JPH08136428A - Core strength testing device - Google Patents

Abstract

PURPOSE: To evaluate molten metal shock resistance of a core without casting by arranging a specimen of sand core across a path through which one end of an arm is passed, arranging elastic members on both sides of the specimen, and arranging a pressure applying member at the back of the elastic member. CONSTITUTION: A pair of left and right supports 2 are stood on front both sides on a base plate 1, and an upper plate 3 is fixed at the upper ends of the supports 2. A shaft 5 is pivoted in the front center of the plate 3 with a bearing. An arm 6 is fixed in the center of the whole length to the front end of the shaft 5. A revolution indicator for measuring a swinging angle of the arm 6 is fixed to the rear end of the shaft 5. Rubber plates are arranged left and right sides in the lengthy direction of the specimen, a pressing plate is arranged at the back of each rubber plate, the back of the pressing plate is pressed with an interposing volt 15 to interpose and fix the specimen.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an apparatus for testing the strength of a core.

[0002]

2. Description of the Related Art In casting various products, it is necessary to use a collapsible core (for example, sand core) that can be easily removed after casting in order to obtain a specific shape of the product. Of course, in this case, the core should not be damaged during casting. In the low-pressure casting, the pressure of the molten metal is low and the pouring speed is slow, so that the core is generally not damaged. However, in medium-pressure casting or high-pressure casting typified by die casting, the pressure of the molten metal is high and the pouring speed is high, so the impact load of the molten metal injected into the casting space becomes large and damage to the sand core occurs. The risk of inviting increases. For this reason, the sand core has been rarely used for die casting, for example. However, the low-pressure casting has a problem that the pouring rate is slow and the solidification rate is slow, so that the productivity of the product is low. Therefore, it is preferable to use the die-cast casting from the viewpoint of improving the production efficiency. In this case, it is naturally necessary to confirm in advance that the sand core has sufficient strength. For that purpose, we can actually perform die casting using a sand core prototype, but such an evaluation method requires a lot of equipment, time, and cost, and it is very difficult to perform many experiments in a short delivery time. It will be difficult. Therefore, the present invention
It is an object of the present invention to provide a core strength tester capable of evaluating the molten metal impact resistance of a sand core without conducting an actual casting experiment.

[0003]

The present invention has been made to achieve the above object, that is, a weight is fixed to one end of a swingably provided arm, and a passage through which the one end of the arm passes. A sand core specimen is placed across the same, elastic members are arranged on both sides of one or both ends of the specimen, and a pressing member is arranged behind at least one of the elastic members on both sides. Is a core strength tester in which the test piece is sandwiched and fixed. At this time, the pressing member can be arranged to be movable continuously or stepwise in the direction along the longitudinal direction of the test piece.

[0004]

The present invention will be described with reference to the drawings. 1 to 4
Shows an embodiment of the present invention. A pair of left and right columns 2 and 2 are provided upright on both sides of the rear portion of the base plate 1, and an upper plate 3 is fixed to the upper ends of the columns 2 and 2. A shaft 5 is supported by a bearing 4 at the center of the front surface of the upper plate 3, and an arm 6 is provided at the front end of the shaft 5.
Is fixed at the center of its entire length. Arm 6
A ring-shaped weight 7 is detachably fixed to one end of the arm 6, that is, the number of weights 7 attached to one end of the arm 6 can be changed. On the other hand, a tachometer 9 for measuring the swing angle of the arm 6 is fixed to the rear end of the shaft 5 via a coupling 8. A pair of front and rear clamps 10, 10 are fixed on the base plate 1 so that one end of the arm 6 to which a weight 7 is attached is located in front of and behind a passage through which the block 11 is fixed. There is. Clamp 10 and block 1
1 is formed so that the upper surfaces of the intermediate portions on the sides facing each other are recessed, and thus the test piece 12 of the sand core to be tested is laid across the pair of front and rear recesses, and the weight is placed. One end of the arm 6 attached with 7 is the test piece 12
It is configured to collide with. In this embodiment, the test piece 12 has a size of 10 × 10 × 100 mm.

