JPH0639060B2 - How to cut a wall with an abrasive jet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for cutting a wall by an abrasive jet, and particularly, a wall cutting by an abrasive jet in which the moving speed of a jet nozzle is preferably controlled. Regarding the method.

[Prior Art] A cutting method using an abrasive jet in which a granular material such as sand is sprayed together with a high-pressure water jet onto an object to be cut, such as a concrete structure or rock, to cut the object is known, and various objects to be cut are known. It is used when cutting.
In particular, the cut surface is clean, and an arbitrary cut surface can be formed by moving the jet nozzle, which is preferable. For example, it is suitable for construction for cutting a wall of a concrete building to remodel the building. However, since the concrete wall has reinforcing bars inside it, if the jet nozzle moving speed is determined according to the location of the reinforcing bars, the energy of the jet will be wasted in the areas without the reinforcing bars and the durability of the jet reflector will decrease. Then
The cutting time becomes longer. On the contrary, if the moving speed of the jet nozzle is determined in accordance with the place where there is no reinforcing bar, there is a problem that the cutting of the reinforcing bar becomes insufficient.

[Object of the Invention] Accordingly, an object of the present invention is to provide a method of cutting a wall by an abrasive jet for cutting a wall including a member different from the main material inside a reinforced concrete wall or the like at an optimum cutting speed.

According to the present invention, according to the present invention, one of the wall surfaces is movably provided with a jet nozzle for ejecting the granular material together with the high-pressure water jet, and the other is provided with a jet reflector, and the jet nozzle and the jet reflector are provided on both sides of the wall. In a method of cutting a wall by an abrasive jet, a vacuum chamber is provided to store, both vacuum chambers are connected to a vacuum pump, and a slurry generated at the time of cutting is sucked and collected by the vacuum pump through the vacuum chamber. Vibration detection means is provided on the back surface of the jet reflector side vacuum chamber, the vibration is detected and converted into an electric signal, the electric signal is amplified, and the penetration degree of the wall is judged by the magnitude of the amplified electric signal. When it is smaller than the reference value, the moving speed of the jet nozzle is decelerated from the reference speed.

[Advantageous Effects of the Invention] Therefore, when the penetration is smaller than the reference value, that is, at the portion where the reinforcing bar is difficult to penetrate, the moving speed of the jet nozzle is set lower than the reference speed to increase the energy applied to the portion to ensure the operation. When cut into, and the penetration is the standard value,
That is, in the place of only concrete, the wall is cut with the moving speed of the jet nozzle as the reference speed. As a result, the concrete wall can be reliably and quickly cut by effectively using the energy of the jet, and the durability of the jet reflector can be improved.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an outline of a cutting device for carrying out the present invention, in which a concrete wall W in a room is cut by an abrasive jet (hereinafter referred to as jet) J using a jet nozzle (hereinafter referred to as nozzle) N. However, it is shown. High-pressure water is supplied to the nozzle N from a high-pressure pump (not shown), and granules are sent from an abrasive line (not shown). The nozzle N is attached to the nozzle traveling device D driven by the nozzle moving motor M and is movable along the wall surface Wa.
The jet reflector A is provided on the b side. The end of the nozzle N is housed in a nozzle cover Ca, which is a vacuum chamber supported by one wall surface Wa, and the jet reflector A is a back surface protective cover C, which is a vacuum chamber supported by the other wall surface Wb.
A vibration sensor S, which is a vibration detecting means, is provided on the back surface of the back protective cover Cb. The vibration sensor S is connected to a nozzle speed controller NC via a vibration amplifier SA, and the nozzle speed controller NC is connected to a nozzle traveling motor M.

At the time of cutting, the moving speed of the nozzle N is set to an appropriate value for the concrete mechanical strength and thickness of the wall W and the required jet injection pressure, and is set as the reference speed.

When cutting the wall W, which is a concrete structure, as shown in FIG. 2 (a), FIG.
As shown in, the vibration level is relatively large, and this value is used as a reference value. That is, in the case of concrete, after the jet J cuts the wall W, the jet J directly collides with the jet reflector A along with the slurry by the residual force.
Input is large.

On the other hand, as shown in FIG. 3A, when the jet J from the nozzle N collides with the reinforcing bar I in the wall W, when the nozzle N is moved at the reference speed, the jet J is scattered without penetrating. Therefore, the jet reflector A hardly vibrates. Therefore, as shown in FIG. 3 (b), vibration with a small vibration level is detected.

Next, one aspect of the method of the present invention will be described.

