EP1733200A1 - Method and device for negatively counterbalancing an impeller, and method for producing a negatively counterbalanced impeller - Google Patents

Abstract

The invention relates to a device for negatively counterbalancing an impeller (6), said device comprising a grip mechanism (1) provided with a grip drive (2) and a grip (4) for gripping the impeller (6). Said device also comprises a laser device (8) provided with a laser (9), and a positioning unit (10) for adjusting the position of the laser (9) and thus the laser beam (12) produced by the laser (9). The inventive device further comprises a control unit (14) that is embodied in such a way as to control the grip device (1) such that it grips the impeller (6) and positions the same (6) in relation to the laser device (8). Said control unit is also embodied in such a way as to control the positioning unit (10) and the laser (9) such that a pre-determinable contour (16) can be cut out of the impeller (6) by the laser (9). It is also used to control the grip device (1) in such a way as to position the impeller (6) and to release the same (6).

Description

description

Method and device for negative balancing an impeller and method for producing a negatively balanced impeller

The invention relates to a device and a method for the negative balancing of an impeller and a method for producing a negatively balanced impeller. Such impellers are used in particular as radial fan wheels for heating or air conditioning fans in motor vehicles. In order to ensure a high level of comfort in the vehicle, such wheels should be characterized by a low noise level under all operating conditions. The prerequisite for such low noise is also the compensation of the smallest residual imbalance of the impeller. Such impellers are often operated at very high speeds. The imbalances lead to wobbling movements of the impeller in relation to its axis of rotation and thus lead to corresponding noise emissions. The balancing can be done by removing material from the blades of the impeller or is often done by attaching clamps with the appropriate mass. The setting of brackets is relatively time-consuming in the production of the fan wheel and thus increases the cycle times in production. In addition, the individual impeller blades can also be difficult to access for setting the clamps.

To eliminate imbalances in impellers, it is also known to carry out a so-called "negative balancing", in which material is removed from the impeller at certain positions and the imbalance is thus eliminated. With regard to negative balancing, it is known from DE 197 48 309 C2 by means of a punch out material designed as a pistol using a cutting punch. Such a punching tool allows a defined punching out of material from the impellers of an impeller, but the tool must be adapted to the geometry of the wheel and must therefore be converted, for example, for left-hand and right-hand impellers. In addition, it may not be suitable for impellers with a correspondingly small distance between the impeller blades.

The object of the invention is to provide a device for the negative balancing of an impeller and a method for the negative balancing of an impeller which enable precise balancing of the impeller regardless of the geometry of the impeller. Furthermore, the object of the invention is to create a method for producing a negatively balanced impeller, which enables precise balancing of the impeller.

The task is solved by the characteristics of the? independent claims. Advantageous developments of the invention are characterized in the subclaims.

The invention is characterized by a device for negative balancing of an impeller, a corresponding method for operating the device for negative balancing of the impeller and a corresponding method for producing a negatively balanced impeller. The device for negative balancing has a gripping device which has a gripping drive and a gripper which is designed for gripping an impeller. It also has a laser device which has a laser and a positioning unit, which is used to adjust the position of the laser and thus that of the laser. producible laser beam is provided. Furthermore, a control unit is provided which is designed to control the gripping device in the sense of gripping the laurel wheel and positioning the impeller relative to the laser device, for controlling the positioning unit and the laser in such a way that the laser provides a predeterminable contour from the Impeller is cut and to control the G-rip device in the sense of further positioning the impeller and releasing the impeller. The invention thus has the advantage that it can be used for different geometries of the respective impeller, in particular with regard to the alignment of the impeller blades of the laurel wheel. It can thus be used, for example, to manufacture both left-hand drive and right-hand drive wheels.

