Abstract:
A fine adjusting method of the feed amount of a boring cutter includes the following steps: a shank body rotates around its axes as the center of a circle to make the cutter tip rotate around its axes as the center of a circle which is apart away from the axes with an offset distance e therebetween so as to change the feed amount. An adjusting device which can achieve the fine adjusting method of the feed amount of the boring cutter includes: a shank body which has a tapered bore, and the axes of the tapered bore is apart away from the axes of the shank body; a rotating cone body which cooperates with the tapered hole; and the rotating cone body is provided with another tapered hole; a changeable cutter holder which is installed in the tapered hole of the rotating cone body; and a drive mechanism which mounts on the shank body and drives the rotating cone body to rotate, therefore makes the changeable cutter holder rotate so as to achieve the micro-feed of the cutter tip.

Description:
BACKGROUND OF THE PRESENT INVENTION  
       [0001]    1. Field of Invention 
         [0002]    The present invention relates to a machining cutting tool, and more particularly to a method for adjusting feed amount of a cutter and an adjusting device thereof, and especially a method for adjusting feed amount of a boring cutter and an adjusting device thereof. 
         [0003]    2. Description of Related Arts 
         [0004]    As we all known, the current available fine adjusting boring cutter bar comprises a shank body having a linear guide track, a moving body engaged with the guide track, a screw stem transmission mechanism, a changeable cutter arbor, a dial for indicating linear feed amount, and a fastening screw, which is called a linear type fine adjusting boring cutter bar, as shown in  FIG. 1 . The moving body is driven by the screw stem transmission mechanism to move along the axis of the screw stem, so that the radial position of the moving body is changed to change the feed amount. In this structure, there are many elements that are hard to be manufactured and are difficult to cooperate with each other. Furthermore, there is a gap between the linear moving elements, so that the precision of the boring hole is affected, if without proper maintenance. In addition, when the moving body is moved for a long distance, the gravity center is shifted largely, so that quick cutting can not be realized. And the screw pitch cannot be small, so that the precision of fine adjustment is restricted. The precision of the fine adjustment of the imported product can be only up to 0.01 mm. 
       SUMMARY OF THE PRESENT INVENTION  
       [0005]    In order to overcome the above mentioned drawbacks, an object of the present invention is to provide a method for adjusting feed amount of a cutter. The method adopts the principle of the Archimedes spiral, wherein the cutter is pushed inwards in a rotary manner to satisfy the machining demand. 
         [0006]    Another object of the present invention is to provide an adjusting device for adjusting feed amount of a cutter, so as to satisfy various work conditions of the boring hole of the hole machining machine. 
         [0007]    Accordingly, in order to accomplish the above object, the present invention provides a method for fine adjusting feed amount of a boring cutter, wherein the cutter bar rotates with an axis of the cutter bar as center of circle for driving a cutter tip to rotate taking a center of circle that has an offset e apart from an axis of the cutter bar, so as to adjust a feed amount of the boring cutter. 
         [0008]    The offset e is obtained by designing an Archimedes spiral taking an axis center of the cutter bar as center and replacing an Archimedes spiral with an approximate arch  α , and the offset between a center of the arch  α  and the axis center of the cutter bar is e. 
         [0009]    The offset e is a real number. 
         [0010]    An adjusting device for adjusting feed amount of a boring cutter, comprising: 
         [0011]    a cutter bar having a first taper hole therein with an axis that is apart from an axis of the cutter bar; 
         [0012]    a rotating taper, engaged with the taper hole of the cutter bar, having a second taper hole provided therein; and 
         [0013]    a driving mechanism mounted on the cutter bar and driving the rotating taper to drive a changeable cutter arbor to rotate so as to adjust feed amount of the cutter. 
         [0014]    The driving mechanism is a turbine and worn transmission mechanism. 
         [0015]    A dial for indicating feed amount of cutter changing in a rotary manner is provided on the worn of the turbine and worn transmission mechanism, so as to obtain accurate feed amount value. 
         [0016]    As adopting the above technique, the boring cutter of the present invention has good linear character and high precision for fine adjusting the feed amount. The precision of the fine adjustment is up to 0.002 mm. The device has many advantages. For example, the elements of the device are simple in shape; the device has rigid structure, and is convenient to operate; due to small shift of the gravity center, the device can be used for quick cutting. The device can satisfy various work conditions of the hole machining machine, such as the boring machine, milling machine, and drilling machine. 
         [0017]    These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0018]      FIG. 1  is a structural schematic view of a prior art of a linear fine adjusting boring cutter bar. 
           [0019]      FIG. 2  is a schematic view of a method for adjusting feed amount of a boring cutter according to a preferred embodiment of the present invention, illustrating the principle of present invention. 
           [0020]      FIG. 3  is a structural schematic view of a fine adjusting device for adjusting feed amount of a boring cutter of example 1 according to the above preferred embodiment of the present invention. 
           [0021]      FIG. 4  is an A-A sectional view of  FIG. 3 . 
           [0022]      FIG. 5  is a sectional view of B direction of  FIG. 3 . 
           [0023]      FIG. 6  is a perspective view of a fine adjusting device for adjusting feed amount of a boring cutter of example 2 according to the above preferred embodiment of the present invention. 
           [0024]      FIG. 7  is a side sectional view of the fine adjusting device for adjusting feed amount of a boring cutter of example 2 according to the above preferred embodiment of the present invention. 
           [0025]      FIG. 8  is an A-A sectional view of  FIG. 7 . 
           [0026]      FIG. 9  is a sectional view of B direction of  FIG. 7 . 
           [0027]      FIG. 10  is a perspective view of a fine adjusting device for adjusting feed amount of a boring cutter of example 3 according to the above preferred embodiment of the present invention. 
           [0028]      FIG. 11  is a perspective view of a fine adjusting device for adjusting feed amount of a boring cutter of example 4 according to the above preferred embodiment of the present invention. 
           [0029]      FIG. 12  is a perspective view of a fine adjusting device for adjusting feed amount of a boring cutter of example 5 according to the above preferred embodiment of the present invention. 
           [0030]      FIG. 13  is a side sectional view of the fine adjusting device for adjusting feed amount of a boring cutter of example 5 according to the above preferred embodiment of the present invention. 
           [0031]      FIG. 14  is an A-A sectional view of  FIG. 13 . 
           [0032]      FIG. 15  is a perspective view of a fine adjusting device for adjusting feed amount of a boring cutter of example 6 according to the above preferred embodiment of the present invention. 
           [0033]      FIG. 16  is a perspective view of a fine adjusting device for adjusting feed amount of a boring cutter of example 7 according to the above preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0034]    Referring to  FIG. 1  of the drawings, a currently available linear fine adjusting boring cutter bar according to a preferred embodiment of the present invention is illustrated, in which the fine adjusting boring cutter bar comprises a shank body  1 ′ having a linear guide track, a moving body  2 ′ engaged with the guide track, a screw stem transmission mechanism  3 ′, a changeable cutter arbor  4 ′, a dial  5 ′ for indicating linear feed amount, a cutter  6 ′ and a fastening screw  7 ′. 
         [0035]    Referring to  FIG. 2  of the drawings, a method for adjusting feed amount of a boring cutter is illustrated. An Archimedes spiral taking the axis center O 1  of the cutter bar as center is designed, and mathematically processed. In a proper angle, such as 48 degree, replace the Archimedes spiral with an approximate arch α. The offset between the center of the arch αO 2  and the cutter bar axis center O 1  is e, which is a real number. When the cutter tip rotates around the center of arch α O 2 , the feed amount of the cutter is adjusted. The linear character of this method is good. When the dial for indicating the feed amount of the cutter is equally divided to 50 parts, the error of each part is less than 0.0005 mm. The arch b is machining circle, and the lines c indicate the position of cutter during rotating process. 
       EXAMPLE 1 
       [0036]    Referring to  FIG. 3 ,  FIG. 4  and  FIG. 5  of the drawings, the fine adjusting device for adjusting feed amount of a cutter is applied to milling machine. The taper shank of the cutter bar  1  is engaged into the taper hole of the main shaft of the milling machine. The cutter bar  1  has a first eccentric taper hole  11  apart from the axis of the cutter bar  1 . In the first eccentric taper hole  11 , a rotating taper  2  is provided between a side cover threadedly connected to the cutter bar  1  and a resilient element  6 . The rotating taper  2  also has a second eccentric hole  21  apart from the axis of the rotating taper  2 . A changeable cutter arbor  8  is provided in the second eccentric hole  21  of the rotating taper  2 . A cutter  81  is mounted on the front of the changeable cutter arbor  8  via a fastening screw  81 . 
         [0037]    A turbine  3  is mounted on the rotating taper  2 , and it also can be directly incorporated onto the outer surface of the rotating taper. A worn  4  is mounted on the cutter bar  1  via a pair of bearing side covers  5 , and is engaged with the turbine  3  so as to drive the rotating taper  2  to rotate. The bearing side cover  5  on one side of the worn has 20 indicating lines marked thereon, and each indicating line indicates that the feed amount changes 0.025 mm. That is to say, when the worn  4  rotates one circle, the feed amount changes 0.5 mm. While fine adjusting, rotate the worn  4 , so that the turbine  3  drives the rotating taper  2  to rotate due to the engagement between the worn  4  and turbine  3 , and further drives the changeable cutter arbor  8  to rotate, so as to fine adjust the cutter tip of the cutter  82 . 
         [0038]    In order to improve the accuracy of indicating lines, the line between the cutter tip of the cutter  82  and the center of the cutter bar  1  is visually vertical to the line between the first eccentric taper hole  11  and the second eccentric taper hole  12 . As shown in  FIG. 5 , the exclusive bar for rotating the worn  4  is put on while fine adjusting, and is taken off while boring. 
         [0039]    This example can also be applied to a boring machine and a drilling machine. The difference is the taper of the taper shank of the cutter bar, because the taper shank has to engage into the taper hole of the main shaft of the boring machine and drilling machine. Other structures are same with the above mentioned structures. 
         [0040]    Adopting the principle and structure of the example, a series of products can be manufactured by changing the transmission ratio of the transmission structure of the turbine and worn, eccentric offset, or the taper shank of the cutter bar  1  for being applied to the boring machine, milling machine, and drilling machine and other hole machining machines. 
       EXAMPLE 2 
       [0041]    Referring to  FIG. 6  through  FIG. 9 , the fine adjusting device for adjusting feed amount of a cutter is applied to a milling machine. The taper shank of the cutter bar  1  is engaged into the taper hole of the main shaft of the milling machine. 
         [0042]    In this example, when the worn  4  rotates one circle, the feed amount change 0.5 mm. The dial  7  for indicating feed amount on the worn  4  has 50 indicating lines marked thereon, and each indicating line indicates that the feed amount changes 0.01 mm. 
         [0043]    In the eccentric taper hole  11  of the cutter bar  1 , the rotating taper  2  having a taper hole  22  therein is mounted between the resilient element  6  and a fastening cover  61  that is threadedly connected with the cutter bar  1 . The axis of the taper hole  22  is coincidence with the axis of the rotating taper. 
         [0044]    An incomplete turbine  31  of the turbine and worn mechanism is mounted on the rotating taper  2 . The two sides of the worn is mounted in the worn hole  12  of the cutter bar  1  via a bearing  51 , a bearing fastener  52  and a bearing fastener with cover  53 . The worn  4  is engaged with the incomplete turbine  31 . 
         [0045]    A dial for indicating feed amount  7  is fixed on one side of the worn  4  and can rotate with the worn  4 . 
         [0046]    A first fastener  91  and a second fastener  92  of a fastening unit  9  are fastened in the fastening hole  13  of the cutter bar via a gasket  93  and a fastening bolt  94 . A fastening arch  95  matched with the outer taper arch of the rotating taper  2  is provided on the first fastener  91  and the second fastener  92  respectively. When the fastening bolt  94  is fastened, the first fastener  91  and the second fastener  92  are close to each other, so that the fastening arches  95  on the first fastener  91  and the second fastener  92  contacts and rotates the outer surface of the rotating taper  2 , so as to fasten the rotating taper. When the fastening bolt  94  is loosened, the first fastener  91  and the second fastener  92  are apart from each other, so that the fastening arches  95  on the first fastener  91  and the second fastener  92  is separated from the outer surface of the rotating taper  2 . The rotating taper  2  is driven to rotate by the worn  4  and the incomplete turbine  31 . 
         [0047]    The changeable cutter arbor  8  is mounted in the taper hole  22  of the rotating taper  2  via a screw  83 , and the cutter  82  is mounted on the changeable cutter arbor  8  via a fastening bolt  81 . 
         [0048]    While fine adjusting, rotate the incomplete turbine  31  engaged with the worn  4  to drive the rotating taper, and further to drive the changeable cutter arbor  8  to rotate, so as to fine adjust the cutter  82 . 
         [0049]    Due to the small range of the fine adjustment, large position shift can be achieved by adjusting the position of the cutter and a plurality of changeable cutter arbor  8  of different sizes (30 mm-120 mm). The cutter  82  is mounted according to the reference surface d, which is very convenient and precise, as shown in  FIG. 9 . 
         [0050]    The shank of the changeable cutter arbor  8  adopts the taper of 1:20, and comprises a rotation proof flat tenon. 
       EXAMPLE 3 
       [0051]    The example 3 is applied to a machining center machine. As shown in  FIG. 10 , the difference from the example 2 is that the taper shank of the cutter bar is engaged with the taper hole of the axis of the machining center (ISO 7:24 50); and both linear and rotation way to change the feed amount are adopted. 
         [0052]    The cutter  82  is threadedly connected with the changeable cutter arbor  8 . A dial for indicating linear feed amount  84  is provided at the threaded connection position of the changeable cutter arbor  8 . The cutter  82  has indicating lines stamped thereon. 
         [0053]    The changeable cutter arbor  8  adjusts the feed amount via the thread thereon. The angle between the axis of the thread and the axis of the changeable cutter arbor  8  is 53 degree and 8 minute. The thread pitch is 1 mm. The dial for indicating linear feed amount  84  is equally divided to 20 parts, and the indicating precision is 0.04 mm. 
         [0054]    Changing the feed amount in a rotary manner is adopted on the cutter bar  1 . The incomplete turbine  31  rotates for one tooth, the feed amount changes for 0.1 mm. The dial  7  for indicating feed amount is equally divided to 50 parts, each part indicates that the feed amount changes 0.002 mm. The principle and structure of the feed amount change in a rotary manner is similar to the example 2. 
       EXAMPLE 4 
       [0055]    Example 4 is applied to a drilling and boring machine. As shown in  FIG. 11 , the structure of the cutter bar  1  is different from the example 3. The taper shank of the cutter bar  1  is engaged with the taper hole at the main axis of the drilling and boring machine (morse taper). The principle and structure of the feed amount change in a rotary manner is similar to the example 3. 
       EXAMPLE 5 
       [0056]    Referring to  FIG. 12  through  FIG. 14 , this example is applied to a machining center machine. The perspective view is shown in  FIG. 12 . The taper shank of the cutter bar is engaged with the taper hole of the axis of the machining center machine (ISO 7:24 50). 
         [0057]    An eccentric hole  11  is provided in the cutter bar  1 , wherein the axis of the eccentric hole is apart from the axis of the cutter bar. A pressure adjusting screw hole  15  for mounting pressure adjusting screw  14  and a fastening screw hole  17  for mounting fastening screw  16  are respectively provided on the cutter bar  1 . An incomplete turbine  31 , a taper hole  22  for mounting changeable cutter arbor  8 , an optical hole  25  for receiving pressure adjusting screw  14 , and a fastening screw hole for mounting fastening screw  23  are provided on the rotating taper  2  that is engaged with the eccentric taper hole  11 . A screw head hole  85  for receiving the head of the pressure adjusting crew  14  is provided at the end of the changeable cutter arbor  8 . 
         [0058]    The two sides of the worn of the turbine and worn mechanism is mounted in the worn hole  12  of the cutter bar  1  via a bearing  51 , a bearing fastener  52  and a bearing fastener with cover  53 . The worn  4  is engaged with the incomplete turbine  31 . 
         [0059]    A dial for indicating feed amount  7  is fixed on one side of the worn  4  and can rotate with the worn  4 . 
         [0060]    A first fastener  91  and a second fastener  92  of a fastening unit  9  are fastened in the fastening hole  13  of the cutter bar via a gasket  93  and a fastening bolt  94 . A fastening arch  95  matched with the outer taper arch of the rotating taper  2  is provided on the first fastener  91  and the second fastener  92  respectively. When the fastening bolt  94  is fastened, the first fastener  91  and the second fastener  92  are close to each other, so that the fastening arches  95  on the first fastener  91  and the second fastener  92  contacts and rotates the outer surface of the rotating taper  2 , so as to fasten the rotating taper. When the fastening bolt  94  is loosened, the first fastener  91  and the second fastener  92  are apart from each other, so that the fastening arches  95  on the first fastener  91  and the second fastener  92  is separated from the outer surface of the rotating taper  2 . The rotating taper  2  is driven to rotate by the worn  4  and the incomplete turbine  31 . 
         [0061]    The changeable cutter arbor  8  is mounted in the taper hole  22  of the rotating taper  2  via a screw  83 , and the cutter  82  is mounted on the changeable cutter arbor  8  via a fastening bolt  81 . 
         [0062]    A disk spring unit comprises a disk spring  18 , a pressure adjusting screw  14 , and a fastening screw  16  that is mounted on the bottom of the taper hole  22  of the rotating taper  2 . The head of the pressure adjusting screw  14  is inserted into the head hole  85  of the changeable cutter arbor  8 . The threaded segment passes through the disk spring  18  and the optical hole  25  at the bottom of the rotating taper  2  and is being inserted into the pressure adjusting screw hole  15  of the cutter bar  1 . Press the disk spring  18  tightly, so as to keep the rotating taper  2  rotating inside the cutter bar  1  without shifting the axis of the rotating taper. Fasten the fastening screw  16  in the fastening screw  17  of the cutter bar  1 , and press the pressure adjusting screw  14  so as to prevent the pressure adjusting screw  14  from loose. 
         [0063]    A flat key slot  26  is provided on the rotating taper  2 , and a flat key  27  is put in the flat key slot  26 . In order to prevent the relative movement between the rotating taper  2  and the changeable cutter arbor  8 , screw the fastening screw  23  into the fastening screw hole  24  and press the flat key  27  tightly. 
         [0064]    The changeable cutter arbor  8  is mounted in the taper hole  22  of the rotating taper  2  via a screw  83 , and the cutter  82  is mounted on the changeable cutter arbor  8  via a fastening bolt  81 . 
         [0065]    While fine adjusting, rotate the worn  4 , so that the turbine  3  drives the rotating taper  2  to rotate due to the engagement between the worn  4  and turbine  3 , and further drives the changeable cutter arbor  8  to rotate, so as to fine adjust the cutter tip of the cutter  82 . 
         [0066]    In this example, when the worn  4  rotates one circle, the feed amount changes 0.25 mm. The dial  7  for indicating the feed amount on the worn  4  has 50 indicating lines marked thereon, and each indicating line indicates that the feed amount changes 0.005 mm. Due to the small range of the fine adjustment (about 2 mm), large position shift can be achieved by adjusting the position of the cutter  82  and a plurality of changeable cutter arbor  8  of different sizes. 
       EXAMPLE 6 
       [0067]    Referring to  FIG. 15 , this example is applied to a milling machine. The perspective view is shown in  FIG. 16 . The taper shank of the cutter bar is engaged with the taper hole of the axis of the milling machine (7:24). The internal structures and the relationship of each element are same to the example 5. 
       EXAMPLE 7 
       [0068]    Referring to  FIG. 16 , this example is applied to a drilling and boring machine. The perspective view is shown in  FIG. 16 . The taper shank of the cutter bar  1  is engaged with the taper hole at the main axis of the drilling and boring machine (morse taper). The internal structures and the relationship of each element are same to the example 5. 
         [0069]    One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. 
         [0070]    It will thus be seen that the objects of the present invention have been fully and effectively accomplished. It embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.