METHOD AND APPARATUS FOR DETERMINING THE ORIENTATION OF ECCENTRIC BUSHINGS

Abstract

A method of replacing eccentric bushings installed on the gangheads of machine tools for adjusting a machining operation. The machine tools, which are used to machine or otherwise process parts, utilize the eccentric bushings for applying fine adjustments to the machining by adjusting the location of the machining operation in a plane using the orientation and amount of eccentricity of the bushing. Also the apparatuses provided for supporting this method.

Description

BACKGROUND

This application relates generally to a method of replacing bushings on a machine, and more specifically, this application relates to the replacement of eccentric bushings on the gangheads of machine tools that utilize the eccentric bushings for applying fine adjustments to the tools of the machine tool for processing parts or other products.

Eccentric bushings are sometimes utilized inside CNC machine tools, such as in their docking posts, in situations where the tools cannot be finely adjusted in a Cartesian two-dimensional manner (i.e., adjusted in a vertical-y and horizontal-x direction for a tool machining in the x, y plane), or in situations where additional adjustments to the machining operation are desirable. However, over time, the bushings can wear or the machine tools otherwise become out-of-adjustment, in which case adjustments to the machining operation are desirable. Such adjustments may be done by replacing the eccentric bushings, in some circumstances.

Conventional approaches for replacing eccentric bushings have involved complex manual calculations by hand that can take a long time to accomplish and thus are inefficient, and because of the complex manual calculations, errors can be introduced.

Hence, a new approach to adjusting or replacing such eccentric bushings that overcomes one or more of these problems is desirable.

SUMMARY

Provided are a plurality of example embodiments, including, but not limited to, a method of installing a bushing in a device, comprising the steps of: determining a desired effect of a bushing on the device; automatically determining, using a computer executing a software application, a desired parameter of the bushing based on the desired effect; automatically determining, using the computer executing the software application, a desired installation orientation of the bushing based on the desired effect; and installing the bushing in the device according to the installation orientation, wherein the device substantially exhibits the desired effect.

Also provided is a method of replacing an eccentric bushing in a device, comprising the steps of: determining an installation orientation of a current bushing installed in the device; removing the current bushing from the device; determining at least one characteristic of the current bushing; calculating at least one desired characteristic of a replacement bushing; selecting the replacement bushing based on at least one of the at least one desired characteristic of the replacement bushing; determining an installation orientation of the replacement bushing at least partially based on at least one characteristic of the current bushing; and installing the replacement bushing in the device according to the determined installation orientation of the replacement bushing.

Still further provided is a method of replacing an eccentric bushing in a device, comprising the steps of: determining an installation orientation of a current bushing installed in the device; providing on mark on the device indicating the current installation orientation; providing a mark on the current bushing indicating the current installation orientation; removing the current bushing from the device; determining a value and location of a high point of eccentricity of the current bushing; providing a mark on the current bushing indicating the position of the high point of eccentricity of the current bushing; using a position indicating device for determining a relative orientation distance between the mark indicating the high point of eccentricity of the current bushing relative to the mark indicating the current installation orientation of the current bushing; calculating, using a computer program executing on a computer, a position and desired value of a high point of eccentricity of a replacement bushing based on criteria including: the value of the high point of eccentricity of the current bushing, the relative orientation distance of the current bushing, and desired adjustments to be made to the device; providing the replacement bushing that best matches the desired value of the high point of eccentricity of the replacement bushing; locating and providing a mark of the position of the high point of eccentricity of the replacement bushing; using the position indicating device for determining an installation orientation for the replacement bushing based on the mark of the position of the high point of eccentricity of the replacement bushing and also based on the calculated position of the high point of eccentricity; providing a mark on the replacement bushing indicating the installation orientation; and installing the replacement bushing in the device according to the mark on the replacement bushing indicating the installation orientation and according to the mark on the device indicating the current installation orientation, whereby the desired adjustments are substantially made to the device.

Also provided are additional example embodiments, some, but not all of which, are described hereinbelow in more detail.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the example embodiments described herein will become apparent to those skilled in the art to which this disclosure relates upon reading the following description, with reference to the accompanying drawings, in which:

FIG. 1 is a front view of an example ganghead that has a docking post utilizing an eccentric bushing;

FIG. 2 is a close-up view of the eccentric bushing installed in the example ganghead of FIG. 1 with the docking post removed;

FIG. 3 is a view of a level insert installed in eccentric bushing of FIG. 2;

FIG. 4 is a view of the eccentric bushing of FIG. 2 marked with a 12:00 position;

FIG. 5 is a view of the eccentric bushing of FIG. 2 being measured by a caliper with its highpoint marked;

FIG. 6 is a view of an example position indicating device being used with the bushing of FIG. 5 to determine the position of its highpoint;

FIG. 7 is a screen shot of an example user interface for an example application for determining a desired bushing eccentricity;

FIG. 8 is the screen shot of FIG. 7 showing example data and calculations;

FIG. 9 is a view of a replacement eccentric bushing being measured by the caliper with its highpoint marked;

FIG. 10 is a view of the position indicating device being used with the replacement bushing of FIG. 9 to determine its 12:00 position; and

FIG. 11 is a close-up view of the replacement bushing installed in the ganghead to replace the eccentric bushing shown in FIG. 2.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

FIG. 1 shows an example ganghead 1 of a CNC machine tool, where tool holders 3 and 5 are used to hold tools (such as drill bits or ream bits, for example, not shown) to machine a part being carried by a pallet, for example. Docking post 10 is provided to match the pallet (not shown) that is a carrier of the part to be machined, with the part being held by the pallet in a position to be machined. More than one such docking post may be provided on some gangheads. Generally, the machine tool can be adjusted in the x-y plane (or x-z or y-z plane) by providing eccentric bushings in the docking post. The eccentric bushings operate to finely move the position of the where tool holders 3, 5 (and thereby move the position of the tools) with respect to the part to be machined (when the pallet holding the part is mated to the ganghead) in a desired direction in the x-y plane, to perform one or more machine operations on the part. Hence, the location of machine operations on the part in the desired plane can be finely controlled through the use of eccentric bushing(s) in the docking post(s) 10, even when the CNC tool cannot be programmed to do so.

FIG. 2 shows a close-up of the ganghead 1 with the docking post 10 removed from its mount 11. Bushing 100 is provided in the docking post mount 11 at hole 13. Generally, as discussed above, it is desirable that the eccentric bushing 100 be eccentric in shape (i.e., not be perfectly round, but have a high point that is out-of-round) to provide a desired fine adjustment of the tooling operation that the tools of the ganghead 1 perform on the part, with respect to the x-y plane. However, the eccentric bushing 100 may go out of adjustment, or over time additional adjustment of the machining of the part may be desired (such as due to changes in the machine tool and/or its components over time), in which case it may be desirable to replace the bushing 100 (and potentially other bushings as well) to obtain the desired fine adjustment of the machining process.

In order to replace the eccentric bushing 100, it is desirable to determine its current position and amount of eccentricity, and to determine how best to install a new eccentric bushing to regain the desired adjustment of the ganghead. In order to do so, the current position of the bushing must be determined. However, the ganghead itself should be leveled prior to this operation.

Referring to FIG. 3, a level 111 mounted on a level insert 110 is used to determine an orientation of the ganghead, in this case the 12:00 position of the mount, by installing the level insert 110 in the center of the bushing 100, which is covered by the level insert and thus not seen in FIG. 3. Using an indication 112 located on the level insert 110 which indicates the 12:00 position, a mark 113 is provided on the mount 11 using paint or a marker at the 12:00 position, so that the mark 113 matches the location of the indication 112. Preferably, the mark 113 should be in color chosen to indicate its purpose, and in this example case, it is chosen to be a red mark to signify that it represents the 12:00 position. This mark 113 now provides an orientation baseline for the replacement process.

Referring to FIG. 4, the level insert 110 with the level 111 is removed, and the bushing 100 is marked at the 12:00 position 115 to match the 12:00 position of the mark 113 previously provided on the mount 11. It is preferable that this mark be done using the same color as the corresponding mark on the mount 11, and thus in this example it is marked in red to indicate that it represents the 12:00 position. The bushing 100 is thereby marked to show its installation orientation in the ganghead.

The eccentric bushing 100 is then removed from the mount 11 to be measured and replaced. In some cases, the removal of this bushing 100 may require the use of a tool, as the bushing may be snug in its fit.

FIG. 5 shows the eccentric bushing 100 being measured using a caliper 30. The bushing 100 is rotated in the caliper as its thickness is monitored in order to examine its amount of eccentricity by finding the value and location of its high point (in this case it is found to have an eccentric high point of 0.060 mm). Mark 115 can be seen on the bushing, and a new mark 120 is put on the bushing at the high point as found by using the caliper 30. This mark 120 should be in a different color than that used for mark 115 to properly differentiate the mark as indicating the high point on the bushing. In this example, the mark 120 is done in yellow.

As shown in FIG. 6, to determine the location of the high point 120 with respect to the 12:00 position (and thus determine the relative distance between them), the bushing 100 is then placed in a position indicating device 60 which has a dial 61 that, in this example, is divided into indications of 12 hours and fractions thereof. Of course, other types of indications not based on time (clocks) could also be used. The red 12:00 mark 115 is placed at the 12:00 position on the device 60 dial 61, and the position of the yellow mark 120 can be read on the dial 61. In this example, the mark is shown at the 2:30 position. Thus is it determined where the high point of the eccentric bushing 100 is located with respect to the 12:00 position, giving a relative position between them (in this example, the distance is measured in “hours”).

Now it is desired to determine what the desired dimensions of the replacement bushing should be. An example software application running on a computer is used for determining the desired replacement bushing dimensions is utilized to determine the desired parameters of the replacement bushing. Any commercially available computer can be used, such as a personal computer running MS Windows, or a server, for example, provided with a GUI interface for user interaction. Portable computers could also be utilized. The software application can be developed using any commercially available programming language, such as C or Java, or any other programming language, and may be web-based. The software application is programmed such that, based on the setup of the machine tool, ganghead, the tool holders, and the location of the part to be machined, the desired parameters (characteristics) of replacement eccentric bushing, e.g., their high-point value and installation orientation, can be determined based on desired impacts to the machining operation, and based on the parameters of the current bushing, that are input to the software application by the user.

FIG. 7 shows a screen shot of an example user interface 50 for an example software application that can be used for the example embodiment. Various fields will be populated at various stages of the process. Instructions 51 describing proper use of the software application are provided to the user via this user interface 50. This example software application can be used for various different processes, so the user chooses the current desired process using a drop down menu 59 (choosing from options such as “docking post” or “individual spindle”, for example).

The user interface 50 has a current part location field 54 for entering a desired adjustment of the ganghead tools (which will result in machining the part at the desired location, as compared to the previous setup using the original eccentric bushing which was not at the desired location); a CMM reference sheet field 53 where data can be directly entered, if desired; a time chart 52 indicating the inner diameter of the type of bushing being replaced; a current bushing information field 55 for entering information about the current bushing 100 that is being replaced; a current bushing ganghead effect field 56 for showing the effect the current bushing has on the ganghead, a replacement bushing ganghead effect field 57 for showing the effect that the desired replacement bushing will have on the ganghead placement with respect to machining the part; and a replacement bushing desired dimensions field 58 for indicating the desired parameters of the replacement bushing.

Referring now to FIG. 8, the user enters the amount and direction that the current part is away from nominal (an error amount) by action of the current bushing by entering the data into the current part location field 54′. For this example, the variance from desired location is 0.035 mm vertical and 0.040 mm horizontal (of course, instead of entering an error amount, absolute desired location information could be used, or some other indication of the desired changes, in different example applications). The user also enters the information determined about the current bushing 100 in the current bushing information field 55′. This includes the high point measurement and its location. For this example, the high point of the current bushing was found to be 0.060 mm at the 4:30 position.

The software application then determines a desired size and eccentricity angle of the replacement bushing displayed in the replacement bushing desired dimensions field 58′. In this case, the software application determines that a replacement bushing having a 0.113 mm high point being used at an installation orientation of 4:26 is desirable. The software application takes into account the characteristics of the machine tool (the location of the tools and the part being machined, and the location of the bushings and their impact on the machining process), in order to perform these calculations. Thus, the software application must be adapted to include parameters for the particular machine tool being modified.

A replacement bushing 200 is chosen, such as by trial and error in measuring potentially acceptable bushings, or by selecting from pre-measured, previously sorted bushings. It is desired that a replacement bushing be selected that is as close as possible to the desired dimensions determined by the application (i.e., an eccentric high point of 0.113 mm). The thus selected replacement bushing is placed in the caliper 30 as shown in FIG. 9 and the high point of the bushing is determined using the caliper, with the high point being marked in yellow using indication 220. Then, the replacement bushing 200 is placed in the position indicating device 60 as shown in FIG. 10 with the yellow high point mark 220 placed at the position determined by the software application as displayed on the user interface 50, in this case at approximately the 4:26 position as shown in the figure. Then, the 12:00 position 215 is marked in red on the new bushing 200 for indicating the desired installation orientation of the replacement bushing 200.

If desired, the software application can be adapted to show the impact of the actual values of the replacement eccentric bushing on the machine tool, if those values vary from the desired values.

Properly marked, the replacement bushing 200 is now ready to be installed on the mount 11 of the ganghead 1 as shown in FIG. 11, with the bushing installed with the 12:00 mark 215 matching the 12:00 mark 113 at the hole 13 of the mount 11. This results in the replacement bushing 200 being installed in the desired orientation. The docking post 10 can then be installed on the mount 11 to return the ganghead 1 to the state found in FIG. 1, but with the machine tool now better able to position the machining tools at the desired machining locations.

The system and procedures identified herein can also be used for other applications where the positioning of a part based on some criteria must be determined and/or adjusted, beyond use in machining operations, but anywhere fine adjustments or replacement of finely differentiated parts is desirable.

Many other example embodiments can be provided through various combinations of the above described features. Although the embodiments described hereinabove use specific examples and alternatives, it will be understood by those skilled in the art that various additional alternatives may be used and equivalents may be substituted for elements and/or steps described herein, without necessarily deviating from the intended scope of the application. Modifications may be necessary to adapt the embodiments to a particular situation or to particular needs without departing from the intended scope of the application. It is intended that the application not be limited to the particular example implementations and example embodiments described herein, but that the claims be given their broadest reasonable interpretation to cover all novel and non-obvious embodiments, literal or equivalent, disclosed or not, covered thereby.

Claims

1. A method of installing a bushing in a device, comprising the steps of:

determining a desired effect of a bushing on the device;

automatically determining, using a computer executing a software application, a desired parameter of the bushing based on the desired effect;

automatically determining, using the computer executing the software application, a desired installation orientation of the bushing based on the desired effect; and

installing the bushing in the device according to the installation orientation, wherein the device substantially exhibits the desired effect.

2. The method of claim 1, further comprising the steps of:

determining a value of a high point of eccentricity of a previous bushing installed in the device; and

removing the previous bushing from the device, wherein

both of the steps of automatically determining are also based on the determined value of the high point of eccentricity of the previous bushing.

3. The method of claim 2, further comprising the step of determining an installation orientation and a position of the high point of eccentricity of the previous bushing, wherein both said automatically determining steps are also based on the determined installation orientation and position of the high point of eccentricity of the previous bushing.

4. The method of claim 3, wherein said device is a device for machining a part, and wherein the desired effect is based on a desired location for the device performing machining on the part.

5. The method of claim 4, wherein the desired effect is also based on a location of the device performing machining on the part with the previous bushing installed.

6. The method of claim 4, wherein the desired parameter includes a value of a high point of eccentricity of the bushing.

7. The method of claim 1, wherein the desired parameter includes a value of a high point of eccentricity of the bushing.

8. The method of claim 1, wherein said device is a device for machining a part, and wherein the desired effect is based on a desired location for the device performing machining on the part.

9. The method of claim 1, further comprising the step of, prior to installing the bushing in the device, marking the bushing to indicate the desired installation orientation of the bushing.

10. The method of claim 1, further comprising the step of selecting the bushing from a plurality of bushings based on the desired parameter.

11. A method of replacing an eccentric bushing in a device, comprising the steps of:

determining an installation orientation of a current bushing installed in the device;

removing the current bushing from the device;

determining at least one characteristic of the current bushing;

calculating at least one desired characteristic of a replacement bushing;

selecting the replacement bushing based on the at least one desired characteristic of the replacement bushing;

determining an installation orientation of the replacement bushing at least partially based on the at least one characteristic of the current bushing; and

installing the replacement bushing in the device according to the determined installation orientation of the replacement bushing.

12. The method of claim 11, wherein said step of determining the installation orientation of the current bushing includes the step of using a level to locate an orientation position on the device.

13. The method of claim 12, wherein said step of determining the installation orientation of the current bushing also includes the step of providing an installation mark on the current bushing indicating its installation orientation with respect to the located orientation position on the device.

14. The method of claim 13, wherein said step of determining at least one characteristic of the current bushing includes the steps of:

determining a position of a high point of eccentricity of the current bushing; and

using a position indicating device to measure a distance between the position of the high point of eccentricity of the current bushing relative to the installation mark on the current bushing, wherein

said step of determining the installation orientation of the replacement bushing is at least partially based on the measured distance.

15. The method of claim 14, wherein said step of determining an installation orientation of the replacement bushing includes the steps of:

determining a position of a high point of eccentricity of the replacement bushing; and

providing a mark indicating the position of the high point of eccentricity on the replacement bushing.

16. The method of claim 15, further comprising the step of using the position indicating device to locate an installation orientation of the replacement bushing relative to the mark indicating the position of the high point of eccentricity on the replacement bushing.

17. The method of claim 16, further comprising the step of providing a mark indicating the installation orientation of the replacement bushing, wherein said mark indicating the installation orientation is used with the located orientation position on the device for installing the replacement bushing in the device.

18. The method of claim 16, wherein a desired value for the high point of eccentricity on the replacement bushing and the location of the installation orientation of the replacement bushing are determined based on a data output from a computer program executing on a computer, wherein said data output determined is based on a desired modification of the device and is also based on the installation orientation and the high point of eccentricity of the current bushing.

19. The method of claim 11, wherein the step of calculating at least one characteristic of the replacement bushing is automatically accomplished using a computer program executing on a computer, such that the at least one characteristic is based on a desired modification of the device entered into a user interface to the program.

20. A method of replacing an eccentric bushing in a device, comprising the steps of:

determining an installation orientation of a current bushing installed in the device;

providing a mark on the device indicating the current installation orientation;

providing a mark on the current bushing indicating the current installation orientation;

removing the current bushing from the device;

determining a value and location of a high point of eccentricity of the current bushing;

providing a mark on the current bushing indicating the location of the high point of eccentricity of the current bushing;

using a position indicating device for determining a relative orientation distance between the mark indicating the high point of eccentricity of the current bushing relative to the mark indicating the current installation orientation of the current bushing;

calculating, using a computer program executing on a computer, a position and desired value of a high point of eccentricity of a replacement bushing based on criteria including: the value of the high point of eccentricity of the current bushing, the relative orientation distance of the current bushing, and desired adjustments to be made to the device;

providing the replacement bushing that best matches the calculated desired value of the high point of eccentricity of the replacement bushing;

locating and providing a mark of a location of the high point of eccentricity of the replacement bushing;

using the position indicating device for determining an installation orientation for the replacement bushing based on the mark of the location of the high point of eccentricity of the replacement bushing and also based on the calculated position of the high point of eccentricity;

providing a mark on the replacement bushing indicating the installation orientation; and

installing the replacement bushing in the device according to the mark on the replacement bushing indicating the installation orientation and according to the mark on the device indicating the current installation orientation, whereby

the desired adjustments are substantially made to the device.