CN106363306A - Machining method and system for oil nozzle spray hole - Google Patents

Abstract

The invention relates to a system and method for processing a spray hole of a fuel injector, comprising: a laser and an optical rotation device; the laser is used to emit pulsed laser light; the optical rotation device includes a prism group and a focusing mirror arranged on a common rotation axis; The optical axis of the laser is coaxial; the prism group is used to deflect and/or displace the pulsed laser relative to the optical axis; The formed focused spot moves circularly on the surface of the material to be processed. The technical solution provided by the embodiment of the present invention provides a new idea for high-quality and high-efficiency processing of nozzle holes of fuel injectors, which can process holes with variable hole diameter and taper, and can design and process inverted tapered high-quality holes , to improve the atomization effect of the nozzle hole.

Description

A method and system for processing nozzle holes of a fuel injector

technical field

The invention relates to the technical field of mechanical processing, in particular to a method and system for processing nozzle holes of an oil injector.

Background technique

With the increasing calls for global environmental protection, motor vehicle exhaust emission standards are becoming more and more stringent. Since 2005, Europe has begun to implement the Euro IV standard, and in 2008 the Euro V standard will be fully implemented. In 2006, the European Union formulated the Euro VI standard, which is expected to be implemented in 2014. my country plans to implement the third and fourth phases of national motor vehicle emission standards (equivalent to Euro III and Euro IV standards) in 2007 and 2010 respectively, and major cities such as Beijing and Shanghai will implement the third phase of national standards on December 30, 2005. . These standards have made increasingly strict requirements on the content of nitrogen oxides and particulate matter in motor vehicle exhaust.

As the core component of motor vehicles, the engine plays a decisive role in exhaust emissions. Among the engines, the diesel engine has the characteristics of low fuel consumption, strong power, durability, high thermal efficiency, etc., so that its proportion in all kinds of engines is increasing year by year. For diesel engines, the performance of the fuel injection system directly affects the performance of the diesel engine and the amount of harmful substances in the exhaust gas. As an important part of the fuel injection system, the size, shape, inlet fillet and inner surface topography of the nozzle hole have a great influence on the flow coefficient of the nozzle hole, the spray range, the uniformity of the diameter of the droplet, and the uniformity of the mixture of fuel and air. Sex has a very significant impact.

At present, the diameters of nozzle holes produced by many major foreign fuel injector manufacturers that meet the Euro IV standard range from 100 μm to 200 μm, and the diameter difference between the inlet and outlet of the injection holes used is between 0 μm and 30 μm. The hole depth is between 1 and 2mm. Since the fuel injector material of diesel engine is mostly stainless steel (such as 18CrNi8). The manufacture of engine fuel injection holes has the following trends: 1) Aperture miniaturization: the diameter of traditional injection holes is 0.2 mm, and now the diameter of ultra-multi-injection holes is 0.09 mm or even smaller. 2) The quality requirements are constantly pushed to new extremes: microhole size, shape, positioning accuracy, roundness, taper, depth-to-diameter ratio, position accuracy, processing residues in the cavity, and internal and external surface roughness are all required. The requirements for heat-affected zone, reliability, service life, energy density, repeatability and uniformity of small hole processing are constantly increasing; 3) High efficiency: the fuel injectors of different engines have uncertain hole patterns and hole positions, which need to be adjusted in each Six to a dozen holes are processed on the nozzle. How to ensure the efficiency in the processing of these holes is the key to mass production.

In response to these challenges, the traditional nozzle hole manufacturing methods are difficult to meet the requirements in terms of processing accuracy and processing efficiency, and it is very difficult to implement, and some even cannot be processed. At present, the domestic methods for processing the nozzle holes of fuel injectors include: manual drilling; CNC three-axis drilling machine drilling nozzle holes; EDM nozzle hole machining nozzle holes. Manual hole turning has low precision and low efficiency, and it is impossible to process multi-jet holes. The reverse taper hole cannot be processed by CNC three-axis drilling machine drilling spray hole and manual hole turning method. EDM improves the machining of fuel injection holes to a new level, and the aperture scale and accuracy are greatly improved, but its accuracy is affected by electrode wire, deionized water, and discharge procedures, and its efficiency is restricted. In addition, the nozzle holes processed by the traditional processing method also need subsequent processing, such as the nozzle hole extrusion grinding process and the electrolysis deburring process of the pressure chamber nozzle hole.