In addition, it can also be used for negative balancing of impellers regardless of the respective spacing of the impeller blades. In the case of the impellers balanced according to the invention, there is also “very good flow behavior due to the rounded cutting edges created by laser cutting. Furthermore, very fast balancing of the impeller is possible, since several impeller blades can be machined simultaneously by means of the laser beam. In addition, the contour that is cut from the impeller by means of the laser can be varied very easily. In particular, only the control of the positioning unit and the laser must be adapted accordingly. A simple compensation against a "zero unbalance" and thus a distribution of the residual unbalance values close to zero is possible. According to an advantageous embodiment of the invention, the control unit is designed to read in unbalance data for positioning the impeller relative to the laser device. In this way, the imbalance of the impeller can be determined by another device, which may be in another place, and manual input of the imbalance data is not necessary at the same time.

According to a further advantageous embodiment of the invention, a light sensor is provided, by means of which a reference angle position of the gripped impeller can be determined in cooperation with the gripping device. In this way, precise positioning of the laurel wheel relative to the laser device is made possible in a simple manner.

In a further advantageous embodiment of the invention a suction device is provided which is formed ^~ t for sucking material which, by means of the laser of. Impeller was cut. In this way it can easily be ensured that no waste parts “caused by the negative balancing” remain as foreign bodies in the impeller or in a device assigned to the impeller and can lead to faults there.

If the laser is a carbon dioxide laser, it is particularly well suited for negative balancing a plastic wheel -S.

It is also particularly advantageous if the gripping device for positioning the impeller is controlled relative to the laser device, the positioning unit and the laser are controlled in such a way that the laser cuts a "definable contour from the fan wheel , the gripping device for positioning the impeller in another relative position to the laser device is controlled and the positioning unit and the laser are controlled such that the laser cuts a predeterminable further contour from the impeller. For example, the balancing can take place at two axially spaced positions with respect to the axis of the impeller, ie in two unbalance levels. In this way, even at very high speeds of the impeller, a very quiet running can be guaranteed and a so-called dynamic and static imbalance can be compensated. In this context, balancing in the region of the two axial ends of the impeller, that is to say in the unbalance planes running there, is particularly advantageous.

Embodiments of the invention are explained below with reference to the schematic drawings. Show it:

FIG. 1 shows a device for negative balancing an impeller,

2 shows a further view of the device according to FIG. 2,

Figure 3 shows a negatively balanced impeller and

Figure 4 is a Abla f diagram of a program that is processed in a control unit of the device for negative balancing of the impeller.

Elements of the same construction or function are identified with the same reference symbols in all figures.

An impeller 6 can for example be formed as a fan wheel for a bläsevorrichtung Ge, for example, is provided in egg nem motor vehicle for supplying Frischluf ^~ t or for supplying heated air or supplying cooled air. The impeller is placed and pressed onto a drive shaft of a drive of the blower device during the manufacture of the blower device. A balance sorter is then used to determine which imbalances the impeller 6 has. The balance sorter preferably detects in the area which angle, based on the axis of rotation of the impeller 6, contains imbalances and should, for example, be printed out in a mass which is to be removed in this area in order to eliminate the imbalance. In the case of a radial impeller 6, the impeller blades of which are designed to generate a flow in the radial direction to the impeller 6, corresponding first angles Alphal and second angles Alpha2 and corresponding first and second angles are provided at two positions spaced axially with respect to the axis of the impeller Unbalances UW1, UW2 recorded. The first and second angles Alphal, Alpha2 and first and second imbalances UW1, UW2 thus detected are preferably temporarily stored on a workpiece carrier assigned to the blower device. If the first unbalance UW1 and / or the second unbalance UW2 exceeds a predetermined threshold value, the workpiece carrier with the blower device is guided to an unbalance compensation station. The unbalance compensation station has a lifting shape with a lifting device which is designed to convey the blower device with the workpiece carrier to a chamber in which there is a device for negative balancing of the impeller. Alternatively, the workpiece carrier can also remain outside the chamber.

The device for negative balancing of the impeller 6 has a gripping device 1 with a gripping drive 2 and a gripper 4. The gripper 4 is designed for gripping the impeller, preferably on a pin formed centrally in the impeller 6, the impeller hub. The gripping device is also made formed for positioning the impeller relative to the laser device. The gripping drive 2 preferably comprises an electric motor, which acts on the gripper by means of a coupling device. In this way, both the gripper itself can be operated and the gripper can be rotated about its axis.

Furthermore, the device for negative balancing has a laser device 8 with a laser 9 and a positioning unit 10. The laser device is provided for adjusting the position of the laser 9 and thus the laser beam that can be generated by the laser 9. If the impeller 6 is made of plastic, the laser 9 is preferably a carbon dioxide laser. If the impeller is made of metal, the laser is preferably a YAG laser. The positioning unit 10 is preferably designed as a stepper motor and the beam guidance of the laser can be refocussed onto each paddle wheel by means of this. The laser beam generated by the laser 9 is designated by the reference number 12.

Furthermore, a control unit 14 is provided, which is designed to actuate the gripping device 1 in the sense of gripping the impeller 6 and positioning the impeller 6 relative to the laser device 8. The control unit 14 is also designed to actuate the positioning unit 10 and the laser 9 such that a predeterminable contour 16 is cut out of the impeller 6 by the laser.

Furthermore, a reading unit 18 is provided for reading in unbalance data, which are the first and second angles Alphal, Alpha2 and the first and second unbalance UW1, UW2. The reading unit 18 reads in this data and then makes it available to the control unit 14. Furthermore, a light sensor 20 is provided, by means of which a reference angle Alpha_Ref of the gripped impeller 6 can be determined in cooperation with the gripping device. For this purpose, the gripping drive 2 rotates the impeller 6 about its axis until the light sensor 20 delivers a characteristic signal which is generated when the impeller 6 with a reference mark 22 is in alignment with a light beam generated by the light beam of the light sensor 20. The first and second angles Alphal, Alpha2 are related to this reference angle Alpha_Ref. Furthermore, a suction device 24 is also provided, which sucks off material separated by means of the laser and thus ensures that this material, which is also referred to as waste material, does not remain as a foreign body in the region of the fan wheel and leads to malfunctions during later operation of the impeller.

FIG. 2 shows a further view of the device for negative balancing and FIG. 3 shows an impeller which was negatively balanced in the device for negative balancing and thus was at least partially produced in the same.

A program which is executed during the operation of the device for negative balancing of the impeller 6, specifically in the control unit 14 during the operation of the device, is explained below with reference to the flow chart in FIG.

The program is started in a step S1, in which variables are initialized if necessary. In a step S2, the first and second angles Alphal, Alpha2 and the first and second imbalances UW1, UW2 are read.

The reference angle Alpha_Ref is then determined in a step S3.

In a step S5, a control signal CTRL_G for the gripping drive 2 is then determined as a function of the first angle Alphal. The fan wheel is then positioned in a predetermined first axial position, which is, for example, in its area of its one axial end and rotated about its axis in the first angle Alphal. This is done relative to the laser device 8 in such a way that the laser beam 12 that can be generated in the laser 9 can then strike a predetermined area of the fan wheel in the area around the first angle Alphal and in the area of the predetermined first axial position. Then the Grei drive 2 is controlled with the control signal CTRL_G.

A control signal CTRL_L is then generated in a step S7 both for the laser 9 and for its positioning unit 10; these can also be two separate control signals. The control signal CTRL_L for the laser 9 and the positioning unit 10 is generated depending on the first imbalance UWl. The laser and the positioning unit are then activated in accordance with the control signal CTRL_L. The control signal CTRL_L for the laser 9 and the positioning unit 10 can simply be determined in such a way that the required mass is removed from the corresponding impeller blades. The contour 16 can depend on the respective unbalance, in this case the first unbalance UW1, but also on other parameters which, for example, the current Describe the behavior of the air flowing through the impeller 6 during the operation of the impeller 6, in particular turbulence of the air flowing past the contour 16 during the operation of the impeller 6.

The processing is then continued in a step S9, in which the control signal CTRL_G for the gripping drive 2 is determined again, depending on the second angle Alpha2. The gripping drive 2 is then controlled in accordance with the control signal CTRL_G for the gripping drive 2. The impeller is preferably also moved in the axial direction in such a way that the laser beam 12 can act on a region of the impeller which is located at its other axial end.

