JPH0569677B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a waterjet cutting method in which cutting is performed using ultra-high pressure water and high-speed jetting of abrasive material.

<Conventional Technology> Currently, there is a cutting technology that cuts concrete, steel, etc. by jetting ultra-high-pressure water together with an abrasive material from tiny jet holes.

<Problems to be Solved by the Present Invention> The above cutting technology has the following improvements.

(b) For example, when it is desired to cut a concrete column with a wall thickness of several meters, cutting with a water jet is extremely difficult, and there is a limit to the wall thickness of the object to be cut.

(b) The jet speed of the water jet decreases as it goes deeper from the surface of the object to be cut.

As the jet speed decreases, the cutting ability also decreases.

Therefore, the same point must be cut back and forth many times, resulting in poor cutting efficiency.

(c) When cutting a thick object, the jet stream from the water jet is initially concentrated in one direction, but when it reaches a certain depth, the jet stream becomes turbulent.

Therefore, there are problems such as cutting off the planned cutting line or resulting in a cut surface with many unevenness.

<Object of the present invention> An object of the present invention is to provide a waterjet cutting method that can cut an object with high efficiency without being limited by the wall thickness of the object to be cut.

<Means for Solving the Problems> In the present invention, first, a boring hole is opened in the object to be cut.

Next, cutting is performed by spraying a water jet from the outer surface of the object toward the borehole.

Then, the cutting debris collected in the borehole is
This relates to a cutting technique that uses suction and collection.

<Example> Next, although it is possible to adopt the object to be cut in the form of a cylinder or a polygonal column, the present invention will be described with reference to the drawings, using a prismatic column made of reinforced concrete with a square cross section as an example of the object to be cut. The cutting technique will be explained.

(1) Opening a borehole A borehole 2 is opened near the center of the object 1 to be cut along the planned cutting line.

The borehole 2 can be easily opened by known core boring or the like.

In addition, when the object 1 to be cut is a cylinder, the boreholes 2 may be opened in a criss-cross shape.

(2) Preparation for water jet cutting [Installation of closing plates] Closing plates 3 such as steel plates are placed at both ends of the borehole 2 made in the object 1 to be cut.

This closing plate 3 is arranged for the purpose of preventing the scattering of cutting chips blown into the borehole 2 by the jet of waterjet, and also to prevent noise during cutting.

One end of a suction hose 6 is connected to the plate surface of the closing plate 3.

The other end of the suction hose 6 is a vacuum pump 61
It is configured so that cutting waste generated in the borehole 2 can be collected by connecting to the borehole 2.

[Setup of spray nozzles] On one or both sides of the object to be cut 1, there is arranged a spray nozzle 4 that sprays particles made of a mixture of ultra-high pressure water and abrasive material at an ultra-high speed.

A supply hose extending from a water tank 8 and an abrasive tank 9 is connected to the base end side of the injection nozzle 4 .

The injection nozzle 4 is configured to be supported so as to be movable along the axis of the borehole 2.

Note that the method of supporting and operating means for the injection nozzle 4 are based on known methods.

(3) Start of cutting Ultra-high pressure water is injected from the injection nozzle 4 together with the abrasive material at high pressure.

The injected ultra-high pressure water containing abrasive material cuts the workpiece 1 from the outer surface side to the borehole 2.
reach.

The cutting operation is carried out while moving the injection nozzle 4 along the planned cutting line.

Cutting debris generated by cutting is ejected into the borehole 2 together with ultra-high pressure water containing an abrasive.

(4) Collection of cutting waste, etc. Ultra-high pressure water containing abrasive material and cutting waste ejected into the borehole 2 are collected by suction with the suction hose 6.

Other Examples 1 (Figures 2 and 3) When the object 1 to be cut is a cylinder and the cylinder is to be cut in the circumferential direction, the following cutting device may be used for cutting. is also possible.

<A> Cutting device The cutting device is composed of two sets of injection nozzles 4 and an exterior ring 5 to which these injection nozzles 4 are swingably attached.

<B> Exterior ring The exterior ring 5 is a member whose purpose is to surround and fix the outer periphery of the object 1 to be cut, which is a cylindrical body.

The exterior ring 5 is made up of two curved plates 51, for example, by dividing a ring-shaped band plate into two.

Both ends of each curved plate 51 are bent outward to form a flange 52.

The exterior ring 5 is formed not to have a length that allows the opposing flanges 52 to come into close contact with each other when surrounding the circumferential surface of the object 1 to be cut, but to have a length that can maintain a constant facing distance between the flanges 52.

One end of a suction hose 6 is connected to the surface of the curved plate 51 so as to be able to suction and collect cutting waste ejected into the borehole 2 as described later.

<B> Method of installing the injection nozzle Between the opposing flanges 52 of each curved plate 51,
An injection nozzle 4 is attached to an exterior ring 5 so as to be swingable in the circumferential direction.

In order to attach the injection nozzle 4 so that it can swing freely, for example, as shown in FIG. 3, two sets of upper and lower fastening bolts 53 are inserted between the opposing surfaces of the flange 52 and arranged.