Contents of the invention

The technical problem to be solved by the present invention is to provide a high-efficiency and high-quality fuel injection nozzle hole processing system.

For this purpose, an embodiment of the present invention provides a nozzle hole processing system, the system includes: a laser and an optical rotation device; the laser is used to emit pulsed laser light; the optical rotation device includes a prism set with a common rotation axis and a focusing mirror; the rotation axis of the optical rotation device is coaxial with the optical axis of the pulsed laser;

The prism group is used to deflect and/or displace the pulsed laser light relative to the optical axis;

The focusing mirror is used to focus the pulsed laser light passing through the prism group on the surface of the material to be processed;

Wherein, the optical rotation device rotates around the rotation axis, so that the formed focused light spot moves in a circle on the surface of the material to be processed.

Preferably, the prism group includes a first optical wedge and a second optical wedge whose main sections are parallel, and the pulsed laser enters the first optical wedge from the main section of the first optical wedge and passes through the first optical wedge. an optical wedge and a second optical wedge projecting from the main section of the second optical wedge;

Wherein, the first optical wedge and the second optical wedge are arranged so that the pulse laser is displaced relative to the optical axis by changing the relative distance between the first optical wedge and the second optical wedge.

Preferably, the prism group further includes a third optical wedge and a fourth optical wedge; the pulsed laser light passes through the third optical wedge after being emitted from the main section of the second optical wedge, and from the third optical wedge The main section of the wedge is emitted, and enters the fourth optical wedge from the main section of the fourth optical wedge, and exits after passing through the fourth optical wedge;

Wherein, the third optical wedge and the fourth optical wedge are configured to deflect the pulsed laser light relative to the optical axis by changing the relative angle between the third optical wedge and the fourth optical wedge.

Preferably, the output end of the laser is provided with an optical gate; the output end of the optical gate is provided with a first reflector; the output end of the first reflector is connected with a beam expander; the output of the beam expander The end is connected with a second reflector; the output end of the second reflector is connected with the optical rotation device.

Preferably, the laser is a picosecond green pulse laser.

Preferably, the system further includes: an air blowing device; the inflating device is used to blow compressed air to the surface of the material to be processed.

The embodiment of the present invention also provides a method for processing the nozzle holes of the fuel injector by using any one of the nozzle hole processing systems described above, the method comprising:

emitting pulsed laser light through the laser;

Deflecting and/or displacing the pulsed laser light relative to the optical axis through the prism group;

Focusing the pulsed laser light passing through the prism group on the surface of the material to be processed through the focusing lens; wherein, the formed focused spot moves in a circle on the surface of the material to be processed.

Preferably, the displacement of the pulsed laser relative to the optical axis through the prism group specifically includes:

The prism group includes a first optical wedge and a second optical wedge whose main sections are parallel, and the pulsed laser light enters the first optical wedge from the main section of the first optical wedge and passes through the first optical wedge and the second optical wedge. a second optical wedge emitting from a main section of the second optical wedge;

The pulsed laser light is displaced relative to the optical axis by changing the relative distance between the first optical wedge and the second optical wedge.

Preferably, the deflecting of the pulsed laser light relative to the optical axis through the prism group specifically includes:

The prism group also includes a third optical wedge and a fourth optical wedge; the pulse laser passes through the third optical wedge after being emitted from the main section of the second optical wedge, and passes through the main section of the third optical wedge. cross-section, and enter the fourth optical wedge from the main section of the fourth optical wedge, and exit after passing through the fourth optical wedge;

The pulsed laser light is deflected relative to the optical axis by changing the relative angle between the third optical wedge and the fourth optical wedge.

Preferably, the method also includes:

The pulsed laser light emitted by the laser is injected into the optical rotation device through the optical shutter, the first reflector, the beam expander and the second reflector arranged in sequence.

The injection nozzle hole processing system and method provided by the embodiments of the present invention provide a new idea for high-quality and high-efficiency processing of the injection nozzle hole. The pulse laser is generated relative to the optical axis through the prism group in the optical rotation device Deflection and/or displacement can process hole patterns with variable aperture and taper, and the rotating device rotates around the optical axis to realize rotary cutting and drilling. It can design and process inverted tapered high-quality holes to improve the injection nozzle Hole atomization effect.

Description of drawings

The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the accompanying drawings:

Fig. 1 is a schematic structural view of a nozzle hole processing system provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of an optical rotation device provided by an embodiment of the present invention;

Fig. 3A-Fig. 3D are the schematic diagrams of the principle of processing the nozzle holes of different hole types;

Fig. 4 is a schematic flow chart of a method for processing a nozzle hole of a fuel injector according to an embodiment of the present invention.

detailed description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in Figure 1, the embodiment of the present invention provides a nozzle hole processing system, the system includes: a laser 1 and an optical rotation device 6; the laser is used to emit pulsed laser light 11; the optical rotation device 6 includes a common A prism group and a focusing mirror 65 provided with a rotation axis; the rotation axis of the optical rotation device 6 is coaxial with the optical axis of the pulse laser 11;

The prism group is used to deflect and/or displace the pulsed laser light 11 relative to the optical axis; the focusing lens 65 is used to focus the pulsed laser light 11 passing through the prism group on the surface of the material to be processed; Wherein, the optical rotation device 6 rotates around the rotation axis, so that the formed focused light spot moves in a circle on the surface of the material to be processed.

Specifically, the laser 1 may be a picosecond green pulse laser. The output wavelength of the picosecond green pulse laser is 532nm green ultrashort pulse laser beam. The metal material has a high absorption rate for the beam in this wavelength band, so that the energy at the focused spot can be fully utilized and the thermal effect during processing can be reduced. The pulse width of the laser is on the picosecond level, and its single pulse power is 1000 times that of the nanosecond pulse power. When processing materials, it is close to cold processing, and the materials are directly vaporized without passing through the molten state, so the processed micropore surface has less splash residue. , the heat-affected zone is small, and there is almost no recasting layer formed, so that the edge of the small hole is smooth, and there is no burr on the inner wall. It is an application laser with both processing efficiency and processing quality.

As shown in Figure 1, the output end of the laser 1 is provided with an optical gate 2; the output end of the optical gate 2 is provided with a first reflector 3; the output end of the first reflector 3 is connected with a beam expander 4; The output end of the beam expander 4 is connected with a second reflector 5 ; the output end of the second reflector 5 is connected with the optical rotation device 6 . In the optical path transmission, the optical gate 2 plays an external control of laser on-off, and can block the laser when it is not in the processing state, and also plays a certain protective role to prevent the operator from being injured accidentally. The magnification of the beam expander 4 is adjustable from 3 to 10 times, and its function is to expand and collimate the diameter of the laser beam, so that the parallelism of the outgoing beam is better, which is conducive to focusing the beam in the subsequent system. The reflector mainly plays the role of optical path deflection, and the distance between the reflector and the beam expander 4 has no specific limitation, but its position should be kept horizontally or vertically as far as possible in the center of the lens during mechanical design (the optical path angle in Fig. 1 For the right angle), in order to facilitate the adjustment of the optical path.

