JPH01500022A - Flow resistance control method in fluid orifice manufacturing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Flow resistance control method in fluid orifice manufacturing Field of the invention This invention belongs to the field of abrasive flow machining, and in particular, the inner wall polishing of a fluid passage orifice. The present invention relates to a method for controlling flow resistance in manufacturing a fluid orifice.

Background of the invention Fluid exit through an orifice is widely used and is commonly used at the tip of a fuel injection nozzle. Examples include parts, carburetor jets, precision bearing lubrication meters, etc. . Despite the critical importance of flow measurement in these applications, manufacturing processes At present, it is difficult to measure accurately due to problems that occur in equipment. Ru. Even minute variations in manufacturing tolerances during the manufacturing process can cause problems with flow resistance and flow rate. This will bring about huge changes.

Parts with fluid outflow orifices are produced by a wide variety of casting and machining techniques. For example, high-quality investment casting methods are often It has been adopted. Dimensional differences, especially wall thickness, are important in parts manufactured using these manufacturing methods. etc., may cause misalignment of the central axis and affect distortion, and may also cause surface roughness. There are problems with bumps, scratches, holes, or raw metal. In extreme cases, the core Microscopic cracks inside cause thin walls and the presence of protrusions in the internal fluid passages. becomes. All these artifacts are obstacles to fluid outflow.

Commonly used machining methods, such as regular drilling and electrical discharge machining, as well as somewhat unusual machining methods. However, laser, electron photoelectric flow, STEM drilling methods, etc. There is a considerable deviation in resistance, and satisfactory precision machining cannot be obtained. these The most precise of the methods is probably electrical discharge machining, but it Due to the variation in the length of the inner passages, even if the diameter of the hole is the same, the flow resistance This results in fluctuations in resistance, making it impossible to obtain uniform flow resistance. Furthermore, there are variations in the EDM method. This is unavoidable, and variations may occur in dimensions, shape, surface finish, end shape, etc. .

Currently, these mutations are taken for granted and have a wide tolerance. There is a degree of freedom in the design of the person in charge, and performance or efficiency is For example, in a pressure fuel-injected internal combustion engine, When injecting fuel, it is necessary to detect the flow rate at the injector. flow rate The more precisely the engine can be adjusted, the higher the fuel efficiency and engine efficiency will be. Currently, this The design of these fuel sensing schemes is often based on actual flow resistance measurements and is initially determined. A method is used to select parts within the specified tolerance range. This method uses a large amount It costs a lot of money because parts need to be kept in stock. In addition, defective products are discarded , or it will require rework, which will cost a lot of money. For the time being, the injection nozzle is Machined with machined flow meter orifice. As shown in Figure 1 The most important conditions for determining flow resistance are the diameters of orifices 1o and 11 and A- These are the thickness of the wall of the A line, the condition of the end, and the roughness and finish condition of the surface.

The design specs are that the wall thickness is 0.040 inches at this point, +0. 002 inches, and parts that do not fall within this range are considered defective. Recognized as a good product The parts are delivered in 8 categories and divided into 0.00025 inch increments. . The wall pressure A-A is an indirect determining condition for the flow resistance of the orifice 10.11. It is a well-known fact that precise diameter control of orifices 10 and 11 directly affects the flow resistance. It is known to directly determine resistance.

These parameters determine flow conditions and more directly measure flow resistance. It is also desired to directly control flow resistance during production.

Another important example of the precision of flow resistance through an orifice is the An example is the measurement of the amount of cooling air in a gas turbine engine component. Figure 3 As shown in Figure 4, enclosed cast-in turbine blades are normally cast in The dolphin is drilled (laser drill, STEM drill, electrical discharge machining) Drill multiple holes, typically 0.010 to 0.030 inches in diameter, to create an internal passageway. near the leading edge, trailing edge, or along the airfoil. It penetrates the sides. Cooling air is sent under pressure from inside and exits through multiple holes. Occasionally, it passes through the inner wall of the plaid. Measure the distribution of cooling air through the holes. Naturally, the difference in flow resistance is the difference in cooling effect. This can cause high temperature areas, disrupt the thermal balance within the parts, and affect the engine. It affects its performance and the lifespan of its parts.

The amount of cooling air should be kept to the minimum necessary; if it is too large, it will reduce engine efficiency. Geru. This is due to the compressor using too much energy. orifice Precise control of the flow resistance of the It brings great benefits to the industry.

Although there are many other examples of flow control orifices to which the present invention can be applied, the above examples are This is a typical example and shows an example that can be improved or solved by the present invention. Furthermore, the present invention The purpose is to provide a method for manufacturing precision flow control orifices. even more precise The purpose is to provide a method of obtaining a predetermined flow resistance.

Additionally, the ability to very closely match flow resistance to multiple flow control orifices It is in. Multiple components with predetermined flow resistance that are more precise and reproducible Provides a method for continuous production. It also directly or indirectly affects flow resistance. A method of manufacturing an orifice with a predetermined flow resistance value using a manufacturing method that controls conditions. provide law. Orifice with reproducible precision, predetermined flow resistance provide parts or products based on

It also aims to provide tuned turbine engine parts.

Cry” LΩJJ The present invention uses a polishing method by passing through an orifice, and provides a stable, predetermined A fluid target where a dynamic amount of abrasive passes directly through the orifice, using an abrasive flow that It is related to quantity. It is possible to maintain a constant flow of abrasive material, and it is also possible to maintain a constant flow of abrasive material. It is also possible to control the amount of rotation of the operating piston. Viscosity or flow rate is determined If the other conditions are orifice size and media viscosity, Figure 1 shows the fuel injector meter. Fig. 2 is a detailed enlarged view of a part of Fig. 1, showing the orimeter with a meter. It shows fiss 10 and 11, Figure 3 is a cross-sectional view of the turbine/plaid, with metered orifices for cooling air and It shows the leading edge, trailing edge, error foil and inner wall, and 4 shows an overall view of the turbine blade of FIG. 3.

The Emperor's Arms Polishing phase flow machining is widely applied to metal work, etc. Especially finished on the inside, bore - Often used for processing and finishing openings, complex three-dimensional shapes, difficult work, etc. . Polishing flow is particularly important for other machining methods such as deburring, radius creation, polishing and finishing, etc. Often used for extremely difficult interior processing. Of course, the orifice to which this invention relates As is well known, the flow resistance of the orifice is reduced by abrasive phase flow processing. The size of the orifice can also be expanded a little.

In the polishing process in this invention, the object to be processed is a viscoelastic plastic material containing an abrasive. This is a machining method achieved by passing the surface under pressure. flow is restricted When the workpiece is polished, the fluid has an abrasive force and the workpiece is polished. Typically, the workpiece is static An abrasive material containing a viscoelastic plastic material is formed by a machined object that is held in a stationary state. The surface of the workpiece is brought to the desired surface finish by the pumping device. This abrasive material is supplied until the Typically, a hydraulic cylinder carries this abrasive material. Used to supply the right amount. Workpieces within the range where the flow of this abrasive material cannot be blocked The abrasive material used in this invention contains cutting oil and honing oil. , does not contain liquid media such as those used in gas streams, and is semi-solid and stable. This polymer component is limited to a polymer component that has plasticity or extrusion properties. It forms a stable, non-separating diffusion where it flows due to force.

In such abrasive phase flow machining, in normal applications, the tooling has the above-mentioned characteristics. It is used to direct and determine the flow of the abrasive media to take advantage of the There is. If the part or workpiece undergoes light machining, normal deburring, and/or polishing, including polishing, but with multiple sizes determined to be sufficient to carry out the It will be processed as a culprit. In general, coarse abrasives are used for rough surfaces, and coarse abrasives are used for fine surfaces. A fine abrasive material is used for the surface, but in the abrasive phase flow processing referred to here, it is especially difficult to use. This is because the metal piece must be removed from the workpiece before it can be polished. This means that a continuous flow of abrasive material cannot be obtained, and if these metal pieces remain, high This is because a surface that has been polished to a certain degree also becomes a rough surface. Abrasive media and extrusion By combining various polishing rates, the polishing characteristics of any combination can be virtually It is something that can be obtained.

Abrasive phase flow processing uses materials that uniformly contain a semi-solid abrasive material such as plastic. Ru. The purpose of using this semi-solid medium is to remove abrasive particles from protrusions on the rough surface of the workpiece. The purpose is to remove the

Another purpose is that the semi-solid medium keeps the abrasive dispersed, so that this The polishing effect is good and the finished surface is evenly pressed. It will be distributed evenly.

Additionally, semi-solid media are relatively stiff and supportive, allowing the abrasive to hold up under pressure. It has good cutting force on the surface of the workpiece and can reach all finished surfaces. It has sufficient plasticity to reach the desired value.

containing an abrasive and extruded through the same type of workpiece processed by this invention The liquid slurry does not require polishing if it does not uniformly cover all surfaces. It is noteworthy that the force is neither applied nor evenly applied to the workpiece surface. these The liquid slurry of It does not provide any collisions, and therefore part of the surface does not undergo any abrasion at all. Under such conditions, some parts will not undergo any polishing.

The abrasive material in this abrasive process and the abrasive material carried by liquid or air or gas. The difference is noteworthy. In polished machining, the medium is semi-solid and the pressure It passes through the product underneath to provide maximum polishing power and a uniform finish. The speed will be relatively low so that you can Those using liquid or air as a medium have high speed and low speed. It depends on the pressure. Semi-solid and difficult-to-flow gel-like media are suitable for abrasive phase flow processing. , it provides a firm holding force to the abrasive material and is effective while passing through the surface of the workpiece. . In other methods using liquid or air as a medium, collisions of abrasive particles due to high velocity Process more. At the connection point of two surfaces, an acute angle usually occurs that requires blending. live. During its passage over the workpiece, the direction changes at this point. The change in flow direction is °, since this semi-solid is a difficult medium to flow, such connection points and their surfaces are The polishing effect increases on the surface. Conversely, abrasive particles with a liquid or air medium The abrasive force decreases at direction change values such as , and at high speeds it becomes a turbulent medium. As a result, there are areas where there are no abrasive particles, and at points where there is a change in direction, no abrasive particles are present at all. The medium in this invention has no resultant potential to flow in a semi-solid state. It is a plastic material and is uniformly penetrated by finely crushed abrasive particles. This issue In this case, the plasticizer medium has sufficient density even at high pressure and low speed. , the abrasive particles are pressed against the surface of the workpiece with sufficient pressure to produce the expected results. One suitable transport medium for abrasive particles is silicone putty, i.e. polymer ( Borosiloxane), for example, listed as 5S-91 of General Electric Co. Available in the indicated grade. In this medium, 12 g of putty balls are 70 to 78 ’F from 100 inches above onto a flat sawbstone block. It has a rebound of 25 to 50 percent when exposed to air. This material is from Chicago Measured with a bathore resimeter by Precision Science, Inc. A special 1/2 oz drop at room temperature with 10% to 20% elasticity when It is held in a state accompanied by gravity. This putty is Glision/Universal Using a penetrometer, on a 47.5 g test rod with no external load , has a diameter of 1/4 inch and has the property of penetrating 1.5 to 10 mm in 5 seconds. ing. In this test, this putty is dropped in order to obtain reliable test results. or at least 24 hours after it was first created.

Of course, the abrasive material used within the media putty will vary depending on the intended use. steel processing An effective abrasive material for You can get the following. Another commonly used material is aluminum oxide. In addition, die Yamond dust boron carbide, red iron, corundum, garnet, alundum, Glass and, in special cases, fibers and shell shells are also used.

Typically, the amount of abrasive in the fluid plastic putty is from about 1/10 to about 10% by weight. . Typically it will be 1/3 to 3% by weight.

The workpiece must be secured so that the flow of polishing fluid is restricted over the workpiece surface. be. If the workpiece has openings, special adapters or tools may be required. It may be necessary to direct the abrasive material to a specific aperture or to Guide it to the outside through the opening. This point is a company's technology.

The polishing medium in this invention works as a surface polishing tool, and the polishing powder is added to the polishing medium. It can be said that it is normal because it is included in the tick matrix in a random state. do not have. In the usual concept, polishing stones and laps are stable sand particles, It has a single cut point or edge, which is blunted and used for dressing. It remains in that state until it is removed by work. used in the course of this invention Full-grain particles have all faces and edges used many times. Stay sharp until the end.

Therefore, during polishing flow operation, a constant extrusion cylinder pressure is maintained at a constant number of cycles. Therefore, work is usually done using a fixed amount or abrasive material. child Parameters such as are usually used to obtain appropriate results depending on the work content and tool combination. It will be determined each time.

Care must be taken to avoid local disturbances in flow resistance in the cross section within a specific flow path. There are changes due to flow, such as deburring, brushing, or protruding parts of the workpiece. Selectively removed from the abrasive media stream C:''. Parts for deburring and finishing, Particularly for parts that cannot be accessed effectively using other methods, such as internal passageways or bores. Therefore, the polishing flow processing method is particularly effective. Not only polishing flow processing method but also flow control such as deburring It has been used in parts with orifices and other workpieces.

In addition to all the uses and features mentioned above, abrasive flow machining directly improves the flow resistance of the orifice. The flow of the abrasive material predetermined by the abrasive flow processing industry can be adopted for the control of flow rate through the orifice or dynamic flow resistance of the orifice item being processed. It was discovered by making the resistance equal to constant. Flow resistance during work is directly If the pressure difference is large, it may be related to the flow resistance of other liquids through the orifice. Despite the differences, they were discovered.

The following words are used below:

t: flow time A: Piston area P: Piston pressure applied to the abrasive,: Piston axis movement distance ■, : Piston speed = D, /l Qp: Piston volume change ji = AF XD 80 Niorifice area Po niorifice pressure Do: Orifice axial distance of medium flow ■, : Orifice velocity (ratio) of polishing media flow Qo Flow rate at niorifice The effect of the present invention is to reach a predetermined V0 value at a constant pressure P, Po is A/etc. at the operating pressure of the orifice in the intended working environment. It is related to the benchmark flow ratio of a particular fluid. Experience has shown that this is often However, it can also be theoretically obtained from viscosity, pressure, volume, and orifice dimensions.

For manufactured parts, it is difficult to calculate the target value of vo, and it is uncertain. Also, it is generally not preferred.

Instead, the medium flows at a constant velocity v0 and the orifice pressure drops to a certain Po. By continuing the process until the target value P can be obtained.

■From experience. Determining is easy as follows. That is, the two known is obtained by selecting two standard parts with orifices of . These orifices allow the appropriate working fluid to approach the target flow rate. A known flow rate is obtained at the appropriate pressure to be adjusted. By storing this These parts can be adjusted to predetermined values when using appropriate polishing media. achieved In order to do this, Po is used as a benchmark for comparison. To determine The actual v0 value adopted for a single orifice takes into account the following considerations: Determined by

Q, ,=Q, by definition ■. =D, /l according to definition V, = ni - D, /l　, 1: kodeni = A, /A,.

(Habo constant) D9 and t are easy to measure precisely. is mostly a constant parameter. , 80 changes somewhat as the processing work progresses, so if the time difference t is small, It is effective to treat K as a constant. This approximation method requires that the time interval t is less than about 1 second. It is quite effective in the case of In reality, samples are sampled in the time interval t = 0.1 or less. It is convenient to pull.

The measurements are factual and include the constant P2, temperature, abrasive grain size, and contaminants in the abrasive media. due to the concentration and concentration conditions as well as the constant viscous nature of the abrasive media. These can easily be It is possible to maintain it within the range.

During operation, the determination of the K benchmark and the target value V0 will be compatible with multiple ■. But, D , and t, calculate KD,/l, and operate until the desired value is obtained. You can get it by continuing.

After that, the operation is finished, the parts are removed and cleaned, and the desired vo is obtained. Ru.

As those skilled in the art will appreciate, Pp is an independent variable in abrasive flow machining and is a constant. Of course, a similar result can be obtained if D is a constant and Pp is a variable. , or when both P and Dp are measured simultaneously in variables. like this The operations are equivalent in this invention and are considered part of this invention.

In the case of simultaneous friction flow machining where multiple orifices or multiple parts are processed at the same time. The key considerations are the same.

Of course, as a matter of course, the orifice dimensions of the unmachined part will not be as expected after machining. In order to obtain the target vo, a sufficiently small hole diameter is preferred, especially the Low 5 seconds should require machining time, and by setting it like this, stable operation can be achieved. The condition will be compensated. This eliminates the problem of oversized orifices. It is possible to avoid producing quality products. The goal is to work ■. You can continue until you get the dimensions We will not produce defective products with less than orifice.

