JPH0310439B2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a press machine such as a power press,
In particular, the present invention relates to a press machine equipped with a balance weight for balancing the unbalanced inertial force of a slide, which is a moving body.

Prior Art and Problems to be Solved by the Invention In press machines, a balancer is used to balance the unbalanced inertial force of the slide, which is a reciprocating body, to suppress the occurrence of primary vibrations associated with press operation. As this balancer, one using a balance weight, one using a spring, one using compressed air pressure, etc. are known. By the way, the mold for attaching the semiconductor to the slide has different dimensions and weights depending on the product specifications, so the balancer must be balanced to match the unbalanced inertia between the slide and the specific mold. Even if the force is set, if different molds are used, the inertia force will not be balanced.

Therefore, it is necessary to readjust the balancer every time the mold used is changed, and replacing the balance weight is particularly troublesome for models that use balance weights, which hinders productivity. . For example, Japanese Patent Application Laid-open No. 192298/1983 has been proposed to solve this problem.

On the other hand, the slide is expected to have sufficient rigidity as a structural member that receives work loads, and to be lightweight as a reciprocating body. However, ensuring rigidity and reducing weight are contradictory requirements, and mechanical designers struggle to find a compromise between them.

However, in a trunk press that has a structure in which the rotation of the crankshaft is transmitted to the slide via a connecting rod and the slide is reciprocated along a guide member of the frame, it is necessary to ensure a certain length of the connecting rod.
The drive system that converts rotational motion into reciprocating motion using two rotating pairs and joints is complex, and disadvantages include the difficulty of ensuring the rigidity of the drive system, the weight of the moving body, and the disadvantages for high-speed operation. have.

The present invention was created against this technical background, and its main purpose is to balance the unbalanced inertial force of the slide including the mold in response to changes in the weight (or mass) of the mold. It is an object of the present invention to provide a dynamic balance mechanism for a press machine that can easily perform the following.

Another object of the present invention is to simplify the structure of the drive system, ensure the rigidity of the drive system, and reduce the weight of the moving bodies that make up the drive system, thereby improving the precision of the press machine and enabling high-speed operation of the machine. The goal is to make it possible.

Means for Solving the Problems and Their Effects The object is to provide a press machine having a dynamic balance mechanism, in which an upper die (punch) is paired with a lower die disposed on the bed of a frame via a bolster. A slide carrying a slide (including a The slide is supported by a frame via a bearing so as to be freely displaceable in the vertical direction, and the upper half of the slide is formed as a yoke;
A sliding block having upper and lower surfaces parallel to the upper and lower inner wall surfaces of the yoke, both of which are formed as horizontal surfaces, is housed in the yoke so as to be relatively displaceable in the horizontal direction via upper and lower bearings. An eccentric drive shaft supported by the frame and extending through the yoke also passes through a circular central opening formed in the sliding block, and the eccentric portion of the eccentric drive shaft is rotatably connected to the central opening via a bearing. A balance weight for balancing the unbalanced inertia of the slide, which is a reciprocating body, is swingably connected to the slide at one end, passes through the cylinder of the fluid pressure cylinder device, and extends in both directions. The cylinder of the fluid pressure cylinder device, which is attached to the other end of the piston rod, is swingably supported by a support rod in an upright position that is swingably supported by the frame, and is also supported by the piston using fluid pressure. This is achieved by providing a press machine (hereinafter simply referred to as a press) which is displaceable relative to the slide and whose balance weight is configured to move up and down in an antiphase relationship with respect to the slide.

The eccentric part of the eccentric drive shaft, the sliding block, and the yoke of the upper half of the slide constitute a yoke cam, and when the eccentric drive shaft rotates, the sliding movement is allowed only in the lateral direction relative to the yoke. A yoke (ie, a slide) reciprocates vertically through the block. At this time, the slide is guided by the frame via bearings at an upper guide shaft portion erected at its upper end and at least two lower guide shaft portions vertically provided at its lower end.

In addition, as the slide reciprocates in the vertical direction, the piston rod swings about the connection point between the cylinder of the fluid pressure cylinder device and the support rod as a fulcrum, and the balance weight attached to the piston rod moves in the opposite direction to the slide. move up and down in the direction. The cylinder of the fluid pressure cylinder device is movable with respect to the piston, and when the weight of the upper mold attached to the slide is large, the cylinder is adjusted and displaced toward the slide side, and when the weight of the upper mold is small, the cylinder is adjusted and displaced. All you have to do is adjust the cylinder to the anti-slide side.
It is possible to balance the unbalanced inertial force of the slide including the sliding block.

Example The illustrated embodiment will be described below.

FIG. 1 is a longitudinal sectional view of the press 1 seen from the front, and FIG. 2 is a partial longitudinal sectional view of the press 1 seen from the side. The frame of the press 1 is composed of a bed 2 as a lower member, and a crown 4 as an upper member in which a column 5 and a side wall 6 are integrated with a top wall 8. They are integrally screwed together. A cylindrical sliding bearing 7 is fitted into the through hole formed in the front and rear side walls 6, 6 when viewed from the front.
An eccentric drive shaft 12 having an eccentric portion 13 having a circular cross section is supported through the sliding bearing 7. In the figure,
L ₁ indicates the rotation center axis of the eccentric drive shaft 12, and L ₂
indicates the center axis of rotation of the eccentric portion 13. This eccentric drive shaft 12 is driven and rotated by a motor via a well-known power transmission mechanism (not shown).

The slide 14 is arranged in the center of the frame interior space, and an upper guide shaft 18 erected at its upper end fits into a cylindrical sliding bearing 9 attached to the top wall 8 of the crown 4, and a lower end At least two vertically disposed lower guide shafts 19 are fitted into cylindrical slide bearings 3 attached to the bed 2. The axes of the upper and lower guide shafts 18 and 19 are both parallel to the vertical line, and the slide 14 reciprocates in the vertical direction (up and down) due to the fitting relationship between the upper and lower guide shafts 18 and 19 and the sliding bearings 9 and 3. verb) to do.

Further, the upper half of the slide 14 is formed as a yoke 15, and its upper inner wall surface 16 and lower inner wall surface 17 are both horizontal planes intersecting the vertical line at right angles. The eccentric drive shaft 12 is connected to this yoke 15.
In addition to penetrating through the yoke 15, it also passes through the roughly rectangular cylinder-shaped sliding block 20 housed in the yoke 15. Upper surface 22 and lower surface 23 of sliding block 20
are horizontal planes parallel to the upper inner wall surface 16 and lower inner wall surface 17 of the yoke 15, and the surfaces 22, 16
Caged roller bearings 24 and 25 are interposed between the surfaces 23 and 17, respectively.
5, the sliding block 20 can be relatively displaced in the front-back direction (see arrow A) inside the yoke 15.

The sliding block 20 has a circular central opening 21 in which a caged roller bearing 2 is inserted.
The eccentric portion 13 of the eccentric drive shaft 12 is inserted through the eccentric portion 6 . Between the sliding block 20 with roller bearings 24 and 25 interposed therein and the yoke 15, and between the sliding block 20 with the roller bearings 26 interposed therebetween and the eccentric portion 13.
There is no room for relative displacement in the vertical direction between them, and they are assembled in a tight fit state.

The slide 14, which is reciprocated in the vertical direction by the rotation of the eccentric drive shaft 12, carries an upper mold 27 on its lower end surface, and connects the lower mold 29 and the upper mold 27, which are fixed to a bolster 28 on the bed 2. Pressing is performed through cooperative action.

Further, dynamic balancing mechanisms 30, 30 are arranged symmetrically on the left and right sides of the slide 14. The main component of the dynamic balance mechanism 30 is the balance weight 3
1, and a fluid pressure cylinder device 33 supported by a support rod 32. The fluid pressure cylinder device 33 consists of a pair of ear shafts 35, a cylinder 34 having fluid supply and discharge ports 36 and 37, a piston 38, and a piston rod 39 integrated with the piston 38, and is installed between the side walls 6 and 6 of the frame. a pair of support rods 32 whose lower ends are swingably supported by a support shaft 11;
The cylinder 34 is supported by the support rod 32 in an upright position, with the upper end of the cylinder 34 swingably fitting into a pair of ear shafts 35 . Both ends of the piston rod 39 are swingably connected to the slide 14 and the balance weight 31, and the connection relationship and the support shaft 11
The load of the balance weight 31 is supported by the connection between the support rod 32 supported by the cylinder 34. The cylinder 34 has its ports 36, 37
By supplying and discharging fluid through the lever, it can be displaced relative to the piston 38, and therefore the position of the ear shaft 35, which is the fulcrum of the lever, is variable.