Specifically, the pulse laser 11 is radiated from the laser 1, passes through the shutter 2 and the first reflector 3, obtains a collimated and uniform beam after being corrected by the beam expander 4, and enters the optical rotation device 6 after being reflected by the second reflector 5 Inside, the beam is focused by the focusing mirror 65 in the optical rotation device 6 and applied to the material to be processed. When drilling, the laser focus is located on the surface of the material, and it is gradually fed as the hole depth increases. By adjusting the material to be processed and the The relative height of the optical rotation device 6 can make the laser focus always be on the surface of the material to be processed. The rotation axis of the optical rotation device 6 is coaxial with the optical axis. During processing, the optical rotation device 6 can be driven by a motor to rotate around the optical axis, so that the spot focused by the focusing mirror 65 makes a high-speed circular motion on the surface of the processed material around the optical axis to form a laser ring. cut. During the processing, by adjusting the position and angle of the prism inside the optical rotation device 6 in real time, the pulse laser 11 can be deflected and/or displaced relative to the optical axis, and holes with variable aperture and taper can be processed.

The fuel injection nozzle hole processing system provided by the embodiment of the present invention provides a new idea for high-quality and high-efficiency processing of the fuel injection nozzle hole. The pulsed laser is deflected and / or displacement, can process holes with variable aperture and taper, and the rotating device rotates around the optical axis to realize rotary cutting and drilling, and can design and process inverted tapered high-quality holes to improve the spray hole of the fuel injector Atomization effect.

As shown in FIG. 2 , in order to make the pulsed laser 11 shift relative to the optical axis, on the basis of the above-mentioned embodiments, the prism group includes a first wedge 61 and a second wedge 62 whose principal sections are parallel, so The pulsed laser light 11 enters the first optical wedge 61 from the main section of the first optical wedge 61, passes through the first optical wedge 61 and the second optical wedge 62, and passes through the main section of the second optical wedge 62. Cross-sectional injection;

Wherein, the first optical wedge 61 and the second optical wedge 62 are arranged to make the pulse laser 11 relative to the optical axis by changing the relative distance between the first optical wedge 61 and the second optical wedge 62 Displacement occurs.

Specifically, by adjusting the distance between the first optical wedge 61 and the second optical wedge 62, the beams emitted through the first optical wedge 61 and the second optical wedge 62 can be displaced by a certain distance relative to the optical axis without changing the laser beam The angle between the laser beam and the optical axis does not change the propagation direction of the beam, and then can control the propagation direction of the focused laser, and indirectly control the taper of the laser punched hole. Therefore, by adjusting the distance between the first optical wedge 61 and the second optical wedge 62, the taper of the nozzle hole of the fuel injector can be controlled.

As shown in Fig. 2, in order to cause the displacement and deflection of the pulse laser 11 relative to the optical axis, the prism group also includes a third optical wedge 63 and a fourth optical wedge 64; The main section of the optical wedge 62 passes through the third optical wedge 63 after exiting, exits from the main section of the third optical wedge 63, and enters the fourth optical wedge from the main section of the fourth optical wedge 64. 64, and shoot out after passing through the fourth optical wedge 64;

Wherein, the third optical wedge 63 and the fourth optical wedge 64 are arranged to make the pulse laser 11 relative to the optical axis by changing the relative angle between the third optical wedge 63 and the fourth optical wedge 64 Deflection occurs.

Specifically, the main sections of the third optical wedge 63 and the fourth optical wedge 64 shown in FIG. A certain angle can change the relative angle between the third optical wedge 63 and the fourth optical wedge 64, so that the pulsed laser light 11 passing through the third optical wedge 63 and the fourth optical wedge 64 is deflected relative to the optical axis, that is, the distance between the optical axis and the optical axis The angle between them changes, and then the distance between the focal point and the optical axis after focusing can be changed, thereby controlling the size of the punched hole. That is, adjusting the relative angle between the third optical wedge 63 and the fourth optical wedge 64 can change the size of the hole diameter, and can process nozzle holes with diameters ranging from tens to hundreds of microns.

