Spiral-flow barrel finishing machine

Abstract: This invention relates to a spiral-flow barrel finishing machine comprising a cylindrical stationary metallic barrel (3) equipped with lining layer (2) at the lower inside and a rotating barrel (6) which equipped with lining layer (5) on a metallic rotational body (4) and loosely engaged with lower part inside of said cylindrical stationary barrel so as to rotate freely. And this invention discloses the spiral-flow barrel finishing machine with an object to keep a constant clearance (5) between inner wall of the stationary barrel (1) and outer wall of the rotating barrel (6), not relating with the temperature change and the moisture content change. The spiral-flow barrel finishing machine of the present invention is characterized in that a measure (7) to allow for thermal expansion having a specific vertical width, properly corresponding to the vertical width of the clearance, is circularly arranged between inner wall (1) of the metallic stationary barrel and outer wall of the lining layer (2) on the metallic stationary (3) barrel, to make allowance for thermal expansion of the lining layer (2) on the stationary barrel toward wall (1) side of the metallic stationary barrel.

Description: This invention relates to a barrel finishing machine. Particularly, this invention relates to a spiral-flow barrel finishing machine comprising a cylindrical stationary part (stationary barrel) and a rotary part (rotating barrel) which is loosely engaged inside one end of said cylindrical stationary barrel so as to rotate freely, with an object to keep a constant clearance between an inner wall of the stationary barrel and an outer wall of the rotating barrel, not relating with the temperature change and the moisture content change. The prior art discloses a variety of procedures for preventing a clearance between the stationary barrel and the rotating barrel of the spiral-flow barrel finishing machine from changing of its radial width, which is caused by thermal expansion. For example, Japanese patent under Provisional Publication No. 5-38670 and Japanese utility model under Provisional Publication No. 3-130358 disclosed a machine in accordance with the preamble of claims 1 to 3. In this machine, a stopper is installed inside a lining layer on the periphery of a rotating barrel to control deformation of the lining due to thermal expansion. Japanese utility model under Provisional Publication No. 57-53858 disclosed a device wherein a foreign material is used for delimiting a fine clearance at either a stationary barrel part opposed to the fine clearance or a rotating barrel part opposed to the fine clearance. And furthermore, Japanese utility model under Provisional Publication No. 51-62191 disclosed a device wherein a clearance between a stationary barrel and a rotating barrel is adjusted vertically. These prior art procedures produce some negative effects as follows: a) The procedure for installing a stopper within the lining layer on the periphery of the rotating barrel can not afford to prevent either the clearance from shrinking due to thermal expansion in the severe usage for long time or durable life of the lining from shortening due to exposure of the stopper caused by abrasion of the lining layer. If the stopper is exposed by abrasion of the lining layer, it is necessary to re-install the lining layer. A bimetal type stopper may be available, but an increase in the cost is problematic. b) The procedure for using a foreign material at either the stationary barrel part or the rotating barrel part may accelerate abrasion, resulting in a short durable life. c) The procedure for vertically adjusting a clearance requires an adjusting mechanism, so that it is problematic due to not only an increase in the cost but also poor sealability. The present invention provides spiral-flow barrel finishing machines according to the independent claims 1 to 3. While studying direction about thermal expansion of the lining layer, which is installed on the inner wall of the stationary barrel, the inventors found that, although the lining layer inside the metallic stationary barrel is to be expanded on heating toward the metallic stationary barrel, it is blocked to expand by the metallic wall of stationary barrel, so that this thermal expansion is forced to divert the direction toward center (inner) of the stationary barrel (resulting in reducing radial width of clearance between inner wall of the lining layer on the stationary barrel and outer wall of the lining layer on the rotating barrel). In accordance with this invention, as a measure to allow for thermal expansion of the lining layer installed in the stationary barrel, a flexible layer having a specific axial width, which can be deformed by thermal expansion of the lining layer installed inside the stationary