In addition to the support rod 32, a pair of links 41 are swingably supported on the support shaft 11, and one end of the link 41 and the sliding block 20 form the link 40 that freely passes through the side wall of the slide 14. The other end of the link 41 and the balance weight 31 are connected by a pair of links 42. This linkage is for dynamic balance of the sliding block 20.

The press 1 operates as follows.

When the eccentric drive shaft 12 rotates around the axis _L1 , the sliding block 20 moves in the left-right direction as shown by arrow A and in the vertical direction as shown by arrow B as the eccentric part ₁₃ rotates around the eccentric axis L2. The sliding block 20 and the yoke 15 are allowed to be displaced relative to the yoke 15 only in the direction of the arrow A.
The driving force in the direction of arrow B is transmitted to the yoke 15 due to the relationship between the yoke 15 and the yoke 15, which is supported by the frame due to the fitting relationship between the upper guide shaft 18 and the sliding bearing 9 and the fitting relationship between the lower guide shaft 19 and the sliding bearing 3. Slide 1
4 reciprocates in the vertical direction (in the direction of arrow B), and the material is pressed between the upper die 27 and the lower die 29.

However, with respect to the movement of the sliding block 20 in the direction of arrow A, the link 4 supported by the support shaft 11
A pair of front and rear balance weights 31 connected to the sliding block 20 by links 40 and 42 move in opposite directions with respect to the sliding block 20, and the dynamic balance of the sliding block 20 is maintained. .
The dynamic equilibrium relationship between the sliding block 20 and the pair of balance weights 31 is determined by the piston rod 39.
This can be achieved by unchanging the swinging center position (arm length ratio l ₁ :l ₂ ) of the link 41 corresponding to the inertial mass of the balance weight 31 which swings around the connection point with the link 41 as a fulcrum. can. It should be noted that this dynamic equilibrium relationship is independent of the weight (or mass) of the upper mold 27.

In addition, for the movement of the slide 14 in the direction of arrow B, the piston rod 39 is used to move the slide 14 in the direction of arrow B.
A pair of left and right balance weights 3 connected to 4
1 move up and down in an opposite phase relationship with respect to the slide 14, and the dynamic balance of the slide 14 including the sliding block 20 and the upper die 27 is maintained. This dynamic equilibrium relationship is achieved by supplying and discharging fluid into and out of the cylinder 34 through the ports 36 and 37 to adjust the position of the cylinder 34 with respect to the piston 38 and to determine the position of the ear shaft 35, which is the pivot point of the piston rod 39. You can get it by twisting it. That is, when the weight (or mass) of the upper mold 27 is large, the cylinder 34 is moved toward the slide 14 side, and when the weight (or mass) of the upper mold 27 is small, the cylinder 34 is moved toward the slide 14 side.
All you have to do is move it toward the balance weight 31 side.

The features of this embodiment are as follows.

Since the dynamic balance of the slide 14 and the sliding block 20 is maintained, the occurrence of primary vibration caused by unbalanced inertial force is suppressed, and the bottom dead center of the upper die 27 is maintained regardless of the difference in the weight (or mass) of the upper die 27. The precision is high, the durability of the mold is improved, and product quality can be improved.

Since a balance weight is connected to the slide 14 and the sliding block 20 through direct links to ensure dynamic balance, the impact force on the eccentric portion 13, which is the motion conversion portion of the eccentric drive shaft 12, is reduced. It is possible to improve the life of the machine and pressurizing capacity, and it is also possible to stably perform high-speed operation.

Adjustment of the position of the cylinder 34, that is, adjustment of the dynamic balance with respect to the slide 14, can be performed as appropriate while checking the machining situation and the movement situation of the moving body even while the press 1 is operating. Pressing work can be performed in a quiet state with minimal vibration.

The eccentric part 13 of the eccentric drive shaft 12 is the slide 14
It is located inside the yoke 15, which is a part of the The converting structure) has a simple structure with few components in the drive system, and the distance between the input and output points is small, which together ensure high rigidity of the component parts, resulting in high movement accuracy of the slide 14. can be secured.

In relation to the previous item, a small distance between the input and output points means that the height (length) of the entire drive system, which mainly consists of the eccentric drive shaft 12 and the slide 14, is small.
It is possible to achieve weight reduction, making it suitable for high-speed operation (ensuring high-speed stability).

In the above embodiment, a pair of balance weights 31 were provided on the left and right sides of the slide 14, but the balance weights may be provided only on one side of the slide 14 (in this case, the balance weight becomes large), or the balance weights 31 may be provided on only one side of the slide 14. Three or more balance weights may be provided before and after. Further, two or more upper guide shafts 18 at the upper end of the slide may be provided depending on the size and purpose of the press.

Effects of the Invention As is clear from the above explanation, the present invention has the following effects:
A balance weight for balancing the unbalanced inertia of the slide, which is a reciprocating body, is swingably connected to the slide at one end, and the other end of the piston rod extends in both directions through the cylinder of the fluid pressure cylinder device. The cylinder of the fluid pressure cylinder device is swingably supported by a support rod in an upright position that is swingably supported by the frame, and
Because it can be displaced relative to the piston using fluid pressure, and the balance weight is configured to move up and down in an antiphase relation to the slide, the dynamic balance of the slide, including the upper die, is maintained and unbalanced. The occurrence of primary vibration caused by inertial force is suppressed, and the bottom dead center accuracy can be maintained at a high level regardless of the weight (or mass) of the upper mold, which improves the durability of the mold and improves product quality. It is possible to plan to improve the

In addition, the present invention adopts a structure in which the upper half of the slide is formed as a yoke and the slide is driven by a yoke cam mechanism, so the structure is simple with few components of the drive system, and the structure has high rigidity and the slide In addition to ensuring high movement accuracy, the relative movement of the upper and lower dies is performed accurately, and the drive system including the slide is made smaller and lighter, and the above-mentioned dynamic balance mechanism is adopted. Combined with this, high-speed operation can be performed stably.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a press machine according to an embodiment of the present invention seen from the front, and FIG. 2 is a partial vertical cross-sectional view of the press machine seen from the side (-
Figure 3 shows - in Figure 1.
FIG. 1: Press, 2: Bed, 3: Sliding bearing, 4:
Crown, 5: Column, 6: Side wall, 7: Sliding bearing, 8: Top wall, 9: Sliding bearing, 10: Tie rod, 11: Support shaft, 12: Eccentric drive shaft, 13: Eccentric part, 14: Slide, 15 : Yoke, 16: Upper inner wall surface, 17: Lower inner wall surface, 18: Upper guide shaft,
19: Lower guide shaft, 20: Sliding block, 21:
Central opening, 22: Top surface, 23: Bottom surface, 24: Roller bearing, 25: Roller bearing, 26: Roller bearing, 27:
Upper mold, 28: Bolster, 29: Lower mold, 30: Dynamic balance mechanism, 31: Balance weight, 32:
Support rod, 33: Fluid pressure cylinder device, 34: Cylinder, 35: Ear shaft, 36: Port, 37: Port, 38: Piston, 39: Piston rod, 4
0: link, 41: link, 42: link.

Claims (1)

[Scope of Claims] 1. A slide supporting an upper mold paired with a lower mold disposed on the bed of the frame via a bolster has an upper guide shaft erected at its upper end, and an upper guide shaft erected at its lower end. The slide has at least two lower guide shafts installed vertically, and is supported by a frame via bearings on the upper guide shaft and the lower guide shaft so as to be freely displaceable in the vertical direction, and the upper half of the slide has a yoke. In the yoke, a sliding block having an upper surface and a lower surface parallel to the upper and lower inner wall surfaces of the yoke, both of which are formed as horizontal surfaces, is arranged horizontally relative to each other through upper and lower bearings. An eccentric drive shaft that is displaceably housed, supported by a frame, and extends through the yoke also passes through a circular central opening formed in the sliding block, and the eccentric portion of the eccentric drive shaft is inserted through a bearing. A balance weight rotatably fitted into the central opening and used to balance the unbalanced inertial force of the slide, which is a reciprocating body, is swingably connected to the slide at one end and is connected to the cylinder of the fluid pressure cylinder device. The cylinder of the hydraulic cylinder device is swingably supported by a support rod in an upright position that is swingably supported by the frame. and a press having a dynamic balance mechanism, wherein the balance weight is displaceable relative to the piston by fluid pressure, and the balance weight is configured to move up and down in an opposite phase relationship with respect to the slide. machine. 2. One end of the balance weight is swingably connected to the other end of the piston rod, and the other end of the balance weight is connected to a plurality of links including one link swingably supported by the frame. The balance weight is swingably connected to the sliding block with a link, and the balance weight is configured to move vertically and horizontally in an opposite phase relationship with respect to the slide and the sliding block, respectively. A press machine having a dynamic balancing mechanism according to claim 1.