JPH1133672A - Constant quantity feeding device for molding sand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly weigh the feeding quantity of the molding sand to be fed in a tank by one weighing apparatus. SOLUTION: A device for feeding the molding sand of the prescribed quantity, is provided with a molding sand feed tank 20 which is suspended from a truck 4 between a molding sand feeding position A and the molding sand discharging position B in a reciprocal manner. A guide rail 5 to guide the truck 4 between the positions is divided into a rail body 5A on the molding sand feeding position side and a rail body 5B on the molding sand discharging position side, and a free end part of the rail body 5A is vertically movable with and end part side of the rail body 5A of the molding sand feeding position side opposite to the rail body 5B on the molding sand discharging position side as a pivotably attached part 9, and a free end part of the rail body 5A on the molding sand feeding position side is supported by a weighing apparatus 10 to weigh the load to be applied to the rail body 5A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting apparatus for producing a molding core or the like by heating and molding a mold sand into a required shape, and to an apparatus for quantitatively supplying the mold sand into a mold.

[0002]

2. Description of the Related Art Conventionally, when manufacturing a casting core,
At the mold sand supply position, mold sand is supplied from the mold sand supply hopper into the mold sand tank for a predetermined time, and then the mold sand tank is moved to a position immediately above the mold of the mold sand discharger, and thereafter, the mold sand tank is provided by the crimping cylinder provided at the mold sand discharge position. The mold sand in the mold sand tank is then forced into the mold by introducing blast air into the mold sand tank, and the mold sand in the mold sand tank is forcibly supplied into the mold. Was manufacturing cores.

However, in the above manufacturing apparatus, since the molding sand is supplied by the timer control, when the flow of the molding sand is poor, a predetermined amount of the molding sand is not supplied into the molding sand tank. In a good case, the supply amount of the mold sand is likely to vary, for example, the mold sand is supplied into the mold sand tank in an amount larger than a predetermined amount, and it is difficult to keep the supply amount of the mold sand constant.

[0004] In order to solve the above-mentioned problems, there has been proposed a mold sand quantitative supply apparatus in which mold sand is supplied by so-called weight control so that the supply amount of mold sand into the mold sand tank does not vary. Japanese Utility Model Laid-Open No. 2-14829 and the like). According to this, there is no variation due to the properties of the mold sand, and the supply amount of the mold sand supplied into the tank can be accurately weighed.

[0005]

However, according to the apparatus for quantitatively supplying mold sand described above, a weigher is installed below the mold sand supply position, and weighing is performed with the mold sand tank placed on the weigher. Therefore, it is usually necessary to provide a plurality of weighers. If one weigher is provided, the placement of the mold sand tank on the weigher becomes unstable, and a weighing error easily occurs. In addition, the conventional mold sand metering and feeding apparatus has a problem that the structure is complicated and the manufacturing cost is high.

The present invention has been made in view of the above-mentioned problems, and provides an apparatus for quantitatively supplying mold sand for casting which can accurately measure the amount of mold sand supplied into a tank by a single weigher. The purpose is. It is another object of the present invention to provide a casting mold sand metering and feeding device having a simpler structure than a conventional device.

[0007]

The invention according to claim 1 is
As shown in FIG. 1, in a casting sand supply device including a mold sand supply tank 20 which is suspended between a mold sand supply position A and a mold sand discharge position B and is reciprocally movable, as shown in FIG. Is divided into a mold sand supply position side rail body 5A and a mold sand discharge position side rail body 5B, and the mold sand supply position side rail body 5A is separated from the mold sand discharge position side rail body 5B. A free end of the rail main body 5A is provided so that the free end of the rail main body 5A can move up and down as a pivotal attachment portion 9 at the opposite end of the rail main body 5A. Is supported by a weighing device 10 for weighing the weight.

A second aspect of the present invention is the constant volume feeder for mold sand for casting according to the first aspect, wherein the rail body 5A on the mold sand supply position side.
As shown in FIG. 7, the pivoting portion 9 of the ball bearing 1
1 and a pivot shaft 12 supported thereon.

According to a third aspect of the present invention, in the casting mold sand metering and feeding apparatus according to the first or second aspect, as shown in FIGS. 6 and 8, the guide rail 5 has a pair of both sides of the mold sand supply position side rail body 5A, 5A and a pair of mold sand discharge position side rail bodies 5B, 5B on both sides, and the both mold sand supply position side rail bodies 5A, 5A
A and 5A are supported by idle balls 13 protruding from both side surfaces of the horizontal beam 3 extending parallel to the inner side surfaces of the horizontal beam member 3 so as to restrict the displacement in the rail width direction. It is characterized by.

