WO2002000370A1

WO2002000370A1 - A process and an apparatus of mold-making or core-making

Info

Publication number: WO2002000370A1
Application number: PCT/CN2000/000423
Authority: WO
Inventors: Shengyi Qin
Original assignee: Shengyi Qin
Priority date: 2000-06-13
Filing date: 2000-11-15
Publication date: 2002-01-03
Also published as: CN1175948C; AU1266701A; CN1275455A

Abstract

The invention provides a process and an apparatus of mold-making or core-making, it is characterized in that injecting the surface layer mixture consisting of fine sands and the back layer mixture consisting of coarse sands into the mold or core-box, the surface layer mixture adhering to the surface of mold or core box, and together with the back layer mixture hardening into a whole mold or core. Compared with the existing technology, the invention has increased the speed and precision of molding or core-making, adapted to large-scale industry production, and also improved the precision of castings.

Description

Composite molding (core) process and device

Technical field

The invention relates to a composite molding (core) process and device, which is to inject a fine-grained surface layer mixture into the inner cavity of the mold (core) box and a back layer mixture with a coarser grain size than the surface layer mixture, so that the surface The layer mixture is adhered to the surface and hardened with the back layer mixture to form a complete core to improve the speed and accuracy of the molding (core), to adapt to large-scale industrial production, and to improve the accuracy of castings. ' Background technique

Applying a coating on the surface of the core in casting production is an effective means to prevent metal penetration, sand sticking, and improve the high surface finish of the casting. In order to improve the coating quality, people use the pouring method, the rain method, the airless spray method and the electrostatic spray method for coating. However, these methods are done by brushing, spraying or dipping the coating after the mold (core) is made. Because the coating is applied in an unconstrained state, defects such as brush marks, flow, and stacking can be formed on the surface, and the thickness of the coating affects the dimensional accuracy of castings, especially complex and fine castings. To solve this problem, Japan invented the K-Y method in the 1970s. By the end of the 1980s, it had developed from a heating core box to a new K-Y method using microwave hardening. In the K-Y method, the coating is directly applied to the surface of the core box, and then the core sand is filled. The anticorrosion by microwave heating causes the coating and the core sand to harden and combine with each other under the constraints of the mold. The coating will be transferred when the mold is lifted. To the surface of the sand core, the coating can accurately reproduce the surface accuracy of the core box, and obtain precise and clean castings. A similar method appeared in the Soviet Union in the 1980s, namely the "precision coating method", which applied the coating to a core box heated to 240 ^Q C and then filled with resin-coated sand to produce a precision coating with coating. Sand core. Japan also invented a method, which is to apply paint on the surface of the model, and then fill it with cement fluid sand. By passing current between the model and the sand box, the paint is transferred to the surface of the sand mold when it is lifted, resulting in a precise, smooth surface. Mold. Chinese patent application CN1065612A discloses a self-hardening transfer coating method. The self-hardening coating is directly coated on the surface of a model or a core box, and then filled with water glass sand. After compacting, it is blown with C0 _{2 to} harden. The coating is transferred from the surface of the mold to the surface of the sand core, which can avoid defects such as flow, brush marks and accumulation in the traditional coating method. This method breaks through the heating hardness of the K-Y method and the precision coating method. The coating can accurately reproduce the surface of the mold. This method can be used to produce general castings and some precision castings that require high surface quality and dimensional accuracy. However, the above paints are all solvent-based paints, which contain organic solvents or water, which makes the manufacture, storage, and transportation of the paint extremely inconvenient. In addition, the coating is completed by brushing, which is inefficient, and Solvent-based coatings need to be dried after coating, which is not suitable for efficient, high-quality mass production. Summary of the invention

The purpose of Ming is to overcome the above-mentioned shortcomings of the prior art, to provide a composite molding (core) process and device, improve the efficiency and quality of core making, improve the dimensional accuracy and surface finish of castings, and adapt to large-scale large-scale production.

The composite molding (core) process of the present invention is to inject a fine-grained surface layer mixture and a back layer mixture with a coarser grain size than the surface layer mixture into the core box, so that the surface layer mixture adheres to the surface and is mixed with the back layer. The material is hardened together to form a complete core.

The molding (core) device of the present invention includes a core box, at least one surface layer sanding head and a back layer sanding head, and the surface layer sanding head has a surface layer storage cavity on the surface layer. The back-layer mixture shot head has a back-layer mixture storage cavity, and the two storage chambers can communicate with the inner cavity of the core box.

