JP2008137092A - Fluid polishing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To polish minute holes of a fuel injection nozzle by a fluid for polishing accurately and prevent wear of a member of a polishing device and replace abrasive grains for polishing easily. <P>SOLUTION: This fluid polishing device for the minute hole by use of a low viscosity liquid 6 and polishing abrasive grains 5 is provided with: a low viscosity liquid pressure flow passage 11 for feeding the pressurized low viscosity liquid 6 into the minute holes 2 and polishing abrasive grain pressurizing confluent means (a cylinder 13; a polishing abrasive grain supply passage 14, and a check valve 15) for joining the polishing abrasive grains 5 with the low viscosity liquid 6 in the low viscosity liquid pressure flow passage 11 by pressurizing the polishing abrasive grains 5. The polishing abrasive grains can be uniformly dispersed in the low viscosity liquid without using additive such as dispersing agent and viscosity of the polishing fluid is properly controlled to polish accurately and easily. The polishing abrasive grains are mixed in only a partial section to reduce area of a worn section as much as possible. Any desired amount of polishing abrasive grains is supplied securely and simply. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fluid polishing apparatus used for polishing fine holes such as an injector for fuel injection of an engine.

In order to refine the spray for improving the exhaust gas performance at the nozzle of the fuel injection nozzle of the engine, a large flow rate can be obtained by reducing the resistance of the fluid while being a fine hole with a diameter of 0.2 mm or less Is required. Also, precisely controlled fine holes (orifices) are used for precision hydraulic control valves and the like.
Therefore, a method is adopted in which the abrasive grains are mixed with the fluid and pumped from the inside of the nozzle to round the corners of the fine holes to increase the flow rate (increase the flow coefficient) without changing the hole diameter. ing. The variation in the flow rate characteristic from the fine hole of the working fluid (fuel or hydraulic fluid) has a great influence on the engine performance and the hydraulic pressure characteristic, so it is necessary to adjust the flow rate accurately.
Previously, it was mixed with clay-like high-viscosity fluid, but for efficiency, a low-viscosity fluid close to the viscosity of the fluid used was used, and processing was performed while monitoring the flow rate to achieve the required flow rate. It can be reached quickly (see, for example, Patent Documents 1 and 2).
In addition, a method has been proposed in which a blasting material is mixed with pressurized air to polish the nozzle mouth (see Patent Document 3). However, in dry polishing, the frictional force is too great and the blasting material is clogged into micro holes. There is a problem that it is easy. Further, in polishing using pressurized air, it is difficult to adjust the polishing of the micropores while accurately managing the flow rate.

In the methods disclosed in Patent Documents 1 and 2, polishing is performed by supplying a slurry obtained by mixing abrasive grains to a low-viscosity fluid while controlling the flow rate and flow rate while pressing the fine holes. One example will be described with reference to FIG.
In this example, hydraulic pressurization is performed using two cylinders.
Abrasive grains (alumina, silicon carbide, CBN, diamond, etc.) are uniformly mixed (slurry) into a low-viscosity fluid (water, silicon oil, vegetable oil, mineral oil, synthetic oil, etc.) as a polishing medium, and then a slurry tank. 20 stored. In addition, since the abrasive grains are heavier than the fluid, a treatment is performed in which a dispersing agent or the like is mixed and does not precipitate. The temperature of the slurry in the slurry tank 20 is adjusted by a slurry temperature controller 21.

  When the slurry is directly pressurized by the pump, it is worn by the friction of the abrasive grains. Therefore, in the hydraulic unit 30, the hydraulic cylinders 33, 33 are controlled by the cylinder operation valves 31. And pressure is transmitted to the slurry cylinders 22 and 22. The displacement amount of the cylinder is detected by a cylinder displacement meter 34. The pressure control of the servo valve 32 is performed by feeding back the signal from the slurry pressure sensor 28. It is also possible to employ an electric cylinder instead of the hydraulic cylinder.

The direction of the slurry whose temperature is controlled by the slurry temperature controller 21 is controlled by the slurry valves 23 and 24, is pushed out from the slurry cylinder 22, and is supplied to the nozzle 29, which is a workpiece, through the slurry filter 26. At this time, the slurry flow rate is measured by the flow meter 25, and the temperature of the slurry is measured by the temperature controller sensor 27.
By passing the slurry from the inside of the nozzle 29 at a high pressure, the abrasive grains remove the edge part and the inner diameter of the nozzle nozzle little by little.
The characteristics of the slurry as a fluid are grasped by comparing with the fluid (fuel or hydraulic oil) actually used, and the increase in the slurry flow rate is monitored in real time using the slurry flow meter 25 or the cylinder displacement meter 34, Complete machining at any set flow rate.
The polishing quality of the work material edge, the flow rate variation after completion, and the processing time are greatly affected by the uniformity of the viscosity of the abrasive grains and the media.
Japanese National Patent Publication No. 11-510437 JP 2005-177916 A JP 2003-28032 A

However, if the abrasive grains are simply mixed in the fluid as described above, the abrasive grains precipitate in a short time. In order to uniformly disperse the abrasive grains in the slurry, it is necessary to mix an additive for improving dispersibility such as a dispersant into the fluid. However, the change in viscosity and the variation in viscosity due to the additive greatly affect the processing characteristics. Therefore, it is necessary to accurately control this, and the work load increases. Slurry is pumped by a cylinder, but hard abrasive grains wear components such as cylinders, valves, flow meters, etc., so their life is shortened.
Furthermore, there are appropriate values for the packing density and size of the abrasive grains in the slurry, depending on the shape of the fine holes (diameter and length). However, since the abrasive grains are dispersed throughout the slurry, it is necessary to replace the entire slurry for the change, but it is difficult to completely remove the small abrasive grains, and different abrasive grains are mixed after the replacement. There's a problem.

  The present invention has been made against the background of the above circumstances, and improves the dispersibility of abrasive grains without the need for a dispersant, and reduces component wear and improves the certainty and simplicity of abrasive grain replacement. An object of the present invention is to provide a fluid polishing apparatus.

  That is, among the fluid polishing apparatuses according to the present invention, the invention according to claim 1 is a microporous fluid polishing apparatus using a low-viscosity liquid and abrasive grains. A low-viscosity liquid pressure channel that is fed to the low-viscosity liquid pressure channel, and abrasive-abrasive pressure merging means that pressurizes and merges the abrasive particles with the low-viscosity liquid in the low-viscosity liquid pressure channel. .

  A fluid polishing apparatus according to a second aspect of the invention is the invention according to the first aspect, wherein the polishing abrasive pressure confluence means pumps the abrasive grains deposited in the low-viscosity liquid by pressurizing the low-viscosity liquid. It is a pressure feeding device.

  According to a third aspect of the present invention, there is provided the fluid polishing apparatus according to the first or second aspect, wherein the polishing abrasive pressure pressurizing / merging means is a mono pump or includes a mono pump.

  A fluid polishing apparatus according to a fourth aspect of the invention is characterized in that, in the invention according to any one of the first to third aspects, the low-viscosity liquid fluid is a liquid fluid that is actually used in micropores.

  The invention of a fluid polishing apparatus according to claim 5 is the invention according to any one of claims 1 to 4, wherein the low-viscosity liquid pressure flow path and the abrasive abrasive pressure confluence are formed upstream of the confluence. A check valve is provided in each merging channel of the means.

  According to the present invention, in the low-viscosity liquid pressure channel, the abrasive grains are joined to the pressurized low-viscosity liquid while being pressurized, so that the abrasive grains are dispersed well after the joining point. A fluid is obtained. The polishing fluid is fed into the micropores under pressure and used for polishing. Since the main low-viscosity liquid and the abrasive grains are mixed at the joining point, the type of liquid and the type of abrasive grains can be easily changed on the upstream side of each. Further, since the abrasive grains flow mainly after the above-mentioned joining point, it is possible to avoid wear of various members and minimize damage to the members. Pressurization of the low-viscosity fluid does not include abrasive grains, and therefore can be performed using hydraulic pressure, an electric cylinder, or the like without causing wear.

  The abrasive grain pressurizing / merging means may be any means capable of pressurizing and supplying the abrasive grains to the low-viscosity liquid pressure channel, for example, a state in which the abrasive grains are deposited by adding a small amount of low-viscosity liquid. And may be supplied and joined by a pressure feeding device such as a hydraulic or electric cylinder. The deposited abrasive grains are restrained from flowing to reduce wear of the cylinder and the like. Further, as a polishing abrasive pressure confluence means, a generally known MONO pump can be used. By adding and supplying abrasive grains and a small amount of low-viscosity liquid to the MONO pump, the abrasive grains can be mixed in a low-viscosity liquid pressure channel in a pressurized state. In addition, the above-described pumping device and the mono pump are combined, for example, a mono pump is arranged on the downstream side of the pumping device, and the abrasive grains are dispersed in a small amount of the low-viscosity liquid and joined to the pressurized low-viscosity liquid. May be.

  In the low-viscosity liquid pressure channel, after the abrasive grains are mixed, the low-viscosity liquid in which the abrasive grains are dispersed in the micropores may be supplied immediately, and the mixed abrasive grains are contained in the low-viscosity liquid. A predetermined length of the abrasive grain mixing section may be secured so as to disperse evenly. The distance of the section can be appropriately set based on the dispersion state and pressure of the abrasive grains. In addition, a stirring device such as a fan or a screw conveyor can be provided in the abrasive grain mixing section in order to promote uniform dispersion of the abrasive grains.

