Patent Publication Number: US-9896932-B2

Title: Cutting tool holding device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of International application No. PCT/CN2014/080449, filed Jun. 20, 2014 which claims the benefits of priority of CN application No. 201320360193.2 filed on Jun. 21, 2013, the content of which are incorporated herein by reference. 
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a cutting tool holding device. More particularly, the present disclosure relates to a cutting tool holding device mounted on a road milling machine, a machine for rotating, digging or drilling or a grinding tool. 
     Description of Related Art 
     A cutting tool holding device is configured to receive a cutting tool and is mounted on a machinery, such as a road milling machine, for applying a surface roughness treatment to a road, such as scraping, crushing or drilling, or for excavating mines. 
     Conventionally, a cutting tool holding device includes a base and a cutting tool holder. The base is fixed on a peripheral surface of a working member (such as a roller) of a machinery, and the cutting tool holder for receiving the cutting tool is fixed on the base by some fastening members. The cutting tool received in the cutting tool holder is mounted along a tangent of the base, which is favorable for applying a drilling force or a scraping force on the processed material (such as concrete or asphalt on a road). Therefore, when the road milling machine is working, a drilling operation is first applied to the processed material by the cutting tool. As the roller rotates, a scraping operation is then applied to the processed material by the cutting tool so as to destroy the processed material. 
     However, the processed material usually has a solid structure, and a reaction force generated from the processed material exerts on the cutting tool. As a result, a lifetime of the cutting tool is rather limited. Furthermore, when the cutting tool holder and the base are not firmly assembled, the cutting tool holder and the base collide with each other due to the aforementioned reaction force, and the cutting tool holder and the base are damaged thereby. As a result, a lifetime of the cutting tool holder and the base are shortened. The cost for replacing and maintaining the cutting tool holder and the base are increased significantly. 
     Therefore, how to reinforce the assembling stability between the base and the cutting tool holder so as to enhance the load value for the reaction force, prolong the lifetime of the cutting tool holder and the base, and reduce the maintaining cost is the goal of the related industries. 
     SUMMARY 
     According to one object of the present disclosure, a cutting tool holding device is provided. The cutting tool holding device includes a base, a cutting tool holder, a fitting positioning element and a pulling element. The base includes a fitting positioning hole, and the cutting tool holder includes an engaging portion. The fitting positioning element has a cross-sectional area changing gradually along an extending direction thereof. The fitting positioning element is driven by the pulling element to move in the fitting positioning hole, so that a pressing degree between the fitting positioning element and the engaging portion can be changed. Therefore, the assembling stability between the base and the cutting tool holder can be reinforced, which can enhance the load value for the reaction force of the base and the cutting tool holder, and can further to prolong the lifetime of the cutting tool holder and the base and reduce the cost of replacement and maintenance. 
     According to another object of the present disclosure, a cutting tool holding device is provided. The cutting tool holding device includes a base, a cutting tool holder, a tube positioning element and a dragging element. The base includes a tube positioning hole, and the cutting tool holder includes a fitting tube. The tube positioning element has a cross-sectional area changing gradually along an extending direction thereof. The tube positioning element is driven by the dragging element to move in the tube positioning hole, so that a pressing degree between the tube positioning element and the fitting tube can be changed. Therefore, the assembling stability between the base and the cutting tool holder can be reinforced, which can enhance the load value for the reaction force of the base and the cutting tool holder, and can further to prolong the lifetime of the cutting tool holder and the base and reduce the cost of replacement and maintenance. 
     According to one embodiment of the present disclosure, a cutting tool holding device is provided. The cutting tool holding device is for holding a cutting tool. The cutting tool holding device includes a base, a cutting tool holder, a fitting positioning element and a pulling element. 
     The base includes a first abutting portion, a second abutting portion and a fitting positioning hole, wherein the first abutting portion has an accommodating groove formed thereon, the second abutting portion is connected with the first abutting portion and defines an angle with the first abutting portion. The angle is greater than or equal to 60 degrees and is less than or equal to 120 degrees. A receiving hole is formed on the second abutting portion, and a central axis of the receiving hole is parallel to an extending direction of the accommodating groove. The fitting positioning hole is through the base and communicated with the accommodating groove, and a central axis of the fitting positioning hole is perpendicular to the extending direction of the accommodating groove. 
     The cutting tool holder is assembled between the first abutting portion and the second abutting portion of the base. The cutting tool holder includes a holder and a cutting tool receiving component. The holder includes a fitting hole and an engaging portion. The fitting hole is correspondent to the receiving hole. The engaging portion is detachably engaged in the accommodating groove. A concave portion is formed on the engaging portion, and the concave portion is communicated with the fitting positioning hole while the engaging portion is engaged in the accommodating groove. The cutting tool receiving component includes a fitting tube and a holding hole. The fitting tube is fitted into the fitting hole of the holder and the receiving hole of the second abutting portion, and the holding hole is coaxial with the fitting tube and is for holding the cutting tool. 
     The fitting positioning element is movably disposed in the fitting positioning hole. The fitting positioning element is configured to press against the concave portion of the engaging portion. A first screw hole is formed at an end of the fitting positioning element, and the fitting positioning element has a cross-sectional area changing gradually along an extending direction thereof. 
     The pulling element is restrictedly disposed in the fitting positioning hole. The pulling element includes a first screw portion, the first screw portion is engaged with the first screw hole, whereby the fitting positioning element is driven by the pulling element to move in the fitting positioning hole for changing a pressing degree between the fitting positioning element and the concave portion of the engaging portion. 
     According to the aforementioned cutting tool holding device, the base can further include a fixing screw hole communicated with the receiving hole. The cutting tool holding device can further include a screw element screwed in the fixing screw hole, and the screw element is configured to abut and fix the fitting tube of the cutting tool receiving component. 
     According to the aforementioned cutting tool holding device, the fitting positioning hole can include a first narrow portion, and the fitting positioning element is disposed at a side of the first narrow portion. The pulling element can further include a first position-limited portion connected with the first screw portion, a cross-sectional area of the first position-limited portion is greater than a cross-sectional area of the first narrow portion, the position-limited portion is disposed at the other side of the first narrow portion, and the first screw portion inserts through the first narrow portion and is engaged with the first screw hole of the fitting positioning element. 
     According to the aforementioned cutting tool holding device, the angle defined by the first abutting portion and the second abutting portion can be 90 degrees. 
     According to the aforementioned cutting tool holding device, the fitting positioning element can further include a first inclined plane formed on an outer surface thereof, and the first inclined plane is configured to press against the concave portion of the engaging portion. The concave portion of the engaging portion can include a second inclined plane, and the first inclined plane of the fitting positioning element is configured to press against the second inclined plane. 
     According to another embodiment of the present disclosure, a cutting tool holding device is provided. The cutting tool holding device is for holding a cutting tool. The cutting tool holding device includes a base, a cutting tool holder, a fitting positioning element and a pulling element. 
     The base includes a first abutting portion, a second abutting portion and a fitting positioning hole. The first abutting portion has an accommodating groove formed thereon. The second abutting portion is connected with the first abutting portion and defines an angle with the first abutting portion. The angle is greater than or equal to 60 degrees and is less than or equal to 120 degrees. A receiving hole is formed on the second abutting portion, and a central axis of the receiving hole is parallel to an extending direction of the accommodating groove. A fitting positioning hole is through the base and communicated with the accommodating groove, and a central axis of the fitting positioning hole is perpendicular to the extending direction of the accommodating groove. 
     The cutting tool holder is assembled between the first abutting portion and the second abutting portion of the base. The cutting tool holder includes an engaging portion, a fitting tube and a holding hole. The engaging portion is detachably engaged in the accommodating groove. A concave portion is formed on the engaging portion, and the concave portion is communicated with the fitting positioning hole while the engaging portion is engaged in the accommodating groove. The fitting tube is fitted into the receiving hole of the second abutting portion. The holding hole is coaxial with the fitting tube and is for holding the cutting tool. 
     The fitting positioning element is movably disposed in the fitting positioning hole. The fitting positioning element is configured to press against the concave portion of the engaging portion. A first screw hole is formed at an end of the fitting positioning element. The fitting positioning element has a cross-sectional area changing gradually along an extending direction thereof. 
     The pulling element is restrictedly disposed in the fitting positioning hole. The pulling element includes a first screw portion, the first screw portion is engaged with the first screw hole, whereby the fitting positioning element is driven by the pulling element to move in the fitting positioning hole for changing a pressing degree between the fitting positioning element and the concave portion of the engaging portion. 
     According to the aforementioned cutting tool holding device, the base can further include a fixing screw hole communicated with the receiving hole. The cutting tool holding device can further include a screw element screwed in the fixing screw hole. The screw element is configured to abut and fix the fitting tube of the cutting tool receiving component. 
     According to the aforementioned cutting tool holding device, the base can further include a tube positioning hole through the base and communicated with the receiving hole, and a central axis of the tube positioning hole is perpendicular to a central axis of the receiving hole. A depressed portion can be formed on the fitting tube of the cutting tool holder. The depressed portion is communicated with the tube positioning hole while the fitting tube is fitted into the receiving hole. The cutting tool holding device can further include a tube positioning element movably disposed in the tube positioning hole. The tube positioning element is configured to press against the depressed portion of the fitting tube. A second screw hole is formed at an end of the tube positioning element. The tube positioning element has a cross-sectional area changing gradually along an extending direction thereof. The cutting tool holding device can further include a dragging element restrictedly disposed in the tube positioning hole. The dragging element includes a second screw portion, the second screw portion is engaged with the second screw hole, whereby the tube positioning element is driven by the dragging element to move in the tube positioning hole for changing a pressing degree between the tube positioning element and the depressed portion of the fitting tube. 
     According to the aforementioned cutting tool holding device, the fitting positioning element can further include a first inclined plane formed on an outer surface thereof, and the first inclined plane is configured to press against the concave portion of the engaging portion. The tube positioning element can further include a third inclined plane formed on an outer surface thereof, and the third inclined plane is configured to press against the depressed portion of the fitting tube. The concave portion of the engaging portion can include a second inclined plane, and the first inclined plane of the fitting positioning element is configured to press against the second inclined plane. The depressed portion of the fitting tube can include a fourth inclined plane, and the third inclined plane of the tube positioning element is configured to press against the fourth inclined plane. 
     According to the aforementioned cutting tool holding device, the angle defined by the first abutting portion and the second abutting portion can be 90 degrees. 
     According to yet another embodiment of the present disclosure, a cutting tool holding device is provided. The cutting tool holding device is for holding a cutting tool. The cutting tool holding device includes a base, a cutting tool holder, a tube positioning element and a dragging element. 
     The base includes a receiving hole and a tube positioning hole. The tube positioning hole is through the base and communicated with the receiving hole, and a central axis of the tube positioning hole is perpendicular to a central axis of the receiving hole. 
     The cutting tool holder is assembled with the base. The cutting tool holder includes a fitting tube and a holding hole. The fitting tube is fitted into the receiving hole. A depressed portion is formed on the fitting tube, and the depressed portion is communicated with the tube positioning hole while the fitting tube is fitted into the receiving hole. The holding hole is coaxial with the fitting tube and is for holding the cutting tool. 
     The tube positioning element is movably disposed in the tube positioning hole. The tube positioning element is configured to press against the depressed portion of the fitting tube. A second screw hole is formed at an end of the tube positioning element. The tube positioning element has a cross-sectional area changing gradually along an extending direction thereof. 
     The dragging element is restrictedly disposed in the tube positioning hole. The dragging element includes a second screw portion, the second screw portion is engaged with the second screw hole, whereby the tube positioning element is driven by the dragging element to move in the tube positioning hole for changing a pressing degree between the tube positioning element and the depressed portion of the fitting tube. 
     According to the aforementioned cutting tool holding device, the tube positioning element can further include a third inclined plane formed on an outer surface thereof, and the third inclined plane is configured to press against the depressed portion of the fitting tube. The depressed portion of the fitting tube can include a fourth inclined plane, and the third inclined plane of the tube positioning element is configured to press against the fourth inclined plane. 
     According to the aforementioned cutting tool holding device, a number of the tube positioning holes of the base can be two. The tube positioning holes are separately through the base. Each of the tube positioning holes is communicated with the receiving hole, and a central axis of each of the tube positioning holes is perpendicular to the central axis of the receiving hole. A number of the depressed portions formed on the fitting tube can be two, and the two depressed portions are communicated with the two tube positioning holes respectively while the fitting tube is fitted into the receiving hole. A number of the tube positioning elements can be two. The two tube positioning elements are movably disposed in the two tube positioning holes respectively, and the two tube positioning elements are configured to press against the two depressed portions of the fitting tube respectively. A number of the dragging elements can be two, and the two dragging elements are restrictedly disposed in the two tube positioning holes respectively. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: 
         FIG. 1  is a three-dimensional view of a cutting tool holding device according to the 1st embodiment of the present disclosure; 
         FIG. 2  is an exploded view of the cutting tool holding device shown in  FIG. 1 ; 
         FIG. 3  is another exploded view of a holder and a fitting positioning element in  FIG. 2 ; 
         FIG. 4  is a cross-sectional view taken along line  4 - 4  of the cutting tool holding device shown in  FIG. 1 ; 
         FIG. 5  is an operating schematic view of the cutting tool holding device shown in  FIG. 1 ; 
         FIG. 6  is an exploded view of a holder and a fitting positioning element of a cutting tool holding device according to the 2nd embodiment of the present disclosure; 
         FIG. 7  is an exploded view of a cutting tool holding device according to the 3rd embodiment of the present disclosure; 
         FIG. 8  is an assembling view of a holder and a fitting positioning element shown in  FIG. 7 ; 
         FIG. 9  is a three-dimensional view of a cutting tool holder of a cutting tool holding device according to the 4th embodiment of the present disclosure; 
         FIG. 10  is a three-dimensional view of a cutting tool holding device according to the 5th embodiment of the present disclosure; 
         FIG. 11  is an exploded view of the cutting tool holding device shown in  FIG. 10 ; 
         FIG. 12  is a side view of a cutting tool holder shown in  FIG. 11 ; 
         FIG. 13  is a rear view of the cutting tool holder shown in  FIG. 12 ; 
         FIG. 14  is a three-dimensional view of a cutting tool holding device according to the 6th embodiment of the present disclosure; 
         FIG. 15  is an exploded view of the cutting tool holding device shown in  FIG. 14 ; 
         FIG. 16  is a three-dimensional view of a cutting tool holding device according to the 7th embodiment of the present disclosure; and 
         FIG. 17  is an exploded view of the cutting tool holding device shown in  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION 
     Please refer to  FIG. 1  to  FIG. 3 .  FIG. 1  is a three-dimensional view of a cutting tool holding device  100  according to the 1st embodiment of the present disclosure.  FIG. 2  is an exploded view of the cutting tool holding device  100  shown in  FIG. 1 .  FIG. 3  is another exploded view of a holder  130  and a fitting positioning element  150  shown in  FIG. 2 . The cutting tool holding device  100  is for holding a cutting tool B (shown in  FIG. 5 ). The cutting tool holding device  100  includes a base  110 , a cutting tool holder  120 , a screw element  115 , a fitting positioning element  150  and a pulling element  160 . The cutting tool holder  120  is assembled on the base  110 . The screw element  115 , the fitting positioning element  150  and the pulling element  160  are inserted in the base  110 . 
