JPH044922B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a cutting method for easily producing plates of various sizes and shapes, and plates having openings of various shapes, in large lightweight foam concrete plates and ordinary pre-cast plates. It's a method. In general, large plates with a width of 600 m/m or more for lightweight foam concrete and ordinary pre-cast plates are flat cast, in which reinforcing bars are placed horizontally to the bottom plate of the form, and mortar slurry is injected into the form. This method is manufactured by curing after reaching a semi-hardened state.

Conventionally, when manufacturing plates whose length and width are smaller than the bottom plate, when manufacturing two or more plates with one formwork, when manufacturing plates with a planar shape other than rectangular, a partition plate was installed inside the formwork. It is molded by placing it in the width direction, length direction, etc. and between the plates. In addition, when manufacturing plates with rectangular or other shaped openings, injection is performed after placing a partition in the shape of the opening (usually called an opening jig) in the formwork to block the mortar slurry. It is manufactured by doing. However, both cases had the following drawbacks.

1. Setting and fixing the partition plates is extremely time consuming.

2. Various partition plates and opening jigs must be provided for each formwork.

Therefore, the present invention seeks to solve the above-mentioned problems, and although it is commonly put into practical use in the ceramics industry and many other plastic processing industries, the brittle and non-adhesive nature of semi-hardened mortar has not been found in the field of concrete panel manufacturing. (1)
Incorporating this into the development of a cutting method using a flat-blade knife, which has not been put to practical use due to problems such as easy chipping and (2) non-smooth cutting surfaces, the cutting hardness, direction of blade movement, blade thickness, blade We conducted experiments by changing the moving speed of the robot. As a result of intensive research, it was discovered that under certain specific conditions, the method can be put to practical use without causing the above-mentioned problems.

The specific conditions are a hardness of 5 to 30 [lb/in ² ].
In the semi-hardened state, cut the semi-hardened mortar on the bottom plate using a flat-blade knife with a blade thickness of 1 to 3 mm, tilting it in the cutting direction so that the angle between the bottom plate and the blade is 30 to 60°, and place it against anything. The purpose is to move the tip of the blade in contact with the bottom plate at a speed of 100 mm/sec or less without backing up. Figure 1 shows the case of cutting, and Figure 2 shows the case of cutting out the opening.

Next, cutting conditions such as cutting hardness, blade movement direction, blade thickness, and blade movement speed will be explained in detail.

1 Semi-hardened mortar hardness Hardness is measured by the resistance when a cylinder with a diameter ^of 20 m/m is pressed against the object to be cut and buried to a depth of 35 m/m. It is essential to perform the cutting within the range.

If it is less than 5 [lb/in ² ], the adhesion of the mortar is high, and the cut surface will be damaged regardless of other conditions. If it is more than 30 [lb/in ² ], the strength will be too high.
Furthermore, brittleness increases, resulting in damage to the upper part of the cut surface.

2. Method for moving the blade The present invention, as shown in FIG. 3, moves the tip of the blade 3 in the cutting direction while keeping it in contact with the bottom plate 2. A method of moving the cutter while reciprocating up and down is also considered, but this has the advantage of lower cutting resistance and less occurrence of defects, but the cut surface will be uneven. This is undesirable because an uncut portion occurs at the bottom of the cut surface. In addition, the inclination angle with respect to the cutting direction is
If it is less than 30°, a break will occur at the top of the cut surface, and if it is more than 60°, the accuracy and flatness of the cut surface will decrease.
Cuts should be made at a bevel angle of 60°.

3. Blade thickness Blade thickness has a close relationship with cutting hardness; the upper limit of blade thickness is controlled by the plasticity of the mortar, and the lower limit is controlled by the bending strength of the blade. Therefore, the relationship between the lower limit and the case where a steel cutter is used is shown in FIG. In the figure, the shaded area is valid, the upper limit is represented by a solid line, and the lower limit is represented by a broken line. Therefore, cutting should be performed using a blade with an effective blade thickness of 5 m/m or less within a predetermined cutting hardness range.
Note that within this range, it is preferable to cut with a blade as thin as possible for smoothness of the cut surface.

