JPH05305437A - Torch for heat cutter - Google Patents

Abstract

PURPOSE:To detect the height at the position faced to a torch regardless of the surface shape of a cutting material and protect the tip part of the torch with a detector by arranging the height detector on the same axis as the torch and slidingly moving the detector on this axis. CONSTITUTION:In the condition of separating the plasma torch 1 from the cutting material at the starting position for cutting, the height detector 8 is slidingly moved over the stroke L. A base plate 2 is shifted to the cutting material side and stopped at the position where the interval between the detector 8 and the cutting material comes to a prescribed size. Successively, the detector 8 is pulled back to make the detector 8 the engaging condition with the tip part of the torch 1. Thereafter, the base plate 2 is shifted to the cutting material side by the stroke L of the detector 8. By this method, the torch 1 is set to the set height position. Even spatter, etc., is scattered at the time of executing the cutting work, this is blocked by the detector 8, and the tip part of the torch 1 is protected. Further, the detector 8 is cooled by the air flowing in the inside thereof and the spatter, etc., hardly sticks.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torch for a thermal cutting machine for cutting a work using a heat source such as plasma, laser or gas.

[0002]

2. Description of the Related Art In a thermal cutting torch using a heat source such as plasma, laser or gas, as shown in FIG. 8, a torch holder b is fixedly attached to a substrate a attached to a main body of a processing machine, and the torch holder b is torch holder b. c is inserted. The height detector e is used to set the torch height during the cutting operation, that is, the distance t1 between the tip of the torch c and the surface of the machine d to be cut to a predetermined dimension (initial height). The height detector e is fixed to the torch holder b so that the lower surface of the detecting portion keeps a distance t2 from the lower end of the torch c.
Further, the detection portion of this is located at a position offset with respect to the central portion of the torch c, and is always moved while keeping a constant distance from the torch c as the torch c moves. Based on the detection data of the height detector e, the height of the torch c is controlled so that the lower end of the torch c is always the optimum height, that is, the distance t1 between the lower end of the torch and the upper surface of the machine d. It has become.

[0003]

Since the detection position of the above-mentioned conventional height detector e is not a position directly under the torch c but a position around the torch c, the machine to be cut warps due to thermal strain or the like. In that case, a difference occurs between the torch height calculated based on the value detected by the height detector e and the actual torch height.
Therefore, there is a problem that even if the torch height is controlled based on the detection result of the height detector e, the torch height is not necessarily set to the optimum. Further, when part of the machine to be cut d is cut off, the height detector e may lose the detection target and may not be detected.

The present invention has been conceived in view of the above, and the height can be detected at the facing position of the torch regardless of the surface shape of the machine to be cut, and the tip of the torch during cutting work can be heightened. An object of the present invention is to provide a torch for a thermal cutting machine, which can be protected by a detector.

[0005]

In order to achieve the above object, a torch for a thermal cutting machine according to the present invention is provided on a tip side of a torch fixed to a substrate 2 at a predetermined distance from a position abutting the tip portion of the torch. A height detector 8 is provided so as to move on the same axis as the torch to a position spaced apart from each other, and the inner shape of the cross section of the height detector 8 is fitted to the tip of the torch 1 with a predetermined gap 9. In addition, the nozzle hole 10 is provided in the axial center portion, the abutment seal member 13 is fitted on the outer peripheral portion of the torch 1 at the edge portion, and the air outlet 1 is formed on the inner surface.
4 is provided. Further, the tip portion of the height detector 8 is constituted by a removable cap 16 which is detachable.

[0006]

[Operation] The height detector 8 is moved from the state where it is fitted to the tip of the torch to the position where it is separated from this torch, and the height between it and the machine to be cut at the position where the torch faces in the separated state is set. After that, the torch is moved to the set position in the fitted state. The thermal cutting operation is performed with the height detector 8 fitted to the tip of the torch. At this time, the tip of the torch is protected by the height detector 8. By making the tip of the height detector 8 a detachable exchange cap 16, this portion can be exchanged at any time.

[0007]

EXAMPLE An example of the present invention will be described with reference to FIGS. In the figure, 1 is a plasma torch which is an example of a torch for a thermal cutting machine, and the plasma torch 1 is detachably attached to a substrate 2 attached to the processing machine body (not shown) side. The substrate 2 is movable with respect to the processing body in the plasma torch 1 in the axial direction over a predetermined stroke. A slide guide 3 and a cylinder device 4 are provided on the substrate 2 in parallel with the plasma torch 1. The guide rod 5 and the cylinder device 4 guided by the slide guide 3 have a bracket 7 at the tip of a piston rod 6. Is fixed, and the height detector 8 of electrostatic capacitance is attached to the bracket 7.

The height detector 8 is the plasma torch 1
It is designed to be positioned on the tip end side and coaxially. The inner shape of the height detector 8 is such that the tip portion of the plasma torch 1 is fitted with a predetermined gap 9, and the tip portion has a nozzle hole 10 facing the tip portion of the plasma torch 1. Is provided. Further, a spacer 1 that contacts the plasma torch 1 on its inner surface and restricts the gap 9 is provided.
1 is fixed, and the spacer 11 has an air passage 12
Are provided in the axial direction. The spacer 11 is made of an insulating material.

The seal member 1 is provided inside the opening of the spacer 11.
3 is fitted, the air outlet 14 is opened from the fitting position of the seal member 13 to the tip side, and the air pipe 15 is connected to the air passage 14a communicating with the air outlet 14. .. The outer shape of the height detector 8 is a mountain shape with the tip as the top. The tip of the height detector 8 may be integrally formed with other parts as shown in FIG. 1, but as shown in FIG. Good.

The height detector 8 is of the electrostatic capacitance type as described above, and is as shown in FIG. 3, and the height detector 8 to which a constant electric charge is applied is a covered object which is a conductor. The sensor 18 detects a change in electrostatic capacitance when the cutting machine 17 is approached, and the sensor amplifier 19 amplifies the change to the height adjuster 20.
The height adjuster 20 calculates a predetermined height dimension, and the output signal is input to the controller 21. The controller 21 performs various calculations, and based on the results, drives the torch lifting motor 22 to lift the plasma torch 1.

In the above structure, the height detector 8 is moved with respect to the plasma torch 1 over a predetermined stroke L, and is fitted to the tip end portion of the plasma torch 1 while being moved to the plasma torch 1 side. The operation will be described below with reference to FIGS. 4 to 7. (1) The height detector 8 is moved over the stroke L while the plasma torch 1 is separated from the machine to be cut 17 at the cutting start position (FIG. 4). (2) In this state, the substrate 2 is moved to the machine to be cut 17 side and stopped when the distance between the height detector 8 and the machine to be cut 17 reaches a predetermined dimension (FIG. 5). At this time, the movement amount is controlled by the height detector 8 according to the detected value. (3) Then, the height detector 8 is pulled back. As a result, the height detector 8 is fitted to the tip of the plasma torch 1 (FIG. 6). (4) After that, the substrate 2 is moved to the machine 17 side by the stroke L of the height detector 8. As a result, the plasma torch 1 is set at the height position set in (3) above (FIG. 7). In this state, at the cutting start position, the height position of the facing portion of the plasma torch 1 is directly detected and set.

The plasma torch 1 starts the thermal cutting work with the height set as described above. At this time, the plasma arc from the plasma torch 1 is detected by the height detector 8
It is ejected through the nozzle hole 10 of. And at this time,
Air is supplied from the air pipe 15 and passes through the inside of the height detector 8 to be jetted from the nozzle hole 10, and the height detector 8 is cooled during this period.

Spatters and the like are scattered from the cutting portion by the above cutting work, but these are shielded by the height detector 8 and the tip portion of the plasma torch 1 is protected from the above spatters and the like. At this time, since the height detector 8 is cooled by the air flowing inside the height detector 8, the spatter and the like are less likely to adhere to it. Even so, the tip portion of the height detector 8 may be damaged by cutting work for a long time, but in this case, this portion is used as the replacement cap 16 as in the embodiment shown in the drawing, and this is replaced with the replacement cap 16. Replace as needed.

[0014]

According to the present invention, since the height detector 8 is arranged coaxially with the torch and the stroke is made coaxially, the torch is opposed regardless of the surface shape of the machine to be cut 17. The height can be detected at the position, and the tip of the torch during the cutting operation can be protected by the height detector 8. Further, by using the replacement cap 16 in which the tip of the detector 8 is detachable, the service life of the height detector 8 can be extended.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing another example of the height detector.

FIG. 3 is a circuit configuration diagram of a height detector.

FIG. 4 is a first operation explanatory view of the present invention.

FIG. 5 is a second operation explanatory view of the present invention.

FIG. 6 is a third operation explanatory view of the present invention.

FIG. 7 is a diagram for explaining the fourth operation of the present invention.

FIG. 8 is a front view showing a conventional example.

[Explanation of symbols]

1 ... Plasma torch, 2 ... Substrate, 3 ... Slide guide,
4 ... Cylinder device, 5 ... Guide rod, 6 ... Piston rod, 7 ... Bracket, 8 ... Height detector, 9 ... Gap, 1
0 ... Nozzle hole, 11 ... Spacer, 12 ... Air passage, 13
... Seal member, 14 ... Air outlet, 14a ... Air passage,
15 ... Air piping, 16 ... Replacement cap, 17 ... Machine to be cut.

Claims (2)

[Claims] 1. A height detector 8 is provided on the tip side of a torch fixed to a substrate 2 so as to move coaxially with the torch from a position abutting the tip of the torch to a position spaced apart by a predetermined distance. The height detector 8 has a cross-section inside shape which is fitted to the tip of the torch 1 with a predetermined gap 9, a nozzle hole 10 is provided at the axial center portion, and the torch is provided at the edge portion. 1. A torch for a thermal cutting machine, characterized in that an abutment seal member 13 is fitted to the outer peripheral portion of 1 and an air outlet 14 is provided on the inner surface. 2. The torch for thermal cutting according to claim 1, wherein the tip of the height detector 8 is constituted by a detachable replacement cap 16.