JP2736139B2 - Frameless casting line - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a frameless casting line, and more particularly, to a frameless casting line capable of taking out a good casting.

[Prior Art] In a conventional frameless casting line, a sand molding machine, a pouring machine, a casting removal device, a sand recovery machine, and the like are arranged along a conveyor device for sand mold conveyance operated at intervals. The working environment is not good from the viewpoint of thermal and dust, and therefore, in recent years, automation of the work is expected.

2. Description of the Related Art Various types of casting removal devices for removing a casting from a sand mold are conventionally known.

Currently used casting unloaders have a drum cooler located at the end of the conveyor device. When a sand mold is put into this rotating drum cooler, the sand mold is separated into casting and sand. In addition, a casting remover which separates a casting from sand by dropping a sand mold on a vibrating sieve provided at the end of the conveyor device is also in practical use.

Further, the apparatus disclosed in Japanese Utility Model Laid-Open Publication No. 63-6146, 163260, 170066, 252666 has a casting take-out device arranged facing the end of the conveyor device, and the casting take-out device is a sand mold portion below the casting. And a pressing arm pierced into a sand mold portion above the casting. At the time of casting removal, after piercing each arm into the sand, both arms are relatively moved in a direction approaching each other to grip the casting vertically, and then both arms are turned or linearly moved in a horizontal plane. To remove the casting.

[Problems to be Solved by the Invention] However, in a casting removal device using a drum cooler or a vibrating sieve, the posture and position of the casting to be removed become insufficient, and the next handling of the casting (for example, placing on a casting conveyor) Operation) could not be automated and had to be performed manually. As a result, the operator has been burdened with a great amount of labor in a poor environment.

The casting removal device disclosed in each of the above-mentioned publications,
It is intended to eliminate the drawbacks of the casting removal device and remove the casting in a fixed posture, but has the following problems.

The first problem is that the sand mold stationary position varies with the interval operation of the conveyor device. That is, the individual sand molds constituting the frameless sand mold row are compressed in the conveyance direction by the impact force at the time of starting and stopping during conveyance. Also, the single travel distance of the conveyor device is not strictly constant, and as a result, the stationary position of the sand mold that has reached below the casting removal device varies. If the rest position of each sand mold under the casting removal device fluctuates, even if the extraction arm is always pierced by a certain depth into the sand mold, the relative position in the transport direction between the extraction arm and the casting will be undefined, and the subsequent handling will be difficult. Disturbance occurs. For example, when placing the extracted casting on a casting conveyor, it is difficult to place the casting without always holding the casting at a fixed position (generally, the tip) of the extraction arm. Further, the casting may be hooked incompletely on the extraction arm in the sand mold, and in this case, the extraction of the casting also fails.

The second problem is that, at the boundary between the individual sand molds constituting the frameless sand mold row, an opening, a shift, a collapse, etc. may occur as shown in FIG. And the extraction arm may fail or the extraction arm may damage the casting.

A third problem is that the casting removal device is configured to grip the casting (particularly its product part) with a large gripping force in the vertical direction and to remove the casting from the sand mold, and the removal arm may damage the casting. That is. If the casting surface to be gripped is not flat in the horizontal direction, or if the area of the casting surface to be gripped is insufficient, the probability increases. Furthermore, when manufacturing various types of castings with different sand molds on the same frameless casting line, it is not easy to grip each casting having a different shape.

The present invention has been made in view of such problems,
It is an object of the present invention to provide a frameless casting line that can reliably remove a casting from a sand mold in a fixed posture that is advantageous for handling and that does not damage the casting.

[MEANS FOR SOLVING THE PROBLEMS] A frameless casting line according to the present invention includes a conveyor device for intermittently transporting a frameless sand mold row composed of a plurality of sand molds connected in a line in a traveling direction and each having a sprue. A casting withdrawing device having a withdrawal arm for withdrawing a casting, the casting withdrawing device being disposed above the end of the conveyor device so as to be movable in the conveying direction, and a state of the upper surface of the sand mold being disposed above the end of the conveyor device. A sand mold upper surface sensor to be detected, a gate position discriminating means for processing an output signal of the sand mold upper surface sensor to judge the position of the sprue in the conveying direction, and a movement to an optimum conveying direction extracting position calculated from the sprue position. And a control means for instructing the casting extractor to output the sand mold upper surface sensor, wherein the sand mold upper surface sensor is integrated with the casting extractor.