Compared with the prior art, the core-making process of the present invention is simple and efficient, and a core with a dense surface can be obtained without using a solvent-based coating, which meets the requirements of the size and finish of the casting. The method of the present invention is particularly suitable for the core. Large-scale production.

In the present application, the surface layer mixture refers to a mixture of fine particles not containing a solvent (such as water or an organic solvent), which cannot form a coating on the surface of the core by coating. Overview of the drawings

il¾ a schematic diagram of an embodiment of a device used in the process of the present invention;

Fig. 2 is a schematic diagram of another embodiment of the apparatus used in the process of the present invention.

The reference numerals in the drawings indicate: 1 core box, 2 surface layer shot sanding head, 3 back layer shot sanding head, 5 surface layer shot, 6 back layer shot, and cavity. Best Mode of the Invention

The device of the present invention comprises a core box 1, at least one surface layer sanding head 2 and a back layer sanding head 3, and the surface layer sanding head 2 has a surface layer storage cavity, The back-layer mixture shot head 3 has a back-layer mixture storage chamber, and the two storage chambers can communicate with the inner chamber 7 of the core box 1.

FIG. 1 shows a structure in which the surface layer shot head 2 and the back layer shot head 3 are integrated, wherein the back layer shot member 3 is located inside the surface layer shot member 2 . During molding (core) operation, both the surface layer mixture and the back layer mixture can be sprayed first. The position shown in the drawing is a state in which the core box is aligned with the shot head and ready for shot shot.

Fig. 2 shows a structure of a composition of a surface layer shot blasting head 2 and a back layer shot blasting head 3. The core box 1 is located on the table and can be moved relative to the shot head 2 or 3.

Both the shot head 2 and the shot head 3 are connected to a pressure air source (not shown).

The fine-grained surface layer mixture is injected into the core box before the back layer mixture, and the back layer mixture is diffused toward the surface of the inner cavity of the core box when the back layer mixture is injected into the back layer mixture, and the back layer is mixed. The material is filled from the middle of the inner cavity of the core box, so that the surface layer mixture is distributed on the surface of the back layer mixture to be hardened.

The fine-grained surface layer mixture and the back layer mixture can also be injected into the core box at the same time. The surface layer mixture is injected along the periphery of the inner cavity of the core box, and the back layer mixture is injected along the middle of the inner cavity of the core box. , So that the surface layer mixture is distributed on the surface of the back layer mixture to be hardened.

The core box 1 may be a hot core box, and the surface layer mixture and the back layer mixture are coated sand for a hot core box.

The surface layer mixture and the back layer mixture may be wet-coated sand.

The core box may be a cold core box, and the surface layer mixture and the back layer mixture may be a core sand mixture for a cold core box.

The core box may also be a warm core box, and the surface layer mixture and the back _¾ layer mixture are core sand mixtures for a warm core box. ^¾ The surface layer mixture and the back layer mixture may have the same or different kinds of aggregates or binders.

The back layer mixture is water glass sand, and the surface layer mixture may be a mixture containing a water glass binder, or a mixture containing other binders or no binders.

The surface layer mixed material shot head and the back layer mixed material shot head have an integrated structure.

The surface layer mixed material shot head and the back layer mixed material shot head are of a split structure.

The back layer aggregate can be silica sand, quartz sand, magnesia, zircon sand, chromite sand or a mixture of these sands.

The aggregate of the surface layer mixture may also be silica sand, quartz sand, magnesia, zircon sand, chromite sand, or a mixed sand thereof.

The back layer aggregate and the surface layer aggregate may be the same or different, depending on the specific requirements of the casting.

Wet coated sand can be the material disclosed in CN1033743C, or it can be other forms of coated sand, such as formed by adding silicone oil or organic fat after adding phenolic resin binder in the conventional coated sand manufacturing process. Wet coated sand.

The dry coated sand can be a conventional hot box coated sand or a high temperature resistant coated sand. Example 1:

The core box 1 is a hot core box. Firstly, a fine-grained surface layer mixture 5 is injected into the core box 1, and then a back layer mixture 6 having a coarser grain size than the surface layer mixture is injected to make the surface layer mixture 5 adhere to The surface and the back layer mixture 6 harden to form a complete core. The back layer mixture is a conventional shell-type coated sand, and the top layer mixture is a conventional fine-grained shell-shaped coated sand. When the layer mixture is injected, the surface layer mixture injected first diffuses to the surface of the inner cavity of the core box, and the back layer mixture is injected from the middle of the inner cavity of the core box, so that the surface layer mixture is distributed on the surface of the back layer mixture. Hardened.

