Vacuum negative pressure sand box

Abstract

The utility model discloses a vacuum negative pressure sand box, which relates to the technical field of evanescent mode casting and comprises a box body, a vacuum channel is arranged on the outer wall of the box body, a plurality of vacuumizing windows are arranged at the positions of the box body corresponding to the vacuum channel, and an inner cavity of the box body is communicated with the vacuum channel through the vacuumizing windows. A plurality of stainless steel rods used for intercepting a sand mold are arranged in the vacuumizing window and are arranged in parallel at intervals, and an air exhaust nozzle used for being connected with vacuumizing equipment is arranged on the vacuum channel; according to the vacuum negative-pressure sand box, the stainless steel bars arranged at intervals are used for replacing stainless steel meshes to form the suction channel, so that the structural strength is high, the vacuum negative-pressure sand box can be effectively prevented from being burnt by high-temperature molding sand, and the service life of the vacuum negative-pressure sand box is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of lost foam casting, in particular to a vacuum negative pressure sand box. Background Art

[0002] Lost foam casting is a sand casting process. The general sand casting process uses clay sand and metal or wooden models. After molding, the model must be taken out of the sand mold, and then the mold is closed to form a cavity in the sand mold for metal pouring. Lost foam casting uses dry sand and polymer resin foam as a model. The model does not need to be taken out after being buried in the sand during molding. During pouring, the resin foam pattern will vaporize when it comes into contact with the molten metal. At this time, negative pressure is applied to the lost foam, and the gas generated by the vaporization of the pattern is extracted with a vacuum pump. The liquid metal occupies the position of the model and the pouring is completed. Lost foam casting does not require mold removal, no parting surface, and no sand core. Therefore, the casting has no flash burrs and no demolding slope, which reduces the dimensional error caused by the sand core combination. It is a nearly zero-residue precision forming process.

[0003] The lost foam vacuum sand box, also called the vacuum negative pressure sand box, is a sand box unique to lost foam casting. It can improve the quality of castings and reduce unnecessary energy consumption. The traditional vacuum negative pressure sand box is divided into an inner sand box and an outer sand box. There is a certain distance between the inner and outer boxes to form a gap, which is used as an air channel for vacuuming. A window is opened in the middle of the four walls and the bottom of the inner box, and a 200-mesh stainless steel mesh is installed on it. The stainless steel mesh can block the molding sand, and the gap between the inner and outer boxes and the inner box are ventilated. The sand and model are placed in the inner box for molding, and the vacuum pump is installed in the vacuum hole of the outer box. During pouring, the model gasifies and produces a large amount of gas. These gases are drawn away along the line of the sand mold in the inner box - the stainless steel mesh on the inner box wall - the gap between the inner box and the outer box - the vacuum pump, and the vacuum negative pressure ensures the stability of the sand mold shape and better controls the density and strength of the sand mold. However, in actual use, the stainless steel screen is easily damaged. After the stainless steel screen is damaged, it needs to be replaced with a new stainless steel mesh. If it is not replaced in time, it will affect the quality of vacuuming, and the screen always needs maintenance, which is costly and troublesome to operate.

[0004] Therefore people are in urgent need of a vacuum negative pressure sand box with long service life. Summary of the invention

[0005] The utility model aims to provide a vacuum negative pressure sand box to solve the problems existing in the above-mentioned prior art, and utilizes stainless steel bars arranged at intervals to replace the stainless steel mesh to form a suction channel to increase the service life of the vacuum negative pressure sand box.

[0006] To achieve the above-mentioned purpose, the utility model provides the following solution: the utility model provides a vacuum negative pressure sand box, including a box body, a vacuum channel is arranged on the outer wall of the box body, a plurality of vacuum windows are arranged at the position corresponding to the vacuum channel, the inner cavity of the box body is connected with the vacuum channel through the vacuum windows, a plurality of stainless steel bars for intercepting sand molds are arranged in the vacuum windows, the plurality of stainless steel bars are arranged in parallel and spaced apart, and a suction nozzle for connecting to a vacuum device is arranged on the vacuum channel.

[0007] Preferably, channel steels are fastened on the outer side wall and the outer bottom wall of the box body, and the vacuum channel is formed between the channel steels and the box body.

[0008] Preferably, a plurality of lifting ears are provided on the outer side wall of the box body.

[0009] Preferably, the lifting lug passes through the channel steel and is connected to the box body.

[0010] Preferably, reinforcing ribs are provided between the lifting ears and the box body.

[0011] Preferably, the open end of the channel steel is welded and sealed to the box body.

[0012] Preferably, a plurality of the vacuum extraction windows are evenly distributed on the outer side wall and the outer bottom wall of the box body.

[0013] Preferably, the stainless steel rod is welded to the vacuum window.

[0014] Preferably, a reinforcing angle steel is provided on the bottom edge of the box body.

[0015] Preferably, a reinforcing channel steel is provided on the top of the box body.

[0016] Compared with the prior art, the utility model mainly achieves the following technical effects:

[0017] The suction channel is formed by replacing the stainless steel mesh with stainless steel rods arranged at intervals. It not only has high structural strength, but also can effectively avoid being burned by high-temperature sand, so as to increase the service life of the vacuum negative pressure sand box.

[0018] Compared with the prior art, other solutions of the utility model have achieved the following technical effects:

[0019] The vacuum channel is formed by using channel steel, which reduces the volume of the vacuum channel, can effectively increase the negative pressure in the vacuum channel, and improve the suction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] Figure 1 This is a schematic diagram of the structure of the vacuum negative pressure sand box of the utility model;

[0022] Figure 2 It is a schematic diagram of the top view of the vacuum negative pressure sand box of the utility model;

[0023] Figure 3 It is a left view structural schematic diagram of the vacuum negative pressure sand box of the utility model;

[0024] Among them, 1. Box body; 2. Vacuum window; 3. Vacuum channel; 4. Stainless steel rod; 5. Channel steel; 6. Lifting ear; 7. Reinforcement rib; 8. Reinforced angle steel; 9. Reinforced channel steel; 10. Vacuum nozzle. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] The utility model aims to provide a vacuum negative pressure sand box to solve the problems existing in the prior art, and utilizes stainless steel bars arranged at intervals to replace the stainless steel net to form a suction channel to increase the service life of the vacuum negative pressure sand box.

[0027] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0028] Please refer to Figures 1 to 3As shown, a vacuum negative pressure sand box is provided, including a box body 1, and a vacuum channel 3 is arranged on the outer wall of the box body 1. Specifically, the vacuum channel 3 is arranged on the outer side wall and the outer bottom wall of the box body 1, and a plurality of vacuum windows 2 are arranged at the position of the box body 1 corresponding to the vacuum channel 3. The inner cavity of the box body 1 is connected with the vacuum channel 3 through the vacuum window 2, and a plurality of stainless steel rods 4 are arranged in the vacuum window 2. Preferably, the stainless steel rod 4 is welded to the vacuum window 2, and the plurality of stainless steel rods 4 are arranged in parallel and spaced apart. The spacing distance should ensure that the sand in the box body 1 can be effectively intercepted and have a ventilation effect at the same time. Stainless steel is selected according to the actual casting temperature, and its resistant temperature should be greater than the casting temperature to prevent it from being scalded by sand. A vacuum nozzle 10 is arranged on the vacuum channel 3, and the vacuum nozzle 10 is used to connect with the vacuum pumping equipment. The vacuum pumping equipment generates suction to the box body 1 through the vacuum nozzle 10 and the vacuum channel 3, so as to extract the gas generated by the gasification of the pattern; the device uses the stainless steel rods 4 arranged at intervals to replace the stainless steel mesh in the prior art to form a suction channel, and uses the thicker characteristics of the stainless steel rods 4 themselves to improve the structural strength, and can effectively avoid being scalded by high-temperature molding sand, so as to increase the service life of the vacuum negative pressure sand box.

[0029] In this embodiment, the conventional outer box is eliminated and replaced by a channel steel 5. Specifically, the channel steel 5 is provided on the outer side wall and the outer bottom wall of the box body 1, and the vacuum channel 3 is formed between the channel steel 5 and the box body 1. The width of the inner cavity of the channel steel 5 can be equal to or slightly larger than the length of the vacuum window 2 along the width direction of the channel steel 5. That is, when the channel steel 5 is provided outside the vacuum window 2 to form the vacuum channel 3, the distance between the inner walls on both sides of the channel steel 5 and the vacuum window 2 is very small, or the inner walls on both sides of the channel steel 5 are flush with the inner side walls of the vacuum window 2. By replacing the outer box with the channel steel 5, the volume of the vacuum channel 3 can be reduced, the negative pressure in the vacuum channel 3 can be effectively increased, and the suction effect can be improved.