4. Shape of the blade When the cross-sectional shape of the blade is important, when the smoothness of the cutting surface is important, it is better to have a shape where the parts other than the cutting edge are parallel, as shown in Figure 5. If cutting accuracy is important, a blade 3 having a tapered shape in areas other than the cutting edge, as shown in FIG. 5, is excellent. Therefore, it is preferable to use them properly as necessary.

Further, as for the shape of the cutting edge, a straight one is preferable to a curved one in terms of the smoothness of the cutting surface. Regarding the blade width, the narrower the blade, the lower the resistance of the mortar and less likely to cause chipping, but the smoothness of the cut surface is not good. Moreover, if it is too wide, mortar will easily adhere to the blade, resulting in chipping. Therefore, in the case of a steel blade, it is preferable to set it to 30 to 100 mm.

5 Cutting speed Within the above conditions, the cutting speed is 100mm/sec
It should be: If the speed is higher than this, the cutting resistance increases, the precision of the cut surface decreases, and defects occur in the upper part of the cut surface.

As an example, cutting hardness is 20 [lb/in ² ], blade thickness is 4 mm,
When cutting was performed using a flat blade with a blade width of 40 mm at a cutting speed of 110 mm/sec, peeling occurred at the top of the cut surface.

The present invention has discovered that if semi-hardened mortar is cut with a flat knife under the conditions described above, a smooth cut surface can be obtained without causing any defects.

In addition, when carrying out the cutting method of the present invention, a box-shaped frame is assembled on the formwork for the experiment of the present invention.
We used a device that manually moves the flat-blade knife using a mechanism that slides the frame based on a reference, but for practical use, we need a device that automates the raising and lowering of the experimental knife and the cutting movement, and a device that moves the flat-blade knife manually. It is conceivable that the knife could be operated by a robot.

〔Example〕

As an example of cutting in the length direction, the grain size is 300μ.
A mortar slurry was prepared by adding 70% water to solid ingredients such as crushed silica stone of less than 200 m in size and quicklime cement, and adding a small amount of a foaming agent. The raw material slurry was placed horizontally with reinforcing bars for the width 1500mm x length x 4200mm x thickness 200mm.
It was poured into a mm mold. When the mortar slurry foamed and the hardness reached 20 [lb/in ² ], the formwork on the rail was moved under the box-shaped frame cutting test device, and the blade thickness was 3 mm, the blade width was 30 mm, and the cutting edge was A straight, flat-blade knife was set at a position with a width of 1500 mm, and the knife was tilted at an angle of 30° in the cutting direction while the tip of the blade was in contact with the bottom plate. Then, longitudinal cutting was performed at a cutting speed of 80 mm/s. After curing this product, we measured the condition of the cut surface of the plate and found that there were no defects at all, and the flatness was 2 mm.
Good results were obtained, with no cutting marks at all in terms of smoothness.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of knife cutting in the width and length directions, Fig. 2 is an explanatory diagram of opening knife cutting, and Fig. 3 is an explanatory diagram of knife cutting in the width and length directions.
The figure is a sectional view of knife cutting, FIG. 4 is a diagram showing the applicable range of cutting hardness and blade thickness, and FIG. 5 is a sectional view of the knife shape. 1: semi-hardened mortar; 2: formwork bottom plate; 3:
Has a mortar cutting knife.

Claims (1)

[Claims] 1. Place a semi-hardened mortar panel with a hardness of 5 to 30 [lb/in ² ] on the bottom plate, and use a flat blade knife with a blade thickness of 1 to 3 mm to make the angle between the bottom plate and the blade 30 to 60. Cut the panel and cut out the opening in the panel by tilting the blade in the cutting direction so that it is at an angle of 100° and moving the tip of the blade in contact with the bottom plate at a speed of 100 mm/sec or less without applying anything. A method for cutting semi-hardened mortar panels, which is characterized by: