JP7211093B2 - Casting sand removal method and device - Google Patents

Description

The present invention relates to sand removal method and apparatus.

Conventionally, after pouring molten metal into the mold and cooling it, the mold is separated from the mold sand in order to take out the casting product. There is a method in which the mold conveyed above is placed on a vibrator, and the mold is broken and separated by vibration. However, in a product having a structure including holes, it is difficult to completely remove the sand in the holes by the above method.

In Patent Document 1, as a workpiece having a structure including a hole, a plurality of grooves are provided in the inner surface of the hole extending in one direction, and are spaced apart in the axial direction of the hole and recessed in the direction perpendicular to the axis of the hole. Discloses the sand removal of the work provided with. This workpiece is rotated around the axis of the hole, a nozzle is inserted into the hole, and the injection material is injected from the nozzle tip in the circumferential direction to remove the core sand in each groove.

In Patent Document 2, a rod-shaped member having a protrusion formed at the far end of a hole is inserted into a workpiece having the same configuration as the above, a nozzle is positioned on the opposite side of the hole, and an injection material is injected from the nozzle into the hole. The injection material hits the inclined surface at the tip of the rod-shaped member, the injection material hitting the inclined surface is reflected by the grooves on the side, and the rod-shaped member is advanced and retreated to form a plurality of grooves in each hole. A method for removing core sand within is disclosed.

In Patent Document 3, an air blast device having a plurality of injection nozzles corresponding to the plurality of holes provided in the work is provided, and a constant amount of air is blown from the tip of the injection nozzle to the plurality of holes of each work A method of injecting the injection material into each hole of the workpiece while rotating the injection nozzle at an angle is disclosed.

In Patent Document 4, a workpiece similar to that described in Patent Document 1 is gripped by a robot arm, while a nozzle that injects an injection material is held at a fixed position, and the robot arm is moved to the nozzle. By inserting a nozzle into the hole of the gripped work, rotating the nozzle, and changing the position of the work in the direction of the nozzle, the core sand inside the expanded diameter is removed.

JP-A-9-314469 JP-A-10-166137 JP 2004-106092 A JP 2014-42976 A

In the above patent documents 1 to 4, the hole formed in the work is a hole extending linearly in one direction, and the position of the nozzle in the hole is relatively aligned in the direction in which the hole extends. It is moved to perform blasting by injecting an injection material or the like onto the sand or the like adhering to the grooves of each of the plurality of enlarged diameter portions.
Therefore, when the hole formed in the work is bent in the middle, the devices described in the respective documents do not have a configuration for removing the molding sand adhering to the bent portion. SUMMARY OF THE INVENTION The present invention provides a method and apparatus for removing sand adhering to a bent portion of a hole formed in a work without damaging the work. In the present invention, "damage to the work" includes "thinning of the inner surface of the hole of the work, deviating from the design dimension standard".

In order to solve the above problems, the present invention employs the following means.
That is, the casting sand removal method of the present invention is a method for removing casting sand from a hole having a bent portion, in which a nozzle is inserted into the hole, and the tip of the nozzle is positioned with a gap with respect to the casting sand. and starting to inject the injection material from the nozzle, starting to withdraw the nozzle from the hole after a first period of time has passed since the injection was started, and then moving the nozzle to the hole over a second period of time. characterized by pulling out from
According to such a configuration, it is possible to efficiently remove molding sand remaining in the bent portion.

In one aspect of the present invention, the injection amount of the injection material is controlled based on the hole diameter and the nozzle diameter.
According to such a configuration, it is possible to set an appropriate injection amount.

In one aspect of the present invention, the first time and the second time are set based on the hole diameter, the nozzle diameter, and the shape of the bent portion.
According to such a configuration, it is possible to set an appropriate time.

One aspect of the present invention is characterized in that the nozzle is a straight nozzle.
With such a configuration, the present invention can be properly implemented.

A casting sand remover of the present invention is a casting sand remover for removing casting sand present in a work having a hole having a bent portion, wherein the work is removed from a position where the hole is defined. a robot arm having a nozzle for injecting an injection material; an injection mechanism including the nozzle for injecting the injection material from the nozzle; the robot arm; and the injection mechanism wherein the control unit controls an insertion operation of the nozzle into the hole, an injection operation of the injection mechanism, and an extraction operation of the nozzle.
According to such a configuration, it is possible to efficiently remove molding sand remaining in the bent portion.

Advantageous Effects of Invention According to the present invention, it is possible to provide a method and apparatus for removing sand adhering to a bent portion without damaging a work.

1 is a schematic diagram showing a schematic configuration of a casting sand remover according to the present embodiment; FIG. It is a schematic diagram which shows the procedure which removes a casting sand with the said casting sand remover. It is a schematic diagram which shows the procedure which removes a casting sand with the said casting sand remover. It is a schematic diagram which shows the procedure which removes a casting sand with the said casting sand remover. It is a schematic diagram which shows the procedure which removes a casting sand with the said casting sand remover. It is a schematic diagram which shows the procedure which removes a casting sand with the said casting sand remover. FIG. 4 is a schematic diagram for explaining time control when sand is removed by the sand remover. FIG. 4 is a schematic diagram for explaining time control when sand is removed by the sand remover. FIG. 4 is a schematic diagram for explaining injection material control when sand is removed by the sand remover. FIG. 4 is a schematic diagram for explaining injection material control when sand is removed by the sand remover. FIG. 4 is a schematic diagram for explaining injection material control when sand is removed by the sand remover.

Hereinafter, the casting sand removing method and apparatus according to the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a casting sand remover according to the present embodiment. FIGS. 2 to 6 are schematic diagrams for explaining the steps of the casting sand removing method according to the present embodiment, showing a cross-sectional view of the workpiece W and the nozzle 12. FIG.
As shown in FIG. 1, the casting sand remover 1 of this embodiment includes a support base 11 that supports a workpiece W having a hole with a bent portion, a robot arm 13 that has a nozzle 12, and a nozzle 12. It has an injection mechanism 14 and a control unit 15 .

The workpiece W is fixed and supported on the support table 11 by a fixing jig (not shown) so that the holes 16 of the workpiece are positioned at predetermined positions. The work W is fixed on the support base, and control such as confirmation of whether or not it is securely fixed is executed by communication with the control unit 15 via a communication path (not shown).
The injection mechanism 14 includes a nozzle 12 , a hose 18 connected to the nozzle 12 for pumping an injection material 17 to the nozzle 12 , and a tank 19 of injection material. The nozzle 12 is supported by the robot arm 13 and configured to be freely positioned with respect to the work W. As shown in FIG. The control unit 15 communicates with the robot arm 13 and the injection mechanism 14 via the communication path 1T, and controls the insertion operation of the nozzle 12 into the hole 16, the injection operation of the injection mechanism 14, and the withdrawal operation of the nozzle 12. do. A series of mutual operations of the support table 11, the robot arm 13, and the injection mechanism 14 are controlled by the control unit 15 according to a predetermined program.

The workpiece W is a casting product, which is taken out from the mold of the casting equipment, and is transported to the support base 11 after the sand on the surface is roughly removed by vibration of the shakeout machine or shot material shot by the shot blasting machine. be done.
Referring to FIG. 2, the work W is a block having a certain size and has a hole 16 communicating between surfaces 2a and 2b. The hole 16 has a circular cross-section and has a linear portion 21 extending from the surface 2a toward the surface 2b by a dimension L substantially perpendicular to the surface 2a. The straight portion 21 is connected to a bent portion 22 that bends downward in the figure at an angle θ from the straight straight line when it has progressed by the dimension L. As shown in FIG. The bent portion 22 is connected to a straight portion 23 which extends in the same direction as the first straight portion 21 and extends toward the surface 2b after proceeding by a dimension M. As shown in FIG.

On the other hand, a linear portion 24 extending in the direction of the surface 2a is formed from the surface 2b. A straight portion 25 extending downward in the drawing is formed in the middle of the straight portion 24 . The straight portion 25 merges with the straight portion 23 on the way.
As described above, this workpiece W has undergone a step of removing external molding sand after casting. There is molding sand S (for example, core sand) that cannot be removed by projecting shot material from the outside.

Next, a method for removing the molding sand S in the hole 16 using the device configured as described above will be described.
Referring to FIG. 2, as described above, in the workpiece W, the molding sand S that could not be removed in the previous step of removing the molding sand from the surface of the casting product exists in the bent portion 22 and the straight portion 23. As shown in FIG. After confirming that the workpiece W is fixed on the support table 11 , the control unit 15 instructs the robot arm 13 to perform the positioning operation of the nozzle 12 . Upon receiving a command, the robot arm 13 inserts the held nozzle 12 into the hole 16 of the workpiece.

The robot arm 13 positions the tip 2N of the nozzle 12 in the straight portion 21 of the hole 16 with a gap K from the surface 2S of the molding sand S. This positioning may position the nozzle 12 at the same position every time based on the position data of the surface 2S of the molding sand S accumulated in advance from the measurement of a plurality of samples. Alternatively, a pressure sensor (not shown) of the robot arm 13 detects that the tip 2N of the nozzle 12 abuts the surface 2S of the molding sand S when the nozzle 12 is inserted, and from that position, the pressure sensor moves in the direction opposite to the molding sand S. Alternatively, the nozzle may be positioned by retracting the nozzle by a gap K.

Referring to FIG. 3, when nozzle 12 is positioned as described above, controller 15 instructs injection mechanism 14 to inject injection material 17 . The injection mechanism 14 pumps the injection material 17 from the tank 19 to the nozzle 12 through the hose 18 by fluid pressure such as compressed air, and injects the injection material 17 from the nozzle 12 toward the molding sand S. The controller 15 then maintains that state until the first time elapses.

Referring to FIG. 4, control unit 15 instructs robot arm 13 to start extracting nozzle 12 from hole 16 after the first time has elapsed. The robot arm 13 starts pulling out the nozzle 12 according to the instruction. Subsequently, referring to FIGS. 5 and 6, the controller 15 controls the robot arm 13 to pull out the nozzle 12 from the hole 16 over a second period of time. Robotic arm 13 pulls nozzle 12 out of hole 16 for a second time. After that, the control unit 15 causes the injection mechanism 14 to stop injecting the injection material 17, moves the robot arm 13 to a position (not shown) for exchanging the work W, and releases the work fixing mechanism of the support table. Then, the work W is transferred to the next process, and a series of operations is completed. Workpieces may be exchanged manually or by a dedicated transfer robot.

As described above, in this embodiment, the nozzle 12 is inserted into the hole 16 of the workpiece W to remove the molding sand S from the bent portion 22 in the hole 16 of the workpiece W, and the surface 2S of the molding sand S is removed. Since the injection material 17 is injected with a gap K between the two, the injection material can be injected directly onto the surface 2S of the molding sand S whose surface is hardened, so that the molding sand S on the bent portion 22 can be effectively removed. can do.

In addition, since the injection material 17 is injected to the molding sand S while maintaining the gap K from the injection start until the first time elapses, the injection material 17 is injected to the molding sand S whose surface is hardened. Sufficient time is secured. After the lapse of the first period of time for removing the molding sand S from the bent portion 22, the nozzle 12 is pulled out while the injection material 17 is being injected over the second period of time. As shown in FIGS. 4 to 6, the molding sand S can be efficiently removed without damaging the workpiece while gradually removing the molding sand S as the nozzle 12 retreats. .

In this embodiment, the first time and the second time are set based on the diameter size of the hole 16 of the work W and the nozzle 12 and the shape of the bent portion. When an appropriate time is not set, for example, when the first time is short (FIG. 7), this means a short time including the case where the first time is 0. However, when the injection of the injection material is not stable, Since the extraction is started immediately, the sand hardened on the surface cannot be scraped off and the sand cannot be removed. If the first period of time is too long (FIG. 8), the injection material continues to be injected from the proximal end onto the side wall of the bent portion 22 of the work even after the molding sand S of the bent portion 22 is removed, so that the work W is damaged 81 . will give If the second time is not properly set, it will also cause imperfect removal of molding sand. Therefore, in the present embodiment, it is possible to focus on this important parameter and set an appropriate value, so that it is possible to efficiently remove molding sand from the bent portion without damaging the work.

In this embodiment, the injection amount of the injection material is set based on the diameter size of the hole 16 of the work W and the nozzle 12 . The state inside the hole 16 when the injection material 17 is injected into the hole 16 depends on the amount of the injection material 16 injected into the hole 16 and the amount of the injection material reflected inside the hole 16 and discharged from the hole 16. It can be considered in terms of stationary relations of quantities.
That is, when the injection amount of the injection material 17 is too large (FIG. 9), the amount of the injection material 17 injected into the hole 16 exceeds the amount of the injection material 17 discharged from the hole 16. The hole 16 is completely filled, and the effect of scraping the molding sand S cannot be obtained.
When the injection amount of the injection material 17 is small (FIG. 10), a sufficient amount of the injection material 17 is not injected to the molding sand S, so that the molding sand S cannot be scraped or the grinding speed becomes slow.
When the injection amount of the injection material 17 is properly set (FIG. 11), the amount of the injection material 17-1 injected into the hole 16 and the amount of the injection material 17-2 discharged from the hole 16 are almost equal to each other. A steady state in which the amount is the same is formed, and the molding sand S can be removed efficiently.

In this embodiment, as shown in each figure, the molding sand S is removed using a straight nozzle. Since the hole 16 is connected to the bent portion 22 via the straight portion 21, the injection material 17 can be efficiently pumped by using a straight nozzle, and a gap K from the bent portion 22 is provided. becomes easier.

In the present embodiment, the respective dimensions are, for example, the workpiece hole diameter is Φ8 to Φ20 mm, the nozzle diameter is Φ3 to Φ10 mm, the injection pressure is 0.1 to 0.6 MPa, and the injection material is steel shot Φ0. .125 to Φ1.4 mm may be targeted. For example, the gap K may be set to around 5 mm, or the first time may be set to 1 to 2 seconds, and the second time may be set to 3 to 5 seconds. However, it is not limited to this, and for example, when the target hole diameter is not within the above range, appropriately changed values may be used.

(Modification)
The present invention is applicable to works having various bent portions other than the above embodiments. For example, the present invention includes a case where the curved portion forms a loose curved surface and a case where the inner diameter changes gradually. Based on the shape, the injection amount of the injection material, the first time, and the second time are appropriately set. Also, the nozzle may be rigid or flexible and may be appropriately selected based on the environment of the bend in the bore of the workpiece to be sand removed.

1 Casting sand remover 11 Support stand 12 Nozzle 13 Robot arm 14 Injection mechanism 15 Control unit 16 Hole 17 Injection material 2N Nozzle tip S Casting sand K Gap W Work

Claims (5)

A method for dropping molding sand in a hole having a bent portion, comprising:
insert the nozzle into the hole,
Positioning the tip of the nozzle with a gap with respect to the molding sand,
starting injection of the injection material from the nozzle;
maintaining that state until a first time elapses after starting the injection;
starting to pull out the nozzle from the hole after the first time elapses;
Thereafter, the nozzle is pulled out from the hole over a second period of time while the injection material continues to be injected from the nozzle ,
The first time and the second time are set based on the hole diameter, the nozzle diameter, and the shape of the bent portion,
The injection amount of the injection material is set such that the amount of the injection material injected into the hole and the amount of the injection material discharged from the hole form a steady state. Controlled sand removal method. A method for dropping molding sand in a hole having a bent portion, comprising:
insert the nozzle into the hole,
Positioning the tip of the nozzle with a gap with respect to the molding sand,
starting injection of the injection material from the nozzle;
maintaining that state until a first time elapses after starting the injection;
starting to pull out the nozzle from the hole after the first time elapses;
Thereafter, the nozzle is pulled out from the hole over a second period of time while the injection material continues to be injected from the nozzle,
The first time and the second time are set based on the hole diameter, the nozzle diameter, and the shape of the bent portion,
the first time is set to a time during which the molding sand can be removed from the bent portion, and the second time is set to a time during which the rest of the molding sand can be removed;
The injection amount of the injection material is set such that the amount of the injection material injected into the hole and the amount of the injection material discharged from the hole form a steady state. Controlled sand removal method. 3. The casting sand removing method according to claim 1, wherein an injection amount of said injection material is controlled based on said hole diameter and said nozzle diameter. The casting sand removal method according to any one of claims 1 to 3, wherein the nozzle is a straight nozzle. A casting sand remover for removing casting sand present in a work having a hole having a bent portion,
a support base for supporting the workpiece so that the hole is positioned at a determined position;
a robot arm equipped with a nozzle for injecting the injection material;
an injection mechanism that includes the nozzle and injects an injection material from the nozzle;
The robot arm and a control unit that controls the injection mechanism,
The control unit controls an insertion operation of the nozzle into the hole, an injection operation of the injection mechanism, and an extraction operation of the nozzle,
The control of the robot arm and the injection mechanism by the control unit includes:
inserting the nozzle into the hole;
Positioning the tip of the nozzle with a gap with respect to the molding sand,
starting injection of the injection material from the nozzle;
maintaining that state until a first time elapses after starting the injection;
starting to pull out the nozzle from the hole after the first time elapses;
after that, in a state in which the injection material continues to be injected from the nozzle, the nozzle is pulled out from the hole over a second period of time;
The first time and the second time are set based on the hole diameter, the nozzle diameter, and the shape of the bent portion,
The injection amount of the injection material is set such that the amount of the injection material injected into the hole and the amount of the injection material discharged from the hole form a steady state. and controlling .

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