barrel, is peripherally arranged between an inner wall of the metallic stationary barrel and an outer wall of the lining layer installed in the metallic stationary barrel, so that the heretofore mentioned problem can be resolved. A measure to allow for thermal expansion may be made up by installing an easily deformable elastic layer or air layer, used by alone or combined, between an inner wall of the metallic stationary barrel and outer wall of the lining layer installed in the metallic stationary barrel. A cylindrical metallic stationary barrel may be comprised by a cast-iron body and a polyurethane lining layer and a measure to allow for thermal expansion may be made up by installing a continuous-porous material layer between an inner wall of the said cast-iron stationary barrel and an outer wall of the said polyurethane lining layer. Moreover, a measure to allow for thermal expansion may be made up by molding irregularities on the outer wall of the lining layer facing to inner wall of the said cast-iron stationary body. By peripherally arranging a structure to allow for thermal expansion of the lining layer installed in the metallic stationary barrel between an inner wall of the metallic stationary barrel and an outer wall of the lining layer installed in the metallic stationary barrel, the said lining layer may be feasible to expand freely on heating toward the wall side of the metallic stationary barrel. Accordingly, the clearance between the stationary barrel and the rotating barrel of the spiral-flow barrel finishing machine can always be kept constant, not relating with the temperature change and the moisture content change. The axial height of the structure to allow for thermal expansion is required to correspond to the axial height of the radial clearance between the inner wall of the lining layer installed in the metallic stationary barrel and the outer wall of the lining layer installed on the rotating barrel, because at least by choosing the same size for both axial heights, preferably larger size for the former, the said clearance can be adjusted to keep constant at every position across its axial height. Namely, the vertical height of the structure to allow for thermal expansion is preferably about 3-fold larger than the axial height of the clearance to be adjusted. The reason is that adjustment of the clearance can be carried out more correctly and easily comparing with the case when the height is not as large as 3-fold size. Also, even if the height is chosen to be much larger than the 3-fold size, neither specific effects of adjustment of the clearance nor profits in manufacturing and cost are expected. Practically, the height of the structure to allow for thermal expansion is determined for preventing the size of the radial clearance between the stationary barrel and the rotating barrel from being affected by the thermal expansion of the lining layer installed in the metallic stationary barrel. Furthermore, it is preferable to locate the structure to allow for thermal expansion of the lining layer installed in the metallic stationary barrel at almost the same height as the clearance between the barrels is positioned. In this way, it is feasible to effectively adjust the clearance while keeping the clearance uniform across every vertical direction. Moreover, thicknesses of the elastic layer, air layer and continuous-porous material layer, or depth of irregularities in lining layer facing the inner wall of the metallic stationary barrel, are chosen to have equivalent absorptive power for thermal expansion of the lining layer installed in the metallic stationary barrel, orientating to the inner wall thereof. For example, assuming that 0.5∼1.5 mm of thermal expansion of the lining layer installed in the metallic stationary barrel takes place at 60∼70 degree C temperature of the stationary barrel or the rotating barrel, at least 6 mm thickness of the structure to allow for thermal expansion may be required. But, in case of an air layer, a 4 mm-thick layer may be enough to attain the purpose. Then, since the lining layer on the rotating barrel expands on heating outwardly (toward narrowing the clearance between inner wall of the lining layer installed in lower part inside the metallic stationary barrel and outer wall of the lining layer on the rotating barrel) and the lining layer on the stationary barrel also expands on heating outwardly (toward widening the said clearance), the clearance between the stationary barrel and the rotating barrel remains constant (that is to say, it remains design size) in the case when no different amounts of the thermal expansion exist between these lining layers. Accordingly, in order to keep a constant clearance between the stationary barrel and the rotating barrel, it is desirable that the external thermal expansion of the lining layer on the