A communication member 54 is arranged between the midpoints of the two sets of upper and lower fastening bolts 53 in a direction perpendicular to the fastening bolts 53.

The intersection between the communication member 54 and the fastening bolt 53 has a structure that allows the communication member 54 to rotate.

Therefore, by attaching the injection nozzle 4 across the communication member 54, the injection nozzle 4 can freely move in the injection direction on the outer ring 5.

<C> Cutting method (FIG. 2) [Opening a borehole] A borehole 2 is opened in a cylindrical object 1 to be cut in a direction perpendicular to the axis of the object 1 to be cut.

[Setting the cutting device] The cutting device having the above structure is attached to the outer periphery of the object 1 to be cut so as to prevent it from falling off.

In addition, a soft material 7 is provided between the object to be cut 1 and the outer ring 5.
In some cases, there may be an intervention.

[Start of Cutting] Cutting is started by spraying ultra-high pressure water containing an abrasive toward the borehole 2 from two sets of injection nozzles 4 that are swingably attached to the exterior ring 5.

The injection nozzle 4 moves in the injection direction while swinging its head in the direction of the circumferential surface of the object 1 to be cut.

[Suction recovery of cutting waste, etc.] Ultra-high pressure water containing abrasive and cutting waste injected from each injection nozzle 4 are ejected into the borehole 2 in the same manner as in the embodiment described above, and then are collected using the suction hose 6. Collect by suction.

[Processing of uncut portions] There is a limit to the swing range of each injection nozzle 4.

Therefore, as shown in FIG. 2, an uncut portion 12 occurs on a part of the outer surface side of the object 1 to be cut.

The following two methods can be considered for processing the uncut portion 12.

(A) Manual processing method The cutting device is removed and the uncut portions 12 are removed, or if reinforcing bars remain, they are processed by gas cutting.

(B) Processing method using a cutting device Without removing the cutting device attached to the object 1, the cutting device is rotated in the circumferential direction, and the uncut portion is removed by the jet stream from the injection nozzle 4. Process the cutting.

<D> Effects of this embodiment According to this embodiment, although it is difficult to arrange the injection nozzle 4 in a direction perpendicular to the axis of the cylindrical body and move the injection nozzle 4 around the circumference, it is possible to oscillate the injection nozzle 4. By freely attaching it, there is 1 uncut area.
Most parts can be easily cut by leaving only a small amount of 2.

Moreover, by arranging the outer ring 5 around the outer periphery of the object to be cut 1, not only can cutting debris and the like be prevented from scattering, but also a high soundproofing effect can be obtained.

Note that if three or more sets of injection nozzles 4 are provided on the exterior ring 5, the above-mentioned untreated area 1
Can be cut without generating 2.

<Effects> As described above, according to the present invention, the following effects can be expected by opening a boring hole in the object to be cut and performing the cutting operation.

(a) Even if the object to be cut is thick, the distance cut by the water jet is essentially only the distance from the outer surface to the borehole.

Therefore, no matter how thick the wall is, it can be cut.
There is no restriction on the meat pressure of the object to be cut.

(b) The present invention is a cutting technique in which waterjet is injected onto the object to be cut, and the object is not cut all at once, but cut deeper in stages in several steps.

Therefore, the waterjet jetting speed does not suddenly decrease in the deep part of the object to be cut, and the cutting ability can be increased.

Therefore, it is possible to accurately cut along the planned cutting line.

Furthermore, the cut surface can be cut cleanly without any unevenness.

(c) Conventional technology includes a method of cutting a concrete body by injecting jet from a plurality of boreholes formed in the object to be cut.

However, with this method, if the inside of the concrete structure is cut to hollow out, the cutting waste will not scatter, but if the material is cut to the surface of the structure, the jet will be injected from within the borehole, so the cutting waste will cover the surface of the structure. It breaks through and scatters outside.

Therefore, there is a major drawback in that the work must be carried out under unsanitary working conditions.

In contrast, in the present invention, a blocking plate is attached to the outer surface of the object to be cut, other than the part to which ultra-high pressure water is sprayed, to prevent cutting debris from scattering.

Therefore, this blocking plate can effectively prevent cutting debris from scattering and create a clean working environment.

[Brief explanation of drawings]

Figure 1: A perspective view of cutting work using a water jet, Figure 2: An explanatory diagram of the cutting technique when cutting a cylindrical body, Figure 3: An explanation of the oscillating structure of the injection nozzle. figure.

Claims (1)

[Scope of Claims] 1. A boring hole is opened in the direction in which the object to be cut is planned to be cut, and one end of a suction hose for cutting waste is located in the bore hole, and ultra-high pressure water is applied to the outer surface of the object to be cut. In addition to the part where the water is sprayed, a blocking plate is installed to prevent cutting debris from scattering, and ultra-high pressure water is sprayed from the outside of the workpiece towards the outer surface of the workpiece, and the A waterjet cutting method characterized by cutting the frame between the borehole and the borehole.