JPS626770A - Pouring method by robot for casting - Google Patents

Abstract

PURPOSE:To prevent the intrusion of foam and oxide films into a casting product by controlling the tilting angle of a vessel for pouring as an end effecter with time according to a pouring pattern thereby smoothly changing the pouring rate during pouring. CONSTITUTION:A multijoint robot RB for casting having 5 degrees of freedom is constituted by providing a swiveling base 2 on a base plate 1, horizontally and pivotally supporting the 1st-3rd arms 3-5 successively thereto and vertically and pivotally supporting a turning body 6 mounted with a ladle 7 which is a pouring vessel as the end effecter to the 3rd arm 5. The above-mentioned robot RB is operated to ladle the molten metal from a crucible into the ladle 7 and thereafter the ladle 7 is moved over a prescribed pouring port and is tilted to pour the molten metal into the pouring port. The above-mentioned pouring is executed by setting the pattern of the transition of the pouring rate with time from the capacity, shape, etc. of the casting mold and controlling the tilting angle of the ladle 7 with time in accordance with the pattern obtd. in the above-mentioned manner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a pouring method using a casting robot.

[Prior art]

With factory automation, casting work is also being automated. In die-casting, various mechanisms such as link mechanisms have already been used to automate the process from drawing hot water to pouring the metal, with some success.

However, when it comes to gravity casting, there is no automated method for pouring, which is a major part of producing high-quality castings.

[Problem to be solved]

Regardless of the casting method, such as die casting or gravity casting, the introduction of air bubbles or oxide film into the molten metal due to rapid pouring will lead to a decrease in product quality, but it is not possible to simply pour the metal sequentially. If this is done, the contamination of air bubbles and oxide film cannot be avoided. This is a particular problem in gravity casting, which requires the production of high-quality castings, and is actually compensated for by the skill of the operator. By the way, in order to prevent air bubbles and oxide film from getting mixed in when pouring, during the pouring period,
It is necessary to smoothly change the amount of poured metal, and automation that addresses this point is desired. Although this is a particular problem in gravity casting, it can be seen as a general problem in pouring in die casting and other castings.

[Means for solving problems]

In this invention, a preferable pattern (pouring pattern) of the amount of molten metal over time determined by the amount of molten metal poured into the mold, the capacity of the pouring container such as a ladle or tripe, the casting material, etc.
is determined, and along this, a pattern of smooth temporal changes in the inclination angle of the pouring container is determined. Then, based on the pattern of changes in the inclination of the pouring container, the casting robot is taught the pouring operation and reproduced.

[For production]

Since the inclination angle of the pouring container is changed smoothly over time, the pouring amount changes smoothly without sudden changes. This prevents air bubbles from entering the molten metal poured into the mold, and the oxide film poured into the mold also floats as a supernatant, so it is not mixed into the product. Therefore, high quality products can be produced.

〔Example〕

An embodiment in which a ladle is used as an end effector of a five-axis articulated robot and molten metal drawn from a crucible is poured into four casting machines will be described with reference to FIGS. 1 to 7.

The articulated robot) RB shown in FIG.
A second arm 4 is horizontally supported by the first arm 3, a third arm 5 is horizontally supported by the second arm 4, and a ladle 7 is vertically supported by the third arm 5.
It has 5 degrees of freedom due to the rotating body 6 with salt 9 attached.

Then, as shown in FIG. 2, a first casting machine 9 and a second casting machine 10 are arranged on one side of a circular arc centered on the rotation center 2a of the turning table 2, with the crucible 8 in the center. An eighth casting machine 11 and a fourth casting machine 12 are disposed on the other side, and the centers of the sprues 9a, 10a, 11a and 12a of each casting machine are arranged at approximately equal distances from the rotation center 2a. It is set up. Although it is not necessarily necessary to arrange the casting machine in this way,
Desirable as it is very efficient. A residual metal reservoir 13 is provided on the side of the crucible 8 facing the casting robot RB. Furthermore, a safety fence 14 having a door (not shown) is placed around this area.
A control device 15 and an air conditioner 16 are arranged at a position away from the crucible 8.

Further, the casting robot RB does not necessarily need to have five degrees of freedom, and only needs to have at least four degrees of freedom, but one with five degrees of freedom is convenient. In addition, in order to prevent the robot RB from absorbing radiant heat from the molten metal pumped into the crucible 8 and the ladle 7, the second arm 4 is covered with a force reflector 4a as shown in FIG. 7 is supported by the rotating body 6 via a heat insulator (not shown). Furthermore, in order to suppress temperature rise,
A blower 4b is attached to the base of the second arm 4, and a ventilation path 4d having a heat dissipating vertical fin 4c is provided in the second arm 4, and ventilation is carried out through a ventilation hole 4e provided around the 4° tip of the second arm. It is.

