METHOD FOR SUPPLYING CRYOGENIC FLUID TO A MACHINING MACHINE

Abstract

A method for machining workpieces, having a cryogenic fluid intake in a machining zone, including locating a valve on the line connecting a fluid source to a machining tool in the machining zone, the valve self-regulates the degree of opening according to the pressure required downstream thereof, the valve is located inside a cold box for implementing the cryogenic fluid and provides a fixed and adjustable pressure, and a fixed adjustable flow, to the machining tool, irrespective of the tool that is used, and the number of orifices and the diameter of the fluid ejection orifices in the tool.

Claims

1-5. (canceled)

6. A method for machining workpieces, comprising a cryogenic fluid intake in a machining zone, comprising, locating a valve on the line connecting a fluid source to a machining tool in the machining zone, the valve self-regulates the degree of opening according to the pressure required downstream thereof, the valve is located inside a cold box for implementing the cryogenic fluid and provides a fixed and adjustable pressure, and a fixed adjustable flow, to the machining tool, irrespective of the tool that is used, and the number of orifices and the diameter of the fluid ejection orifices in the tool.

7. The method as claimed in claim 6, wherein, upon start-up, and between two machining operations resulting in a machining tool change, and in the disconnection and reconnection of tools at the end of a spindle, gas is purged from the line using nitrogen gas, between the cold box and the machining tool, from the cold box to the end of the spindle initially, then from the cold box to the machining tool, with the supplied gas allowing the tool holder to be heated and thus assist the disconnection.

8. The method as claimed in claim 7, wherein the gas used for purging is preheated.

9. The method as claimed in claim 6, wherein the temperature of the delivered fluid is measured just before it enters the machining zone, and the flow that is used is selected according to this fluid temperature measurement.

10. The method as claimed in claim 9, wherein, when the upstream fluid source has been recently filled, with the fluid then being in a sub-cooled state, then the pressure supplied by said valve is adjusted in order to reduce the supplied flow, whilst keeping the same energy available.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0044] For a further understanding of the nature and objects for the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawing, in which like elements are given the same or analogous reference numbers and wherein:

[0045] FIG. 1 provides a partial schematic view of an installation suitable for implementing the invention.

NOMENCLATURE OF FIG. 1

[0046] 1: the machining center;

[0047] 2: the command cabinet for the machining center;

[0048] 3: spindle;

[0049] 4: tool post or tool holder;

[0050] 5: tool;

[0051] 6: workpiece to be machined;

[0052] 7: safety sensors;

[0053] 10: installation suitable for implementing the invention;

[0054] 11: implementation equipment/cold box (comprising the control valve);

[0055] 12: control/command device of the invention;

[0056] 13: hose;

[0057] 14: safety sensors.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0058] The previous approach of document EP-2986887 (in the name of the Applicant) is known, which approach was different.

[0059] Indeed, if the present invention relates to controlling the pressure delivered to the machining station, with this being according to a “program” implemented in this station, i.e. for all and each tool condition that is implemented, number of orifices, diameter of these orifices, etc., the procedure according to these prior works focused on supplying a plurality of machining stations in parallel, with sub-cooled liquid, at a fixed pressure at each station, and to this end immersed cryogen in a cryogenic bath, before it reached the machining station.

[0060] It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above.