JPH06126631A - Rust preventing method of abradant in high speed abrasive fluid jet - Google Patents

Abstract

PURPOSE:To contribute to reuse of an abrasive and an improvement in work environment as rust prevention is effectively performed to the abrasive by adding a rust inhibitor, having an anticorrosive function for the fluid abrasive, in either process, in a process by means of a high-speed abrasive fluid jet to which the abrasive in added. CONSTITUTION:Abrasives out of a tank 5 are added to a jet stream in a nozzle, while a formed abrasive water jet is sprayed onto nozzle water W and thereby working takes place, therefore spent abrasives are recovered in a slurry form, they are recovered, selected, dewatered and dried up in a recycle unit and then refed to an inner part of the abrasive tank 5. In suchlike system, a rust inhibitor with a granular rust preventive function is additively fed to three spots of X1 to X3 by a pump from an additive storage tank 6. With this constitution, the extent of reuse life in the abrasive is prolonged and, what is more, operation can be done stably without entailing any supply instability due to rust gathering in the abrasive and any drop in working capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed polishing fluid jet in which an abrasive is added to a high-speed jet stream, the abrasive is conveyed by the high-speed jet stream, and collides with a base material to perform processing such as cutting and cutting. Regarding processing.

[0002]

2. Description of the Related Art Such high-speed polishing fluid jet machining, so-called abrasive water jet machining itself, is disclosed in JP-A-63-501489 and US Pat. No. 4,648.
As disclosed in Japanese Patent No. 215, the energy concentration of the abrasive ejected together with the jet flow from the nozzle is extremely high, and it is excellent for various materials such as metal, stone, glass and ceramics, members, etc. Has cutting and cutting ability.

In the field of conventional high-speed polishing fluid jet machining, in the case where the work piece is steel that easily rusts, an inhibitor may be added to prevent rusting of the work piece.
In addition, it has been reported that adding a small amount of polymer is effective for improving the convergence of high-speed fluid jets, cutting, and cutting ability. Furthermore, for preventing sedimentation of abrasives and improving transportability, polymers and surfactants There is also a report that the addition is effective.

The high-speed polishing fluid jet machining method uses a small operating machine such as a robot which has a high energy concentration and a high cutting efficiency, has no thermal effect on the material, does not generate dust, has a small reaction force, and has a small reaction force. Taking advantage of such features, attempts have been made to use it for grinding the surface of materials such as steel slabs.

When such a high-speed polishing fluid jet machining method is used for partial grinding of a steel slab, a large grinding area is required and a large number of grinding nozzles must be used. The target is the use of iron-based abrasives that have excellent crush resistance and high processing capacity.

Further, also in a general water jet processing system having a relatively small capacity, metal-based abrasive grains containing iron are considered to be promising from the viewpoint of running cost reduction and resource recycling.

However, in this case, as the abrasive grains, alumina,
As compared with the case of using garnet sand or silica sand, the iron powder of the abrasive grains is more likely to rust, and thus there are various problems such as problems in terms of work environment or the recyclability of the abrasive grains.

[0008]

However, in high-speed polishing fluid jet machining, a high-pressure water stream is generally used as a carrier fluid for abrasives, and therefore abrasives such as iron-based abrasives that easily rust. When used, the abrasive grains themselves rust due to the carrier water. This rusting of abrasive grains is not preferable from the viewpoint of reuse of abrasive grains, and especially when applying high-speed polishing fluid jet machining to surface grinding using a large amount of abrasive grains, the biggest problem to be solved in systematization This is an important issue from the standpoint of establishing the usage cycle of different abrasive grains.

An object of the present invention is to provide an effective means for preventing rusting of abrasive grains during high speed polishing fluid jet processing.

[0010]

According to the present invention, a process of pressurizing a carrier fluid, a process of adding an abrasive to a high-pressure fluid jet stream, and a process of recovering an abrasive contained in a fluid after processing, if necessary. , In the processing method by the high-speed polishing fluid jet in which the polishing material is added to the high-pressure fluid jet flow with the reuse process,
It is characterized in that a rust preventive agent having a function of preventing corrosion of the fluid abrasive is added in at least one of the above processes.

As such a rust preventive agent, an oxidation type inhibitor, a precipitation type inhibitor, an adsorption type inhibitor or the like can be used depending on the application, environment (working fluid, temperature, dissolved oxygen or chloride concentration, etc.), abrasives and the like. However, when general tap water is used as the working fluid and cast iron or cast steel-based abrasive grains are used as the abrasive, for example, a polymerized phosphate system or a polymerized silicate system is effective.

In the above case, the addition amount is 1 to 50 p.
About pm is sufficient.

