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Claims  |
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What is claimed is:
1. A vibratory drum machine for treating articles comprising:
A. a cylindrical drum body supported resiliently by springs;
B. means for generating an elliptical vibratory force as a resultant force; and
C. means attaching said generating means directly to the peripheral wall of said cylindrical drum body above the horizontal line passing perpendicularly through the central axis of said cylindrical drum body, said generating means comprising
electric motors, a first unbalance weight, a second unbalance weight and gear mechanism for transmitting the rotational forces of said electric motors to said first and second unbalance weights at the same speed in the opposite directions, m.times.r
(mass.times.distance between a rotational center and gravity center) of said first unbalance weight being smaller than that of said second unbalance weight.
2. A vibratory drum machine for separating sands from cast components comprising:
A. a cylindrical drum body supported resiliently by springs, said cylindrical drum body having a peripheral wall defining an inner cylindrical wall surface,
B. means for generating a circular vibratory force as a resultant force; and
C. means attaching said generating means directly to the peripheral wall of said cylindrical drum body on or above the horizontal line passing perpendicularly through the central axis of said cylindrical drum body, said cylindrical drum body
having further an inlet at its one end portion and an outlet at its other end portion, said cast components being supplied through said inlet into said cylindrical drum body and being discharged through said outlet from said cylindrical drum body,
wherein the center of gravity G of said vibratory drum machine is spaced away from the central axis of said cylindrical drum body and the center P of said means for generating a circular vibratory force is located outwardly of said peripheral wall and
spaced away from said inner cylindrical wall surface so that elliptical vibrations of said inner cylindrical surface wall are effected in such a manner that directions of the longer axis of the elliptical vibrations change gradually and continuously
along said inner cylindrical wall surface and said cast components move upward adjacent said inner cylindrical wall surface to a certain level and then circulate downward along a path spaced inwardly from said inner cylindrical wall surface.
3. A vibratory drum machine according to claim 2, in which said generating means comprises a vibratory electric motor in which unbalance weights are fixed to both ends of a rotary shaft.
4. A vibratory drum machine according to claim 2, in which a line connecting the center P of said means for generating said circular vibratory force with said central axis of the cylindrical drum body makes an angle of 20.degree. to 30.degree.
with said horizontal line.
5. A vibratory drum machine according to claim 2 in which said generating means comprises plural vibratory electric motors in which unbalance weights are fixed on both ends of rotary shafts, respectively, said vibratory electric motors being so
arranged eccentrically to the side of said inlet with respect to the gravity center of said cylindrical drum body that the amplitudes of the longer and shorter axes of said elliptic vibrations are larger at the inlet portion than at the outlet portion.
6. A vibratory drum machine according to claim 3 in which said vibratory electric motor is so arranged eccentrically to the side of said inlet with respect to the gravity center of said cylindrical drum body that the amplitudes of the longer and
shorter axis of said elliptic vibrations are larger at the inlet portion than at the outlet portion.
7. A vibratory drum machine for separating sands from cast components comprising:
A. a cylindrical drum body supported resiliently by springs, said cylindrical drum body having a peripheral wall defining an inner cylindrical wall surface;
B. means for generating an elliptical vibratory force as a resultant force; and
C. means attaching said generating means directly to the peripheral wall of said cylindrical drum body on or above the horizontal line passing perpendicularly through the central axis of said cylindrical drum body, said cylindrical drum body
having further an inlet at its one end portion and an outlet at its other end portion, said cast components being supplied through said inlet into said cylindrical drum body and being discharged through said outlet from said cylindrical drum body,
wherein the center of gravity G of said vibratory drum machine is spaced from the central axis of said cylindrical drum body and the center P of said means for generating an elliptic vibratory force is located outwardly of said peripheral wall and spaced
away from said inner cylindrical wall surface so that elliptical vibrations of said inner cylindrical wall surface are effected in such a manner that directions of the longer axis of the elliptical vibrations change gradually and continuously along said
inner cylindrical wall surface and said cast components move upward adjacent said inner cylindrical wall surface to a certain level and then circulate downward along a path spaced inwardly from said inner cylindrical wall surface.
8. A vibratory drum machine according to claim 7, in which said generating means comprises electric motors, a first unbalance weight, a second unbalance weight and gear mechanism for transmitting the rotational forces of said electric motors to
said first and second unbalance weights at the same speed in the opposite directions, m.times.r (mass.times.distance between a rotational center and gravity center) of said first unbalance weight being smaller than that of said second unbalance weight.
9. A vibratory drum machine according to claim 7, in which a line connecting the center of said elliptical vibratory force with said central axis of the cylindrical drum body makes an angle of 45.degree. with said horizontal line.
