JP3377293B2 - Plasma cutting machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma cutting machine provided with a plasma torch for cutting a material to be cut. 2. Description of the Related Art A plasma cutting machine is provided with a smoke exhausting device and a dust collecting device for environmental protection by collecting fumes generated during cutting. In addition, 63-116175
The plasma cutting machine described in Japanese Patent Application Publication No. 60-43231 or Japanese Patent Publication No. Sho 60-43231 is characterized in that air is blown along the back surface of the material to be cut, on the surface opposite to the exhaust air inlet provided on one side surface of the workpiece support platen. The nozzle has an injection nozzle for flowing the air to the exhaust inlet, and the air flow forcibly flushes the fume generated at the cutting section to the smoke exhaust suction port to increase the fume collection efficiency. ing. In the above description, the “back surface” refers to a side opposite to the side where the plasma torch of the workpiece is arranged (the same applies hereinafter). [0003] However, according to the above-mentioned publication technology, since the injection nozzle is provided only on the surface facing the smoke exhaust suction port, fumes generated at the cutting portion cause air from the injection nozzle to flow. It flows along the back of the material to be cut in the flow. For this reason, there is a problem that fumes adhere to the back surface of the material to be cut and the back surface becomes dirty. This is a problem that appears more prominently as the thickness of the material to be cut becomes thicker (that is, when the amount of generated fume is extremely large). [0004] In order to solve the above-mentioned problems, a plasma cutting machine according to the present invention is a cutting machine main body capable of running in a direction along a workpiece supporting platen. In addition, in a plasma cutting machine provided with a shaft on which a plasma torch is mounted so as to be movable in a direction perpendicular to the running direction, the cutting machine body is covered with air at both ends of the shaft. an injection nozzle for spraying a generally opposite direction along the rear surface of the cutting member, and a flow rate adjusting valve for adjusting the exhaust-and pressure of air in the jet nozzle according to the position on the axis of the plasma torch is provided, Opposing sky
Downdraft due to airflow collision and blow-through
It is characterized in that the flow control valve is controlled so that the plasma flow overlaps . According to the plasma cutting machine of the present invention, since the injection nozzle blows air from the substantially opposite direction along the back surface of the material to be cut, the air is opposed at the back surface of the material to be cut. The airflows collide and create a downdraft. As a result, the fumes generated at the cutting portion are forced to flow downward, and the fumes once flowing downward are also pushed down so that they cannot rise again (that is, there is an opportunity for the fumes to come into contact with the back surface of the material to be cut). (Without), and is flushed to the smoke exhaust port. For this reason, according to the above-described invention, the back surface of the workpiece is not stained by fumes. In addition, the on-axis movement of the plasma torch
In conjunction with the movement, the air blowing amount and pressure of the injection nozzle
Providing a flow control valve to adjust the air flow of the injection nozzle
By adjusting the discharge amount and pressure, the descending airflow
And the plasma flow from the cutting section
Downflow, which allows the back of the material to be cut
It is possible to more completely prevent fumes from adhering to the surface. An embodiment of a plasma cutting machine will be described with reference to FIG. The cutting machine body 1 can travel on a rail 4 installed on the floor along a workpiece support platen 3. Further, the cutting machine main body 1 is provided with a shaft 5 disposed above the workpiece support platen 3 in a direction perpendicular to the rail 4. A carriage 6 is mounted on the shaft 5 so as to be movable in the axial direction. A plasma torch 7 is mounted on the carriage 6. At both ends of the shaft 5, there are provided spray nozzles 8 a and 8 b for blowing air from the opposite direction along the back surface of the workpiece 2. The cutting of the material to be cut according to the above embodiment is performed as follows. First, the workpiece 2 is set at a predetermined position on the workpiece support platen 3. When the cutting machine main body 1 runs on the rail 4 and the carriage 6 moves on the shaft 5, the plasma torch 7 obtains a desired position on the workpiece 2 and the plasma torch 7 generates the plasma arc. The cutting material 2 is cut into a desired shape. At the time of cutting, as will be described with reference to FIG. 2, the air jetted substantially opposing from the jet nozzles 8a and 8b flows along the back surface of the workpiece 2 and collides with each other.
The fume 10 is forced to flow downward as the downdraft 9. The fume 10 that has once been swept downwards is
Is pushed downwards and cannot rise again,
It is sent to the dust collector 12 via the smoke exhaust port 11. Another embodiment will be described below. (1) It is preferable that the air from the injection nozzles 8a and 8b collide at the cutting portion. This includes, for example, a plasma torch 7
It is easy to adjust the blowing amount and pressure of the air from the injection nozzles 8a and 8b in conjunction with the movement of the nozzles 5 on the shaft 5. This adjustment is achieved, for example, by providing a flow control valve such as a variable throttle in the air circuit to the injection nozzles 8a and 8b, and controlling the flow control valve in accordance with the position of the plasma torch 7 on the shaft 5. it can. By doing so, the injection nozzle 8
a, the downdraft due to 8b and the blow-by plasma flow from the cutting part overlap, and the best downdraft can be obtained,
This makes it possible to more completely prevent the fume 10 from adhering to the back surface of the workpiece 2. (2) In order to quickly and completely push the fume 10 once lowered down to the smoke exhaust suction port 11, the rail 4 is separated by a partition plate parallel to the axis 5 in the workpiece support platen 3.
It is good to make many small rooms by dividing by direction.
At this time, it is necessary to provide the smoke exhaust port 11 in each room, but only the smoke exhaust port 11 of the room where the plasma torch 7 is located is opened in conjunction with the traveling of the cutting machine body 1 in the direction of the rail 4 so that fumes are opened. 10 should be aspirated. This contributes to the downsizing and energy saving of the smoke exhaust device and the dust collecting device. (3) The installation positions of the injection nozzles 8a and 8b need not be limited to both ends of the shaft 5 as in the above-described embodiment. For example, in FIG. May be worn. Although not shown, the injection nozzles 8a and 8b may be provided on the workpiece support platen 3. When the latter is provided on the workpiece support platen 3, it is preferable that the workpiece support platen 3 be divided into a large number of small rooms as described in (2) above. It is preferable to blow air only from the injection nozzles 8a and 8b of the small room in which the plasma torch 7 is located in conjunction with traveling in four directions. For example, when the material to be cut is long, for example, 2 to 3 m in width × 10 m in length, the amount of air to be blown when the room is not a small room is several hundred liters / min or more, which is large. In the case of a room, a much smaller amount of air is required to obtain a cut product having the same beautiful appearance. (4) The number of injection nozzles 8a and 8b does not need to be limited to one, and the shape and form are tubular (FIG. 3 (a)), elongated (FIG. 3 (b)), and others. What is necessary is just to select suitably. (5) In FIG. 1, the shaft 5 holding the plasma torch 6 is supported on only one side (cantilever structure). However, as shown in FIG. Good. In FIG. 4, the smoke exhaust ports 11 and the like that are actually required are omitted. (6) Further, as shown in FIG. 5, openings 15a and 15b are provided on both sides of the side surface of the workpiece support platen 3 below the back surface of the workpiece 2, respectively. Injection nozzles 8a and 8b may be provided on both sides of the support surface plate 3, respectively, and air may be ejected through the openings 15a and 15b. By doing so, the width of the workpiece support platen 3 can be reduced, and the dust collection efficiency can be improved accordingly. As can be seen from the above embodiment, the present invention is basically a plasma cutting machine provided with an injection nozzle for blowing air from a substantially opposite direction along the back surface of a material to be cut. is there. According to this configuration, as is clear from the above description, it is possible to prevent fumes generated during plasma cutting from adhering to the back surface of the material to be cut. In addition, the following effects also occur. (1) The cleaning of the back surface of the material to be cut, which is a post-process after the completion of cutting required in the prior art, can be omitted. As a result, it is possible to improve the production efficiency and reduce the production cost. (2) Since the appearance of the cut product is improved, the cut product can be used as it is. Further, for example, even when plating or painting is performed as the next step, the plating or painting can be carried out simply by performing simple washing or completely as it is. (3) The prior art reduces the adhesion of the fume to the back surface of the material to be cut by increasing the fume collection efficiency. And the fume collection efficiency depends on the smoke exhaust device and the dust collecting device. Therefore, the specifications of the smoke exhaust device and the dust collecting device are adapted to the maximum material that can be cut by the plasma cutting machine. That is, according to the prior art, the size and complexity of the smoke exhaust device and the dust collecting device cannot be avoided. Further, in the related art in which the injection nozzle is provided on the surface facing the smoke exhaust suction port, if the material to be cut becomes large, fumes cannot be prevented from adhering to the back surface of the material to be cut. On the other hand, the configuration according to the present invention is a configuration in which fumes are not attached to the back surface of the material to be cut in the first place (that is, because it does not depend only on the efficiency of fume collection), the smoke exhaust device and the dust collection device Can be made compact.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a plasma cutting machine according to an embodiment. FIG. 2 is a diagram illustrating the operation of the plasma cutting machine according to the embodiment. FIG. 3 is a view of an exemplary injection nozzle in the plasma cutting machine according to the embodiment, in which (a) is a view of a tubular injection, and (b) is a view of an elongated injection nozzle. FIG. 4 is a schematic view of a plasma cutting machine according to another embodiment. 5A and 5B are schematic views of a plasma cutting machine according to still another embodiment, in which FIG. 5A is a perspective view of a workpiece supporting platen, and FIG.
Is a sectional view thereof. [Description of Signs] 1 Cutting machine body 8a, 8b Injection nozzle 2 Material to be cut 9 Downdraft 3 Material support platen to be cut 10 Fume 4 Rail 11 Smoke exhaust suction port 5 Axis 12 Dust collector 6 Carriage 15a, 15b Cut Opening 7 of material support surface plate Plasma torch

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takao Yamamoto 2-3-6 Akasaka, Minato-ku, Tokyo Komatsu Manufacturing Co., Ltd. (56) References JP-A-2-165868 (JP, A) Japanese Utility Model Application No. 52-140070 (JP, A) Japanese Utility Model Application No. 2-144266 (JP, U) Japanese Utility Model Application No. 49-31932 (JP, U) Japanese Utility Model Utility Model No. 63-1212753 (JP, U) Japanese Utility Model Application No. 6-9768 (Japanese) JP, U) Jikken Sho 53-4190 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 10/00 B23K 7/10

Claims (1)

(1) A cutting machine body capable of traveling in a direction along a workpiece support platen, and capable of moving in a direction perpendicular to the traveling direction. In a plasma cutting machine provided with a shaft equipped with a plasma torch in a cutting machine main body as described above, an injection nozzle for blowing air from both sides of the shaft of the cutting machine main body substantially in the opposite direction along the back surface of the material to be cut.
When descending air by the according to the position on the axis of the plasma torch is provided a flow regulating valve for adjusting the exhaust-and pressure of air in the jet nozzle, the collision of opposing air flow
Flow and the plasma flow from the cutting section
A plasma cutting machine characterized by controlling a flow control valve .