In most cases, the amount of material removed in abrasive flow operations is small. Most examples of orifice diameter enlargement are less than 1 mil or 2 to 3 It is about the size of a mil, rarely 20 to 30 mil.

In most cases, simply rounding the end near the entrance of the orifice will provide sufficient flow. It becomes a phenomenon of resistance. By selecting the appropriate abrasive media and machining operating parameters, can be completed in an extremely short time; if the operating time becomes extremely short, measure and adjust. You need to be careful because you may not be able to do this.

The method of this invention is to obtain performance in a specific orifice use, It is important to recognize that it is not possible to obtain fixed dimensions. If the length of the steel is larger than the design value, the core movement during casting will ensure that the diameter is exactly the same. have greater flow resistance than those with short passages. In this invention, The long passages are made larger than the short ones so that the resulting flow resistance values are the same. Ru. Although it is possible to use this polishing original note as a machining method to obtain the dimensions, It is not part of this invention.

The effect of various orifice conditions on the polishing media flow ratio There may be some deviation from the intended flow ratio. For example, rough surfaces, edge radii, Orifice diameter and length etc. affect air, water and gasoline differently. results and The orifice is then quantified with a suitable test fluid prior to abrasive flow machining. The test fluid flow information and the initial abrasive media flow ratio are the polishing media flow to correspond to the targeted test fluid flow rate. Adjust the amount.

In the application of this specification, for orifices as small as 0.010 inches, It is desirable to use somewhat fine abrasive particles of 600 to 1200 mesh or less. stomach. This also provides better control over the extent and rate of removal from the workpiece. It is. and results in a finer surface lift than with coarser abrasives It is something. For large orifices, relatively large grains are more effective. , especially when large changes in flow rate are required. Especially silicone carver The use of hard abrasive materials such as Ido is recommended when large machining cycles are required. , is desirable in order to minimize changes in polishing performance. Use a softer abrasive Therefore, the polishing medium needs to be replaced frequently. In any case, replacing the polishing media Eating is required on a regular basis. Polished material collects in the media and eventually increases viscosity This is because a change occurs in the flow performance. This is proportional to the number of machined parts. Although it does not occur as much as it does, it is definitely a parameter worth noting. not present.

Keep adding new polishing media in small amounts and often so that the new media is mixed into the old media. The blending effect is used to ensure that the ingredients are evenly dispersed, and the mixture has a uniform consistency. It can be kept in this condition. This can be done manually or automatically.

impediment to implementation The fuel injection tip shown in FIG. 1 was obtained. 1 master spray tip through eight orifices at the same angle of ±3 degrees around the tip. , has an air flow of 0.375 cfm at 70 psig. Orifice size is 0 ．． 006 finch inner diameter. The orifice was created by electrical discharge machining with polishing flow machining. The value is 0.0060. In addition, a total of 500 spray tips are included in the master tip. It was drilled to a nominal 0.0060 inch diameter to resemble a drilled hole. 12 sprays Testing of the chip indicates a flow rate of 0.315 cfm±0.0 at 70 psig. It became 035cfm.

Holds the mask spray tip within a stationary tool, restricting flow to the inner passageway only, Attached to polished ridges. Abrasive flow processing equipment uses abrasive media, polymers (borosiloxane 1/10% by weight of 40 micron silicon carbide with I use a mixture of borosiloxane.

This device includes a beam, a measuring sensor and a sample sampled by a microprocessor. The microprocessor reads once every 0.1 seconds. The flow of the polishing medium through the master is A reference Vo for body and pressure was established. This value is the reference for the spray tip that follows. used as a value.

Each of the 500 spray tips is attached to a device, polished, and referenced. Achieved the value v0. Target value■. The average time to achieve 0 second spray was 7 seconds. The chip was removed, cleaned, and tested. Samples at 70 psig 0.375cfm minus 0.003. +0.002cfm air volume showed that.

X vertical l 50 turbine blades shaped as shown in Figure 4, with a span length of 3 inches and 1 ．． The 2-inch string version was investment cast. Each laser has a total of 21 6 orifices were drilled. 12 rows of orifices spaced the same distance apart along the span It has a diameter of approximately o, oos inches, and is polished to a diameter of 0.010 inches by milling. was made into In other testers, the master is 1836c at 7 spsig. There was an air volume of fm.

