JPH05212492A - Method for measuring deviation - Google Patents

Abstract

PURPOSE:To accurately measure deviation quantity and to obtain a casting having good dimensional accuracy by putting a steel ball at the upper surface side of the pattern, molding, pouring molten metal after joining molds and measuring the distance between steel balls and a reference line after obtaining a casting with the steel balls protruded on the upper and the lower surfaces. CONSTITUTION:At the time of molding a pattern for cope and a pattern for drift, the steel balls are put on the upper surface and molded and the steel are held in a molding sand and allowed to remain in a cavity. Mold joining is executed and the molten metal is poured to cast the casting. The steel balls 7 is inserted at the projecting part 2b on the upper surface 2a in the upper part 2 and at the projecting part 3b in the lower part 3 of the casting 1. Distances from the reference line X, Y, Z to the center of the steel balls 7 are measured. The steel balls 7 after measuring is removed with the grinder, etc. As the distances are measured from the steel balls on the flat surfaces, the deviation quantity can accurately be measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the difference in casting castings.

[0002]

2. Description of the Related Art In general, a casting is manufactured by aligning an upper mold and a lower mold, which are separately molded, and pouring a molten metal into a cavity formed by the upper and lower molds. Therefore, if there is a misalignment between the upper die and the lower die, the resulting die mating surface (partition surface)
There will be a discrepancy. If the difference in size is large, not only in appearance but also in dimensional accuracy and the like, the product becomes defective and the manufacturing yield is lowered, resulting in high cost.

For this reason, conventionally, when molding a lower mold, embedded fitting pins are provided on both sides in the longitudinal direction of a lower mold model surface plate on which a lower mold model and the like are arranged, and a casting for the lower mold is performed. The fitting bushes are embedded on both sides in the longitudinal direction of the frame, and when the casting frame is placed on the model surface plate during molding, the fitting pins of the model surface plate are fitted with the fitting bushing of the casting frame for positioning. After that, we are molding.

Further, in the case of molding the upper mold, fitting bushes are embedded on both sides in the longitudinal direction of an upper mold model surface plate on which an upper model and the like are arranged, and at the same time, fitted on both left and right sides in the longitudinal direction of the casting frame. When the molding pin is embedded and protruded and the molding frame is placed on the model surface plate during molding, the fitting pin of the molding frame is inserted into the hole of the fitting bush of the model surface plate for positioning, and then the molding is performed. Is going.

In order to match the lower mold and the upper mold, which have been molded as described above, the lower mold after molding is turned upside down and held in the hole of the fitting bush of the casting frame. The fitting pin of the casting frame is fitted and positioned, and the lower mold is covered with the upper mold to form a cavity inside.

[0006] As described above, during molding, positioning of the lower and upper mold flasks and the lower and upper model surface plates,
In addition, the positioning of the lower mold and the upper mold at the time of mold matching has conventionally been performed by a fitting pin and a fitting bush.

According to the above-mentioned conventional positioning method using the fitting pin and the fitting bush, the outer diameter surface of the fitting pin and the inner diameter surface of the fitting bush wear due to repeated positioning for molding or die matching. The amount of looseness in mating is gradually increasing, which is a cause of misalignment. In the worst case, in particular, when the lower mold is formed, the upper mold is formed, and the misalignment due to the fitting backlash is accumulated at each time of the mold alignment, a large mold deviation may occur, which may cause a large discrepancy. there were.

The cause of the discrepancy is not only the fitting backlash due to the wear of the fitting pin and the fitting bush, but also the springback of the mold surface due to the unevenness of the mold tightness at the time of molding, the poor flatness of the mold, and the mold tension. Is mentioned. When a discrepancy occurs, it affects not only the appearance but also the dimensional accuracy as described above. When the discrepancy amount becomes 0.5 to 1 mm, it becomes a problem, and when it exceeds 1 mm, it becomes a defective product and the manufacturing yield increases. In some cases, it causes the cost to rise.

For this reason, conventionally, measures have been taken to prevent the occurrence of misalignment, mainly by measuring the degree of wear of the mating pin and mating bush, but there are other causes of misalignment. Finally, we measure the amount of discrepancy by actually extracting the cast product and taking countermeasures based on that data.

[0010]

In order to obtain the amount of discrepancy by measurement, for example, as shown in FIG. 3, the total length A of the casting 1 and the length of the portion 2 above the parting line PL (the lower portion 3 may be used). B
It is possible to obtain the difference in amount C = A−B by measuring However, since the above-mentioned measurement is performed on the uneven black skin surface, a measurement error of about 0.2 to 0.3 mm occurs. Further, when measuring the total length A and the length B, the measurement point is not sharp due to mold breakage, so that an error of about 0.3 mm to 0.5 mm is likely to occur in the measurement accuracy. The present invention provides a stagger measurement method that can accurately measure the stagger amount and can contribute to a stagger prevention measure, and that is useful for manufacturing a high quality casting with good dimensional accuracy at low cost. The purpose is that.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and its construction is such that a steel ball can be removed on the upper surface side of an upper model and a lower model during molding. Place and mold the upper mold and the lower mold respectively, leave the steel ball in the mold and perform die cutting, pouring after mold matching, casting the steel ball in a casting, projecting from the upper and lower surfaces of the casting After cleaning the casting, measure the distance from the reference line to the center of the steel ball protruding from the upper and lower surfaces of the casting with a measuring instrument,
The feature is that the amount of stagger is calculated by comparing the measured values.

In the cast product, steel balls having a smooth surface are cast on the upper surface side above the parting line and on the lower surface side below the parting line. The distance to the center can be measured very accurately. Therefore, the amount of stagger calculated based on this measured value is also extremely accurate,
It is very important to contribute to the countermeasure against the discrepancy.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a front sectional view of an upper mold (or a lower mold) after molding, and FIG. 2 is a front view showing a measurement situation. In FIG. 1, the upper model 5 arranged on the model surface plate 4 is provided with a predetermined position (center in this embodiment) on the surface 5a which is to be raised during molding.
The surface of the steel ball 7 is polished and smoothed through the cylindrical holding piece 6.
Is placed so that it can be removed, and in this state, the casting frame 8 positioned on the model surface plate 4 via a pin / bush device (not shown) is placed, and the casting sand 9 is placed in the casting frame 8. Supplied,
It is molded by a molding machine (not shown).

In this embodiment, however, the holding piece 6 on which the steel ball 7 is placed has a cylindrical shape as shown in FIG. 1, and the inner diameter is smaller than the outer diameter of the steel ball 7. Therefore, when the steel ball 7 is placed on the holding piece 6, the steel ball 7 is placed stably with the center of the holding piece 6 aligned with the center thereof. Further, since the molding sand 9 is packed between the spherical surface of the steel ball 7 directed downward and the upper surface of the holding piece 6 by the molding, even if the holding piece 6 is die-cut with the model 5, the steel ball 7 Is held by the casting sand 9 and remains in the cavity of the upper mold 2 and does not fall even in the downward state.

Instead of the cylindrical body, the holding piece 6 may be, for example, a columnar piece having a conical concave portion or other projecting piece. Further, it is not necessary to cast the steel balls 7 for the measurement of the stagger in all the castings. For example, when performing the casting every predetermined number of moldings, the holding piece 6 is detachably attached to the upper surface 5a of the upper die model 5, You may make it possible to attach only when necessary.

Although the above describes the case where the upper mold 10 is molded, the steel balls 7 can be left in the cavity of the lower mold 11 after die cutting in the same manner as in the molding of the lower mold 11. After molding the upper mold 10 and the lower mold 11, the molds are matched with each other through a pin / bush device (not shown) provided on the flange portion of the casting frame 8 in the same manner as in the conventional case, and then pouring is performed to cast a casting. I do.

After the solidification of the poured molten metal is waited for, the mold is released, post-processing such as folding of the sprue and cleaning with sand is performed to obtain a casting 1. As shown in FIG. 2, the casting 1 is composed of a portion 2 above the parting line PL formed by the upper model 5 and a part 3 below the parting line PL formed by the lower model. Then, on the upper surface 2a of the upper portion 2, a projecting portion 2b is formed in a portion formed by the holding piece 6 of the upper die model 5, and a steel ball 7 is cast on the upper end surface thereof. Further, in the lower portion 3 as well, a steel ball 7 is similarly cast on the lower end surface of the protruding portion 3b.

In measuring the amount of stagger C, the casting 1 is arranged as shown in FIG. 2 and, for example, from the reference lines X, Y and Z (not shown in the figure) to the center of the steel ball 7 by a three-dimensional measuring instrument. Measure the distance of each. FIG. 2 shows the measurement state of the discrepancy amount C in the X-axis direction, which is calculated by the discrepancy amount C = X ₁ -X ₂ in the X-axis direction. Since the surface of the steel ball 7 is smooth, it is extremely accurate (error 0.02 to 0.05 m).
It can be calculated.

In the same manner, the amount of misalignment in the Y-axis and Z-axis directions can be accurately measured, the cause of the misalignment can be clarified, and countermeasures for misalignment can be taken. Then, this measurement may be performed by casting a test piece in which the steel ball 7 is cast, or may be performed for each predetermined number of moldings in the casting line as described above. Further, by casting a plurality of steel balls 7 on each surface, it is possible to more accurately know the staggering condition such as the staggering amount. In addition, the steel ball 7 after the measurement is completed
Can be removed by polishing or the like together with the protrusions 2b and 3b to form a casting as a product.

[0020]

As described above, according to the present invention, since the distance is measured by the steel balls having the smooth surface, the amount of misalignment can be calculated extremely accurately, and by accurately taking measures against the misalignment, high accuracy and high accuracy can be achieved. The great effect is that quality castings can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is an upper mold (or a lower mold) according to an embodiment of the present invention.
It is sectional drawing after modeling.

FIG. 2 is a diagram showing an example of a measuring state of the amount of stagger.

FIG. 3 is a diagram showing a conventional method for measuring a stagger amount.

[Explanation of symbols]

 1 casting 2a casting upper surface 3a casting lower surface 4 model surface plate 5 upper model 5a upper surface of upper model 6 holding piece 7 steel ball 10 upper mold 11 lower mold

Claims (1)

[Claims] 1. A steel ball is removably placed on the upper surface side of an upper mold and a lower mold during molding to mold the upper mold and the lower mold, respectively, and the steel ball is left in the mold for die cutting. After casting, mold casting and pouring the steel balls into a casting to cause them to project from the upper and lower surfaces of the casting, and after cleaning the casting, steel that projects from the reference line by the measuring instrument from the upper and lower surfaces of the casting. A stagger measurement method, which comprises calculating a stagger amount by measuring a distance to a center of a sphere and comparing the measured values.