FIELD OF THE INVENTION
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The present invention relates to a flour roll mill.
BACKGROUND OF THE INVENTION
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A conventional roll mill will be described with reference to Figures 6 and 7. Figures 6 and 7 illustrates what is called duplex roll mill in which the interior of a single frame 113 is divided into two sections 115 and 116 by partition plates 114 and a pair of rolls 101 and 102 are provided symmetrically in each of the sections 115 and 116. Usually, the roll 102 serving to rotate at low speed is arranged nearer to the partition wall 114. The high-speed rotation roll 101 is rotatably supported by a fixed bearing 103 and the low-speed rotation roll 102 is rotatably supported by a movable bearing 104. Each of the movable bearings 104 is pivotable about a fulcrum pin 105 so that the gap between the rolls 101 and 102 can be adjusted by a roll gap adjusting means.
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More specifically, a shaft of a roll gap adjusting handle 106, which is provided outside the frame 113, and a connecting rod 107 connected with the movable bearing 104 are connected to each other by means of an arm 108. Further, a pin 109 is provided at a position on the arm 108 nearer to the connecting rod 107 than the longitudinally central position of the arm 108 so as to serve as a fulcrum about which the arm 108 pivots, so that the movable bearing 104 is made to approach to/to be separated from the fixed bearing 103 by the operation of the handle 106, thereby adjusting the gap between the rolls 101 and 102.
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However, in case of exchanging the rolls 101 and 102 due to wearing-out thereof etc., it is required to detach the adjusting means attached to both left and right side walls 110, 110, resulting in the troublesome exchanging operation.
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On the other hand, recently, the roll gap adjustment has a tendency to be performed not by the handle 106 but by a microcomputer-controlled motor or the like (see Japanese Patent Examined Publication No. 60-52862 for example). However, the technique for facilitating the exchange of the rolls has not been developed so much. For example, in an apparatus disclosed in Japanese Patent Examined Publication No. 60-52862 as well, only after the connecting rod serving to connect the both bearings with each other as the roll gap adjusting means is detached, the rolls can be exchanged by being lifted up at their both ends by means of a winch or the like, resulting in the complicated exchanging operation.
OBJECT AND SUMMARY OF THE INVENTION
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The present invention has been made to eliminate at least part of the above problems, and an object thereof is to provide a flour roll mill in which a roll can be demounted/mounted more easily without removing roll gap adjusting means.
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To this end, there is provided according to the present invention a flour roll mill having at least a set of component parts comprising a fixed bearing secured to a frame at a position close to an opening of a roll entrance notched portion formed in each of opposite side walls, a movable bearing secured to the frame at a position more remote from the opening than the fixed bearing, and a pair of rolls including a high speed roll rotatably supported by the fixed bearing and a low speed roll rotatably supported by the movable bearing so as to be rotated reversely to the high speed roll at a peripheral speed lower than that of the high speed roll, the roll mill comprising: roll gap coarse adjustment means for coarsely adjusting a gap between the rolls; and a roll gap fine adjustment means for finely adjusting the gap between the rolls, wherein a support frame for a bearing body of the movable bearing is separable into first and second parts so that the first part closer to the fixed bearing than the second part can be separated to be attached and detached at a side of the fixed bearing, wherein the coarse adjustment means comprises an eccentric serving to coarsely adjust the gap between the rolls, and means, for driving the eccentric, which is connected with one end portion of the second part pivotally supported by the side wall, and wherein the fine adjustment means comprises a roll gap fine adjustment shaft engaged with the other end portion of the second part, a roll gap fine adjustment eccentric connected with the fine adjustment shaft through a spring and provided on one side of the movable bearing opposite to the fixed bearing, and means for driving the eccentric.
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It is preferred that the coarse adjustment eccentric driving means comprises an arm connected at one end thereof with a main shaft of the coarse adjustment eccentric, and an air cylinder device connected with the other end of the arm.
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Further, it is preferred that the fine adjustment eccentric driving means comprises a worm wheel fixedly mounted on a main shaft of the fine adjustment eccentric, and a worm meshing with the worm wheel and actuated by a motor.
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In the flour roll mill constructed as described above, in case of exchanging the rolls, the fixed bearing is removed from the side wall and then the high speed roll supported by the fixed bearing is taken out of the mill through the opening of the roll entrance notched portion together with the fixed bearing by means of a winch or the like. Subsequently, after the first part of the support frame for the bearing body of the movable bearing located on the side closer to the fixed bearing than the second part is separated from the second part, the low speed roll is taken out of the mill through the opening together with the bearing body or the bearing member. Then, a new low speed roll for renewal is inserted through the opening together with the bearing body so as to be mounted on the second part of the support frame for the bearing body of the movable bearing, and the first part of the movable bearing which has been separated is integrated with the second part. Subsequently, a new high speed roll for renewal is inserted through the opening together with the fixed bearings so as to secured to the side walls. It is noted that, on the occasion of roll exchange, either of the high speed roll and the low speed roll may be renewed alone.
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As described above, in the flour roll mill according to the present invention, since the roll gap coarse adjustment means is provided at a position more remote from the opening of the roll entrance notched portion, the roll gap coarse adjustment means can be kept out of the way even when the roll is taken in and out by means of a winch or the like and, in addition, it is possible to dispose a control unit or the like for example, in the vicinity of the fixed bearing.
BRIEF DESCRIPTION OF DRAWINGS
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- Figure 1 is a partially-sectioned side view of a flour roll mill according to a preferred embodiment of the present invention;
- Figure 2 is an enlarged view of a part of the roll mill shown in Figure 1;
- Figure 3 is a plan view of a part of the roll mill shown in Figure 2;
- Figure 4 is a perspective view of a part of the roll mill shown in figure 2;
- Figure 5 is an enlarged sectional view of a part of a flour roll mill according to another preferred embodiment of the present invention;
- Figure 6 is a front view of a conventional flour roll mill; and
- Figure 7 is a partly broken side view of the roll mill shown in Figure 6.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
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Figure 1 to 4 illustrate a flour roll mill according to a preferred embodiment of the present invention. Referring to these drawings, a frame 1 constituting a flour roll mill has a front wall 1a and a rear wall 1b. Each of the front and rear walls 1a and 1b is formed therein with an opening 4 through which a high speed roll 2 and a low speed roll 3 to be rotated reversely to the roll 2 at a peripheral speed lower than that of the roll 2 are taken in/out of the mill, and a roll cover 5 is removable attached to the opening 4. In Figure 1, reference numerals 6a and 6b denote side walls on this or front side and back side of the frame 1, respectively. It is noted that the side walls 6a and 6b will be generally represented by a reference numeral 6, hereinafter. The both side walls 6 of the frame 1 are formed therein with roll entrance notched portions 7 in correspondence with the respective openings 4. The roll entrance notched portion 7 is made wider as getting close to the opening 4 on each side. Further, the notched portion 7 is horizontally elongated toward the central portion of the roll mill until it reaches a position indicated by a reference numeral 7a. Movable bearings 8 are each arranged in the roll entrance notched portion 7 at a position close to a closed end portion 7a of the roll entrance notched portion 7, and fixed bearings 9 are each arranged therein at a position close to the opening 4. The low speed rolls 3 and the high speed rolls 2 are rotatably supported by the movable bearings 8 and the fixed bearings 9, respectively. A cover plate 48 is provided between each fixed bearing 9 and the movable bearing 8 associated therewith.
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More specifically, each of the fixed bearings 9 is secured to a mount 54 on the side wall 6 of the frame 1 by means of bolts. A support frame for the bearing body or a bearing member 8e of the movable bearing 8 is composed of a frame portion 8b and a separate case 8a constituting about a little under half part of the support frame and located close to the fixed bearing 9. This separate case 8a is detachably fixed to the frame portion 8b of the movable bearing 8 by means of bolts. The support frame portion 8b of the bearing 8 is pivotally mounted at a lower end portion 8c thereof to the side wall 6 through a roll gap coarse or rough adjustment eccentric 10 connected eccentrically with a main shaft 11 which is rotatable about a center axis 11a. The eccentric 10 is driven by a driving means which comprises an arm 12 fixed at one end thereof to the main shaft 11 of the eccentric 10 and a roll gap coarse adjustment air cylinder device 13 having an expansible rod 13a connected with the arm 12 at the tip end thereof. As described in detail in Figures 2 to 4, the support frame portion 8b of the movable bearing 8 is connected at an upper end portion 8d thereof (see Figures 2 to 4) with a roll gap fine adjustment eccentric 14 through disk springs 15, which eccentric 14 is connected to a roll gap fine adjustment eccentric driving means provided at a position on a side of the movable bearing 8 opposite to the fixed bearing 9.
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More specifically, the movable bearing 8 is formed in the upper end portion 8d thereof with a groove 16. A roll gap fine adjustment shaft 17 is engaged in the groove 16 so that it extends substantially horizontally along the groove 16. Further, the fine adjustment shaft 17 is loosely fitted in holes 18a and 19a of a pair of fixing or supporting plates 18 and 19, respectively. This pair of supporting plates 18 and 19 are screwed on two screw rods 20, 20 so as to be fixed to each other. A plurality of disk springs 15, through which the fine adjustment shaft 17 extends, are provided between a large diameter engaging shaft portion 17a formed on the fine adjustment shaft 17 and the supporting plate 18 adjacent to the fixed bearing 9. The upper end portion 8d of the movable bearing 8 is inserted between the engaging shaft portion 17a and the supporting plate 19 close to the central portion of the apparatus so that the groove 16 and the fine adjustment shaft 17 are engaged with each other. The supporting plate 19 is formed with projections 21, 21 at portions thereof where the plate 19 comes in contact with the upper end portion 8d of the movable bearing 8, and the upper end portion 8d of the movable bearing 8 is formed with recesses 22, 22 at portions thereof corresponding to or abutting against the projections 21, 21. Further, several rings 23 are fitted on the shaft 17 so as to be disposed between the upper end portion 8d of the movable bearing 8 and the engaging shaft portion 17a, and the upper end portion of the movable bearing 8 is formed with projections 24 at portions thereof coming in contact with the ring 23, the projections 24 each projecting in the form of a circular arc around the horizontal line.
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Next, the roll gap fine adjustment eccentric driving means will be explained. A gear case 26 and a reversible motor 27 are fixed to a flange wall 25 formed substantially vertically along the center line A of the side wall 6 in such a manner that the motor 27 is located above the gear case 26 (right and left parts divided by the center line A are mirror-symmetrical with respect to the flange wall 25 so that description will be given of only one of them). Within the gear case 26, a worm 28 fixed to the shaft of the motor 27 and a worm wheel 29 meshing with the worm 28 are disposed. The worm wheel 29 is fixedly mounted on a main shaft 14a of the fine adjustment eccentric 14 provided on the gear case 26, and the fine adjustment shaft 17 mentioned before is fixed to an eccentric rod 30 engaged with the eccentric 14. The eccentric rod 30 having a concaved surface of the shape complementary to the shape of the cylindrical peripheral surface of the eccentric 14 is pressed against the peripheral surface of the eccentric 14 due to expansive forces of the disk springs 15.
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A cover 34 encloses the high speed roll 2 and the low speed roll 3 to define a grinding chamber 35. A discharge hopper 32 is formed in the lower portion of the grinding chamber 35 and a lower end of a conveying pipe 33 opens into the discharge hopper 32. A stock supply means 50 is provided above the grinding chamber 35. Namely, a stock supply cylinder 36 formed by a transparent wall is provided in the center of a top wall 1C of the frame 1. The interior space of the stock supply cylinder 36 is divided into two stock supply chambers 38, 38 by means of a partition plate 37 so as to supply the stock to two pairs of rolls (2, 3: 2, 3). An upper limit level sensor 39 and a lower limit level sensor 40 are provided separately in the stock supply chambers 38, 38, which sensors 39 and 40 are connected to a control unit 52. A feed hopper 41 is formed below each supply chamber 38, and two feed rolls 42 and 43 driven by a motor (not shown) are provided in parallel with each other at the lower end of the feed hopper 41. A feeder gate plate 44 is provided in the vicinity of the feed roll 42 such as to be pivotal about a pivot pin 44a. The feeder gate plate 44 is pivoted about the pivot pin 44a by means of a feeder gate opening/closing cylinder 45 and a feeder gate adjusting device 46 so as to moved away from close to the feed roll 42, thereby opening/closing the flow path or passage defined between the feed roll 42 and the gate plate 44 as well as adjusting the opening (size) of the passage. The feeder gate plate 44 may be provided in association with the feed roll 43 instead of being provided in association with the feed roll 42. A guide chute 47 is provided contiguously to the feed rolls 42, 43 so as to be extended substantially vertically. The lower end of the guide chute 47 opens in the grinding chamber 35 at a position above the gap between the high speed roll 2 and the low speed roll 3.
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Now, description will be given below of practical action and operation of an embodiment of the flour roll mill 60 having the above structure. As a main motor (not shown) is started to drive to rotate the high speed roll 2 and the low speed roll 3, the control unit 52 produces an electric signal to expand the rod 13a of the roll gap coarse adjustment cylinder device 13 so that the arm 12 and the main shaft 11 are pivoted about the center axis 11a of the main shaft 11 until they are brought into a state indicated by two-dot chain lines in Figure 2. In this case, owing to an eccentric rotation of the roll gap coarse adjustment eccentric 10 which is eccentric with respect to the main shaft 11, the movable bearing 8 is moved largely in the direction of an arrow B so as to approach the fixed bearing 9, thus performing the primary adjustment or the coarse adjustment of the gap between the rolls 2 and 3. During this movement of the movable bearing 8 in the direction B, the movable bearing 8 is pivoted or swung about fulcrums constituted by the projections 24 and the recesses 22 of the upper end portion 8d of the movable bearing 8 and the projections 21 of the supporting plate 19. Upon completion of the coarse adjustment, the motor 27 is then started to make rotate the fine adjustment eccentric 14 which is eccentric with respect to the main shaft 14a about the center axis 14b of the main shaft 14a. With the rotation of the eccentric 14, the large diameter shaft portion 17a of the fine adjustment shaft 17 acts to move the supporting plate 18 in the direction of an arow C through the disk springs 15. This movement of the supporting plate 18 in the direction C causes the supporting plate 19 united with the plate 18 through the rods 20 to be moved in the direction C as well. Therefore, the recesses 22 of the upper end portion 8d of the movable bearing 8 are pushed by the projections 21 of the supporting plate 19 so that the upper end portion 8d is moved in the direction C. As a result, the low speed roll 3 supported by the movable bearing 8 is pivoted in the direction of approaching the high speed roll 2, thereby setting the gap between the rolls 2 and 3 at a predetermined magnitude.
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After the fine adjustment is performed as secondary adjustment in the described manner, the stock to be ground such as wheat, rice or the like is supplied into the stock supply chamber 38 up to the level regulated by the upper limit level sensor 39. Then, the upper limit level sensor 39 detects "the presence of the stock" and hence produces a detection signal. When the control unit 52 receives the detection signal from the upper limit level sensor 39, the feeder gate opening/closing cylinder 45 is driven under the control of the control unit 52 so as to move the feeder gate plate 44 to a position where it opens the passage for the stock. On the other hand, under the control of the control unit 52, the two feed rolls 42, 43 are rotated by force in the direction of arrows D in which the stock is conveyed toward the guide chute 47. The stock is fed into the guide chute 47 at a proper speed depending on the rotational speed of the feed rolls 42, 43 in the direction D while being spread substantially uniformly in the axial direction of the rolls 42, 43. The stock flowing down from the guide chute 47 is subjected to the grinding action while it passes through the gap between the high speed roll 2 and the low speed roll 3, and then dropped down into the discharge hopper 32. The ground stock in the discharge hopper 32 is transported pneumatically to the succeeding step due to an air stream flowing through the conveying pipe 33.
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When the stock in the stock supply chamber 38 is decreased down to the level defined by the lower limit level sensor 40, the lower limit level sensor 40 detects "the absence of the stock". When the control unit 52 receives the detection signal from the lower limit level sensor 40, the feeder gate plate 44 is moved to a position where it closes the passage for the stock and the feed rolls 42, 43 are stopped from rotating under the control of the control unit 52. Further, under the control of the control unit 52, the motor 27 is reversely driven so that the engaging shaft portion 17a of the fine adjustment shaft 17 causes the upper end portion 8d of the movable bearing 8 to move in the direction of an arrow E in which the roll gap is made wider. In addition, the rod 13a of the coarse adjustment cylinder device 13 is contracted to cause the joint end of the arm 12 to be pivoted downwards, so that the lower end portion 8c of the movable bearing 8 is moved in the direction of an arrow F, thereby enlarging the gap between the rolls 2 and 3. In this state, the power source is cut off by an operator of the roll mill 60, so that the main motor (not shown) is stopped.
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Next roll exchanging operation will be explained. In case of exchanging the rolls 2 and 3, a cover (not shown) or the like which is provided outside each side wall 6 of the frame 1 for covering the controlling mechanism is removed (as shown in a half part on the left hand of the center line in Figure 1), and the roll cover 5, and the cover plates 48 forming a part of the side wall 6 and the like are detached to permit the roll entrance notched portions 7 to be exposed. The fixed bearings 9 are first detached from the mounts 54 on the side wall 6, and the high speed roll 2 is taken out of the mill through the opening 4 together with the fixed bearings 9 while being carried by a which or the like at opposite end shaft portions thereof. Then, the support frame for the bearing member 8e of each movable bearing 8 is separated into two parts 8a and 8d, and the lower speed roll 3 is taken out of the mill through the opening 4 with the bearing body or member 8e attached to the roll 3 while being carried by the which or the like in the same manner as described above. In case of mount new rolls 2, 3 for renewal, the low speed roll 3 for renewal to which the bearing body 8e is attached is mounted on the support frame portions 8b of the movable bearings 8 and then the support frame portions 8a and 8b of each movable bearing 8 having been separated from each other are integrated together in the reverse manner to the above case of removal. Subsequently, the high speed roll 2 for renewal which has been mounted on the fixed bearing 9 in advance is inserted through the opening 4 to the predetermined position close to the opening 4 together with the bearing 9, and then the fixed bearing 9 is secured to the mount 54 and the cover and the like are attached finally.
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Figure 5 shows another embodiment in which a roll gap fine adjustment means of a simpler structure is used. In Figure 5, the fine adjustment shaft 17 is engaged in the groove 16 of the upper end portion 8d of the movable bearing 8, and the upper end portion 8d is disposed between a large diameter engaging shaft portion 17b and the disk springs 15. A projection 56 of the large diameter shaft portion 17b of the fine adjustment shaft 17 or of a plate 17b fixed to the shaft 17 is engaged with a recess formed in one of end faces of the upper end portion 8d on the side facing to the fixed bearing 9. Another projection 58 formed on the other end face of the upper end portion 8d on the side opposite to the fixed bearing 9 is pressed in the direction of an arrow C by one end of the disk spring 15 through he rings 23, and the other end of the disk springs 15 is stopped by nuts 50. In the case of this embodiment, whichever the movable bearing 8 is moved in the direction C or E to make narrower or wider the gap between the rolls 2 and 3, the disk springs 15 directly take part in this movement. Furthermore, in this embodiment, the space around the fixed bearing 9 can be opened much more widely than in the case of the aforesaid embodiment so that it becomes easier to take in an out the rolls 2 and 3.