Various types of sand type upper surface sensors can be employed. For example, a linear imager that captures an image in the transport direction across the gate can be used. As this linear imager, an infrared linear imager that detects infrared rays emitted from the upper surface of the sand mold can be used.

The sand mold upper surface sensor may detect a state of one point of the sand mold upper surface as long as the casting extracting device can be moved in the transport direction. An optical sensor, a radiation thermometer, or an infrared sensor can be used as a sensor for detecting the state of one point on the sand mold upper surface. Along with the movement of the casting removal device in the transport direction, a sensor that detects the state of one point on the upper surface of the sand mold detects the upper surface state of the sand mold in the transport direction.

As still another example of the sensor that detects the state of one point on the sand mold upper surface, a type that moves a contact in contact with the sand mold upper surface in the transport direction, magnetism, ultrasonic waves, or the like can be used.

[Operation] In this frameless casting line, the conveyor device intermittently transports the frameless sand mold row. The top of the sand mold of a frameless sand mold row consisting of a plurality of sand molds connected in a line in the traveling direction is provided with a gate regularly (generally at regular intervals), and the sand top sensor is the state of the top of the sand mold including the gate Is detected at least in the transport direction. The gate position determining means processes the detected sand mold upper surface state to separate the gate from the sand mold, and determines the position of the gate in the transport direction. Since the gate position and the casting position are set in advance in a fixed relationship, the casting position in the transport direction can be accurately estimated based on the determination of the gate position in the transport direction. Based on the information on the casting withdrawal position, the casting withdrawing arm drive means controls the moving amount of the casting withdrawing device in the transport direction to control the casting withdrawal position in the transport direction to ensure the casting regardless of fluctuations and variations in the casting withdrawal position. Extract to

In particular, in the present invention, the sand type upper surface sensor is provided in the casting extracting device. Therefore, it is not necessary to measure the relative distance between the sand mold upper surface sensor and the casting extracting device with respect to the sand mold upper surface sensor.

That is, it is not necessary to correct the gate position determined based on the signal output from the sand mold upper surface sensor by the variation in the relative distance between the sand mold upper surface sensor and the casting extractor. Since the apparatus can be moved at the same time, the occurrence of measurement errors is small.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The frameless casting line includes a conveyor device 1, a low-pass filter 6, an A / D converter 7, a casting removal device 2, a sand mold upper surface temperature measuring device (a sand mold upper surface sensor in the present invention) 3, The microcomputer 4 also serves as a gate position determining means and a control means (see FIG. 1).

The conveyor device 1 is composed of a normal belt conveyor,
1, 7, and 8 illustrate the distal end.
The conveyor apparatus 1 is operated in an interval operation, the operation time is set to 2.2 seconds, the operation suspension period is set to 12.8 seconds, and during this operation suspension period, the casting is extracted and the center position of the gate is detected. Then, the conveyor device 1 advances the frameless sand mold row 5 by a distance equal to the normal transport direction dimension Lo of one sand mold 51 during one operation time. A frameless sand molding machine and a pouring machine (not shown) are disposed on the upstream side of the conveyor device 1, and about 50 m away from the pouring device for pouring and cooling at an end portion of the conveyor device 1. A casting extracting device 2 and a sand mold upper surface temperature measuring device 3 are provided. At the end of the conveyor device 1, a sand collecting device 8 with a built-in sand collecting conveyor is provided. On the conveyor device 1, about 200 sand molds 5
A frameless sand mold row 5 formed by connecting 1 in a row is placed, and a cavity 53 for a casting product is formed at a boundary 52 between two adjacent sand molds 51, and communicates with the cavity 53. A substantially square gate 54 is provided on the upper surface of the boundary 52 (see FIG. 1). Further, in the middle of a runner 55 from the sprue 54 to the cavity 53, a plan part 56 extending in the horizontal direction perpendicular to the conveying direction is formed, and the molten metal poured from the spout 54 is cooled and solidified to form a total of four parts. A casting (product part) A made of cast iron is cast, and a casting is also formed on the gate 54, the runner 55, and the plan portion 56. Therefore, in the following description, the gate 54,
The runner 55 and the planner 56 mean a casting therein. Each sand mold
51 is about 28 cm in the normal transport direction, and one side of the gate 54 is about
Initially formed at 8 cm, and the scheme 56 constitutes the withdrawal of the casting.

The casting removal device 2 is movably supported above the end of the conveyor device 1 by a rail 20 disposed horizontally, and has a structure in which it runs on the rail 20 (seventh embodiment).
(See FIG. 8). The rail 20 has its leading end extending in the transport direction above the central portion in the left-right direction of the conveyor device 1, and the central portion of the rail 20 curves upward in the drawing in a horizontal plane,
The end of 20 is substantially perpendicular to the transport direction and is close to a hanger conveyor (not shown). A pair of extraction arms 22 and 23 project downward from the lower surface of the casting extraction device 2, and the two arms 22 and 23 face each other in the extending direction of the rail 20. The relative distance is variable by a hydraulic cylinder (not shown) built in the extraction device 2. The two arms 22 and 23 are alternately arranged two by two, and a protrusion for mounting the plan portion 56 is formed at the tip of each arm (see FIG. 6). The current position of the casting removal device 2 is constantly detected using an encoder (not shown) and is input to the microcomputer device 3.
The casting device is delivered in a constant posture by the drawing device 2 and the drawn casting is passed to a robot (not shown), and the robot hangs the received casting on a hanger conveyor (not shown). Then, the casting unloading device 2 that has passed the casting to the robot automatically returns to its reference position, and thereafter, is controlled by the microcomputer device 4 every time the conveyor is stopped, and moves at a constant speed in the transport direction to detect the gate position. I do.

The sand mold upper surface temperature measuring device 3 has a radiation thermometer section fixed to the lower end surface of the casting extracting device 2. The radiation thermometer section is disposed downward above the central portion in the left-right direction of the conveyor device 1, and emits infrared rays emitted from each part of the upper surface of the sand mold of the frameless sand mold row 51 as the casting extracting device 2 moves in the transport direction. Detect sequentially in the transport direction. And the sand mold just below
The upper surface temperature of 51 is output to the microcomputer device 4.

Therefore, during the operation suspension period of the conveyor device 1, the casting unloading device 2 moves by L in the transport direction, and as a result, the sand mold upper surface temperature measuring device 3 images the sand mold upper surface of the frameless sand mold row 51 by a distance in the transport direction each time. I do. The one-time imaging distance L is set to be larger than the dimension Lo in the transport direction of the sand mold 51, and at least one gate 54 can be completely imaged by one imaging operation. Since the temperature of the upper surface of the sand mold 51 is 200 ° C. or less according to actual measurement, and the temperature of the gate 54 is about 500 ° C., the sensitive wavelength band of the radiation thermometer section using an infrared filter is 3 μm to 0.8 μm. And 2 μm to 1 μm
m. In such a wavelength band, infrared energy generated from sand is insignificant,
It is advantageous to separate sand and gate.

 The results of the actual measurement of the temperature of the upper surface of the sand mold are shown below.

Center position of the gate: 391 ° C to 567 ° C, average 494 ° C Sand surface near the gate: 78 ° C to 173 ° C, average 130 ° C Sand surface between the gates: 77 ° C to 149 ° C, average 114 ° C Is caused by the time elapsed since the start of the line, fluctuations in temperature, fluctuations in various line speeds, and the like.

The low-pass filter 6 cuts off the high-frequency component of the output signal voltage (sand-type upper surface temperature signal) V from the sand-type upper surface temperature measuring device 3 and sends only the low-frequency component VL to the A / D converter 7. The A / D converter 7 A / D converts the low frequency component VL,
The digital sand mold upper surface temperature signal Vdd is input to the microcomputer device 4.