The casting robot RB is shown in the robot symbol as shown in Fig. 4, and has a rotating body 2, 6 arms 3, 4, 5, and a rotating body 6.
A series of operations such as drawing hot water and pouring hot water are performed by controlling the rotation angles α1 to α5.

The control device 15 includes a computer 17. which includes a microprocessor, memory, etc. (not shown). Bus 18 Although details are not shown, an operation unit 19 is provided with operation switches for controlling joint angles α1 to α5, switches for teaching operations, etc.
As shown in FIG. 5, driving parts Sα1 to Sα5 . Casting machine 9-12. It is connected to a hot water level sensor 20 whose details are not shown.

Casting robot) RB is initially in the home position,
The ladle 7 is located at the home position HP, but it is activated by an interlock signal from one of the casting machines, moves to the crucible 8 according to the instructions, draws hot water according to the instructions, and receives the interlock signal. Move to the casting machine where it was generated and pour the metal using the instructed movements. Then, it moves to the top of the remaining hot water reservoir 13, drains the hot water, and returns to the home position HP. At this time, if an interlock signal is generated from the next casting machine, the same operation is performed to pour the metal into that casting machine. Depending on the capacity of the molds, it is also possible to pump hot water for two molds in one go and pour the hot water into two casting machines in sequence. Further, the number of casting machines is not limited to four, and an appropriate number can be provided, and an appropriate program can be set.

When teaching pouring, the pattern of the amount of poured metal over time is determined, for example, as shown in FIG. 6, based on the capacity, shape, etc. of the mold. On the other hand, the pattern of the temporal change in the inclination angle of the ladle 7 is determined from the relationship between the inclination angle of the ladle 7 and the amount of discharged hot water, as shown in FIG. 7, for example.

From the pattern shown in FIG. 7, it is possible to know how many angles of ladle inclination should be given at appropriate time pitches (for example, 0.2 seconds) during the pouring time.
After the ladle 7 is moved onto the sprue 9a of the mold by operating the operating switch, the teaching switch on the control device 15 is pressed and the operating switch for the ladle 7 is operated to tilt the ladle 7. During this time, the rotation angle α5 is set at an appropriate time pitch.
The teaching is completed by importing the data.

If the positions of the sprue 9a and the pouring port of the ladle 7 shift as the ladle inclination fluctuates, operate other operation switches during the above-mentioned teaching or during playback for a test after the teaching. Correct the spout position by moving the , and teach this as well. Also, first place the ladle 7 on the sprue 9a.
When positioning the pouring spout of
Position dollar 7. In addition, when changing the inclination angle of the ladle 7, in order to keep the height of the pouring port of the ladle 7 constant with respect to the sprue 9a, the ladle 7 is moved vertically by operating an operation switch such as another arm. I will also teach you about this. After teaching, a playback operation may be performed for testing and the teaching content may be modified.

Such a teaching operation can be performed not only on the sprue of the casting machine, but also on a separate mock-coagulation sprue, or using water or the like as a dummy material. The pattern of the amount of poured metal over time is not limited to that shown in Figure 6.
There are other things you can decide. Therefore, the pattern of the temporal change in the ladle inclination angle can be determined in various ways.

[Effects of the Invention] According to the present invention, when a casting robot pours metal into a mold, the amount of metal poured into the mold can be smoothly changed. There is no possibility of contamination. Therefore, high-quality castings can be produced, which is very effective in automating casting operations.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic diagram, FIG. 2 is a layout diagram, FIG. 3 is an arrow view, FIG. 4 is a robot symbol diagram, and FIG. 5 is a block diagram. , Figures 6 and 7
The figure is a diagram. In the drawings, RB is a casting robot, 7 is a ladle (container for pouring metal), and θ is a ladle inclination angle (container inclination for pouring metal).

Claims (4)

[Claims] (1) A pouring method using the casting robot, which comprises temporally controlling the inclination of the pouring container of the casting robot, which is equipped with a pouring container as an end effector, based on a pouring pattern. . (2) The pouring method using a casting robot according to claim 1, wherein the pouring pattern is a transition pattern of pouring amount with respect to pouring time. (3) When controlling the inclination angle of the molten metal pouring container, the molten metal pouring position of the molten metal pouring container is to be controlled.
Pouring method using a casting robot as described in Section 1. (4) A casting robot according to claim 1, which is configured to control the distance between the spout of the pouring container and the sprue of the mold when controlling the inclination angle of the pouring container. Pouring method.