In another step S11, the control signal CTRL_L for the laser 9 and the positioning unit 10 is determined as a function of the second imbalance UW2 in accordance with step S7 and the laser 9 and the positioning unit 10 are controlled accordingly.

In a subsequent step S13, the control signal CTRL_G for the gripping drive is then determined and controlled in such a way that the impeller 6 is brought into a predeterminable end position and the gripper releases the impeller again. From this end position, the impeller can then again be fed to the balancing sorter, if necessary, and if it is determined that the first and / or second unbalance UW1, UW2 falls below the predetermined threshold value, it may be directed to another station at which the drive of the Blower device is still checked and then the manufacturing ends is. The program is then ended in a step S15.

The device for negative balancing of the impeller is thus characterized in that the unbalance compensation can take place independently of the respective impeller, in particular in the manner in which the impeller blades are designed. Furthermore, there is no set-up effort if impellers 6 with different geometries are to be machined in succession in the device for negative balancing. It has also been shown that the unbalance compensation by means of the device for negative balancing requires on average only a third of the time that is required for positive balancing or manual negative balancing using a punching tool.

Claims

claims 1. Device for negative balancing an impeller with - A gripping device (1) which has a gripping drive (2) and a gripper (4) which is designed for gripping an impeller (6), A laser device (8) which has a laser (9) and a positioning unit (10) which is provided for adjusting the position of the laser (9) and thus of the laser beam (12) which can be generated by the laser (9), - A control unit (14) which is designed - to control the gripping device (1) in the sense of gripping the impeller (6) and positioning the impeller (6) relative to the laser device (8), - To control the positioning unit (10) and the laser (9) such that a predetermined contour (16) is cut from the impeller (6) by the laser (9), and - To control the gripping device (1) in the sense of further positioning of the impeller (6) and releasing the impeller (6). 2. Device according to claim 1, wherein the control unit (14) is designed to read unbalance data for positioning the impeller (6) relative to the laser device (8). 3. Device according to one of the preceding claims, in which a light sensor (20) is provided, by means of which a reference angle (Alpha_Ref) of the gripped impeller (6) can be determined in cooperation with the gripping device (1). 4. Device according to one of the preceding claims, in which a suction device (24) is provided, which is designed for suctioning material which has been cut from the impeller (6) by means of the laser (9). 5. Device according to one of the preceding claims, wherein the laser (9) is a carbon dioxide laser. 6. A method for negative balancing an impeller (6) with a device according to one of the preceding claims, in which - The gripping device (1) for gripping the impeller (6) is controlled, - The gripping device (1) for positioning the impeller (6) is controlled relative to the laser device (8), - The positioning unit (10) and the laser (9) are controlled such that a predetermined contour (16) is cut from the impeller (6) by the laser (9) and - The gripping device (1) in the sense of further positioning of the impeller (6) and releasing the impeller (6) is controlled. 7. The method according to claim 6, in which before further positioning and releasing the impeller (6) - The gripping device (1) for positioning the impeller (6) in another relative position to the laser device (8) is controlled and - The positioning unit (10) and the laser (9) are controlled such that the laser (9) cuts a predeterminable further contour from the impeller (6). 8. The method according to any one of claims 6 or 7 in connection with claim 2, in which imbalance data are read in before the actuation of the positioning unit (10) and the laser (9). 9. The method according to any one of claims 6 to 8 in conjunction with claim 3, in which the reference angle (Alpha_Ref) of the gripped impeller (6) is determined before the positioning unit (10) and the laser (9) are activated. 10. A method for producing an impeller by means of a device according to one of claims 1 to 5, in which - The gripping device (1) for gripping the impeller (6) is controlled, - The gripping device (1) for positioning the impeller (6) is controlled relative to the laser device (8), - The positioning unit (10) and the laser (9) are controlled such that a predetermined contour (16) is cut from the impeller (6) by the laser (9) and - The gripping device (1) in the sense of further positioning of the impeller (6) and releasing the impeller (6) is controlled.