Abstract:
The present invention provides a mechanical press with a low height. A sliding guide mechanism and a position adjusting mechanism are provided on the upper and lower sides of an adjustor member, respectively. The sliding guide mechanism converts the rotating motion of an eccentric part of a crankshaft into a reciprocating linear motion and is provided above the adjustor member. The position adjusting mechanism adjusts the position of the slide adjustment and is provided below the adjustor member.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a mechanical press with a low height.  
         BACKGROUND OF THE INVENTION  
         [0002]    A typical mechanical press is shown in FIG. 6 and includes an eccentric part  8   a  of a crankshaft which is connected by a connecting rod  23  to a slide  3 . An adjustor screw  24  for adjusting the slide  3  is located between the connecting rod  23  and the slide  3 . The distance between the crankshaft and the slide  3  cannot be shortened due to the presence of the connecting rod  23 . Therefore, the total height of the mechanical press must include the height of the connecting rod  23 .  
           [0003]    Japanese Laid-Open Patent Number 55-48500 discloses a mechanical press without a connecting rod. The height of the mechanical press is lower since there is no connecting rod. However, this mechanical press lacks an adjustor screw for slide adjustment, and a mechanical press is inconvenient to operate without an adjustor screw.  
           [0004]    Japanese Laid-Open Patent Publication Number 06-269996 discloses a bushing and a slide which are fitted to the eccentric part of a crankshaft. The slide slides inside a connecting rod which is guided in the vertical direction by a guide bushing provided on a crown part. The connecting rod and the slide are connected by a die height adjusting mechanism. The slide is prevented from being raised above the guided part of the connecting rod since the connecting rod is guided by the crown part. Therefore, the height of the machine cannot be lowered.  
           [0005]    Japanese Laid-Open Patent Publication Number 57-14499 discloses a guide plate which is guided by a guide. The slide cannot move higher than the guide, and the distance between the crankshaft and the slide cannot be shortened. It would be difficult to lower the height of this mechanical press.  
           [0006]    A connecting rod or a member associated with the connecting rod prevents lowering the height of a mechanical press. Press operations are difficult to perform on mechanical presses whose height can be lowered.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention provides a mechanical press with a low height that is convenient to use. A sliding guide mechanism and a position adjusting mechanism are provided on the upper and lower sides of an adjustor member, respectively. The sliding guide mechanism converts the rotating motion of an eccentric part of a crankshaft into a reciprocating linear motion and is provided above the adjustor member. The position adjusting mechanism adjusts the position of the slide and is provided below the adjustor member.  
           [0008]    A sliding guide mechanism converts the rotating motion of the eccentric part of the crankshaft into a linear reciprocating motion by working with the slide of the mechanical press. The position adjusting mechanism is prevented from rotating with respect to the slide. However, the position adjusting mechanism can advance and retreat with respect to the slide.  
           [0009]    The position adjusting mechanism can be a screw mechanism which comprises a screw shaft on the adjustor member and a nut which screws onto the screw shaft. The nut can rotate and is prevented from moving relative to the slide.  
           [0010]    The sliding guide mechanism can be provided on an upper side of the position adjusting mechanism. The sliding guide mechanism comprises a slider that connects to the eccentric part of the crankshaft and a framework which houses the slider in a freely sliding manner.  
           [0011]    The slider can be separated and can comprise an upper slider which connects to an upper side of the eccentric part of the crankshaft and a lower slider which connects to a lower side of the eccentric part of the crankshaft.  
           [0012]    The objects, features, and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a front view of a partial cross-section of a mechanical press of the present invention.  
         [0014]    [0014]FIG. 2 is a left side view of a partial cross-section of a mechanical press of the present invention.  
         [0015]    [0015]FIG. 3 is a rear view of a partial cross-section of a mechanical press of the present invention.  
         [0016]    [0016]FIG. 4 is an enlarged view of the principal parts of a mechanical press of the present invention.  
         [0017]    [0017]FIG. 5 is a perspective view of the principal parts of a mechanical press of the present invention.  
         [0018]    [0018]FIG. 6 is a front view of a partial cross-section of a mechanical press of the prior art with a connecting rod. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]    A slide  3  is provided on a frame  2  of a mechanical press  1  as shown in FIG. 1 so that the slide  3  can be raised and lowered. A bolster  4  is attached to the frame  2  so that it is positioned opposite to the slide  3 . A vibration-proof piece  5  is attached to the lower end of the frame  2  and blocks the vibration of the mechanical press  1  at the foundation.  
         [0020]    The slide  3  is guided by a slide guide  18  and is raised and lowered with respect to the frame  2 . The slide  3  is pulled up by a balancer  25  which is constructed from an air cylinder device. The balancer  25  balances the weight of the slide  3  and an upper mold which is attached to the lower surface of the slide  3 .  
         [0021]    A crankshaft  8  is provided on the frame  2  as shown in FIG. 2 and is supported rotatably by a bearing provided on the frame  2 . The crankshaft  8  is positioned in the front-back direction with respect to the frame  2 .  
         [0022]    A main gear  9  is attached to the crankshaft  8 . A flywheel  11  is provided on the frame  2  and is rotated by a motor (not shown). A pinion gear  10  is formed on a shaft provided on a clutch brake located inside the flywheel  11 . The pinion gear  10  engages with the main gear  9 .  
         [0023]    The crankshaft  8  is rotated by a driving mechanism which is constructed from the motor, the flywheel  11 , the clutch brake, the pinion gear  10 , the main gear  9 , and the like.  
         [0024]    The flywheel  11  has a relatively large diameter as shown in FIG. 3. Therefore, the flywheel  11  is placed near the end of the crankshaft  8 . The flywheel  11  lowers the height of the frame  2 , thereby lowering the height of the mechanical press  1 .  
         [0025]    A sliding guide mechanism  6  and a position adjusting mechanism  7  are provided together on an adjustor member  12  as shown in FIG. 4. The sliding guide mechanism  6  is provided on the upper side of adjustor member  12 , and the position adjusting mechanism  7  is provided on the lower side of adjustor member  12 . A cap  13  interposes spacers  15  and is attached to the adjustor member  12  by a bolt  14 . A framework, which has a space in the center, is created with the adjustor member  12 , the spacers  15 , and the cap  13 .  
         [0026]    An eccentric part  8   a  of the crankshaft  8 , an upper slider  16 , and a lower slider  17  are housed in the space in the center of the framework. The upper slider  16  and the lower slider  17  are joined above and below the eccentric part  8   a  of the crankshaft  8 , respectively. The upper slider  16  and the cap  13  can slide freely, and the lower slider  17  and the adjustor member  12  can slide freely. The sliding guide mechanism  6  is constructed from the upper slider  16 , the lower slider  17 , the adjustor member  12 , the cap  13 , the spacer  15 , and the like. The upper slider  16  and the lower slider  17  move horizontally relative to each other with respect to the framework.  
         [0027]    The slider can be separated and can comprise the upper slider  16  and the lower slider  17 . There are advantages to a separated slider in contrast to a unitary slider. Additional space for a bolt to unify the upper and lower sliders is unnecessary, and therefore, the slider can be narrower. Furthermore, the clearance inside and outside the slider can be halved.  
         [0028]    A nut  21  is screwed onto a screw shaft  12 a which is formed on the lower end of the adjustor member  12 . The nut  21  can rotate on the slide  3 , but the vertical movement of the nut  21  is restricted. The nut  21  is retained on the slide  3  by a retainer  22 . A worm gear  20  is formed on the perimeter of the nut  21  and engages a worm shaft  19 . The worm shaft  19  rotates on the slide  3  and is rotated by a motor (not shown). The position adjusting mechanism  7  is constructed by the screw shaft  12 a, the nut  21 , the worm gear  20 , the worm shaft  19 , and the like. The position adjusting mechanism  7  corresponds to the slide adjusting means.  
         [0029]    The position adjusting mechanism  7  uses a screw mechanism, but it can also use hydraulic pressure. A hydraulic cylinder can be provided on the lower side of the adjustor member  12 . The adjustor member  12  can advance or retreat with respect to the slide  3  by controlling the amount of oil in the hydraulic cylinder. Alternatively, a taper block can be placed under the adjustor member  12  so that the adjustor member  12  can advance or retreat with respect to the slide  3 .  
         [0030]    The adjustor member  12  is guided by the slide  3  in order to prevent accidental rotation. It is necessary to prevent changes in the slide adjustment amount due to accidental rotation of the adjustor member  12  during operation. Guide hole  3   a , which can be a square-shaped hole in the slide  3 , allows the adjustor member  12  to move in the vertical direction with respect to the slide  3  and prevents the rotation of the adjustor member  12 . The adjustor member  12  is guided directly by the slide  3 . However, there can be an insertion in the slide  3  that can be used to guide the adjustor member  12 .  
         [0031]    [0031]FIG. 5 is a perspective view of a mechanical press  1  with a partial cutaway of slide  3 . The slide  3  is at the bottom dead center position in FIG. 5 since the crank angle is 180°.  
         [0032]    The worm gear  20  and the nut  21  rotate when the worm shaft  19  rotates. The adjustor member  12  is raised and lowered with respect to the slide  3  by the screw mechanism. The displacement amount of the adjustor member  12  equals the slide adjustment amount of the mechanical press  1 .  
         [0033]    A member such as the connecting rod of the prior art is unnecessary. Therefore, the slide can be positioned higher by a distance corresponding to the length of the unnecessary connecting rod, and the height of the mechanical press can be lowered. Additionally, the vertical and horizontal rigidity of the mechanical press increases. Therefore, the mechanical press does not require a tall housing. Furthermore, the press operation is precise.  
         [0034]    Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments. Various changes and modifications may be effected by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.