JP3174846U - Insertable neck down core - Google Patents

Abstract

To provide a simple and effective insertion type neck down core for tightly inserting and fitting a feeder into a cavity portion.
The tightness of insertion fitting is increased by providing irregularities or protrusions on the outer diameter portion of the neck down core, or by making the thickness of the outer diameter portion larger than the thickness of the neck forming opening.
[Selection] Figure 1

Description

Detailed description of the invention

Industrial application fields

  The present invention relates to an improvement in a neck down core that is used by being inserted into a cavity portion of a feeder after casting in casting. The object is to provide a neck-down core that has a simple shape and tightly fits the insertion of the feeder into the cavity portion.

  In casting, in order to improve the soundness of the product part, a hot water is provided at an appropriate part of the product part, and the solidification shrinkage of the product part is replenished from the hot water. Liberation hot water is used. These hot water feeders are classified into fried hot water and side hot water depending on the position where the product part is attached. The fried hot water is attached to the top of the product part, and the side hot water is attached to the side of the product part. In general, the hot water feeder is more effective than the side hot water because it can be installed directly or in the vicinity where defects in the product portion are likely to occur. As a result, the casting yield is high because the feeder is reduced. The present invention relates to a neck down core used for a fried hot water.

  In some cases, the raised hot water is provided without a neck-down core at the top of the product. In this case, the hot water separation after casting becomes saw cutting or gas cutting. In order to facilitate the separation of the hot water after casting, a neck down core is used at the bottom of the raised hot water. The weir portion when the neck down core is used is referred to as a neck formation opening portion. Usually, the neck down core is used by being inserted into the bottom portion of the cavity portion of the feeder after mold forming, and this is called an insertion type neck down core.

  A prior art case 1 is shown in FIG. In case 1, the neck down core 3 is inserted into the bottom of the cavity part 2 of the hot water provided at the top of the product part 1 after molding, but the neck down core 3 is naturally set in the upper mold. Therefore, if the fitting between the outer diameter of the neck down core 3 and the inner diameter of the cavity portion 2 of the feeder is loose, the neck down core 3 may fall due to an impact during conveyance of the mold. On the other hand, if a large tightening allowance is used to make the fitting close, the neck down core 3 may not be inserted or may be forcibly inserted to break the mold. For this reason, the neck down core 3 is rarely used alone, and is often used at the bottom of a feeder sleeve (not shown) which is inserted into the cavity portion 2 of the feeder to enhance the feeder effect. It is.

  As a countermeasure, in the case 2 of the prior art, the outer diameter of the neck down core 3 is increased and the adhesive 8 is used as shown in FIG. In case 3, it is stopped with a nail 9 or the like as shown in FIG. Since both are time-consuming operations, the neck down core is only used for some non-mass production castings, and is rarely used in high-speed automatic molding lines for mass production.

JP-A-11-104811 JP-A-5-337600

Problems that the device tries to solve

  As described above, the neck down core is used for the weir part at the bottom of the raised feeder, and has a large feeder effect, and is useful for facilitating the separation work of the feeder after casting by the narrow neck formation hole. It is a member. However, when inserting the feeder into the cavity part, the neck down core alone is used because it does not have a sufficient degree of adhesion and a tight fit cannot be obtained, or laborious work such as adhesive and nailing is required. There is little to be done. In particular, it is rarely used in high-speed automatic molding lines. These are major problems in terms of energy saving and productivity improvement in the casting process.

  The present invention provides a simple and effective technique for tightly inserting and fitting the neck down core into the cavity of the feeder. Accordingly, the insertion type neck-down core is widely used, and is particularly intended to be applied to a high-speed automatic molding line.

Means for solving the problem

(Means 1)
A neck-down core that is inserted into the bottom of the cavity part of the feeder after casting and is used for casting. It is an insertion type neck down core characterized by providing irregularities or projections.

(Means 2)
A neck down core that is inserted into the bottom of the cavity part of the feeder after casting and is used in casting. An insertion-type neck down core characterized in that the thickness is made larger than the thickness of the neck forming opening.
The means 1 and means 2 will be described in detail below.

Action

  First, the means 1 will be described. The disadvantages of the insert type neck down core in the prior art are as follows. In actual molding or molding, fluctuations in the inner diameter after molding due to fluctuations in the sand properties of the cavity of the feeder, mold breakage, etc., and on the other hand, the outer diameter due to fluctuations in the molding conditions of the neck down core Variations due to variations or thinness occur. These are the causes of looseness of fitting when the neck down core is inserted. These problems cannot be solved even if an appropriate tightening allowance is provided when inserting into the inner diameter of the cavity portion of the feeder. In addition, since the thickness of the neck down core cannot be increased too much in order to make the hot water effective, one of the causes is that the length of the fitting portion cannot be increased.

  In order to solve the above-described problems of the prior art, the means 1 is provided with appropriate irregularities or projections on the outer diameter portion of the neck down core. In the case of unevenness, the outer diameter formed by the convex portion is made slightly larger than the inner diameter of the cavity portion of the feeder and the concave portion is made smaller than the inner diameter of the cavity portion of the feeder. As a result, the convex portion bites into the inner diameter of the cavity portion of the feeder, and the sand in that portion moves to the concave portion, so that it can be smoothly inserted without breaking the inner diameter portion of the cavity portion of the feeder, and the convex portion The neck down core can be tightly fitted by biting. In the case of only the convex, similarly, the outer diameter formed by the convex portion is slightly larger than the inner diameter of the cavity portion of the feeder, and the bottom diameter of the convex portion is slightly smaller than the inner diameter of the cavity portion of the feeder. Thus, the same effects as those in the case of unevenness can be obtained.

  The effect is the same as long as the unevenness or the convex shape is easy to bite into the inner diameter of the cavity of the feeder such as a saw blade, hemisphere, or gear. Further, it is not necessary to provide unevenness or protrusions over the entire circumference of the outer diameter portion of the neck down core, and it is not necessary to provide it over the entire thickness of the outer diameter portion. What is necessary is just to provide in the number, a position, or the range of the grade which can closely_tightly fit.

  Next, the means 2 will be described. One of the causes of the instability of fitting between the neck down core and the cavity portion of the feeder is the fluctuation of the inner diameter due to the variation of the mold sand and the fluctuation of the outer diameter of the neck down core as described above. Another cause is that the length of the fitting portion is short. Therefore, in this means, the thickness of the outer diameter part of the neck down core is made larger than the thickness of the neck forming hole. As a result, the fitting portion can be lengthened, and instability due to variations in dimensions of the cavity portion of the feeder and the neck down core can be absorbed and a close fitting can be ensured. Hereinafter, each means will be described in detail in Examples.

  First, an embodiment using the means 1 is shown in FIGS. In FIG. 1, a cavity part 2 of the feeder is formed on the upper part of the product part 1, and the neck down core 3 of the present invention is inserted and fitted into a fitting part 4 having an inner diameter of the cavity part 2 of the feeder. Indicates the state. FIG. 2 is a cross-sectional view of the neck down core 3 taken along the line AA. The saw-toothed irregularities 5 are provided in the thickness direction of the neck down core 3.

  When this neck down core 3 is inserted into the fitting portion 4 at the bottom of the cavity portion 2 of the feeder, the saw-tooth-shaped irregularities 5 are inserted so as to bite into the inner diameter portion of the cavity portion 2 of the feeder, A good fit. As a result, the neck-down core 3 inserted and fitted is not loosened and dropped even when the mold is conveyed.

  In FIG. 2, the saw-tooth-like irregularities 5 are provided over the entire circumference of the outer diameter portion and over the entire length in the thickness direction, but it is not necessary to provide the entire circumference of the outer diameter portion in practice. There is no need to provide the entire length in the direction. What is necessary is just to provide in the appropriate number, length, and range which can obtain sufficient tightness of fitting.

  Similarly, FIG. 3 shows a cross-sectional view of the same AA cross section as that of the first embodiment in FIG. 3 and FIG. 4 shows a perspective view of the second embodiment using the means 1. In this case, hemispherical projections 6 are provided at appropriate intervals on the outer diameter portion in place of the saw-toothed irregularities 5 of the first embodiment. It is not necessary to provide all the projections 6 on the hemisphere over the entire length in the thickness direction as shown in FIG. What is necessary is just to provide in appropriate length and a place. As described above, the unevenness or the protrusion provided on the outer diameter portion of the neck down core has the same effect as long as an appropriate tightness of fitting can be obtained regardless of the shape, the number, and the location.

  Next, an embodiment using the means 2 is shown in FIG. Similarly, the neck down core 3 is inserted and fitted into the bottom of the feeder cavity 2. In this embodiment, the thickness T1 of the outer diameter portion of the neck down core 3 is made larger than the thickness T2 of the neck formation opening portion 7. As a result, the length of the fitting portion 4 is longer than the thickness T2 of the neck forming hole portion in the conventional case, and the tightness of the fitting does not increase and loosen accordingly. Thus, the effect similar to Example 1 and 2 can also be acquired by enlarging the length of the fitting part 4. FIG. It should be noted that the thickness T1 of the outer diameter portion of the neck down core 3 is not necessarily provided over the entire circumference, and may be within a range where an appropriate tightness of fitting can be obtained.

  In addition, combining Example 1 or Example 2 and Example 3 is more effective with a synergistic effect. In addition, as shown in Examples 2 and 3 of the prior art, any of the embodiments can be applied to a type in which the outer diameter of the neck down core is increased.

Effect of device

As described above, according to the present invention, in the insertion type neck down core, the outer diameter portion is provided with irregularities or projections, or the thickness of the outer diameter portion of the neck down core is larger than the thickness of the neck forming aperture. By this simple and effective method, the tightness of the fitting at the time of insertion is greatly improved, and the neck down core can be used stably. As a result, the following effects were obtained.
(1) Although the insertion-type neck down core is inexpensive and has a large effect, its use has been limited in the past, but the present invention has made it possible to use it stably in a wide range of casting fields. A particularly significant effect is that it can now be applied to high-speed automatic molding lines that were rarely used in the past.
(2) The insertion-type neck down core is used for a filing hot spring that has a higher hot water effect than the side hot water, so that it can be used stably in practical terms with this device. A significant improvement was obtained. In addition, the small neck opening part of the neck down core has made it possible to facilitate the separation of the product part and the feeder part after casting.
(3) As a result of the above, energy saving in the casting process and significant improvement in productivity were obtained.

  It is a figure which shows Example 1 of this invention.   It is AA sectional drawing of Example 1 of this invention.   It is AA sectional drawing of Example 2 of this invention.   It is a perspective view of Example 2 of the present invention.   It is a figure which shows Example 3 of this invention.   It is a figure which shows the example 1 of a prior art.   It is a figure which shows the example 2 of a prior art.   It is a figure which shows the example 3 of a prior art.

DESCRIPTION OF SYMBOLS 1 Product part 2 Cavity part of feeder 3 Neck down core 4 Fitting part 5 Saw-blade-shaped unevenness 6 Hemispherical convex 7 Neck formation opening part 8 Adhesive 9 Nail

Claims (2)

  A neck-down core that is inserted into the bottom of the cavity part of the feeder after casting and is used in casting, so that the insertion fit into the cavity part of the feeder is close to the outer diameter part of the neck-down core. An insertion type neck down core characterized by providing irregularities or projections.   A neck down core that is inserted into the bottom of the cavity part of the feeder after casting and is used in casting, and the outer diameter part of the neck down core is used so that the insertion fit into the cavity part of the feeder is tight. An insertion-type neck down core characterized in that the thickness is larger than the thickness of the neck forming opening.

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