In a fourth aspect of the present invention, as shown in FIGS. 5 and 6, the free ends of the pair of rail bodies 5A, 5A are connected to each other. A support rod 17 projects upward from a middle portion of the connecting rod 16 in the longitudinal direction, and the support rod 17 is supported by the weighing device 10 installed at a fixed position.

According to a fifth aspect of the present invention, in the apparatus for supplying a fixed amount of sand for casting mold according to any one of the first to fourth aspects, a bogie driving means for reciprocating the bogie along the guide rail.
1 and 9, as shown in FIGS. 1 and 9, is composed of a fluid pressure cylinder interposed between the support frame 1 below the mold sand supply position A and the truck 4, and the tip of the piston rod 23b of the cylinder is Are pivotally connected to each other by a ball joint 25.

According to a sixth aspect of the present invention, in the casting mold sand metering and feeding apparatus according to any one of the first to fifth aspects, the mold sand supply tank 20 is formed by a plurality of coil springs 21 as shown in FIGS. It is characterized in that it is hung on a cart 4.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic side view of a mold sand metering and feeding apparatus according to the present invention, FIG. 2 is a partially sectional side view of the apparatus at a mold sand feeding position, and FIG. FIG. 4 is a partial cross-sectional front view of the device at a mold sand supply position A, FIG. 5 is a rear view of the device at a mold sand supply position A, and FIG. FIG. As you can see from these figures,
A pair of support frames 1, 1 on both sides are erected at the mold sand supply position A, and the mold 2 at the mold sand discharge position B from the upper ends of both support frames 1, 1.
A horizontal beam 3 extends over the position directly above, and at the lower end of the horizontal beam 3, a guide rail 5 for guiding the carriage 4 between a mold sand supply position A and a mold sand discharge position B is provided on the horizontal beam 3. This guide rail 5 is provided over the entire length.
The carriage 4 is suspended by horizontal guide rollers 6a and 6b via upper and lower guide rollers 6a and 6b.

As can be seen from FIGS. 4 and 5, the horizontal beam member 3 is formed in a downward U-shape in cross section by a pair of side plates 3a, 3a on both sides and an upper plate 3b connecting the upper ends of both side plates 3a, 3a. The pair of connecting members 7, 7 provided on the side of the mold sand supply position A are connected and fixed to the support frames 1, 1. As can be seen from FIGS. 3 and 4, the cart 4 is formed in an upward U-shaped frame by a pair of side frames 4a, 4a on both sides and a lower frame 4b connecting lower ends of the both frames 4a, 4a. Upper and lower guide rollers 6a and 6b are axially mounted at two places before and after 4a, and a circular opening 4c is provided at the center of the lower frame 4b.

The guide rail 5 is divided into a rail body 5A on the side of the mold sand supply position and a rail body 5B on the side of the mold sand discharge position.
Is fixed to the horizontal beam member 3 with bolts 8, and the mold sand supply position side rail body 5 </ b> A has a free end portion of the rail body 5 </ b> A at the end facing the mold sand discharge position side rail body 5 </ b> B. The free end portion of the rail body 5A on the side of the mold sand supply position is supported by a weighing device 10 that weighs a load applied to the rail body. In addition, these mold sand supply position side rail body 5A
In addition, the pair of rail bodies 5B on the side of the mold sand discharge position are disposed along the lower end portions on both sides of both side plates 3a of the horizontal beam member 3 having a U-shaped cross section. The weigher 10 is
It consists of a strain gauge type weight sensor (load cell).

As shown in FIGS. 6 and 7, the pivoting portion 9 of each of the mold sand supply position side rail main bodies 5A is mounted on a ball bearing 11 and each side plate 3a of the horizontal beam 3 which is supported and supported by the ball bearing. Even when a considerable load is applied to the rail body 5A on the side of the mold sand supply position, the pivot portion 9 is smoothly pivoted with little resistance received by the load, because it is formed by the fixed pivot shaft 12 fixed thereto. Therefore, the free end side of the rail body 5A can be moved up and down very finely, and the weighing device 10 can weigh more accurately. As can be seen from FIGS. 6 and 8, a pair of mold sand supply position side rail bodies 5A, 5A on both sides are provided.
Are both side plates 3a of the horizontal beam member 3 having a U-shaped cross section which extend parallel to and close to the inner surfaces of the rail bodies 5A, 5A, respectively.
The ball 3a is supported in a point contact state by idle balls 13 protruding outwardly from the base 3a, so that displacement in the rail width direction is restricted. Each idle ball 13 is rotatably held at the tip of a ball receiving member 14 attached to the side plate 3a as shown in FIG. Further, as shown in FIG. 6, a support roller 15 for supporting the outer surface of the rail main body 5A on each side of the mold sand supply position is mounted on the carriage 4 side.

Also, as shown in FIGS. 1 to 3, 5 and 6, a pair of mold sand supply position side rail bodies 5A, 5A on both sides are provided.
Are connected to each other by a connecting rod 16.
A support rod 17 projects upward at the center of the longitudinal direction of the horizontal beam 6, while a horizontal member 18 is attached to an end of the horizontal beam 3, and the weighing device 10 is attached to the horizontal member 18 via a bracket 19.
Is attached to the weighing device 10, and the support rod 17 is attached to the weighing device 10.
Is supported. In this manner, the free ends of the rail main bodies 5A, 5A on both sides of the sand supply position are stably supported by the weigher 10 via the support rod 17 at the center position in the rail width direction. Weighting can be performed more accurately.

Below the carriage 4, a mold sand supply tank 20 is provided.
The mold sand supply tank 20 is suspended on the carriage 4 by four coil springs 21. As shown in FIGS. 2 and 3, the mold sand supply tank 20 has a substantially rectangular parallelepiped tank main body 20a and an upper cylindrical body 20b which is erected at the upper center of the tank main body 20a and communicates with the inside of the tank main body 20a. And a peripheral frame 22 is attached to the upper part of the tank body 20a. The four coil springs 21 are interposed between the peripheral frame 22 and the lower frame 4b of the carriage 4, and an upper cylindrical body The upper end of 20 b protrudes into the carriage 4.

A bogie driving means 23 for reciprocating the bogie 4 along the guide rails 5 includes a fluid pressure cylinder such as an air cylinder interposed between the support frame 1 below the mold sand supply position A and the bogie 4. The cylinder body (cylinder tube) 23a side is pivotally connected to the support frame 1 via a pivoting portion 24, and the tip of the piston rod 23b is trolleyed by a ball joint (also called a free joint) 25. 4 is pivotally connected. This piston rod 23b
2, 4 and 9 for the connection between
As shown in the figure, a bracket 26 is attached to the lower frame 4b of the carriage 4, and a ball joint 2 is provided between a mounting bolt member 27 fixed to the bracket 26 and the tip of the piston rod 23b.
5, the tip end of the piston rod 23b is pivotally connected to the carriage 4 so as to be bent and displaceable.
By connecting the piston rod 23b to the trolley 4 side by using, the vertical displacement of the trolley 4 accompanying the vertical displacement of the rail body 5A on the side of the mold sand supply position when the weighing apparatus 10 weighs the mold sand supply tank 20 is restrained. And therefore a very accurate weighing can be performed.

Further, as shown in FIG. 1, a mold sand supply position A on the horizontal beam 3
And a high-pressure air supply device 30 for supplying high-pressure air into the mold-sand supply tank 20 is provided at a mold-sand discharging position B on the horizontal beam 3. It is.

The tank body 20 of the mold sand supply tank 20
As shown in FIG. 2 to FIG. 4A, the lower part of the inner side surface is formed on a mortar-shaped inclined surface 31, and the upper cylindrical body 20b
Is inserted into a circular opening 4c provided in the lower frame 4b of the carriage 4 and protrudes into an upper portion thereof. At the center of the bottom cover 32 that closes the bottom opening of the tank body 20a, the tank body 2
In the blow plate 34 provided on the lower surface of the bottom lid 32, a slot 33 is formed in the longitudinal direction of the bottom cover 32 so as to correspond to the mold sand inlet 35 of the mold 2 (see FIGS. 10 and 11). Slot 3
An outlet 36 communicating with the mold sand supply tank 2 is provided.
When high-pressure air is injected into the mold 0, the mold sand 28 in the tank 13 is forcibly discharged from the outlets 36 into the mold 2 by the injected air. 2 to 4, reference numeral 37 denotes a bottom cover 3 in the tank body 20a.
A mold sand support plate that covers the long hole 33 in the vicinity of 2 so that the weight of the mold sand 28 in the mold sand supply tank 20 does not fall on the long hole 33 so that the mold sand 28 does not flow naturally from the long hole 33 and the outlet 36. It is for.

