JP2959204B2 - Vibrating drum - 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 drum suitable for use in, for example, mixing, drying and cooling of bulk materials, and particularly suitable for separating sand from castings.

[0002]

2. Description of the Related Art FIGS. 11 and 12 show a conventional vibrating drum used for separating a casting from sand. In FIG. 11, the vibrating drum is indicated as a whole by 70 and has a substantially cylindrical shape. A drive unit mounting frame 72 is fixed to a support base 75 via a driving spring 74 for resonance on the side of the drum main body 71, and the support base 75 is connected to the drum main body 71 via a plurality of mounting ribs 86. It is fixed to.

A supply port 85 for supplying a casting to be sanded is provided at the left end of the drum body 71 in FIG. 11, and a discharge port for discharging the sanded casting is provided at the right end. An outlet 84 is formed. Both sides of the drum main body 71 are closed by end walls 82a and 82b.

[0004] The entire drum body 71 is made up of vibration isolating springs 76a, 7a.
6b, 77a, and 77b support the ground E so that it can vibrate. A vibration source 73 including a pair of vibration motors 79a and 79b as a driving unit is fixed to the frame 72. The vibrating motors 79a, 79b are constructed in a known manner, but their semi-circular unbalanced weights 80a, 80b are fixed to their rotating shafts 81a, 81b. Frame 72
, But unbalanced weights 80a, 8
0b is fixed to the rotation shafts 81a and 81b with the same rotation phase. A dust collecting duct 7 is provided on the upper wall of the drum body 71.
8 is fixed and communicates with the inner space 87 so as to guide dust generated due to sanding of the casting in the drum body 71 to the outside as described later. The entire vibration drum 70 is inclined several degrees downward toward the discharge port 84.

[0005] The vibration drum 70 of the conventional example is configured as described above. When the vibrating section 73 is driven, the vibration motors 79a and 79b rotate synchronously. The pair of vibration motors 79a and 79b are driven to rotate at a frequency close to the resonance frequency determined by the constant, the mass of the entire drum body 71, the mass of the vibrating section 73, and the like. This rotation generates a linear vibration force in the direction in which the spring 74 extends, and this is transmitted to the drum main body 71 via the spring 74 and the support base 86. Since the drum body 71 is supported by the vibration-proof springs 76a, 76b, 77a, and 77b so as to be able to vibrate, the drum body 71 vibrates in an oblique direction in the direction indicated by the arrow, whereby the casting M and the sand S in the inner space 87 of the drum body 71 Perform a circulating motion as indicated by the arrows. Since the drum main body 71 is inclined downward several degrees toward the discharge port 84, the sand S and the casting M move toward the discharge port 84 together with the circulating motion indicated by the arrow in FIG. In this process, sand is separated, and the separated casting M and sand S are separated and discharged from the discharge port 84.

The conventional vibrating drum 70 has the above-described structure and operates. However, other types of casting-type sand removers, for example, for supplying a casting to be sanded to a scaly floor. Then, the separated sand is discharged downward by linear vibration, and the sand is transferred over the floor by linear vibration.However, in this type of casting sand remover, impact is applied to the casting. Therefore, there is a disadvantage that the sand does not fall off depending on the shape of the casting because there is not much change in the posture (reversal, etc.) of the casting. Is removed, but a pair of vibration motors 79
a and 79b are not always synchronized, and when they are out of synchronization, an irregular vibration force is applied to the drum main body 71, so that the above-described operation is not performed and sufficient sanding cannot be performed. Of course, it will have the same disadvantages as the other types of sand removers described above. For example, the casting M may be damaged. In order to cope with this, strict setting standards are required for the mounting positions of the vibration motors 79a, 79b with respect to the drum main body 71 and the arrangement of the springs 74 so that the vibration motors 79a, 79b rotate synchronously. Therefore, not only is the vibration drum 70 shown in FIGS. 11 and 12 expensive, but also a resonance state can be obtained depending on the total weight and the mass distribution of the casting M and the sand S to be sanded in the drum main body 71. In some cases, synchronous rotation cannot be performed.

[0007] As another type of casting sand remover, there is a so-called rotary drum in which a drum is rotated at a predetermined speed in a fixed direction. When the sand is separated, the casting is lifted by scratching. When it is hit, it goes to a certain height and falls, and this impact may damage it. In addition, since the contact time with the casting is long, the sand and the additives are aged. Further, as described above, noises are generated because drops due to scratching or the like occur periodically. Although this conventional example is excellent for such difficulties, it still has the points to be improved as described above.

FIGS. 13 and 14 show other conventional examples. Parts corresponding to the above-mentioned conventional example are denoted by the same reference numerals, and detailed description thereof will be omitted. That is, in the conventional example, the vibration mechanism 73 for generating the linear vibration force is attached to the peripheral wall portion of the drum main body 71 as described above, and this is a pair of vibration motors 82A and 82A.
2B, which are fixed to the mounting base 95. Gears 89a, 89b of the same diameter and the same number are fixed to one end of each of the rotating shafts 83a, 83b, and further mesh with them. A gear 90 having a small diameter but the same diameter and the same number
a and 90b are rotatably mounted on the bearing housing 88 'so that the shafts thereof are rotatable, and the respective vibration motors 82A and 82B are connected to the respective power cords 85 and 85 so that AC power is connected thereto, so that the vibration motors 82A and 82B are in opposite directions. These are driven by the gears 90a, 90b and the large-diameter gears 89a, 89b.
The semicircular unbalance weights 84a, 84b fixed to one ends of the a and 83b rotate synchronously at the same speed in opposite directions. As a result, as shown in FIG.
-Generate a linear vibration force in the X direction.

The other conventional example has a simpler structure than the above conventional example, but has the following disadvantages.

Also in this conventional example, the drum main body 71 has a cylindrical shape, and the casting that separates sand is transferred along the axis C of the drum main body.
a and 77b, and also in this conventional example, a vibrator 73 also composed of two vibrating motors 82A and 82B.
Is attached to the peripheral wall of the drum main body 71.

Also in this conventional example, each vibration motor 82A, 8A
Semi-circular unbalanced drive shafts 83a and 83b
The weights 84a and 84b are fixed, and the drive shaft 83
A gear having the same shape and the same number of teeth is fixed to one end of each of the a and 83b, and these gears are meshed with each other. Therefore, the two vibration motors 82A and 82B are synchronized at different speeds at different speeds. Rotate. As a result, as shown in FIG. 15, a linear vibration force is generated in the direction of arrow P, which intersects the axis C almost at right angles. Thus, when the casting to be sanded has not yet been introduced into the drum main body 71, that is, when there is no load, each point on the peripheral wall of the drum main body 71 performs a linear vibration as indicated by an arrow. However, this direction is substantially parallel to the direction of the linear vibration force P, and is substantially equal to the angle α with respect to the horizontal line to which the vibration mechanism 73 is attached. That is, when there is no load, the drum vibrates at substantially uniform amplitude and vibration angle at each point of the peripheral wall portion of the drum main body 71. It is conceivable to perform a circulating motion as shown by an arrow R in FIG. Therefore, in practice, it is difficult to perform the circulating motion as shown in the figure, and the oscillating speed is small because the amplitude is small, and the fluidity is inferior to that of the conventional example. This is because the casting M to be sanded is driven to vibrate together with the drum main body 71 in the direction of the vibration P when no load is applied.
Although the vibration direction as shown by ₁ substantially equal to the direction of P, therefore it is substantially parallel to the direction of P as described above in which from the angular position a ₂ in the no-load of 30 degrees in the counterclockwise direction, At this point, the angle of this vibration with respect to the inner peripheral wall surface of the drum body 71 is substantially parallel, and therefore, as is clear from the vibration theory, the acceleration is 1 g or less in the vertical direction of this surface, and the body does not jump. Therefore, there is no transfer effect by vibration. In addition, counterclockwise from this,
In larger angular position, for example the inner wall surface of the transfer action drum body 71 by vibration on the inner wall surface of the drum body 71 relative to the at point a _3, although the transfer of the counterclockwise direction is desired, it is clockwise, which in Lowest point a
₁ , the casting force M and the separated sand S in the drum main body press against the inner peripheral wall surface of the drum main body 71 as if it were an integral rigid body. It vibrates integrally like. Therefore, the amplitude at each point by the fixed exciter 73 is naturally small, and thus fluidization is prevented as described above.

Further, in the conventional example, for example, 60 Hz
894r. p. m. 894r. p. m. In the technical field of so-called vibration, it belongs to the very low frequency, which causes the neighboring building where this vibrating drum is located to be in resonance with the vibration by this very low frequency, and a part of the building, for example, a shoji or door, etc. Is vibrating rattling. Therefore, residents living near the factory where the vibrating drum is provided suffer from vibration pollution.

In view of the above-mentioned problem, the applicant has found that even when the rotational driving force is the same, the amplitude of the amplitude when the load is changed from no load to the load state is small, and the material to be treated is, for example, sand. When castings to be separated are introduced, they are supported on the ground by anti-vibration springs for the purpose of providing a vibrating drum that promotes fluidization against this and also prevents ultra-low frequency pollution to nearby buildings. A circular vibrating force generator that generates a circular vibrating force by rotation of an unbalanced weight is provided on the peripheral wall portion of the drum body, and the center of the circular vibrating force is perpendicular to the axis of the drum main body. The vibrating drum was characterized in that an angle formed by a straight line connected to the horizontal line with respect to the horizontal line was 0 to 90 degrees above the axis.

FIGS. 16 to 20 show a specific example of the above proposal. In the figures, the vibrating drum is indicated as 101 as a whole.
A vibrator 103 is provided on one side of the peripheral wall of the drum main body 102. The drum body 102 includes a support 104a,
Vibration-proof springs 106a, 106b, 107a, and 107b disposed on 104b, 105a, and 105b are tiltably tilted downward several degrees in the figure to be vibrated.
A supply port 108 for supplying a casting to be sanded is formed at the left end of the drum main body 102 in FIG.
At the right end, there is provided a discharge port 109 for discharging the sanded casting.

The drum main body 102 is reinforced at its peripheral wall by a rib 110, and the right end is a lid 111.
Is partially closed.

Next, the details of the vibration exciter 103 will be described with particular reference to FIGS.

The vibrator 103 is a circular vibrator that generates a circular vibration force. An electric motor 124 is fixed on a frame 123 disposed on the side of the drum main body 102, and this is a driving source. . A first link 125 connected to a universal joint mechanism at both ends is connected to the rotating shaft 124a of the electric motor 124. That is, the electric motor 1
24 is a universal joint 126
The left end of the first link 125 is connected to the first support shaft 129 via a universal joint 126b. The first support shaft 129 is fitted to an inner race of a pair of bearings 128a and 128b fixed on both sides of a mounting plate 127 attached to the drum main body 102, and has one end substantially as shown in FIG. Semicircular unbalance weight 13
0a is fixed, and the other end of the first support shaft 129 has the same shape as the unbalance weight 130a.
The weight 130b is fixed.

The first support shaft 129 is further connected to a second link 131 and a second support shaft 135 via universal joints 132a and 132b.
02 is fitted through the inner race of a pair of bearings 134a, 134b provided on both sides of a mounting plate 133 mounted on the peripheral wall portion of the outer peripheral portion 02. The unbalanced weights 130a, 130b are provided at both ends. Unbalanced weights 136a and 136b having the same shape as the above are fixed.

The center of the circular excitation force, that is, the drive shaft 125
The angle β of the straight line LL that is perpendicular to the axis C of the drum main body 102 and the axis C of the drum body 102 is set to 25 degrees with respect to the horizontal line HH. The height position of the gantry 123 and the shape of the mounting plate 127 are set so as to obtain this angle of 25 degrees. Further, according to this specific example, the rotation direction of the electric motor 124 that drives the drive shaft 125 is driven to rotate clockwise in FIG.

The vibrator 103 is constructed as described above, but a pair of inspection windows 121 are further provided on the upper wall of the drum body 102.
a and 121b are provided, and an arc-shaped dam plate 122 is fixed to a part of the inner wall near the discharge port 109 of the drum main body 102 as shown in FIG. The vibration drum main body 101 is configured as described above. Next, this operation will be described.

Although not shown, it is assumed that a casting to be sanded is fed from the material supply port 108. Electric motor 124
Is driven, the rotational force of the rotating shaft 124a is changed to the universal joints 126a, 126b, the first link 125,
Via a pair of unbalance weights 130a, 13
0b, and the first support shaft 129 fixing the unbalance weights 130a and 130b.
Unbalance weights 136a, 136b fixed to both ends of a second support shaft 135 connected via universal joints 132a, 132b and a second link 131
Are similarly driven to rotate. The rotation of the unbalance weights 130a, 130b, 134a, and 134b generates a centrifugal force, that is, a circular excitation force around the rotation axis, that is, the axis of the support shafts 129 and 135, which will be described later. Drum body 1 by exciting force in various modes
02 vibrates. The rotating shaft 124a of the electric motor 124 is connected to the unbalance weights 130a and 130b via universal joints 126a and 126b, and the first support shaft 129 is connected to the universal joint 13
Unbalance weight 136 via 2a and 132b
Since the vibrations of the drum main body 102 are hardly transmitted to the electric motor 124 since the motors 124 and 136b are coupled to each other, the rotational driving can be stably continued.

FIG. 20 shows the relationship between the axis C of the drum body 102, the center of gravity G of the entire drum, and the center P of the above-described vibrating force of the vibrator 103. A circular exciting force F as shown in FIG. 20 is generated, and a rotational moment is generated around this and the center of gravity G,
In addition, the drum body 1 varies depending on the distance from the center P of the excitation force F.
02 is indicated by a circle as a line, and a vibration mode as shown is performed on this circumference. That is, on the peripheral wall portion of the drum body 102 closest to the vibrator 103, a ₁ , a ₂ ,
Performs elliptical vibration as shown by a ₃ and a ₄ .
The major axis and the minor axis are larger than the other peripheral wall portions, and the major axis is sequentially inclined in a counterclockwise direction from a substantially vertical direction. In the bottom wall of the drum body 102, b ₁ , b
_2, b ₃ and are subjected to linear vibration and elliptical vibration as shown by b ₄ is inclined so as to have a vibration transfer force in a counterclockwise direction in the tangential direction to the direction the drum inner wall surface of the major axis .

At points near the top of the vibrating drum body 102, as shown by d ₁ , d ₂ , d ₃ .
The elliptical vibration is performed, and the major axis and the minor axis become smaller sequentially, and the above-mentioned vibrations b ₂ , b ₃ , b ₄ , c ₁ , c ₂
.. Are elliptical vibrations rotating clockwise in FIG. The vibrations d ₁ , d ₂ , and d ₃ are also elliptical vibrations, and are vibrations that rotate clockwise, but the direction of the long axis is almost parallel to the tangent to each point on the peripheral wall surface of the drum main body 102, and The transfer force due to the vibration is such that the material does not rise to this point, but hardly. And FIG.
In, in the angular position of about 170 degrees when viewed from the vibration a ₁ relates axis C in the counter-clockwise direction, performing linear vibration as indicated by vibrations e. From this angular position, the elliptical vibration f
₁ , f ₂ , f ₃ , and f ₄ have their major axis and minor axis sequentially increasing, but rotate counterclockwise, and again become linear vibration b ₁ at the bottom of the vibrating drum body 102,
The elliptical vibration is performed again from this angular position in the counterclockwise direction as described above, but the rotation direction is clockwise.

In the above vibration modes, the origin of the X-Y orthogonal coordinates is the same as the center C '(axis C) of the drum cross-section circle, and the results of calculation by a computer when each dimension is as follows: It is.

Drum diameter D (CM) 120.0 Total weight W (Kg) 1970.0 Moment of inertia AI (KgSqCM) 8820000.0 around the total weight center 8820000.0 Total weight center position X coordinate XM (CM) 18.3 Total weight center Position Y coordinate YM (CM) 7.6 Exciting force position X coordinate S (CM) 92.4 Exciting force position Y coordinate SS (CM) 38.3 Frequency N (RPM) 900.0 Lower end amplitude AT (mm) 9.0 Exciting force F (Kg) 5664.7

Casting M supplied from the material supply port 108
Is tilted downward by about 2 to 3 degrees in FIG. 16 while receiving the above-described vibration from the inner wall portion of the drum main body 102, and thus is transported to the right. As described above, the casting M is subjected to the force rising in the counterclockwise direction in FIG. 20 along the inner peripheral wall surface of the drum main body 102, and when it rises to a certain level, the gravity is increased and the upper surface of the upper layer of the casting M is lowered. While moving along the inner peripheral wall surface and again performing the movement shown by the trajectory Q receiving the ascending force, it is transferred to the right in FIG. It is released from the outlet 109 by receiving the cooling and cooling action. As shown in FIG. 18, an arc-shaped weir plate 122 is provided near the outlet 109 along the inner peripheral wall surface. So
The above-described stirring force can be sufficiently received to separate the sand, and the sand can be discharged to the outside through the discharge port 109. If there is no weir plate 122 and the filling rate of the casting M to be sanded into the drum body 102 is small, it will be discharged to the outside from the discharge port 109 without receiving a sufficient stirring force. Therefore, the effect of the weir plate 122 has a great effect when the filling rate of the casting in the drum main body 102 is reduced.

As described above, the casting M to be sanded is put into the vibrating drum body 102 and subjected to the stirring action. The vibrations b ₁ , b ₂ , b ₃ , b ₄ , c ₁ , c ₂・
.. Represents a state in which the casting M to be sanded is not put into the drum main body 102, that is, a vibration state in a no-load state. In the case where the casting M to be cast is charged and the circulation motion is performed as shown in the figure, the set of the amplitude is almost smaller than in the conventional case, and the above-mentioned b ₁ , b ₂ , b
_There is almost no change in the vibration mode of ₃ ... And the amplitude is only slightly smaller. Therefore, the casting M receives a transfer force as described below.

[0028] While in the lowest portion of the drum body 102 is performed a linear vibration b _1, at this point the main body 1
It is a straight line in the upper right direction with respect to the tangent at the point of the peripheral wall surface 02. As is well known, such a linear vibration receives a large transfer force. Accordingly, the casting M to be sanded is subjected to a large transfer force and is transferred counterclockwise in the drawing. Further, in the counterclockwise direction, b ₂ , b ₃ , b ₄
In, the amplitude in the long axis and the short axis increases. Since the direction of the major axis has a vibration angle that receives the transfer force due to vibration with respect to the tangential direction at one point of the peripheral wall surface of the drum body,
At these points as well, the casting M and the sand S receive a large transfer force, and receive a force transferred in the counterclockwise direction to rise. Further, in c ₁ , c ₂ , and c ₃ , the direction of the long axis has only a slight vibration angle with respect to the tangent at each point on the peripheral wall surface, so that the transfer speed due to the vibration force along that surface is Although it is very small, again, unlike the conventional example, it slightly applies a transfer force in the counterclockwise direction on the peripheral wall surface of the drum body 2. And at the position rotated about 90 degrees counterclockwise from the bottom, it vibrates at a ₁ , but at this point the long axis is almost parallel to the tangent at one point on the peripheral wall, and No transfer force. Vibration a ₂ , a at the angular position further advanced in the counterclockwise direction
_3, the vibration angle is reversed with respect to the tangential direction of the major axis in a ₄ are for each point of the peripheral wall, the vibration c ₁ above, c _2, c ₃ ·
And the transfer direction is reversed. That is, since the casting is transferred in the clockwise direction, if the casting is transferred by such vibration force (actually, the casting falls by gravity), the above-mentioned c is used.
_The transfer speed due to the vibration of ₁ , c ₂ and c ₃ will be reduced.

As described above, the casting M to be separated supplied at the filling rate as shown in FIG. 20 is moved along the axis C of the vibrating drum body 102 while receiving the stirring force indicated by the arrow Q. 16 is transferred to the right in FIG. 16, but in a three-dimensional manner, the sand is sufficiently sanded while receiving a spiral stirring force, and as the moisture from the casting evaporates, the latent heat is exposed. , And is efficiently cooled and discharged outward from the discharge port of the drum body.

In this embodiment, the mode of the elliptical vibration from the bottom of the drum body to the position rotated 90 degrees counterclockwise changes as described above. Since this is the direction in which the vibration transfer force is received, and the rotational direction of the elliptical vibration is clockwise, it receives a larger transfer force, and therefore receives the circulation operation efficiently. Further, as described above, according to the present embodiment, the vibration at each point of the peripheral wall portion of the vibration drum body 102 in the no-load state is changed to the load state, that is, in the state where the casting M to be sanded is supplied. However, the amplitude, that is, the amplitude of the major axis and the minor axis of the elliptical vibration hardly changes, and therefore, it can be considered that a vibration force is given to the casting to be sanded in the vibration mode as shown in FIG. . It should be noted that there is little settling of the elliptical vibration c ₁ , c
_{In 2} , c ₃ and a ₄ , the vibration angle of the long axis is very small, but the amplitude in the short axis direction is sufficiently large, so that a large acceleration is applied in this direction, and this is 1 G or more. Then, naturally, the casting M to be sanded more efficiently receives a jumping force in the drum body by receiving a jumping force in a direction perpendicular to a tangent line at each point on the inner peripheral wall surface. In the conventional example shown in FIG.
02, a linear vibration force is applied to the peripheral wall portion. In this peripheral wall portion, the linear vibration in the above-described mode is performed. At a counterclockwise angular position of about 45 degrees from the bottom, as well as small in the direction of transport, the straight oscillation angle is reversed, thus providing a force to transfer the casting clockwise at this point. Therefore, the transfer force is applied at the bottommost portion in the counterclockwise direction. However, the casting at this point and the casting at about 45 degrees press against each other, resulting in a pressing force against the peripheral wall surface of the drum body. Therefore, as described above, with respect to the net mass of the drum main body, it becomes as if it vibrates integrally as a rigid body, the effective mass increases, and even if the magnitude of the linear vibration force is the same, there is no load and no load. Then, the amplitude changes greatly. Therefore, in order to obtain the vibration as shown in FIG. 13 under the load, the magnitude of the linear excitation force must be further increased. However, in this embodiment, not only does the amplitude hardly change, but also the driving force can be reduced.

Further, according to this embodiment, the sound level of the very low frequency (900 rpm) noise emitted from the vibration drum 101 is compared with that of the prior art vibration drum to which a linear excitation force is applied as shown in FIG. Then, an experimental result as shown in FIG. 21 is obtained. That is, the relationship between each point up to 100 m from the center of the vibration drum 101 and the ultra-low frequency noise level dB at that point changes as shown in FIG. In each case, the noise is reduced linearly, but the noise of the related art is about 6 dB higher. Therefore, since this is the degree in dB, the influence of the ultra-low frequency noise on each building at 100 m can be made much smaller. Obviously, as described above, the conventional vibrating drum performs a linear vibration, and when viewed from a distance as a projection surface, the amplitude of the linear vibration is large, thus causing each damage with ultra-low frequency noise. According to the present embodiment, as shown in FIG. 20, each peripheral wall portion of the vibration drum main body 102 performs an elliptical vibration, and the amplitude in the short axis direction is a noise source with respect to a point at a certain distance from the axis C. Therefore, it is expected that the noise level will obviously be reduced. This is made clear by FIG.

As described above, according to the vibrating drum 101 proposed by the present applicant, the disadvantages of the prior art can be solved, and the above-described great effect can be obtained. The reason for this great effect is shown in FIG.
As shown in the figure, the distribution of the elliptical vibration in the peripheral wall portion of the drum main body, particularly the amplitude of the elliptical vibration in the short axis direction greatly contributes. In order to further increase the amplitude in the short axis direction, the unbalanced weight 130 of the circular shaker 103 is required.
a, 130b, 136a, and 136b may be increased in mass.
Load increases.

[0033]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to eliminate the drawbacks of the conventional vibrating drum and to further improve the vibrating drum proposed by the present applicant. .

[0034]

SUMMARY OF THE INVENTION The object of the present invention is to mount a vibrating force generator, which generates a vibrating force by rotation of an unbalanced weight, on a peripheral wall of a drum body supported on the ground by a vibration-proof spring. In the vibrating drum, the unbalanced weight has a first unbalanced weight having a small distance r ₁ × mass m ₁ from the first rotation center to the center of gravity, and a distance r ₂ × mass from the second rotation center to the center of gravity. m
_{2 comprises a} large second unbalanced weight, and the first and second weights
A vibrating drum is characterized in that the unbalanced weights are each rotated at a constant speed around the rotation center in the opposite direction.

[0035]

The first unbalanced weight and the second unbalanced weight rotate in opposite directions at the same speed to generate an elliptical vibration force. For example, when this vibrator is mounted at the position of the peripheral wall of the drum main body in the vibration drum proposed by the present applicant, the vibration mode as shown in FIG. 20 and the conventional vibration mode as shown in FIG. It is presumed to indicate a vibration mode between the vibration mode of the main body of the vibration drum and the vibration mode. The vibration drum proposed by the applicant of the present invention solves the drawback of the conventional vibration drum shown in FIG. 15, and the vibration on the peripheral wall of the drum body is a linear vibration as shown in FIG. However, if this is a vibration mode as shown by a ₁ and a ₂ in FIG. 15 with respect to the battle direction of the peripheral wall surface, it is clear that it has a large transfer force. It is also possible to generate more than in the mode, and it is possible to increase the transfer force in the clockwise or counterclockwise direction from the bottom wall of the drum body. As is clear from the vibration modes of FIGS. 15 and 20, the desired vibration force components in the major axis direction and the minor axis direction of the elliptical vibration force of the main elliptical vibration force generator are equal to those of the first and second unbalanced weights. r ₁ × m
By easily changing the relative size between ₁ and r ₂ × m ₂ , it is possible to easily obtain the amplitude in the short axis of the elliptical vibration mode of the peripheral wall of the drum body as shown in FIG. (C ₂₎ so that the amplitude in the short axis direction of the elliptical vibration is perpendicular to the tangential direction of the peripheral wall (where the casting and sand rise) of the drum body as described above. , C ₃ , a ′ ₁ ), and if a vibrator is attached, the effect of stirring the mold and sand in the drum body can be increased.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vibration drum according to an embodiment of the present invention will be described below with reference to FIGS.

FIGS. 1 to 8 show a vibrating drum according to a first embodiment of the present invention. In the drawings, the vibrating drum is indicated as a whole by 30 and is provided on one side of a peripheral wall of a drum main body 31. An excitation source 38 is provided. Further, the drum main body 31 is supported so as to be capable of vibrating while being inclined several degrees downward to the right in the drawing by vibration-proof springs 36a, 36b, 37a, and 37b disposed on the columns 34a, 34b, 35a, and 35b. In FIG. 1 of the drum main body 31, a supply port 32 for supplying a casting to be sanded is formed at a left end, and a discharge port 33 for discharging the casting and sand separated therefrom is formed at a right end. Is provided. In the drum body 31, a punch metal 60 is stretched from a certain area, and sand separated from the casting is
0, falls into the lower space 33B, and is discharged to the outside from below the punch metal 60.
From the upper space 33A.