     The base  110  includes a first abutting portion  111 , a second abutting portion  112 , a fitting positioning hole  113  and a fixing screw hole  114 . The first abutting portion  111  is connected with the second abutting portion  112 . The first abutting portion  111  and the second abutting portion  112  define an angle A 1 . The angle A 1  is greater than or equal to 60 degrees and is less than or equal to 120 degrees. Therefore, the assembling stability between the cutting tool holder  120  and the base  110  can be enhanced. Preferably, the angle A 1  is equal to 90 degrees. The first abutting portion  111  has an accommodating groove  111   a  formed thereon. The second abutting portion  112  has a receiving hole  112   a  formed thereon. A central axis (not shown) of the receiving hole  112   a  is parallel to an extending direction of the accommodating groove  111   a . The fitting positioning hole  113  is through the base  110  and communicated with the accommodating groove  111   a . A central axis (not shown) of the fitting positioning hole  113  is perpendicular to the extending direction of the accommodating groove  111   a . The fixing screw hole  114  is communicated with the receiving hole  112   a.    
     The cutting tool holder  120  is assembled between the first abutting portion  111  and the second abutting portion  112 . The cutting tool holder  120  includes a holder  130  and a cutting tool receiving component  140 . 
     The holder  130  includes a fitting hole  131  and an engaging portion  132 . A concave portion  133  is formed on the engaging portion  132 . The fitting hole  131  is correspondent to the receiving hole  112   a . The engaging portion  132  is detachably engaged in the accommodating groove  111   a . The concave portion  133  is communicated with the fitting positioning hole  113  while the engaging portion  132  is engaged in the accommodating groove  111   a.    
     The cutting tool receiving component  140  includes a fitting tube  141  and a holding hole  142 . The fitting tube  141  is coaxial with the holding hole  142 . The fitting tube  141  is fitted into the fitting hole  131  of the holder  130  and the receiving hole  112   a  of the second abutting portion  112 . The holding hole  142  is for holding the cutting tool B (shown in  FIG. 5 ). 
     The screw element  115  has a screw thread formed on an outer surface thereof. Therefore, the screw element  115  can be screwed in the fixing screw hole  114  so as to abut and fix the fitting tube  141  of the cutting tool receiving component  140 . According to one example of the present disclosure, the fitting tube  141  of the cutting tool receiving component  140  can have a positioning concave (refer to the positioning concave  441   a  shown in  FIG. 9 ). The positioning concave is correspondent to the screw element  115 , so that the abutting and fixing effect between the screw element  115  and the fitting tube  141  can be enhanced, and the assembling ability between the base  110  and the cutting tool receiving component  140  can be enhanced. 
     The fitting positioning element  150  is movably disposed in the fitting positioning hole  113 . The fitting positioning element  150  is configured to press against the concave portion  133  of the engaging portion  132 . A first screw hole  151  is formed at an end of the fitting positioning element  150 . In the embodiment, the first screw hole  151  goes through the fitting positioning element  150  and is a through hole. In other embodiment, the first screw hole  151  can be configured as not going through the fitting positioning element  150 . A first inclined plane  152  is formed on an outer surface of the fitting positioning element  150 . Thus, the fitting positioning element  150  has a cross-sectional area changing gradually along an extending direction thereof, and the fitting positioning element  150  presses against the concave portion  133  of the engaging portion  132  via the first inclined plane  152 . 
     The pulling element  160  is restrictedly disposed in the fitting positioning hole  113 . The pulling element  160  includes a first screw portion  161  and a first position-limited portion  162 . The first position-limited portion  162  is connected with the first screw portion  161 , and a cross-sectional area of the first position-limited portion  162  is greater than a cross-sectional area of the first screw portion  161 . 
     Please refer to  FIG. 4 , which is a cross-sectional view taken along line  4 - 4  of the cutting tool holding device  100  shown in  FIG. 1 . The fitting positioning hole  113  of the base  110  includes a first narrow portion  113   a . The fitting positioning element  150  is disposed at a side of the first narrow portion  113   a . The first position-limited portion  162  of the pulling element  160  is disposed at the other side of the first narrow portion  113   a , and the first screw portion  161  of the pulling element  160  inserts through the first narrow portion  113   a  and is engaged with the first screw hole  151  of the fitting positioning element  150 . The cross-sectional area of the first position-limited portion  162  is greater than a cross-sectional area of the first narrow portion  113   a . Therefore, the displacement of first position-limited portion  162  from one side to the other side of the first narrow portion  113   a  can be prevented, so that the position of the pulling element  160  can be limited. Furthermore, with the engagement between the first screw portion  161  and the first screw hole  151 , the fitting positioning element  150  is driven by the pulling element  160  to move in the fitting positioning hole  113  for changing a pressing degree between the fitting positioning element  150  and the concave portion  133  of the engaging portion  132 . 
     From the above, with the pressing degree between the fitting positioning element  150  and the concave portion  133  of the engaging portion  132 , a looseness between the base  110  and the cutting tool holder  120  can be prevented, so that the load value for the reaction force of the base  110  and the cutting tool holder  120  can be enhanced. Accordingly, the lifetime of the base  110  and the cutting tool holder  120  can be prolonged, and the maintaining cost can be reduced. Moreover, with the engagement between the first screw portion  161  of the pulling element  160  and the first screw hole  151  of the fitting positioning element  150 , a user can rotate the pulling element  160  so as to precisely adjust the pressing degree between the fitting positioning element  150 , the base  110  and the cutting tool holder  120 . Therefore, the cutting tool holding device  100  according to the present disclosure further has the advantages of easy operation and high adjustment precision. 
     Please refer to  FIG. 5 , which is an operating schematic view of the cutting tool holding device  100  shown in  FIG. 1 . The cutting tool holding device  100  is mounted on a machinery  900  for applying a surface roughness treatment to a road. The cutting tool B is received in the cutting tool holding device  100 . The cutting tool B is applied to process a processed material, such as the surface of the road. By reinforcing the assembling stability between the base  110  and the cutting tool holder  120 , the lifetime of the base  110  and the cutting tool holder  120  can be prolonged, and the maintaining cost can be reduced. 
     Please refer to  FIG. 6 , which is an exploded view of a holder  230  and a fitting positioning element  250  of a cutting tool holding device according to the 2nd embodiment of the present disclosure. In the 2nd embodiment, the holder  230  includes a fitting hole  231  and an engaging portion  232 . A concave portion  233  is formed on the engaging portion  232 . The concave portion  233  includes a second inclined plane  233   a . The fitting positioning element  250  includes a first screw hole  251  and a first inclined plane  252 . When the holder  230  and a base (not shown) are assembled, the first inclined plane  252  of the fitting positioning element  250  presses against the second inclined plane  233   a  of the concave portion  233 . Therefore, the contact area between the first inclined plane  252  and the concave portion  233  can be enhanced, so that the pressing degree between the fitting positioning element  250  and the concave portion  233  can be enhanced. The rest details of the 2nd embodiment are the same as that of the 1st embodiment, and will not be repeated herein. 
     Please refer to  FIG. 7  and  FIG. 8 .  FIG. 7  is an exploded view of a cutting tool holding device  300  according to the 3rd embodiment of the present disclosure.  FIG. 8  is an assembling view of a holder  330  and a fitting positioning element  350  shown in  FIG. 7 . The cutting tool holding device  300  includes a base  310 , a cutting tool holder  320 , a screw element  315 , the fitting positioning element  350  and a pulling element  360 . The cutting tool holder  320  is assembled on the base  310 . The screw element  315 , the fitting positioning element  350  and the pulling element  360  are inserted in the base  310 . 
     The base  310  includes a first abutting portion  311 , a second abutting portion  312 , a fitting positioning hole  313  and a fixing screw hole  314 . The first abutting portion  311  is connected with the second abutting portion  312 . The first abutting portion  311  and the second abutting portion  312  define an angle A 1 . The angle A 1  is greater than or equal to 60 degrees and is less than or equal to 120 degrees. Therefore, the assembling stability between the cutting tool holder  320  and the base  310  can be enhanced. Preferably, the angle A 1  is equal to 90 degrees. The first abutting portion  311  has an accommodating groove  311   a  formed thereon. The second abutting portion  312  has a receiving hole  312   a  formed thereon. A central axis (not shown) of the receiving hole  312   a  is parallel to an extending direction of the accommodating groove  311   a . The fitting positioning hole  313  is through the base  310  and communicated with the accommodating groove  311   a . A central axis (not shown) of the fitting positioning hole  313  is perpendicular to the extending direction of the accommodating groove  311   a . The fixing screw hole  314  is communicated with the receiving hole  312   a.    