rotating barrel (toward narrowing the clearance) and the external thermal expansion of the lining layer on the stationary barrel (toward widening the clearance) are kept at relatively the same rate at each temperature range. If the lining layer on the stationary barrel is thick and the lining layer on the rotating barrel is thin, as the temperature increases, amount of thermal expansion of the former lining layer becomes so large that some adjustment may be carried out to let a part of the former lining layer capable to expand inwardly by increasing deformation resistance of the structure to allow for thermal expansion (e.g. by using continuous-porous material layer). Thereupon, by choosing the structure to allow for thermal expansion (e.g. continuous-porous material layer) with required thickness, such as with 4 mm thickness, instead of usual 6 mm thickness, a method to preferably adjust the thermal expansion may be achieved; i.e. outward expansion of the lining layer on the stationary barrel is proceeded smoothly at the initial stage, and then two-way expansions such as outward and inward expansions of the lining layer on the stationary barrel are caused along with the increase of the amount of thermal expansion as the temperature increases according to the deformation resistance of the measure to allow for thermal expansion having a specific thickness such as with 4 mm thickness. In this method, the purpose may be achieved by adjusting not only thickness but also axial height of the structure to allow for thermal expansion (e.g. continuous-porous material layer). If the clearance between stationary barrel and rotating barrel is always kept constant, as explained above, even if the clearance is determined as fine as allowable at the beginning of the design, any worrisome problem such as closing and meltdown of the clearance may be prevented. It gives another profitable outcome of being able to polish or finish materials in the barrel using fine workpieces, thin plate workpieces, fine abrasive chips without taking account of their blocking or fastening on the clearance between the stationary barrel and the rotating barrel. In the case when continuous-porous material is used as a structure to allow for thermal expansion of a polyurethane lining, the said continuous-porous material having a specific axial height and specific radial thickness is fixed on a definite part of the inner wall of the metallic stationary barrel at the first, and then the lining layer may be equipped inside the metallic stationary barrel by the same molding procedure, which has been adopted in manufacturing a conventional spiral-flow barrel finishing machine, without causing any further cost other than the cost required for manufacturing a conventional spiral-flow barrel finishing machine. The rotating barrel of a spiral-flow barrel finishing machine of this invention has the advantageous effect that installation of a stopper in the lining layer of rotating barrel for controlling thermal expansion of the said lining layer, as described in prior art, and thinning of a lining layer on the stationary barrel are not necessary. Hitherto, since a thick lining layer of the stationary barrel yields a large amount of inward expansion on heating, the upper thickness of lining layer on the stationary barrel has been limited. In a machine embodying the present invention, the thickness of the lining layer on the stationary barrel may be increased compared to that of a conventional spiral-flow barrel finishing machined; the spiral-flow barrel finishing machine of the present invention may be used for a long time, since it takes a long time till the lining layer on the stationary barrel is worn off. Therefore, the life span of spiral-flow barrel finishing machine may be increased, and it may provide a cost merit comparing to the structure of prior art in which the stopper is installed in the lining layer of rotating barrel. Brief Description of Drawings FIG. 1 shows a front view, partially in cross section, of a preferred embodiment of this invention. FIG.2 shows an enlarged sectional view of the preferred embodiment illustrated in FIG. 1, with certain parts omitted. FIG.3 shows an enlarged sectional view of the second preferred embodiment, with certain parts omitted. FIG.4 shows an enlarged sectional view of the third preferred embodiment, with certain parts omitted. FIG.5 shows an enlarged sectional view of the fourth preferred embodiment, with certain parts omitted. FIG.6 shows an enlarged sectional view of the fifth embodiment, with certain parts omitted. FIG.7 shows an enlarged sectional view of the sixth preferred embodiment, with certain parts omitted. EXAMPLE 1 As shown in Fig. 1 and Fig. 2, a cast-iron stationary barrel 1 whose inside and lower part is integrated with polyurethane lining layer 2 is referred to as stationary