VRP 500旋转刀刀片 说明书

VRP 500 ROTARY KNIFE PROFILER APPLICATION SPECIFICATION
Overview
The custom machine (Figure 1) consists of a web feed rotary knife controlled by an MTS Automation control system. The web is transported by pull rollers driven by a variable speed motor. The pull rollers act as the reference axis for the control system. The rotary knife accelerates and decelerates as the reference accelerates and decelerates. The control system consists of a VRP 500 digital servo controller with custom firmware to provide for the control of a single axis. The servo axis operates the rotary knife in ratio mode to the web. The knife makes a cut at relative speed (overspeed) to the web. After the knife has cleared the web it rotates around in time for the next cut. After an operator-selected number of cuts (COUNT) have been made Output 1 will come on and stay on for 250 ms. During operation the operator can make incremental changes to the part length (trim) and COUNT. The machine designer specifies machine parameters and enters them into the VRP 500 via a custom SETUP [MACHINE] screen. The operator enters product parameters via a new PRODUCT mode. After all the parameters are entered, profile 0 of the VRP 500 can be calculated for controlling the knife by pressing the CALC function key.
The machine designer enters the following machine parameters into the VRP 500, while the RUN line is off, through the custom SETUP [MACHINE] screen:
• maximum knife speed in scaled units per second • maximum knife acceleration in scaled units per second per second • knife radius in scaled units • maximum part length in scaled units • minimum part length in scaled units • maximum cycle rate in parts per minute • maximum web speed in scaled units per second • percent of knife cycle at overspeed • maximum trim in scaled units • trim step size in scaled units • knife offset in scaled units • reference acceleration increment in milliseconds • number of knives per revolution of cutter head
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Motion Profiles The motion profile has the following profile segments: a cutting segment, a non-cutting constant velocity (relative to the reference) segment, and the transitional segments between the cutting and non-cutting segments. The knife always travels one cycle per part. (This means that the number of knives per revolution is identical to the number of cycles per revolution.) The reference travels the part length ± trim units per part. The cutting segment is defined by the product parameter, overspeed (cutting speed), machine parameter, and percent of knife cycle at overspeed. The noncutting constant velocity portion is the segment that is altered by the trim adjustment. The transitional segments are constant acceleration segments (relative to the reference). The acceleration used to make these transitions is the maximum acceleration of the machine when the web is running at maximum web speed. See Figure 2 below.
VRP 500
Rotary Knife Profiler Application Specification
1000 455233-95G ©MTS Systems Corporation 2000
2121 South Bridge Street New Ulm, MN 56073 Telephone: 507-354-1616 Fax: 507-354-1611
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Hardware Description
The control unit consists of a VRP 500 with custom firmware for calculation of profiles and a COUNT output. Programmable limit switch 1 is designated as the COUNT output.
The machine reference is provided by an encoder (absolute or incremental) driven by the pull rollers. It is necessary that this signal provides an accurate and constant representation of material speed.
Count Output
VRP 500
Follower A
Command
Reference
Enable
Master Encoder
E
E M
Rotary Knife
Web
Pull Rollers
Figure 1
Elevator
2
Description of Operation
Profile Calculation
Cutting Period
Time
1 Rev
Reference Position
Figure 2
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Home Position The home position of the follower is automatically calculated and displayed in the SETUP [FOLLOWER] menu. This position is defined as the point in the follower cycle where the knife is in the cut position. Once calculated, this parameter should not be changed (if it is changed, the cut will not be positioned correctly in the cycle). The knife offset position must be entered to compensate for the distance between the knife cut position and the follower home sensor position. If the home sensor is before the cut, this offset should be a negative value. If the home sensor is after the cut, this offset should be a positive value. Once set correctly, any changes in product or profile will automatically be calculated to ensure that the knif the profile.
The operator enters the following product parameters into the VRP 500, while the RUN line is off, through the custom PRODUCT mode:
• part length in scaled units • overspeed as a percent of web speed • cycle rate in parts per minute • COUNT in units.
After all the parameters (product and machine) have been entered, the operator presses the CALC function key; profile 0 is calculated, the home position is calculated, and the COUNT register is reset to zero. The CALC function is active from both the PRODUCT screen and the SETUP [MACHINE] screen. If there is no solution for the parameters that have been entered, an error message is displayed; DATA ERROR n. Appendix A describes the error messages.