As shown in FIGS. 3 and 4, the mold sand supply device 29 includes a mold sand supply hopper 39 and a mold sand extending downward from the hopper 39 and penetrating through the upper plate 3 b of the horizontal beam 3. The supply cylinder 40 is disposed so as to face the lower end opening of the supply cylinder 40, and both side edges thereof are inserted into guide grooves provided in both of the mounting plates 38, 38 so as to be horizontally movable, and have a central portion. A rectangular plate-shaped opening / closing damper 43 having a mold sand supply hole 42 formed therein, a damper driving device 44 composed of a fluid pressure cylinder such as an air cylinder for horizontally moving the opening / closing damper 43, and are mounted on the opening / closing damper 43. And a mold sand leakage prevention cylinder 46 which is loosely fitted to the lower end of the mold sand supply cylinder 40 and has a mold sand supply nozzle 45 penetrating the bottom plate thereof. When the opening / closing damper 43 is horizontally moved by the damper driving device 44 from the state where the 45 is closed, the mold sand supply hole 42 of the opening / closing damper 43 matches the mold sand supply nozzle 45 as shown in FIGS. 3 and 4. The mold sand 28 in the hopper 39 is supplied to the mold sand supply tank 20 via the mold sand supply cylinder 40, the mold sand supply nozzle 45, and the mold sand supply hole 42. In FIGS. 2 and 3, reference numeral 47 denotes a manual opening / closing damper appropriately provided above the mold sand supply cylinder 40.

As shown in FIGS. 10 and 11, the high-pressure air supply device 16 penetrates through the upper plate 3b of the horizontal beam member 3 and is connected to a fluid pressure cylinder such as an air cylinder fixed to the upper plate 3b. And an air supply unit 50 formed by extending a cylinder tube of the cylinder upward, and penetrates a piston 51 of the cylinder, is integrally fixed to the piston 51, and the upper end thereof is Air supply cylinder 5 fitted in air supply unit 50
2 and fixed to the lower end of the air supply cylinder 52,
When the piston 51 of the cylinder is lowered most, FIG.
As shown in FIG. 1, a trumpet-shaped blow flange 53 which is press-fitted to an upper end opening of a mold sand supply tank 20, and a three-way switching valve disposed at an upper end of the air supply unit 50 and connected to an air supply source. 54, the crimping drive 49
The air supply cylinder 52 is lowered by the
Is pressed against the upper end opening of the mold sand supply tank 20, and then the three-way switching valve 54 is switched to supply high-pressure air from the air source into the mold sand supply tank 20 via the air supply cylinder 52, whereby the mold sand supply tank 20 Is forcibly discharged into the mold 2 from each outlet 36. In FIGS. 10 and 11, reference numeral 55 denotes a sandproof filter, and reference numerals 56 and 57 denote air ports.

A method for supplying the mold sand 28 by the casting mold sand quantitative supply apparatus having the above-described configuration will be described. First, as shown by the solid line in FIG. 1, a truck 4 in which an empty mold sand supply tank 20 is suspended by a coil spring 21 at a mold sand supply position A is supported on a rail body 5A of the guide rail 5 on the mold sand supply position side. In this state, the load applied to the rail body 5A on the side of the mold sand supply position is weighed by the weigher 10. As described above, the mold sand supply position side rail main body 5A has the end facing the mold sand discharge position side rail main body 5B pivotally attached to the horizontal beam 3 by the pivoting portion 9, and its free end is vertically moved. The load applied to the rail main body 5A is weighed by the weighing device 10 which is movable and supports the free end of the rail main body 5A. In this case, the weight other than the mold sand supply tank 20, that is, the weight of the support rod 17, the rail body 5 </ b> A on the mold sand supply position side having one end pivotally attached thereto, the bogie 4, and the like are also loaded on the weighing machine 10. In addition, by connecting the piston rod 23b to the truck 4 side by using the ball joint 25, the vertical displacement of the truck 4 accompanying the vertical displacement of the mold body supply position side rail body 5A at the time of weighing by the weighing device 10 is restrained. And therefore a very accurate weighing can be performed.

