JPS6317560Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a molding box in which a mold box cavity is filled with gas-hardening foundry sand by suction, and a hardening gas is passed through the filled sand by suction to form a mold. This invention relates to a foundry sand pushing member.

In recent years, the applicant has developed a mold making method that does not require clamping of the mold box when filling the mold box with molding sand, and also allows hardening gas to be vented into the molding sand without any gas leaking from the mold box. It has been applied for and published. In this molding method, gas-curable molding sand is filled into the mold box cavity by suction.
Similarly, a curing gas is passed through the filling sand by suction to form a mold.

By the way, when molding a mold using the above-mentioned molding method, the molding box cavity is filled with molding sand by communicating and abutting the discharge port of the molding sand storage hopper with the sand supply hole of the molding box, and by suctioning and reducing the pressure inside the molding box cavity. However, when the outlet of the hopper is pulled up from the sand supply hole after filling with molding sand is completed, a small amount of sand remains in the sand supply hole.

The sand supply hole must be shaped before the hardening gas is vented, and this is done by inserting a pushing member into the sand supply hole. Because it also serves as a gas vent, it is necessary to remove the pushing member before venting the gas. However, in the method of filling molding sand into the mold box cavity by suction, the gas blowing nozzle is not inserted into the sand supply hole, and the sand supply hole has a wider opening than in the case of the blowing filling method. Therefore, during gas ventilation, the sand in the sand supply hole was often blown away, resulting in unevenness on the surface of the finished mold.

The present invention has been made to solve the above problems.

The present invention will be described in detail below based on an embodiment. The drawing shows a horizontally split mold box 1, with an upper mold box 2 and a lower mold box 3 having their respective mold surfaces joined to form a closed cavity 4. It is arranged.

A hollow chamber 5 is formed inside the lower mold box 3, and the hollow chamber 5 and the cavity 4 communicate with each other via a plurality of through holes 6. A vent plug (not shown) is fitted on the cavity 4 side of the through hole 6 to prevent the sand S in the cavity 4 from leaking into the hollow chamber 5. A through hole 7 communicating with the hollow chamber 5 is bored in one side wall of the lower mold box 3, and the through hole 7 is connected to a vacuum pump 9 via a conduit 8. Note that a valve 11 is provided in the middle of the conduit 8. The lower mold box 3 is also located inside the upper mold box 2.
Similarly, a hollow chamber 12 is formed, and the hollow chamber 1
2 and the cavity 4 communicate through a plurality of through holes 13 into which vent plugs (not shown) are fitted. The hollow chamber 12 is also located on one side wall of the upper mold box 2.
A through hole 14 leading to the through hole 14 is bored.
is connected to a curing gas supply device 17 via a conduit 16 in which a valve 15 is disposed. The cavity 4 is located at the center of the back of the upper mold box 2.
A sand supply hole 18 is formed that reaches the sand hole 18, and the sand supply hole 18 and the hollow chamber 12 are separated from each other by a partition wall. The sand supply hole 18 has a flange 19 formed at its upper end that can be engaged with the back surface of the upper molding box 2, and a lower end surface 20 that forms part of the wall surface of the cavity 4. A pushing member 21 is removably inserted therein.

The pushing member 21 has a plurality of ventilation holes 22 penetrating from the upper end surface to the lower end surface 20, and a vent plug (not shown) is fitted into the cavity 4 side of the ventilation holes 22. .

On the back side of the upper mold box 2 is a gutsing cover 2.
3 is removably placed so as to cover the pushing member 21. A through hole 24 is bored in one side wall of the gutting cover 23, and the through hole 24 is connected to the conduit 16 through a conduit 25.
It is connected with.

To mold a mold using the horizontal molding box 1 configured as described above, first, the molding sand S is sucked into the cavity 4 from the sand supply hole 18 of the upper molding box 2.
After filling the inside, the pushing member 21 is inserted into the sand supply hole 18. As a result, the residual sand in the sand supply hole 18 is shaped. Next, the pushing member 21
The gushing cover 23 is placed on the back surface of the upper mold box 2 so as to leave it as it is and cover the member 21. Furthermore, when the valve 15 of the curing gas supply device 17 and the valve 11 of the vacuum pump 9 are opened, a part of the curing gas enters the gashing cover 23 through the conduit 25 and the through hole 24, and further flows through the passage of the pushing member 21. It enters the mold box cavity 4 through the air hole 22, and the other part enters the mold box cavity 4 through the conduit 16 and the through hole 14, the hollow chamber 12 and the through hole 13 of the upper mold box 2. Then, it is discharged into the atmosphere through the through hole 6 of the lower mold box 3, the hollow chamber 5, the through hole 7, the conduit 8, a neutralization device and a vacuum pump 9 (not shown). In this way, the hardening gas evenly contacts the sand in the mold box cavity 4 and hardens it.

As is clear from the above description, in the present invention, a plurality of ventilation holes are formed in a pushing member that is inserted into a sand supply hole of a molding box, passing through it from its upper end surface to its lower end surface. Therefore, even after filling the mold box cavity with the mold box and shaping the filled sand by inserting the pushing member into the sand supply hole, the hardening gas can be vented without removing the member. Therefore, during gas passage, the sand in the sand supply hole is pressed by the pushing member and is not blown away, so that unevenness does not occur on the surface of the completed mold.

In addition, once the pushing member is inserted into the sand supply hole,
There is no need to remove it until gas flow is complete, which simplifies the process.

[Brief explanation of the drawing]

The drawing is a sectional view of a horizontally split mold box in which the pushing member according to the present invention is inserted and hardening gas is supplied. 1: Horizontal split mold box, 2: Upper mold box, 3: Lower mold box, 4: Mold box cavity, 9: Vacuum pump, 1
7: Hardening gas supply device, 18: Molding sand supply hole, 1
9: flange, 20: lower end surface, 21: pushing member, 22: ventilation hole, 23: gutsing cover.

Claims (1)

[Scope of utility model registration request] A flange 1 that can be inserted into the sand supply hole 18 of the molding box 1 and that can be locked to the upper surface of the molding box 1 at the upper end.
9 is formed, and the lower end surface 20 is formed so as to constitute a part of the wall surface of the mold box cavity 4, and a plurality of ventilation holes 22 are bored through the mold box cavity 4 from the upper end surface to the lower end surface 20. A molding sand pushing member for a molding box, characterized by: