JPH05177546A - Polish feeding method with abrasive water jet - Google Patents

Abstract

PURPOSE:To keep always the accuracy of processing a work which is performed by spouting an abrasive water jet from a nozzle, by measuring the concentration of a sllury of polishing material following its path of being collected, and re- feeding it upon setting to a specified concentration. CONSTITUTION:To cut a work 9 by an abrasive water jet 11, a high pressure water is supplied from a high pressure water generating device 1 while a slurry 6' of polishing material is fed from a slurry tank 15' and spouted out of a nozzle 7. The water jet 11 having served the cutting work is received by a catcher tank 8 and returned to a tank 15' via a plurality of separative collectors 13, 14. The weight and volume of the slurry 6' are measured by a load cell 20 and a liquid level gauge 19, and on the basis of measurements the concentration of the slurry 6' is calculated by a control device 21. A hopper 17 is opened and shut under control in accordance with the difference between the concentration calculation and its set value, and new polishing material is additionally supplied to the tank 15'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The disclosed technology belongs to the technical field of performing cutting and the like with a jet of ultra-high pressure water jetted from a nozzle with a small diameter to metal machine parts and the like.

[0002]

2. Description of the Related Art As is well known, science and technology are largely responsible for the modern society that has developed remarkably, but mainly mechanical technology.

[0003] Therefore, as various mechanical appliances and equipment plants have complicated mechanical structures, many of them are composed of a combination of a plurality of parts. Therefore, of course,
The precise structure of each component has become extremely important, and therefore, the processes such as cutting, cutting, punching, and peeling of each component and the mold have become precise and extremely complicated.

Not only machine parts as products, but also machine tools used for molding and molding of these products are required to be complicated and fine, and these molds are required. ， Mechanical processing such as cutters and drills has been used for manufacturing processing of mechanical parts for a long time, but multiple steps such as primary processing and secondary processing are required from the viewpoint of mechanical roughness etc. In addition, since polishing processes are required, the number of processes is large, the work is complicated, the cost is high, and the improvement of efficiency is hindered. And other new technologies have been developed.

However, these techniques also have the drawback that the material change of the base material, residual strain, etc. occur, and in addition,
There are inconveniences that the devices are remarkably complicated, a large space is required, and management control is complicated.

On the other hand, a processing technology by so-called water jet, which utilizes the kinetic energy of jetting ultra-high pressure water from a small diameter nozzle at ultra-high speed, has been developed. Needless to say, a technology has been developed that can perform processing such as cutting, cutting, and peeling even on workpieces made of metal, etc., and further various researches and improvements have been made to the high pressure water and fine powder granules such as garnet sand. Abrasive water jet, which mixes abrasives and is ejected integrally, has also been developed and put into practical use in various machine manufacturing industries such as the automobile industry.

That is, as shown in FIG. 3, the high pressure water 2 from the predetermined high pressure water generator 1 is fed to the mixing chamber 4 of the nozzle head 3, and the abrasive passage 5 is fed to the mixing chamber 4. The fine powdery abrasive material 6 such as garnet sand supplied from the is mixed by negative pressure suction or the like, uniformly dispersed and stirred, and the nozzle 7 to the catcher tank 8
A predetermined work is performed by being ejected as an abrasive water jet 11 to the processing portion 10 of the predetermined work 9 facing the above.

The catcher tank 8 is designed to absorb the impact of an ultra-high-speed abrasive water jet with an impact absorbing material such as a steel ball so that the polishing material 6 is deposited.

[0009]

However, in the processing of the work 9 by such an abrasive water jet, since the grain size distribution of the abrasive 6 is required to be severe, it is extremely expensive in terms of material and therefore, The one-pass type disposable type has the disadvantage of being reproducible in terms of product cost, and discarding the abrasive 6 that precipitates in the catcher tank 8 must be prevented from the viewpoint of pollution problems and environmental pollution. In order to cope with the above problem, the abrasive material 6 settling in the catcher tank 8 is collected and reused by forming a circulation path to the abrasive material feeding passage 5 connected to the catcher tank 6 and the mixing chamber 4 of the nozzle head 3. The material feeding method has come to be adopted,
For example, as shown in FIG. 4, a loop-shaped circulation path 12 is formed between the catcher tank 8 and the mixing chamber 4, and a predetermined separation device 1 such as a magnet type screen is formed.
3, a sorting device 14, a slurry tank 15 and the like are installed in series, and are circulated by pumps 16, 16 ', 16''for recovery and reuse.

By the way, as described above, the abrasive water jet has a large processing capability by applying high energy through the abrasive material such as garnet sand mixed therein as described above, and moreover, a fine processing according to the design. However, the concentration of the abrasive slurry pressure-fed from the mixing chamber 3 to the nozzle 7 decreases due to the abrasion of microscopic particles of the abrasive during construction, and the processing accuracy gradually increases. Inevitable decline.

