JP2007021708A - Method and device for blasting abrasive material to rotation symmetrical member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide method and device for blasting an abrasive material to an abrasive material spraying object without damaging the object and uniformly blasting the abrasive material to the object with little time and cost. <P>SOLUTION: By this method, the abrasive material is blasted to a rotation symmetrical member, more particularly, a metal member. The method includes steps of: putting each member 1 in an abrasive material blasting chamber 2; moving each member 1 along a carrying path through the abrasive blasting chamber 2; blasting the abrasive material to each member 1 from three surfaces, that is, upper surface and both of side surfaces by an abrasive material blasting means; rotating each member 1 around the rotary axis while passing each member 1 through the abrasive material spraying chamber 2; turning the rotary axis sideways in relation to a carrying direction of each member 1 at the time; and taking out each member 1 blasted with the abrasive material at an exit of the abrasive material blasting chamber 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for sand removal of cast iron members, sand removal of light metal members, deburring and surface improvement, scale removal of cast and forged members, ball spraying of metal members, and an apparatus for carrying out this method. About.

  In the prior art, abrasive blowing devices for members, in particular metal members, are known, which consist of a chamber which is used to protect against dust and has a device for accelerating the abrasive. There are also devices that capture and transport the abrasive. Abrasive spraying means a finishing method in which a solid and / or liquid abrasive material impinges on a workpiece to be processed at high speed, i.e. an abrasive spray object. According to the overwhelming effects or the purpose of abrasive spraying, which are regarded as dominant respectively, the abrasive spraying method can be incorporated into deformation, separation or material property changes as a main group. To accelerate the abrasive to the required speed, it is possible to apply the abrasive with a liquid or gaseous carrier material or with a centrifugal impeller. The most known abrasive spray methods are sand blasting, shot blasting and abrasive spray cutting. During the abrasive spraying, cleaning with an abrasive is performed for the purpose of removing rust, scale and other impurities from the surface of the workpiece to be processed. For example, compressed air is used as the carrier material. During shot peening, a distinction is made between deformation abrasive spraying and curing spraying. Deformation abrasive spraying is used for forming or wetting by creating plastic deformation and internal compressive stress in the surface area of the workpiece. Curing abrasive spraying is a cold deformation method and is used to generate internal compressive stress in a range close to the surface of the abrasive spraying object to improve the endurance fatigue limit, corrosion resistance or wear resistance.

  In the prior art, it is known to deburr, for example, cast metal parts such as brake discs or brake drums by abrasive blowing, to remove scale and to remove residual foundry sand. The abrasive is applied by a turbine. A suitable abrasive spraying object, i.e. a brake disc or brake drum, is put into the device, circulated in the device and at the same time conveyed in the length direction of the device, e.g. configured as a drum. The member is supplied via a vibrating rod, for example. Working with such a method or such a device is disadvantageous in that damage to the surface of the brake disc or brake drum occurs. This is because the members collide with each other and come into contact with each other during circulation. In addition, the abrasive material is not sprayed precisely and uniformly.

  It has already been proposed that suitable members, for example brake discs or brake drums, to which the abrasive is to be sprayed are individually attached to the cradle and transported through the abrasive spraying device by means of an overhead chain conveyor. Such a method is very expensive. This is because the individual workpieces must be hung individually and removed from the device after the abrasive is sprayed. Further, in this case, the abrasive does not hit the member uniformly. Overall, this method is very time consuming and expensive.

  When the abrasive is sprayed on such a workpiece, spraying with steel grains usually made of cast steel is used.

  Starting from this prior art, the problem underlying the present invention is that the abrasive spraying object can be sprayed onto the object without damaging the abrasive spraying object. It is an object to provide a method and an apparatus that can perform uniform abrasive spraying on the surface and can perform abrasive spraying that is advantageous in terms of time and cost.

In order to solve the technical problem of this problem, the following method steps are proposed. That is, put individual members into the abrasive spray chamber,
Move the member along the transport path through the abrasive spray chamber,
Abrasive material is sprayed onto the member by means of abrasive material spraying means from three surfaces, that is, the upper surface and both side surfaces,
Rotate the member around its axis of rotation while passing through the abrasive spray chamber, with the axis of rotation oriented transversely to the conveying direction of the member,
At the outlet of the abrasive spray chamber, the individual parts sprayed with the abrasive are removed.

