JP2920813B2 - Metal frame for casting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a box-shaped casting metal frame constituting a casting frame into which sand is poured for a casting operation.

[0002]

2. Description of the Related Art As a box-shaped casting metal frame of this kind, there is known one in which a plurality of metal frames are sequentially conveyed along a casting line. Then, while the metal frame is transported along the casting line, molding by sanding, casting, cooling, and removal of the product are performed. The metal frame after the product is taken out is returned to the starting end of the casting line again.

[0003] As for the molding work in the metal frame, a so-called self-weight type in which sand is solidified by its own weight while applying vibration to the metal frame has been mainly used. In this self-weighting metal frame, a large number of gas holes are formed on the entire circumference of the frame, and gas generated during casting is discharged outside the frame.

In recent years, a so-called vacuum system of a suction type has been proposed as a precision molding system. This is to arrange a plurality of suction pipes in a metal frame to introduce a negative pressure into the metal frame, and to try to harden sand by the action of the negative pressure. According to the vacuum method, since the sand is satisfactorily compacted in the frame, there is an advantage that the accuracy of the thickness and the shape of a product such as a cast iron pipe can be improved. Further, since the gas can be forcibly degassed by the action of the negative pressure, the quality of the product can be improved from that point as well.

[0005]

However, in the conventional vacuum system, since a function is not exhibited when gas holes such as a self-weight type are present, a metal frame completely different from the self-weight type is newly provided. There is a problem that must be manufactured. Further, since several suction conduits are arranged inside the metal frame, there is a problem that work such as work for putting a casting model in the metal frame easily occurs, and workability is poor.

Accordingly, an object of the present invention is to solve such a problem and to provide a vacuum-type casting metal frame which can be used as a conventional self-weighting type and has excellent workability.

[0007]

In order to achieve the above object, the present invention comprises a plurality of gas holes formed through a frame wall;
A gas passage provided around the frame wall and communicating with the gas hole, a connecting member for connecting the gas passage to a negative pressure source, and closing when the gas passage becomes a negative pressure; A check valve that opens when the inside of the passage becomes pressurized and releases the gas pressure to the atmosphere side.

[0008]

According to such a configuration, the inside of the metal frame is communicated with the negative pressure source through the connecting member, the gas passage, and the gas hole, so that a negative pressure is introduced into the metal frame and the vacuum type A casting frame is formed. At this time, since there is no suction conduit in the metal frame, problems such as trouble in the operation of putting the model in the metal frame are avoided.

In addition, a vacuum-type metal frame is constructed by slightly remodeling a conventional weight-type metal frame. In addition, since it has a check valve for degassing, it can be used as a self-weight type with good workability, and one metal frame can be used for both the self-weight type and the vacuum type. The non-return valve is also used as a safety measure for venting gas when a negative pressure source fails when used as a vacuum type.

[0010] By connecting the gas passage to the negative pressure source via one connecting member, suction from the entire circumference of the metal frame becomes possible.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 to 6, reference numeral 11 denotes a metal frame constituting a casting frame, which is formed in a rectangular box with a bottom and an open upper end. 12 is a peripheral frame wall, 13 is a bottom plate, and 14 is an opening at an upper end. A predetermined casting line is formed by sequentially arranging a plurality of such metal frames 11, and at both ends of the metal frame 11, contact blocks 15 between adjacent metal frames 11 are provided. . These contact blocks 15 can adjust the movement in the horizontal direction from the metal frame 11, and are configured so that the total length of the metal frame 11 can be set to a specified value. As a result, the plurality of metal frames 11 can be sequentially advanced at a constant pitch.

A hook 16 and a support pin 17 for tilting the metal frame 11 to remove products and sand from the metal frame 11 after casting and cooling work are provided on the front and rear surfaces of the metal frame 11.
Are provided. At the bottom of the metal frame 11, a slide plate 18 is provided for sequentially feeding the metal frame 11 on a transport path. At both ends of the metal frame 11, hooks 19 for suspending and supporting the metal frame 11 are provided, and by supporting the metal frame 11, the metal frame 11 can be loaded into the transport path or unloaded from the transport path. It is possible to do.

In the entire periphery of the frame wall 12 of the metal frame 11, a four-stage closed gas passage 20 composed of a channel material is provided.
Is provided. A reinforcing member 21 for reinforcing the opening 14 is provided on the entire periphery of the upper edge of the frame wall 12. The reinforcing member 21 is also made of the same channel material. The upper and lower channel members forming the gas passage 20 and the reinforcing member 21 are connected to each other by a vertical channel member 22. This channel material 22 is
, Ie, at the four corners of the metal frame 11 and at the center of each frame wall 12.

In the channel material constituting the gas passage 20, an opening is provided at a portion corresponding to the channel material 22 in the vertical direction.
23 are formed, and the vertically adjacent gas passages 20 communicate with each other. As a result, all the gas passages 20 in the upper and lower four stages are connected to each other by the communication passage 24 formed by each channel material 22. In portions where this communication is not necessary, that is, between the uppermost gas passage 20 and the reinforcing member 21 and between the lowermost gas passage 20 and the bottom plate 13, the vertical channel member 22 is merely a reinforcing member. Function. Of course, the channel material constituting the gas passage 20 and the channel material constituting the vertical communication passage 24
22 also has the function of reinforcing the metal frame 11.

As shown in FIGS. 3, 7, and 8, the inner peripheral surface of the frame wall 12 corresponding to the gas passage 20 and the frame wall corresponding to the communication passage 24 are provided.
A belt-like thick member 25 is attached to the inner surface of the substrate 12 in close contact. A gas hole 26 is formed through the frame wall 12 and the thick member 25. This gas hole 26
The portion of the thick member 25 is formed to have a larger diameter than the portion of the frame wall 12.

As shown in FIG. 7 and FIG.
A vent hole member 27 is press-fitted into the portion of the gas hole 26 in. The vent hole member 27 is formed in a cap shape having a minute ventilation hole 29 penetrating the end face 28, and since the diameter of the gas hole 26 is smaller in the frame wall 12 than in the thick member 25, It is positioned against the frame wall 12. By arranging the vent hole member 27 in this way,
Sand filled in the metal frame 11 is prevented from entering the gas passage 20 and the communication passage 24.

As shown, the tip of the vent hole member 27 slightly protrudes from the thick member 25 toward the inside of the metal frame 11. On the rear side of the metal frame 11, the upper two of the four upper and lower stages are press-fitted in a direction in which the end face 28 is on the back side as shown in FIG. this is,
If the end face 28 is on the front side as shown in FIG. 7, when the product is taken out through the opening 14 of the metal frame 11, the product hits the end face 28, and the vent hole 29 may be crushed and closed. On the other hand, the lower two stages are press-fitted with the end face 28 as the near side as shown in FIG. This is because when the product is taken out through the opening 14 of the metal frame 11 as described above, the product is less likely to collide, so that it is not necessary to consider the collapse of the vent hole 29 and the vent hole member 27 This is to prevent sand from accumulating inside.

As shown in FIGS. 1 to 6, on one end face of the metal frame 11, an on-off valve 31 communicating with a gas passage is provided. As shown in FIG. 9, the on-off valve 31 is constituted by a ball valve or the like, and can be opened and closed by manually operating a handle 32.
And a communication port 34 to the negative pressure source at the other end. Connection port 34
Is opened on the front side of the metal frame 11 serving as the working side, and is arranged so that the front end edge thereof is located slightly deeper than the front of the metal frame 11, and is located outside the metal frame 11. It is configured so as not to protrude in the direction. This prevents collision with another device or the like.

As shown in FIG. 10, a support box 36 is provided at a position above the on-off valve 31 so as to be isolated from the gas passage 20. A valve 37 is mounted. The small on-off valve 37 can be opened and closed by manually operating a handle 38 in the same manner, and is connected to the support box 36 by a vent 39 and a socket 40. The on-off valve 37 is also provided at a position slightly recessed from the front of the metal frame 11. By using the on-off valve 37, it is possible to confirm whether or not a negative pressure is generated in the metal frame as described later.

A check valve 41 is mounted at an appropriate position on the outer surface of the web of the channel material constituting the gas passage 20. In detail, as also shown in FIGS. 11 and 12,
A through hole 42 is formed in the channel material web, and a mounting sleeve communicating with the through hole 42 is formed on an outer surface of the web.
43 are welded. An opening / closing lid 45 is supported by a band 44 fixed to the outer periphery of the sleeve 43 so as to be openable and closable.

The opening / closing lid 45 is closed by its own weight and opened by the internal pressure of the gas passage 20. Opening / closing lid 45
A packing 46 made of soft rubber or the like is provided on the inner surface of the. The packing 46 is configured such that when no negative pressure is acting on the gas passage 20, a slight gap 47 is formed between the packing 46 and the end face of the sleeve 43. This gap 47
When a negative pressure acts on the gas passage 20, it is closed by the elastic deformation of the packing 46 so that a complete sealing state is obtained.

As shown in FIGS. 11 and 12, the check valve 41 can be installed at any position in the height direction of the web of the channel material constituting the gas passage 20 if necessary. . In addition, the check valve 41 is not provided on the front side of the metal frame 11 on the working side for safety.

When the metal frame 11 having such a configuration is used in a vacuum system and applied to, for example, a full molding method, a casting sand is charged after a model is put in the metal frame 11. At this time, since there is no suction conduit or the like in the metal frame 11, the operation of inserting the model can be easily performed. Then, the connection port 34 of the on-off valve 31 is connected to a negative pressure source, and the on-off valve 31 is opened. Then, the check valve 41 is completely closed due to the elastic deformation of the packing 46, and the air in the frame is sucked through the gas holes 26 around the entire circumference of the metal frame 11 to generate a negative pressure, thereby causing a casting. The sand is sufficiently compacted and the sand filling is completed. At this time, an air hose equipped with a pressure measuring device is connected to the on-off valve 37, and the suction pressure is measured and recorded, so that it is confirmed whether or not a negative pressure is generated during suction.

Therefore, the molten metal is cast while maintaining the state where the negative pressure is introduced into the metal frame 11. At this time, gas is generated, and the generated gas is subjected to the action of the negative pressure introduced as described above, and the vent hole 29 of the vent hole member 27 is formed.
After passing through the gas holes 26 and the gas passages 20 communicating with each other, they are combined into one, and then discharged outside the metal frame 11 through the on-off valve 31. Therefore, only by connecting the negative pressure source to one connection port 34, gas can be exhausted over the entire metal frame 11.

At this time, gas holes are formed all around the metal frame 11.
26 are formed, and the gas holes 26 are formed over the upper and lower four stages corresponding to the buried portion of the model in the sand, so that the gas generated around the model is uniformly distributed to the gas holes 26. Guided and discharged. At this time, suction is confirmed by pressure measurement using the above-described on-off valve 37. In this case, if a suction device or the like constituting a negative pressure source fails, the negative pressure is stored in the gas passage 20. Is not introduced, and gas cannot be discharged through the on-off valve 31. However, in such a case, the check pressure
The opening / closing lid 45 of the 41 opens, and gas is discharged through the check valve 41. If the gas pressure is not high enough to open the opening / closing lid 45, the gas is discharged through the gap 47 between the packing 46 of the check valve 41 and the end face of the sleeve 43. Gas is discharged.

After several minutes from the end of the casting, the introduction of the negative pressure into the metal frame 11 is stopped by closing the on-off valve 31. Then, when the product is solidified by cooling, the metal frame 11 is tilted to the back side to take out the product and sand inside.

When the metal frame 11 is used as a self-weight type, the on-off valve 37 is closed, and the connection of the negative pressure source to the on-off valve 31 is not performed. In this case, gas is discharged through the check valve 41.

As described above, there is an advantage that the same metal frame 11 can be used for both the vacuum type and the self-weight type. In addition, the metal frame 11 can be configured by only slightly modifying the conventional weight-type metal frame, and therefore, a casting operation using a vacuum method can be performed using a casting line for the conventional weight-type metal frame. .

[0029]

As described above, according to the present invention, since the inside of the metal frame can be communicated with the negative pressure source through the connecting member, the gas passage, and the gas hole, a negative pressure is introduced into the metal frame. A vacuum-type casting metal frame can be configured, and at this time, since there is no suction conduit in the metal frame, problems such as trouble in work for putting a model in the metal frame occur. Can be avoided. In addition, a vacuum type metal frame can be configured by slightly modifying the conventional self-weight metal frame, and since it has a check valve for degassing, it can be used as a self-weight type with good workability. One metal frame can be used for both the self-weight type and the vacuum type. The check valve can also be used as a safety measure for venting when a negative pressure source fails when used as a vacuum type. Further, since the gas passage is connected to the negative pressure source via the connection member, suction from the entire circumference of the metal frame can be performed with only one suction connection port per metal frame.

[Brief description of the drawings]

FIG. 1 is a front view of a casting metal frame according to an embodiment of the present invention.

FIG. 2 is a plan view of the metal frame.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a right side view of the gold frame.

FIG. 5 is a left side view of the gold frame.

FIG. 6 is a rear view of the same metal frame.

FIG. 7 is an enlarged view showing an arrangement of a lower vent hole member in the metal frame.

FIG. 8 is an enlarged view showing an arrangement of an upper vent hole member in the metal frame.

FIG. 9 is an enlarged view showing the on-off valve and its periphery in the same metal frame.

FIG. 10 is an enlarged view showing another on-off valve and its periphery in the same metal frame.

FIG. 11 is an enlarged sectional view showing a check valve in the metal frame.

FIG. 12 is a cross-sectional view showing another check valve in the metal frame in an enlarged manner.

[Explanation of symbols]

 12 Frame wall 20 Gas passage 26 Gas hole 31 On-off valve 41 Check valve

Claims (1)

(57) [Claims] 1. A box-shaped casting metal frame which forms a casting frame in which sand is filled for a casting operation, comprising: a plurality of gas holes formed through the frame wall; A gas passage provided around and communicating with the gas hole, a connecting member for connecting the gas passage to a negative pressure source, and the gas passage having a negative pressure.
Closes when the pressure reaches
And a check valve for opening the gas pressure to the atmosphere side when opened .