Patent Application
20100164424
1. Technical Field
The present disclosure relates to compensation systems and methods, and particularly to a tool compensation system and a tool compensation method for a computer numerical control (CNC) machine.
2. Description of the Related Art
A tool is a significant component of a CNC machine used for machining metal articles. Generally, tool wear may occur during the machining processes, which may result in size variations of the articles. Therefore, a single-spindle CNC machine employs a tool compensation system for compensating abrasion of a single tool mounted on the single-spindle.
A multi-spindle CNC machine greatly enhances production capacity. However, abrasion of the many tools mounted on the multi-spindle CNC machine may not be consistent. Thus, the tool compensation system may affect machining precision of the multi-spindle CNC machine.
Referring to
Generally, the tool compensation system 100 is applied in a computer numerical control (CNC) machine, such as a multi-spindle CNC machine. The four tools 12 may be fixed to four spindles 10 of the multi-spindle CNC machine for machining four articles 40 on the four compensation apparatuses 30 respectively. In one embodiment, the four tools 12 can be four milling cutters, the four articles 40 can be objects made of metal, and the rangefinder 50 can be a laser rangefinder. In other embodiments, the number of the spindles 10, the tools 12, and the compensation apparatuses 30 can be varied according to actual need.
In one embodiment, each of the compensation apparatuses 30 includes a support 31 fixed on the working platform 20, an actuator 32 mounted on the support 31 and connected to the control system 60, a transmission element 33 connected to the actuator 32, a regulator 35 mounted to the transmission element 33, and two guiding poles 36 connected to the support 31 and running through the regulator 35. The regulator 35 can move along the two guiding poles 36, under actuation of the actuator 32 and the transmission element 33. In one embodiment, the actuator 32 can be a servomotor.
In use, the rangefinder 50 measures an actual length L1 of a tool 12, and transmits the actual length L1 to the control system 60, before the article 40 under the tool 12 is machined. The control system 60 compares the actual length L1 with a previous length L2 of the tool 12 measured by the rangefinder 50 before the last machining circle run and stored in the control system 60, to obtain a compensation value L=L2−L1. The control system 60 replaces the previous length L2 with the actual length L1 to update the length of the tool 12 stored in the control system 60. An actuator 32 of the compensation apparatus 30 actuates a transmission element 33 to move a distance equal to the compensation value L, after receiving a control instruction from the control system 60. The transmission element 33 actuates a regulator 35 to move towards the tool 12 to compensate for abrasion of the tool 12.
For example, when the actual length L1 measured by the rangefinder 50 is about 4.999 cm, and the previous length L2 stored in the control system 60 is about 5.000 cm, then the compensation value L calculated by the control system 60 is about 0.001 cm, that is L=L2−L1=5.000 cm−4.999 cm=0.001 cm. The control system 60 controls the actuator 32 to work according to the compensation value L. The actuator 32 actuates the transmission element 33 to move a distance equal to 0.001 cm, and the transmission element 33 drives the regulator 35 to move towards the tool 12 to compensate for abrasion of the tool 12. The article 40 therefore can be put on the regulator 35 to be machined by the tool 12.
Likewise, abrasion of the other tools 12 can be compensated by the corresponding compensation apparatuses 30 under the control of the control system 60 using the same process as mentioned above. Even though abrasion of the tools 12 may be different for different tools, each tool is easily and uniquely compensated by the corresponding compensation apparatuses 30 before every machining circle run, and the multi-spindle CNC machine can machine the articles 40 with a high machining precision.
Referring to
In block S1, the rangefinder 50 measures an actual length L1 of a tool 12 and transmits the actual length L1 to the control system 60.
In block S2, the control system 60 compares the actual length L1 with a previous length L2 of the tool 12 measured by the rangefinder 50 before the last machining circle run and stored in the control system 60, to obtain a compensation value L=L2−L1. Then, the control system 60 replaces the previous length L2 with the actual length L1 to update the length of the tool 12 stored in the control system 60, and outputs a control instruction to a compensation apparatus 30 according to the compensation value L.
In block S3, an actuator 32 of the compensation apparatus 30 actuates a transmission element 33 to move a distance equal to the compensation value L, after receiving the control instruction from the control system 60. A transmission element 33 of the compensation apparatus 30 actuates a regulator 35 to move towards the tool 12 to compensate for abrasion of the tool 12.
It is to be understood, however, that even though numerous characteristics and advantages of the present disclosure have been set forth in the foregoing description, together with details of the structure and function of the disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200810306601.X | Dec 2008 | CN | national |