  According to the invention, the members to which the abrasive is to be sprayed are individually put into the abrasive spray chamber via suitable conveying means. By another conveying means, the member is moved through the abrasive blowing chamber along the conveying path. Since the abrasive is introduced into the abrasive spray chamber from three sides, the head side and both sides, the member is uniformly sprayed with the abrasive from the side and head side. While passing through the abrasive spray chamber, the member is rotated around its axis of rotation so that a completely uniform abrasive spray is made during the passage, and this spraying takes place in a little more time and cost. be able to. From the outlet of the abrasive spraying chamber, the members can be taken apart again and taken out to a storage place or a packaging place via a conveying means provided later, for example. For example, if the members are often configured as brake discs that are internally ventilated and have slits that open outwardly, the edges of these members stand on suitable transport means and the abrasive spray chamber Since the member can be rotated about its axis when passing through the member, the member is sprayed with the abrasive uniformly from both sides, and the abrasive is uniformly sprayed from the head side to the edge of the member. Similarly, for example, a brake drum can be processed.

  The member is placed on the conveying means by the conveying means, moved by the conveying means through the abrasive spray chamber, acceleration or braking means acts on the member, and the movement of the member by the conveying means is accelerated or decelerated through this means. It is preferable that the member is braked, thereby causing the member to roll along the transport path, and the rolling motion is superimposed on the transport motion generated by the transport means.

  The conveying means can be, for example, a conveyor belt, and the member is supported on the conveyor belt by its peripheral surface. Therefore, the member can be conveyed in the conveying direction through the abrasive blowing chamber by the conveying means, and can be rotated around its rotation axis. In order to perform the rotation, acceleration means or braking means as much as possible is provided and acts on an appropriate member, whereby the member is accelerated or braked by the conveying means on which the member is placed, whereby the member is moved along the conveying path. The rolling motion is caused to be superimposed and the transporting motion generated by the transporting means, for example a conveyor belt, is superimposed.

  Further, the passing speed of the member passing through the abrasive blowing chamber changes the transport speed of the transport means and / or changes the inclination of the transport path or the transport means in the transport direction or vice versa, and is transverse to the transport direction. It may be adjusted by changing the inclination of the conveying path or conveying means.

  Further, it is preferable that the member is inclined laterally with respect to the conveying direction so that the side surface is placed on the support column that exerts a frictional force on the side surface.

  In this configuration, means for generating a frictional force is provided on a side surface substantially orthogonal to the contact surface of the conveyor belt or other conveying means. When the member is inclined laterally with respect to the conveying direction, the member abuts against the corresponding side surface under the action of a specific force, and the frictional force is exerted on the side surface of the member by the action of this force. By changing the inclination, the braking force can be increased or decreased so that the speed at which the member rolls is increased or decreased.

  Further, the conveying means is reciprocated within a limited range transverse to the conveying direction.

  By the reciprocating movement of the conveying means within a limited range transverse to the conveying direction, the abrasive does not necessarily hit the conveying means at the same location, and therefore the abrasion means or grooves are not formed in the conveying means. . Accordingly, the life of the conveying means is improved.

  In order to solve the problems relating to the apparatus, according to the present invention, the apparatus comprises an abrasive spraying chamber having an inlet at one end and an outlet at the other end, and a conveying means is provided in the abrasive spraying chamber. The member to be sprayed can be separated on the inlet side and placed on the conveying means, the member can be separated on the outlet side and taken out from the conveying means, and the abrasive spraying chamber can be It has a means to apply abrasive to the member as an object so that the abrasive is applied to both sides of the abrasive spraying object and the head side of the abrasive spraying object far from the conveying means. The means for applying the abrasive is oriented, and the movement means is provided in the abrasive blowing chamber in addition to the conveying means, and the rotating means by which the abrasive spraying object is superimposed on the conveying movement by the conveying means. Line motion around rotation axis It can be or do.

  In this case, it is preferable that the conveyor means circulates.

  In order to automate the equipment and thereby enable the abrasive spraying process to be carried out at a lower cost, an inflow conveying means is provided on the inlet side of the conveying means, and the inflow conveying means allows the members to flow in the side. It is possible to move from a flat lying position placed on the means to an inclined upright conveying position, so that the member is supported on the conveying means and can be transferred to the conveying means. .

