JPH0622549Y2 - Plasma cutting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a plasma cutting device for automatically cutting the feeder and runner of a cast product by a plasma arc.

[Conventional technology]

As is well known, the feeder and the runner portion of the cast product taken out of the mold are cut, but such cutting work is generally performed manually using a gas torch. However, in recent years, it has been attempted to utilize industrial robots in order to save the labor for cutting the feeder and runner.

However, in addition to the dimensional accuracy of the cast product being worse than that of the machined product, it is difficult to automate the cutting work due to the difficulty of positioning the torch with respect to the cast product, especially in the case of a product with a complicated shape. It has to be economically disadvantageous, and cutting of the riser section and runner section of a cast product with a complicated shape is done manually, and only the cast product with a simple shape can be cut by the automatic cutting device. This is the current situation.

Among the above-mentioned automatic cutting devices, there is a plasma cutting device which utilizes a plasma arc. Therefore, the plasma cutting device will be described with reference to FIG. 3 which is a perspective view thereof.
(1) is a plasma torch (hereinafter referred to as a torch),
This torch (1) is a stand bar standing on the carriage (d).
It is held by the tip of a torch holder (b) which is supported by (c) so as to be vertically adjustable. The traveling platform (d) is movably supported by a pair of tracks (f) laid in parallel on the upper surface of the supporting platform (e), and a pinion (not shown) provided at the bottom of the traveling platform (d). ) Is this pair of orbits (f)
It is designed to mesh with the rack (g) provided between the two. Further, a traveling operation panel (h) is connected to the traveling platform (d) to control the rotation of the pinion so that the traveling platform (d) can be reciprocally moved on the pair of tracks (f). It is configured as follows.

It should be noted that what is placed below the tip of the torch (1) is the cast product (w) before cutting the feeder (W ₁ ).

Hereinafter, the usage mode of the plasma cutting device having the above-mentioned configuration will be described. A feeder (W ₁ ) of a cast product (w) is shown by a broken line (1) in the figure.
When cutting along the line, first move this casting (w) so that the longitudinal direction of the broken line (1) and the track (f) are parallel, and one end is supported by the stand bar (c). Loosen the grip on the tip of the torch holder (b), and manually adjust the vertical position so that the distance between the casting (w) and the torch (1) is the specified cutting distance. To fix. Then
Align the tip of this torch (1) with one end of the broken line (1) and
A plasma arc is jetted from (1) and a traveling operation panel
By operating the operation button of (h), the traveling platform (d) is moved along the track (f) to the other end side of the broken line (1).

[Problems to be solved by the device]

The plasma cutting device described above is useful as such,
From the viewpoint of cutting work versatility, etc., there are still problems as described below.

That is, if there is unevenness or height difference in the feeder due to the shape of the cast product and the distance between the cutting part and the torch changes as the cutting progresses, the distance between the cutting part and the torch may change. Since the distance can not be automatically adjusted, there is a problem in versatility that the shape of the cast product that can be cut is limited.

In addition, the cutting material of the feeder of the cast product must be adjusted to the traveling direction of the traveling table, and the position of the cast product must be adjusted by moving the cast product so that the trajectory of the torch holder matches.
Further, in the case where the shape of the cast product is complicated or the shape is poor in stability, the cutting work efficiency is remarkably reduced because a long adjustment work is required for positioning the cast product. There will be points.

Therefore, an object of the present invention is to provide a highly versatile plasma cutting device that can be used for cutting the feeder and runner even if the casting has a complicated shape.

[Means for Solving the Problems]

The present invention has been made to solve the above problems. Therefore, the structure of the plasma cutting apparatus according to the present invention is rotatably supported around a vertical axis and has a plurality of joints and the rotation. An arm provided with a braking device at the support portion and the joint portion, a frame body that is rotatably supported around the axis at the tip of the arm and that supports a support body that supports the torch in a vertically movable manner, An operating device for operating the support body and an operation signal from a memory reproducing device for storing a position teaching operation for starting and ending cutting of a material to be cut by a torch of the operating device, the operation signal from the pilot arc to the main arc, and then the supporting In addition to controlling the movement of the body based on a stop signal from a timer that stops the movement for a predetermined period, the distance between the tip of the torch and the material to be cut is determined based on the arm length signal from the detection unit that detects the arm length. Characterized by comprising a control unit for controlling such that a constant spacing.

[Action]

According to the plasma cutting device of the present invention, the torch can be freely moved along the cutting line of the material to be cut by releasing the braking force of the braking device provided on the rotation support portion of the arm and the plurality of joints. Further, when the brake is applied, the arm is fixed, and the movement range of the torch previously taught by using this movement is stored by the storage / reproduction device. Then, in this state, when the support is moved through the controller based on the memory of the memory reproducing device, the pilot arc of the plasma is ignited, and the arc voltage detects that the torch has reached the cutting position of the material to be cut. Then, simultaneously with the transition from the pilot arc to the main arc, the movement of the torch is stopped for a so-called piercing time until the plasma completely cuts the cut portion of the material to be cut. After that, the movement of the support is continued until the cutting is completed, but since the arc voltage changes when the distance between the cutting part and the torch tip changes due to the change in the height of the cutting part during cutting, This change is detected by the detection unit that detects the arc length, and the operation of the support body is continuously controlled by the control device based on the detection signal from the detection unit.

〔Example〕

An embodiment of the present invention will be described with reference to FIG. 1 which is a schematic configuration explanatory view of a plasma cutting apparatus and FIG. 2 which is a front view of the configuration of a torch moving portion in FIG.

That is, reference numeral (1) is a torch, and the torch (1) was gripped by a holder (2) provided on an actuating device (3) as a support. Then, the actuator (3) is rotatably supported around the shaft center through a brake (b ₅ ) on a vertical shaft rotatably provided on the U-shaped frame (4), and further the actuator (5) is supported by the actuator (5). And reciprocally move up and down, and the actuator (6)
It was supported so that it could reciprocate horizontally along (7). Then, the L-shaped frame (4) is provided on an L-shaped frame support shaft (15), which will be described later, provided at the tip of an arm (10) having a plurality of joints, via a brake (b ₄ ). It was mounted rotatably around its axis.

For details of the arm (10) described above, refer to the first arm around the axis of the vertical axis provided on the support table (16) standing on the work floor (L).
(11) is rotatably supported, and the second arm (12) is rotatably supported around the axis of the vertical axis on the free end side of the first arm (11). A third arm (13) is rotatably supported around the axis of the horizontal shaft on the free end side, and a link is provided between the free end side of the second arm (12) and the free end side of the third arm (13).
A balance spring (S) having an elastic force capable of balancing the weight of the actuator (3) and the L-shaped frame (4) while installing (14)
The L-shaped frame supporting shaft (15) for supporting the L-shaped frame (4) at the tip of the third arm (13) so as to be swingable.
A brake (b ₁ ) is supported on the first arm support part, a brake (b ₂ ) is supported on the second arm (12) support part, and a third arm (13) is supported as a joint part of the arm (10) composed of these components. Brake (b
₃ ) is attached to each.

Therefore, if the braking force of each brake is released, the arm (10)
While the arm (10) can be bent, the arm (10) is maintained in the bent state when each brake is actuated to lock each support portion. Further, the bending operation of the arm (10) does not require such a strong acting force due to the elastic force of the balance spring (s).

Further, the torch (1) is freely reciprocated in the vertical and horizontal directions by the actuators (5) and (6), and such reciprocal movement is performed by a controller (not shown).

That is, the teaching of the position of the torch (1) before the start of cutting and the position after the cutting of the feeder (w ₁ ) etc. of the cast product (w) as the material to be cut by operating each arm in advance. A storage / reproduction device that stores and reproduces an operation, that is, a so-called well-known CPU is used. In addition, the control method of keeping the distance between the tip of the torch (1) constant and keeping the arc length at a constant length changes the arc voltage because the arc length changes almost in proportion to the arc voltage. It is detected and moved up and down so that the arc voltage becomes constant. In other words, when the torch (1) approaches the cutting site, the arc voltage drops, so the torch is kept at the specified voltage.
While raising (1), the arc voltage rises when the torch (1) moves away from the cutting site.
This is to lower (1).

Hereinafter, the operation mode of the plasma arc cutting device will be described. When positioning the torch (1) at a predetermined position above the casting (w) to cut the riser (w ₁ ), each brake
Release the braking of (b ₁ ), (b ₂ ), (b ₃ ), (b ₄ ), (b ₅ ) and apply a force to the torch (1), and this acting force causes the arm (10) to move. By bending and stretching, the casting (w) is positioned at the cutting portion of the feeder (w ₁ ) to be cut, and the torch (1) is easily set at the cutting portion by operating each brake. Then, the position of the torch (1) before cutting is determined on the cutting line of the cast product (w) and the cutting is started. Then, the torch (1) moves at a predetermined speed in the direction taught in advance and reaches the cutting portion, and at the same time, it shifts from the pilot arc to the main arc and the so-called piercing for the plasma airflow to make a cutting thread. During the time, the torch (1) is stopped by the timer for a predetermined period of time.

On the other hand, the cutting distance is detected by the arc voltage, and the torch (1) is moved up and down until the proper distance is reached, and after this piercing time, the torch (1) continues to perform plasma cutting. The cast product (w) is moved, and the height of the cast product (w) moves up and down in accordance with the change, and crosses the cutting portion. The vertical movement of the torch (1) as described above is based on the detection signal detected by the arc length detection device, and the distance D between the tip of the torch (1) and the cutting portion is D.
Is controlled to be constant throughout the movement.

As described above, according to the plasma arc cutting device having the above-described configuration, the torch (1) has the same shape as the cast product (w) even if the feeder (w ₁ ) to be cut of the cast product (w) has irregularities. Since the feeder part (w ₁ ) is traversed while moving up and down according to the unevenness, the work efficiency of the cutting work is greatly improved.

Moreover, since the arm itself is not controlled to be actuated unlike a robot having a known configuration, the actuation of only the actuating device is controlled, so that the control mechanism and the structure are simple and economically disadvantageous. Is rarely.

The above-described embodiment is only one specific example of the present invention, and therefore, the scope of the technical idea of the present invention is not limited by the embodiment.

[Effect of device]

According to the plasma cutting apparatus of the present invention, the torch is stopped for a predetermined piercing time by simply storing the cutting operation range in the storage / reproducing apparatus, and the cutting portion is moved up and down according to the unevenness of the material to be cut. Therefore, even if there are irregularities that could not be cut with the conventional plasma cutting device, it is possible to cut even if it has versatility, and also release the braking device and move the torch. Since the torch can be set just by performing the cutting and the cutting range can be easily set, the time required for the setting can be greatly shortened as compared with the case of the conventional cutting device.

Therefore, according to the present invention, it is possible to realize a highly versatile and extremely useful plasma cutting apparatus that can be used for cutting the feeder and runner even if the material to be cut has a complicated shape.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory view of the plasma cutting apparatus of the present invention, FIG. 2 is a front view of the configuration of the torch moving part of FIG. 1, and FIG.
The figure is a perspective view of a conventional plasma cutting apparatus. (1) ... Torch, (2) ... Holder, (3) ... Actuator, (4) ... L-shaped frame, (5), (6) ... Actuator, (7) ... Shaft, (10) ... Arm, (14) ... link, (b) ... brake, (s) ... balance spring, (w) ... cast product.

Claims (1)

[Scope of utility model registration request] 1. An arm, which is rotatably supported around a vertical axis, has a plurality of joints, and includes a braking device at the rotation support section and the joint section, and rotates about the axis at the tip of the arm. A frame body that supports a support body that is freely supported and that supports a plasma torch so as to move vertically and horizontally, an operating device that operates the support body, and a start and end of cutting of a material to be cut by the plasma torch. Control based on an operation signal from a storage / reproducing device that stores the position teaching operation and a stop signal from a timer that stops the movement of the support for a predetermined period after the transition from the pilot arc to the main arc. And a control device for controlling the distance between the tip of the plasma torch and the material to be cut based on an arm length signal from a detection unit for detecting Plasma cutting device.