures 2 and 3, the drive mechanism 24 includes a housing 28 which is mounted on the mounting means 14 via a shelf 29. In particular, the shelf 29 is mounted on one of the supports 15 of the mounting means 14. The drive mechanism 24 here includes a speed reduction element. The latter comprises a rod 30 extending along the longitudinal axis Z. The rod 30 has teeth 31 or notches projecting from its wall and along the longitudinal axis Z. One end of the rod 30 is connected to the operating member 23. The second free end of the rod 30 emerges from the housing 28. The speed reduction member also comprises a toothed pinion 32 which meshes with the teeth 31 of the rod 30. This toothed pinion 32 is coupled to one end of a first drive shaft 33 extending along the transverse axis Y.The second end of this first drive shaft 33 is attached to one of the support arms 17 of the support means 13. In this case, the first drive shaft 33 is attached to the support arm 17, via fastening elements 40, such as screws, which is located near the second pylon 12b that carries the drive mechanism 24. The first drive shaft 33 forms the output shaft and the shaft forms the input shaft of the drive mechanism. The first drive shaft 33 can rotate approximately 360° around the transverse axis Y. Advantageously, but not exclusively, the drive mechanism 24 is made of stainless steel. This allows the drive mechanism 24 to withstand the humid environment of the tooling and to develop sufficient force to rotate the cluster without difficulty. This material is also robust, which helps maintain the cluster in a stable position after each rotation, especially when the cluster is subjected to water pressure. Of course, another material or material alloy with technical characteristics similar to stainless steel is also conceivable. The support means 13 include a guide shaft 34 fixed to the opposite support arm 17, near the first pylon 12a. In other words, each support arm 17 rotates relative to a support 15 fixed to a pylon 12a, 12b. The second part 15b of the support 15, which is mounted on the pylon 12a, includes a bore 39 receiving the guide shaft 34, which pivots freely within it when the first drive shaft 33 rotates about the transverse axis Y. The rotational drive of the operating member 23 by the water pressure drives the first drive shaft 33 in rotation via the rod 30 and the toothed pinion 32. The first drive shaft 33 in turn drives the support means 13 with the cluster 2 along the transverse axis Y. During this rotation, the bar 19, the support arms 17, the bases 18, the clamping elements 16 form a "monobloc" assembly and rotate simultaneously around the axis of rotation Y relative to the fixing means 15 and / or the frame 10. Advantageously, the speed reduction unit has a reduction ratio between 1 / 20 and 1 / 40. Preferably, but not exclusively, the reduction ratio is around 1 / 30. Such a reduction ratio allows for smooth and controlled movement of the cluster 2 during rotation. Furthermore, the reduction unit has low inertia and allows the support means carrying the cluster to stop instantly, presenting the cluster at the correct angle to the fluid jet used to remove shell residue, and remaining stationary even when the cluster is struck by impacts from the fluid jet, in this case, water. Tooling 1 further includes a handwheel 35 which is coaxial with the operating member 23. The handwheel is positioned above the operating member 23 along the longitudinal axis Z. The handwheel 35 allows manual operation of the rotation of the support means holding the cluster 2 relative to the frame. The shakeout tool 1 also allows the cluster to be rotated around the longitudinal axis to facilitate shakeout. In this case, as shown in Figure 4, the shakeout tool includes a second drive shaft 36 extending along the longitudinal axis Z and fixed to the table 11. The second drive shaft 36 is connected to a frame 37 and mounted to rotate relative to the frame 37 around the longitudinal axis Y. The second drive shaft 36 is connected to a remote control element (not shown) that allows the rotation of the second shaft 36 to be controlled remotely as well. The second drive shaft 36 allows rotation up to 360°. We will now describe a method for removing a batch of lost-wax casting parts containing shell residue. This method involves mounting the batch 2 onto the removal tool 1. Initially, the batch 2 is mounted on the support means 13, which are rotatable relative to the frame. To do this, the diametrically opposed protrusions 21 of the batch 2 are installed on the bases 18 of the clamping elements. Each tab 22, which is in its release position—for example, away from the bearing surface 20—is pivoted into the locking position, in which it contacts the second surface 21b of a protrusion 21 and locks the protrusion 21 onto the base 18. Prior to the installation of cluster 2 on frame 10, the latter is arranged in cabin 9 by connecting the second drive shaft 36, mounted on chassis 37, with table 11. The method also includes spraying a fluid jet towards the drive device at a pressure greater than or equal to a predetermined pressure value, remotely actuating the drive device which rotates the support means about the second axis. The fluid jet is also used to remove shell residue by impact. In particular, a water jet is sprayed, by means of a spraying element 40 (see Figure 4), towards the cluster 2 with the support means 13 in the rest position, to remove the shell residue by impact. When the operator wishes to access other areas of the cluster 2, for example, below it, to remove shell residue, they direct the water jet towards the operating member 23.The pressure of the sprayed water jet against the receiving surfaces 26 of the operating member 23 causes the rotation of the rod 30 whose teeth 31 mesh with the pinion 32 which is rotationally fixed to the first drive shaft 33. The first drive shaft 33, also rotationally fixed to the support arm 17, drives the latter in rotation along the transverse axis Y in a retracted position of the support means 13. Simultaneously, the cluster 2 pivots around the transverse axis Y. Similarly, when the operator wishes to access other areas, for example diametrically opposite the crown, the operator activates a piloting element, outside the cabin, to rotate the entire frame 10 via the second drive shaft 36 around the Z axis. Thus, the tooling 1 installed in the cabin 9 is remotely operated by an operator who is outside the cabin so that the water sprayed on the cluster can, on the one hand, activate the rotation of the cluster when necessary, and on the other hand, reach all areas of the cluster to remove residues.

