A method for grabbing a 3D printed sand mold

Abstract

The present application relates to a kind of 3D printing sand mold grabbing method, especially truss automatically grabs 3D printing sand mold group core hoisting structure, casting from bottom to top includes lower sand box, middle sand box and upper sand box, lower sand box includes bottom sand mold, middle sand box includes intermediate sand mold, upper sand box includes upper sand mold, hoisting grabbing structure is arranged in bottom sand mold, intermediate sand mold and upper sand mold in sequence respectively, hoisting grabbing structure is length h's column, the length h of each hoisting grabbing structure is increased in sequence, so that the hoisting grabbing structure of sand box presents inverted ladder to realize the grabbing of truss.The present application overcomes the limitation of sand mold on truss when 3D printing sand mold is sanding and group core box closing, while effectively reducing the height of sand core / type, reducing sand iron ratio to achieve the purpose of reducing cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the automatic core assembly of 3D printing sand mold, especially to the truss automatic core assembly of 3D printing sand mold. BACKGROUND

[0002] Casting is a process of melting metal into liquid that meets certain requirements, pouring into a mold, and after cooling, solidification, cleaning treatment, getting a casting with predetermined shape, size and performance. In the process of sand mold pre-sand cleaning and core assembly, due to the limitation of the truss mechanism, the height of the sand mold must be increased to release the restriction of the sand mold on the truss. This increases the sand-iron ratio of the casting, causing waste of raw materials such as resin, curing agent and cleaning agent. Therefore, it is of great significance to release the restriction of the sand mold on the truss and reduce the cost.

[0003] 3D printing core is a core produced by 3D printing technology, that is, using 3D printer to process and stack layer by layer to produce 3D entity. 3D printing is not limited by shape and can print any shape except closed cavity. It can be said that the more complex the product is, the more suitable it is for 3D printing production. However, the sand mold produced by 3D printing is limited by the truss during sand cleaning and core assembly. The current measure is to increase the height of the sand mold to release the restriction of the sand mold on the truss. This method has a disadvantage: increasing the height of the sand mold increases the sand-iron ratio, which increases the cost. SUMMARY

[0004] The present application overcomes the limitation of the prior art in the 3D printing sand mold during sand cleaning and core assembly, and provides a 3D printing sand core grabbing method. The method uses a stepped lifting structure to solve the limitation of the truss during 3D printing sand core grabbing, and effectively reduces the height of the sand core / mold to reduce the sand-iron ratio and achieve the purpose of reducing cost.

[0005] Based on this, the present application provides the following technical solutions:

[0006] A 3D printing sand mold grabbing method, the casting includes a lower sand box, a middle sand box and an upper sand box from bottom to top, the lower sand box includes a bottom sand mold, the middle sand box includes a middle sand mold, and the upper sand box includes an upper sand mold, comprising the following steps:

[0007] A lifting grabbing structure is arranged on the bottom sand mold, the middle sand mold and the upper sand mold in sequence, and the lifting grabbing structure is a column with a length h,

[0008] The length h of each lifting grabbing structure is increased in sequence,

[0009] So that the lifting grabbing structure of the sand box presents an inverted ladder shape to realize the grabbing of the truss.

[0010] In one embodiment, the hoisting and grabbing structure is arranged along the length direction of the sand mold.

[0011] In one embodiment, the position where the hoisting and grabbing structure contacts the sand mold is chamfered with an R10.

[0012] In one embodiment, the bottom sand mold is provided with a hoisting and grabbing structure one with a length of h1, and the hoisting and grabbing structure is increased by a length of δ; the increased length δ is greater than or equal to the length h1 of the hoisting and grabbing structure one.

[0013] In one embodiment, the middle sand mold is provided with a hoisting and grabbing structure two with a length of h2, and the length h2 of the hoisting and grabbing structure two is the sum of the length h1 of the hoisting and grabbing structure one and the increased length δ.

[0014] In one embodiment, the upper sand mold is provided with a hoisting and grabbing structure three with a length of h3, and the length h3 of the hoisting and grabbing structure three is the sum of the length h1 of the hoisting and grabbing structure one and twice the increased length δ.

[0015] The beneficial effects of the technical scheme of the present application mainly lie in that the hoisting and grabbing structure is arranged on the sand mold structure in a stepped manner, and the relationship between the stepped lengths is determined, so as to reduce the height of the sand mold, effectively reduce the sand-iron ratio, and save costs; the hoisting and grabbing structure in a stepped manner eliminates the restriction of the sand mold on the truss; and the problem that the core cannot be assembled due to the too low sand mold is solved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 Fig. 1 is a diagram of the hoisting and grabbing structure arranged on the sand mold;

[0017] Figure 2 Fig. 4 is a longitudinal schematic view of A-A;

[0018] Figure 3 Fig. 5 is a schematic view of the sand mold after the core is assembled;

[0019] Figure 4 Fig. 6 is an enlarged view of part C.

[0020] BRIEF DESCRIPTION OF DRAWINGS

[0021] hoisting and grabbing structure - 100, hoisting and grabbing structure one - 110, hoisting and grabbing structure two - 120, hoisting and grabbing structure - 130, sand mold - 200, bottom sand mold - 210, middle sand mold - 220, upper sand mold - 230, tray - 300, parting surface - 400 DETAILED DESCRIPTION

[0022] For the purposes of promoting an understanding of the principles of the application, reference will now be made to the embodiments illustrated in the drawings. There is shown by way of illustration a preferred embodiment of the application. However, it should be understood that the application can be practiced in a variety of ways and that the illustration is not intended to limit the application in any way. Rather, the purpose of the illustration is to make the disclosure more thorough and complete.

[0023] A production of a cast product, a sand core is produced by a 3D printing method, and the sand core needs to be grabbed by a truss during core assembly or process, but due to the limitation of the clamping jaw of the truss during grabbing, the truss grabber will interfere with the bottom of the sand core or sand mold, and the present application provides a grabbing method for 3D printed sand mold. Figure 1 and Figure 2 In the production process of the castings, according to the processing, process and quality requirements of the product, the pouring direction and position of the castings are determined, and the parting surface 400 is set according to the structure of the castings, so as to divide the castings into several sand molds 200. The hoisting and grabbing structure 100 is arranged at the symmetrical position of the sand mold 200, the hoisting and grabbing structure 100 is arranged in the length direction of the sand mold 200, and the mass center of the hoisting and grabbing structure 100 and the sand mold 200 are arranged on the same axis, wherein the distance L from the center of the lowermost hoisting and grabbing structure 100 close to the tray 300 to the top surface of the tray is not less than 125mm, and the distance is adjusted in the height direction according to the clamping jaw. Combined with Figure 1 and Figure 2 The hoisting and grabbing structure 100 arranged on the sand mold is a column structure, as can be seen from the cross section, the root of the hoisting and grabbing structure 100 is rounded with a radius R10, so as to reduce the shear force between the hoisting and grabbing structure 100 and the sand mold, and ensure that the sand mold is not easily damaged during grabbing.

[0024] Further, in the embodiment of the present application, referring to Figure 3 After the structure of the cast product is divided, the sand mold includes a bottom sand mold 210, a middle sand mold 220 and an upper sand mold 230. According to the size of the truss, the hoisting and grabbing structure I 110 is arranged on the bottom sand mold 210. The length of the hoisting and grabbing structure I 110 is h1 along the length direction of the sand mold, and the length h1 of the hoisting and grabbing structure I 110 is determined according to the depth of the truss clamping jaw.

[0025] To ensure that the lifting structure provided on the intermediate sand mold 220 does not interfere with the normal core assembly of the truss, a lifting and grabbing structure two 120 is provided on the intermediate sand mold 220, and the length of the lifting and grabbing structure two 120 is increased compared to the length of the lifting and grabbing structure one 110. Specifically, the length h2 of the lifting and grabbing structure two 120 is the length h1 of the lifting and grabbing structure one plus an increase length δ, that is, h2 = h1 + δ. In the present application, the selection of the parameter increase length δ is comprehensively considered. The upper lifting and grabbing structure is lengthened relative to the lower lifting and grabbing structure. If the increase length δ is too large, it will affect the strength of the sand mold, and the sand mold is easy to break; at the same time, it will affect the center of mass of the sand mold, causing the center of the lifting and grabbing structure and the center of mass of the sand mold not to be on the same axis, which will also affect the strength of the sand mold, and more will cause the service life of the truss to be reduced due to the imbalance of the center of gravity; If the increase length δ of the lifting handle is too large, it will increase the sand-iron ratio of the casting. If the increase length δ is too small, that is, δ is less than h1, the sand mold will interfere with the lifting structure of the lower box during core assembly, and the core assembly cannot be realized. If the increase length δ is greater than or equal to h1, the increase length δ can be set according to the actual production situation. When the increase length δ is set to be greater than or equal to h1 and less than h1 plus 5 cm, the optimal range of δ is h1 + 5 > δ ≥ h1, and the effect of grabbing is best.

[0026] Further, a lifting and grabbing structure three 130 is provided on the upper sand mold 230 to realize non-interference with normal core assembly during grabbing. The length h3 of the lifting and grabbing structure three 130 is also increased. Specifically, the length h3 of the lifting and grabbing structure three is increased by the increase length δ based on the length h2 of the lifting structure two 120, that is, h3 = h2 + δ = h1 + 2δ. At this time, the lifting and grabbing structure and the truss do not interfere with each other, which can effectively eliminate the restriction of the sand mold on the truss, so that the height of the sand mold does not need to be increased to complete the grabbing. At the same time, the sand-iron ratio of the sand mold with the length of the above lifting and grabbing structure is further reduced.

[0027] Reference Figure 3 and Figure 4The whole sand mold includes a bottom sand mold 210, a middle sand mold 220, and an upper sand mold 230, and the core is assembled. The upper sand mold 210 is provided with a lifting and grabbing structure one 110 with a length h1, the middle sand mold 220 is provided with a lifting and grabbing structure two 120 with a length h2, and the upper sand mold 230 is provided with a lifting and grabbing structure three 130 with a length h3. The length h2 is increased by a length delta based on the length h1, and the length h3 is increased by a length delta based on the length h2, thereby forming a stepped structure from top to bottom. The stepped structure eliminates the restriction of the sand mold on the truss, and is also applicable to relatively short sand molds. When the number of sand molds is larger, the stepped grabbing and lifting structure can also be used, and the length of the lifting and grabbing structure is increased from bottom to top. If there are n sand molds, the length hn of the lifting and grabbing structure of the uppermost sand core or sand mold is equal to h1+(n-1)delta.

[0028] It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present. As used herein the terms "vertical", "horizontal", "left", "right", "top", "bottom", "bottom end", "top end", and the like are used for description only and are not intended to be limiting.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0030] The technical features of the above-described embodiments can be combined in any manner. To make the description brief, all possible combinations of the technical features in the above-described embodiments are not described, but it should be considered that any combination of the technical features is within the scope of the present disclosure as long as the combination does not cause contradiction.

[0031] The above-described embodiments only express several embodiments of the present application, and the description is relatively specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A method of gripping a 3D printed sand mold, comprising a bottom sand mold, an intermediate sand mold and an upper sand mold, characterized in that, It comprises the following steps: The hoisting and grabbing structure is arranged on the bottom sand mold, the middle sand mold and the upper sand mold in sequence, and the length of each hoisting and grabbing structure is increased from bottom to top; The bottom sand mold is provided with a hoisting and grabbing structure one with a length of h1; The hoisting and grabbing structure is increased by a length of δ, and the increased length δ is greater than or equal to the length h1 of the hoisting and grabbing structure one; The middle sand mold is provided with a hoisting and grabbing structure two with a length of h2, and the length h2 of the hoisting and grabbing structure two is the sum of the length h1 of the hoisting and grabbing structure one and the increased length δ; The upper sand mold is provided with a hoisting and grabbing structure three with a length of h3, and the length h3 of the hoisting and grabbing structure three is the sum of the length h1 of the hoisting and grabbing structure one and twice the increased length δ; Thus, the hoisting and grabbing structure of the sand mold is in the form of inverted ladder to realize the grabbing of the truss.

2. The method of claim 1, wherein, The hoisting and grabbing structure is arranged along the length direction of the sand mold and is symmetrically arranged on both sides of the sand mold.

3. The method of claim 1, wherein, The position where the hoisting and grabbing structure contacts with the sand mold is chamfered.

Images