     The cutting tool holder  320  is assembled between the first abutting portion  311  and the second abutting portion  312 . The cutting tool holder  320  includes the holder  330  and a cutting tool receiving component  340 . 
     The holder  330  includes a fitting hole  331  and an engaging portion  332 . A concave portion  333  is formed on the engaging portion  332 . One side of the concave portion  333  is formed in a ridge shape which includes two symmetrical second inclined plane  333   a.    
     The cutting tool receiving component  340  includes a fitting tube  341  and a holding hole  342 . The fitting tube  341  is coaxial with the holding hole  342 . The fitting tube  341  is fitted into the fitting hole  331  of the holder  330  and the receiving hole  312   a  of the second abutting portion  312 . The holding hole  342  is for holding a cutting tool (not shown). 
     The screw element  315  has a screw thread formed on an outer surface thereof. Therefore, the screw element  315  can be screwed in the fixing screw hole  314  so as to abut and fix the fitting tube  341  of the cutting tool receiving component  340 . 
     The fitting positioning element  350  is movably disposed in the fitting positioning hole  313 . The fitting positioning element  350  is configured to press against the concave portion  333  of the engaging portion  332 . A first screw hole  351  is formed at an end of the fitting positioning element  350 . In the embodiment, the first screw hole  351  goes through the fitting positioning element  350  and is a through hole. In other embodiment, the first screw hole  351  can be configured as not going through the fitting positioning element  350 . A first inclined plane  352  is formed on an outer surface of the fitting positioning element  350 . Thus, the fitting positioning element  350  has a cross-sectional area changing gradually along an extending direction thereof, and the fitting positioning element  350  presses against the second inclined plane  333   a  of the concave portion  333  of the engaging portion  332  via the first inclined plane  352 . 
     The pulling element  360  is restrictedly disposed in the fitting positioning hole  313 . The pulling element  360  includes a first screw portion  361  and a first position-limited portion  362 . The first position-limited portion  362  is connected with the first screw portion  361 . The first screw portion  361  of the pulling element  360  is engaged with the first screw hole  351  of the fitting positioning element  350 . Therefore, the fitting positioning element  350  is driven by the pulling element  360  to move in the fitting positioning hole  313  for changing a pressing degree between the fitting positioning element  350  and the second inclined plane  333   a  of the concave portion  333 . 
     Please refer to  FIG. 9 , which is a three-dimensional view of cutting tool holder  420  of a cutting tool holding device according to the 4th embodiment of the present disclosure. In the 4th embodiment, the cutting tool holder  420  includes an engaging portion  432 , a fitting tube  441  and a holding hole  442 . A concave portion  433  is formed on the engaging portion  432 . The positioning concave  441   a  is formed on the fitting tube  441 . The positioning concave  441   a  is correspondent to a screw element (not shown), so that the abutting and fixing effect between the screw element and the fitting tube  441  can be enhanced. In the 4th embodiment, the cutting tool holder  420  is integrally formed and cannot be disassembled into a holder and a cutting tool receiving component. Accordingly, the structure of the cutting tool holder  420  is simpler. The rest details of the 4th embodiment are the same as that of the 1st embodiment, and will not be repeated herein. 
     Please refer to  FIG. 10  and  FIG. 11 .  FIG. 10  is a three-dimensional view of a cutting tool holding device  500  according to the 5th embodiment of the present disclosure.  FIG. 11  is an exploded view of the cutting tool holding device  500  shown in  FIG. 10 . The cutting tool holding device  500  includes a base  510 , a cutting tool holder  520 , a fitting positioning element  550 , a pulling element  560 , a tube positioning element  570  and a dragging element  580 . The cutting tool holder  520  is assembled on the base  510 . The fitting positioning element  550 , the pulling element  560 , the tube positioning element  570  and the dragging element  580  are inserted in the base  510 . 
     The base  510  includes a first abutting portion  511 , a second abutting portion  512 , a fitting positioning hole  513  and a tube positioning hole  516 . The first abutting portion  511  is connected with the second abutting portion  512 . The first abutting portion  511  and the second abutting portion  512  define an angle A 1 . The angle A 1  is greater than or equal to 60 degrees and is less than or equal to 120 degrees. Therefore, the assembling stability between the cutting tool holder  520  and the base  510  can be enhanced. Preferably, the angle A 1  is equal to 90 degrees. The first abutting portion  511  has an accommodating groove  511   a  formed thereon. The second abutting portion  512  has a receiving hole  512   a  formed thereon. A central axis (not shown) of the receiving hole  512   a  is parallel to an extending direction of the accommodating groove  511   a . The fitting positioning hole  513  is through the base  510  and communicated with the accommodating groove  511   a . A central axis (not shown) of the fitting positioning hole  513  is perpendicular to the extending direction of the accommodating groove  511   a . The tube positioning hole  516  is through the base  510  and communicated with the receiving hole  512   a . A central axis of the tube positioning hole  516  is perpendicular to a central axis of the receiving hole  512   a.    
     The cutting tool holder  520  is assembled between the first abutting portion  511  and the second abutting portion  512 . The cutting tool holder  520  includes an engaging portion  532 , a fitting tube  541  and a holding hole  542 . The holding hole  542  is coaxial with the fitting tube  541  and is for holding a cutting tool (not shown). A concave portion  533  is formed on the engaging portion  532 , and the concave portion  533  includes a second inclined plane  533   a . A depressed portion  543  is formed on the fitting tube  541 , and the depressed portion  543  includes a fourth inclined plane  543   a . The engaging portion  532  is detachably engaged in the accommodating groove  511   a . The concave portion  533  is communicated with the fitting positioning hole  513  and the depressed portion  543  is communicated with the tube positioning hole  516  while the engaging portion  532  is engaged in the accommodating groove  511   a  and the fitting tube  541  is fitted into the receiving hole  512   a.    
     The fitting positioning element  550  is movably disposed in the fitting positioning hole  513 . A first screw hole  551  is formed at an end of the fitting positioning element  550 . In the embodiment, the first screw hole  551  goes through the fitting positioning element  550  and is a through hole. In other embodiment, the first screw hole  551  can be configured as not going through the fitting positioning element  550 . A first inclined plane  552  is formed on an outer surface of the fitting positioning element  550 . Thus, the fitting positioning element  550  has a cross-sectional area changing gradually along an extending direction thereof, and the fitting positioning element  550  presses against the second inclined plane  533   a  of the concave portion  533  of the engaging portion  532  via the first inclined plane  552 . Therefore, the contact area between the fitting positioning element  550  and the concave portion  533  can be enhanced, so that the pressing degree between the fitting positioning element  550  and the concave portion  533  can be enhanced. 
     The tube positioning element  570  is movably disposed in the tube positioning hole  516 . A second screw hole  571  is formed at an end of the tube positioning element  570 . In the embodiment, the second screw hole  571  goes through the tube positioning element  570  and is a through hole. In other embodiment, the second screw hole  571  can be can be configured as not going through the tube positioning element  570 . A third inclined plane  572  is formed on an outer surface of the tube positioning element  570 . Thus, the tube positioning element  570  has a cross-sectional area changing gradually along an extending direction thereof, and the tube positioning element  570  presses against the fourth inclined plane  543   a  of the depressed portion  543  of the fitting tube  541  via the third inclined plane  572 . Therefore, the contact area between the tube positioning element  570  and the depressed portion  543  can be enhanced, so that the pressing degree between the tube positioning element  570  and the depressed portion  543  can be enhanced. 
     The pulling element  560  is restrictedly disposed in the fitting positioning hole  513 . The pulling element  560  includes a first screw portion  561  and a first position-limited portion  562 . The first position-limited portion  562  is connected with the first screw portion  561 . The first screw portion  561  of the pulling element  560  is engaged with the first screw hole  551  of the fitting positioning element  550 . Therefore, the fitting positioning element  550  is driven by the pulling element  560  to move in the fitting positioning hole  513  for changing a pressing degree between the fitting positioning element  550  and the second inclined plane  533   a  of the concave portion  533 . 
     The dragging element  580  is restrictedly disposed in the tube positioning hole  516 . The dragging element  580  includes a second screw portion  581  and a second position-limited portion  582 . The second position-limited portion  582  is connected with the second screw portion  581 . The second screw portion  581  of the dragging element  580  is engaged with the second screw hole  571  of the tube positioning element  570 . Therefore, the tube positioning element  570  is driven by the dragging element  580  to move in the tube positioning hole  516  for changing a pressing degree between the tube positioning element  570  and the fourth inclined plane  543   a  of the depressed portion  543 . 
     Please refer to  FIG. 12  and  FIG. 13 .  FIG. 12  is a side view of the cutting tool holder  520  shown in  FIG. 11 .  FIG. 13  is a rear view of the cutting tool holder  520  shown in  FIG. 12 . As shown in  FIG. 12  and  FIG. 13 , the second inclined plane  533   a  and the fourth inclined plane  543   a  are oblique planes in the embodiment. Therefore, the assembling stability between the base  510  and the cutting tool holder  520  can be further enhanced. Specifically, for a virtual orthogonal coordinate system, the second inclined plane  533   a  and the fourth inclined plane  543   a  are not parallel to nor perpendicular to any of the X-Y plane, the X-Z plane and the Y-Z plane. The Z axis of the virtual orthogonal coordinate system is defined by the direction that the cutting tool fitted into the cutting tool holder  520 . The X axis is defined by the central axis of the fitting positioning hole  513 . The Y axis is defined by the X axis and the Z axis. According to one embodiment of the present disclosure, an angle A 2  between the second inclined plane  533   a  and the X axis is ranging from 4 degrees to 10 degrees. Preferably, the angle A 2  between the second inclined plane  533   a  and the X axis is 5 degrees. An angle A 3  between the fourth inclined plane  543   a  and the X axis is ranging from 4 degrees to 10 degrees. Preferably, the angle A 3  between the fourth inclined plane  543   a  and the X axis is 5 degrees. 