Next, it is detected from the output signal from the weigher 10 that the weight is loaded on the weigher 10,
The damper driving device 44 is operated by the detection signal,
The open / close damper 43 is moved to the open position. As a result, as shown in FIGS. 3 and 4, the mold sand supply hole 43 of the opening / closing damper 43 communicates with the mold sand supply nozzle 45 of the mold sand leakage prevention cylinder 46, and the mold sand 28 in the hopper 39 is removed from the mold sand supply tank 2.
It is supplied within 0. Then, the supplied weight is weigher 1
When the measured value matches the set value, the opening / closing damper 43 is moved to the closing position by the damper driving device 44 by the detection signal, and the mold sand supply nozzle 45 is closed.

In this case, since the supply amount of the mold sand 28 to be supplied into the mold sand supply tank 20 is adjusted by weight control, it is necessary to accurately weigh the mold sand 28 regardless of the flow of the mold sand 28. Can be. If there is a possibility that excess mold sand 28 may be supplied into the tank 20 due to a time lag from the time when the detection signal is transmitted from the weighing device 10 to the time when the mold sand is completely stopped, for example, the required amount of mold sand is 10 kg.
If the surplus molding sand amount is 500 g, the set value may be set to 9.5 kg, whereby the required amount of molding sand 28 of 9.5 kg + 500 g = 10 kg is supplied into the tank 20.

After the mold sand 28 having a predetermined weight is supplied into the mold sand supply tank 20 as described above, the bogie driving means 23
Thus, the carriage 7 is horizontally moved along the guide rail 5 from the mold sand supply position A to the mold sand discharge position B as shown by the phantom line in FIG. During this movement, the carriage 4 is transferred from the mold body supply position side rail body 5A to the mold sand discharge position side rail body 5B at the same level as the rail body 5A.

Thereafter, the blow flange 53 is pressed against the upper end opening of the mold sand supply tank 20 by lowering the air supply cylinder 52 as shown in FIG.
To make the outlet 36 at the bottom of the tank body 20a coincide with the mold sand inlet 35 of the mold 2. When the three-way switching valve 54 is switched and high-pressure air is pressed into the mold sand supply tank 20 from the air supply source, the mold sand 28 in the tank 20 is blown out of the mold 2 by the press-in air.
It is forcibly discharged inside.

After the completion of the mold sand discharge, the three-way switching valve 54 is switched so that the inside of the mold sand supply tank 20 is communicated with the atmosphere to release the air. In this case, since the upper end of the mold sand supply tank 20 is closed by the sandproof filter 55, the mold sand 28 in the mold sand supply tank 20 is not scattered to the outside. afterwards,
The air supply cylinder 53 is raised by the pressure bonding drive 49, and the carriage 4 and the mold sand supply tank 20 are returned to the mold sand supply position A by the carriage drive means 23. Thereafter, the above-described operation is repeated.

[0030]

According to the first aspect of the present invention, the guide rail which guides the carriage between the mold sand supply position and the mold sand discharge position is divided into a mold sand supply position side rail body and a mold sand discharge position rail body. The mold sand supply position side rail body is provided so that the free end of the rail body can be moved up and down with the opposite end side to the mold sand discharge position side rail body as a pivotal connection, and the free end of the mold sand supply position side rail body. Since the portion is supported by a weigher that weighs the load applied to the rail body, it is possible to use only one weigher without providing a plurality of weighers as in the conventional device. The amount of the mold sand supplied into the mold sand supply tank can be accurately and weighed as quickly as possible.

According to the second aspect, the pivot portion of the rail body on the side of the mold sand supply position is formed by the ball bearing and the pivot shaft supported by the ball bearing. , The pivoting portion is less affected by the load and can smoothly pivot, so that the free end side of the rail body can be moved up and down very finely, It is possible to more accurately measure the amount of mold sand supplied by the weigher.

According to the third aspect, the guide rail is composed of a pair of mold sand discharging position side rail bodies on both sides, and a pair of mold sand supply position side rail bodies on both sides. Because both types of sand supply position are supported by idle balls protruding from both sides of a horizontal beam material extending parallel to and near the inner surface of the rail main body on the side of the rail, displacement in the rail width direction is restricted. When the bogie is positioned on the rail body on the side of the mold sand supply position, the rail body on the side of the mold sand supply side does not roll and rattle, and the weight of the mold sand supply by the weigher is more stable and more accurate. Can be done.

According to the fourth aspect, a supporting rod is provided to project upward at an intermediate portion in a longitudinal direction of a connecting rod connecting the free ends of the pair of mold sand supply position side rail bodies, and the supporting rod is installed at a fixed position. Because the weighing device is supported, the free end of the rail body on the side of the mold sand supply position is supported by the weigher in a stable state, and the weighing of the amount of mold sand supply can be performed more accurately.

According to the fifth aspect, the carriage driving means comprises a fluid pressure cylinder interposed between the support frame and the carriage below the mold sand supply position, and the tip end of the piston rod of the cylinder is provided with a ball relative to the carriage. Since the joints are pivotally connected by the joint, the vertical movement of the bogie due to the vertical movement of the rail body at the mold sand supply position side is not restrained when the mold sand supply amount is weighed by the weighing device, and therefore, extremely accurate weighing is performed. It can be carried out.

According to the sixth aspect, since the mold sand supply tank is hung on the carriage by a plurality of coil springs, the support structure of the mold sand supply tank with respect to the carriage is significantly simplified as compared with the conventional apparatus. , Making it easy to manufacture and assemble.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a casting mold sand quantitative supply device according to the present invention.

FIG. 2 is a partial cross-sectional side view of the same device at a mold sand supply position.

FIG. 3 is a longitudinal sectional side view of the same device at a mold sand supply position.

FIG. 4 is a partial cross-sectional front view of the same device at a mold sand supply position.

FIG. 5 is a rear view of the same device at a mold sand supply position.

FIG. 6 is a cross-sectional plan view of the apparatus at a mold sand supply position.

FIG. 7 is a sectional view taken along line XX of FIG. 6;

FIG. 8 is a sectional view taken along line YY of FIG. 6;

FIG. 9 is a cross-sectional view showing a pivotal connection structure between a piston rod of a bogie driving means and a bogie side.

FIG. 10 is a partial cross-sectional front view of the casting mold sand metering and feeding device at the sand discharging position, showing a state before the sand tank is brought into contact with the mold.

FIG. 11 is a partial cross-sectional front view of the casting mold sand metering and feeding device at the sand discharging position, showing a state in which the sand tank is in contact with the mold.

[Explanation of symbols]

 A-type sand supply position B-type sand discharge position 1 Support frame 2 Die 3 Horizontal beam 4 Dolly 5A Type sand supply position side rail body 5B Type sand discharge position side rail body 9 Type sand supply position side rail body pivot part 10 Weighing device 13 Idling ball 20 type sand supply tank 21 coil spring 23 bogie driving means (fluid pressure cylinder) 25 ball joint

Claims (6)

[Claims] 1. A casting mold sand supply device comprising a mold sand supply tank suspended between a mold sand supply position and a mold sand discharge position and provided to be reciprocally movable, and guides the carriage between the two positions. The guide rail to be separated is divided into a mold sand supply position side rail body and a mold sand discharge position rail body, and the mold sand supply position side rail body is used as a pivot body at an end facing the mold sand discharge position side rail body. The free end of the rail is provided so as to be movable up and down, and the free end of the rail body on the side of the mold sand supply position is supported by a weighing device that weighs a load applied to the rail body. A fixed quantity feeding device for casting mold. 2. The pivoting portion of the rail body on the side of the mold sand supply position,
2. The fixed amount feeding device according to claim 1, wherein the device is formed by a ball bearing and a pivot shaft supported by the ball bearing. 3. The guide rail comprises a pair of both sides of a mold sand discharge position side rail body and a pair of both sides of a mold sand supply position side rail body. A horizontal beam extending parallel to and near the inner surface of each of the rails is supported by idle balls protruding from both sides of the horizontal beam to restrict displacement in the rail width direction. Item 3. An apparatus for quantitatively supplying mold sand for casting according to Item 1 or 2. 4. A supporting rod is projected upward at an intermediate portion in a longitudinal direction of a connecting rod connecting the free ends of the pair of mold sand supply position side rail bodies, and the supporting rod is weighed at a fixed position. 4. The apparatus according to claim 3, wherein the apparatus is supported by a vessel. 5. A bogie driving means for reciprocating the bogie along a guide rail comprises a fluid pressure cylinder interposed between a bogie and a support frame below a mold sand supply position, and a tip end of a piston rod of this cylinder. The part is pivotally connected to the carriage by a ball joint.
5. The apparatus for quantitatively supplying casting mold sand according to any one of claims 4 to 4. 6. The apparatus according to claim 1, wherein the mold sand supply tank is hung on a carriage by a plurality of coil springs.