Therefore, although the particle size distribution of the abrasive circulated by the separating device 13 and the collecting device 14 is readjusted, and the amount of depletion is supplied by the hopper 17 to the slurry tank 15, Although qualitatively stable circulation is performed, the concentration of the abrasive slurry that is collected and circulated is unstable quantitatively, and as a result, the particle size distribution of the abrasive ejected from the nozzle 7 changes and the workpiece is changed. There was a negative point that the roughness such as the cut surface of the cutting process of 9 could not be performed as designed, and the product accuracy varied.

[0012]

OBJECT OF THE INVENTION The object of the invention of this application is to solve the problem of unstable concentration of the circulating abrasive slurry in the abrasive water jet of the abrasive circulating and recycling system based on the above-mentioned prior art. , Processing technology in the machine manufacturing industry by accurately measuring the concentration of the abrasive slurry in the circulation path without taking complicated steps and ensuring the circulation of the abrasive slurry to the nozzle head at a stable concentration The purpose of the present invention is to provide an excellent abrasive water feeding method for abrasive water jets, which benefits the field of use.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the structure of the invention of this application, which has been made in line with the above-mentioned object and has the above-mentioned claims as its gist, is designed for cutting and cutting metal machine parts. When processing is performed by an abrasive water jet, high pressure water from a predetermined high pressure water generator is supplied to the mixing chamber of the nozzle head, and an abrasive having a predetermined particle size distribution such as garnet sand is sent to the mixing chamber. The abrasive slurry is fed, mixed and stirred to form an abrasive slurry, which is ejected as a jet from the workpiece facing the catcher tank from the nozzle to perform predetermined processing. The abrasive slurry used for the processing is stored in the catcher tank. And the impact energy was absorbed, and the abrasive material settled and was worn by the separation / recovery device such as a magnet type screen through the circulation path. Abrasives and other mixed dusts are removed, and only abrasives with a predetermined particle size distribution are controlled and fed to a slurry tank, agitated by a mixer or the like to a uniform dispersion state, and the slurry The weight of the tank is measured with a load cell, etc., the volume of the slurry is measured with a level gauge, etc., the concentration is measured with a predetermined measuring device, or the light transmittance is measured. This is a technical measure that allows a new abrasive material to be replenished from the hopper so as to be constantly maintained at a set concentration and circulated and supplied to the mixing chamber for reuse.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the invention of this application is shown in FIGS.
The explanation is based on the following.

It should be noted that the same aspects as those in FIG. 3 and subsequent figures will be described using the same reference numerals.

The illustrated embodiment is a mode in which the work of fine parts is cut by a wet type abrasive water jet, and the abrasive is recycled and fed by a circulation recovery system, and is shown in FIG. In the embodiment, the mixing chamber 4 of the nozzle head 3 faces the high pressure water 2 from the predetermined high pressure water generator 1 and the abrasive material feeding passage 5 such as garnet sand which is circulated and reused. The nozzle 7 is directed to the cut portion of the work 9 exposed to the catcher tank 8 as in the conventional mode.

A circulation path 12 is formed in the abrasive material feed passage 5 from the catcher tank 8 to form the pump 1
6, 16 and the like are separated and collected by a magnetic screen or the like for the abrasive slurry 13, 14 and a slurry tank 15 'are connected in series, and the slurry tank 15' is provided for the abrasive to be worn. A new abrasive material supply hopper 17 is also installed.

Further, the slurry tank 15 'is provided with a mixer 18 for preventing suspended sedimentation of the recovered abrasive material, and an appropriate liquid level gauge 19 (known as the liquid level gauge 1).
Reference numeral 9 is a mechanical type such as a contact type. ) Is further provided, and the slurry tank 15 ′ is further provided with a load cell 20 for measuring the total weight together with the slurry 6 ′. The mixer 18, the liquid level gauge 19, and the load cell 20 are electrically connected to a predetermined control device 21. It is connected.

This is because there is no device for measuring the concentration of the abrasive slurry directly at the time of the invention of this application.

Further, the slurry tank 15 'of the circulation path 12
Opening / closing valves 23 and 23 'are provided on the inlet side and the outlet side of and electrically connected to the controller 21, and 22 is an abnormal concentration warning lamp, which is also electrically connected to the controller 21. There is.

In the abrasive water jet plant having the above structure, when water jet cutting is performed on the work 9, the high pressure water from the high pressure water generator 1 is supplied, and the abrasive slurry tank 15 'and the pump 16 are used. The abrasive slurry 6'having a set concentration is supplied from the supply passage 5 to the mixing chamber 4 of the nozzle head 3 and mixed and stirred in a uniformly dispersed state, and an abrasive water jet 11 is ejected from the nozzle 7 toward the work 9. Then, the predetermined cutting is performed.

The abrasive water jet 11 that has been used for cutting has its jet energy absorbed by steel balls or the like in the catcher tank 8, and the abrasive material settles down and the pump 16 circulates the circulation path 12
In the recovery process, the separation and recovery devices 13 and 14 such as a magnetic screen remove the foreign substances that are worn or mixed in the cutting process and are effectively reused. It is fed to the abrasive slurry tank 15 '.