Rubber plates 13, 13 are arranged at both left and right sides of the test piece 12 in the longitudinal direction, and a push plate 14 is arranged behind the rubber plate 13 on the right side of the drawing. Press the back of the push plate 14 with the sandwiching bolts 15,
The test piece 12 is clamped and fixed. The lower surface of the push plate 14 is provided with one ridge 14a extending in the left-right direction,
On the other hand, the upper surface of the clamp 10 is provided with two recessed grooves 10a, 10a extending in the left-right direction, and thus, as shown by the chain double-dashed line in FIG. By engaging with the groove 10a, the test piece 1
The push plate 14 can be moved stepwise in a direction along the longitudinal direction of the second plate 2. A positioning bolt 16 is in contact with an end surface of the test piece 12 in the longitudinal direction, and the positioning position of the test piece 12 in the longitudinal direction can be changed by screwing the positioning bolt 16 into the end surface.

This embodiment is constructed as described above,
Place the test piece 12 in the recess of the front and rear clamps 10,
Rubber plates 13 are arranged on both sides of both ends of the test piece 12, and a push plate 14 is arranged behind the rubber plate 13 on the right side.
5 is screwed in to fix the test piece 12. At the same time, the front and rear positioning bolts 16, 16 are adjusted to determine the longitudinal position of the test piece 12. Then, one end of the arm 6 to which the weight 7 is attached is swung to the right in the drawing, and after the swivel angle of the arm 6 is measured by the tachometer 9, the swing of the arm 6 is released. It rotates in the direction and collides with the test piece 12. Therefore, by changing the swing-up angle of the arm 6 and the number of weights 7 attached to one end of the arm 6, the swing-up angle and the number of weights leading to the breakage of the test piece 12 are examined. The strength of the test piece 12 can be measured. Therefore, according to the present embodiment, it is not necessary to actually perform casting using a sand core prototype and check the strength of the sand core.

FIG. 5 shows an example of the test results of resin-coated sand cores having different bending strengths tested by using the above tester. As shown in FIG. 5, the bending strength of sand cores is limited. It can be seen that there is a strong correlation with the angle, that is, the swing-up angle of the arm 6 at which the test piece 12 is damaged. In this embodiment, the case where both ends of the test piece 12 in the longitudinal direction are fixed has been described.
It is also possible to measure the strength of the test piece 12 in a cantilever state by removing the plate 11 and the plate 11. Further, the concave groove 10a of the clamp with which the convex strip 14a of the push plate engages is changed to another concave groove 10a inside or outside, and the end face of the push plate 14 in that state is changed to the end face of the rubber plate 13 on the right side of the drawing. By aligning, it is possible to investigate the influence of the corner portion of the rubber plate 13 on the right side of the drawing on the measured strength of the test piece 12. Further, by exchanging the front and rear clamps, the influence of the corner portion of the rubber plate 13 on the left side of the drawing can be examined.
Further, in the present embodiment, the push plate 14 is configured to be capable of moving stepwise in the direction along the longitudinal direction of the test piece 12, but it may be configured to be capable of moving continuously.

[0008]

Since the present invention is a core strength tester simulating the impact of molten metal in the casting process, it is not necessary to perform actual casting using a prototype of the core, and therefore casting equipment is required. It is a tester that can evaluate the molten metal impact resistance of the core in a short time and at low cost.

[Brief description of drawings]

FIG. 1 is a partial sectional front view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a sectional view taken along the line CC in FIG.

FIG. 5 is a diagram showing an example of the relationship between the bending strength of the sand core and the limit angle of the arm.

[Explanation of symbols]

1 ... Base plate 2 ... Strut 3
… Upper plate 4… Bearing 5… Shaft 6
… Arm 7… Weight 8… Coupling 9
… Tachometer 10… Clamp 10a… Groove 1
1 ... Block 12 ... Specimen 13 ... Rubber plate 1
4 ... Push plate 14a ... Convex strip 15 ... Clamping bolt 1
6 ... Positioning bolt

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location G01M 7/08 (72) Inventor Ebisawa Kasujuo 15 Whale Ishinta, Kawagoe City, Saitama Prefecture 1 Sun Mansion Atre Kawagoe 306

Claims (2)

[Claims] 1. A weight is fixed to one end of an oscillating arm, a sand core specimen is arranged across a passage through which the one end of the arm passes, and one end of the specimen or A core strength tester in which elastic members are arranged on both sides of both ends, and a pressing member is arranged behind at least one of the elastic members on both sides to sandwich and fix the test piece. 2. The core strength tester according to claim 1, wherein the pressing member is arranged so as to be movable continuously or stepwise in a direction along the longitudinal direction of the test piece.