As shown in Figure 3A-Figure 3D, in the specific processing process, real-time adjustment of the distance between the first wedge 61 and the second wedge 62 and the relative angle between the third wedge 63 and the fourth wedge 64 can change the beam propagation. Angle, so as to process the pass with variable hole diameter and taper. The distance a in Fig. 3A-Fig. 3D represents the aperture (not marked in the taper diagram).

It should be noted that, as required, only the first optical wedge 61 and the second optical wedge 62 can be provided, and by changing the distance between the first optical wedge 61 and the second optical wedge 62, the pulsed laser 11 is displaced relative to the optical axis , to change the taper of the injector nozzle hole, thereby forming a variable taper nozzle hole with a fixed aperture. According to needs, only the third optical wedge 63 and the fourth optical wedge 64 can be provided. By changing the relative angle between the third optical wedge 63 and the fourth optical wedge 64, the pulse laser 11 is deflected relative to the optical axis, and the fuel injection nozzle can be changed. The diameter of the nozzle hole, thus forming a nozzle hole with a fixed taper and a variable diameter. In order to control the aperture and taper at the same time, the first optical wedge 61 , the second optical wedge 62 , the third optical wedge 63 and the fourth optical wedge 64 need to be installed at the same time, so that the pulsed laser 11 is displaced and deflected relative to the optical axis.

Further, in order to remove debris and steam on the surface of the material in time, so as not to affect the subsequent processing, the nozzle hole processing system provided by the embodiment of the present invention also includes: an air blowing device; The surface of the processed material is blown with compressed air, so that the debris and steam on the surface of the material can be taken away in time.

On the other hand, as shown in Fig. 4, the embodiment of the present invention also provides a method for processing the nozzle hole of the fuel injector by using the nozzle hole processing system provided in the above embodiment, the method includes:

S1: emit pulsed laser light 11 through the laser 1;

S2: deflecting and/or displacing the pulsed laser 11 relative to the optical axis through the prism group;

S3: Using the focusing mirror 65 to focus the pulsed laser light 11 passing through the prism group on the surface of the material to be processed; wherein, the formed focused spot moves in a circle on the surface of the material to be processed.

The injection nozzle hole processing method provided by the embodiment of the present invention provides a new idea for high-quality and high-efficiency processing of the injection nozzle hole. The pulsed laser is deflected and / or displacement, can process holes with variable aperture and taper, and the focus spot rotates around the optical axis to realize rotary cutting and drilling, and can design and process inverted tapered high-quality holes to improve the nozzle hole of the fuel injector Atomization effect.

Further, the displacement of the pulse laser 11 relative to the optical axis through the prism group specifically includes:

The prism group includes a first wedge 61 and a second wedge 62 whose principal sections are parallel, and the pulsed laser 11 enters the first wedge 61 from the principal section of the first wedge 61 and passes through the The first optical wedge 61 and the second optical wedge 62 emit from the main section of the second optical wedge 62;

By changing the relative distance between the first optical wedge 61 and the second optical wedge 62, the pulse laser 11 is displaced relative to the optical axis, so that the taper of the nozzle hole of the fuel injector can be changed.

Further, the deflection of the pulsed laser light 11 relative to the optical axis through the prism group specifically includes:

The prism group also includes a third optical wedge 63 and a fourth optical wedge 64; the pulse laser 11 passes through the third optical wedge 63 after emitting from the main section of the second optical wedge 62, and passes through the third optical wedge 63 from the first optical wedge 64. The main section of the three optical wedges 63 is emitted, and enters the fourth optical wedge 64 from the main section of the fourth optical wedge 64, and exits after passing through the fourth optical wedge 64;

By changing the relative angle between the third optical wedge 63 and the fourth optical wedge 64, the pulsed laser light 11 is deflected relative to the optical axis, so that the diameter of the nozzle hole of the fuel injector can be changed.

Further, the method for processing the nozzle hole of the fuel injector provided by the embodiment of the present invention further includes:

The pulsed laser light 11 emitted by the laser 1 is injected into the optical rotation device 6 through the shutter 2 , the first reflector 3 , the beam expander 4 and the second reflector 5 arranged in sequence.

Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention. within the bounds of the requirements.

Claims (10)

1. A nozzle hole processing system, characterized in that it comprises: a laser and an optical rotation device; the laser is used to emit pulsed laser light; the optical rotation device includes a prism group and a focusing mirror that are co-rotating; The rotation axis of the optical rotation device is coaxial with the optical axis of the pulsed laser; The prism group is used to deflect and/or displace the pulsed laser light relative to the optical axis; The focusing mirror is used to focus the pulsed laser light passing through the prism group on the surface of the material to be processed; Wherein, the optical rotation device rotates around the rotation axis, so that the formed focused light spot moves in a circle on the surface of the material to be processed. 2. The system according to claim 1, wherein the prism group comprises a first optical wedge and a second optical wedge whose main sections are parallel, and the pulsed laser light enters the optical wedge from the main section of the first optical wedge. The first optical wedge passes through the first optical wedge and the second optical wedge, and emits from the main section of the second optical wedge; Wherein, the first optical wedge and the second optical wedge are arranged so that the pulse laser is displaced relative to the optical axis by changing the relative distance between the first optical wedge and the second optical wedge. 3. The system according to claim 2, wherein the prism group further comprises a third optical wedge and a fourth optical wedge; the pulsed laser passes through the second optical wedge after being emitted from the main section of the second optical wedge The third optical wedge is emitted from the main section of the third optical wedge, enters the fourth optical wedge from the main section of the fourth optical wedge, and exits after passing through the fourth optical wedge; Wherein, the third optical wedge and the fourth optical wedge are configured to deflect the pulsed laser light relative to the optical axis by changing the relative angle between the third optical wedge and the fourth optical wedge. 4. The system according to claim 1, wherein the output end of the laser is provided with an optical gate; the output end of the optical gate is provided with a first reflector; the output end of the first reflector is connected to There is a beam expander; the output end of the beam expander is connected with a second reflection mirror; the output end of the second reflection mirror is connected with the optical rotation device. 5. The system according to claim 1, wherein the laser is a picosecond green pulse laser. 6. The system according to claim 1, further comprising: an air blowing device; the inflating device is used to blow compressed air to the surface of the material to be processed. 7. A method for processing a nozzle hole by using the nozzle hole processing system according to any one of claims 1-6, characterized in that the method comprises: emitting pulsed laser light through the laser; Deflecting and/or displacing the pulsed laser light relative to the optical axis through the prism group; Focusing the pulsed laser light passing through the prism group on the surface of the material to be processed through the focusing lens; wherein, the formed focused spot moves in a circle on the surface of the material to be processed. 8. The method according to claim 7, wherein the displacing the pulsed laser light relative to the optical axis through the prism group specifically comprises: The prism group includes a first optical wedge and a second optical wedge whose main sections are parallel, and the pulsed laser light enters the first optical wedge from the main section of the first optical wedge and passes through the first optical wedge and the second optical wedge. a second optical wedge emitting from a main section of the second optical wedge; The pulsed laser light is displaced relative to the optical axis by changing the relative distance between the first optical wedge and the second optical wedge. 9. The method according to claim 8, wherein the deflecting the pulsed laser light relative to the optical axis through the prism group specifically comprises: The prism group also includes a third optical wedge and a fourth optical wedge; the pulse laser passes through the third optical wedge after being emitted from the main section of the second optical wedge, and passes through the main section of the third optical wedge. cross section, and enter the fourth optical wedge from the main section of the fourth optical wedge, and exit after passing through the fourth optical wedge; The pulsed laser light is deflected relative to the optical axis by changing the relative angle between the third optical wedge and the fourth optical wedge. 10. The method according to claim 7, further comprising: The pulsed laser light emitted by the laser is injected into the optical rotation device through the optical shutter, the first reflector, the beam expander and the second reflector arranged in sequence.