barrel 3. In this stationary barrel 3, a continuous-porous neoprene rubber plate 7 with a specific thickness (e.g. 6 mm) was circularly arranged between an inner wall at a lower part of the cast-iron stationary barrel 1 and an outer wall of the polyurethane lining layer 2 (Fig. 1). This continuous-porous neoprene rubber plate 7 constitutes a structure to allow for thermal expansion. Meanwhile, a cast-iron rotational barrel 4 equipped with polyurethane lining layer 5 at the upper part thereof to block a bottom part of the stationary barrel 3 is referred to as rotating barrel 6 (Fig. 2). The barrels 4, 6 have a common vertical axis about which the barrel 6 rotates. The axial height of the neoprene rubber plate 7 is, for example, 70 mm. The size of the axial height (vertical width) of neoprene rubber plate 7 is determined according to the size of the axial height (vertical width) of a radial clearance S between stationary barrel 3 and rotating barrel 6. Anyhow, the sizes of vertical width and radial thickness of neoprene rubber plate 7 are determined under the condition that the size of radial clearance S between stationary barrel 3 and rotating barrel 6 is stabilized or kept almost constant all the time, not relating with the thermal expansions of the polyurethane lining layer 2 and the polyurethane lining layer 5. The rotating barrel 6 is loosely engaged with the lower part of the inside of the stationary barrel 3 so as to rotate freely and oppose to each other forming a fine radial clearance S (e.g. 0.1∼1 mm) (Fig. 2). In this embodiment, the axial height (vertical width) of the clearance S between stationary barrel 3 and rotating barrel 6 is, for example, 20 mm. As shown in Fig. 1 and Fig. 2, the neoprene rubber plate 7 is located at almost same height as the clearance S is positioned. In Figure 2, an air vent 8 is used for venting the occluded air, which was occluded in the continuous-porous neoprene rubber plate 7, when the continuous-porous neoprene rubber plate 7 is deformed by thermal expansion of the polyurethane lining layer 2. Also, in Fig. 2, numerals 9 and 10 indicate the rotation axis and the supporting bottom of the rotating barrel 6 and the stationary barrel 3, respectively. In this embodiment, while the barrel 6 filled with workpieces and abrasive chips is rotating, temperatures of the stationary barrel 3 and the rotating barrel 6 increase (e.g. around 60 degree C) during the progress of the finishing process, wherein the polyurethane lining layer 5 of the rotating barrel 6 expands on heating to the arrow direction 11 (outward) resulting in narrowing clearance S; on the other hand, the lining layer 2 of the stationary barrel 3 expands on heating to the arrow direction 12 (toward inner wall of the cast-iron stationary barrel 1), resulting in broadening clearance S. In this case, if the effects of thermal expansion of these lining layers 2, 5 on the clearance S are compensated by each other, the clearance S always remains constant. On the other hand, if thermal expansion of the polyurethane lining layer 5 is smaller than that of the polyurethane lining layer 2, the clearance S becomes wider. Therefore, the clearance S can be kept constant, even if the barrel finishing machine is used for long time under severe conditions by determining the thicknesses of polyurethane lining layers 2 and 5, and the vertical width and the thickness of continuous-porous neoprene rubber plate 7, in order to adjust the effects of thermal expansions of these lining layers 2 and 5 on the clearance S so as to compensate each other. EXAMPLE 2 The embodiment of Fig. 3 is carried out by using an air layer 13, in place of the continuous-porous neoprene rubber plate 7 in Example 1, wherein the air layer 13 is, for example, set as 3∼4 mm thick and 5∼7 cm vertical width. These sizes of thickness and vertical width of air layer may be varied depending upon the condition. Also, the same effect is expected by forming outer wall of polyurethane lining layer 2 in irregularities such as forming concave parts 15 and convex parts 14 on outer face of the polyurethane lining layer 2 as illustrated in Fig. 4, or by forming circular slits 16 (Fig. 5) or longitudinal slits 17 (Fig. 6). The vertical width, and the radial depth of the said irregularities 14, 15, 16, 17 may be chosen to have equivalent absorptive power for thermal expansion of polyurethane lining layer 2 toward the inner wall of stationary barrel 1. Furthermore, if a continuous-porous neoprene rubber plate 18 and an air layer 19 are arranged in combination as shown in Fig. 7, the same effect is expected. Although the present invention has been described with reference to the particular preferred embodiments, it should be understood that various changes and modifications may be made within the scope of the invention as defined in the appended claims.