10. A vibratory drum machine for separating sands from cast components:
A. a cylindrical drum body supported resiliently by springs; said cylindrical drum body having a peripheral wall defining an inner cylindrical wall surface; and
B. a circular vibratory force generating source comprising an electric motor supported on the earth, bearing means supported on the peripheral wall of said cylindrical drum body, support axis means rotatably supported by said bearing means and
connected through universal joint means to a drive shaft of said electric motor, and unbalance weight means fixed to said support axis means, said cylindrical drum body having further an inlet at its one end portion and an outlet at its other end
portion, said cast components being supplied through said inlet into said cylindrical drum body and being discharged through said outlet from said cylindrical drum body, wherein the center of gravity G of said vibratory drum machine is spaced away from
the central axis of said cylindrical drum body and the center P of said means for generating a circular vibratory force is located outwardly of said peripheral wall and spaced away from the said inner cylindrical wall surface so that elliptical
vibrations of said inner cylindrical wall surface are effected in such a manner that directions of the longer axis of the elliptical vibrations change gradually and continuously along said inner cylindrical wall surface and said cast components move
upward adjacent said inner cylindrical wall surface to a certain level and then circulate downward along a path spaced inwardly from said inner cylindrical wall surface.
11. A vibratory drum machine according to claim 10 in which said unbalance weight means comprises a first unbalance weight means comprising a first unbalance weight and a second unbalance weight, m.times.r (mass.times.distance between a
rotational center and gravity center) of said first unbalance weight being smaller than that of said second unbalance weight being smaller than that of said second unbalance weight, said first unbalance weight being located at the side of said outlet
with respect to the gravity center of said cylindrical drum body and said second unbalance weight being located at the side of said inlet with respect to the gravity center of said cylindrical drum body, said bearing means comprising a first bearing
member and a second bearing member, said support axis, said universal joint means comprising a first universal joint member and a second universal joint member, said first universal joint member, said first support axis, said second universal joint
member and said second support axis being arranged and connected in alignment with each other, in the order of the direction from said outlet towards said inlet, said first and second support axis being supported rotatably by said first and second
bearing members, respectively, and said first and second unbalance weights being fixed to said first and second support axis respectively, so that the amplitudes of the longer and shorter axis of said elliptic vibrations are larger at the inlet portion
than at the outlet portion.
12. A vibratory drum machine for separating sands from cast components comprising:
A. a cylindrical drum body supported resiliently by springs;
B. means for generating a circular vibratory force.
C. means for attaching said means for generating directly to the peripheral wall of said cylindrical drum body on or above the horizontal line passing perpendicularly through the central axis of said cylindrical drum, and wherein said means for
generating comprises an electric motor supported on the earth, bearing means supported on the peripheral wall of said cylindrical drum body, support axis means rotatably supported by said bearing means and connected through universal joint means to a
drive shaft of said electric motor, and unbalance weight means fixed to said support axis means, said cylindrical drum body having further an inlet at its one end portion and has an outlet at its other end portion, said cast components being supplied
through said inlet into said cylindrical drum body and being discharged through said outlet from said cylindrical drum body, wherein the center of gravity G of said vibratory drum machine is distant from the axis of said cylindrical drum body and the
center P of said means for generating a circular vibratory force is distant from the peripheral wall of said cylindrical drum body, said peripheral wall defining an inner cylindrical wall surface, elliptical vibrations imparted to said inner wall surface
being effected in such a manner that directions of the longer axis of the elliptical vibrations change gradually and continuously along said inner cylindrical wall surface and said cast components move upward along said inner cylindrical wall surface to
a certain level and then circulate downward along a path spaced inward from said inner cylindrical wall surface.
13. A vibratory drum machine for treating articles comprising:
A. a cylindrical drum body supported resiliently by springs; and
B. a circular vibratory force generating source comprising an electric motor supported on the earth, bearing means supported on the peripheral wall of said cylindrical drum body, support axis means rotatably supported by said bearing means and
connected through universal joint means to a drive shaft of said electric motor, and unbalance weight means fixed to said support axis means, and wherein said cylindrical drum body has an inlet at its one end portion and has an outlet at its other end,
said articles being supplied through said inlet into said cylindrical drum body and being discharged through said outlet from said cylindrical drum body, and said unbalance weight means comprises a first unbalance weight and a second unbalance weight,
m.times.r (mass.times.distance between a rotational center and gravity center) of said first unbalance weight being smaller than that of said second unbalance weight, said first outlet with respect to the gravity center of said cylindrical drum body and
said second unbalance weight being located at the side of said inlet with respect to the gravity center of said cylindrical drum body, said bearing means comprises a first bearing member and a second bearing member, said support axis means comprises a
first support axis and a second support axis, said universal joint means comprises a first universal joint member and a second universal joint member, said first universal joint member, said first support axis, said second universal joint member and said
second support axis being arranged and connected in alignment with each other, in the order of the direction from said outlet towards said inlet, said first and second support axis being supported rotatably by said first and second bearing member,
respectively, and said first and second unbalance weights being fixed to said first and second support axis, respectively.
14. A vibratory drum machine for separating sands from cast components comprising:
A. a first cylindrical drum body supported resiliently by springs;
B. a second cylindrical drum body arranged adjacent to said first cylindrical drum body and supported resiliently by springs;
C. a first circular or elliptical vibratory force generating source fixed on the peripheral wall of said first cylindrical drum body on or above the horizontal line passing perpendicularly through the central axis of said first cylindrical drum
body;
D. a second circular or elliptical vibratory force generating source fixed on the peripheral wall of said second cylindrical drum body on or above the horizontal line passing perpendicularly through the central axis of said second cylindrical
drum body, and being synchronized with said first circular or elliptical vibratory force generating source by synchronizing means; and,
E. each said cylindrical drum body having further an inlet at its one end portion and an outlet at its other end portion, said cast components being supplied through said inlet into said cylindrical drum body and being discharged through said
outlet from said cylindrical drum body, wherein the center of gravity G of said vibratory drum machine is distant from the axis of said cylindrical drum body and the center P of said means for generating a vibratory force is distant from the peripheral
wall of said cylindrical drum body, said peripheral wall defining an inner cylindrical wall surface, elliptical vibrations imparted to said inner wall surface being effected in such a manner that directions of the longer axis of the elliptical vibrations
change gradually and continuously along said inner cylindrical wall surface and said cast components move upward along said inner cylindrical wall surface to a certain level and then circulate downward along a path spaced inward from said inner
cylindrical wall surface.
15. A vibratory drum machine according to claim 14 wherein the means for generating an elliptical vibratory force each comprise a first unbalance weight, a second unbalance weight and gear mechanism for transmitting the rotational forces of said
electric motor to said first and second unbalance weights at the same speed in the opposite directions, m.times.r (mass.times.distance between a rotational center and gravity center) of said first unbalance weight being smaller than that of said second
unbalance weight.
16. A vibratory drum machine according to claim 14 wherein the means for generating a circular vibratory force each comprise an electric motor supported on the earth, bearing means supported on the peripheral wall of said cylindrical drum body,
support axis means rotatably supported by said bearing means and connected through universal joint means to a drive shaft of said electric motor, and unbalance weight means fixed to said support axis means. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a vibratory drum machine used especially for cleaning and cooling cast components to which the molding sand still adheres.
2. Description of the Prior Art
In FIG. 1, the vibratory drum machine of the prior art for cleaning and cooling the cast components is shown in general at 10. A support member 15 is fixed through strengthening ribs 26 to a cylindrical drum body 11. A mounting frame 12 is
supported through springs 14 by the support member 15.
An inlet 25, into which the cast components to be cooled and cleaned are supplied, is formed at the left end portion of the cylindrical drum body 11 (FIG. 1). A discharge chute 24 is connected to the right end of the cylindrical drum body 11.
The cooled and cleaned cast components are discharged outwards through the discharge chute 24. The left end of the drum body 11 is covered with an end wall 22a and the right end thereof is partially covered with an end wall 22b.
The drum body 11 is resiliently supported on the earth E by coil springs 16a, 16b, 17a and 17b. A drive source 13 consisting of a pair of vibratory electric motors 19a and 19b is fixed on the mounting frame 12. The vibratory electric motors 19a
and 19b have well-known constructions. Nearly semi-circular unbalance weights 20a and 20b are fixed to rotary shafts 21a and 21b of the vibratory electric motors 19a and 19b. A reinforcing partition 23 is fixed to the center of the mounting frame 12.
The vibratory electric motors 19a and 19b are fixed in symmetry on the mounting frame 12 with respect to the reinforcing partition 23. The unbalance weights 20a and 20b are rotated in the opposite directions, and they are fixed to the rotary shafts 21a
and 21b in the same rotary phase. A dust collecting duct 18 is fixed on the upper wall portion of the drum body 11 and it communicates with an internal space 27 of the drum body 11. As described below, a dust generating in the cleaning and cooling
operation of the cast components M is guided outwards through the dust collecting duct 18. The entire vibratory drum machine 10 is so arranged as to be inclined towards the discharge chute 24 by a few degrees.
When the drive source 13 is excited, the vibratory electric motors 19a and 19b are rotated in synchronization with each other. The pair of the vibratory electric motors 19a and 19b are driven at a frequency which is near to a resonance
frequency. The resonance frequency is predetermined by a spring constant of the coil springs 14, and the masses of the entire drum body 11 and drive source 13. A linear vibratory force is generated in the direction along the coil springs 14. The
vibratory force is transmitted to the drum body 11 through the coil springs 14 and support member 15. Since the drum body 11 is resiliently supported by the coil springs 16a, 16b, 17a and 17b, the drum body 11 is vibrated in an oblique direction as
shown by a arrow A. Accordingly, the cast components M and sand S circulate as shown by the arrows in the internal space 27 of the drum body 11. The drum body 11 is inclined towards the discharge chute 24 by a few degrees. Accordingly, the cast
components M and sand S are moved to the discharge chute 24 together with the circulation as shown by arrows in FIG. 2. In such a motion, the cast components M and sand S are separated from each other and they are discharged outwards through the
discharge chute 24.
The vibratory drum machine 10 of the one prior art is so constructed as above described and operates in the above manner.
In a sand-separating machine of another prior art, a plate having plural slits is arranged and cast components to be cleaned and cooled are supplied onto the plate. It is vibrated in a linear direction. The sand separated from the cast
components is discharged downwards through the plural slits and the cast components are moved on the plate by the linear vibratory motion. However, in this type sand-separating machine for the cast components, the cast components often are damaged by
the shock. Further, some cast components freely can not move on the plate. Thus, some cast components are not be cleaned and cooled so much sufficiently according to their shape and the sands are not fallen from the cast components. On the other hand,
the vibratory drum machine 10 of the above one prior art can remove the above described defects of the sand-separating machine.
Further, the pair of the vibratory electric motors 19a and 19b does not always synchronize with each other. When they are not synchronized with each other, some irregular vibratory force is imparted to the drum body 11. In that case, the above
described operations are not effected and so the sands are not freely separated from the cast components. Further, the vibratory drum machine 10 of the one prior art has the same defect as the sand-separating machine as above described. For example,
the cast components M sometimes are damaged on the internal wall of the drum body 11. To cope with this defect, the mounting position of the vibratory electric motors 19a and 19b to the drum body 11 and the arrangements of the coil springs 14 should be
strictly designed so that the vibratory electric motors 19a and 19b can be rotated in synchronization with each other. Accordingly, the vibratory drum machine 10 of the one prior art as shown in FIG. 1 and FIG. 2 is much expensive and further the
resonant condition can not be often obtained according to the sum weight of the supplied cast components M and sand S and their mass distribution. Accordingly, the synchronization of the rotation can not be often obtained.
In a sand-separating machine of a further type, a drum is rotated at a predetermined speed in a predetermined direction. It is so called "rotary drum". The cast components are brought up by engagement with members fixed on the internal wall of
the drum and they are dropped out at some height. Accordingly, the cast components are often damaged on shock to the inside wall of the drum. Further, since contact time of the cast components with inside wall of the drum is long, the sand is often
aged and also adding agent is often aged. Further, when the cast components are fallen onto the bottom portion of the drum, periodical noises are made. The vibratory drum machine of the one prior art is superior to this type sand-separating machine in
the above defects. However, there are some points to be resolved as above described.
FIG. 3 and FIG. 4 show a vibratory drum machine of another type. Parts in FIG. 3 which correspond to those in FIG. 1 and FIG. 2, are denoted by the same reference numerals, the detailed description of which will be omitted. In this example, a
vibratory force generating mechanism 13' for generating a linear vibratory force is mounted on the peripheral wall of the drum body 11. It consists of a pair of vibratory electric motors 22A and 22B. They are fixed on a mounting member 35. Gears 29a
and 29b of the same diameter and the number of teeth are fixed on one end portion of the shafts 23a and 23b of the electric motors 22A and 22B. Gears 30a and 30b of smaller diameter are engaged with the gears 29a and 29b. The axes of the gears 30a and
30b are supported on a bearing housing 28. Electric power source cords 31 to an alternating power source are connected to the vibratory electric motors 22A and 22B. The electric motors 22A and 22B are driven in the opposite directions.
Substantially semi-circular unbalance weights 24a and 24b fixed to one end portions of the rotary shafts 23a and 23b are rotated at the same speed in synchronization with each other, and in the opposite directions through the engagements of the
gears 30a, 30b and 29a, 29b. Thus a linear vibratory force is generated in a X direction as shown in FIG. 3.
Although, the vibratory drum machine 10' of the other type is constructed simply as above described and it has the following defects.
The drum body 11 of this type is in the shape of cylinder, too. And the cast components to be cooled and cleaned are moved along the central axis C of the drum body 11. It is supported resiliently by the coil springs 17a and 17b. Further, the
vibratory exciter mechanism 13' consisting of the two vibratory electric motors 22A and 22B is fixed onto the peripheral wall of the drum body 11. Further also in this type, the substantially semi-circular unbalance weights 24a and 24b are fixed to the
driving shafts 23a and 23b of the vibratory electric motors 22A and 22B. The gears of the same diameter and the same number of teeth are fixed to the one end portion of the driving shafts 23a and 23b and they are engaged with each other. Accordingly,
the two vibratory electric motors 22A and 22B are rotated at the same speed in the opposite directions and in synchronization with each other. Thus, a linear vibratory force is generated in a direction P as shown by a arrow in FIG. 5. It intersects
with the axis C of the drum body 11 at a right angle. When no cast components are supplied into the drum body 11, or when no load is applied to the drum body 11, different points on the peripheral wall of the drum body 11 are linearly moved as shown by
the arrows in FIG. 5. The direction of the movement of the points on the peripheral wall are substantially parallel with the linear vibratory force direction P.
It makes an angle .alpha. relative to the horizontal line H--H at the peripheral position at which the vibratory force generating mechanism 13' is mounted on the peripheral wall of the drum body 11. Thus, the points on the peripheral wall of
the drum body 11 are vibrated almost at the same amplitude and same vibratory angle.
When some cast components M to be cleaned and cooled are supplied into the drum body 11, the cast components M and sand S circulate as shown by the arrow in the same manner as above described prior art. However, the amplitudes of the points on
the peripheral wall are greatly decreased in comparison with those in the no-load condition. Accordingly, actually the circulating motion as shown is difficult to be obtained, and further the circulating speed is decreased since the amplitude is
smaller. Further, the fluidity is deteriorated in comparison with the above described prior art.
The reason for the above defect will be described. The cast components M to be cleaned and cooled are driven together with the drum body 11 in the vibratory direction P which is obtained under the no-load condition. The vibratory direction of
the point on the bottom of the drum body 11 is substantially equal to the direction P as shown by the arrow a.sub.1 '. However at the angle portion a.sub.2 ' of 45 degrees in the counterclockwise direction, the vibratory directions of the points are
substantially parallel to the direction P under the no-load condition. Accordingly, the direction of the vibration of the point at the angle 45.degree. is substantially parallel to the internal wall surface of the drum body 11 as shown by the arrow
a.sub.2 '. Accordingly, it is clear from the theory of the vibration that the acceleration of the point in the vertical direction to the surface of the inside wall of the drum body 11 is smaller than 1 G. Accordingly, the cast components and sands can
not jump from the wall surface of the drum body 11. The forward movement due to the vibration can not be imparted to the cast component and sands. Further, at a point of a larger angle, it is preferable to move the cast components and sands relative to
the inside surface of the drum body 11 in the counterclockwise direction. However, actually the cast components and sands are moved in the clockwise direction. Accordingly, the movement of the cast components and sands at the larger angle position
a.sub.3 ' is opposed to the movement of the cast components and sands at the lowest point a.sub.1 '. Thus, the cast components M and sands S separated from the cast components M push the inside wall surface of the drum body 11. As if the cast component
M and sands S is integrated with the drum body 11 as a rigid body, they are vibrated as one body. Accordingly, it is natural that the amplitude of the different points on the peripheral wall of the drum body 11 are decreased and the fluidity is
deteriorated as above described.
Further, in this prior art, the vibratory drum machine is driven, for example, at the power frequency of 60 Hz and vibrated at the rotational speed of 894 r.p.m. In the technical field of the vibration, the frequency of 894 r.p.m. belongs to
the super low frequency zone. Accordingly, the houses which are adjacent to or near the vibratory drum machine are almost under a resonant condition of the super low frequency vibration. Thus, the houses and further the doors and desks are vibrated. A
public nuisance is imparted to the people which live near the factory in which the above described vibratory drum machine is arranged.
Further, the gears are fixed to the driving shaft in the above described prior art. They are engaged with each other and they are rotated in the opposite directions. Even when the engagement with the gears is accurately designed, the engagement
sound can not be zero. Further, the noise is in a high frequency zone. Such a noise is of a public noise nuisance to the people which live near the factory in which the vibratory drum machine is arranged.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a vibratory drum machine in which amplitude decrease of different points can be small in contrast with the prior art, when some load is applied, and so fluidity of cast components and
sands can be improved.
Another object of this invention to provide a vibratory drum machine which can prevent public nuisance of the super low frequency to the houses near the factory.
In accordance with an aspect of this invention a vibratory drum machine for treating articles comprising: (A) a cylindrical drum body supported resiliently by springs; and (B) a circular or elliptic vibratory force generating source fixed on the
peripheral wall of said cylindrical drum body above the horizontal line passing perpendicularly through the central axis of said cylindrical drum body.
The foregoing and other objects, features, and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the preferred embodiments of the invention, taken in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a vibratory drum machine of a prior art;
FIG. 2 cross-sectional is a view taken along the line II--II of FIG. 1;
FIG. 3 cross-sectional is a view of a vibratory drum machine of another prior art, similar to FIG. 2;
FIG. 4 is an enlarged front view of a vibratory exciter in FIG. 3;
FIG. 5 is a cross-sectional schematic view of the other prior art for explaining the operations;
FIG. 6 is a side view of a vibratory drum machine according to a first embodiment of this invention;
FIG. 7 is a plan view of the vibratory drum machine of FIG. 6;
FIG. 8 is front view of the vibratory drum machine of FIG. 6;
FIG. 9 is an enlarged cross-sectional view taken along the line IX--IX in FIG. 7;
FIG. 10 is a cross-sectional schematic view of the vibratory drum machine of the first embodiment;
FIG. 11 is a cross-sectional view of a vibratory drum machine according to a second embodiment of this invention, similar to FIG. 2;
FIG. 12 is a graph for comparing the noise levels between the prior art and the first embodiment of this invention;
FIG. 13 is a front view of a vibratory drum machine according to a third embodiment of this invention;
FIG. 14 is a cross-sectional schematic view of the vibratory drum machine of FIG. 13 for explaining the operations;
FIG. 15 is a plan view of a vibratory drum machine according to fourth embodiment of this invention;
FIG. 16 is a side view of a vibratory drum machine according to a fifth embodiment of this invention;
FIG. 17 is a schematic view of a vibratory drum machine for explaining effects of the fifth embodiment;
FIG. 18 is a partly-broken schematic view of the vibratory drum machine of FIG. 17;
FIG. 19 is a schematic perspective view of a vibratory drum machine according to a sixth embodiment of this invention.
FIG. 20 is a graph for explaining effects of the sixth embodiment with respect to the beating phenomenon;
FIG. 21 is a side view of two vibratory drum machines arranged adjacent to each other for explaining the effects of the sixth embodiment;
FIG. 22 is a graph for explaining beating phenomenon of the vibratory drum machine of FIG. 21;
FIG. 23 is a side view of a vibratory drum machine according to a seventh embodiment of this invention;
FIG. 24 is a cross-sectional view taken along the line XXIV--XXIV in FIG. 23;
FIG. 25 is a partly-broken enlarged plan view of a vibratory exciter in FIG. 23;
FIG. 26 is a partly-broken front view of the vibratory exciter of FIG. 25;
FIG. 27 is a cross-sectional view taken along the line XXVII--XXVII in FIG. 26;
FIG. 28 A to D is a front view of unbalance weights in FIG. 27:
FIG. 29 is a schematic view for explaining operations of the seventh embodiment of this invention;
FIG. 30 is a cross-sectional schematic view of the seventh embodiment of this invention for explaining the effects;
FIG. 31 is a side view of a vibratory drum machine according to an eighth embodiment of this invention; and
FIG. 32 is a cross-sectional view taken along the line XXXII--XXXII in FIG. 31.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 6 to FIG. 10 show a vibratory drum machine according to a first embodiment of this invention. In FIG. 1, a vibratory drum machine is designated generally by a reference numeral 41A. A vibratory exciter 43 according to this invention is
arranged at one side of the peripheral wall of a cylindrical drum body 42. The drum body 42 is resiliently supported by supporting members 44a, 44b, 45a and 45b through coil springs 46a, 46b, 47a and 47b so that it is inclined downwards at an angle of a
few degrees. An inlet 48, through which cast components to be cooled and cleaned are supplied, is formed at the left end portion (FIG. 6) of the drum body 42 and an outlet 49, through which the cleaned and cooled cast components are discharged, is
formed at the right end portion of the drum body 42.
Reinforcement ribs 50 are fixed to the peripheral wall of the drum body 42 to strengthen the drum body 42. A right end open of the drum body 42 is covered partially with a cover member 51.
Next, there will be described the detail of the vibratory exciter 43 particularly with reference to FIG. 7 to FIG. 9.
The vibratory exciter 43 generates a circular vibratory force. An electric motor 64 is mounted on a supporting frame 63 arranged at the one side of the drum body 42. It is a drive source. A first link 65 is combined through a universal joint
mechanism to a end portion of the rotary shaft of the electric motor 64. Thus, the drive shaft of the electric motor 64 is combined through a universal joint 66b to a first link 65. A left end portion of the first link 65 is combined through a
universal joint 66a to a first support axis 69. The first support axis 69 is fitted to inner races of a pair of bearings 68a and 68b fixed at both sides of the mounting plate which is fixed to the drum body 42. A substantially semi-circular unbalance
weight 70a is fixed to one end portion of the first support axis 69. Another unbalance weight 70b having the same shape as the unbalance weight 70a is fixed to another end portion of the first support axis 69.
The first support axis 69 is combined through universal joints 72a, 72b and a secondary link 71 with a second support axis 75. A pair of bearings 74a and 74b is fixed to a support plate 73 which is, in turn, fixed to the peripheral wall of the
drum body 42. The second support axis 75 is rotatably fitted into inner races of the bearings 74a and 74b. Unbalance weights 76a and 76b having the same shape as the above described unbalance weights 70a and 70b are fixed to end portions of the second
support axis 75.
According to this invention, a line L--L which connects a center P of the circular vibrating force, therefore a central axis of the drive shaft (link) 65 with a central axis C of the drum body 42 is so designed as to make an angle .beta. of 25
degrees relative to a horizontal line H--H. The heights of the mounting frame 63 and the shape of the mounting plate 67 are so designed as to obtain the above described angle of 25 degrees. Further, according to this embodiment, the rotational direction
of the electric motor 64 for driving the drive shaft (link) 65 is in the clockwise direction.
A pair of observing windows 61a, 61b is formed on the upper wall portion of the drum body 42. As shown in FIG. 8, an arcuate stop plate 62 is fixed at the bottom portion of the inside wall of the drum body 42 near the outlet 49.
Next, there will be described operations of the above described vibratory drum machine 41A according to the first embodiment of this invention.
Although not shown, cast components to be cooled and cleaned, are supplied into the inlet 48 of the drum body 41. The electric motor 64 is driven. The rotary force of the drive shaft of the electric motor 64 through the universal joints 46a,
46b and the first link 65 drives the pair of the unbalance weights 70a and 70b. Further, the first support axis 69 fixing the unbalance weights 70a and 70b drives the unbalance weights 76a and 76b fixed to the end of the second support axis 75 through
the universal joints 72a, 72b and second link 71. A centrifugal force or a circular vibratory force is generated around the central axis of the support axes 69, 75 with the rotation of the unbalance weights 70a, 70b, 74a and 74b. It is transmitted to
the drum body 42 to vibrate the latter in the following manner. The rotational shaft of the electric motor 64 is combined through the universal joint 66a and 66b with the unbalance weights 70a and 70b. Further, the first support axis 69 is combined
through the universal joint 72a and 72b with the unbalance weights 76a and 76b. Accordingly, the vibration is scarcely transmitted to of the drum body 42 the electric motor 64. Thus, the electric motor 64 continues stably to rotate.
FIG. 10 shows relationships among the central axis C of the drum body 42, a gravity center G of the whole drum body 42 and the central point P of the circular vibratory force of the exciter 43. The circular vibrating force F as shown in FIG. 10
is generated with the drive of the exciter 43. A rotational moment is generated around the gravity center G. The drum body 42 is represented by a circular line in FIG. 10. The distance between the central point P of the circular force F and the
peripheral wall of the drum body 42 is shown in FIG. 10. Points on the peripheral wall of the drum body 42 vibrate in the shown manners. Some points on the peripheral wall portion of the drum body 42 nearest to the exciter 43 vibrate elliptically in
the manners as shown by a.sub.1, a.sub.2, a.sub.3, and a.sub.4. Long axes of the elliptical vibrations a.sub.1, a.sub.2, a.sub.3 and a.sub.4 and short axes thereof on the points near the exciter are larger than thoes of elliptic vibrations on other
points on the peripheral wall portion of the drum body 42. Further, the inclinations of the long axes of the elliptic vibrations of the points on the peripheral wall portion of the drum body 42 are changed along the peripheral wall in the manners as
shown in FIG. 10. Points on the bottom wall portion of the drum body 42 vibrate linearly or elliptically as shown by b.sub.1, b.sub.2, b.sub.3 and b.sub.4. The directions of the long axes of the elliptic vibrations b.sub.1, b.sub.2, b.sub.3 and b.sub.4
are so inclined as to impart a forward movement to the cast components M and sands S in the counterclockwise direction relative to the inside wall surface of the drum body 42. Points near the top end wall portion of the drum body 42 vibrate in in
elliptical forms as shown d.sub.1, d.sub.2, d.sub.3 --. The long axes of the elliptic vibration d.sub.1, d.sub.2 and d.sub.3 and short axes thereof become smaller in the order of the d.sub.1, d.sub.2, d.sub.3 --. Further, the locus of the elliptical
vibrations b.sub.2, b.sub.3, b.sub.4, c.sub.1, c.sub.2 --rotate in the clockwise directions in FIG. 10. The vibrations d.sub.1, d.sub.2, and d.sub.2 are elliptical and the locus of thereof rotate in the clockwise direction. However, the directions of
the long axes of the elliptic vibrations a.sub.1, a.sub.2 and a.sub.3 are substantially parallel to the tangent line on the points of the inside peripheral surface of the drum body 42. Accordingly, the movement force by vibration is almost zero above
the points. In FIG. 10, a linear vibration as shown by e is made at an angle of about 170 degrees with respect to the vibration a.sub.1 and the central axis C of the drum body 42 in the counterclockwise direction. Elliptic vibrations f.sub.1, f.sub.2,
f.sub.3 and f.sub.4 are obtained between the bottom portion of the inside wall portion and the angle position of about 170 degrees. The long axes of the elliptic vibrations f.sub.1, f.sub.2, f.sub.3 and f.sub.4 and the short axes thereof become larger
in that order. The rotation of the locus of the elliptic vibrations f.sub.1, f.sub.2, f.sub.3 and f.sub.4 are in the counterclockwise direction. A linear vibration b.sub.1 is made at the most lower portion of the inside wall of the drum body 42. In
the counterclockwise direction from the bottom point of the inner wall of vibratory drum body 42, the above described elliptic vibration are made. The rotations of the locus of the elliptic vibrations are in the clockwise directions.
The above vibration modes have been obtained by an electronic computer. The original point of X-Y rectangular coordinates-abscissa is made to be equal to the central axis C of the drum body 42. The dimensions of respective parts of the
vibratory drum machine are followings:
______________________________________ Diameter of the drum body D (CM) 120.0 Weight of the whole vibratory drum W (Kg) 1970.0 machine Inertial moment around the gravity AI (KgSqCM) 8820000.0 center of the vibratory drum machine X
coordinate of the gravity center of XM (CM) 18.3 the whole vibratory drum machine Y coordinate of the gravity center of YM (CM) 7.6 the whole vibratory drum machine X coordinate of the position of the SS (CM) 38.3 exciter The number of the
vibration M (RPM) 900.0 The amplitude at the most lower por- AT (mm) 9.0 tion of the vibratory drum Exciting force F (Kg) 5664.7 ______________________________________
The cast components M and sands S supplied through the inlet 48 of the drum body 42 are subject to the above described vibrations in the inside of the drum body 42. The drum body 42 is downwards inclined at the angle of about 2 to 3 degrees.
Accordingly, they are moved rightwards in FIG. 6. As shown in FIG. 10, the cast component M and sands S are moved upwards along the inside wall surface of the drum body 42 in the counterclockwise direction. When they are moved up to a predetermined
level of the drum body 42, the gravitational force becomes larger than the movement force by the vibrating force. Accordingly, the cast components M and sands S slide down along the upper layer of the cast components M ans sands S. As the result, the
cast components M and sands S move as shown by the arrow Q. In the circulating motion, the cast components M and sands S are sufficiently stirred and moved rightwards along the central axis C (FIG. 6). The sands S are sufficiently separated from the
cast components M and the cooling operation is sufficiently effected. The cooled and cleaned cast components M and sands S are discharged outwards through the discharging outlet 9. As shown in FIG. 8, the arcuate stop plate 62 is arranged along the
inside wall surface of the vibratory drum 42. Accordingly, the cast components M and sands S can be sufficiently stirred in a long time within the vibratory drum 42 and then they are discharged through the discharge outlet 49. If there is no stopping
plate 62 and occupation rate of the cast components M and sands S in the internal space of the drum body 42 is small, the cast components M and sands S could not receive sufficient stirring operation and are discharged through the outlet 49.
Accordingly, the effect of the stop plate 62 is remarkable in the case when the occupation rate of the cast components and sand in the drum body 42 is small. In the above described manner, the cast components M to be cleaned and cooled are stirred and
moved. The vibrations b.sub.1, b.sub.2, b.sub.3, b.sub.4, c.sub.1, c.sub.2 --of the points of the peripheral wall of the drum body 42 can be obtained under the no-load condition in which no cast components M and sands S are supplied. Even when the cast
components M to be cooled and cleaned are supplied at the occupation rate as shown in FIG. 10, the amplitude decrease is very small in comparison with the prior art vibratory drum m | | |
