JPH0581343B2 - - Google Patents

Description

Claim 1: A formwork for holding particulate matter, a master form associated with the formwork, a hopper positioned on the master form for distributing a flow of particulate matter to the master form, and a hopper positioned within the hopper. , a cooling means for cooling the granular material fed through the hopper, and a first plate each having a plurality of holes and juxtaposed with the first plate. In the second plate, each of the plurality of holes may be mutually aligned to define a passage for particulate matter, the passageway for particulate matter to fall selectively and non-uniformly towards the formwork. the first plate and the second plate are relatively irregularly spaced apart so that each of the plurality of holes can accommodate the desired amount of granules into the formwork; means for relatively adjustable mounting so as to be brought into relatively adjustable alignment so as to select the flow rate of the particles; and means for advancing particulate matter towards said first plate. vibrating means for vibrating the cooling means; and vibrating means for vibrating the formwork to avoid the formation of gaps in the formwork, thereby uniformly compacting around the master form. Foundry equipment.

2. A formwork for holding particulate matter, a master form associated with the formwork, a hopper positioned on the master form and for distributing the flow of particulate matter to the master form, and a particulate matter conveyed from the hopper. and a cooling means inside the hopper for cooling the hopper, the casting apparatus comprising a first plate each having a plurality of holes, and a second plate juxtaposed to the first plate. , each of the plurality of holes may be aligned with one another to define a passageway for particulate matter, the passageway being non-uniform in size to cause particulate matter to fall in greater amounts on some portions of the master than on other parts. the first plate and the second plate; and the plurality of holes in each of the first plate and the second plate are relatively adjusted to select a desired flow rate of particulates into the formwork. means for adjustably attaching the first plate and the second plate relative to each other so that the first plate and the second plate can be brought into alignment; The casting apparatus comprises: a vibration means for vibrating the cooling means; and a vibration means for vibrating the mold to avoid the formation of gaps in the mold, thereby uniformly compacting the periphery of the mold. .

3 A mold for holding molding sand, a master mold associated with the mold, a hopper positioned on the master mold for distributing sand flow to the master mold, and a hopper for distributing sand flow to the master mold, and a granular material conveyed from the hopper. a first plate having a first plurality of regularly spaced holes; said first plate having a uniform perforation area; means for mounting said first plate with respect to a foundry so as to block sand flow from said hopper; a second plate comprising a second plurality of holes matching the first plurality of holes in position and number; at least one of the second plurality of holes has an area larger than the other holes; the second plate is small so that when the first plate and the second plate are aligned, the amount of sand that falls through each hole is non-uniform; selectively aligning each of the plurality of holes in the plate so that the first
means for adjustably mounting one of the first plate and the second plate relative to the other to establish a desired sand flow rate through each of the plurality of holes in the plate and the second plate; and vibrating means for vibrating the cooling means to advance the particulates towards the first plate; vibrating the formwork to avoid the formation of gaps in the formwork, thereby vibrating the periphery of the master form. vibrating means for uniform compaction.

4. A formwork for holding molding sand, a master form associated with the formwork, a hopper positioned on the master form to distribute sand flow to the formwork, and granules conveyed from the hopper. cooling means within said hopper for cooling said hopper, said first plate having a first plurality of regularly spaced holes; said first plate having holes of uniform area; means for mounting said first plate with respect to a casting apparatus such that said first plate blocks sand flow from said hopper; a second plate juxtaposed to the first plate, with a plurality of holes in the first plate so that at least a portion of the formwork is covered by the sand flow falling from the first plate and the second plate; selectively aligning each of the plurality of holes of the first plate and the second plate with the second plate having a plurality of holes with matching positions but a smaller number; Said first
means for adjustably attaching one of the first plate and the second plate relative to the other so as to establish a desired sand flow rate through the plurality of holes in each of the plates and the second plate; vibrating means for vibrating the cooling means to advance the object towards the first plate; vibrating the mold to avoid the formation of gaps in the mold, thereby uniformly surrounding the mold; and vibrating means for compaction.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to apparatus for forming casting molds, and more particularly to structures for controlling the distribution of sand within a mold for defining such molds.

BACKGROUND OF THE INVENTION Known metal forming processes use sand molds into which molten metal is poured and cast. Typically, a master model representing the desired part shape is positioned within the mold. Sand is compacted or compacted along the area of the pattern to reproduce its contours, and then the pattern is removed. The molten metal introduced into the mold takes the form of a cavity.

The prototype was made from expanded cellular polystyrene (hereafter simply
STAROFORM). This is economically more practical than the use of common wooden molds. The STYROFOAM prototype is
Upon introduction of the molten metal into the mold, it has the added advantage of being evacuated as a gas through the runner and gate system, leaving no residue that would impair the quality of the casting.

