JPH03148B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a low pressure casting apparatus.

Normally, a cast product shrinks during the solidification process of the molten metal, resulting in the formation of cavities. Therefore, by providing a riser, the shrinkage of the cast product that occurs during the solidification process is prevented, thereby preventing the formation of cavities. However, providing a feeder increases the amount of molten metal used and requires cutting the feeder, which reduces productivity and is economically problematic. Low-pressure casting is known as a casting method that solves these problems, but since this method uses expensive molds, mold costs increase, making it even more costly for high-mix, low-volume production. It was viewed as a problem.

The present invention aims to solve these problems.

Below, the configuration of the present invention will be explained based on FIGS. 1 and 2. Reference numeral 1 denotes a pedestal supported by the upper ends of a plurality of support frames 2 erected on the upper surface of the foundation, and columns 3 are erected at the four corners of the upper surface of the pedestal 1, and the upper ends of the columns 3 are connected by an upper frame 4. 5 has a molten metal pouring hole 6 at one end, a molten metal replenishing hole 7 at the other end, and a pressure port 8 approximately halfway between the molten metal pouring hole 6 and the molten metal replenishing hole 7. The molten metal container 5 is suspended and supported on the frame 1 via a support member (not shown). Numerals 9 are located on both sides of the molten metal container 1 on the upper surface of the gantry 1 with support members 10 interposed therebetween, at approximately equal intervals.
A mold receiving table consisting of a plurality of support pins slidably inserted into the mold receiving table 9.
The support pin constituting the
A compression spring 11 is interposed between the upper large diameter portion 9a and the support member 10, and is provided to push the mold receiving table 9 upward. On the upper surface of the mold receiving table 9, a pair of completed molds 12 are formed with a mold cavity 12c consisting of a lower mold 12a and an upper mold 12b.
is placed via a surface plate 13 having a through hole 13a in the center, a cover frame 14 (to be described later) is fitted around the outer periphery of the completed mold 12, and a weight 15 is mounted on the top surface.
is loaded. Reference numeral 16 denotes an elevating cylinder attached downward to the upper frame 4, and an elevating frame 17 is fixedly connected to the tip of the piston rod 16a, and the elevating frame 17 is slidably inserted into the support 3 near both ends. , support arms 18 with hooks 18a protruding from the inside of the lower end are hung vertically at a constant interval on the left and right sides, and support members 19 projecting from the middle inside of each support arm 18 have hooks 18a projecting from the inside of the lower end.・Stepped rod 2 with large diameter portions 20a at both lower ends
0 are slidably inserted into each stepped rod 20, and a cover frame 14 with a downwardly expanding tapered surface is suspended from the lower end of each stepped rod 20, and is connected between the support member 19 and the large diameter portion 20a. The compression spring 21 is attached to the cover frame 1.
4 is interposed in such a way that it can be pushed downward. Also, near the center position of the lifting frame 17, there is a weight 1 at the lower end.
A plurality of support rods 22 having large diameter portions 22a at their upper ends are slidably suspended and supported at regular intervals to the left and right through the large diameter portions 22a.
Further, the lower end opening of a bellows-shaped diaphragm 23 equipped with an air supply hole 23a made of a spring steel plate or the like is fixed to the upper surface of the pressure port 8 of the molten metal container 5.
It is connected to the tip of a piston rod 25a of a pressurizing cylinder 25 which is mounted downward via a mounting base 24 on the lower surface, and a two-way switching valve (not shown) is connected to the air supply hole 23a via piping. By the extension of the pressurizing cylinder 25, the diaphragm 23 is bent to increase the pressure of the gas in the airtightly closed upper space of the molten metal in the molten metal container 5, and the molten metal is poured into the mold cavity 12c through the molten metal pouring hole 6.
It is now possible to inject into Reference numeral 26 denotes a guide rail supported by the upper end of a support leg 27 erected from the foundation.
A plurality of guide pins 30 are slidably fitted into the cart 28 at approximately equal intervals in the direction of movement of the cart 28. A bifurcated truck fork 31 is fixedly supported on the upper end of the guide pin 30, and the truck fork 31 is fixedly connected to the tip of a piston rod 32a of a lifter cylinder 32 that is mounted upward on the truck 28. It is designed to move up and down depending on the operation. 33
A support bracket 3 is attached to the bottom surface of the end of the guide rail 26.
The tip of the piston rod 33a is connected to the lower surface of the truck 28 via the cylinder bracket 35, and the traveling cylinder 3 is attached via the cylinder bracket 35.
3, the trolley 28 can be moved along the guide rail 26.

