JP2010514922A - Method and apparatus for coating hollow bodies - Google Patents

Abstract

In a method for coating a rotationally symmetric hollow body, a coating material is applied onto the surface to be coated using a dispensing device, the process being repeated until a complete coating of the surface proceeds as follows: Implemented:
-To move the dispensing device relatively linearly relative to the hollow body-To rotate the dispensing device relative to the hollow body by a defined angle [Selection] Fig. 1

Description

  The present invention relates to a method and apparatus for coating a hollow body.

  These must be coated several times in order to create high quality surfaces on the components. In this case, the material is regularly applied on the supporting component with a layer with a value of only a few μm, which increases the wear resistance, for example, or provides a certain property (for example electrical conductivity) on the component surface. It is for granting.

  Various coating methods are known, in particular thermal coating methods are used, in which the coating material is melted and subsequently regularly sprayed with a stream of compressed air or other gas, It is transferred onto the surface to be coated. Known thermal coating methods are plasma coating, (high speed) flame spraying, wire arc spraying.

  From Patent Document 1, a wire arc spraying apparatus for coating a hollow body is known.

  The wire arc spraying device disclosed there has a burner shaft in the form of a hollow shaft that is inserted into the hollow space to be coated. A radially oriented nozzle is provided at the lower end of the burner shaft through which molten coating material droplets are blown out using compressed air supplied through the hollow interior of the burner shaft. The

  A replenishing device having two wire rolls is fixed to the burner shaft on the upper side of the burner shaft. Starting from these wire rolls, the two wires are guided to the end of the burner shaft parallel to the longitudinal axis of the burner shaft. At the tip, an electric high voltage is used to generate an arc between the ends of the two wires, and this arc melts the wire material. The molten wire drop is then captured by the compressed air stream and blown out through the nozzle. The replenishing device is for continuously supplying the coating material to the burner.

  During the coating process, the burner shaft is continuously driven in rotation and simultaneously moved linearly in the hollow body. The superposition of these two movements results in a helical coating process.

  The disadvantage of the device of Patent Document 1 is the high labor and cost of the structure, which means that the entire unit consisting of the burner shaft and the replenishing device is continuously and at a high rotational speed (usually 100 to 150 per minute). It is associated with the fact that it must be driven to rotate.

  Furthermore, it is known from this prior art that the hollow body itself is driven to rotate instead of the burner shaft. Such a configuration has been demonstrated with a hollow body that is small, lightweight and especially formed with rotational symmetry, and does not generate significant unbalance during rotation. For complex, non-rotationally symmetric components, such as cylinder crankcases, this process is associated with great effort and cost for balancing the components. Cylinder crankcases have the difficult situation that they usually have a plurality of cylinders to be covered and the rotational axis of each cylinder also changes, which requires a new balance adjustment of the unit.

German Patent Application Publication No. 19841617

  Thus, starting from this prior art, the problem underlying the present invention presents an improved method and an improved apparatus for coating hollow bodies, in which at least one disadvantage known from the prior art is avoided. It is to be. In particular, a device that allows a simpler construction in structure should be presented.

  This problem is solved by a method and device according to the independent claims. Advantageous embodiments are the subject of the dependent claims.

  The idea that forms the basis of the present invention is not to carry out the covering of the hollow body in the form of a spiral by superposition of a linear motion and a rotational motion, but in an intermittent linear motion.

  Therefore, according to the invention, it is intended to first coat the surface to be coated with a first region that moves linearly, in which case the dispensing device for the coating material and the hollow body are moved linearly relative to one another. The For this purpose, at least one linear drive is provided according to the invention, with which the distributor and / or the hollow body are moved linearly and thereby moved relative to each other. After reaching the end of the stroke, which is usually based on reaching the end of the linear extension range of the surface to be coated, in a subsequent step, the distributor is set at a predetermined angle value relative to the hollow body. The rotation is preferably made about the axis of the linear motion previously performed. For this purpose, at least one rotary drive for the distributor and / or the hollow body is provided.

  After rotation for a defined angle, the surface to be coated of the second part can be coated, so that the linear relative movement of the dispensing device with respect to the hollow body is again carried out. This can be done during the return movement of the dispensing device relative to the hollow body, and thus in the opposite direction to the movement during the coating of the first part. Alternatively, the dispensing device may be in an inoperative state, i.e. it is turned back without applying a coating material to the starting side of the hollow body, and the coating of the second part takes place in a subsequent stroke in the same direction as the previous coating stroke. obtain. In this way, if necessary, it is possible to achieve a coating carried out only in the same direction of movement.

  The linear relative movement of the non-actuated dispensing device with respect to the hollow body can take place according to the invention before, during or after the rotational movement.

  The above method steps are repeated until all the surfaces to be coated have been processed, this surface necessarily does not have to be completely connected and should not be coated by intermittent coating. The surface portion can also be easily left.

  With the appropriate design of the control means of the rotary drive, a two-part covering (overlap) that is successively covered can be chosen arbitrarily. Multiple layers of coating can also be achieved in a single coating process with an appropriately sized covering.

  The linear drive and the rotary drive can drive the dispensing device and / or the hollow body directly or indirectly. It can be intended in particular to provide a fixing device for the hollow body, with which the hollow body is positioned reliably and accurately. If a linear drive and / or a rotary drive is provided for the movement of the hollow body, the movement of the hollow body can also be performed by moving the fixing device using the drive, the drive being fixed A hollow body positioned on the apparatus is taken along.

  In an advantageous embodiment of the invention, the linear drive is formed as a two-axis or three-axis linear drive. This allows the dispensing device to be added to a linear stroke movement and moved in one or two other directions, where the two or three directions are preferably oriented perpendicular to each other. With such a configuration of the device according to the invention, the spacing between the dispensing device and the surface to be coated can be set to an optimum dimension for the coating process, but this often involves the eccentric position of the dispensing device in the hollow body. Must be accepted. This is a problem in devices such as those known from the prior art due to the continuous rotation of the dispensing device or the hollow body, which varies continuously between the maximum and minimum values and requires great effort and cost. Such a correction can be achieved much more easily with the device according to the invention. This spacing is only corrected during the intermittent rotation of the distributor relative to the hollow body. In contrast, no such correction is necessary during the coating process in which the dispensing device is preferably moved parallel to the surface of the hollow body.

  Of course, the two-axis or three-axis linear drive can consist of individual elements that can be spatially and structurally separate from one another and can preferably be controlled by a central controller.

1 shows an overview of a device according to the invention for coating a hollow body. It is a figure which shows the aspect of the exercise | movement progress according to 1st Embodiment of this invention with a graph. It is a figure which shows the aspect of the exercise progress according to 2nd Embodiment of this invention with a graph.

  Next, the present invention will be described in detail based on embodiments shown in the drawings.

  FIG. 1 shows a hollow cylinder 1 as a hollow body, the inner surface of which is sprayed with a molten coating material using a spray lance 2 as a distributor.

  The structure and function system of the spray lance 2 are basically known from the prior art.

  The spray lance 2 is moved into the hollow cylinder 1 by means of the linear drive 3, where it is moved along the longitudinal axis of the hollow cylinder 1 over its entire longitudinal extent.

  The hollow cylinder 1 itself is connected to the rotational drive unit 4, and the rotational drive unit 4 intermittently rotationally drives the hollow cylinder 1 according to the present invention as seen from the motion graphs of FIGS. 2 and 3.

  Control of both the drive units 3 and 4 is performed using the control device 5.

  2 and 3 show the movement of the blowing lance 2 relative to the hollow cylinder 1 as a schematic diagram with two alternative embodiments. At this time, the linear relative momentum (s) along the vertical axis of the hollow cylinder 1 is shown on the vertical axis, and the rotation angle (α) is shown on the horizontal axis.

  In the control of the device according to FIG. 2, the inner surface of the hollow cylinder 1 is covered in both the ascending stroke and the descending stroke of the blowing lance 2. This is symbolized by arrows in the vertical part of the curve in the graph according to FIG. After each coating stroke, the hollow cylinder 1 is rotated by a defined angle value (Δα) using the rotary drive 4. Subsequently, a further coating process of the spray lance 2 is carried out.

  In the control of the device according to FIG. 3, the inner surface of the hollow cylinder 1 is covered only during the upward stroke. Directly following the ascending stroke, a descending stroke (dotted line portion of the curve) is carried out, and in this descending stroke the spray lance 2 is inactive, ie no coating material is applied. Only after the lowering stroke is completed, the hollow cylinder 1 is rotated by the desired rotational angle value before the start of a new coating cycle.

DESCRIPTION OF SYMBOLS 1 Hollow cylinder 2 Spraying lance 3 Linear drive part 4 Rotation drive part 5 Control apparatus

Claims (5)

A method for coating a hollow body (1), wherein the coating material is applied onto the surface to be coated using a dispensing device (2),
Iterating to complete coverage of the surface and proceeding as follows:
-Moving the dispensing device (2) relatively linearly relative to the hollow body (1);
Rotating the dispensing device (2) relative to the hollow body (1) by a defined angle.   2. Method according to claim 1, characterized in that the dispensing device (2) is moved linearly and / or rotationally.   3. Method according to claim 1 or 2, characterized in that the hollow body (1) is moved linearly and / or rotated. An apparatus for coating a hollow body (1), comprising a distribution device (2) movable into the hollow body (1), and using this distribution device (2) a hollow body to be coated with a coating material ( 1), wherein the device further comprises a rotary drive (4) and a linear drive (3) for the dispensing device (2) and / or the hollow body (1),
An exercise procedure that is repeated until the surface is completely covered and proceeds as follows:
-Moving the dispensing device (2) relatively linearly relative to the hollow body (1);
-For controlling the rotary drive (4) and the linear drive (3) to carry out relative rotation of the dispensing device (2) relative to the hollow body (1) by a defined angle; A device characterized in that a control means (5) is provided.   Device according to claim 4, characterized in that the linear drive is formed as a two-axis or three-axis linear drive.

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