Claims: A spiral-flow barrel finishing machine comprising a stationary part (3) having a metallic cylindrical stationary barrel (1) equipped with an internal peripheral lining layer (2) in an end portion of the stationary part (3), and a rotary part (6) having a metallic rotational body (4) equipped with a lining layer (5) facing the interior of the stationary part (3), the said parts (3,6) having a common axis (9), there being a radial clearance (S) between an inner peripheral wall of the lining layer (2) of the stationary part (3) and an outer peripheral wall of the lining layer (5) of the rotary part (6), the said end portion of the stationary part (3) being blocked by loose engagement of the rotary part (6) therein, characterised in that a structure to allow for thermal expansion is peripherally arranged between an inner peripheral wall of the metallic stationary barrel (1) and an outer peripheral wall of the internal peripheral lining layer (2), the said structure having an axial height corresponding to the axial height of the said clearance (S) and being easily deformed owing to thermal expansion of the internal peripheral lining layer (2), the said structure comprising an elastic layer (7) or an air layer (13) or a combination of elastic and air layers (18, 19). A spiral-flow barrel finishing machine comprising a stationary part (3) having a metallic cylindrical stationary barrel (1) equipped with an internal peripheral lining layer (2) in an end portion of the stationary part (3), and a rotary part (6) having a metallic rotational body (4) equipped with a lining layer (5) facing the interior of the stationary part (3), the said parts (3,6) having a common axis (9), there being a radial clearance (S) between an inner peripheral wall of the lining layer (2) of the stationary part (3) and an outer peripheral wall of the lining layer (5) of the rotary part (6), the said end portion of the stationary part (3) being blocked by loose engagement of the rotary part (6) therein, characterised in that a structure to allow for thermal expansion is peripherally arranged between an inner peripheral wall of the metallic stationary barrel (1) and an outer peripheral wall of the internal peripheral lining layer (2), the said structure having an axial height corresponding to the axial height of the said clearance (S) and being easily deformed owing to thermal expansion of the internal peripheral lining layer (2), the said structure comprising a continuous-porous material layer (7). A spiral-flow barrel finishing machine comprising a stationary part (3) having a metallic cylindrical stationary barrel (1) equipped with an internal peripheral lining layer (2) in an end portion of the stationary part (3), and a rotary part (6) having a metallic rotational body (4) equipped with a lining layer (5) facing the interior of the stationary part (3), the said parts (3,6) having a common axis (9), there being a radial clearance (S) between an inner peripheral wall of the lining layer (2) of the stationary part (3) and an outer peripheral wall of the lining layer (5) of the rotary part (6), the said end portion of the stationary part (3) being blocked by loose engagement of the rotary part (6) therein, characterised in that a structure to allow for thermal expansion is peripherally arranged between an inner peripheral wall of the metallic stationary barrel (1) and an outer peripheral wall of the internal peripheral lining layer (2), the said structure having an axial height corresponding to the axial height of the said clearance (S) and being easily deformed owing to thermal expansion of the internal peripheral lining layer (2), the said structure comprising irregularities (14,15,16,17) which are formed on the outer wall of the internal peripheral lining (2) and facing the inner wall of the metallic stationary barrel (1). A spiral-flow barrel finishing machine as claimed in any preceding claim, wherein the internal peripheral lining layer (2) is made of polyurethane. A spiral-flow barrel finishing machine as claimed in any preceding claim, wherein the axial height of the said structure is about 3 times the axial height of the clearance (S).

Inventors: FUJISHIRO AKIHITO, IZUHARA KATSUHIRO, KOBAYASHI HISAMINE, FUJISHIRO, AKIHITO, IZUHARA, KATSUHIRO, KOBAYASHI, HISAMINE
Applicants: TIPTON CORP, TIPTON CORP.
Application year: 1997
Main classification: B24B31
IPC codes: B24B31