Next, the operation of the device configured as described above will be explained. When the lifting frame 17 is in the raised position, the bogie fork 31 is lowered and retreated, and a certain amount of molten metal is stored in the molten metal container 5, the extending operation of the traveling cylinder 33 moves the bogie 2
8 is moved forward and a surface plate 1 is placed on the upper surface of the truck fork 31.
The completed mold 12 placed through the lifter cylinder 32 is carried directly under the lifting frame 17 and brought to a position where the molten metal injection hole of the mold cavity 12c corresponds to the molten metal pouring hole 6 and stops.
Due to the short circuit operation, the bogie fork 31 descends,
The surface plate 13 on which the completed mold 12 is placed is transferred from the upper surface of the truck fork 31 to the upper surface of the mold receiving table 9. Next, after the carriage 28 and the carriage fork 31 are moved backward by the shortening operation of the travel cylinder 33, the lifting frame 17 is lowered by the extension operation of the lifting cylinder 16, and the weight 15 is loaded on the upper surface of the completed mold 12. When the cover frame 14 is fitted around the outer periphery of the completed mold 12 by the pressing force of the compression spring 21, the completed mold 12 is pushed down against the compression spring 11 and the mold cavity 12 is pushed down.
The molten metal injection hole c is closely connected to the molten metal pouring hole 6. Next, after the two-way switching valve (not shown) connected to the air supply hole 23a is energized and closes the air supply hole 23a, the diaphragm 23 is pressed and bent by the expansion operation of the pressure cylinder 25. The pressure of the gas in the space above the molten metal in the pressure port 8 is increased, and the molten metal in the molten metal container 5 is pressurized and injected into the mold cavity 12c through the molten metal pouring hole 6. After a predetermined period of time has elapsed, when the surface of the molten metal in the mold cavity 12c solidifies, the pressure in the molten metal container 5 is removed by shortening the pressure cylinder 25, and the air supply is stopped by demagnetizing the two-way switching valve. The hole 23a is communicated with the atmosphere, the pressure in the molten metal container 5 is returned to the atmosphere, and the molten metal in the mold cavity 12c is separated from the molten metal in the molten metal container 5.

Next, by the shortening operation of the lifting cylinder 16,
The elevating frame 17 is raised, and the cover frame 14 and the weight 15 are engaged with and supported by the hooks 18 and the like, and are lifted upward and removed from the finished flask 12. Covering frame 14
After the weight 15 is removed, the carriage frame 31 is moved forward together with the carriage 28 by the extension operation of the travel cylinder 33, and is carried below the surface plate 13. Subsequently, by the extension operation of the lifter cylinder 32, the cart fork 31 is raised and the surface plate 13 on which the completed mold 12 is placed is transferred onto the upper surface of the cart fork 31. moves backward and moves together with the cart 28, and the completed mold 12 that has been poured is taken out and demolded. Thereafter, repeat the above operation.

Next, another embodiment of the present invention will be described based on FIGS. 3 and 4. Components having the same configuration in FIG. 1 and FIG. 2 are given the same numbers and their explanations will be omitted. Reference numeral 40 denotes a pair of finished flasks consisting of upper and lower flasks 41 and 42 which have been molded using the vacuum casting molding method (V process) and have been fitted together. A pair of completed molds are built in, and the completed mold flask 40 has suction holes 41a, 41b, 42.
a, 42b, and the casting sand filled in the flasks 41, 42 is sucked through flexible films (not shown) attached to the upper and lower surfaces. It is designed to maintain reduced pressure.

Reference numeral 43 denotes crimping suction devices installed in parallel at predetermined intervals in the upward and downward directions on a support frame 44 erected on the upper surface of the fork truck 31. The crimping suction device 43 includes a cylinder 45 and a piston rod 45.
a crimp suction valve 46 attached to the tip side of a;
Each is composed of The crimp suction valve 46 is internally divided into two chambers, one chamber is connected to a vacuum pump (not shown) via a rubber hose 47, and the tip of the other chamber is open. A communication hole (not shown) is provided in the wall wall partitioning the two chambers, and the communication hole can be opened and closed by a valve member (not shown) fixedly connected to the tip of the piston rod 45a. By the extension operation of the cylinder 45, the crimped suction valve 46,
The opening surfaces of 46 are pressed against the suction holes 41a and 42a, respectively, to open the communication holes and exert a suction action inside each of the flasks 41 and 42. Reference numeral 48 denotes a crimping suction device whose one end is fixedly supported by a support frame 49 that is fixedly supported on the mold receiving table 9 at predetermined intervals in the upward and downward directions, and each crimping suction device 48
has the same structure as the pressure suction device 43, and is removably provided in the suction holes 41b, 42b of the flasks 41, 42 so as to be able to exert a suction action inside the flasks 41, 42.

Note that 50 is a heat retaining device embedded in the molten metal container 5.

