Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B31/00—Machines or devices designed for polishing or abrading surfaces on work by means of tumbling apparatus or other apparatus in which the work and/or the abrasive material is loose; Accessories therefor
  • B24B31/10—Machines or devices designed for polishing or abrading surfaces on work by means of tumbling apparatus or other apparatus in which the work and/or the abrasive material is loose; Accessories therefor involving other means for tumbling of work
  • B24B31/116—Machines or devices designed for polishing or abrading surfaces on work by means of tumbling apparatus or other apparatus in which the work and/or the abrasive material is loose; Accessories therefor involving other means for tumbling of work using plastically deformable grinding compound, moved relatively to the workpiece under the influence of pressure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
  • B24C3/00—Abrasive blasting machines or devices; Plants
  • B24C3/32—Abrasive blasting machines or devices; Plants designed for abrasive blasting of particular work, e.g. the internal surfaces of cylinder blocks
  • B24C3/325—Abrasive blasting machines or devices; Plants designed for abrasive blasting of particular work, e.g. the internal surfaces of cylinder blocks for internal surfaces, e.g. of tubes
  • B24C3/327—Abrasive blasting machines or devices; Plants designed for abrasive blasting of particular work, e.g. the internal surfaces of cylinder blocks for internal surfaces, e.g. of tubes by an axially-moving flow of abrasive particles without passing a blast gun, impeller or the like along the internal surface

Definitions

• the invention is based on a method for the hydroerosive rounding of holes or holes in components, in particular of spray holes in nozzle bodies of fuel injection valves.
• FIG. 1 illustrates this rounding process according to the prior art using the example of a nozzle body 10 shown in longitudinal section.
• an obstacle body 12 is inserted, of which in FIG. 1, a with respect to the longitudinal axis 17 of the nozzle body 10 right-side cutout is shown.
• the interior 1 1 of the nozzle body 10 delimiting wall 13 is penetrated by a bore 14.
• a fluid medium which has highly abrasive grinding particles, via an inlet channel or flow channel 16 into the interior 1 1 under a certain pressure p- ⁇ initiated.
• the pressurized fluid medium flows around the obstacle body 12 in the interior space 11 of the nozzle body 10, and finally passes outwardly through the bore 14 to be machined.
• the inlet edge 15 of the bore 14 lying on the inlet side of the bore 14 is rounded.
• a disadvantage of this prior art is that the removal of material during the rounding process of the inlet edge is only limited controllable and consequently the rounding of the respective inlet edge of spray hole to spray hole can vary widely with constant constant flow of the fluid medium.
• the method with the features of claim 1 has the advantage that by defining two flow channels, which are brought together only in the immediate vicinity of the inlet edge of the bore to be processed and their pressures are set independently of each other, one compared to the prior art significantly better control of the rounding process can be achieved by the inflow at the spray hole inlet or the leading edge of the bore to be machined defined controlled.
• the thereby taking place material removal at the inlet edge of the bore is thus defined and can be controlled both locally and quantitatively.
• a significant reduction of the rejects in the production of components is thereby achieved over the prior art.
• when using the method according to the invention for rounding spray holes in injection nozzles or injectors is achieved by the defined controllable removal of material at the inlet edge of the spray hole a relation to the prior art significantly increased reliability of the invention processed component.
• FIG. 1 is a longitudinal sectional view of a nozzle body, in which in a conventional manner an obstacle body is inserted into the interior of the nozzle body and is positioned in the vicinity of a bore to be machined, wherein an abrasive particles having fluid medium in the interior of the nozzle body flows around the obstacle body, accelerated flows to the inlet edge of the bore and passes through the bore, as well
• FIG. 2 shows a sectional view of a nozzle body, in which, according to the invention, a hollow needle-shaped body is introduced into the interior and is to be worked in the vicinity of a body positioned injection hole, whereby a substantially annular formed first flow channel between the wall of the nozzle body and the outer wall of the hollow cylindrical body and a second substantially centrally extending flow channel are defined, in which media with different adjustable pressures reach the inlet edge of the bore and the bore flow through.
• FIG. 2 illustrates, in a partial view, a longitudinal section of a right-side section of a nozzle body 100 in order to explain the method according to the invention.
• a hollow needle-shaped or hollow cylindrical body 102 is introduced, of which in Fig. 2, only one with respect to the longitudinal axis 107 of the nozzle body 100 right side wall portion is shown.
• the wall 103 of the nozzle body 100 which limits the interior 101 of the nozzle body 100 to the outside, is penetrated by a bore 104.
• the hollow needle-shaped body 102 is positioned within the interior 102 such that its downstream end 102 ' faces the inlet edge 105 of the bore 104 to be machined.
• two flow channels 1 1 1, 1 12 are provided according to the invention in the interior 101 of the nozzle body 100.
• a first flow channel 1 1 1 extends through the intermediate space arranged annularly between the outer wall of the hollow needle-shaped body 102 and the wall 103 of the inner space 101, while a second flow channel 1 12 extends through the interior of the hollow needle-shaped body 102.
• Each of the two flow channels 1 1 1, 1 12 is associated with a respective not shown in Fig. 1 reservoir, each having a fluid medium with highly abrasive abrasive particles. From each reservoir, the respective fluid medium is pumped via a line into the corresponding flow channel 1 1 1, 1 12 or inlet channel under a respective individually adjustable pressure, so that the fluid medium in the first flow channel 1 1 1 under a certain pressure p- ⁇ and the
• Fluid medium in the second flow channel 1 12 under a certain pressure p 2 flows.
• the hollow needle-shaped body 102 guiding the second flow channel 12 is introduced into the inner space 101 of the nozzle body 100 such that its downstream end 102 'is positioned in the vicinity of the bore 104 to be machined so that both flow channels 11 1 1, 12 are located downstream End 102 'of the hollow needle-shaped body 102 in front of the drilling 104 are merged.
• due to the orientation of the downstream end 102 'of the hollow needle-shaped body 102 on the bore 104 extends the course of the boundary layer 106 between the flow channels 1 1 1, 1 12 from the downstream end 102 ' of the hollow needle-shaped body 102 into the injection hole 104 into it.
• the media flowing in the two flow channels 11 1, 12 each then strike the inlet edge 105 of the injection hole 104 to be processed and pass through the injection hole 104 of the nozzle body 100 to the outside.
• the flow and thus the rounding of the injection hole 104 is controlled by in both flow channels 1 1 1, 1 12 different pressures pi and p 2 are set, which are also still temporally variable. If, for example, the pressures pi and p 2 are set or selected so that the prevailing in the second flow channel 1 12 pressure p 2 is greater than the pressure p- ⁇ in the first flow channel 1 1 1, defined in the course of the invention
• An optimization of the method according to the invention, with which the material can be removed even more precisely and locally defined, provides that the respective concentration of abrasive particles in each of the flow channels 1 1 1, 1 12 is set individually.
• the particular particle density in the flow channels 1 1 1, 1 12 is selected so that the fluid medium, which flows along the inside of the hollow needle-shaped body 102 extending second flow channel 1 12, has a high particle density, while the fluid medium, which flows along the other flow channel 1 1 1, has a lower particle density.
• the medium flowing along the second flow channel 1 12 develops a greater abrasive effect than the medium having the lower particle density flowing in the other flow channel 1 1 1.
• the grain size of the abrasive particles is chosen differently for each of the flow channels 111, 112.
• the viscosity of the flow media for each of the flow channels 111, 112 is selected differently.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Nozzles (AREA)

Applications Claiming Priority (2)

Publications (1)

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Country Status (2)

Cited By (4)

Families Citing this family (1)

Citations (3)

• 2012
  • 2012-06-27 DE DE102012211000.3A patent/DE102012211000A1/de not_active Withdrawn
• 2013
  • 2013-05-15 WO PCT/EP2013/060057 patent/WO2014000954A1/fr not_active Ceased

Patent Citations (3)

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