[0030] When the inner space of each channel steel 5 is used as a separate vacuum channel 3, an exhaust nozzle 10 needs to be provided on each channel steel 5. In order to reduce the number of exhaust nozzles 10, the inner cavities of several channel steels 5 can be interconnected, and several channel steels 5 are distributed on the box body 1 in the form of a grid. When two channel steels 5 intersect vertically and are not located on the same surface, that is, when the two channel steels 5 are connected at the corners of the box body 1, it is only necessary to weld and seal the two ports; when the two channel steels 5 are located on the same horizontal plane or vertical plane, it is necessary to open a connecting hole on the side wall of one of the channel steels 5, and the end of the other channel steel 5 is connected to the connecting hole, so that the internal spaces of the two channel steels 5 are connected, and the connecting point is welded and sealed.

[0031] The open end of the channel steel 5 is welded and sealed to the box body 1 to prevent the gap from affecting the suction effect.

[0032] In order to improve the uniformity of suction, a plurality of vacuum windows 2 are arranged evenly distributed on the outer side wall and the outer bottom wall of the box body 1 .

[0033] Since the whole sand box needs to be transported, a plurality of lifting ears 6 need to be provided. Specifically, the plurality of lifting ears 6 are provided on the outer side wall of the box body 1 .

[0034] Part or all of the lifting ears 6 can be arranged to pass through the channel steel 5 and be connected to the box body 1. Avoidance holes are arranged on the channel steel 5 at positions corresponding to the lifting ears 6. The avoidance holes and the lifting ears 6 need to be sealed. The sealing method is welding sealing to improve the structural strength.

[0035] A reinforcing rib 7 is arranged between the lifting ear 6 and the box body 1. When the lifting ear 6 is connected to the box body 1 through the channel steel 5, a corresponding through-hole is arranged on the channel steel 5 for the reinforcing rib 7 to pass through and extend to the outside. The reinforcing rib 7 and the through-hole are sealed. The reinforcing rib 7 can effectively improve the connection strength between the lifting ear 6 and the box body 1.

[0036] The reinforcing rib 7 and the through-hole are sealed by welding to further improve the structural strength.

[0037] A reinforcing angle steel 8 is provided at the bottom edge of the box body 1 to improve the structural strength of the box body 1 . Reinforcing angle steels 8 may also be provided at the four corners of the box body 1 .

[0038] A reinforcing channel steel 9 is provided on the top of the box body 1 . The reinforcing channel steel 9 is arranged in an annular structure on the outer peripheral side of the top of the box body 1 to improve the structural strength of the top of the box body 1 .

[0039] In this embodiment, the size of the vacuum window 2 is set to 200*400mm, and 4 or 5 groups of vacuum windows 2 are used as a vacuum group. The space between the two windows of the vacuum group can be a weld or a strip structure remaining after cutting the box body 1. Several vacuum groups are evenly distributed on the outer bottom wall and outer side wall of the box body 1.

[0040] Adaptive changes made according to actual needs are all within the protection scope of this utility model.

[0041] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference numerals in the claims should not be regarded as limiting the claims involved.

[0042] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A vacuum negative pressure sand box, characterized in that: It comprises a box body, the outer wall of which is provided with a vacuum channel, the box body is provided with a plurality of vacuum windows at positions corresponding to the vacuum channel, the inner cavity of the box body is connected with the vacuum channel through the vacuum windows, a plurality of stainless steel bars for intercepting sand molds are provided in the vacuum windows, the plurality of stainless steel bars are arranged in parallel and at intervals, and the vacuum channel is provided with an exhaust nozzle for connecting with a vacuum extraction device.

2. The vacuum negative pressure sand box according to claim 1, characterized in that: Channel steels are buckled on the outer side wall and the outer bottom wall of the box body, and the vacuum channel is formed between the channel steels and the box body.

3. The vacuum negative pressure sand box according to claim 2, characterized in that: A plurality of lifting ears are arranged on the outer side wall of the box body.

4. The vacuum negative pressure sand box according to claim 3, characterized in that: The lifting lug passes through the channel steel and is connected to the box body.

5. The vacuum negative pressure sand box according to claim 3, characterized in that: A reinforcing rib is arranged between the lifting ear and the box body.

6. The vacuum negative pressure sand box according to claim 2, characterized in that: The open end of the channel steel is welded and sealed to the box body.

7. The vacuum negative pressure sand box according to claim 1, characterized in that: A plurality of vacuum extraction windows are evenly distributed on the outer side wall and the outer bottom wall of the box body.

8. The vacuum negative pressure sand box according to claim 1, characterized in that: The stainless steel rod is welded to the vacuum window.

9. The vacuum negative pressure sand box according to claim 1, characterized in that: A reinforcing angle steel is arranged on the bottom edge of the box body.

10. The vacuum negative pressure sand box according to claim 1, characterized in that: A reinforced channel steel is arranged on the top of the box body.

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