The drum body 31 is reinforced at its peripheral wall by a rib r, and its right end is closed by a lid 49.

Next, the details of the vibration source 38 will be described with reference to FIG.
Referring to FIG. 7 to FIG. 7, it is composed of a pair of vibration motors 12A and 12B,
a and 13b have large and small unbalanced weights 14a, 14a, 14b, which will be described in detail after having a substantially semicircular shape.
14b is fixed. Gears 19a, 19b having the same number of teeth and having the same diameter are fixed to the one end, and gears 20a, 20b having the same number of teeth having the same diameter are arranged inside the gears. This is supported by the shafts 21a and 21b, and the inner races of the bearings 23a and 23b are fitted. The teeth as the gears 20a and 20b are formed on the outer race side, and the inner races of the bearings 23a and 23b are The shafts 21a and 21b to be fitted and fixed are supported by the bearing member 18 as clearly shown in FIG. Power cords 15a and 15b are connected to the commercial power supply (not shown) from the vibration motors 12A and 12B. Unbalance weights 14a, 14
a, 14b, 14b so as to cover them.
6a, 16b, and 16b are attached, and one of the covers 16a and 16b is rotatably penetrated therethrough.
3a and 13b are inserted. The entire excitation source 38 configured as described above is fixed on the seat plate 40. Seat plate 4
Reference numeral 0 indicates that the peripheral wall surface of the drum main body 31 is fixed on a fixed reinforcing rib r.

The unbalance weight 14 of this embodiment
a, 14b is such as has a shape as shown by A in FIG. 6, the rotary shaft 13a, from 13b the axis, the distance r ₁ and r ₂ to the respective center of gravity G _1, G ₂ illustrates If the masses are m ₁ and m ₂ , respectively, m ₁ × r ₁ is configured to be smaller than m ₂ × r ₂ . Accordingly, the centrifugal force F ₁ generated by each of the unbalance weights 14 a becomes m ₁ around the rotation shafts 13 a and 13 b in the opposite direction at a constant speed.
× r ₁ × ω ² (ω = angular velocity) and the magnitude of the centrifugal force F ₂ generated by the larger unbalanced weight 14b are m ₂ × r ₂ ×
omega ² become clearly F ₁ is configured to be smaller than F _2. In FIG. 2, the angle of the straight line V with respect to the horizontal line is 4
5 degrees.

The embodiment of the present invention is configured as described above. Next, this operation will be described.

First, the operation of the vibration source 38 will be described.
Each of the unbalance weights 14a and 14b rotates in the rotation phase as shown in FIG. 6, but in the rotation phase indicated by A, the line connecting the respective centers of gravity G ₁ and G ₂ and the axis is directly below. Therefore, at this time, the centrifugal force F generated by the unbalance weights 14a and 14b
_1, the direction of F ₂ is oriented directly below, as shown.
From now on, it will rotate at a constant speed of angular velocity ω.
When rotated by degrees, the rotation phase becomes a rotation indicated by B, and F ₁ and F ₂ generated by the respective unbalanced weights are in opposite directions in the horizontal direction. Further rotation by 90 degrees, the centrifugal force F ₁ , F
₂ both point directly above. When rotated further by 90 degrees, they turn in opposite directions in the horizontal direction. From the above, in the phase A, each unbalanced weight 14a, 1
The resultant force of the centrifugal force of 4b is F ₁ + F ₂ in the vertical direction, and F ₂ −F in the horizontal direction in the phase of B.
₁ and 0 in the vertical direction. In the phase C, the resultant force is F ₂ + F _{1 in} the vertical direction, and is 0 in the horizontal direction. Further, in the rotation phase of D, it is 0 in the vertical direction, but it is F ₂ −F ₁ in the horizontal direction, which is opposite to the direction of the rotation transfer of B.

As can be inferred from the above, it is apparent that an elliptical vibration force is generated for the movable body on which such a vibration source 38 is mounted, but this will be further proved mathematically.

In FIG. 7, the point of attachment of the vibration source 38 to the movable body is denoted by O. The x-axis and the y-axis of rectangular coordinates are set with this as the origin. On the x-axis, O ₁ and O ₂ are set at equal distances in opposite directions from the origin O. This is Figure 2
Shafts 13a, 13b of the electric motors 12A, 12B in FIG.
Axis. Now, the rotating shafts 13a and 13b rotate in the opposite direction at a constant speed. If this angular speed is ω,
Assuming that the time when F ₁ and F ₂ are oriented in opposite directions on the x axis is the time start point, the position shown in FIG. 7 is taken after t seconds, and the respective centrifugal forces F ₁ and F ₂ are in the illustrated directions. Is facing.

That is, the force component at this time in the y-axis direction and the force component in the x-axis are respectively y = F ₁
sin ωt + F ₂ sin ωt = (F ₁ + F ₂ )
sin ωt, x = F ₁ cos ωt−F ₂ cos
ωt = (F ₁ −F ₂ ) cos ωt, where F ₁ + F ₂ = A and F ₁ −F ₂ = B in the above equation,
y = A sin ωt and x = B cos ωt.
From this, y ² = A ² (1−cos ωt ² ). Therefore, a relationship of 1 = y ² / A ² + x ² / B ² is obtained. That is, this is the equation of the ellipse. Therefore, it is proved that an elliptical vibration force is generated from the vibration source 38 having the structure shown in FIG.

