Abstract:
There is provided a fluid supply mechanism that, when a circular saw blade having a thick boss type base is used, can achieve lubrication and/or cooling of the circular saw blade by performing excellent mist supply. 
     The fluid supply mechanism includes a sleeve  24  with a required length that is attached to a rotary shaft  22,  a required number of doughnut-like shims  26  attached to the sleeve  24  and a rotary tool  10  which is attached to the sleeve  24  and is clamped and fixed by the shims  26  from both sides. A fluid is transferred by pressure from gutter-like passages  30  formed on an inner periphery of the sleeve  24  via through holes  32  formed in the sleeve  24  in the radial direction, the fluid is transferred by pressure to passages  34  provided on inner peripheral faces of the shims  26  and gutters  38  formed to extend in the radial direction on both sides or one sides of the shims  26,  and the fluid is supplied to the rotary tool  10  to lubricate and/or cool the rotary tool  10  during machining a work.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a fluid supply mechanism for a rotary tool. In particular, the present invention relates to a fluid supply mechanism that (1) can adequately supply a fluid, such as lubricant, during machining a work and that (2) can successfully cool and/or lubricate the rotary tool, even if the thickness of a boss of the rotary tool attached to a cutting equipment is larger than that of a base provided with teeth along an outer periphery thereof. 
       BACKGROUND ART 
       [0002]    A rotary tool, such as a circular saw blade, is attached to a rotary shaft of a circular sawing machine and rotated at high speed. However, there is the disadvantage that the temperature of the rotary tool rises abnormally due to friction during cutting a work, and a base or teeth thereof are broken or distorted to reduce its life. Therefore, during machining a work, a fluid, such as lubricant or water, is supplied to the rotary tool to lubricate and/or cool the same. When the fluid is directly supplied to the rotary tool in this manner, lubricating effect or cooling effect becomes large, but there is contamination of the work during machining and a large consumption of the fluid is not economical. 
         [0003]    Therefore, a technique to pneumatically and forcibly supply a fluid is practically used. For example, a fluid, such as lubricant, is pneumatically supplied from the rotary shaft to the rotary tool via fluid passages provided in shims which clamp the rotary tool. If this technique is adopted, since it is made possible to supply a small amount of fluid, such as lubricant, the contamination of work and the amount of fluid used can be kept at a minimum. Also this technique is effective because of its sufficient lubricating/cooling capacity. 
         [0004]    The present invention relates to an extremely-effective fluid supply mechanism for a rotary tool having a thick boss that cannot sufficiently attain lubricating and cooling effects, while the mechanism basically adopting the configuration of the invention disclosed in Publication of Japanese unexamined patent application No. 2004-98188 (Literature 1). Therefore, in order to understand the present invention, it is quite effective to know detailed construction of the invention mentioned in the Literature 1. Then, with reference to  FIGS. 13 to 21 , the invention of the Literature 1 where a rotary tool having a thick boss is applied will be explained. Incidentally, though exemplified by a circular saw blade  10 , the rotary tool is not limited thereby. 
         [0005]      FIG. 13  shows a planar surface of the circular saw blade  10 , where a circular opening  14  with a required diameter is formed in the center of a base  12  with an entirely even thickness formed in a disc shape. A sleeve (not shown) provided on a rotary shaft of a circular saw unit is inserted into the circular opening  14 . Teeth  16 , each of which a chip is bonded, are provided on the outer periphery of the base  12  at required pitches in the circumferential direction thereof. Incidentally, a pair of notches provided on the circular opening  14  in a diametrical direction is key slots  18 . These are for inserting keys ( FIG. 1 ) that fix the circular saw blade  10  to the sleeve of the rotary shaft at a predetermined position. In this circular saw blade  10 , as shown in  FIG. 14  of its side view, the base  12  has an entirely even thickness, so that said saw blade  10  is referred to as isothick type base. 
         [0006]      FIG. 15  shows the circular saw blade  10  used in the fluid supply mechanism of the present invention. In this circular saw blade  10 , the thickness of a boss  20  into which the rotary shaft being inserted is set larger than that of the outer periphery of the base  12 . The boss  20  with such a large thickness endures heavy cutting of a work, and therefore it is very useful for certain kinds of target works. In the present invention, this is referred to as the circular saw blade  10  having a thick boss type base (or a thick boss). 
         [0007]    Next, the case where the circular saw  10  having the thick boss type base shown in  FIG. 15  is used in the fluid supply mechanism of the Literature 1 will be explained with reference to  FIGS. 17 and 18 . A sleeve  24  with a required length is attached to the rotary shaft  22  of the circular saw unit, and the circular saw blade  10  is attached to the sleeve  24  through the circular opening  14 . A required number of doughnut-like shims  26  are also attached to the sleeve  24  in the axial direction thereof to clamp and fix the boss  20  of the circular saw blade  10  from both sides. 
         [0008]    Incidentally, a plurality of circular saw blades  10  are often attached on the outer periphery of the sleeve  24  in the axial direction at intervals corresponding to the thickness of the shim  26  to make up a so-called gang saw. However, only one circular saw blade  10  may be used. All the circular saw blade  10 , the shims  26  and the sleeve  24  are fixed at predetermined positions in their peripheral directions by forcibly inserting rectangular keys  28  with required lengths into the key slots  18  of the circular opening  14 . 
         [0009]    Air including lubricant, coolant or the like is supplied to the sleeve  24  and the shims  26  under pressure so that the base  12  of the circular saw blade  10  is supplied with the lubricant, coolant or the like. That is, as shown in  FIG. 20 , six gutter-like passages  30  are formed, for example, at every central angle of 60° on the inner surface of the sleeve  24  so as to extend in the axial direction. Also, through holes  32  are provided at predetermined intervals in the outer surface of the sleeve  24  to be communicated to the gutter-like passages  30  in the radial direction. These through holes  32  are also correspondingly communicated to passages  34  formed on the inner surface of the shim  26  that will be explained later. Incidentally, in  FIG. 20 , two key slots  36  formed on the outer surface of the sleeve  24  in the axial direction are for inserting the keys  28 . 
         [0010]    As shown in  FIG. 19 , six passages  34  (explained above) are formed on the inner surface of the doughnut-like shim  26  so as to extend in the axial direction at every central angle of 60°. Also, gutters  38  corresponding to the respective passages  34  in a communicated manner are provided on both sides of the shim  26  (six in  FIG. 19 ). Then, the distal end of each gutter  38  in the radial direction opens to the outer surface of the shim  26 . Incidentally, key slots  40  which correspond to the key slots  36  of the sleeve  24  are formed on the inner surface of the shim  26 . 
         [0011]    The circular saw blades  10  having an isothick type base shown in  FIG. 13  are assembled by using the sleeve  24  and the shims  26  as shown in  FIG. 21 . That is, a required number of circular saw blades  10  are attached to the sleeve  24 , and the key slots  36  of the sleeve  24 , the key slots  18  of the circular saw blades  10  and the key slots  40  of each shim  26  are correspondingly aligned with one another. Then, by inserting the keys  28  forcibly into these key slots, the sleeve  24 , the circular saw blades  10  and the shims  26  are fixed at their predetermined positions. Also, the through holes  32  of the sleeve  24  are correspondingly communicated to the passages  34  of the shims  26 . 
         [0012]    Next, in  FIG. 21 , when, for example, air including lubricant, is transferred under pressure by a pressure feed mechanism (not shown) from one end portion of the sleeve  24  to the gutter-like passages  30 , the air including lubricant is supplied to the base  12  of each circular saw blade  10  via the passages  30 →the through holes  32  of the sleeve  24 →the passages  34  of the shims  26 →the gutters  38  of each shim  26 . At this time, the circular saw blades  10  are rotating at high speed so that the lubricant is centrifugally spread in the form of mist from the gutters  38  of the shims  26 , and diffusely supplied up to the distal ends of the bases  12 . Thereby, the bases  12  of the circular saw blades  10  are sufficiently lubricated and cooled. 
       Technical Problem 
       [0013]    As explained above, according to the mist supply mechanism of the Literature 1, it is possible to supply a fluid, such as lubricant, very effectively to the circular saw blade  10  having an isothick type base shown in  FIGS. 13 and 14 . However, in the circular saw blade  10  having a thick boss type base shown in  FIGS. 15 and 16 , as known from  FIG. 18 , the gutters  38  of the shim  26  open away from the base  12 . Therefore, the lubricant from the gutters  38  is released to a position away from the base  12 , and there arises the drawback that the fluid cannot sufficiently be supplied to the teeth  16  or the base  12  of the circular saw blade  10  when a work  42 , such as wood, is cut. 
         [0014]    For this reason, in order to lubricate and/or cool the base  12  sufficiently with lubricant or the like, for example, a highly-concentrated fluid including a lot of lubricant must be adopted. In this case, however, there are such defects as increase in cost for lubricant and deterioration in working environment. 
         [0015]    Therefore, an object of the present invention is to provide a fluid supply mechanism which can achieve lubrication and/or cooling of the circular saw blade by performing excellent fluid supply, when using a circular saw blade having a thick boss type base, without having to increase in concentration of lubricant contained, and without having negative influences on cost and environment. 
       Solution to Problem 
       [0016]    In order to overcome the problems and achieve the desired object, a fluid supply mechanism for a rotary tool according to the present invention comprises: a required number of shims attached directly or via a sleeve on an outer peripheral surface of a rotary shaft; and a rotary tool of which the both sides are fixed and clamped by the shims and which is attached, similarly to the shims, to the rotary shaft, wherein passages for fluid supply of the shims communicated to passages for fluid supply formed in the rotary shaft or the sleeve are extended from an inner peripheral surface side of the shims in the outer peripheral direction, at the same time, terminal ends of the passages for fluid supply of the shims are formed outwards in radial direction of the shims and a fluid is transferred by pressure from outside via the passages for fluid supply formed in the rotary shaft or the sleeve, and the fluid is supplied from the terminal ends of the passages for fluid supply of the shims to the rotary tool so as to cool and/or lubricate the rotary tool during machining a work, characterized in that terminal ends of the passages for fluid supply of the shims which extend outward in radial direction are positioned at a near side of outer peripheral edges of the shims. Incidentally, the term “shim” here should be broadly interpreted, and the term indicates a wide variety of disc-like parts for clamping and fixing the rotary tool, including a so-called flange for supporting the rotary tool on one side. Also, the term “fluid” indicates gas mixed with mist or droplets, or liquid itself. 
       Advantageous Effects of Invention 
       [0017]    Even for a circular saw blade having a thick boss type base, the conventional fluid supply mechanism disclosed in the Literature 1 can be utilized as it is only by replacing the shims of the conventional fluid mechanism with the shims of the present invention. As a result, it is possible to avoid the influences on cost and working environment. Incidentally, the circular saw blade having a thick boss type base has improved rigidity around the teeth as compared with the circular saw blade having an isothick type base, and therefore the thickness of the teeth of the former can be reduced. Accordingly, cutting power, cutting scraps and powder dust are reduced, and improvement in work yield can be expected. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0018]      FIG. 1  is a cross-sectional half plan view of a fluid supply mechanism according to a first embodiment of the present invention; 
           [0019]      FIG. 2  is a vertically-sectional half side view of the fluid supply mechanism according to the first embodiment; 
           [0020]      FIG. 3  is a cross-sectional half plan view of a fluid supply mechanism according to a second embodiment; 
           [0021]      FIG. 4  is a vertically-sectional half side view of the fluid supply mechanism according to the second embodiment; 
           [0022]      FIG. 5  is a cross-sectional half plan view of a fluid supply mechanism according to a third embodiment; 
           [0023]      FIG. 6  is a vertically-sectional half side view of the fluid supply mechanism according to the third embodiment; 
           [0024]      FIG. 7  is a perspective view of a shim used in a fourth embodiment; 
           [0025]      FIG. 8  is a perspective view of a main portion of a rotary shaft used in the fourth embodiment; 
           [0026]      FIG. 9  is a vertically-sectional half side view of a fluid supply mechanism according to the fourth embodiment; 
           [0027]      FIG. 10  is a perspective view of a shim used in a fifth embodiment; 
           [0028]      FIG. 11  is a perspective view of a mail portion of a rotary shaft used in the fifth embodiment; 
           [0029]      FIG. 12  is a vertically-sectional half side view of a fluid supply mechanism according to the fifth embodiment; 
           [0030]      FIG. 13  is a plan view of a circular saw blade having an isothick type base; 
           [0031]      FIG. 14  is a vertically-sectional side view of the circular saw blade shown in  FIG. 13 ; 
           [0032]      FIG. 15  is a plan view of a circular saw blade having a thick boss type base; 
           [0033]      FIG. 16  is a vertically-sectional side view of the circular saw blade shown in  FIG. 15 ; 
           [0034]      FIG. 17  is a cross-sectional half plan view of a conventional fluid supply mechanism used for the circular saw blade having a thick boss type base; 
           [0035]      FIG. 18  is a vertically-sectional half side view of the fluid supply mechanism shown in  FIG. 17 ; 
           [0036]      FIG. 19  is a perspective view of a shim used in the conventional fluid supply mechanism; 
           [0037]      FIG. 20  is a perspective view of a sleeve used in the conventional supply mechanism; and 
           [0038]      FIG. 21  is a vertically-sectional half side view of the conventional fluid supply mechanism used for the circular saw blade having an isothick type base. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0039]    Preferred embodiments of a fluid supply mechanism for a rotary tool according to the present invention will be explained with reference to the accompanying drawings. Incidentally, the embodiments are assumed to be used for the circular saw blade  10  having a thick boss type base shown in  FIG. 16 . Furthermore, the basic configuration of the fluid supply mechanism is as described with reference to  FIGS. 17 to 21 , and therefore the same reference numerals as the abovementioned numerals are denoted to corresponding members, and only configurations specific to the present invention will mainly be described. 
       First Embodiment 
       [0040]      FIG. 1  is a cross-sectional half plan view of a fluid supply mechanism according to a first embodiment, and  FIG. 2  is a vertically-sectional half side view of the fluid supply mechanism. The diameter of a shim  26  in this embodiment is set slightly larger than that of the boss  20  of the circular saw blade  10 . Then, terminal ends  38   a  formed outwards in radial direction on the gutters  38  which are provided on both faces of the shim  26  are positioned at a near side of the outer peripheral edge of the shim  26  and beyond the outer diameter of the boss  20  of the circular saw blade  10 . That is, the terminal ends  38   a  of each gutter  38  do not open beyond the outer periphery of the shim  26  but open beyond the outer diameter of the boss  20  of the circular saw blade  10 . Also, the terminal ends  38   a  of the gutters  38  are obliquely curved so that the terminal ends  38   a  are directed to the base  12  of the circular saw blade  10  when the circular saw blade  10  are clamped and fixed by the shims  26  from both sides. 
         [0041]    Since such a configuration is adopted, when, for example, air including lubricant is transferred by pressure, the air is guided toward the base  12  by the terminal ends  38   a  of the gutters  38 . Thus, by high-speed rotation of the circular saw blade  10 , the lubricant is effectively supplied to the base  12 . That is, the conventional defect that the fluid cannot effectively be supplied, which has been described with reference to  FIG. 18 , is eliminated. 
       Second Embodiment 
       [0042]      FIG. 3  is a cross-sectional half plan view of the fluid supply mechanism according to a second embodiment, and  FIG. 4  is a vertically-sectional half side view of the fluid supply mechanism. The diameter of a shim  26  in this embodiment is set approximately equal to or slightly smaller than that of the boss  20  of the circular saw blade  10 . Furthermore, notches  44  recessed in the radial direction are provided on the outer periphery of the thick boss  20  at positions corresponding to the terminal ends  38   a  of the gutters  38 . Then, the terminal ends  38   a  formed outwards in radial direction on the gutters  38  which are provided on both faces of the shim  26  are positioned at a near side of the outer peripheral edge of the shim  26 . That is, the terminal ends  38   a  of each gutter  38  do not open beyond the outer periphery of the shim  26  but open at the positions of the notches  44  provided on the outer periphery of the boss  20  of the circular saw blade  10 . Also, the terminal ends  38   a  of the gutters  38  are obliquely curved so that, when the circular saw blade  10  is clamped and fixed by the shims  26  from both sides, the fluid released from the terminal ends  38   a  can be directed to the base  12  that is continuous with the notches  44  of the circular saw blade  10 . Thereby, when, for example; air including lubricant is transferred by pressure, the air is guided toward the base  12  by the terminal ends  38   a  of the gutters  38 , and the lubricant is effectively supplied to the base  12  by high-speed rotation of the circular saw blade  10 . 
       Third Embodiment 
       [0043]      FIG. 5  is a cross-sectional half plan view of a fluid supply mechanism according to a third embodiment, and  FIG. 6  is a vertically-sectional half side view of the fluid supply mechanism. In this embodiment, the relationship in size between the shim  26  and the boss  20  of the circular saw blade  10  and the shape of the gutters  38  formed on the shim  26  are the same as those in the second embodiment. However, the notches  44  shown in the second embodiment are not formed on the boss  20 . 
         [0044]    Further, slits  46  extending by a required length outwards in the radial direction from origins positioned slightly inside the outer periphery of the boss  20  are formed in the base  12  of the circular saw blade  10  so as to pass through the base  12 . The number of slits  46  corresponds to the number of gutters  38  formed on the shim  26 , and in this embodiment, it is six. Then, the terminal ends  38   a  of the gutters  38  on the shim  26  are correspondingly positioned at origins (initial ends) of the slits  46 . Thereby, the air including lubricant transferred by pressure through the gutters  38  is supplied from the terminal ends  38   a  thereof toward the slits  46  of the circular saw blade  10 , and thus lubrication and/or cooling of the base  12  is effectively achieved. Incidentally, this embodiment is applicable not only to the circular saw blade  10  having a thick boss type base but also to the circular saw blade having an isothick type base. 
       Fourth Embodiment 
       [0045]    A fourth embodiment in  FIGS. 7 to 9  is different from the first to third embodiments in that no sleeve is required. The rotary shaft  22  in  FIG. 8  is provided, for example, in a circular saw machine, and a fluid pressure feed unit (not shown) is coupled to the rotary shaft  22 , so that a fluid, such as lubricant, can be transferred by pressure to the rotary shaft  22 . 
         [0046]    That is, a fluid passage  52  with a required diameter that extends in an axial direction thereof is formed at the center of the rotary shaft  22 . The fluid passage  52  is closed at one end of the rotary shaft  22  to form a so-called blind hole. And, an open end of the fluid passage  52  is coupled to the fluid pressure feed unit via, for example, a rotary seal joint. Furthermore, through holes  58  communicating to the fluid passage  52  in the radial direction and opening on the outer periphery of the rotary shaft  22  are provided in the rotary shaft  22 . In this case, six vertical gutters  56  extending in the axial direction, for example, at every central angle of 60°, are formed on the outer periphery of the rotary shaft  22  such that the through holes  58  correspondingly open in each vertical gutter  56 . Incidentally, the reference numeral  54  in  FIG. 8  denotes a key slot, and the key slots  54  are aligned with the key slots  40  of the shim  26  that are described later to position and fix the circular saw blade  10  using the keys  28 . 
         [0047]    Next, a shim  26  shown in  FIG. 7  shares a basic structure with the shims in the first embodiment shown in  FIGS. 1 and 2 . However, the passages  34  formed on the inner surface of the shim  26  in the first embodiment are not provided in the mechanism of the fourth embodiment. That is, gutters  38  are formed on both sides of the shim  26  at predetermined intervals, for example, at every central angle of 60° in a circumferential direction of the shim  26 . Here, the terminal ends  38   a  of the gutters  38  at an outward position in the radial direction are positioned at a near side of the outer peripheral edge of the shim  26  and beyond the outer diameter of the boss  20  of the circular saw blade  10 . Therefore, the configuration of the terminal ends  38   a  of the gutters  38  is the same as that of the shim  26  shown in the first embodiment. 
         [0048]    A state where the circular saw blades  10  having a thick boss type base being attached to the rotary shaft  22  using the shims  26  is shown in  FIG. 9 . That is, the shim  26 , the circular saw blade  10  having a thick boss type base, the shim  26 , the circular saw blade  10  having a thick boss type base, . . . are sequentially attached to the rotary shaft  22 , and the circular saw blades  10  are clamped and fixed by these shims  26  from both sides. Incidentally, the key slots  54  of the rotary shaft  22 , the key slots  40  of the shims  26  and the key slots  18  of the circular saw blades  10  are aligned in the axial direction, then the keys  28  are inserted into these key slots, and thus, as shown in  FIG. 9 , the through holes  58  of the rotary shaft  22  and the gutters  38  of the shims  26  are aligned with each other in a communicated manner. 
         [0049]    Then, a fluid, for example, lubricant, is supplied under pressure by a fluid pressure feed unit (not shown) to the fluid passage  52  of the rotary shaft  22 , the lubricant is supplied to the bases  12  of the circular saw blades  10  through the fluid passage  52  of the rotary shaft  22 →the through holes  58 →the vertical gutters  56 →the gutters  38  of the shims  26 . Incidentally, the gutters  38  of the shims  26  are closed by the bosses  20  of the circular saw blades  10  when the circular saw blades  10  are clamped and fixed by the shims  26 . However, as described above, the terminal ends  38   a  of the gutters  38  are present at positions beyond the outer diameter of the bosses  20 . Therefore, the lubricant transferred by pressure is effectively supplied from the terminal ends  38   a  to the bases  12  of the circular saw blades  10  to lubricate and/or cool the circular saw blades  10  effectively. 
       Fifth Embodiment 
       [0050]    A fifth embodiment in  FIGS. 10 to 12  as well as the fourth embodiment relates to a fluid supply mechanism that requires no sleeve. The rotary shaft  22  ( FIG. 11 ) used in this fifth embodiment has the same configuration as that shown in  FIG. 8  in the fourth embodiment, and therefore explanation thereof will be omitted. The shim  26  is as shown in  FIG. 10 . 
         [0051]    That is, the shim  26  has (1) first through holes  60   a  opening on the inner peripheral face and extending in the radial direction, and (2) second through holes  60   b  opening on both sides or one side of the shim  26  and communicated to the first through holes  60   a  inside the shim  26  in an intersecting manner. Thus, the first through holes  60   a  and the second through holes  60   b  make up fluid supply passages  60 . Incidentally, the first through holes  60   a  and the second through holes  60   b  are formed, for example, in six pairs at predetermined intervals at every central angle of 60° in a circumferential direction of the shim  26 . Therefore, the fluid supply passage  60  comprising the first through hole  60   a  and the second through hole  60   b  is formed in a T shape or an L shape inside the shim  26  as shown in  FIG. 12 . 
         [0052]    Also in this case, terminal ends  60   c  of the second through holes  60   b  opening on both sides or one side of the shims  26  are positioned at a near side of the outer peripheral edge of the shim  26 . Also, it is preferred that the terminal ends  60   c  face the outer peripheral edge of the boss  20  of the circular saw blade  10  having a thick boss type base, or they are positioned beyond the outer peripheral edge thereof. 
         [0053]    By adopting such a configuration, in the fifth embodiment, when the shims  26  and the circular saw blades  10  are sequentially attached to the rotary shaft  22  and fixed by a nut at an axial end or the like, the configuration shown in  FIG. 12  is obtained. That is, when, for example, lubricant is transferred as the fluid by pressure to the fluid passage  52  of the rotary shaft  22 , the lubricant is supplied to the bases  12  of the circular saw blades  10  via the through holes  58 →the vertical gutters  56 →the first through holes  60   a  of the shims→the second through holes  60   b.