The operation of the device configured in this way will be explained. A pair of completed casting flasks 40 with a completed mold held therein by suction by the crimping suction device 43 are placed on the upper surface of the truck fork 31 and moved forward together with the truck 28 by the extension operation of the travel cylinder 33, and are moved forward with the truck 28 directly below the elevating frame 17. When the flask 40 is placed on the upper surface of the bogie fork 31 via the surface plate 13, the completed flask 40 is lowered together with the surface plate 13 and the bogie fork 31, and the finished flask 40 is placed thereon. The placed surface plate 13 is transferred to the upper surface of the mold receiving table 9, and the cart fork 31 temporarily stops midway. The crimping suction devices 48, 48 fixedly supported on the mold receiving table 9 are connected to the suction hole 4.
1b, 42b, and one of the crimping suction devices 43, 43 is attached to the suction holes 41a, 42.
a is disengaged, and then the lifter cylinder 32
Due to the shortening operation, the cart fork 31 is lowered, and the finished flask 40 is transferred from the top surface of the cart fork 31 to the upper surface of the mold receiving table 9 via the surface plate 13. Next, when the weight 15 is lowered and placed on the upper surface of the finished flask 40 by the extension operation of the lifting cylinder 16, the finished flask 40 is lowered together with the surface plate 13 against the compression spring 11, and the mold cavity 40a is lowered.
The molten metal injection hole 40b is connected to the molten metal spouting hole 6, and the pressure of the gas in the space above the molten metal in the pressure port 8 is increased by the expansion operation of the pressurizing cylinder 25, and the molten metal flows through the molten metal spouting hole 6 and the molten metal injection hole. Hole 40b
The liquid is injected into the mold cavity 40a through. When the surface of the molten metal injected into the mold cavity 40a is solidified, the pressure cylinder 25 is shortened.
The pressure in the molten metal container 5 is returned to the atmosphere, and the molten metal in the mold cavity 40a is separated from the molten metal in the molten metal container 5. Next, by the shortening operation of the lifting cylinder 16, the lifting frame 17 and the weight 15 rise upward, and when the weight 15 is removed from the upper mold surface of the completed casting flask 40, the repulsive force of the compression spring 11 causes the weight 15 to move upward. The completed flask 40 is lifted upward. Subsequently, by the extension operation of the traveling cylinder 33, the cart fork 31 is carried directly above the mold receiving table 9, and by the extension operation of the lifter cylinder 32,
When the cart fork 31 rises and comes into contact with the lower surface of the surface plate 13, it temporarily stops midway. Then, one crimping suction device 43, 43 is crimped to the suction hole 41a, 42a, respectively, and the other crimping suction device 48, 48 is disengaged from the suction hole 41b, 42b.

Next, by the extension operation of the lifter cylinder 32 again, the cart fork 31 rises and the completed casting flask 40 is lifted.
is transferred from the mold receiving table 13 to the upper surface of the bogie fork 31, and the completed casting flask 40 is transferred to the top surface of the bogie fork 31 by the shortening operation of the traveling cylinder 33.
1 is placed on the upper surface of the mold via a surface plate 13, taken out to the outside, and demolded. Thereafter, repeat the above operation.

As is clear from the above explanation, according to the present invention, the molten metal poured into the mold cavity is pressurized with uniform pressure, so that a good casting product can be obtained and a riser is not required. It also has the effect of eliminating the need for expensive molds, reducing equipment costs, and being more economically advantageous for high-mix, low-volume production, contributing to this type of industry. The effect is significant.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention, FIG. 2 is a side sectional view of FIG. 1, FIG. 3 is a partially cutaway front view showing another embodiment of the present invention, and FIG. The figure is a side sectional view of FIG. 3. 5: Molten metal container, 6: Molten metal pouring hole, 7: Molten metal supply port, 8: Pressure port, 9: Mold receiving table, 14:
Covering frame, 15: Weight, 17: Lifting frame, 2
3: Diaphragm.

Claims (1)

[Scope of Claims] 1. A molten metal container that retains the temperature of molten metal and injects the molten metal into a mold under pressure by applying pressurized gas to the molten metal; A low-pressure casting device comprising a mold crimping mechanism for crimping the molten metal, the mold crimping mechanism being configured by elastically supporting a plurality of support pins above the molten metal container 5 via compression springs 11 so as to be movable up and down. A mold receiving table 9 is provided, and above the mold receiving table 9 is provided an elevating frame 17 that can be raised and lowered by a cylinder 16, and the elevating frame 17 is provided with a support rod that is vertically slidable and supported by suspension. 1. A low-pressure casting apparatus characterized in that a weight 15 is suspended via a weight 22. 2. A molten metal container that keeps the molten metal warm and injects the molten metal into the mold under pressure by applying pressurized gas to the molten metal, and a mold crimping mechanism that presses the molten metal injection hole of the mold to the molten metal spout hole of the molten metal container. A low-pressure mold casting apparatus consisting of: the mold crimping mechanism includes a mold receiving table 9 configured by elastically supporting a plurality of support pins via compression springs 11 so as to be movable up and down above the molten metal container 5; An elevating frame 17 is provided above the mold receiving table 9 and is movable up and down by a cylinder 16, and a weight is attached to the elevating frame 17 via a support rod 22 which is vertically slidable and supported by suspension. A support arm 18 on which a weight 15 is suspended and a lower inner hook 18a protruding from the lifting frame 17 is provided.
are installed vertically at a constant interval on the left and right, and the support arm 1
8. A low-pressure casting apparatus characterized in that a support member 19 is provided in the middle of the support member 8, and a cover frame 14 is movable up and down and elastically suspended from the support member 19.