Patent Publication Number: US-2005143237-A1

Title: Tool magazine feeder for automatic tool changer

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a tool magazine feeder for an automatic tool changer, and in particular to a tool magazine feeder for an automatic tool changer designed to feed a tool magazine to a spindle.  
      2. Description of the Related Art  
      As is well known in the art, a machine tool, such as a numerical control lathe, a machining center, or the like, is adapted to accomplish cutting operation with the use of different kinds of tools. For this reason, the conventional machine tool is provided with an automatic tool changer (ATC) for changing one tool with another in an automated manner.  
      The automatic tool changer comprises a tool magazine  1  containing a plurality of tools T, and a feeder  5  capable of feeding the tool magazine  1  to a spindle  3  laterally spaced from the tool magazine  1 , as shown in  FIG. 1 . In particular, the feeder  5  comprises a carriage  7  arranged to be horizontally movable on a frame  1   a  while supporting the tool magazine  1 , and an actuator  8  for horizontally moving the carriage  7 .  
      The carriage  7  moves along a pair of guide roads  7   a  mounted on the frame  1   a , in which the carriage  7  reciprocates between a “remote position” C spaced from the spindle  3  and a “proximate position” D while horizontally moving along the guide rods  7   a , thereby aligning the tool magazine  1  supported under the carriage  7  with the spindle  3  or spacing the tool magazine  1  from the spindle  3 .  
      The actuator  8  consists of a pneumatic cylinder and moves the carriage  7  between the “remote position” C and the “proximate position” D while being extended and retracted by compressed air coming in and out the actuator  8 .  
      Meanwhile, such a conventional tool magazine feeder  5  has a problem in that the tool magazine  1  cannot be correctly moved to a predetermined position due to the difficulty in precisely controlling the tool magazine feeder  5 . Specifically, the conventional feeder  5  suffers from variation in pressure and amount of air coming in and out the actuator  8  each time, because the actuator  8  for moving the carriage  7  is operated by air which is a kind of compressible gas. Accordingly, the carriage  7  has a problem in that it cannot move to one and same “proximate position” D each time while moving between the “remote position” C and the “proximate position” D.  
      Such a problem makes it impossible to correctly align the tool magazine  1  with the spindle  1 , thereby causing a malfunction.  
      Taking this into consideration, the carriage comprises a stopper  9  for limiting the carriage  7  at a predetermined position, so that the carriage  7  can stop at the same “proximate position” D each time. However, in such a case, there is a problem in that noise and impact are caused while the carriage runs into and interferes with the stopper  9 .  
      Moreover, there is also a problem in that the carriage  7  may be abruptly operated or stopped when the pressure of the compressed air supplied to the actuator  8  is abruptly lowered or raised, whereby impact and noise are produced. Such a problem causes deterioration of endurance of the feeder  5 .  
      In addition, the feeder  5  comprises an actuator  8  configured in a large capacity; because a large amount of compressed air is supplied to the actuator, air pressure supplied to another pneumatic device requiring a relatively large amount of compressed air may be affected, whereby the pneumatic device may be occasionally caused to malfunction.  
      Furthermore, there is a disadvantage in that as the guide roads  7   a  for guiding the carriage  7  are configured in a circular form and the-carriage  7  moving along the guide roads  7   a  are separately provided with bush-type bearings  7   b , the feeder  5  is very complicate in construction and difficult to repair and assemble, and high precision is required for the feeder  5 . In particular, there is a disadvantage in that because the guide roads  7   a  should be worked with high precision, a lot of time and costs are required to work the guide roads  7   a.    
     SUMMARY OF THE INVENTION  
      Accordingly, the present invention has been made to solve the above-mentioned problems inherent in the prior art, and it is an object of the present invention to provide a tool magazine feeder for an automatic tool changer that allows a tool magazine to be moved to a correct position, without noise and impact.  
      Another object of the present invention is to provide a tool magazine feeder for an automatic tool changer that can prevent abrupt movement and stopping of a tool magazine which would otherwise caused by unstable supply of compressed air.  
      Still another object of the present invention is to provide a tool magazine feeder for an automatic tool changer that does not adversely affect the pressure and amount of compressed air supplied to another pneumatic device by configuring a tool magazine to be movable without being supplied with compressed air.  
      In order to achieve the above-mentioned objects, there is provided a tool magazine feeder for an automatic tool changer for feeding a tool magazine to a spindle, comprising: a carriage horizontally movable, under the state of supporting the tool magazine, between a remote position where the carriage is separated from the spindle and a proximate position where the carriage is adjacent to the spindle; driving means for reciprocating the carriage from the remote position to the proximate position and vice versa; and guide means positioned between the carriage and the driving means, the guide means comprising one or more rollers and one or more rails for guiding the carriage to horizontally move between the remote position and the proximate position, wherein the driving means comprises: a forward/reverse motor with an output shaft; and an operation lever secured to the output shaft of the forward/reverse motor for pivoting movement between first and second positions, the operation lever adapted to push the carriage from the remote position to the proximate position when the lever is caused to pivot from the first position to the second position and push the carriage from the proximate position to the remote position when the lever is caused to pivot from the second position to the first position.  
      Preferably, a finger is formed at a tip end of the operation lever to directly push the carriage, and a vertical slot is formed in the carriage, wherein the finger is capable of being movably inserted into the vertical slot. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:  
       FIG. 1  is a front elevational view of a tool magazine feeder for an automatic tool changer of the prior art;  
       FIG. 2  is a front elevational view of a tool magazine feeder for an automatic tool changer according to the present invention;  
       FIG. 3  is a cross-sectional view taken along the line III-III of  FIG. 2 ;  
       FIG. 4  is a cross-sectional view showing a variant of the carriage guide part forming the inventive tool magazine feeder; and  
       FIGS. 5A  to  5 C are views showing the operation of the inventive tool magazine feeder. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Hereinafter, preferred embodiments for a cooling device for a spindle built-in type spindle motor according to the present invention will be described with reference to the accompanying drawings. Components same with the conventional ones described above will be respectively indicated by the same reference numerals used in describing the prior art.  
      As shown in  FIGS. 2 and 3 , the inventive tool magazine feeder comprises a pair of guide rails  10  horizontally mounted on a frame  1   a . The pair of guide rails  10  are provided in parallel and vertically spaced from each other.  
      In addition, the inventive tool magazine feeder has a carriage  20  horizontally moving along the guide rails  10 . The carriage  20  consists of a vertical plate  22  movably mounted on the pair of guide rails  10  and a horizontal plate  24  secured to the lower end of the vertical plate  22  as shown in  FIG. 3 . In particular, a tool magazine  1  is mounted on the horizontal plate  24 .  
      This carriage  20  horizontally moves along the guide rails  10  in the state of supporting the tool magazine  1 . In particular, the carriage  20  reciprocates between a “remote position” C spaced from the spindle  3  and a “proximate position” D while horizontally moving along the guide rails  10 , thereby aligning/spacing the tool magazine  1  supported below the tool magazine  1  with/from the spindle  3 .  
      Meanwhile, the vertical plate  22  of the carriage  20  is provided with a plurality of rollers  26  to aid smooth movement along the guide rails  10 . The guide rails  10  and the rollers  26  are guide means for guiding the horizontal movement of the carriage  20 . Although  FIGS. 2 and 3  show that the guide means for guiding the horizontal movement of the carriage  20  of the present invention consists of a pair of rollers  26  and a pair of guide rails  10  corresponding to the rollers  26 , it is also possible that the upper part of the guide means is configured by a roller  26  and a rail  10  and the lower part is configured by a “L” shaped guide channel  12  and a roller  26  as shown in  FIG. 4 . Of course, it is also possible to use a “U” shaped guide channel in place of the “L” shaped guide channel  12 .  
      Referring to  FIGS. 2 and 3  again, the inventive tool magazine feeder comprises driving means for moving the carriage  20  from the “remote position” C to the “proximate position” D or from the “proxinate position” D to the “remote position” C.  
      The driving means comprises a forward/reverse motor  30  and an operation lever  32  secured to the output shaft  30   a  of the forward/reverse motor  30 . In particular, the operation lever  32  is pivotally reciprocated between a “first position” X and a “second position” Y, wherein the operation lever  32  is arranged in such a way that it pushes the carriage  20  from the “remote position” C to the “proximate position” D while forwardly pivoting from the “first position” X to the “second position” Y and pushes the carriage  20  from the “proximate position” D to the “remote position” C while reversely pivoting from the “second position” to the “first position.” 
      Here, a finger  32   a  is projected from the tip end of the operation lever  32  to directly compress the vertical plate  22  of the carriage  20 . A vertical slot  22   a  is formed in the vertical plate  22  of the carriage  20 , in which slot the finger  32   a  of the operation lever  32  is supported to be vertically movable as well as rotatable. Meanwhile, the finger  32   a  of the operation lever  32  is provided with a rolling roller  32   b  so that the finger  32   a  and the vertical slot  22   a  smoothly come into contact with each other.  
      According to the driving means configured as described above, by pivoting the operation lever  32  with the forward/reverse motor  30  and horizontally reciprocating the carriage  20  with the operation lever  32 , it is possible to reciprocate the carriage  20  from the “remote position” C to the “proximate position” D and from the “proximate position” D to the “remote position” C.  
      Meanwhile, on the way of pivoting between the “first position” X and the “second position” Y, the operation lever  32  is forwardly/reversely pivoted to a position where the finger  32   a  formed at the tip end of the operation lever is engaged with the lower end  22   b  of the vertical slot  22   a  of the carriage  20 .  
      Referring to  FIG. 2  again, the inventive tool magazine feeder comprises motor control means for stopping the forward/reverse motor  30  when the operation lever  32  is pivoted to the “first position” X or the “second position” Y.  
      The motor control means comprises a first detection sensor  40  for detecting whether the operation lever  32  is located at the “first position” X, a second detection sensor  42  for detecting whether the operation lever  32  is located at the “second position” Y, and a controller  44  for stopping the forward/reverse motor  30  in response to the detection signals inputted from the first and second detection sensors  40 ,  42 .  
      With the motor control means, by stopping the forward/reverse motor  30  after the operation lever  32  moving to the “first position” X or the “second position” Y is detected, it is possible to allow the operation lever  32  to correctly stop at the “first position” X or the “second position” Y. In particular, by allowing the operation lever  32  to correctly stop at the “first position” X or the “second position” Y, it is possible to allow the carriage  20  moved by the operation lever  32  to be correctly fixed at the “remote position” C or the “proximate position” D.  
      Meanwhile, although it has been described that the present invention controls the position of the operation lever  32  with the aid of the first detection sensor  40 , the second detection sensor  42  and the controller  44 , it is possible to directly control the operation lever  32  by fabricating the forward/reverse motor  30  itself as a servo-motor.  
      Referring to  FIGS. 2 and 3  again, the inventive tool magazine feeder includes vibration suppression means for preventing the finger  32   a  at the tip end of the operation lever  30  from vibrating as the finger  32   a  runs into the lower end  22   b  of the vertical slot  22   a  of the carriage while the operation lever  32  rapidly pivots from the “first position” X to the “second position” Y or from the “second position” Y to the “first position” X.  
      The vibration suppression means consists of a spring  50 , one end of which is supported by the frame  1   a  and the other end of which is supported by the finger  32   a  of the operation lever  30 . The spring  50  resiliently supports downwardly the operation lever  32  pivoting to the “first position” X or the “second position” Y, wherein the spring  50  serves to urge the finger  32   a  of the operation lever  32   a  against the lower end  22   b  of the vertical lever  22   a . In particular, by urging the finger  32   a  of the operation lever  32  against the lower end  22   b  of the vertical slot  22   a , the operation lever  32  is prevented from bounding and vibrating by the contact between the finger  32   a  and the lower end  22   b  of the vertical slot  22   b.    
      Beyond suppressing the vibration of the operation lever  32 , the spring  50  also resiliently supports downwardly the operation lever  32  pivoting to the “first position” X or the “second position” Y as shown in  FIGS. 5B and 5C , thereby serving to accelerate the pivoting velocity of the operation lever  32 . As a result, the carriage  20  is caused to move in a high velocity.  
      Meanwhile, the spring  50  is supported by the frame  1   a  at its one end as shown in  FIG. 2 , wherein the supporting point is aligned to the rotational center  32 , that is, to the vertical lower part of the output shaft  30   a  of the forward/reverse motor  30 .  
      This arrangement is provided for several purposes as follows: to render the spring  50  to have the longest tensioning length L2 when it supports the operation lever  32  positioned at the middle position between the “first position” X and the “second position” Y as shown in  FIG. 5A , so that larger elastic force is applied to the operation lever  32  so as to cause the operation lever  32  to more rapidly pivot, and to render the spring  50  to have the shortest tensioning length L1, L3 when it supports the operation lever  32  positioned at the “first position” X or the “second position” Y, so that relatively smaller elastic force is applied to the operation lever  32  so as to minimize the impact against the lower end  22   b  of the slot  22   a.    
      Referring to  FIGS. 2 and 3  again, the inventive tool magazine further comprises a pair of shock-absorbing pads  60  each being provided at the lower end  22   b  and upper end  22   c  of the vertical slot  22   a  of the carriage  20 . The shock-absorbing pads  60  are arranged in such a way that they come into contact with the rolling roller  32   a  of the operation lever  32  pivoting from the “first position” X to the “second position” Y, or from the “second position” Y to the “first position” X. Consequently, the shock-absorbing pads  60  prevent the rolling roller  32   b  of the operation lever  32 , which rapidly pivots, from vibrating when the roller  32   b  runs into the lower end  22   b  and the upper end  22   c  of the vertical slot  22   a  of the carriage  20 .  
      Next, the functional action of the invention configured as described above is described with reference to  FIGS. 2 and 5 A to  5 C. At first, if a tool exchanging command is given in the state in which the carriage  20  is positioned at the “remote position” C as shown in  FIG. 2 , the forward/reverse motor  30  of the driving means is operated and forwardly rotated.  
      Then, as the forward/reverse motor  30  is forwardly rotated, the operation lever  32  is also forwardly rotated as shown in  FIG. 5A , thus moving from the “first position” X to the “second position” Y. At this time, as the operation lever  32  moves from the “first position” X to the “second position” Y, the carriage  20  also moves from the “remote position” C toward the “proximate position” D, and as the carriage  20  moves from the “remote position” C toward the “proximate position” D, the tool magazine supported on the carriage  20  also moves toward the spindle  3 .  
      Then, as the operation lever  32  continuously pivots in the forward direction and arrives at the “second position” Y as shown in  FIG. 5B  and the carriage  20  arrives at the “proximate position” D, the tool magazine  1  supported on the carriage  20  is aligned to the lower part of the spindle  3 . In this state, the tool T supported on the spindle  3  is in the state of being exchangeable.  
      Meanwhile, if the operation lever  32  arrives at the “second position” D, the second detection sensor  42  detects it and input a detection signal to the controller  44 . Then, the controller  40  recognizes that the operation lever  32  is located at the “second position” and stops the operation of the forward/reverse motor  30  in response to the inputted signal. Accordingly, the operation lever  32  is fixed at the “second position” Y, as a result of which the carriage  20  is also fixed at the “proximate position” D.  
      Meanwhile, if the exchange of the tool T is completed, the forward/reverse motor  30  of the driving means is reversely rotated. Then, as the forward/reverse motor  30  is reversely rotated, the operation lever  32  secured to the forward/reverse motor  30  also reversely pivots as shown in  FIG. 5C , thus moving from the “second position” Y to the “first position” X. At this time, as the operation lever  32  moves from the “second position” Y to the “first position” X, the carriage  20  also moves from the “proximate position” D toward the “remote position” C, and as the carriage  20  moves from the “proximate position” D toward the “remote position” C, the tool magazine  1  supported on the carriage  20  is moved away from the spindle  3 .  
      Then, if the operation lever  32  continuously pivots in the reverse direction and arrives at the “first position” X, the carriage  20  also arrives at the “remote position” C, and as the carriage  20  arrives at the “remote position” C, the tool magazine  1  supported on the carriage  20  is completely separated from the spindle  3 .  
      Meanwhile, if the operation lever  32  arrives at the “first position” X and the first sensor  40  detects this, the sensor  40  inputs the detection sensor to the controller  44 . Then, the controller  44  recognizes that the operation lever  32  is positioned at the “first position” X and stops the operation of the forward/reverse motor  30 . Consequently, the operation lever  32  is fixed at the “first position” X, as a result of which the carriage  20  is also fixed at the “remote position” C.  
      As the inventive tool magazine feeder for an automatic tool changer configured as described above fees the tool magazine using a motor, it is possible to prevent the tool magazine from abruptly moving and abruptly stopping due to the unstable supply of compressed air as in the prior art. In addition, because the tool magazine can be moved without being supplied with compressed air, the movement of the tool magazine does not affect the pressure and supplied amount of the compressed air supplied to another pneumatic device. Furthermore, because the tool magazine can be moved to a correct position each time without noise and impact, the tool exchange can be precisely controlled. Moreover, the construction of the inventive tool magazine feeder is very simple, it is possible to reduce the manufacturing costs thereof and it is simple and convenient to assemble or repair the tool magazine feeder.  
      While the invention has been shown and described with reference to certain preferred embodiments thereof for the purpose of exemplification, the present invention is not limited to the specific embodiment. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.