     Please refer to  FIG. 14  and  FIG. 15 .  FIG. 14  is a three-dimensional view of a cutting tool holding device  600  according to the 6th embodiment of the present disclosure.  FIG. 15  is an exploded view of the cutting tool holding device  600  shown in  FIG. 14 . The cutting tool holding device  600  is for holding a cutting tool (not shown). The cutting tool holding device  600  includes a base  610 , a cutting tool holder  620 , a tube positioning element  670  and a dragging element  680 . 
     The base  610  includes a receiving hole  612   a  and a tube positioning hole  616 . The tube positioning hole  616  is through the base  610  and communicated with the receiving hole  612   a , and a central axis of the tube positioning hole  616  is perpendicular to a central axis of the receiving hole  612   a.    
     The cutting tool holder  620  is assembled with the base  610 . The cutting tool holder  620  includes a fitting tube  641  and a holding hole  642 . The holding hole  642  is coaxial with the fitting tube  641  and is for holding a cutting tool. A depressed portion  643  is formed on the fitting tube  641 , and the depressed portion  643  includes a fourth inclined plane  643   a . The depressed portion  643  is communicated with the tube positioning hole  616  while the fitting tube  641  is fitted into the receiving hole  612   a.    
     The tube positioning element  670  is movably disposed in the tube positioning hole  616 . A second screw hole  671  is formed at an end of the tube positioning element  670 . In the embodiment, the second screw hole  671  goes through the tube positioning element  670  and is a through hole. A third inclined plane  672  is formed on an outer surface of the tube positioning element  670 . Thus, the tube positioning element  670  has a cross-sectional area changing gradually along an extending direction thereof, and the tube positioning element  670  presses against the fourth inclined plane  643   a  of the depressed portion  643  of the fitting tube  641  via the third inclined plane  672 . Therefore, the contact area between the tube positioning element  670  and the depressed portion  643  can be enhanced, so that the pressing degree between the tube positioning element  670  and the depressed portion  643  can be enhanced. 
     The dragging element  680  is restrictedly disposed in the tube positioning hole  616 . The dragging element  680  includes a second screw portion  681  and a second position-limited portion  682 . The second position-limited portion  682  is connected with the second screw portion  681 . The second screw portion  681  of the dragging element  680  is engaged with the second screw hole  671  of the tube positioning element  670 . Therefore, the tube positioning element  670  is driven by the dragging element  680  to move in the tube positioning hole  616  for changing a pressing degree between the tube positioning element  670  and the fourth inclined plane  643   a  of the depressed portion  643 . 
     Please refer to  FIG. 16  and  FIG. 17 .  FIG. 16  is a three-dimensional view of a cutting tool holding device  700  according to the 7th embodiment of the present disclosure.  FIG. 17  is an exploded view of the cutting tool holding device  700  shown in  FIG. 16 . The cutting tool holding device  700  includes a base  710 , a cutting tool holder  720 , two tube positioning elements  770  and two dragging elements  780 . The base  710  includes two tube positioning holes  716 . The tube positioning holes  716  are separately through the base  710 . The cutting tool holder  720  includes a holding hole  742  and a fitting tube  741 . Two depressed portions  743  are formed on the fitting tube  741 . The two tube positioning elements  770  are disposed in the two tube positioning holes  716 , respectively. Each of the tube positioning elements  770  includes a second screw hole  771  and a third inclined plane  772 . The two dragging elements  780  are restrictedly disposed in the two tube positioning holes  716 , respectively. Each of the dragging element  780  includes a second screw portion  781  and a second position-limited portion  782 . The assembling stability between the base  710  and the cutting tool holder  720  can be further enhanced by increasing the number of the tube positioning elements  770 , the dragging elements  780  and the depressed portions  743 . The rest details of the 7th embodiment are the same as that of the 6th embodiment, and will not be repeated herein. 
     According to the forgoing embodiments, by driving the fitting positioning element to move in the fitting positioning hole with the pulling element, the pressing degree between the fitting positioning element and the engaging portion can be changed. Alternatively, by driving the tube positioning element to move in the tube positioning hole with the dragging element, the pressing degree between the tube positioning element and the fitting tube can be changed. Therefore, the assembling stability between the base and the cutting tool holder can be reinforced, which can enhance the load value for the reaction force of the base and the cutting tool holder, and can further to prolong the lifetime of the cutting tool holder and the base, and can reduce the cost of replacement and maintenance. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims.