System and method for state monitoring of linear drives of stretching and/or blow moulding machines

2:

• The linear drive according to claim 1, wherein the force sensor is a detector for current consumption necessary for movement of stretching rod.

3:

• The linear drive according to claim 1, wherein the data for the desired force absorption of the linear drive during operation are calculated from parameters selected from a group consisting of a weight force of the moving parts, an inertial force of the moving parts depending upon an underlying movement profile, a pressure prevailing in the container or the preform, pneumatically effective surfaces of the system and a frictional force of the stretching unit.

4:

• The linear drive according to claim 1, wherein the storage device comprises a plurality of data sets for the desired force absorption of the linear drive for different reshapings of preforms into containers.

6:

• The method according to claim 5, wherein the force sensor detects current consumption necessary for movement of a stretching rod.

7:

• The method according to claim 5, wherein the data for a desired force absorption of the linear drive during operation are calculated from parameters which are selected from a group consisting of a weight force of the moving parts, an inertial force of the moving parts depending upon an underlying movement profile, a pressure prevailing in the container or the preform, pneumatically effective surfaces of the system and a frictional force of the stretching unit.

8:

• The method according to claim 7, wherein from the parameters first of all a model is calculated which includes a variable for the frictional force on the stretching unit and only in a subsequent optimisation process are simulations of the desired force absorption of the linear drive carried out by variation of values for the frictional force simulation until a sufficiently good approximation between the simulation of the desired force absorption and the actual force absorption of the linear drive is achieved.

9:

• The method according to claim 5, wherein a time range of the process which is particularly suitable for identification of the friction coefficient is selected for comparison of the actual force absorption with the desired force absorption.

10:

• The method according to claim 5, wherein on the basis of the comparison of the actual force absorption with the desired force absorption a required maintenance cycle for the cleaning of the stretching unit is determined.

11:

• The method according to claim 6, wherein the data for a desired force absorption of the linear drive during operation are calculated from parameters which are selected from a group consisting of a weight force of the moving parts, an inertial force of the moving parts depending upon an underlying movement profile, a pressure prevailing in the container or the preform, pneumatically effective surfaces of the system and a frictional force of the stretching unit.

12:

• The method according to claim 11, wherein from the parameters first of all a model is calculated which includes a variable for the frictional force on the stretching unit and only in a subsequent optimisation process are simulations of the desired force absorption of the linear drive carried out by variation of values for the frictional force simulation until a sufficiently good approximation between the simulation of the desired force absorption and the actual force absorption of the linear drive is achieved.

13:

• The method according to claim 6, wherein a time range of the process which is particularly suitable for identification of the friction coefficient is selected for comparison of the actual force absorption with the desired force absorption.

14:

• The method according to claim 6, wherein on the basis of the comparison of the actual force absorption with the desired force absorption a required maintenance cycle for the cleaning of the stretching unit is determined.

15:

• The method according to claim 7, wherein a time range of the process which is particularly suitable for identification of the friction coefficient is selected for comparison of the actual force absorption with the desired force absorption.

16:

• The method according to claim 7, wherein on the basis of the comparison of the actual force absorption with the desired force absorption a required maintenance cycle for the cleaning of the stretching unit is determined.

17:

• The method according to claim 8, wherein a time range of the process which is particularly suitable for identification of the friction coefficient is selected for comparison of the actual force absorption with the desired force absorption.

18:

• The method according to claim 8, wherein on the basis of the comparison of the actual force absorption with the desired force absorption a required maintenance cycle for the cleaning of the stretching unit is determined.

19:

• The method according to claim 9, wherein on the basis of the comparison of the actual force absorption with the desired force absorption a required maintenance cycle for the cleaning of the stretching unit is determined.