  Further, the abrasive spray chamber is provided on the upper surface and the side surface of the outer jacket of the abrasive spray chamber as a means for applying the abrasive, and in some cases, distributed in the length direction of the abrasive spray chamber. I have a centrifugal impeller.

  Furthermore, it is preferable that the contact surface of the conveying means on which the peripheral surface of the abrasive spray object is supported is inclined laterally with respect to the conveying direction.

  In that case, it is preferable that the inclination of the conveying means can be adjusted.

  Furthermore, it is preferable that an operating device is provided between the gantry of the apparatus and the abrasive spraying chamber, and the abrasive spraying chamber can be rotated within a limited range around the longitudinal axis by the operating device.

  This allows, for example, the conveying means itself or other components within the abrasive spray chamber to be adjustable and not changeable, since the entire abrasive spray chamber is rotated about its longitudinal axis. Thus, the inclination of the conveying means (conveyor belt) or the relative inclination of the moving means can be adjusted, whereby the residence time and rotational speed of the member to which the abrasive is to be sprayed can be changed.

  Further, it is preferable that the motion means is formed by guide pieces provided laterally above the transport means, and the side surface of the abrasive spraying object is in contact with these guide pieces.

  In this case, it is preferable that the guide piece is provided at a position higher than the radius of the conveying means abrasive spray object from the conveying means.

  Furthermore, it is preferable that the guide piece has a contact surface for a member having a large frictional resistance.

  Furthermore, the abrasive spray chamber can be adjusted in inclination in the conveying direction.

  As a result, the inclination of the conveying means, for example, the conveyor belt, is variable, so that the passage speed of the member passing through the abrasive spray chamber can be changed.

  For the sake of realization, one end of the abrasive spray chamber is preferably supported by a swing support having a swing axis that is horizontally oriented transversely to the transport direction, and the other end of the abrasive spray chamber. As close as possible to the outlet, it is preferably connected to the stationary gantry part via the adjusting element so that the abrasive spray chamber can be swung within a limited range around the rocking support. .

  The adjusting element can then be at least one screw shaft with an electromechanical screw shaft drive.

  Further, it is preferable that the conveying means is provided so as to be movable sideways in the abrasive spray chamber.

  As a result, the rollable member to which the abrasive is to be sprayed does not necessarily move on the same track, but always comes into contact with another area of the conveying means by the movement of the conveying means, so that the conveying means, in particular the conveyor belt, receives only slight wear. Can be. At that time, it is preferable that the conveying means can be moved laterally by vibrating by the screw shaft reciprocating element.

  A particular advantage of this device is in particular that the lifetime is increased by lateral movement of a conveyor belt or the like. The entire device can rotate by a certain angle because it changes the frictional force acting on the passing member and causing its rotation relative to the conveying means. In order to further increase the passing speed, the inclination of the conveyor belt can also be varied within limits. Since this apparatus can perform uniform abrasive spraying onto the abrasive spraying object from three different sides, the abrasive can be sprayed onto the abrasive spraying object at high quality at a low cost. . The method according to the invention or the device according to the invention is particularly suitable for brake drums or brake discs and wheel bodies or other rotationally symmetric members. The members are individually passed through the device via a conveyor belt with constant rotation, with the abrasive being sprayed in a predetermined manner from above and on both sides. Special control of pass speed and abrasive spray strength is variable via drum tilt and belt feed. Abrasive spraying on the passing principle provides operational and cost advantages. In this way, fully automatic manufacturing is performed with high finishing sustainability by the passing principle. Further, by integrating the abrasive spraying process into an automated production line, operating costs are also reduced. Temporary storage and component tracking is not required. This is because the method and apparatus operate according to the first-in-first-out principle. Manual handling operations are greatly reduced or avoided. Appropriate members are individually passed through the device in a row, so that a more reliable workpiece transfer is performed. A predetermined uniform abrasive spray is applied to all members, and no impact damage is caused by the members in contact with each other. The rotational speed of the member can be changed by adjusting the inclination of the abrasive spray chamber around the longitudinal axis, for example, 30 ° to 50 °. In such a device, a discharge slit for sand, scale and fine particles can be provided in the lower area of the device. The abrasive material sucked out of the chamber can be purified and circulated back to the centrifugal impeller and returned again.

  Embodiments of the invention are described in detail below.

  The drawing shows a device for spraying abrasive material onto a rotationally symmetric member 1, such as a brake disc for an automobile. For example, the apparatus shown in FIGS. 1 and 2 comprises an abrasive spray chamber 2, an inlet 3 and an outlet 4. A supply device is provided on the inlet side as much as possible, and the members are separately supplied to the device in a correct posture by this device. At the outlet 4 of the device 4, a device is preferably provided for moving the components apart and moving them to another processing place, packaging place or storage place. In the abrasive blowing chamber 2, there are provided conveyor means 5 in the form of conveyor belts, and the members 1 to which the abrasive is to be sprayed are placed separately on the conveyor means on the inlet side and these on the outlet side. Are separated from the conveying means. The abrasive spray chamber 2 has means 6 for applying the abrasive to the abrasive spray object. This means is, for example, a centrifugal impeller.

  These means of applying the abrasive are only partially seen and schematically shown in the drawings. These means 6, for example the centrifugal impellers, are arranged in the embodiment so that the three centrifugal impellers spray abrasive material to the left of the abrasive spray object to be placed on the conveying means 5, and accordingly 3 Since two other centrifugal impellers are arranged to face each other, the abrasive is sprayed on the right side, and another centrifugal impeller is provided above the head, so that it is far from the conveying means 5 On the side, the abrasive spray object 1 is sprayed with the abrasive. Since the abrasive spray chamber 2 is open downward, the abrasive can exit through the slit and be discharged into the abrasive transport groove 7. By means of the abrasive conveying groove 7, the abrasive is supplied to the regenerator or separator, and the cleaned abrasive is then supplied again to the process and is thus entered by the centrifugal impeller 6 into the abrasive spray chamber.

  In particular, as can be seen from FIGS. 4 to 7, in the abrasive spray chamber, in addition to the conveying means 5, a moving means 8 is provided laterally, and the member 1 is moved by the moving means 5 in the direction of the arrow 9. Rotational motion around the rotational axis superimposed on the transport motion performed in the above.

  FIG. 3 shows the upper side and the lower side of the conveying means 5. The edge of the member 1 is on the upper side 5. As shown in FIGS. 6 and 7, the contact surface formed by the conveying means 5 for the abrasive spray object 1 is inclined laterally with respect to the conveying direction, and this inclination can be adjusted to be different. it can. The movement means 8 is formed by a guide piece provided laterally above the conveying means 5, and the side surface of the abrasive spraying object 1 contacts these movement means 8 as shown in FIGS. It touches. These movement means 8 in the form of guide pieces are constructed such that they have sufficient frictional resistance, so that when the abrasive spray object 1 is moved in the conveying direction 9 by the conveying means 5, this polishing means 8 Since the material spraying target object 1 is supported by these guide pieces on the side surface, the material spraying target object 1 is caused to rotate as indicated by the motion arrow 10 by the frictional force. The guide piece 8 is stationary, and is therefore fixed and fixed in the abrasive spray chamber 2 with respect to the gantry.

  As can be seen from FIGS. 6 and 7 in particular, the steep inclination of the conveying means 5 provides a small feed rate for the abrasive spraying object, and a large frictional force at the moving means 8, particularly at the guide piece. . Therefore, a small frictional force is obtained for the conveying means 5 and a large frictional force is obtained for the guide piece 8. As a result, the residence time of the abrasive spraying object in the abrasive spraying chamber 2 is increased, and accordingly, a high rotational speed of the abrasive spraying object 1 is obtained when passing through the abrasive spraying chamber. In FIG. 7, at a steep lean angle, the frictional force between the abrasive spraying object 1 and the conveying means 5 is large, and the frictional force between the abrasive spraying object 1 and the guide piece 8 is small. In this case, a high feed rate is obtained, and the abrasive spraying object 1 has a small rotational speed over the course of the abrasive spraying. In particular, all the above-mentioned members are combined with the abrasive spray chamber 2 so that the inclination adjustment of the conveying means 5 and the guide piece 8 is performed by turning the abrasive spray chamber 2 around its longitudinal axis. ing.

  As can be seen in particular from FIGS. 3, 14 and 15, an operating device 12 is provided between the gantry 11 of the apparatus and the abrasive spraying chamber 2, and this operating device causes the abrasive spraying chamber 2 to move along its vertical axis. It can rotate in a limited range around. The operating device 12 is, for example, a drive screw shaft, and the abrasive spray chamber 2 can be appropriately adjusted by this screw shaft. The abrasive spray chamber 2 is supported on a support roller 13. Further, as shown in FIGS. 2 and 10-13, the abrasive spray chamber 2 is adjustable so that its inclination in the conveying direction and hence the inclination of the conveying means 5 therein is adjusted. For this reason, the abrasive spraying chamber 2 is supported by a swinging support body 14 supported so as to be swingable around an axis that is oriented horizontally in the direction transverse to the conveying direction near the entrance. Near the other end, i.e. near the outlet, the abrasive spray chamber 2 is coupled to the stationary pedestal portion 16 via an adjustment element 15, which causes the abrasive spray chamber 2 to swing around the swing support 14. It can be moved, and therefore the tilt can be adjusted. The adjusting element 15 can be realized by, for example, a screw shaft having a screw shaft driving device.

  The conveying means 5 shown in detail in FIGS. 8 and 9 comprises a conveyor belt wound around a driving roller 18, and the roller 17 is driven and the roller 18 serves as a tensioning wheel for tensioning the belt 5. It is configured.

  In order to prevent the abrasive spraying object 1 from being always placed on the same portion of the conveyor belt when the conveying means 5 is started, the conveying means 5 is provided so as to be able to move laterally. A roller moving device 19 is provided. The roller moving device is indicated at 21. Since the roller moving device is provided on the driving roller 17 and the turning roller 18, the conveying means 5 can be moved laterally, for example, vibrationally or periodically, and thus can be reciprocated, so that the abrasive spraying object 1 can be moved. The mounting range is always in a different place, whereby a high life of the conveying means 5 is obtained. This is because the conveying means does not always act on the same place.

  In the description of the embodiment, the abrasive spraying object 1 is rotated by braking, but it is also possible to rotate the abrasive spraying object by an accelerating motion with respect to the conveying means. For this reason, for example, a guide piece (motion means) 8 is used. However, since it is formed by a conveyor belt having a circulation speed faster than that of the conveyor means 5, the rotational movement of the abrasive spraying object 1 on the conveyor means 5 is performed.

  The invention is not limited to the examples, but is variable within the scope of the disclosure.

  Individual features and combinations thereof disclosed in the specification and / or drawings are considered important to the invention.

  Fig. 2 shows a perspective view of the main part of the device according to the invention.   A side view of the device is shown.   Fig. 3 shows the device viewed in the direction of arrow Z in Fig. 2;   The apparatus seen from the entrance side is shown.   The details of the device are shown schematically.   Figure 2 schematically shows another detail of the device.   Fig. 7 shows another detail of the device taking a different posture than Fig. 6;   Details of the device are shown in side view.   9 shows details of the device as seen in the direction of the arrow W in FIG.   The end face of the details of the device is shown.   Fig. 11 shows a detailed side view of the device according to Fig. 10;   Figure 2 shows the end face of another detail of the device.   Fig. 13 shows a detailed side view of the device according to Fig. 12;   Another detail of the device is shown in a longitudinal view.   The details according to FIG. 14 are shown in side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Member 2 Abrasive material spraying chamber 3 Inlet 4 Outlet 5 Conveying means 6 Abrasive material spraying means 8 Movement means

Claims (20)

