JP3248895B2 - 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 molding of a mold for use in a burnout model casting method using dry sand containing no binder.
The present invention relates to a molding sand filling vibrating device used for molding a self-hardening mold using self-hardening sand containing a binder.

[0002]

2. Description of the Related Art In recent years, there has been developed a technique of molding a mold sand of this type by using a vibrating device based on a rotationally unbalanced weight to apply a circular vibration to a casting frame and to fill molding sand with good speed. For example, an apparatus as shown in FIG. 3 is used. Explaining this, the configuration is such that a pair of vibrators 5 are attached to the lower surface of the table 3 supported by the foundation 1 and the spring 2. In the figure, reference numeral 4 denotes a casting frame which is clamped on the upper surface of the table board 3. The vibrator 5 is a vibration motor provided with a rotationally unbalanced weight 6 on a rotating shaft of an electric motor. The pair of vibrators 5, 5 have their axes horizontal and parallel, and the weights 6, 6 are synchronized at the same speed and in the same direction while maintaining a predetermined phase difference δ (for example, 90 °). Synchronous rotation means is provided so as to rotate. The synchronous rotation means is provided with toothed pulleys 8 and 8 on a shaft of a motor and a timing belt 9 is hung thereon. The Lissajous figure 7 shown in the flask 4 in FIG. 3 is obtained when the phase difference δ 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.

[0003] In this molding sand filling vibrating apparatus, as shown in Lissajous figure 7, the whole vibration system makes a circular vibration that draws a substantially uniform circle along a plane (ZX plane) perpendicular to the motor axis. . When the phase difference δ is changed to be larger or smaller than 90 °, the circular vibration changes to an elliptical shape in a direction away from a perfect circle as shown in FIG. 4 (a). A range of 30 to 150 ° seems to be good. FIG. 4B shows the measurement positions P1 to P1 of each Lissajous figure in FIG.
P4 is shown.

[0004]

In the conventional vibrating apparatus for filling foundry sand, when the size is increased, it is necessary to increase the output of each vibrator in which the unbalanced weight rotates on two parallel axes. is there. For example, when the casting exceeds 5 tons, the weight of the mold is two to three times that of the casting, and a vibrator with a considerably large output is required to vibrate a heavy object exceeding 10 tons. Even if a high-output shaker can be manufactured, there is a problem that it is expensive. Further, it is necessary to increase the rigidity of the entire vibrating section including the table board. If the rigidity is low, the table board may vibrate while flexing to generate a preferable circular vibration in the entire vibration system. Since it is not possible, there is a problem that the molding sand cannot be hardened. To solve this problem, if the thickness of the table board is increased as much as necessary to increase the rigidity, the weight increases and the position of the center of gravity increases, making it difficult to generate uniform circular vibration. It is difficult in terms of price and technology. An object of the present invention is to provide a molding sand filling vibrating device that can be made large.

[0005]

According to a first aspect of the present invention, there is provided a vibrating apparatus for filling molding sand with which a casting frame can be fixed on a table board. An unbalanced weight type vibrating device having four or more parallel axes each having a rotationally unbalanced weight provided at a lower portion of the device, wherein half of the unbalanced weights rotate in the same phase and the other half are the same. Synchronous rotation means provided so as to rotate in the same direction as the rotation while maintaining a predetermined initial phase difference at a phase different from the phase (claim 1).

With this means, circular vibration can be applied to the entire molding sand in the casting flask in the same manner as the conventional one described with reference to FIG. 3, and for example, when the predetermined initial phase difference is 90 °, Can apply a substantially circular vibration to the entire molding sand in the casting frame, and can form a good mold. And
Since the axes of the rotationally unbalanced weights are four or more, it is possible to disperse and arrange a larger number of rotationally unbalanced weights than in the prior art, whereby a vibrating device for filling molding sand having the same vibrational output is provided. In this case, it is possible to reduce the size of each of the rotation-unbalanced weight rotating parts, and to disperse the portions where the vibration is transmitted to the table board, so that the rigidity required for the table board may be further reduced. Things. Therefore, since there is a margin in securing the rigidity required for the table board in increasing the size, it is possible to provide a molding sand filling vibrating apparatus capable of molding a larger mold than before.

A vibration device for filling a foundry sand according to a second aspect of the present invention comprises:
A spring supported casting sand filling vibrating table capable of fixing the flask to a table board, and a plurality of parallel shafts each having a rotationally unbalanced weight so that the unbalanced weights rotate in the same phase. An unbalanced weight vibrating device comprising two sets of configured vibrating units, and the two sets of vibrating units are provided below the table board with their respective axes parallel to each other, and the unbalanced weights have different phases between the units. Synchronous rotating means provided so as to rotate in the same direction at a constant speed while maintaining a predetermined initial phase difference (claim 2).

With this means, circular vibration can be given to the entire molding sand in the flask in the same manner as the conventional one described with reference to FIG. 3, and for example, when the predetermined initial phase difference is 90 °, Can apply a substantially circular vibration to the entire molding sand in the casting frame, and can form a good mold. And
Since each of the vibration units has a plurality of parallel axes rotating in the same phase with a rotationally unbalanced weight, a configuration in which a larger number of rotationally unbalanced weights are dispersed and arranged than in the related art becomes possible. In the case of a molding sand filling vibrating device having the same vibration output, the size of each of the rotationally unbalanced weight rotating parts can be made smaller than before, and the places where the vibration is transmitted to the table board are dispersed. Therefore, the rigidity required for the table board may be smaller. Therefore, since there is a margin in securing the rigidity required for the table board in increasing the size, it is possible to provide a molding sand filling vibrating apparatus capable of molding a large mold.

A third vibrating apparatus for filling molding sand of the present invention comprises:
A spring-supported vibrating table for filling molding sand capable of fixing a flask on a table board, and an unbalanced weight in which respective rotationally unbalanced weights on two parallel axes provided at a lower portion of the table board rotate. And a synchronous rotation means provided in the vibration device for rotating the unbalanced weights on the two parallel axes in the same direction at a constant speed while maintaining a predetermined initial phase difference of different phases. In the molding sand filling vibrating device, the unbalanced vibrating device includes a second shaft having a rotationally unbalanced weight provided in parallel corresponding to each of the two parallel axes, and a second second shaft. And a second synchronous rotation means provided so that the unbalanced weight of the shafts rotates in the same phase as the corresponding one of the two parallel shafts (claim 3).

With this means, circular vibration can be applied to the entire molding sand in the molding flask in the same manner as the conventional one described with reference to FIG. 3, and for example, when the predetermined initial phase difference is 90 °, Can apply a substantially circular vibration to the entire molding sand in the casting frame, and can form a good mold. And
Since the unbalanced weight has a second axis that rotates in the same phase as the corresponding one of the two parallel axes, a configuration in which a larger number of rotationally unbalanced weights than in the related art can be arranged in a dispersed manner is possible, thereby the same In the case of a molding sand filling vibrating device having a vibration output, it is possible to reduce the size of each rotation unbalanced weight rotating part, and also to disperse the place where vibration is transmitted to the table board, so that The required stiffness may be smaller. Therefore, since there is a margin in securing the rigidity required for the table board in increasing the size, it is possible to provide a molding sand filling vibrating apparatus capable of molding a large mold.

[0011]

FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to (a) and (b). In this embodiment,
Vibrating table 10, vibrating device 11, synchronous rotating means 1
And 2. The vibration table 10 has a foundation 13
And table board 1 supported by four air springs 14
5 is comprised. The air spring 14 may use a metal spring instead. In the figure, reference numeral 16 denotes a casting frame which is clamped on the upper surface of the table board 15.

The vibrating device 11 is a normal type that generates vibration by rotating an unbalanced weight, and has a structure in which two sets of vibrating units 17 and 18 having no rotation drive unit are attached to the lower surface of the table 15. In addition, one electric motor 19 as a rotation drive unit is provided on the base 13 and is rotated by this. The vibration units 17 and 18 are the same, and include a plurality of vibrators, for example, two vibrators 2.
1 and 22. Each of the vibrators 21 and 22 has an unbalanced weight 23 attached to a shaft, and the shafts are supported in parallel by respective bearings 24.
Similarly, the vibration unit 18 is provided with a toothed pulley 25 on the shaft so that the unbalanced weights 23 of the two vibrators 21 and 22 rotate synchronously in the same direction in the same phase. A belt (timing belt) 26 is hung. Each vibrator 21 of the two vibration units 17 and 18
All 22 axes are parallel.

The synchronous rotating means 12 includes an unbalanced weight 23
Of each of the two vibration units 17 and 18 so as to rotate synchronously while always maintaining a predetermined phase difference δ.
A toothed pulley 27 is further provided on one of the two shafts 7, 18 and a toothed pulley 28 is provided on the shaft of the electric motor 19, and a toothed belt 29 is mounted on these toothed pulleys 27, 27, 28. It is hung. Although not shown,
A tension pulley, which is separately biased by a spring and elastically presses against the toothed belt 29, is provided. The toothed belt 29 is provided with the toothed belt 29 even if the table board 15 is displaced. The tension is applied so that the meshing state with the gear 28 can be maintained.

FIG. 2A shows a second embodiment of the present invention.
This will be described with reference to FIG. In this embodiment, the vibration table 10 is the same as in the first embodiment, but the vibration device 11a and the synchronous rotation means 12a are slightly different. Explaining this point, the vibration device 11a
A pair of vibration units 31 and 32, each of which is composed of three vibrators 33,
Has an electric motor 34 built-in, and the shaft of the motor 34 protrudes on both sides, and unbalanced weights 3
5 and 35. The toothed pulley 3 having the same number of teeth is attached to one end of the shaft of each motor 34 as the synchronous rotating means 12a.
6, or 36 and 37 are provided, and adjacent ones are sequentially connected by a toothed belt 38 or 39. The connection state is such that the unbalanced weight 35 of each vibrator 33 is set to the same phase for each of the vibration units 31 and 32, and the toothed belt 38 is used.
And the unbalanced weight 35 between the vibration units 31 and 32 is set to a predetermined initial phase difference δ (for example, 90
°) with a toothed belt 39.

In this embodiment, the synchronous rotating means 12a is provided with a vibrator 3 connected by a toothed belt 39.
Assuming that the axis of No. 3 is a conventional two parallel axis (first axis), the axis of the other vibrator 33 is regarded as the second axis, and the toothed belt 39 is rotated by the synchronous rotation means (first axis). Synchronous rotating means), the toothed belt 38 which connects the two parallel axes and the second axis to form the units 31 and 32 can be regarded as the second synchronous rotating means. The same can be said for the first embodiment.

In the first and second embodiments, between the vibration units 17 and 18 of the unbalanced weight 23 or 35,
Or the initial phase difference δ between 31 and 32 is 90 °,
Although not shown, the vibrations caused by the operation are circular vibrations at all four positions on the upper, lower, left and right sides of the casting flask 16, and extremely good results were obtained in a practical test. In the first embodiment, four vibrators 21 and 22 are used to obtain the required vibration. However, one electric motor 19 can be used, and no motor is attached to the table 15. With this configuration, the weight of the portion supported by the spring, that is, the weight of the vibration system can be reduced, so that the weight of the spring supported is reduced. In addition, compared to the case where two vibrators having the same configuration as the vibrators 21 and 22 and having a large capacity are used to obtain the same vibration,
Since the mounting positions of the vibrator can be dispersed, the vibration can be transmitted from the dispersed positions of the table 15, whereby the deflection of the table 15 due to the vibration transmission can be reduced, and the table 15 can be formed thinner accordingly. Because
The molding sand filling vibrating device can be formed in a larger size, and when the molding sand filling vibrating device is large and has the same capacity, it is advantageous in terms of manufacturing cost. Although four vibrators were used, in some cases, six or eight vibrators can be used, and a smaller vibrator can be used with the same vibration output, and the vibrators are further dispersed and arranged. In this respect, a greater effect can be obtained.

In the second embodiment, six vibrators 33 with electric motors are used to obtain necessary vibrations. As compared with the case where the same vibration output is obtained by using a plurality of pieces, the mounting positions of the vibrators can be dispersed, so that the vibration can be transmitted from the dispersed positions at the lower portion of the table board 15, whereby the table board 15 can be transmitted by the vibration transmission. Since the bending can be reduced and the table board 15 can be formed thinner accordingly,
The vibrating device for casting sand filling can be made larger.
Although six vibrators 33 with an electric motor were used,
As in the first embodiment, depending on the case, a configuration using four or eight vibrators 33 may be used.

In the above embodiment, the phase difference δ between the units of the unbalanced weights 23 and 35 is 90
°, but the phase difference δ is 60 ° or 120 °
When this is changed to an ellipse, a nearly elliptical Lissajous figure similar to the one shown in FIG. 4A is obtained. In the above-described embodiment, the configuration has been described in which the synchronous rotating means 12a uses a toothed pulley and a toothed belt. Alternatively, a mechanical synchronous rotating means such as a sprocket and a transmission by a chain or a gear may be used. If a vibrator with an electric motor is used as in the second embodiment, a well-known electric synchronous rotating means may be used.

In each of the first and second embodiments, a substantially uniform circular vibration along the ZX axis plane can be obtained at any position of the entire vibration system. The side holes and overhangs are not necessarily oriented along a certain vertical plane. For example, if 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, in addition to the molding sand filling vibrating device shown in the embodiment, a similar device can be provided so as to vibrate along the ZY axis plane. The operations of the two sets of devices may be performed sequentially or simultaneously. Simultaneous vibration results in combined vibration. However, since vibration is a combination of circular vibration along the ZX axis plane and circular vibration along the ZY axis plane, vibration in either the X axis direction or the Y axis direction Since the components are contained to the same extent, the uniformity of filling the molding sand into the horizontal holes in each direction is not impaired. In some cases, the first,
A configuration in which only the upper surface portion of the table board of the second embodiment is rotated by 90 ° around the Z-axis with respect to the vibrating device can be considered. In this case, another set of vibrating devices is not required. Is also good.

[0020]

According to the first to third aspects of the present invention, there is provided a vibrating apparatus for filling a molding sand capable of molding a large mold because the rigidity required for the table board can be reduced as compared with the conventional one. The effect that can be performed.

[Brief description of the drawings]

FIGS. 1A and 1B schematically show a first embodiment of the present invention, wherein FIG. 1A is a schematic front view and FIG. 1B is a schematic plan view.

FIGS. 2A and 2B schematically show a second embodiment of the present invention, wherein FIG. 2A is a schematic front view and FIG. 2B is a schematic plan view.

FIG. 3 is a schematic front view schematically showing a conventional molding sand filling vibrating apparatus.

4A is a graph (Lissajous figure) showing each vibration mode at the vibration measurement position shown in FIG. 3B when the molding sand filling vibration apparatus shown in FIG. 3 is operated while changing the phase difference,
(B) is a cast-frame front view which shows a vibration measurement position.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration table 11 Vibration device 12 Synchronous rotation means 13 Foundation 14 Air spring 15 Table board 16 Cast frame 17, 18 Vibration unit 19 Electric motor 21, 22 Vibrator 23 Unbalanced weight 24 Bearing 25, 27, 28 Toothed pulley 26, 29 toothed belt 31, 32 vibration unit 33 vibrator 34 motor 35 unbalanced weight 36, 37 toothed pulley 38, 39 toothed belt

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuhiro Sato 4-chome, Kanbei-cho, Otsu-ku, Himeji-shi, Hyogo Pref. 72) Inventor Yoshihiko Tsukada 1-9-22 Tsuji, Shimizu City, Shizuoka Prefecture Inside Toyo Kikai Seisakusho Co., Ltd. (72) Inventor Shigeki Tsuboi 1-9-22 Tsuji, Shimizu City Shizuoka Prefecture Inside Toyo Kikai Seisakusho Co., Ltd. 56) References JP-A-9-225586 (JP, A) JP-B-42-27028 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B22C 11/00-25/00 B06B 1/00-3/04

Claims (3)

(57) [Claims] 1. A spring-supported vibrating table for filling molding sand capable of fixing a flask to a table board, and four parallel axes provided at a lower portion of the table board, each having a rotationally unbalanced weight or An unbalanced weight vibrating device having more shafts, half of the unbalanced weights rotate in the same phase and the other half maintain the predetermined initial phase difference in the same phase and a phase different from the phase And a synchronous rotating means provided so as to rotate in the same direction as the rotation. 2. A spring-supported vibrating table for filling molding sand capable of fixing a flask to a table board, and a plurality of parallel shafts each having a rotationally unbalanced weight, the unbalanced weights having the same phase. An unbalanced weight type vibrating device comprising two sets of vibrating units configured to rotate with each other; and the two sets of vibrating units are provided at a lower portion of the table board with their respective axes parallel to each other. A synchronous rotating means provided so as to rotate in the same direction at a constant speed while maintaining a predetermined initial phase difference having a different phase between them. 3. A spring-supported vibrating table for filling molding sand capable of fixing a flask to a table board, and respective rotationally unbalanced weights on two parallel axes provided at a lower portion of the table board. A rotating unbalanced weight vibrating device, and a synchronous rotation provided on the vibrating device so that the unbalanced weights on the two parallel axes rotate in the same direction at a constant speed while maintaining a predetermined initial phase difference of different phases. Means for filling molding sand with means, wherein the unbalanced vibrating device has a second shaft having a rotationally unbalanced weight provided in parallel corresponding to each of the two parallel shafts; A second synchronous rotating means provided so that the unbalanced weights of the respective second shafts rotate in the same phase as the corresponding ones of the two parallel shafts. .