The microcomputer device 4 calculates the center position m of the gate by calculating the digital sand mold upper surface temperature signal Vdd, obtains the position (drawing position) of the casting part 56 from the obtained center position m of the gate, and sets the casting extracting device 2 It has a function of moving in the transport direction and moving above the pull-out position. Then, the microcomputer device 4 lowers the casting withdrawing device 2 to pierce the pair of extraction arms 22 and 23 on both sides in the transport direction of the plan portion 56 (see FIG. 2), and then bring the extraction arms 22 and 23 close to each other. (See FIG. 3), and the plan part 56 is gripped. Next, after the casting unloading device 2 is pulled up (see FIG. 4), it is moved along the rail 20, and is hooked on a hanger of a hanger conveyor (not shown) by a robot (not shown).

Hereinafter, the detailed operation of the microcomputer device 4 will be described with reference to FIGS.
This will be described with reference to the signal waveform diagram shown in the figure and the flowchart shown in FIG.

First, initialization is performed in S10, and the process waits until the conveyor start signal S1 is input (S12). The conveyor start signal S1 and the conveyor stop signal S2 are input to the microcomputer device 4 from a central control device (not shown) for controlling the conveyor device 1.
When the conveyor start signal S1 is input, after 2 seconds elapse (S14), before the elapse of 10 seconds (S16), if the conveyor stop signal S2 is input, the process proceeds to S20, and in a state where the conveyor stop signal S2 is not input, 10 After a lapse of seconds (S16), it is determined that the conveyor start signal S1 input in S12 is not a normal signal and S12
Return to

With the execution of S12 to S16, an abnormal conveyor start signal S1 other than during normal interval operation causes the casting unloading device 2
Can be prevented from operating.

When the conveyor stop signal S2 is input (S18), the casting unloading device 2 is moved from the predetermined standby position to the upstream side in the transport direction by a distance L.
(= 1.5Lo) at a constant speed (S19), while the sand mold upper surface temperature measuring device 3 sends the comparator 6 and the A / D converter 7
And at the same time, a signal Vz indicating the position of the casting unloading device 2 in the transport direction is received from the encoder (not shown) that outputs the current position of the casting unloading device 2 in the transport direction. (S20).

Next, the received digital sand mold upper surface temperature signal Vdd and the casting extractor position signal Vz are processed to calculate the intermediate position in the transport direction of the gate 54, that is, the gate center position m, and the transport direction coordinate position L1, of the gate center position m, Find L2 (see Figure 10). However, the transport direction coordinate positions L1 and L2 indicate distances from the sensor reference position. The gate center position calculation subroutine is executed as follows. That is, the input digital sand mold upper surface temperature signal Vdd is binarized by a preset threshold voltage Vt to obtain a binarized signal Vd, which is a high temperature region Sm corresponding to the level 1 region of the binarized signal Vd. An intermediate point between the rising edge and the falling edge is determined as the gate center position m. In this embodiment, the threshold voltage Vt corresponds to the threshold temperature Tt (300 ° C.). In FIG. 1, two gate positions m are detected by one imaging, but in some cases, one gate position m is detected by one imaging. However, 2 times with one imaging
When detecting the individual gate center position m, the gate center position on the downstream side in the transport direction is the gate center position m to be detected this time.
And Then, one end of the high temperature region Sm (see FIG. 10)
In the case where the center position m of the high temperature area Sm cannot be detected accurately when it is at either end of the imaging area, the other high temperature area (upstream area) Sm (on the upstream side in the transport direction) Sm cannot be detected accurately. Find the center position m.

Next, the casting removal device 2 is moved in the transport direction so that the center point of the casting removal device 2 is located above the determined gate center position m (S24). When the casting removal device 2 reaches the target position (S26), the casting removal device 2 The casting is extracted as described above (S2
8).

In the above-described embodiment, the sand mold upper surface sensor is of a type that measures the temperature of one point of the sand mold upper surface in a non-contact manner. For example, an infrared linear image sensor is used to stop the operation of the conveyor device 1 during the non-operation period. It is also possible to stop the casting extracting device 2 at the reference position inside, and then to image all at once at a distance L in the transport direction from the infrared linear image sensor.

Further, a magnetic sensor or an ultrasonic sensor can be used.

[Effect of the Invention] As described above, the frameless casting line of the present invention
A sand mold upper surface sensor is provided on the lower surface of the casting extractor to detect the position of each sprue, determine the position of the casting to be extracted from the detected sprue position, align the extractor, and then extract, so that the following effects are obtained. be able to.