A polishing material spraying method for rotationally symmetric members by an abrasive material,
Put the individual parts into the abrasive blowing chamber,
Move the member along the transport path through the abrasive spray chamber,
Abrasive material is sprayed onto the member by means of abrasive material spraying means from three surfaces, that is, the upper surface and both side surfaces,
Rotate the member around its axis of rotation while passing through the abrasive spray chamber, with the axis of rotation oriented transversely to the conveying direction of the member,
A method comprising the step of removing individual parts sprayed with abrasive at the outlet of the abrasive spray chamber.   The member is placed on the conveying means by the conveying means, moved by the conveying means through the abrasive spray chamber, and acceleration or braking means (8) acts on the member (1), through which the conveying means ( The movement of the member (1) by 5) is accelerated or braked, thereby causing the member (1) to roll along the conveyance path, so that the rolling movement is superimposed on the conveyance movement generated by the conveyance means (5). The method of claim 1, characterized in that The passage speed of the member (1) passing through the abrasive spray chamber (2) is
Changing the conveying speed of the conveying means (5) and / or changing the inclination of the conveying path or conveying means (5) in the conveying direction or vice versa;
3. Method according to claim 1 or 2, characterized in that it is adjusted by changing the inclination of the transport path or transport means (5) transversely to the transport direction.   The member (1) is braked by inclining the member (1) laterally with respect to the conveying direction and causing the side surface to rest on a support (8) that exerts a frictional force on the side surface. The method according to 2 or 3.   5. The method as claimed in claim 2, wherein the transport means is reciprocated in a limited range transversely to the transport direction. An abrasive spraying device for a rotationally symmetric member (1) by an abrasive,
The apparatus consists of an abrasive spray chamber (2) having an inlet (3) at one end and an outlet (4) at the other end,
The conveying means (5) is provided in the abrasive spray chamber (2), and the member (1) to which the abrasive is to be sprayed is separated on the inlet side and can be placed on the conveying means. ) Are separated on the exit side and can be taken out from the conveying means,
The abrasive spray chamber (2) has means (6) for applying the abrasive to the member (1) as the abrasive spray object, and the abrasive is on both sides of the abrasive spray object (1). And the means for applying the abrasive is oriented so that it is applied to the head side of the abrasive spray object (1) far from the conveying means (5),
In the abrasive spraying chamber (2), a motion means (8) is provided in addition to the transport means (5), and the abrasive spray object (1) is transported by the transport means (5) by this motion means. A device in which a rotational motion superimposed on the motion is or can be performed around the axis of rotation.   7. A device according to claim 6, characterized in that the conveying means (5) is a circulating conveyor belt.   Inflow conveyance means is provided on the inlet side of the conveyance means (5), and the inflow conveyance means causes the member (1) to move from a flat lying position where the side surface is placed on the inflow conveyance means to an inclined upright conveyance position. 8. A device according to claim 6 or 7, characterized in that it is transferable, so that the member (1) can be transferred to the conveying means (5) with its peripheral surface supported on the conveying means (5). .   The abrasive spray chamber (2) has centrifugal impellers provided on the upper surface and side surfaces of the outer jacket of the abrasive spray chamber (2) as means for applying the abrasive (6). A device according to one of claims 6-8.   1 of Claim 6-9 characterized in that the contact surface of the conveying means (5) on which the peripheral surface of the abrasive spraying object (1) is supported is inclined laterally with respect to the conveying direction. Device.   Device according to claim 10, characterized in that the inclination of the conveying means (5) is adjustable.   An operating device (12) is provided between the frame (11) of the apparatus and the abrasive spraying chamber (2), and the abrasive spraying chamber (2) is limited around the longitudinal axis by the operating device. 12. A device according to claim 10 or 11, characterized in that it can be rotated in a range.   The movement means (8) is formed by guide pieces provided laterally above the conveying means (5), and the side surface of the abrasive spraying object (1) is in contact with these guide pieces. Device according to one of claims 6 to 12, characterized in that   Device according to claim 13, characterized in that the guide piece (8) is provided at a height greater than the radius of the abrasive spray object (1) from the conveying means (5).   Device according to claim 13 or 14, characterized in that the guide piece (8) has an abutment surface for a member (1) having a high frictional resistance.   14. A device according to claim 6, wherein the abrasive spray chamber (2) is adjustable in inclination in the conveying direction.   One end of the abrasive spraying chamber (2) is supported by a swinging support (14) having a swinging axis that is oriented horizontally in a direction transverse to the conveying direction, and the abrasive spraying chamber (2) The other end is coupled to the stationary pedestal part (16) via the adjustment element (15), which limited the abrasive spray chamber (2) around the oscillating support (14). Device according to claim 16, characterized in that it can be swung in a range.   18. Device according to claim 17, characterized in that the adjusting element (15) is at least one screw shaft with an electromechanical screw shaft drive.   Device according to one of claims 6 to 18, characterized in that the conveying means (5) are provided so as to be able to move sideways in the abrasive blowing chamber (2).   20. The device according to claim 19, characterized in that the conveying means (5) can be moved laterally by vibrating with a screw shaft reciprocating element.

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