Example 2:

The core box 1 is a hot core box, and the fine particle surface layer mixture 5 and the back layer mixture 6 are simultaneously injected into the core box 1 so that the surface layer mixture 5 adheres to the surface and hardens with the back layer mixture 6 Into a complete core, wherein the back layer mixture is a conventional shell-shaped coated sand, which is injected from the middle of the inner cavity of the core box, and the surface layer mixture is a conventional fine-grained shell-shaped coated sand, from the inner cavity of the core box Shot around.

Example 3: Except that the surface layer mixture uses a mixture that does not contain a binder, the other embodiments are the same as those in Examples 1 and 2. Example 4:

Except that the surface layer mixture uses the wet-coated sand in CN1033743C, the others are the same as those in Examples 1 and 2.

Example 5:

Except that the surface layer mixture and the back layer mixture use the wet-coated sand in CN1033743C, the others are the same as those in Examples 1 and 2.

Example 6:

Except that the surface layer mixture does not contain a binder and the back layer mixture uses the wet-coated sand in CN1033743C, the others are the same as those in Examples 1 and 2.

Example 7:

The core box 1 is a cold core box. Firstly, a fine-grained surface layer mixture 5 is injected into the core box 1, and then a back layer mixture 6 having a coarser grain size than the surface layer mixture is injected to make the surface layer mixture 5 adhere to The surface and the back layer mixture 6 are hardened into a complete core. The back layer mixture and the surface layer mixture are conventional cold hard resin sand mixtures. When the back layer mixture is injected into the back layer mixture, the first shot is made. The surface layer mixture diffuses to the surface of the inner cavity of the core box, and the back layer mixture is injected from the middle of the inner cavity of the core box, so that the surface layer mixture is distributed on the surface of the back layer mixture to be hardened.

Example 8:

The core box 1 is a cold core box, and the fine particle surface layer mixture 5 and the back layer mixture 6 are simultaneously injected into the core box 1 so that the surface layer mixture 5 adheres to the surface and is hardened together with the back layer mixture 6 A complete core, in which the back layer mixture and the surface layer mixture are conventional cold hard resin sand mixture. The surface layer mixture is injected from the periphery of the inner cavity of the core box, and the back layer mixture is injected from the inner cavity of the core box. Middle shot.

Example 9:

Except that the surface layer mixture is a mixture without a binder, it is the same as in Example 8. Example 10:

The core box 1 is a warm core box. First, a fine-grained surface layer mixture 5 is injected into the core box 1, and then a back layer mixture 6 having a coarser grain size than the surface layer mixture is injected, so that the surface layer mixture 5 is attached to The surface and the back layer mixture 6 are hardened into a complete core. The back layer mixture and the surface layer mixture are conventional resin sand mixtures for warm core boxes. When the back layer mixture is injected into the back layer mixture, it is shot first. Blending The material diffuses to the surface of the inner cavity of the core box, and the back layer mixture is injected from the middle of the inner cavity of the core box, so that the surface layer mixture is distributed on the surface of the back layer mixture to be hardened.

Example 11:

The core box 1 is a warm core box, and a fine-grained surface layer mixture 5 and a coarse-grained back layer mixture 6 are simultaneously injected into the core box 1 so that the surface layer mixture 5 is adhered to the surface and the back layer mixture 6— It is hardened into a complete core, where the back layer mixture and the surface layer mixture are conventional resin sand mixtures for warm core boxes. The surface layer mixture is injected from the periphery of the inner cavity of the core box, and the back layer mixture is from the core. The middle of the box cavity is injected.

Example 12:

Except that the surface layer mixture uses a mixture that does not contain a binder, the others are the same as those in Examples 10 and 11. Example 13:

The core box 1 is a cold core box. Firstly, a fine-grained surface layer mixture 5 is injected into the core box 1, and then a back layer mixture 6 having a coarser grain size than the surface layer mixture is injected to make the surface layer mixture 5 adhere to The surface and the back layer mixture 6 are hardened to form a complete core, wherein the back layer mixture and the top layer mixture are water glass sand. When the back layer mixture is injected into the back layer mixture, the first layer mixture is injected first. The surface of the inner cavity of the core box diffuses, and the back layer mixture is filled in from the middle of the inner cavity of the core box, so that the surface layer mixture is distributed on the surface of the back layer mixture and hardened by blowing CO ₂ .

Example 14:

Except that the surface layer mixture is a mixture without a binder, it is the same as in Example 13. Example 15:

The surface layer mixture and / or the back layer mixture are made of silica sand, quartz sand, magnesia, zircon sand, chromite sand, or a mixture of these sands.

Example 16:

The core shape is a cylindrical core with a diameter of 100 mm and a height of 90 mm, and the core box is a hot core box. The parting surface and the shot opening are in the middle of the core height. The surface layer mixture is 200 mesh zircon sand coated sand, the binder is phenol resin, the back layer mixture is '50 / 100 mesh silica sand coated sand, and the binder is phenol resin. Core making process: the core box Xianxiang ejection face layer material mixture, and then incident on the backing layer mixture, the shooting surface layer and the backing layer mixture Mixture interval of 30 seconds, the shooting results showed that pressure 0.6Mpa _o The surface layer mixture can be evenly distributed and hardened on the surface of the core. In FIG. 1 showing the device of the present invention, the surface layer sandblasting head 2 and the back layer sandblasting head 3 have a split structure, and after the surface layer sandblasting head 2 has shot sand into the core box 1 The back layer mixture shot head 3 is moved to the shot position above the core box 1, and the back layer mixture is injected into the core box.

FIG. 2 shows a structure in which the surface layer sanding head 2 and the back layer sanding head 3 are integrated, wherein the back layer sanding head 3 is located inside the surface layer sanding head 2 . During molding (core) operation, both the surface layer mixture and the back layer mixture can be sprayed first.

According to the process of the present invention, the surface layer and / or back layer mixture can also be injected into the core box from multiple positions or directions simultaneously or at intervals. According to the process of the present invention, it is also possible to use a multi-station sand blasting machine to spray and fill only one kind of mixture (surface layer mixture / or back layer mixture) at each station, that is, the core box is filled with the surface layer mixture. After the material is fed, it is moved to another station to fill the back layer mixture. Of course, the shot head can also be moved without the core box moving.

The above description with reference to the accompanying drawings and embodiments is merely illustrative and does not constitute a limitation on the present invention. Obviously, many modifications can be made on the basis of the present invention without departing from its essence.

Claims

Claim

1. A composite molding (core) process, characterized in that a fine-grained surface layer mixture and a back layer mixture having a coarser grain size than the surface layer mixture are injected into the core box to make the surface layer mixture adhere to the surface It is then hardened with the backing compound to form a complete core.

2. The composite molding (core) process according to claim 1, wherein the fine-grained surface layer mixture is injected into the core box before the back layer mixture.

3. The composite molding (core) process according to claim 1, wherein the fine-grained surface layer mixture and the back layer mixture are simultaneously injected into the core box, and the surface layer mixture is along the core box. The periphery of the cavity is injected, and the back layer mixture is injected along the middle of the inner cavity of the core box.

4. The composite molding (core) process according to claim 1, 2 or 3, characterized in that the core box is a hot core box, and the surface layer mixture and the back layer mixture are hot cores. Box with coated sand.

5. The composite molding (core) process according to claim 1, 2 or 3, characterized in that the surface layer mixture and the back layer mixture are wet-coated sand.

6. The composite molding (core) process according to claim 1, 2 or 3, wherein the core box is a cold core box, and the back layer mixture is a core sand mixed with a cold core box. material.

7. The composite molding (core) process according to claim 1, 2 or 3, characterized in that the core box is a warm core box, and the back layer mixture is a core sand mix for a warm core box. material.

8. The composite molding (core) process according to claim 1, 2 or 3, characterized in that the surface layer material and the back layer mixture have the same or different kinds of aggregates and binders.

9. The composite molding (core) process according to claim 1, 2 or 3, wherein the back layer mixture is water glass sand.

10. A molding (core) device, comprising a core box (1), characterized in that the device further comprises at least one surface layer sanding head (2) and a back layer sanding head (3) ), The surface layer mixing shot head (2) is provided with a surface layer storage cavity, and the back layer mixture shot head (3) is provided with a back layer mixing material storage cavity, and the two storage chambers may be It is in communication with the inner cavity (7) of the core box (1).

11. The device according to claim 8, characterized in that the surface layer sand-blasting head (2) and the back layer sand-blasting head (3) have an integrated structure, and the back layer sand-blasting head

(3) Located within the surface layer shot head (2).

12. The device according to claim 8, characterized in that the surface layer sandblasting head (2) and the back layer sandblasting head (3) are separate structures.