If any orifice other than one is plugged, the orifice will drop to 8 at 75 psig. ．． There was an air volume of 5 cfm. The remaining turbine blades are laser-cut by approximately 0.022 The same orifice with an inch diameter was drilled and attached to a polishing fed-batch device, and the As shown, attach it to the device and set the reference value ■. One feather that has been worked until it becomes When I removed it, cleaned it, and tested it at 75 psig, the air volume was 14.5 cfm. It showed ±0.05cfm.

Claims (17)

[Claims] 1. In a flow resistance control method in fluid orifice manufacturing, A. to the specified pressure determine the target flow resistance of the flowable abrasive media; B. During the dynamic flow resistance measurement of the orifice, the viscoelastic polishing medium at the predetermined pressure is pushing the body through the orifice, and C. While the dynamic flow resistance of the orifice is smaller than the target flow resistance, the push Continue pushing out, and when the dynamic flow resistance reaches the target resistance value, stop the pushing out. A flow resistance control method in fluid aperture manufacturing characterized by discontinuation. 2. The claim is characterized in that the target flow resistance is determined by a master structure. A flow resistance control method in manufacturing a fluid orifice according to claim 1 3. The targeted resistance is determined by the dynamic flow of the orifice in the master structure. While measuring resistance, a viscoelastic polishing medium is passed through the orifice to Claim 2, characterized in that the determination is made by extruding with pressure. Flow resistance control method in fluid orifice manufacturing. 4. Claims characterized in that said extrusion is generated by movement of a piston. A method for controlling flow resistance in manufacturing a fluid orifice as set forth in item 1 above. 5. The dynamic flow resistance is a function of the axial movement of the piston per unit time. For manufacturing a fluid orifice according to claim 4, which is characterized in that the fluid orifice is measured by Flow resistance control method. 6. Claim 5, wherein the function is defined by Vo=KDp/t. Flow resistance control method in fluid orifice manufacturing as described in . 7. Claim 6, wherein the k is defined by K=Ap/Ao. Flow resistance control method in fluid orifice manufacturing as described in . 8. Claim 1, characterized in that the unit time is set to be shorter than about 1 second. Flow resistance control method in fluid orifice manufacturing according to item 5. 9. Claim No. 1 characterized in that the unit time is set to 0.1 seconds or less. Flow resistance control method in fluid orifice manufacturing according to item 5. 10. An object having a flow measurement orifice, the object comprising a body and an orifice; The orifice has a constant flow resistance to the fluid at a predetermined pressure. The working flow resistance is defined as a function of the dynamic flow resistance of the abrasive processing medium. An object characterized by being 11. A flow resistance control method in fluid orifice manufacturing, the method comprising: A. Target flow of polishing media that is allowed to flow through the orifice at a given volumetric flow rate B. During orifice dynamic flow resistance measurement, the predetermined volumetric flow rate extruding a viscoelastic abrasive media through the orifice; C. While the dynamic flow resistance of the orifice is smaller than the target flow resistance, the push Continue pushing out, and when the dynamic flow resistance reaches the target resistance value, stop the pushing out. A flow resistance control method in fluid aperture manufacturing characterized by discontinuation. 12. The target flow resistance is determined by a master structure. A method for controlling flow resistance in manufacturing a fluid opening according to claim 11. 13. The target resistance is determined by the dynamic flow of the orifice in the master structure. While measuring the friction resistance, a viscoelastic abrasive media is passed through the orifice at the location. Claim 12, characterized in that it is determined by extruding at a constant volumetric flow rate. Flow resistance control method in fluid orifice manufacturing as described in . 14. The above-mentioned extrusion is caused by the movement of a piston. A method of controlling flow resistance in manufacturing a fluid orifice according to scope 11. 15. The dynamic flow resistance produces a constant volume displacement by the piston per unit time. Claim 1 characterized in that the measured pressure is measured as a function of the pressure required to produce the 4. A flow resistance control method in manufacturing a fluid orifice according to item 4. 16. Claims characterized in that the unit time is set to be smaller than about 1 second. 16. A flow resistance control method in manufacturing a fluid orifice as set forth in item 15. 17. Claims characterized in that the unit time is set to about 0.1 seconds or less. 16. A flow resistance control method in manufacturing a fluid orifice as set forth in item 15.