Claims

DEMANDS 1. Shake-off assembly comprising tooling (1) for shaking off a cluster (2) of lost-wax castings containing shell residue and a fluid spraying element (40) for spraying a jet of fluid (F), the tooling comprising: - a frame (10) extending along a first axis (Z), - support means (13) connected to the frame (10) and configured to support the cluster (2) of parts, the support means (13) being rotationally mobile relative to the frame (10), around a second axis (Y) perpendicular to the first axis (Z), and - a drive device (23, 24) configured so as to be remotely actuated by the fluid jet (F) at a pressure greater than or equal to a determined pressure value and to drive the support means (13) in rotation along the second axis (Y), the fluid jet (F) being intended to remove the shell residues by impact.

2. Shake-off assembly according to the preceding claim, characterized in that it comprises a cluster (2) of lost-wax casting parts having shell residues (3) and mounted movably in rotation relative to the frame (10) on the support means (13), the fluid jet (F) being further intended to remove the shell residues by impact.

3. De-knocking assembly according to any one of the preceding claims, characterized in that the support means (13) are mounted on the frame (10) by means of fastening means (14) removably fixed to the frame (10).

4. Release assembly (1) according to any one of the preceding claims, characterized in that the drive device comprises an operating member (23) and a drive mechanism (24), the support means (13) being driven in rotation by the operating member (23) via the drive mechanism (24).

5. A release assembly (1) according to any one of the preceding claims, characterized in that the frame (10) comprises at least one pylon (12, 12a, 12b) extending along the first axis (Z), the fastening means (14) comprising at less a support (15) mounted on the pylon (12, 12a, 12b), and the support means (13) comprising at least one clamping element (16) intended to hold the cluster (2) by at least two protrusions (21) and to rotate relative to the support (15) around the second axis (Y).

6. Unblocking assembly according to any one of the preceding claims, characterized in that the support means (13) are integral with at least one first drive shaft (33) extending along the second axis (Y), the first drive shaft being driven in rotation by the drive mechanism (24).

7. Debarking assembly (1) according to the preceding claim, characterized in that the drive mechanism (24) comprises a reduction member with a rod (30) having teeth (31) meshing with a toothed pinion (32), the toothed pinion (32) being coupled to the first drive shaft (33).

8. Release assembly (1) according to any one of the preceding claims, characterized in that the operating member (23) comprises a wheel provided with teeth (27) projecting from its periphery, the teeth (27) having receiving surfaces (26) on which the determined pressure is applied.

9. Detachment assembly (1) according to any one of the preceding claims, characterized in that the determined pressure value is between 150 and 450 bars.

10. Release assembly (1) according to any one of claims 5 to 9, characterized in that the frame (10) comprises a table (11) from which the pylon extends, a second drive shaft (36) integral with the table (11) extending along the first axis (Z), the second drive shaft (36) being able to rotate about the first axis (Z) so as to drive the rotation of the frame (10) relative to a chassis (37).

11. A method for removing a cluster (2) of lost-wax casting parts containing shell residue, the method comprising the following steps: an installation of the cluster (2) on support means (13) of a detachment tool of an assembly according to any one of claims 1 to 10, the support means (13) being rotationally mobile relative to the frame (10), a spray of a fluid jet towards the drive device at a pressure greater than or equal to a predetermined pressure value, remotely actuating the drive device which rotates the support means (13) along the second axis (Y), and 5 - spray the fluid jet evenly onto the cluster (2) to remove by impact the shell residues of the cluster.