A measure taken in the prior art to ensure that the sand perfectly reproduces the contours of the original and does not create bridging or ledges that impede the passage of sand into tight, narrow depressions. is the tamping or compaction of sand against the original form. One such device that operates in this manner is US Pat.
No. 3234601. In the Hatch et al. patent,
An air-operated squeezing ram is used to compact the mold.

The main drawback with this type of mold formation is that it cannot be used when delicate molds are used, such as those with elongated protrusions or fingers, or when STYROFOAM constitutes the mold. The original mold may be bent and/or destroyed by the impact of the pressing cylinder. The use of a ceramic coating on STYROFOAM to increase its stability reduces, but does not eliminate, the problem of pattern deformation. Even slight variations in the master pattern can result in a defective and/or unacceptable casting.

An alternative to compaction-type molding is a vibratory system that operates to vibrate the mold and form to evenly distribute and compact the sand around the form. Although this particular process is generally satisfactory, it still involves the problem of mold breakage as the sand collides with the mold.

In a typical apparatus, a hopper is disposed above the formwork and associated pattern. Generally, in most equipment the sand falls freely onto the pattern. If there is nothing to obstruct the flow of the hopper, the sand flowing down may damage part of the mold pattern. Although reducing the flow rate to the formwork prevents damage to certain delicate parts of the mold, it slows down the overall operation and creates a bottleneck in the assembly line. It is clear that this is an important economic issue.

The present invention is particularly directed to overcoming the above-mentioned drawbacks in a new and simple manner.

SUMMARY OF THE INVENTION In accordance with the present invention, a sand distribution structure is provided below the supply hopper to control the distribution of sand around the pattern within the formwork. The primary objective of the present invention is to deliver sand to the mold at a rate commensurate with the mold's ability to withstand the impact of the sand. Therefore, the mold can be formed at the fastest speed without risking damage to the mold pattern.

To accomplish this objective, first and second perforated plates are provided and are mutually adjustably mounted so that the perforations can be selectively aligned to define a sand flow path therethrough. The size and location of the holes in the plate are selected for the desired flow rate;
It can be varied to completely block parts of the pattern from the direct flow of sand and select different sand flow velocities for different parts of the pattern.

In another aspect of the invention, a vibrating device is provided and operated independently to separately vibrate the hopper and formwork. The vibration of the hopper ensures a constant and continuous flow of sand from the hopper to the plate.
The vibrations of the formwork work together with sand control plates to compact the sand evenly around the perimeter of the form.

Other objects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the drawings and appended claims.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a vibratory sand and foundry handling system incorporating therein a preferred form of a distribution controller according to the present invention.

FIG. 2 is a partial cross-sectional view of the sand distribution controller taken along line 2--2 of FIG.

FIG. 3 is a partial cross-sectional view of the adjustable plate associated with the sand distribution controller, taken along line 3--3 of FIG.

FIG. 4 is a partial plan view of one sand distribution plate fixed in relation to the apparatus and shown in relation to the dotted pattern below it;

FIG. 5 is a plan view of an adjustable plate for use in conjunction with the plate of FIG. 4 to adjustably define sand passages through the sand distribution device.

FIG. 6 is a plan view of the plates of FIGS. 4 and 5 with the plates in operative relationship with each other and with respect to the underlying master; FIG.

7 is a plan view of a modified structure for the adjustable plate of FIG. 5; FIG.

8 is a plan view of the plates of FIGS. 4 and 7 in operative relationship with each other and with the underlying master; FIG.

9 is a plan view of yet another variation of the adjustable plate structure of FIG. 5; FIG.

FIG. 10 is a plan view of the plates of FIGS. 4 and 9 in operative relationship with each other and with respect to the underlying master; FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a sand and casting handling system is shown at 10 in FIG. This system is representative of an environment to which the present invention is particularly suited. Generally, the system 10 of FIG. 1 includes a sand classification station at location 12, a transfer conveyor 14, a feed hopper 16,
It consists of a formwork support station at location 18 and a sand distribution section at location 20, which forms the essential part of the invention.

At the sand classification station 12, sand of the desired particle size is directed to a transport conveyor 14. The transport conveyor 14 consists of a longitudinally oriented endless conveyor 22 rotating around spaced apart pulleys 24 . A conveyor 22 operates within an enclosed shroud 26 and advances sand toward a shroud cap 30 from an inlet 28 adjacent the sand classifier near the bottom of the shroud. Particles fall from the conveyor top 32 and enter a bin 34 associated with a hopper. Cap 30 intercepts airborne particles and diverts them to pin 34.

The bin 34 is independently supported by four upright posts 36 that support the underside of an upper rim 38 at an upper edge 40 that frames the upper entrance 42 of the bin. The pin has a main body 44 with a constant cross-sectional area. An integral sloping chamber 46 allows the material to be
from there into the formwork 48 which is supported on the lifting device at position 50 in a funnel-like manner.

The details of the operation of the system according to the invention are clearly shown in FIG. In effect, system 10 constitutes one station along a casting assembly line. The formwork 48 is rotatably supported by a support frame 53 and has rails (not shown) guided along serially arranged rollers 52 that cooperate to define a predetermined guide path. By equipping it, it can be transported between stations. The formwork is supported on the underside 56 of the formwork and is moved up and down by a lifting mechanism 50.
It is raised to the operating position shown in FIG. 2 by a platform 54 associated with it, and lowered therefrom. The lifting mechanism 50 is selectively raised and lowered by four pneumatic lifts of conventional construction. Formwork 48
When moving the frame away from the position shown in Figure 2, the pneumatic lift
0 and causes the formwork and associated rails to rest on rollers 52. The formwork is moved away by a suitable mechanism and replaced by a new formwork 4.
8 is replaced. With the new formwork 48 disposed in alignment with the lower hopper, the upwardly facing wall 64 of the formwork 50 is flush with the back side 56 of the formwork.

The frame 60 is raised by a pneumatic lift 62 and away from the rollers 52 and the sand distribution section 20
is engaged with the bottom of the

The formwork 48 is preferably a cup-shaped chamber 6 having fixed walls 68 supporting a representative form 70 shown in FIG. 2 manufactured by STYROFOAM et al.
Consists of 6. The chamber has an outwardly bent peripheral rim 72 that abuts the bottom of the sand distribution section 20.
has.

Immediately above the sand distribution section are sand cooling chambers 76, 78. Each chamber 76, 78 is provided with a cooling coil 80 for circulating air through the sand bed therein. This is necessary because sand is often reused over several casting operations and may therefore be introduced into the hopper at an elevated temperature from its previous use. Cooling ensures that the temperature of the sand is low enough to avoid thermal damage to the chamber or sand distribution section.

In conventional work, the sand from the hopper is the original 7
It rained continuously over the area around 0. Although the original shape in FIG. 2 is generally strong enough to withstand most impacts, the opposing extending fingers 81 are very fragile. The fingers 81 are extremely susceptible to damage due to the load of flowing sand.

This problem is overcome by providing a sand distribution structure 20 as detailed in FIGS. 2-10. The sand distribution structure 20 is comprised of a first fixed plate and a second plate 84 adjustably mounted with respect to the fixed first plate 82 .
The first and second plates are both planar and have adjacent surfaces 86, 88 which bring the plates into abutting sliding, juxtaposed relationship. Inside each plate there are holes that allow sand to pass through. By adjusting the second plate with respect to the first plate, a desired amount of alignment between the holes can be selected. The specific shape and arrangement of holes is shown in FIGS. 4-10 and described below.

Returning to the basic structure of FIGS. 3 and 4, the first plate 82 is adjacent to both ends 90, 92,
It is shown attached to the underside 94 of an L-shaped member 96 that is rigidly secured to a support frame 98 associated with the sand distribution controller.

The second plate 84 is connected to the control rod 10.
4 have depending flanges 100, 102 drilled through a common line to receive the 4.

Plate 84 has an L-shaped bracket 108 attached to support frame 98 at its edge extending parallel to the adjustment actuation line indicated by double-headed arrow 106.
longitudinally supported by. The second plate has nuts 1 screwed onto both sides of the flange 100.
10 in the desired position relative to the rod 104. With the plates in the desired position, the nuts 110 are drawn close together to constraintly clamp the flange 100 and fix the position of the rod 104. Another nut 11
2 is threaded onto the rod so as to abut the surface 114 of the flange 102 associated with the second plate. To adjust the second plate with respect to the first plate,
The nuts 110, 112 are loosened and the plate is actuated longitudinally along the rod in both directions indicated by arrow 106 until the desired flow conditions are achieved. The nuts are then pulled together once the relative plate positions are established.

A shutoff actuator 116 is associated with the plate 84 to move the plate back and forth between the set position described in the previous paragraph and the full shutoff position. Normally, the formwork is station 10 for sand flow.
and is stopped when leaving it.
Associated with support frame 98 is a fixed integral rim 118 that is substantially identical to formwork chamber rim 72 . The rims 72, 118 are attached to the formwork chamber 6 when the formwork chamber is in the operating position below the hopper.
6 and seal. A large flexible gasket 120 is installed between the rims 72, 118 to keep foreign objects out of the formwork and to establish an effective seal that accommodates multi-dimensional relative motion between the formwork and the hopper section.
is inserted and compressed and held in between.