Then, the total weight of the abrasive slurry in the slurry tank 15 'and the weight of the tank itself are both measured by the load cell 20 and the detection signal thereof is input to the control device 21. The level of the abrasive slurry 6'of 15 'is measured by the liquid level gauge 19 and input to the controller 21.

Therefore, since the tare of the slurry tank 15 'is known in advance in the controller 21, the weight of the abrasive slurry 6'can be measured by performing a predetermined calculation.

Since the sectional area of the slurry tank 15 'is also known in advance, the volume of the abrasive slurry 6'is also measured by the level measured by the liquid level gauge 19, and therefore the mixer 18 is used as the abrasive slurry 6'. As long as it is not uniformly dispersed and suspended and settled, its concentration is immediately measured and compared with the designed concentration in the abrasive water jet.

As described above, in the abrasive water jet, since the abrasive material used for the cutting process actually wears, the separating and collecting device 13,
Since the abrasive material unsuitable for reuse is removed at 14, the concentration decreases as long as the mixer 18 is dispersing and stirring.

Therefore, for the abrasive slurry having a reduced concentration with respect to the set concentration, a new abrasive is opened and closed by a control signal from the control device 21 of the damper from the hopper 17 so that the new abrasive has a slurry concentration of 15 '. Since it is supplied and dispersed and mixed by the mixer 18, it is automatically controlled and managed so as to have a set concentration automatically, and is cyclically supplied to the mixing chamber 4 of the nozzle head 3 via the pump 16. To go.

The starting and stopping of the abrasive water jet is performed by controlling the opening / closing valve 23 by the controller 21 for supplying the abrasive slurry to the mixing chamber 4 for the tank.

In this way, the cutting of the work 9 by the abrasive water jet is always stably carried out by the cyclic supply of the abrasive with the abrasive slurry of the same concentration, and the product accuracy is guaranteed as designed. You can

Therefore, the abrasives in the abrasive water jet 11 ejected from the nozzles always have the same particle size distribution, and the processing accuracy is always guaranteed.

Next, in the embodiment shown in FIG. 2, a set number of bulkheads 24 are provided in the abrasive slurry tank 15 'so that the slurry concentration in the final-stage slurry tank main body becomes more stable. Moreover, in this embodiment, the concentration of the abrasive slurry 6'set to the set concentration by the mixer 18 is measured by the liquid level meter 19 'of the light transmission type. Is unchanged.

The embodiment of the invention of this application is not limited to the above-mentioned embodiments, and for example, the concentration of the abrasive slurry is measured by a particle size distribution measuring device or an electric resistance measuring device. Various modes such as the above can be adopted.

As a similar example, it goes without saying that the measurement result in the control device can be automatically recorded and used as a reference for other modes.

Further, in the case where the concentration is over, it is also possible to adopt a method of appropriately supplying water.

[0035]

As described above, according to the invention of this application, it is basically recovered by the circulation and reuse system of the abrasive material such as garnet sand used in the abrasive water jet used in the molding of metal machine parts. When circulating the abrasive material in the form of abrasive slurry to the mixing chamber of the nozzle head, measure the concentration of the abrasive slurry in the abrasive slurry tank through the circulation path so that the concentration reaches the set value. By doing so, the abrasive material concentration of the abrasive water jet ejected onto the work is made constant, so that the machining accuracy of the work is always kept the same, and the reliability of the product is also excellent. The effect is played.

Further, since the concentration of the abrasive slurry is maintained at the set concentration, even if the abrasive water jet is started and stopped, it does not cause clogging or the like at the time of start-up, and therefore, it has the desired design. An excellent effect is achieved that a break water jet can be performed.

Since the used abrasives are cyclically collected and reused, it leads to cost reduction, and since it is not necessary to dispose of wastes, pollution problems and environmental problems are avoided. It also has the effect of not connecting.

[Brief description of drawings]

FIG. 1 is an overall schematic diagram of an embodiment of the invention of this application.

FIG. 2 is a partial schematic view of another embodiment.

FIG. 3 is a schematic partial cross-sectional side view of the abrasive water jet processing.

FIG. 4 is a schematic view of an abrasive jet circulating and collecting system according to the prior art.

[Explanation of symbols]

 3 Nozzle head 4 Mixing chamber 7 Nozzle 8 Catcher tank 6 Abrasive material 12 Recovery circulation path 6'Abrasive material slurry 19, 19 'Concentration measuring device

Claims (3)

[Claims] 1. An abrasive material feeding method for an abrasive water jet, wherein the abrasive material is collected, circulated and reused from a catcher tank with a nozzle facing the mixing chamber of the nozzle head, and the abrasive material is collected into the mixing chamber. An abrasive material feeding method for an abrasive water jet, characterized in that the concentration of the abrasive material slurry is measured in a circulation path and set to a preset concentration and then fed to the mixing chamber. 2. The abrasive water feeding method for an abrasive water jet according to claim 1, wherein the concentration is measured by measuring the weight of the slurry tank and the volume of the slurry. 3. The method according to claim 1, wherein the concentration is measured by the light transmittance of the slurry.
The abrasive water supply method for the abrasive water jet as described in the item.