As described above, the fluid polishing apparatus according to the present invention is a microporous fluid polishing apparatus that uses a low-viscosity liquid and abrasive grains, and is a low-pressure liquid feeder that supplies the pressurized low-viscosity liquid to the micropores. Since there are provided a viscous liquid pressure flow path and polishing abrasive pressure confluence means for pressurizing and joining the abrasive grains to the low viscosity liquid in the low viscosity liquid pressure flow path, an additive such as a dispersant is used. In addition, the abrasive grains can be uniformly dispersed in the low-viscosity liquid. As a result, the characteristics of the fluid are equivalent to the fluid used alone, the variation in fluid viscosity is reduced, and accurate polishing can be easily performed. Furthermore, the fluid (fuel) actually used can be used as it is as the fluid for the polishing apparatus, and the performance as the fluid becomes the same, so that the performance can be stabilized.
Further, since abrasive grains are not mixed in the hydraulic pressure supply cylinder or the like, it is possible to prevent wear of the cylinder and the valve. In addition, there are few parts to be cleaned at the time of polishing abrasive grain replacement, and there is an effect that it is possible to reliably and easily supply arbitrary polishing abrasive grains and amount that can prevent mixing of different kinds of abrasive grains.

Below, one Embodiment of this invention is described based on FIGS. 1-3.
The object to be polished is the microhole 2 of the injection hole of the fuel injection nozzle 1 for a diesel engine shown in FIG. 1, and the chamfering of the corners of the microhole 2 is performed by fluid polishing.
As shown in FIG. 2, the fluid polishing apparatus 10 includes a low-viscosity liquid pressurizing channel 11 that supplies a clean low-viscosity liquid pressurized by a hydraulic cylinder or a pump (not shown) to the nozzle 1. . As the low-viscosity liquid, it is preferable to use light oil that is actually used in the fuel injection nozzle 1.
A check valve 12 is interposed in the low-viscosity liquid pressurizing flow path 11, and a polishing abrasive supply path 14 is joined downstream of the check valve 12. The upstream side of the abrasive grain supply path 14 is connected to a cylinder (hydraulic or electric) 13 as a pressure feeding device via a check valve 15. The cylinder 13, the abrasive grain supply path 14, and the check valve 15 constitute the abrasive grain pressurizing and merging means of the present invention.

The low-viscosity liquid pressurizing flow path 11 after joining is connected to the fuel introduction part 1a of the fuel injection nozzle 1 to be polished via a Coriolis flow meter 16. As the Coriolis type flow meter 16, a known one can be used as shown in FIG.
A drainage path 17 is connected to the outlet side of the microhole 2 of the fuel injection nozzle 1, and the drainage path 17 is connected to a filter or a centrifuge 18, and is connected to a liquid passing side of the filter or centrifuge 18. A drainage path 17a is connected, and an abrasive reflux path 17b is connected to the filtrate side. The drainage path 17 a is connected to the liquid storage tank 19, and the abrasive grain reflux path 17 b is connected to the cylinder 13.

Next, the operation of the fluid polishing apparatus 10 will be described.
The abrasive grains 5 of appropriate materials are stored in the cylinder 13 by being precipitated in the low-viscosity liquid 6a, and are always supplied in the direction of gravity. In the cylinder 13, the abrasive grains 5 are pressurized through the supernatant low-viscosity liquid 6 a. The abrasive grains 5 are supplied to the low-viscosity liquid pressurizing flow path 11 through the abrasive grain supply path 14 while being pressurized by the cylinder 13. At this time, backflow is prevented by the check valve 15 provided in the abrasive grain supply path 14. The low-viscosity liquid 6a is preferably made of the same material as the pressurized low-viscosity liquid 6 described later.

  On the other hand, in the low-viscosity liquid pressurizing flow path 11, a clean low-viscosity liquid 6 pressurized by a hydraulic cylinder or a pump is fed, and the low-viscosity liquid 6 is joined at the junction with the abrasive grain supply path 14 described above. The abrasive grains 5 are mixed with the above. As a result, the abrasive grains 5 are quickly dispersed in the pressurized low viscosity liquid 6. The low-viscosity liquid 6 containing the abrasive grains 5 is fed to the downstream side as a polishing fluid through the low-viscosity liquid pressurizing channel 11 and supplied to the fuel injection nozzle 1 while the flow rate is measured by the Coriolis flow meter 16. The After the polishing fluid supplied to the fuel injection nozzle 1 is introduced into the fuel introduction part 1a, the fine hole 2 is also polished by passing through the fine hole 2 while chamfering the corners of the fine hole two corners.