(1) The position at which the casting is extracted can be accurately estimated.
As a result, it is possible to reliably extract the casting regardless of fluctuations and variations in the position of the casting in the transport direction. In addition, since the position of the extracted casting is always constant, and the extracted portion of the casting can be gripped or placed at a fixed portion of the extraction arm, the subsequent handling of the casting is simplified and its automation is easy. Becomes

Further, in the present invention, since the casting withdrawal position is determined from the gate position integrated with the casting, the invisible casting withdrawal position can be reliably determined.

(2) According to the present invention, the casting removal device is accurately guided and guided to the casting removal portion, so that the mold portion integrally formed with the gate can be gripped, and the product portion of the casting as in the prior art can be grasped. Does not need to be gripped in the vertical direction and does not hurt.

In addition, it is not necessary to consider the above gripping when changing the shape of the product part of the casting.

(3) Even if the gate is covered with sand and the shape of the gate becomes abnormal, a small amount of sand on the casting of the hot gate is heated by the casting of the gate and becomes higher in temperature than other parts of the sand. In addition, erroneous detection of the gate shape is reduced as compared with optical detection. In addition, although the shape of the gate becomes abnormal due to the dripping at the gate,
A small amount of the dripping portion hanging on the sand around the gate is cooled by the low-temperature sand and becomes lower in temperature than the casting of the gate, so that false detection of the gate shape is reduced as compared with optical detection.

(4) In particular, according to the present invention, since the sand mold upper surface sensor is disposed in the casting extracting device, the relative position between the sand mold upper surface sensor and the casting extracting device despite the fact that the casting extracting device frequently moves in the transport direction. There is no change in distance, and there is no need to measure the relative distance between the sand mold upper surface sensor and the casting removal device. That is, it is not necessary to correct the gate position determined based on the signal output from the sand mold upper surface sensor by the variation in the relative distance between the sand mold upper surface sensor and the casting removal device.

In addition, since the casting extraction device can be simultaneously moved while detecting the upper surface of the sand mold, the occurrence of measurement errors can be minimized.

That is, according to the present invention, as compared to a frameless casting line configured to fix the sand mold upper surface sensor and move only the casting extractor in the transport direction, the moving casting extractor and the stationary sand mold upper sensor (particularly, The distance from the position (the extraction position) is always constant, and there is no need to consider the means for calculating this distance, the time, and the error.

[Brief description of the drawings]

FIG. 1 to FIG. 4 are block diagrams sequentially showing a casting withdrawing operation in one embodiment of the frameless casting line of the present invention.
The figure is a schematic perspective view showing an example of an abnormal sand mold in a frameless sand mold row, FIG. 6 is a plan view of the casting A in FIG. 1, FIG. 7 is a plan view of an end portion of the conveyor device 1, and FIG. FIG. 9 is a side view of an end portion of the apparatus 1, FIG. 9 is a top view of a sand mold upper surface temperature distribution chart of the frameless sand mold row 5 at the end section of the conveyor apparatus 1, FIG. 10 is a signal waveform diagram showing signal waveforms of each section, and FIG. 6 is a flowchart of the device 4. DESCRIPTION OF SYMBOLS 1 ... Conveyor device 2 ... Casting removal device 3 ... Sand mold upper surface temperature measuring device (Sand mold upper surface sensor) (Sand mold upper surface sensor) 4 ... Microcomputer device (Gate position discriminating means) (Extraction arm driving means)

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-215428 (JP, A) JP-A-64-83370 (JP, A) Jiko 64-7013 (JP, Y2)

Claims (1)

(57) [Claims] 1. A conveyor device for intermittently conveying a frameless sand mold row composed of a plurality of sand molds connected in a row in a traveling direction and each having a gate, and a conveyor arm having a pull-out arm for extracting a casting from the sand mold. A casting extractor disposed movably in the conveying direction above the distal end, a sand upper surface sensor disposed above the distal end of the conveyor device to detect the state of the upper surface of the sand mold, and an output of the sand upper surface sensor A gate position determining unit that processes a signal to determine the position of the gate in the transport direction; and a control unit that instructs the casting extracting device to move to the optimal transport direction extraction position calculated from the gate position. The frameless casting line, wherein the sand mold upper surface sensor is disposed integrally with the casting extracting device.