In FIG. 4, the vibration sensor S detects the vibration of the rear protective cover Cb and converts it into an electric signal (procedure 1). The vibration amplifier SA amplifies the electric signal from the vibration sensor S (procedure 2), determines the penetration of the wall W based on the magnitude of the electric signal (procedure 3), and outputs a speed control signal to the nozzle speed controller NC. That is, the magnitude of the electric signal is
When it is less than the reference value, it is determined that the penetration is low (not penetrated), a deceleration signal is output, and when it is at the reference value or greater than the reference value, it is determined that it is penetration, and when it is moving at the reference speed, it is controlled. If no signal is output and the vehicle is moving in deceleration, an acceleration signal to the reference speed is output. The nozzle moving motor M drives the nozzle moving device D based on the control signal from the nozzle speed controller NC to move the nozzle N (procedure 4).

The above control mode is not limited to this, but the movement of the nozzle N is performed intermittently, the moving speed is set to a small interval interval, and when the nozzle N is stopped at a certain position and the penetration of the jet N is detected, The nozzle N may be moved to the next location.

FIG. 5 is a diagram showing the vibration level on the vertical axis and the time on the horizontal axis in order to show a specific vibration level when the present invention is implemented.

In the figure, since the vacuum pump is operated at the point a, the vibration sensor S detects minute vibration due to suction. Then, the cutting operation was started at the point b.
Since the rebar was detected at point c, the vibration level decreased,
In that case, the motor is decelerated. Since the reinforcing bar was cut at the point d, the vibration level immediately after cutting was relatively large as indicated by the symbol e. Therefore, the cutting work is accelerated.
Between the points f and g and between the points h and i, the reinforcing bars are being cut in the same manner as described above. That is, in the illustrated example, three reinforcing bars are provided. The cutting work was performed in this way, and the cutting work was completed at the point j. Subsequent vibration was due to vacuuming, and at point k the vacuum pump was stopped.

Thus, according to the present invention, the state of cutting can be known by the vibration level.

[Summary] As described above, according to the present invention, the penetration is determined based on the magnitude of vibration, and when the penetration is small, the moving speed of the nozzle is reduced, and as a result, the energy of the jet is effectively used. To cut the wall surely and quickly,
The durability of the jet reflector can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic explanatory view showing an example of a cutting device for carrying out the present invention, and FIG. 2 (a) is an explanatory view showing a place where a jet penetrates a concrete structure. Fig. 2 (B) shows the vibration level at that time, Fig. 3 (A) is an explanatory view showing the place where the jet collides with the reinforcing bar, and Fig. 3 (B) shows the vibration level at that time. 4 and 5 are control procedure diagrams, and FIG. 5 is a diagram showing vibration levels when the wall surface is actually cut. A ... Jet reflector, Ca ... Nozzle cover, Cb ...
… Rear protective cover, D… Nozzle moving device, J… Abrasive jet, M… Nozzle moving motor, N… Jet nozzle, NC… Nozzle speed controller,
S ... Vibration sensor, SA ... Vibration amplifier, W ... Wall

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Yoshida 2-1-11-1 Tobita-cho, Chofu-shi, Tokyo Inside Kashima Construction Co., Ltd. Technical Research Institute (72) Kenji Nishi Nishi 2-1-11-1 Tobita-cho, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Institute (72) Inventor Takatoshi Isobe 2-191-1 Tobita-cho, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Laboratory (72) Inventor Ishibashi ▲ Jo ▼ Osamu Tobita, Chofu-shi Tokyo 19 No. 1 within Kashima Construction Co., Ltd. Technical Research Institute (56) Reference JP-A-62-199400 (JP, A) JP-A-53-34491 (JP, A)

Claims (1)

[Claims] 1. A vacuum chamber for movably providing a jet nozzle for jetting particulate matter together with a high-pressure water jet on one of the wall surfaces, a jet reflector for the other, and a vacuum chamber for housing the jet nozzle and the jet reflector on both sides of the wall. In the method of cutting a wall by an abrasive jet, in which both vacuum chambers are connected to a vacuum pump and the slurry generated at the time of cutting is sucked and collected by the vacuum pump through the vacuum chamber, Vibration detection means is provided on the back side, vibration is detected and converted into an electrical signal, the electrical signal is amplified, and the penetration level of the wall is judged by the magnitude of the amplified electrical signal, and when the penetration level is smaller than the reference value. A method of cutting a wall by an abrasive jet, characterized in that the moving speed of a jet nozzle is reduced from a reference speed.