The polished polishing fluid passes through the drainage path 17 to the filter or the centrifugal separator 18 where it is filtered and only the low-viscosity liquid is stored in the liquid storage tank 19 and then the low-viscosity liquid. It is returned to the hydraulic cylinder and pump that pressurizes the pressure. On the other hand, the abrasive grains 5 which are the filtrate filtered by the filter or the centrifugal separator 18 are supplied again to the cylinder 13 through the abrasive reflux path 17b. As described above, the polishing fluid used for polishing can be separated into a low-viscosity liquid and abrasive grains by a filter or the like and reused.
When the flow rate measured by the Coriolis flow meter 16 reaches a set flow rate, the insertion of the low-viscosity liquid by the low-viscosity liquid pressurizing flow path 11 and the supply of the abrasive grains by the cylinder 13 are stopped to finish the polishing. . According to the above, polishing can be performed with a polishing fluid that does not contain a dispersant, and unevenness and inaccuracy of polishing due to variations in the viscosity of the polishing fluid can be prevented.

  Further, when changing the type of abrasive grains by changing the polishing target, the abrasive grains accommodated in the cylinder 13 are replaced, and the low-viscosity liquid pressurizing channel 11 is washed and replaced on the downstream side of the joining point. Can be done. There is no need to clean, replace, etc. the low-viscosity liquid pressurizing flow path 11 on the upstream side of the junction. Further, the flow of the abrasive grains greatly occurs on the downstream side of the merging point and wear of the flow path. Therefore, it is sufficient to perform maintenance such as appropriately replacing the low-viscosity liquid pressurizing channel 11 on the downstream side of the merging point. It is possible to avoid wear of the flow path and the pumping device on the upstream side of the point.

Furthermore, in the above-described embodiment, as one of the methods of pumping at a high pressure while maintaining the dispersed state of the abrasive grains on the downstream side of the joining point in the low-viscosity liquid pressurizing flow path, a fan or the like is provided on the downstream side of the joining point. The stirring device can be provided.
Moreover, in the said embodiment, although pumping apparatuses, such as a cylinder, were used as an abrasive grain pressurization joining means, it can change to this and can use the MONO pump 40 etc. which are shown in FIG.
The MONO pump 40 is known, and an eccentric male screw-shaped rotor 44 is arranged in a female screw-shaped stator 43, and fluid can be pumped in the stator 43 while rotating the rotor 44.

A small amount of low-viscosity fluid and abrasive grains are accommodated in the supply chamber 42 through the supply port 41 and then introduced into the stator 43 and sent. By being pumped by this MONO pump 40, the low-viscosity liquid and the abrasive grains are sent to the downstream side in an evenly mixed state and merged with the low-viscosity liquid pressurized at the merging point.
This MONO pump can also be used in combination with the cylinder 13 and is provided in the abrasive grain supply path downstream of the cylinder 13 to pressurize while mixing a small amount of low-viscosity liquid and abrasive grains evenly. It can also be made to merge with the low-viscosity liquid pressurization flow path 11.

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to the content of the said embodiment, In the range which does not deviate from the scope of the present invention, an appropriate change is possible. .

It is sectional drawing which shows the fuel-injection nozzle used as the grinding | polishing object of the fluid grinding | polishing apparatus of this invention. 1 is an overall view showing an embodiment of a fluid polishing apparatus of the present invention. Similarly, it is sectional drawing which shows the structure of the MONO pump used for one Embodiment of a fluid polishing apparatus. It is a general view which shows the structure of the conventional fluid polishing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel injection nozzle 2 Micro hole 5 Polishing abrasive grain 6 Low viscosity liquid 10 Fluid polishing apparatus 11 Low viscosity liquid pressurization flow path 12 Check valve 13 Cylinder 15 Check valve 16 Coriolis type flow meter

Claims (5)

In a microporous fluid polishing apparatus using a low-viscosity liquid and abrasive grains,
A low-viscosity liquid pressure channel that feeds the pressurized low-viscosity liquid to the micropores, and an abrasive particle that presses and joins the abrasive particles to the low-viscosity liquid in the low-viscosity liquid pressure channel A fluid polishing apparatus comprising pressure joining means.   2. The fluid polishing apparatus according to claim 1, wherein the polishing abrasive pressure confluence means is a pumping device that pumps the abrasive grains deposited in the low viscosity liquid by pressurizing the low viscosity liquid.   3. The fluid polishing apparatus according to claim 1, wherein the polishing abrasive pressure confluence means is a Mono pump or includes a Mono pump. 4.   The fluid polishing apparatus according to claim 1, wherein the low-viscosity liquid fluid is a liquid fluid that is actually used in micropores.   5. The check valve according to claim 1, wherein a check valve is provided on each of the low-viscosity liquid pressure channel and the merging channel of the abrasive abrasive pressure merging unit on the upstream side of the merging point. The fluid polishing apparatus according to any one of the above.

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