Details of the holes in plates 82, 84 will be described in conjunction with FIGS. 4-10. FIG. 4 shows a first plate 8 associated with one of the lower prototype fingers 81.
2 is shown. Each hole 122 is square and circumferentially defined by an edge 124 having a length X. Hole 1
22 are arranged in rows, each row being offset from the adjacent row by an equal distance both in the longitudinal direction of the row and in the perpendicular direction thereof.

One arrangement for holes 222 in second plate 84 is shown in FIG. Each hole 222 is square, with the center 126 of the hole 12 of the first plate 82
This corresponds to the position of the center 128 of 2. The dimensions of edge 130 defining hole 222 are shown as FIG. 5Y. The length of Y is the dimension of the hole 122 in the plate 82
slightly larger than

FIG. 6 shows plates 82, 84 in side-by-side relationship, with holes 122, 222 partially in alignment. It will be seen that edges 124 and 130 are substantially parallel so that perfect alignment of hole 122 with larger hole 222 in the second plate is achieved. The flow path 132 defined by the aligned holes is adjustable between a fully blocked position and a fully aligned position where the area of the sand passage is equal to the area of the smaller hole, hole 122. The flow rate is selectable as required and is substantially uniform throughout the lower region of the plate.

FIG. 7 shows an alternative structure of the second plate 84 of FIG. The holes 322 are substantially the same shape and oriented in the same manner as those in FIG.
However, the three holes immediately above the finger 81 are omitted to hide the upper area of the finger. Referring to FIG. 8, which shows the operative juxtaposition of plates 82, 184, it is observed that the flow is substantially uniform and identical throughout to that of FIG. 6, except for the blocking area at location 134. It will be. By blocking the sand flow, the finger 81 is protected from falling sand. Sand is applied around the fingers and gradually accumulates from the area around the fingers towards the fingers. In the plate 184 of FIG.
22 is omitted, but any number may be omitted based on the particular shape of the prototype.

In FIG. 9, hole 422 matches the shape and orientation of holes 222, 322 in FIGS. 5 and 7, respectively. However, rather than omitting the holes near the finger 81, a smaller hole 136 is substituted. Hole 136 has an edge dimension Z that is smaller than both X and Y in the previous structure. The relative positions of modification plate 284 of FIG. 9 and plate 82 of FIG. 4 are shown in their operative juxtaposition.
It will be appreciated that the smallest holes 136 are the critical passage area and will cause flow up the finger at a much lower rate than will occur over the remainder of the formwork. In the process, the fingers are protected from the impactful direct flow of sand during the period when sand buildup around the fingers occurs. Rapid introduction of sand other than above the fingers is possible.

Another aspect of the invention is the provision of independent vibration means 138, 140 on the support frame 98 associated with the hopper and formwork, respectively. Both vibration means are of conventional construction and consist of a motor 142 having a drive shaft 144 carrying eccentric weights 146 at both ends. Frame 9
8 is a sample beam 1 horizontally suspended between the upright supports 36.
By providing a monolithic ear 148 mounted on a breakaway spring 150 with its lower end resting on 52,
Mounted for oscillating motion. The vibratory motion imparted by motor 142 is minimal compared to the vibrations via motor 143. motor 142
is a plate 82 associated with the sand distribution section;
84 to establish a vibration that prevents the hanging shelf phenomenon of the material.

The main role of the vibration applied via the motor 143 is to compact and distribute the sand well along the pattern. The vibration is sufficient to prevent bridging and shelving across deep grooves and complex geometries. Sand distribution section and vibration device 1
40, 142 work together to ensure that the sand is distributed in a controlled manner to the mold and that the sand ultimately surrounds the mold completely and compactly to form a serviceable mold.

Effects of the Invention By omitting an arbitrary number of holes or making the size and shape of the holes smaller than others, it is possible to block or reduce the amount of sand flowing into such areas and protect them from destruction. This makes it possible to rapidly introduce sand into surrounding areas other than the above-mentioned areas of the original form through holes of larger size and shape, which previously could not be achieved by simply reducing the amount of sand flowing down. However, this has the effect of preventing both work delays and the economic problems associated with them.

It is to be understood that the foregoing detailed description has been made for the purpose of illustrating the structure and operation thereof in accordance with the present invention, and no unnecessary limitations are to be derived therefrom.