JP2012066299A - Press device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact and inexpensive press device capable of exhibiting stable dimensional accuracy after working of a workpiece, capable of reducing adjustment work and adjustment time of a die, and capable of increasing a working speed.SOLUTION: The press device 100 includes: a connecting rod 2 having an end pivottaly connected to a first fulcrum 10 rotating around a center axis of a flywheel 1; an upper link rod 3 pivotally connected to the another end of the connecting rod 2 to form a second fulcrum 11 and pivotally arranged to an upper end of the press device 100; a lower link rod 4 pivotally connected to the another end of the connecting rod 2 as the second fulcrum 11 and pivotally arranged on a slider 6 of the press device 100; and a ram 7 vertically operated by the slider 6. In the press device 100, the bottom dead center of the ram 7 is generated for plural times while the first fulcrum 10 rotates once on the flywheel 1.

Description

  The present invention relates to a press apparatus using a knuckle link mechanism.

  As shown in FIG. 1, the mechanical crank press facility of the conventional structure includes a flywheel 1, a clutch brake unit (not shown), a connecting rod 2, a slider 6, a slide guide 5, a ram 7, a bolster 8, a drive source (see FIG. (Not shown). The power is continuously accumulated in the flywheel connected to the drive source, and the power is slid through the connecting rod 2 in which the energy of the flywheel is rotatably fixed to the fulcrum 10 around the rotation axis 1 by the clutch brake unit. 6 to move the ram 7 up and down. The mold mounted on the bolster 8 is subjected to plastic processing by applying the force of the ram 7.

  The movement curve of the conventional ram 7 is a sine wave as shown by the “crank press” line in FIG. 4, and the maximum load for machining at the bottom dead center (also called the lowest point) where the ram 7 descends most. Is a mechanism that generates instantaneously.

  In the crank press process, the material is pressed, punched and bent at about 10 degrees before the bottom dead center (crank angle) shown in FIG. 4, that is, about 170 degrees, and bent and crushed at the bottom dead center. Processing to make the shape. The region around ± 3 ° of the bottom dead center, that is, around 177 to 183 ° is the processing region of the original finish of the press, but since it has a mechanism that instantaneously generates the maximum load in the vicinity, the processing time Is very short. Therefore, in order to perform plastic working in bending and crushing thick plate materials, the strain rate cannot follow and the deformation applied to the material returns slightly to the original, so the crushing amount cannot be processed as intended, and stability In many cases, variations in dimensional accuracy of products occur.

  In order to increase the accuracy at the bottom dead center of the crank press process, various press apparatuses as described below have been proposed.

Patent Document 1 includes a link mechanism including a pair of levers connected to each other so as to bend and stretch by the rotational movement of the crankshaft, and an eccentric shaft that is rotatably arranged around an axis extending in a horizontal direction on the frame. In addition, there is provided an apparatus in which an eccentric shaft and a link mechanism are connected, one and other levers are connected to a crankshaft and a slide, respectively, and the crankshaft and the eccentric shaft are rotated by separate drive sources.
Patent Document 2 proposes a press device having two bottom dead centers. In the press working method in which the drawing process and the barrel molding process are performed in order, the drawing process is performed by pressurizing to the first bottom dead center with the drawing mold, the cylinder molding process is changed to the cylinder molding mold, and the second bottom Molded by pressurizing to the dead point.

  Patent Document 3 discloses a detector that detects the relative distance between the lower surface of the slide and the upper surface of the bolster at the bottom dead center in the press operation state, and the slide bottom dead center that controls the position adjusting device so that the relative distance falls within a predetermined range. An automatic position correction device is provided.

JP 2003-48099 A JP 2008-105094 A JP 60-141399 A

  As described above, in the crank press processing, the processing time in the processing area of the original finish near the bottom dead center is very short. Therefore, in order to perform plastic working in bending and crushing thick plate materials, the strain rate cannot follow and the deformation applied to the material returns slightly to the original, so the crushing amount cannot be processed as intended and stability is improved. In many cases, chipping and variations in the dimensional accuracy of the product occur, and crank pressing is not suitable for processing a product with high required accuracy.

  In Patent Document 1, it is possible to adjust the position of the bottom dead center, but the point that the machining time near the bottom dead center is very short is not solved. Further, although an apparatus is provided in which the crankshaft and the eccentric shaft are rotated by separate drive sources, the use of separate drive sources is expensive.

  Patent Document 2 proposes two bottom dead centers, but since the first bottom dead center and the second bottom dead center perform different processes, the processing time near the bottom dead center is very short. The point has not been resolved.

  In Patent Document 3, the accuracy of the position of the bottom dead center can be increased by the position adjusting device, but the point that the machining time in the vicinity of the bottom dead center is very short is not solved.

  In order to solve the above problems, servo presses and high-performance knuckle link presses have been developed.

  However, these press facilities are expensive, and in order to maintain product quality, likelihood is required for the press capacity. In addition, there is a case where the demand for high-speed processing cannot be satisfied due to the response by large equipment, and the strain rate of the material cannot be followed with a product with high processing degree, and the material is cracked when strong processing is performed once. Or excessive strain may remain, resulting in aging or destruction. In order to avoid this problem, it may be possible to perform the press work in a plurality of times, but it takes time.

  In view of such points, the present invention increases the processing time near the bottom dead center of the press device, reduces plastic deformation of the workpiece, stabilizes dimensional accuracy after processing, and is a compact and inexpensive press. An object is to provide an apparatus.

  In order to solve the above problems, the present invention provides a drive source, a clutch brake unit connected to the drive source and transmitting power, a flywheel connected to the clutch brake unit and rotatably disposed, A connecting rod having an end rotatably arranged at a first fulcrum around the center axis of the flywheel, and an upper end of a press device connected to the other end of the connecting rod and a second fulcrum so as to be rotatable. An upper link rod rotatably disposed on the other end of the connecting rod and a second fulcrum, and a lower link rod rotatably disposed on a slide of a press device; A press machine having a ram that moves up and down by a slider, while the first fulcrum makes one turn on the flywheel. But to provide a press apparatus for generating a plurality of times.

  Further, the first fulcrum of the flywheel is the first position closest to the vertical straight line position of the upper link rod and the lower link rod, and the second fulcrum of the connecting rod exceeds the vertical straight line position. Can be a feature.

  Further, the first fulcrum of the flywheel is at a second position above the first position, the second fulcrum of the connecting rod is on the vertical straight line position, and the flywheel first The third fulcrum of the connecting rod may be on the vertical straight line at the third position where the fulcrum of one is below the first position.

  According to the present invention, the degree of pressurization and pressurization time can be set to desired values, plastic deformation can be reduced, and stable processing can be performed up to the processing end point.

General crank press device. The knuckle link press apparatus of a present Example. The press process of the knuckle link press apparatus of a present Example. The lowering curve of the ram of a present Example and a comparative example, and the ram curve of a general crank press.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 2 shows a press apparatus using the knuckle link press mechanism of this embodiment. The press device 100 includes a flywheel 1, a clutch brake unit (not shown), a connecting rod 2, an upper link rod 3, a lower link rod 4, a slide guide 5, a slider 6, a ram 7, a bolster 8, an expansion mechanism 9, and a support. It consists of a plate 12 and a drive source (not shown).

  The end of the connecting rod 2 is rotatably installed at a first fulcrum 10 around the rotation axis of the flywheel 1, and the other end of the connecting rod 2 is the end of the upper link rod 3 and the lower link rod 4. And the second fulcrum 11. The other end of the upper link rod 3 is rotatably installed on the fulcrum 12 at the upper end of the press device 100, and the other end of the lower link rod 4 is rotatably installed on the slider 6 of the press device 100. Has been.

  Similar to the structure of a general crank press, the flywheel 1 is rotated clockwise by a clutch brake unit (not shown) connected to a drive source (not shown) and transmitting power. The rotational movement of the flywheel 1 is converted into the vertical movement of the slider 6 via the connecting rod 2 and the link rods 3 and 4 to move the ram 7 up and down. In this way, plastic working is performed by applying the force of the ram 7 to the mold mounted on the bolster 8. The above is an explanation of the operation of a normal knuckle link press mechanism.

  A crank angle θ is defined as an angle formed by a line passing through the center of the flywheel and passing through the first fulcrum 10 and the center of the flywheel with respect to a virtual line horizontal to the ground surface.

  In the press apparatus using the knuckle link press mechanism of the present embodiment, the length of the connecting rod 2 can be made variable by using an expansion / contraction mechanism 9 such as a screw, and can be arbitrarily set.

  In the embodiment, the length of the connecting rod 2 is such that the upper link rod 3 and the lower link rod 4 reach the position where the connecting portion 11 of the link rods 3 and 4 exceeds the vertical straight line position at the bottom dead center position. Set. In this embodiment, the lengths of the upper link rod 3 and the lower link rod 4 are equal, but the lengths of the link rods 3 and 4 are made different depending on the material of the molding object and the shape after molding. Can do. By setting the length in this way, the ram 7 arrives at the bottom dead center twice while the connecting rod 2 makes one rotation around the rotation axis of the flywheel 1 (one step). Details of the operation of the structure will be described below in comparison with a normal knuckle link press apparatus.

  FIG. 3 shows a pressing process according to this embodiment. From state S1 (the state shown in FIG. 3 (1)), the first fulcrum 10 rotates clockwise (or reverse rotation) as the flywheel rotates, and the connecting rod 2 and the link rods 3 and 4 are interposed. Then push down the ram 7. In the state S2 (the state shown in FIG. 3 (2)), since the press work has not been performed yet, the state descends at a high speed.

  State S3 (the state shown in FIG. 3 (3)) is a second position in front (upward) where the first fulcrum 10 of the flywheel is closest to the vertical straight line position 15 of the link rods 3 and 4, that is, the main crank. The angle θ is not reaching 180 degrees, the link rods 3 and 4 are on the vertical straight line 15, and the second fulcrum 11 of the connecting rod 2 is on the straight line. At this time, the ram 7 arrives at the bottom dead center and performs plastic working. Plastic working is performed at the stroke position in the vicinity. In a normal knuckle link press device, the ram 7 has not yet reached the bottom dead center at this time.

  Further, in the state S4 (the state shown in FIG. 3 (4)), the first position where the first fulcrum 10 of the flywheel is closest to the vertical straight line position 15 of the link rods 3 and 4, that is, the main crank angle θ is The second fulcrum of the connecting rod 2 moves beyond the vertical straight line position 15 of the link rods 3 and 4. At this time, the ram 7 rises slightly from the bottom dead center. In a normal knuckle link press apparatus, the ram 7 arrives at the bottom dead center only during one process (that is, during one cycle in which θ is rotated at 0 to 360 degrees).

  After the state S4, the first fulcrum 10 of the flywheel is at a third position (not shown) below the first position, and the link rods 3 and 4 are again on the vertical straight line position 15 and connected. The second fulcrum 11 of the rod 2 is on the straight line. At this time, the ram 7 arrives at the bottom dead center and performs plastic working. In a normal knuckle link press apparatus, the ram 7 is still away from the bottom dead center at this time.

  After the ram 7 passes the bottom dead center, the state 7 returns to the top dead center (also referred to as the top point) through the state S5 (the state shown in FIG. 3 (5)), and the operation of one step is completed.

In the state of S4, it was confirmed by trial calculation that if the distance over which the fulcrum 11 exceeds the vertical straight line position 15 of the link rods 3 and 4 is 5 mm or more with respect to the ram stroke amount of 100 mm, the effect of pressing twice is effectively obtained. Thereby, it is confirmed that the compressive strain of the material during plastic processing is relaxed by about 1000 × 10 ⁻⁶ strain, and the flow deformation of the material during processing can be easily suppressed.

  FIG. 4 shows the descending curve of the ram. The vertical axis represents the ram descending position (mm), and the horizontal axis represents the crank angle. The crank angle θ (degrees) is an angle formed by a line passing through the center of the flywheel and passing through the first fulcrum 10 and the ground surface and the center of the flywheel with respect to a virtual line horizontal to the ground surface. The ram descending position (mm) indicates the distance from the ram reference line upward, with the ram's bottom dead center as the reference line.

  The ram stroke is 100 mm, the length of the link rods 3 and 4 is 200 mm, the distance from the center axis of the flywheel to the vertical straight line position 15 of the link rods 3 and 4 is 1050 mm, and the length (L) of the connecting rod is It is a result at the time of changing to 1005 mm (Example 1), 1010 mm (Example 2), and 1015 mm (Example 3). As Comparative Example 1, a conventional knuckle link press (connecting rod length L of 1000 mm) was shown.

  In the conventional crank press working (Comparative Example 2), the ram bottom dead center is reached at a crank angle of 180 degrees (first position) on the horizontal axis, and the movement follows a sinusoidal curve. At the same time as the position of the dead center shifts, the ram descent stop range near the bottom dead center (180 ° ± 30 °) becomes wider. In particular, as in Example 2 and Example 3, when the length of the connecting rod 2 is increased, two ram bottom dead points appear, and it can be seen that the press load is reduced between the bottom dead points.

  In the case of Example 1, in particular, since the stationary time near the bottom dead center of the ram is long, the deformation speed of the workpiece can be followed, the plastic deformation can be reduced, and stable machining can be performed up to the machining end point. In addition, since the processing at the bottom dead center can be performed twice in processing such as bending and crushing, the finished shape can be stabilized. Furthermore, by making the length of the connecting rod 2 variable, it is possible to obtain a desired degree of pressurization and quantitatively determine the optimum press conditions. That is, the processing conditions can be extended to a more severe range.

  As for the overall height of the device, the conventional crank press device has a vertical layout of the flywheel 1 to bolster 8, which increases the height of the equipment, and is subject to restrictions on transportation and buildings. However, by adopting the structure of the present embodiment, the height of the entire apparatus can be reduced, and the above-mentioned limitation is not imposed.

  An electric motor is generally used as the drive source of this embodiment, but an air cylinder or a hydraulic cylinder may be used.

  In this embodiment, the ram bottom dead center is generated at two locations by making the length of the connecting rod 2 variable. However, the length of the link rods 3 and 4 can be changed in addition to the method of changing the length of the connecting rod 2. Even if it is changed, the same effect can be obtained, and the same effect can be obtained even if the upper and lower fulcrum positions of the link rods 2 and 3 are changed without changing the length.

  Further, the connecting rod can be made longer than the upper link rod and the lower link rod for the purpose of not overloading mechanically.

  DESCRIPTION OF SYMBOLS 1 ... Fly wheel, 2 ... Connecting rod, 3 ... Upper link rod, 4 ... Lower link rod, 5 ... Slide guide, 6 ... Slider, 7 ... Ram, 8 ... Bolster, 9 ... Extending mechanism, 10 ... First fulcrum , 11 ... second fulcrum, 12 ... fulcrum of upper link rod, 13 ... fulcrum of lower link rod, 14 ... support plate, 15 ... vertical straight line position of upper link rod and lower link rod, 100 ... pressing device.

Claims (3)

A drive source, a clutch brake unit coupled to the drive source and transmitting power;
A flywheel connected to the clutch brake unit and rotatably disposed;
A connecting rod having an end rotatably arranged at a first fulcrum around the center axis of the flywheel;
An upper link rod rotatably connected to the other end of the connecting rod at a second fulcrum and rotatably arranged at the upper end of the press device;
A lower link rod rotatably connected to the other end of the connecting rod at a second fulcrum and rotatably arranged on the slide of the press device;
A ram that moves up and down by the slider;
In a press apparatus having
A pressing device in which the bottom dead center of the ram is generated a plurality of times while the first fulcrum rotates once on the flywheel.   The first fulcrum of the flywheel is a first position closest to the vertical straight line position of the upper link rod and the lower link rod, and the second fulcrum of the connecting rod exceeds the vertical straight line position. The press apparatus according to claim 1. The first fulcrum of the flywheel is at a second position above the first position, and the second fulcrum of the connecting rod is on the vertical straight line position;
The first fulcrum of the flywheel is a third position below the first position, and the second fulcrum of the connecting rod is on the vertical straight line position. Press equipment.

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