In addition, upon addition, addition to a low-pressure water pump or the like in the process of increasing the pressure of the carrier fluid, recovery of abrasive grains after leaving the nozzle, addition in a reusable system, or addition of an abrasive Means such as addition to the nozzle portion or abrasive tank in the process can be adopted.

[0014]

[Function] Since the additive has a rust preventive effect on the abrasive in a very small amount, it prevents the abrasive from rusting without lowering the processing ability of the abrasive by the high speed jet stream.

[0015]

1 is a diagram showing an embodiment of the present invention as a system.

In the figure, reference numeral 1 is an abrasive water jet nozzle, and water pressurized from a low pressure water pump 2 by a pressure booster 3 is supplied through an accumulator 4. Further, 5 is an abrasive tank, and the abrasive from the tank 5 is added to the jet flow in the nozzle 1,
The formed abrasive water jet is nozzle 1
Is jetted onto the work W and processed. In such a processing system, on the lower surface of the work W, the used abrasive is collected together with the carrier water in the form of slurry, collected, sorted, dehydrated and dried in the recycler and re-supplied into the abrasive tank 5. A recovery system has been formed.

In such a system, a portion indicated by X indicates a portion suitable for adding an additive having an anticorrosive function for abrasive grains, and the additive is supplied from the additive storage tank 6 by a pump.

X ₁ represents the addition position in the low-pressure water pump 2, X ₂ represents the addition position in which the suction force is used when adding the abrasive to the high-pressure jet stream, and X ₃ represents the recovery of the abrasive grains. The position of addition to the system is shown, and a system in which these are arbitrarily combined can be adopted.

Addition position X in the low pressure water pump 2
₁ and the addition at the addition position X ₃ to the abrasive grain recovery system are methods that have the least effect on the abrasive water jet processing itself, and the addition that utilizes the suction force when adding the abrasive to the high pressure jet flow. The addition at the position X ₂ is the easiest and the location where the rust preventive function can be surely exhibited.

In this embodiment, a case where a waste liquid treatment system for environmental protection is incorporated as necessary is shown, but it is not necessary depending on the rust preventive agent.

In another embodiment, the rust preventive agent can be added in a powder state to a predetermined place (for example, an abrasive tank).

Thus, in the processing system incorporating the abrasive recovery and reuse system, the rust prevention of the abrasive extends the reuse life of the abrasive and causes unstable supply due to rusting of the abrasive. Not only can stable operation be performed without a decrease in processing capability, but it also leads to an improvement in the working environment.

[0023]

INDUSTRIAL APPLICABILITY The present invention effectively prevents rust on an abrasive and contributes to reuse of the abrasive and improvement of working environment.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an addition position of an additive when the present invention is applied to an abrasive water jet processing system having an abrasive recovery system.

[Explanation of symbols]

1 Abrasive Water Jet Nozzle 2 Low Pressure Water Pump 3 Pressure Booster 4 Accumulator 5 Abrasive Tank 6 Additive Storage Tank 7 Abrasive Recovery and Reuse System 8 Waste Liquid Treatment System 9 Tap Water X ₁ ~ X ₃ Additive Additive position

(72) Inventor Fujiya Nogami 1-1 No. 1 Tobata-cho, Tobata-ku, Kitakyushu, Fukuoka Prefecture (72) Inside the Yawata Works, Nippon Steel Co., Ltd. No. 1-1 Shin Nippon Steel Co., Ltd., Yawata Works (72) Inventor Hiroyuki Matsumura 3-1-1 Higashikawasakicho, Chuo-ku, Kobe City Kawasaki Saki Heavy Industries, Ltd. Kobe factory (72) Inventor Yoshikazu Ikemoto Kobe 3-1-1 Higashikawasaki-cho, Chuo-ku, Kawasaki Inside the Kawasaki Heavy Industries, Ltd. Kobe factory (72) Inventor Kyoji Tsujita 3-1-1, Higashikawasaki-cho, Chuo-ku, Kobe City Inside the Kawasaki Heavy Industries, Ltd. (72) Inventor Hidehisa Tanaka 3-1-1 Higashikawasaki-cho, Chuo-ku, Kobe City Kawasaki Heavy Industries Ltd. Kobe factory

Claims (1)

[Claims] 1. A high-pressure fluid having a process of pressurizing a carrier fluid, a process of adding an abrasive to a high-pressure fluid jet stream, and a process of recovering and reusing the abrasive contained in the processed fluid as necessary. In a processing method using a high-speed polishing fluid jet in which an abrasive is added to a jet stream, a rust preventive method for an abrasive in a high-speed polishing fluid jet, in which a rust preventive having a corrosion preventing function for the fluid abrasive is added in at least one of the above processes .