JP2872099B2 - Vibration device for casting sand filling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating device for filling a molding sand with a vibrating device provided on a table used for vanishing model casting or molding of a self-hardening mold.

[0002]

2. Description of the Related Art In recent years, it has been recognized that the effectiveness of introducing a vibrating table into the disappearing model casting method using dry sand and the filling of molding sand in a self-hardening mold has been recognized, and the results thereof have been gradually increasing. In particular, in the case of molding in the vanishing model casting method,
Although the model is relatively easy to break, the application of the vibration table is indispensable because it is possible to fill the casting sand that is difficult to fill such as the side hole of the model and the lower part of the overhanged part. Has become.

[0003] As the basic ones conventionally used,
There is a vibration table as shown in FIGS. In brief, the configuration is such that a pair of vibrators are attached to the lower surface of a vibration board (table board) 3 supported by a foundation 1 and a spring 2. In the figure, reference numeral 4 denotes a casting frame, which is placed on the upper surface of the vibration plate 3 and is detachably fixed. The vibrator has a rotation unbalanced weight 6 provided on the rotating shaft of an electric motor 5, and an equivalent one is commercially available as a vibration motor. 1
The pair of vibrators are mounted on the lower surface of the vibrating plate 3 so that their axes are horizontal and parallel, as shown in FIG.
6 rotate in opposite directions at a constant speed. As shown in a Lissajous figure 7 showing vibration trajectories at four positions in the flask 4 in FIG. 12, the vibration mode during the operation is such that the entire vibration system is uniform in the Z-axis direction, that is, in the vertical axis direction. It can be seen that an excellent one-axis vibration can be obtained. This device has a long track record and has relatively excellent controllability and stability of vibration form, but since it is a vertical one-axis vibration,
Naturally, in the case of a model having a horizontal perforated portion, the filling property of sand is not preferable.

[0004] For this reason, when more excellent sand filling capacity and fluidization are required, they are not shown in FIGS.
The vibration table shown in FIG. 3 has a configuration in which one or two pairs of vibrators are mounted on the side of the vibration plate 3 so as to vibrate horizontally. The vibration mode in this case is such that a horizontal vibration component in the X-axis or Y-axis direction (when the X-axis and the Y-axis orthogonal to each other in a horizontal plane correspond to each other) is added to the vertical vibration (vibration in the Z-axis direction). , Multi-axis simultaneous vibration. Generally, the vibration frequency in the Z-axis and X-axis directions is adjusted according to the application by inverter control. However, even if the difference between the vibration frequencies fluctuates slightly, the vibration trajectory (Lissajous figure) greatly changes in a complicated manner. Further, even when the operation is performed with the vibrations in the Z-axis and X-axis directions synchronized, it is difficult to maintain a constant phase difference, and the Lissajous figure changes every moment. Such a vibration table to which simultaneous two-axis vibration is applied has problems such as unstable vibration characteristics, poor controllability, and inability to avoid upsizing. In other words, if the vibration characteristics are unstable and the controllability is poor, that is, if the vibration trajectory is unstable and the control is difficult, it is not preferable because the uniform filling action of sand or the intended filling action cannot be obtained. This may cause deformation or breakage of the device, and it is not preferable that the size of the device becomes large, which hinders the operation.

In addition, this type of two-axis vibration type vibration table generally has a configuration in which a vibration source of a horizontal component of vibration is located below the position of the center of gravity of the vibration system. It becomes an offset drive type, and as a result, a yawing phenomenon occurs. The yawing phenomenon in this case is a swing centered on a point called a nodal point such as a fulcrum or a joint of the vibration appearing near the center of gravity of the vibration system. At the nodal point, there is no vibration in the Z-axis and X-axis directions, and the amplitude of the vibration increases as the distance from the nodal point increases. Therefore, a vibration table in which the yawing phenomenon in which the nodal point appears near the center of gravity occurs. ,
If the position is different in the casting flask, the vibration state of the foundry sand is greatly different. Therefore, uniform vibration of the foundry sand in the flask cannot be obtained. This is impractical considering that the vibration characteristics are unstable and the controllability is poor.

Therefore, recently, attention has been paid to the application of a circular vibration along the ZX axis plane which is clear and simple as a trajectory of the multiaxial vibration. In this case, as the initial one, as shown in FIGS. 14 and 15, the same vibration table as the conventional one shown in FIGS. 12 and 13 having a pair of weights 6 is used. To rotate in the same direction. In such a configuration, a constant Lissajous figure is not always obtained, but it has been found later that the Lissajous figure greatly changes due to the difference in the phase difference δ at the weight position, and the phase difference δ is changed during operation. It changes. Each of the Lissajous figures 7 in FIG. 14 is a state when the phase difference δ has a certain value. From the Lissajous figure 7, the vibration of the diaphragm, that is, the yawing phenomenon occurs, and the vibration trajectory of each part is not a perfect circle. It becomes an ellipse, and the size, shape and direction of the ellipse are uneven. Therefore, if such a vibration situation occurs, even if it presents a favorable circular vibration at some point,
It cannot be considered that the vibration table of the circular vibration application type used for actual work has a sufficient function.

Therefore, as shown in FIGS. 16 and 17 as an improved type, an attempt is made to obtain a uniform circular vibration by attaching a vibration motor so that a pair of weights 6, 6 are located near the center of gravity of the whole vibration system. There is an attempt to do. In this case, as is apparent from the Lissajous figure 7 in FIG. 16, it is confirmed that uniform circular vibration is obtained in each portion, and that the flow and filling of sand are good in each portion. However, since the weights 6 and 6 need to be located near the center of gravity, the weights 6 and 6 have a structure that protrudes largely laterally at the upper portion, and thus there is a problem that they hinder the layout of the setup conveyor and the setup work. Further, there is a problem that it is structurally impossible to cope with a change in the weight balance when the use state of the casting flask 4 changes. That is, in a model having a large vertical dimension, the height of the flask is increased, and the position of the center of gravity of the vibration system is also increased. Therefore, the form of excitation becomes an offset type, and the above-described yawing phenomenon occurs.

[0008]

SUMMARY OF THE INVENTION As described above, it is an object of the present invention to provide a method for controlling the weight balance so as not to disturb the peripheral layout and work and to change the use condition of the flask. That is, an object of the present invention is to obtain a circular motion type vibration table that can respond to changes in the height of the center of gravity. In order not to disturb the peripheral layout and work, a rotationally unbalanced vibration device may be provided at the lower portion of the table board as conventionally known, but the configuration can cope with a change in weight balance. An object of the present invention is how to make a circular motion type vibration table.

[0009]

According to the present invention, there is provided a spring-supported vibrating table for filling molding sand capable of fixing a casting flask on a table board, and a two-axis parallel shaft provided at a lower portion of the table board. An unbalanced weight type vibrator in which the respective rotationally unbalanced weights rotate, wherein the unbalanced weights on the two parallel axes maintain a predetermined initial phase difference. And a synchronous rotation means for rotating in the same direction at a constant speed.

According to an experiment related to the present invention, it has been found that the phase difference between the unbalanced weights on the two parallel axes greatly affects the vibration state of each part in the flask. In addition, it has been found that the conventional molding sand filling vibrating apparatus is not operated in a state where the phase difference is reliably constant.
Therefore, as shown in FIGS. 10 and 11, using a device that always maintains a constant phase difference and rotates in the same direction at a constant speed, the phase difference is set to 0 °, 30 °, 60 °, 90 °, 120
°, 150 °, and 180 °, the vibration status of each part was confirmed by experiments. 10 and 11, reference numeral 8 denotes a toothed pulley, reference numeral 9 denotes a timing belt (toothed belt) which is hung on the pulleys 8 and 8, and the other portions are shown in FIGS.
The same parts as those described in FIG. 13 are denoted by the same reference numerals. This device can arbitrarily change the phase difference between the unbalanced weights 6 and 6 by replacing the belt 8, and can reliably operate with a constant phase difference. FIG. 18 shows the result of the confirmation experiment. FIG. 18A shows each vibration measurement position P1, P2, P3,
The Lissajous figure at each phase difference of P4 is shown in FIG.
(B) shows a vibration measurement position on the flask 4 and the table 3.

From the above-mentioned confirmation experiments, it was first found that the vibration state at each part, that is, the vibration trajectory was stable in the operation in which the phase difference was surely constant. It was also found that the same Lissajous figure could be obtained even when the position of the center of gravity of the vibration system was changed up and down. Next, from the results of the confirmation experiment,
As can be seen from the Lissajous figure of FIG. 18A, when the phase difference is 90 °, the vibration measurement positions P1, P2,
It was also found that circular vibrations of P3 and P4 were almost the same as the most preferable perfect circle, and had substantially the same circular vibration. This means that uniform circular vibration is applied to the entire molding sand in the molding flask 4, which is optimal for filling the molding sand. When the phase difference is 60 °, the shape changes slightly vertically in the order of the measurement points P3 (the lower part of the flask 4), P2 (the middle part of the flask 4), and P1 (the upper part of the flask 4). It can be seen that the amplitude in the Z-axis direction is substantially constant and the amplitude in the X-axis direction is decreasing. Also, this tendency is such that as the phase difference decreases to 30 ° and 0 °, the rate of decrease in the amplitude in the X-axis direction increases. From these facts, it can be understood that the nodal point is located at an infinitely far position at a phase difference of 90 °, and approaches the flask from above as approaching 0 °. Further, when the phase difference is 120 °, 150 °
°, when a 180 °, tends to change the horizontal length shape becomes larger than the phase difference 90 ° in this order, change Horizontal strong in the order of the measurement points P4, P3, P2, P1 is a constant phase difference I do. In this case, it can be understood that, as the phase difference approaches from 90 ° to 180 °, the nodal point approaches from below, contrary to the above.

Therefore, the synchronous rotation means of the above-mentioned means stabilizes the vibration trajectory of each part to be substantially constant.
If the initial phase difference is appropriately determined, a stable vibration trajectory corresponding to the phase difference can be obtained. Then, in a special case, it is possible to intentionally vibrate in a state where the horizontal vibration is reduced depending on the place. Also,
The initial phase difference in the means of the present invention, the filling of molding sand emphasizing general uniformity, 30 ° ~ 150 °
The angle is preferably 60 ° to 120 °, more preferably around 90 °.

The synchronizing means may be a toothed belt, a chain or a gear device provided between the two parallel shafts. This ensures that the two parallel axes rotate synchronously.

[0014] The synchronous rotating means of the means may be configured to rotate the two parallel axes by electric motors respectively, and the synchronous rotating means may adjust the phase of both unbalanced weights on the two parallel axes. It is preferable that each of the motors is electrically controlled so that the phase difference between the motors is detected. When the electric synchronous rotation means is applied in this way,
It is less bulky than mechanical synchronous rotation means.

[0015] It is preferable that the vibration device is two rotation-unbalanced vibration motors having rotation axes respectively corresponding to the two parallel axes and fixed to a lower portion of the table board. Since this can use a commercially available vibration motor,
Vibration device for casting sand filling can be easily manufactured.

In the vibration device, the two parallel shafts may be supported by bearings at the lower portion of the table board, and the rotation synchronization means may use a toothed belt, and a motor for rotating the synchronization rotation means may be provided on the table board. It is good to fix to the fixed part outside the vibration system including This is a configuration in which the motor is not included in the vibration system, so that the weight of the vibration system can be reduced by that much, so that the output of the motor may be small and the effect is large in the case of a large vibration table.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, a pair of vibrators are attached to the lower surface of a table board 3 supported by a foundation 1 and a spring 2. In FIG. It is supposed to be. The vibrator is a commercially available vibration motor in which a rotation imbalance weight 6 is provided on the rotating shaft of the electric motor 5. The pair of vibrators are mounted on the lower surface of the vibration table 3 so that their axes are horizontal and parallel, as shown in FIG.
Rotate at the same speed in the same direction. Synchronizing means is provided so that both weights 6, 6 rotate synchronously while maintaining the initial phase difference. The synchronization means attaches the toothed pulleys 8, 8 to the shafts of the motors 5, 5,
The timing belt 9 is hung on the toothed pulley. This embodiment has the same configuration as that for the confirmation experiment described with reference to FIGS. Further, the Lissajous figure 7 shown in the flask 4 of FIG. 1 is obtained when the phase difference between the weights 6 and 6 is 90 °, and shows the vibration state at each position. The arrow in the figure indicates the traveling direction of the timing belt 9.

As shown in each Lissajous figure 7, the vibration mode during the operation is that the entire vibration system is a substantially uniform circular vibration in the Z-axis direction and the X-axis direction. The center position of the oscillating force in this case is located at the midpoint between the two vibration motors, and is far away from the center of gravity of the entire spring-supported vibration system, but the phase difference is reliably maintained at 90 °. A circular vibration can be obtained. The motion direction of the circular vibration is the direction of the arrow shown in the Lissajous figure, which is opposite to the rotation direction of the vibration motor. This Lissajous figure does not change every moment, but is constant and stable. FIGS. 3 and 4 show a case where the rotation direction of the embodiment shown in FIGS. 1 and 2 is reversed. Also in this case, as can be seen from the Lissajous figure 7 shown in FIG. 3, it is recognized that the entire vibration system has substantially uniform circular vibration in the Z-axis direction and the X-axis direction, and is similarly stable.

A second embodiment of the present invention will be described with reference to FIGS. In this embodiment, a vibration device is newly designed for a large cast flask (the weight of the entire vibrating mold is usually about 5 tons at most, but this time about 18 tons). 1 and 2 are denoted by the same reference numerals, and description thereof is omitted. The shaft on which the rotation unbalance weight 6 and the toothed pulley 8 are mounted is supported in parallel and horizontally below the table board 3 by bearings (not shown), respectively, to impart rotation to the timing belt 9 as synchronous rotating means. The motor 10 is fixed to a fixed portion outside the vibration system including the table board 3, for example, to the foundation 1. A toothed pulley 8a is attached to the tip of the rotating shaft 11 of the motor 10, a timing belt 9 is hung around the toothed pulleys 8, 8, 8a with a margin, and two tension pulleys 8b are separately provided. This is the timing belt 9
When the table board 3 is displaced while being hooked on the toothed pulley, tension is applied so that the meshing state between the timing belt 9 and the toothed pulleys 8, 8, 8a can be maintained.

In the second embodiment, the initial phase difference between the weights 6 and 6 is set to 90 °, and the vibration mode caused by the operation is not shown, but is similar to that of the first embodiment. At four points, circular vibration was observed, and extremely good results were obtained even in a practical test. Further, since the number of the motors 10 can be reduced to one, and the motor is not attached to the table board 3, the weight of the spring-supported portion, that is, the weight of the vibration system can be reduced, so that the spring-supported weight is reduced. . Therefore, as compared with the configuration using two vibration motors, it is advantageous in terms of manufacturing cost, and the size of the vibration device can be increased.
It is excellent in that it can be made compact.

A third embodiment of the present invention will be described with reference to FIGS. In this embodiment, a gear device is provided in place of the toothed pulleys 8 and 8 and the timing belt 9 as the synchronous rotation means in the first embodiment. The gear device includes gears 8c, 8c attached to the rotating shafts of the respective motors 5, gears 8d, 8d meshing with the gears, and one gear 8e meshing with both the gears 8d, 8d, One gear 8c and the other gear 8c surely rotate in the same direction in synchronization. Each gear 8d, 8e, 8d is connected to the table board 3
The bearing is supported on the lower surface. Since the other configuration is the same as that of the first embodiment, the same parts are denoted by the same reference numerals and the description thereof is omitted.

In this embodiment, a Lissajous figure is not shown, but a favorable circular vibration is produced as in the first embodiment. Good results were also obtained in practical tests.

FIG. 9A shows a fourth embodiment of the present invention.
A fifth embodiment will be described with reference to FIG. In these embodiments, the first embodiment described with reference to FIGS.
Instead of the pulleys 8 and 8 and the timing belt 9 as the synchronous rotation means in the embodiment shown in FIG.
As shown in the block diagram of (a) or (b), each is a configuration using an electric synchronous rotating means. In FIG. 1 and FIG. 2, the electric motors 5 and 5 and the unbalanced rotation weights 6 and 6 are shown in FIGS. 1 and 2, but the motors 5a and 5b and the unbalanced rotation weight 6a are used to distinguish the two motors and the weight. , 6b. 9 (a) and 9 (b) both detect the phase of the rotationally unbalanced weight 6a, which is rotationally driven by the motor 5a, with the pulse detector PGa, and the rotationally unbalanced, which is rotationally driven by the motor 5b. The phase of the weight 6b is detected by the pulse detector PGb, and the control device 20 or 30 controls the motors 5a and 5b based on both detection signals so that the phase difference between the unbalanced weights 6a and 6b becomes constant. Control devices 20 and 3
0 has a different configuration, and that point will be described below.

The control device 20 shown in FIG. 9A has an adjusting unit 21, a driving unit 22, a phase comparing unit 23, an adjusting unit 24, and a driving unit 25. The speed command for the motor 5a is
The driving unit 22 is supplied to the driving unit 22 via the adjustment unit 21 and supplies the electric power from the power supply to the motor 5a in accordance with the instruction to rotate the rotation imbalance weight 6a. Further, a speed command for the motor 5b is given to the drive unit 25 via the adjustment unit 24, and the drive unit 25 supplies power from the power source to the motor 5b in accordance with the command, and the rotation unbalance weight 6
Rotate b. The phase comparison unit 23 includes a pulse detector PG
The phases are compared based on the detection signals from a and PGb, and the result is given to the adjustment units 21 and 24. The adjusting units 21 and 24 adjust the speed command so that the phase difference between the unbalanced weights 6a and 6b becomes a predetermined phase difference (for example, 90 °) based on the result of the phase comparison, and give the speed command to the driving units 22 and 25. The motors 5a and 5b are controlled such that the phase difference between the unbalanced weights 6a and 6b becomes a predetermined phase difference of 90 °.

The control device 30 shown in FIG. 9B has a comparing unit 31, a driving unit 32, a phase comparing unit 33, an adjusting unit 34, and a driving unit 35. The speed command for the motor 5a is
The driving unit 32 supplies the electric power from the power supply to the motor 5a in accordance with the instruction, and rotates the rotation imbalance weight 6a at a predetermined rotation speed. A signal from the pulse detector PGa that detects the phase of the unbalanced weight 6a is fed back to the comparison unit 31, and the comparison unit 31 receives the signal as a rotation speed and compares the signal with the rotation speed of the speed command. Then, a speed command is given to the drive unit 32 so that the rotation speed of the motor 5a is maintained at a predetermined rotation speed. Therefore, the motor 5a is always maintained at a predetermined rotation speed. The speed command for the motor 5b is given to the drive unit 35 via the adjustment unit 34, and the drive unit 35 supplies power from the power
To rotate. The phase comparison unit 33 includes a pulse detector PGa,
The phases are compared based on the detection signal from PGb, and the result is provided to the adjustment unit 34. The adjusting unit 34 adjusts the speed command so as to have a phase difference (for example, 90 °) between the unbalanced weights 6a and 6b determined in advance from the phase comparison result and gives the speed command to the driving unit 35, whereby the unbalanced weight 6a is adjusted. , 6b
The motor 5b is controlled so that the phase difference becomes a predetermined phase difference (90 °). In this case, since the motor 5a is always maintained at a predetermined rotation speed, the result of the phase comparison is a phase shift of the unbalanced weight 6b with respect to the unbalanced weight 6a, and the shift is the motor 5b It is to be corrected on the side.

The fourth and fifth embodiments do not show a Lissajous figure, but perform favorable circular vibrations as in the first embodiment.

In each of the first to fifth embodiments, a substantially uniform circular vibration along the ZX axis plane can be obtained at any position of the whole vibration system. The side holes and overhangs are not necessarily oriented along a certain vertical plane. For example, when one mold model has lateral holes in the X-axis direction and the Y-axis direction, it is not possible to simultaneously fill both lateral holes with molding sand well. In such a case, a similar vibration device can be provided so as to vibrate along the ZY axis plane in addition to the vibration device described in the embodiment. Part 2
The operation of the set of vibrating devices may be performed sequentially or simultaneously. When they are performed at the same time, a combined vibration occurs.
Since the circular vibration along the X-axis plane and the circular vibration along the Z-Y-axis plane are combined, the vibration components in both the X-axis direction and the Y-axis direction are included at substantially the same level. The uniformity of the filling of the foundry sand into the lateral holes in the direction is not impaired. In some cases, it is conceivable to change the vibration table board of the first to fifth embodiments to a position in which only the upper surface portion is rotated by 90 ° about the Z axis with respect to the vibration device. Then, it is not necessary to provide another set of vibration devices.

[0028]

According to the first aspect of the present invention, the unbalanced weights on the two parallel axes rotate in the same direction at a constant speed while reliably maintaining a predetermined initial phase difference, and are perpendicular to the two parallel axes. Since a stable vibration form in the direction along the plane can be obtained, by selecting the initial phase difference, a uniform circular vibration as a whole, or a vibration in which the Lissajous figure becomes circular to vertically elongated as the lower part goes upward with circular vibration Or, conversely, vibrations in which the upper portion becomes horizontally long can be intentionally generated, and the most effective form of vibration can be performed for filling the molding sand according to the shape of the mold model. It has the effect of being able to fill the molding sand without damaging the model in the production of the mold. Further, since the vibrating device is provided at the lower portion of the table board, it has an effect of not disturbing the layout and work around the vibrating device. According to a second aspect of the present invention, the predetermined initial phase difference is 3
By setting the angle within the range of 0 to 150 degrees so that the entire vibration system vibrates almost circularly, the molding sand to be filled is equal in the vertical and horizontal directions at any position in the casting frame. It flows under a strong acting force, and has an effect that the molding sand is filled well even if the model has horizontal holes or vertical holes. According to the third aspect of the present invention, since the synchronization means is a timing belt and a toothed pulley, it can be easily manufactured and a synchronous rotation with an initial phase difference is reliably obtained. The effect is obtained. According to the fourth aspect of the present invention, since the synchronizing means is a gear device, it can be manufactured easily, and a synchronous rotation with a reliable initial phase difference can be obtained. Play. The invention according to claim 5 has an effect that when the electric synchronous rotating means is applied in this manner, the electric synchronous rotating means is less bulky than the mechanical synchronous rotating means. The invention according to claim 6 is
Since the vibration device is two rotation-unbalanced vibration motors, there is an effect that a vibration device for filling molding sand can be easily provided by using a commercially available vibration motor. Claim 7
According to the invention described in (1), the vibration device gives rotation to two parallel axes by one motor provided on a fixed portion outside the vibration system, so that the weight of the vibration system is reduced by that much, and the manufacture becomes easy. This has the effect that a larger mold can be made than before.

[Brief description of the drawings]

FIG. 1 is a front view schematically showing a first embodiment of the present invention together with a Lissajous figure.

FIG. 2 is a plan view schematically showing the same embodiment.

FIG. 3 is a front view schematically showing a Lissajous figure when the motor of the embodiment is rotated in a direction opposite to that of FIG. 1;

FIG. 4 is a plan view corresponding to FIG.

FIG. 5 is a front view schematically showing a second embodiment of the present invention.

FIG. 6 is a plan view schematically showing the same embodiment.

FIG. 7 is a front view schematically showing a third embodiment of the present invention.

FIG. 8 is a plan view schematically showing the same embodiment.

FIG. 9A is a block diagram illustrating a schematic configuration of a synchronous rotation unit according to a fourth embodiment of the present invention, and FIG. 9B is a schematic diagram of a synchronous rotation unit according to a fifth embodiment of the present invention. FIG. 3 is a block diagram illustrating a configuration.

FIG. 10 is a front view schematically showing a molding sand filling vibrating device used in an experiment relating to the present invention.

FIG. 11 is a plan view corresponding to FIG.

FIG. 12 is a front view schematically showing a conventional molding sand filling vibrating apparatus.

FIG. 13 is a plan view corresponding to FIG.

FIG. 14 is a front view schematically showing a conventional molding sand filling vibrating apparatus.

FIG. 15 is a plan view corresponding to FIG.

FIG. 16 is a front view schematically showing a conventional molding sand filling vibrating apparatus.

FIG. 17 is a plan view corresponding to FIG.

18 (a) is a graph (Lissajous figure) showing each vibration form at the vibration measurement position shown in (b) when the apparatus shown in FIGS. 10 and 11 is operated while changing the phase difference,
(B) is a cast-frame front view which shows a vibration measurement position.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 foundation 2 support spring 3 table board 4 cast frame 5 motor 5a motor 5b motor 6 unbalanced weight 6a unbalanced weight 6b unbalanced weight 7 lissajous figure 8 toothed pulley 8a toothed pulley 8b tension pulley 8c gear 8d gear 8e gear 9 Timing belt 10 Motor 11 Motor shaft 20 Control device 30 Control device PGa pulse detector PGb pulse detector

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-90160 (JP, A) JP-A 8-90161 (JP, A) (58) Fields surveyed (Int.Cl. ⁶ , DB name) B22C 15/10

Claims (7)

(57) [Claims] 1. A spring supported casting sand filling vibration table capable of fixing a flask to a table board, and respective unbalanced rotations on two parallel axes provided at a lower portion of the table board are rotated. in the vibration apparatus for sand-and a non counterweight vibrating apparatus, the vibrator, while maintaining the initial phase difference at <br/> constant unbalance weights on the two parallel axes different phases A molding sand filling vibrating device provided with synchronous rotating means for rotating in the same direction at a constant speed. 2. The molding sand filling vibrating device according to claim 1, wherein the initial phase difference is in a range of 30 degrees to 150 degrees. 3. The molding sand filling vibrating device according to claim 1, wherein said synchronization means comprises:
A vibrating device for filling molding sand, which is a toothed belt or chain hung between shafts. 4. The molding sand filling vibrating device according to claim 1, wherein the synchronizing means includes the parallel 2
A vibration device for filling molding sand, which is a gear device provided between shafts. 5. The molding sand filling vibrating device according to claim 1, wherein said parallel two axes are respectively driven to rotate by an electric motor, and said synchronous rotating means is said parallel two axes. A vibrating apparatus for filling molding sand, characterized in that the phases of the above unbalanced weights are detected and each of the motors is electrically controlled so that the phase difference between the two is constant. 6. The vibration device for filling molding sand according to claim 1, 2, 3, or 4, wherein the vibration device has a rotation axis corresponding to each of the two parallel axes. A vibration device for filling molding sand, which is a basic rotationally unbalanced vibration motor and fixed to a lower portion of the table board. 7. The vibrating device for filling molding sand according to claim 1, 2, 3, or 4, wherein the vibrating device supports the two parallel axes on a lower portion of the table board, respectively. A vibration device for filling molding sand, wherein a motor for rotating the synchronous rotating means is fixed to a fixed portion outside the vibration system including the table board.