Power cord 1 for vibration motors 12A and 12B
When 5a and 15b are connected to an AC power source, the vibration motor 12
The rotating shafts 13a and 13b of A and 12B rotate, and the gears 19a and 19b fixed at one end also rotate. The small-diameter gears 21a and 21b meshing with this also rotate, but since they are meshing and have the same number of teeth and the same diameter, the union weights 14a and 14a of the vibration motors 12A and 12B are combined by these gears. , 14b, 14b rotate synchronously at the same speed in opposite directions. That is, they are driven synchronously by forced synchronization. Accordingly, an elliptical vibration force is generated as described above, and this is transmitted to the drum main body 31. Therefore, it vibrates in an intermediate mode between the mode shown in FIG. 15 and the mode shown in FIG. The casting M in the drum main body 31 circulates as indicated by the arrow in FIG. 2, and the sand S is dropped from the casting under the vibration force. While receiving such a separating action, the sand S is transported rightward in FIG.
In 3, the casting M from which the sand is separated from the lower space 33 </ b> B and the sand is separated is discharged from the upper space 33 </ b> A to the outside.

According to the present embodiment, the vibration motors 12A, 12A
B is forcibly operated synchronously by the gears 19a, 19b, 20a, 20b, so that the vibration motors 12A, 12B are disposed at positions deviated from the center of gravity as shown in the figure, but the synchronous operation is surely performed. Therefore, the elliptical vibration force can be stably applied to the drum main body 31. Therefore, a stable sand separating action can be performed. In addition, the effects that the vibrating drum generally has can be directly obtained.
That is, not only can sand removal be surely performed by the circulating motion of the sand S and the casting M as shown in FIG. 2, but also the aging of the casting sand due to the difference in the circulation speed between the casting M and the sand S is prevented. In addition, the casting is protected by the sand S and is prevented from being damaged by the impact of the peripheral wall of the drum body 31.

Further, since a pair of vibration motors 12A and 12B are simply connected by gears to perform forced synchronization, they are simply mounted on the drum main body 31, so that the entire structure of the vibration source is simpler than the conventional example. is there. Therefore, the cost can be significantly reduced.

In the case of the present embodiment, the vibration source 38 for generating the above-mentioned elliptical vibration force is provided on the peripheral wall of the vibration drum main body.
Therefore, it is presumed that a vibration mode between the vibration mode of the conventional vibration drum shown in FIG. 15 and the vibration mode of the vibration drum previously proposed by the present applicant shown in FIG. 20 is performed. That is, since it is an elliptical vibration force, it has a major axis and a minor axis, but generates a vibration mode in which the direction component of the major axis is close to the vibration mode shown in FIG. ). In the vibration on the short axis, the circular exciting force in FIG. 20 gives a vibration component in a direction perpendicular to the straight line LL, and a component in a direction perpendicular to this, that is, LL
It is apparent that the elliptical vibration component as shown in FIG. In the above-described elliptical excitation force, the direction of the long axis is a component perpendicular to the straight line LL in FIG. 20, and the component parallel to the straight line LL is a vibration force component in the short axis direction in FIG. It is clear that this gives an elliptical vibration mode as in. Due to such a vibration mode, the stirring operation shown in FIG. 20 is performed, the stirring is performed more efficiently than in the conventional case, the cooling is performed, and the mold is separated. The magnitudes of the components in the major axis direction and the minor axis direction of the elliptical vibration force can be easily changed by changing the MR (mass × distance between rotation center and center of gravity) of the first and second unbalanced weights. Obviously, it can be adjusted to For example, when the magnitude of the MR of one of the first unbalanced weights is increased, the magnitude of the short-axis component of the elliptical vibration can be increased.

FIG. 8 shows a result obtained by calculating the vibration mode of the present invention by a computer. Although the dimensions of the drum main body are slightly different from those in the case of FIG. 20 and the mounting angle β ′ (45 degrees) of the vibration source F ′ to the drum main body is different, the expected vibration mode is obtained.

Near the bottom of the drum body 31, g ₁ , g
_2, is substantially linear vibration as shown by g _3, it has an angle (about 45 degrees) to respect the tangential direction of the inner peripheral surface of the drum body 31 having a transfer force due to vibration. Also, in the figure, g at counterclockwise angles of about 45 °, 60 °, and 75 °
₄ , g ₅ and g ₆ are obtained, but the component of the elliptical vibration in the short axis direction is large and the component in the direction perpendicular to the wall surface of the drum body 31 is large.
As in the case of 0, a force for jumping (1 g or more) from the wall surface in the radial direction is received, and a large stirring speed can be given as in the invention previously proposed by the present applicant. Sand S
The same applies to the separation operation between the steel and the casting M and the cooling operation.

FIGS. 8 and 9 show a vibration drum 50 according to a second embodiment of the present invention. In this embodiment, parts corresponding to those in the above embodiment are denoted by the same reference numerals. Also in this embodiment, a material supply port 52 is formed at one end of the drum main body 51, and a material discharge port 53 is formed at the other end. Posts 54a, 54b, 55a, 55b
It is tilted downward several degrees toward the material discharge port 53 via anti-vibration springs 56a, 56b, 57a, and 57b, and is supported so as to be able to vibrate. A vibration source 58 is attached to one side of the drum main body 51. The vibration source 58 has the same structure as that of the above-described embodiment, but is different from the vibration motor 12 of the second embodiment.
The rotating shafts 13a and 13b of A and 12B are mounted so as to extend in a direction substantially perpendicular to the axis C 'of the drum main body 51. The linear vibration force V 'generated by the vibration motors 12A and 12B is mounted so as to pass through the axis C' of the drum main body 51. Therefore, the synchronizing force due to the vibration larger than that of the first embodiment works, and the vibration motor 12
The strength of the gear for forcibly synchronizing A and 12B can be made smaller. Other operations and effects are the same as those of the above-described embodiment.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited thereto, and various modifications can be made based on the technical concept of the present invention.

For example, in the above embodiment, the vibration motor 12
A and 12B are used as a pair, and gears having the same diameter and the same number of teeth are attached to the end of the rotating shaft, and by meshing them, the first and second unbalanced weights are synchronously moved in opposite directions. Instead of this, a rotating shaft extending substantially parallel to the axis of the vibrating drum main body is arranged as a pair close to the peripheral wall of the drum main body, and these are arranged according to their length. The motors are rotatably supported by a plurality of bearings fixed to the shaft, and each motor is independently coupled to the shaft end via a suitable coupling. By installing gears of the same number of teeth and engaging them, the above-mentioned independent rotational torques are not the same, and the loads of the first and second unbalanced weights are different, so that even if the torques are the same, Should be different, but reciprocal due to gear coupling of the same diameter and the same number Rotate at the same speed that direction. Therefore, the above-described elliptical vibration force can be generated. The magnitude of the elliptical vibration force can be increased by attaching a plurality of unbalance weights having the same shape as the above embodiment to the two rotating shafts. Also, by appropriately selecting the number of these large and small unbalanced weights, the ratio of the long axis to the short axis can be easily adjusted.

In the above embodiment, the drum is attached at a position approximately 45 degrees clockwise above the horizontal line passing through the axis at the peripheral wall of the drum main body. And about 4 above the horizon
You may make it attach to a position of 5 degrees. In this case, of course, the flow of the casting to be unmolded in the drum body is a flow which rises clockwise in the opposite direction to that shown in the figure.

[0056]

As described above, the vibrating drum of the present invention has a great advantage as compared with the other types of drums as well as the conventional vibrating drum, and also has a vibrating mechanism which is different from the conventional vibrating drum. Not only greatly reduces the cost, but also reduces the amplitude of each part when the load is changed from the no-load state to the load state. The magnitude of the short axis vibration component of the elliptical vibration, which is a major factor for obtaining such an effect, can be easily adjusted.

[Brief description of the drawings]

FIG. 1 is a side view of a vibration drum according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line [2]-[2] in FIG.

FIG. 3 is a plan view of a main part of the vibration drum.

FIG. 4 is a partially broken front view of the main part.

FIG. 5 is a sectional view taken along line [5]-[5] in FIG.

FIG. 6 is a simplified front view of first and second unbalanced weights in each rotation phase for explaining the operation of the embodiment.

FIG. 7 is a schematic diagram for mathematically proving the operation of the embodiment.

FIG. 8 is a schematic front view of the vibrating drum for explaining the operation of the embodiment.

FIG. 9 is a partially broken side view of a vibration drum according to a second embodiment of the present invention.

FIG. 10 shows [10]-[1] in FIG. 9 of the vibration drum.
0] is a sectional view taken along the line.

FIG. 11 is a side view of a conventional vibration drum.

12 is a sectional view taken along the line [12]-[12] in FIG.

FIG. 13 is a sectional view of another conventional vibration drum.

FIG. 14 is a partially broken front view of the vibrator in the conventional example.

FIG. 15 is a schematic diagram for explaining the operation of the conventional example.

FIG. 16 is a side view of a vibrating drum proposed by the applicant.

FIG. 17 is a plan view of the same.

FIG. 18 is a front view of the same.

19 is an enlarged sectional view taken along the line [19]-[19] in FIG. 17;

FIG. 20 is a schematic diagram for explaining the operation of the vibration drum.

FIG. 21 is a graph showing a comparison of ultra-low frequency noise between the vibration drum and a conventional vibration drum.

[Explanation of symbols]

 14a Unbalanced weight 14b Unbalanced weight 19a Gear 19b Gear 20a Gear 20b Gear 30 Vibration drum 38 Vibration source 50 Vibration drum 58 Vibration source

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-150768 (JP, A) JP-A-4-210864 (JP, A) JP-A-3-193262 (JP, A) JP-A-3-31026 189067 (JP, A) JP-A-53-28860 (JP, A) JP-A-4-220156 (JP, A) JP-A-4-453 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B22D 29/00 B06B 1/16

Claims (4)

(57) [Claims] 1. A vibrating drum having a vibrating force generator for generating a vibrating force by rotation of an unbalanced weight attached to a peripheral wall of a drum body supported on the ground by a vibration-proof spring. The weight is a first unbalanced weight having a small distance r ₁ × mass m ₁ from the first rotation center to the center of gravity, and a second unbalance having a large distance r ₂ × mass m ₂ from the second rotation center to the center of gravity. A vibrating drum, wherein the first and second unbalanced weights are respectively rotated at equal speeds around the respective rotation centers in opposite directions. 2. A straight line perpendicular to a straight line connecting the first center of rotation and the second center of rotation passes through the axis of the drum main body, and an angle formed by the straight line with respect to a horizontal line is the axis center. The vibration drum according to claim 1, wherein the vibration drum is mounted so as to form an angle of 0 to 90 degrees at an upper position. 3. The vibrating drum according to claim 2, wherein said angle is about 45 degrees. 4. The vibrating drum according to claim 1, wherein a casting to be sanded is supplied as a material into the drum body.