Method for cutting riser and riser

Abstract

To provide a feeding head cutting method which can surely cut a feeding head using a feeding head cutting device for automatically cutting a feeding head, and a feeding head.SOLUTION: A feeding head cutting method for cutting a feeding head after a molten metal is injected into a mold and is cast includes the steps of: preparing a feeding head cutting device for automatically cutting a feeding head by a cutting torch; making a notch part where flame from the cutting torch of the feeding head cutting device is concentrated be present in a feeding head cutting starting part; preheating the feeding head cutting starting part by flame of the cutting torch; and moving the cutting torch and cutting the feeding head, after preheating.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for cutting a riser attached to a casting, and to the riser. [Background technology]

[0002] Castings are produced by pouring molten metal into a mold. In order to prevent casting defects such as shrinkage cavities that occur in the product due to solidification and shrinkage of the molten metal, a riser may be provided to replenish the molten metal in the product part of the casting.

[0003] The feeder is cut off using a burner or the like after the molten metal has solidified. However, manual work requires skill and takes a great deal of time, so Patent Document 1 proposes a feeder cutting device (robot) that automatically cuts the feeder.

[0004] The feeder cutting device of Patent Document 1 includes a gas cutting torch, a moving device for moving the cutting torch, and a control device for controlling the moving operation of the moving device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5960591 Summary of the Invention [Problem to be solved by the invention]

[0006] In the feeder cutting device of Patent Document 1, the movement operation of the moving device is appropriately controlled to cut off the feeder, but cutting may fail because the feeder cannot be sufficiently preheated at the starting point of the feeder cutting.

[0007] The present invention aims to provide a feeder cutting method and a feeder that can reliably cut a feeder using a feeder cutting device that automatically cuts the feeder. [Means for solving the problem]

[0008] The present invention provides the following means (1) to (10).

[0009] (1) A method for cutting a riser after pouring molten metal into a mold and casting, comprising the steps of: providing a feeder cutting device for automatically cutting the feeder with a cutting torch; The cutting torch of the feeder cutting device is configured so that the flame from the cutting torch of the feeder cutting device is concentrated on the cutting start portion of the feeder. Formed into shape A step of forming a cutout portion; preheating the cut start portion of the feeder head with a flame of the cutting torch; After preheating, moving the cutting torch to cut off the feeder; A method for cutting a riser, comprising the steps of:

[0010] (2) The method for cutting a feeder head according to (1), characterized in that the feeder head is cylindrical.

[0011] (3) The cutout portion is formed in a cross section of the feeder head so as to have a sector shape from the center to the outer periphery, and the central angle of the sector shape is The angle is 120° or less. (2) The method for cutting the riser described in claim 1.

[0012] (4) The method for cutting a feeder head according to (1), characterized in that the preheating step comprises preheating the feeder head to a temperature at which the feeder head melts.

[0013] (5) The feeder cutting method according to (4), wherein the flame emitted from the cutting torch during the preheating step is formed by supplying a combustion gas.

[0014] (6) When the metal material constituting the molten metal is an iron-based material, in the cutting step, oxygen gas is supplied to a cutting portion in addition to the combustion gas supplied in the preheating step, The feeder cutting method according to (5), characterized in that the supply of the oxygen gas is started when the temperature at which the surface of the feeder melts or a temperature just before that has been reached by preheating in the preheating step.

[0015] (7) The feeder cutting method described in (1), characterized in that the feeder cutting apparatus has a moving device which moves the cutting torch freely in three-dimensional space, the moving device has at its tip a swivellable head portion to which the cutting torch is attached, and the head portion is swivelled during the preheating step. (8) A casting that is cast by pouring molten metal into a mold and is cut by a cutting torch. Disconnected A riser, The above A cutting torch is provided so that a flame from the cutting torch is concentrated at a cutting starting point portion to be cut by the cutting torch. Formed into shape The cutout part exist A riser characterized by:

[0016] (9) The feeder according to (8), characterized in that it is cylindrical.

[0017] (10) The cutout portion is formed in a cross section of the feeder head so as to have a sector shape from the center to the outer periphery, and the central angle of the sector shape is The angle is 120° or less. (9) The riser described in. Effect of the Invention

[0018] According to the present invention, there is provided a feeder cutting method and a feeder that can reliably cut a feeder using a feeder cutting device that automatically cuts the feeder. [Brief description of the drawings]

[0019] [Figure 1] 1 is a flow chart showing a method of cutting a feeder according to an embodiment of the present invention; [Diagram 2] FIG. 1 is a side view showing an example of a feeder cutting apparatus used in carrying out a feeder cutting method according to one embodiment of the present invention. [Diagram 3] FIG. 2 is a perspective view specifically showing a riser having a cutout portion. [Figure 4] FIG. 2 is a cross-sectional view showing a cut-out portion of the feeder. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In this embodiment, the riser is cut off after the molten metal is poured into the mold and cast. The metal material constituting the molten metal poured into the mold is not particularly limited, but an example is an iron-based material such as cast steel.

