JPH02165842A - Method for inspecting deformation of sand mold - Google Patents

Abstract

PURPOSE:To execute an inspection without any fear of collapsing a cavity having complicated shape by measuring the prescribed position of mating face formed in a sand mold, obtaining the actual height of the mating face and judging the deformation degree of the sand mold from the height difference between the setting reference mating face and the actual one. CONSTITUTION:A micro computer 23 is initially set and by fetching distance signals from optical type distance sensors 1a-1c, height of front end upper face 41 of a flask 4, height of the mating face 31 in the sand mold 3 and height of rear end upper face 42 of the flask 4 are measured in order. The reference mating face height at each linear part in the mating face is calculated from each measured height, and the difference between thin and the actual mating face height is calculated over the whole lines at each linear part. In the case the calculated absolute value is less than the permissible value, the sand mold 3 is decided to good. In the case this is more than the permissible value, malsignal is outputted to a display device 24.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a sand mold deformation inspection method for inspecting deformation of a sand mold due to transportation or the like.

[Prior art] In a conventional mold casting line, a pair of upper and lower sand molds formed by a sand molding machine are conveyed by a conveyor, and they are overlapped in front of a pouring machine to form a dense part inside. A mold with a cavity is formed and then the metal is poured into the mold.

In this conventional mold casting line, large and heavy casting boxes are conveyed by a series of intermittent conveyor operations, so the shape of the cavity in the sand mold is distorted before pouring due to the mechanical impact force when the conveyor starts and stops. There was a problem that it deformed.

Conventionally, to inspect this cavity deformation, the mold making line was temporarily stopped and measurements were taken using a ruler, dial gauge, etc. to avoid destroying the cavity shape.

[Problems to be Solved by the Invention] However, in the conventional inspection method described above, it takes a long time to inspect each part of the cavity, and during that time it is necessary to stop the mold casting line.

In addition, since the sand mold that is the object of measurement is fragile, there is a drawback that the measurement results vary from person to person.

The present invention has been made in view of these problems, and it is an object of the present invention to provide a sand mold deformation inspection method that can be inspected in a short time and does not cause the risk of damaging the cavity.

[Means for Solving the Problems] The sand mold deformation inspection method of the present invention is a method for inspecting deformation of the cavity shape of a sand mold formed in a casting box, which includes measuring a predetermined portion of a fit formed in the sand mold. a step of measuring the actual height of the mating surface by determining the actual height of the mating surface;
a reference mating surface measurement step of determining the height of the reference mating surface in the absence of sand mold deformation by measuring a plurality of reference points set on the casting box; It is characterized by comprising a sand mold deformation determination step of determining the degree of sand mold deformation from the difference.

The reference point of the casting box is preferably set on the upper surface of the end of the casting box, and particularly preferably on the upper surface of both ends of the casting box.

The height of the mating surface of the sand mold and the reference point of the casting box can be measured not only vertically, but also diagonally or horizontally. Non-contact distance sensors such as an optical type or an ultrasonic type can be used as distance measuring means for measuring the altitude.

[Example] A sand mold deformation testing device used in an embodiment of the sand mold deformation testing method of the present invention will be described with reference to FIGS. 1 and 2.

This sand mold inspection device is a 3111 optical distance sensor 1a.
11b11C and this optical distance sensor la.

The sand mold 3 on the conveyor (not shown) is judged to be good or bad by processing the signals outputted from the sand molds 1b and 1c. This sand mold inspection device is disposed facing downward above the conveyor at a position closer to the pouring machine between the sand mold making machine and the pouring machine of a sand mold casting line (not shown).

As shown in FIGS. 1 and 2, the sand mold 3, which is the object to be inspected, is filled in a steel casting box 4 having a rectangular box shape with an open top, and molten metal is poured into the top surface of the sand mold 3. A total of six cylindrical cavities 32 into which hot water is poured are formed. Here, the long side of the casting box 4 is about 0.85 m, the short side is about 0.56 m x ^, and the length is about 16 cm. The weight of U box 4 with sand mold 3 is approximately 1
57 to 9, and the conveyor is loaded with dozens of &8 boxes 4 and is operated at intervals.

The cavities 32 are arranged in two rows of three cavities parallel to the long side direction of the casting box 4, that is, the traveling direction X of the conveyor. , the mating surface 31 of the sand mold 3 is formed to be the same surface as the front end upper surface 41 and the rear end upper surface 42 of the casting box 4,
In an ideal state where there is no misalignment on the conveyor, it extends horizontally.

The optical distance sensors 1a and 1b11c are arranged in a line at equal intervals in a direction perpendicular to the traveling direction X of the conveyor, and as shown in FIG. Above, the optical distance sensor 1a is arranged above the right r1 part, and the optical distance sensor 1C is arranged above the left end part. Each capacitance 32 is designed to pass just between the optical distance sensor 1b and the optical distance sensor 1a and between the optical distance sensor 1b and the optical distance sensor 1C.

The distance d between the lower end of each optical distance sensor 1a11b, 1c and the mating surface 31 of the sand mold 3 is set to approximately 4 cm. Optical distance sensor 1a.

1b and 1c are light emitting diodes (not shown) and PSD (
(not shown) and measures the distance to the target image by triangulation, but since it is well known, a detailed explanation will be omitted.

The discrimination device 2 includes optical distance sensors 1a and 1b.

Each sense amplifier 21 amplifies the distance signal output from 1C, each low-pass filter 22 band-limits the distance signal amplified by each sense amplifier 21, and each low-pass filter 22 processes the band-limited distance signal. A microcomputer 23 with a built-in △/D converter that determines the degree of sand mold deformation.
and a display device 24 for displaying pass/fail.

Next, the measurement operation of this sand mold deformation testing method will be explained with reference to the flow chart shown in FIG. It is assumed that the casting box 4 is moving below the optical distance sensors 1a, ib, and 1C at a speed of about 0.1 m/sec.

First, after initializing the microcomputer 23 (S101), distance signals are taken in from the optical distance sensors 1a, 1b, and 1C, and from the taken in distance signals, the height of the front end upper surface 41 of the key box 4 and the mating surface of the sand mold 3 are determined. 31 and the height of the rear end upper surface 42 of the &4 box 4 are sequentially measured.

More specifically, as shown in FIG.
Height of reference point d on rear end upper surface 42 of key box 4, reference point a-d
Measure the height of the linear portion Ω of the mating surfaces between the two.

The optical distance sensor 1b has a height of a reference point e on the front end upper surface 41 of the key box 4, a height of a reference point e on the rear end upper surface 42 of the key box 4,
Measure the height of the linear portion of the mating surface between reference points b and e. The optical distance sensor 1C is located on the front end upper surface 41 of the key box 4.
, the height of the reference point f on the upper surface 42 of the rear end of the key box 4, and the height of the linear portion i of the mating surface between the reference points c and f.

Next, the reference mating surface angles of the linear portions g, h, and i of the mating surfaces are calculated from the measured heights of the reference points a to f. The reference mating surface angle of each of these linear portions 9 and hl 1 is the key box 4
This is the ideal height of the mating surface 31 initially formed so as to be in line with the front end upper surface 41 and the rear end upper surface 42 of the reference point a-dSb-e, as shown in FIGS. 4 to 6. ,c
Straight lines S1, S2, S on each linear part 9, h, i connecting -f
It is represented by 3.

Next, the calculated reference mating surface angle 8 of each linear portion 9, h, i
1. Difference Δml-8 between S2, S3 and the actually measured actual alignment surface angles A1, A2, A3 (see Figure 2)
1-AI, 6m2-82-A2.6m3-83-A3, each linear part G, h.

The calculation is performed over the entire line of i (S107).

Then, it is checked whether the absolute value of the calculated Δm1.6m2.6m3 is less than a predetermined tolerance value (8109),
If it is less than that, the measured sand mold 3 is deemed to be a good product and the routine is terminated to prepare for the arrival of the next sand mold 3. Further, if the value is larger than the allowable value, a defect signal is output to the display device 24, and an instruction to stop the next pouring of metal is given to the pourer (not shown).

The sand mold inspection method of this embodiment described above has the following advantages.

(1) The present inventor discovered that the deformation of the cavity 32 of the sand mold 3 due to the start and stop of the conveyor has a correlation with the deformation of the mating surface 31 and the top surface of the sand mold in the height direction. Therefore,
By inspecting the deformation of the mating surface 31 in the height direction, the degree of deformation of the cavity shape can be estimated easily and quickly.

(2) In this embodiment, it is possible to check whether the mating surface 31 of the sand mold 3 itself is Q or not. In addition, if the mating material 31 is deformed, a gap may be formed between the pair of sand molds that are superimposed.
Part of the sand mold may break.

(3) In this embodiment, the height of the mating surface 31 of the upper surface of the sand mold 3 is measured, so even if the height of the cavity 32 is
Even if the shape of the microcomputer 23 is changed, changes in the data input to the microcomputer 23 can be minimized.

(4) A signal to stop pouring into the sand mold 3 that has been determined to be defective is output to the pouring machine (not shown), reducing waste of molten metal and eliminating the trouble of sorting and processing defective products. Can be done.

(5) Since the mating surface 31 of the sand mold 3 has a planar shape, the optical distance sensors 1a, 1b, 1 are attached to the moving mating surface 31.
c can be made close to each other, and measurement accuracy can be improved.

(6) Since the reference mating surface angle of the mating surface 31 is calculated from the altitude of a plurality of reference points a to f provided on the upper surface of both ends of the key box 4, it is possible to prevent changes in the posture of the key box 4 that occur during transportation. Regardless, the reference mating surface angle of the mating surface 31 can be calculated easily and reliably.

[J'l! As explained above, the sand mold deformation inspection method of the present invention determines the degree of deformation of the cavity formed in the sand mold from the degree of deformation in the height direction of the mating surface of the sand mold. Even if it is complex, it can be inspected at high speed, and there is no risk of damaging the cavity due to this inspection.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a sand mold inspection device that implements the sand mold deformation testing method of the present invention, FIG. 2 is a plan view of the key box 4, FIG. 3 is a flowchart showing the operation of the sand mold inspection device, and FIG. 5 and 6 are position diagrams showing the reference mating surface height and the actual mating surface height of the mating surface 31, respectively. Patent applicant Aisin Takaoka Co., Ltd.

Claims (1)

[Claims] (1) A method for inspecting cavity deformation of a sand mold formed in a casting box, including a step of measuring an actual mating surface height by measuring a predetermined portion of the mating surface formed in the sand mold to obtain an actual mating surface height; a reference mating surface measurement step of determining the height of the reference mating surface in the absence of sand mold deformation by measuring a plurality of reference points set on the casting box; and a difference between the actual mating surface height and the reference mating surface height. A sand mold deformation inspection method comprising a sand mold deformation determination step of determining the degree of sand mold deformation based on the sand mold deformation.