[0021] FIG. 1 is a flow chart showing a method of cutting off a feeder according to one embodiment of the present invention. The feeder cutting method of this embodiment comprises the steps of: preparing a feeder cutting device (robot) which automatically cuts the feeder using a cutting torch (ST1); creating a cut-out portion at a position corresponding to the feeder cutting start point so that the flame from the cutting torch of the cutting device will be concentrated; pre-heating the feeder cutting start point using the flame from the cutting torch (ST3); and, after pre-heating, moving the cutting torch to cut the feeder (ST4).

[0022] As shown in FIG. 2, the feeder cutting apparatus 10 in ST1 has a cutting torch 1, a moving device 2, and a control device 3.

[0023] The cutting torch 1 cuts the riser head by emitting a flame from a combustion gas. Examples of the combustion gas that can be used include city gas, acetylene gas, propane gas, and a mixed gas of hydrogen gas and a hydrocarbon gas. Examples of the mixed gas of hydrogen gas and a hydrocarbon gas include a mixed gas of hydrogen gas and an ethylene gas. The mixed gas of hydrogen gas and a hydrocarbon gas has a high thermal energy density due to a high linearity of the flame compared to city gas and the like, and has a low radiant heat, so that the local amount of heat required for cutting increases, and it is possible to perform high-speed and flat cutting. In addition, the mixed gas of hydrogen gas and a hydrocarbon gas can reduce the amount of CO2 generated per unit volume of the combustion gas compared to other gases such as city gas. In the mixed gas of hydrogen gas and a hydrocarbon gas such as ethylene gas, the ratio of hydrogen gas may be 30 to 70 vol%, for example, 60 vol%.

[0024] The moving device 2 is for freely moving the cutting torch 1 in three-dimensional space, and in the example of Fig. 2, the moving device 2 has a multi-joint structure, and the cutting torch 1 is attached to the head at the tip of the moving device 2. The head can be swung via the joint, and may be swung during preheating. This allows the flame to effectively reach the location that needs preheating when preheating the cutout.

[0025] The control unit 3 controls the movement of the cutting torch 1 by the movement device 2, and also controls the on / off of the flame from the cutting torch 1, the flow rate of gas, and the like.

[0026] In the feeder cutting apparatus 10, the cutting torch 1 is positioned by the moving device 2 at a position corresponding to the cutting point of the feeder 21 attached to the casting 20, and the feeder 21 is cut by moving the cutting torch 1 by the moving device 2 while a flame from the cutting torch 1 is radiated to the cutting point of the feeder 21.

[0027] In ST2, a cutout portion is provided at a position corresponding to the cutting start point of the feeder head so that the flame from the cutting torch of the cutting device is concentrated. This is for the following reason.

[0028] A feeder is attached to the product part of a casting to prevent casting defects such as shrinkage cavities that occur in the product due to solidification and shrinkage of the molten metal when molten metal is poured into a mold to produce a casting, and supplies the molten metal to the product part. After the molten metal solidifies, the mold is removed to obtain the casting, but since the solidified feeder is attached to the casting, the feeder is cut and removed.

[0029] When cutting a feeder head with a cutting torch, it is necessary to sufficiently preheat the cutting start part of the feeder head before moving the cutting torch to cut it. However, if the feeder head is cylindrical, for example, the flame of the cutting torch may escape in the circumferential direction even if it is applied to the cutting start part of the feeder head, making preheating difficult. Even if the feeder head has such a shape that preheating is difficult, when a skilled worker performs the cutting work, the cutting start part of the feeder head can be properly preheated by adjusting the flame position of the cutting torch, and the feeder head can be properly cut. However, when cutting a feeder head is automatically performed by a feeder head cutting device (robot), the flame position of the cutting torch cannot always be properly adjusted, and the cutting torch may be moved without sufficient preheating, resulting in failure to cut the feeder head. By oscillating the head, the flame can be effectively delivered to the part that needs preheating, but there are still cases where the preheating is insufficient.

[0030] Therefore, in this embodiment, a cutout portion is provided at the cutting start point of the feeder head so that the flame from the cutting torch of the cutting device can be concentrated. Specifically, as shown in Figure 3, a cutout portion 22 is provided at a position corresponding to the cutting start point of the base end of a feeder head 21 attached to a casting 20 so that the flame from the cutting torch can be concentrated. This allows the flame from the cutting torch to be concentrated at the cutting start point during preheating, as described below, and sufficient preheating can be performed.

[0031] The shape of the cutout portion 22 is not particularly limited as long as it is a shape that allows the flame from the cutting torch to be concentrated. The angle θ of the cutout portion 22 shown in Fig. 4 is preferably 120° or less, and more preferably 90° or less.

[0032] The cutout portion of the riser can be provided by forming a cutout portion of the same shape in the corresponding portion of the wooden pattern, which is the original form of the mold.

[0033] In the preheating step ST3, for example, a flame from the cutting torch is irradiated onto the cutting start point of the feeder head with the cutting torch stopped or with the head swivelled, to preheat the feeder head to a temperature at which it melts. At this time, as described above, the flame can be concentrated on the cutout portion, so sufficient preheating can be achieved.

[0034] In the cutting process of ST4, the cutting torch is moved and the heat of the flame cuts the feeder head, while the cutting start point of the feeder head is sufficiently heated by the preheating in ST3. At this time, the feeder head is heated to a sufficiently high temperature by the preheating, so that the feeder head can be cut appropriately.

[0035] When the metal material to be cast is an iron-based material such as cast steel, it is necessary to oxidize it when cutting, so oxygen gas is supplied to the cutting point in addition to the combustion gas. At this time, it is preferable that the supply of oxygen gas starts when the temperature at which the feeder surface melts due to preheating in ST3 or a temperature just before that, for example, 1550°C, is reached. If the timing of supplying oxygen gas is too early, a large amount of oxygen gas will be wasted. It is preferable that the timing of supplying oxygen gas is determined in advance for each product and programmed into the control unit 3.

[0036] According to this embodiment, the feeder can be reliably cut off using a feeder cutting device that automatically cuts off the feeder.

[0037] Although the embodiments of the present invention have been described above, these are merely examples and should not be considered as limiting. The above embodiments may be omitted, substituted, or modified in various ways without departing from the gist of the present invention.

[0038] For example, in the above embodiment, an example was shown in which the cutting torch was moved using an articulated type moving device as shown in FIG. 2, but the present invention is not limited to this. [Explanation of symbols]

[0039] 1 cutting torch 2. Mobile Devices 3. Control Unit 10. Feeder cutting device (robot) 20 Casting 21. Riser 22 Cutout part

Claims

1. A method for cutting a riser after casting by pouring molten metal into a mold, comprising the steps of: providing a feeder cutting device for automatically cutting the feeder with a cutting torch; providing a cutout portion at a cut-off starting point of the feeder head such that a flame from the cutting torch of the feeder head cutting apparatus is concentrated thereon; preheating the cut start portion of the feeder head with a flame of the cutting torch; After preheating, moving the cutting torch to cut off the feeder; A method for cutting a riser, comprising the steps of:

2. 2. The method according to claim 1, wherein the feeder is cylindrical.

3. A method for cutting a feeder as described in claim 2, characterized in that the cutout portion is formed in a fan shape from the center to the outer periphery in the cross section of the feeder, and the central angle of the fan shape is 120° or less.

4. 2. The method according to claim 1, wherein the preheating step comprises preheating the feeder to a temperature at which the feeder melts.

5. 5. The method according to claim 4, wherein the flame emitted from the cutting torch during the preheating step is formed by supplying a combustion gas.

6. When the metal material constituting the molten metal is an iron-based material, in the cutting step, oxygen gas is supplied to a cutting portion in addition to the combustion gas supplied in the preheating step, The feeder cutting method according to claim 5, characterized in that the supply of the oxygen gas is started when the temperature at which the surface of the feeder melts or a temperature just before that has been reached by preheating in the preheating step.

7. The feeder cutting method according to claim 1, characterized in that the feeder cutting apparatus has a moving device which moves the cutting torch freely in three-dimensional space, the moving device having at its tip a swivellable head portion to which the cutting torch is attached, and the head portion is swivelled during the preheating step.

8. A riser that is attached to a casting that is cast by pouring molten metal into a mold and is cut off by a cutting torch, A feeder head characterized in that a cut-out portion formed in a shape such that a flame from the cutting torch is concentrated at a cut-starting portion cut by the cutting torch.

9. 9. A feeder according to claim 8 which is cylindrical.

10. A feeder as described in Claim 9, characterized in that the cutout portion is formed so as to be fan-shaped from the center to the outer periphery in the cross section of the feeder, and the central angle of the fan shape is 120° or less.

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