JPH0411318B2 - - 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, it relates to a press machine that uses a yoke cam as a slide drive mechanism.

Prior Art and Problems to be Solved by the Invention In a press machine, it is required that the relative movement between an upper die (including a punch) and a lower die attached to a slide and a bolster be performed accurately. If the relative motion between the upper and lower molds is not accurate, not only will the mold life be shortened, but the product accuracy will also be impaired. Therefore,
Press machines are required to have a certain level of static accuracy (at no load) and dynamic accuracy (at processing load). Static accuracy includes the parallelism between the lower surface of the slide and the upper surface of the bolster, the perpendicularity between the vertical movement of the slide and the upper surface of the bolster, and the amount of clearance between the slide and gib.Dynamic accuracy includes the horizontalness of the slide. Examples include "shaking" in the direction, thermal influence on the bottom dead center position of the slide (due to thermal deformation of each member), etc. In this way, there are many conditions required for slides.
It is no exaggeration to say that the accuracy of a press machine is determined by the quality of the slide.

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 member. However, ensuring rigidity and reducing weight are contradictory requirements, and mechanical designers struggle to find a compromise between them.

However, in a crank press that transmits the rotation of the crankshaft to the slide via a connecting rod, and the slide reciprocates along a guide member of the frame, the length of the connecting rod must be adjusted to ensure a predetermined slide stroke. The drive system that converts rotational motion into reciprocating motion using two rotating pairs and joints is complex, making it difficult to ensure the rigidity of the drive system, the weight of moving parts is large, and high-speed operation. It has disadvantages such as being disadvantageous when carrying out.

The present invention was created against this technical background, and is a press machine that simplifies the structure of the drive system, secures the rigidity of the drive system, and reduces the weight of the moving members that make up the drive system. The purpose is to improve the accuracy of

Means for Solving the Problem and Its Effect This object is to provide a slide that supports an upper mold with an upper guide shaft vertically installed at its upper end and at least two lower guide shafts vertically installed at its lower end. The slide is supported by a frame via bearings at the upper guide shaft and the lower guide shaft so as to be freely displaceable in the vertical direction, and the slide has a hollow part inside which is formed a space for accommodating the sliding block. The hollow part has an upper inner wall surface and a lower inner wall surface that are formed as horizontal surfaces, and the sliding block has an upper surface and a lower surface that are parallel to the upper inner wall surface and the lower inner wall surface. , a sliding block is housed in the hollow portion so as to be relatively displaceable in a first horizontal direction via upper and lower bearings, and is supported by a frame in a second horizontal direction perpendicular to the first horizontal direction. An eccentric portion of an eccentric drive shaft extending through the hollow portion is rotatably fitted into a central opening formed in the sliding block via a bearing, and the eccentric portion of the eccentric drive shaft extends through the hollow portion, and is rotatably fitted into a central opening formed in the sliding block. To provide a press machine (hereinafter simply referred to as a press) having a structure in which there is no relative vertical movement between the eccentric parts of the drive shaft, and a slide is reciprocated in the vertical direction via a sliding block by rotation of the eccentric drive shaft. This is achieved by doing.

It can be said that the eccentric portion of the eccentric drive shaft, the sliding block, and the slide constitute a yoke cam mechanism, and the slide serves as the yoke of the yoke cam mechanism. When the eccentric drive shaft rotates, the slide reciprocates vertically through a yoke, ie, a sliding block that is only allowed to move laterally relative to the slide. 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.

Example The illustrated embodiment will be described below.

FIG. 1 is a longitudinal sectional view of the press 1 seen from the side, and FIG. 2 is a longitudinal sectional view of the press 1 seen from the front. The frame of the press 1 is composed of a bed 2, which is a lower member, and an upper member, in which a column 4 is integrated with a crown 6. Both upper and lower members are integrated with a plurality of tie rods 8. Connected by screws. Cylindrical slide bearings 5, 5 are fitted into the through holes formed in the left and right columns 4 when viewed from the front, and an eccentric having an eccentric portion 10 with a circular cross section passes through the slide bearings 5, 5. A drive shaft 9 is supported. In the figure, L ₁ indicates the center axis of rotation of the eccentric drive shaft, and L ₂ indicates the center axis of the eccentric portion 10 . This eccentric drive shaft 9 is driven and rotated by a motor via a known power transmission mechanism (not shown).

The slide 12 is disposed within the central space 11 of the frame, and has an upper guide shaft 16 erected at its upper end.
A cylindrical sliding bearing 7 is attached to the crown 6.
At least two lower guide shafts 18, which are fitted in the lateral protrusion 17 at the lower end and are vertically provided, are fitted into cylindrical sliding bearings 3 attached to the bed 2.
The axes of the upper and lower guide shafts 16 and 18 are both parallel to the vertical line, and the slide 12 reciprocates in the vertical direction ( vertical movement).

Further, the slide 12 is provided with a hollow section 13, and an upper inner wall surface 14 and a lower inner wall surface 15 of the hollow section are both horizontal planes intersecting a vertical line at right angles. A sliding block 19 having a generally rectangular cylinder shape is housed in the hollow portion 13, and the eccentric drive shaft 9 extends through the sliding block 19 and the hollow portion 13. Both the upper surface 21 and the lower surface 22 of the sliding block 19 are the upper inner wall surface 14 of the hollow part 13,
It is a horizontal plane parallel to the lower inner wall surface 15, and the plane 21,
Caged roller bearings 23 and 24 are interposed between surfaces 22 and 15, respectively.
3 and 24, the sliding block 19 is connected to the hollow part 1.
3 in the first horizontal direction, that is, the front-back direction (arrow A
(see). The eccentric drive shaft 9 extends in a second horizontal direction perpendicular to the first horizontal direction (that is, a direction perpendicular to the paper plane of FIG. 1).

The sliding block 19 has a circular central opening 20 in which a caged roller bearing 2 is inserted.
An eccentric portion 10 of an eccentric drive shaft 9 is fitted through the eccentric drive shaft 5 . Between the sliding block 19 and the hollow part 13 in which the roller bearings 23 and 24 are interposed, and the roller bearing 2
There is no room for relative displacement in the vertical direction between the sliding block 19 and the eccentric portion 10, in which the sliding block 5 is interposed, and both are assembled in a tightly fitted state.

The slide 12, which is reciprocated in the vertical direction by the rotation of the eccentric drive shaft 9, carries an upper mold 26 at its lower end, and connects the lower mold 28 and the upper mold 26, which are fixed to a bolster 27 on the bed 2. Pressing is performed through cooperative action.

When operating the press 1 having such a structure,
When the eccentric drive shaft 9 rotates around the axis _L1 ,
As the eccentric part 10 rotates about the eccentric axis _L2 , the sliding block 19 is moved in the front-back direction shown by arrow A and the vertical direction shown by arrow B, and is moved in the direction of arrow A with respect to the hollow part 13. Due to the relationship between the sliding block 19 and the hollow portion 13, which are allowed to be relatively displaced only by The slide 12 supported by the frame through the fitting relationship between the lower guide shaft 18 and the slide bearing 3 reciprocates in the vertical direction (in the direction of arrow B), and presses the material between the upper die 26 and the lower die 28. will be held.

The features of this embodiment are as follows.

The perpendicularity between the vertical movement (reciprocating movement) of the slide and the top surface of the bolster, that is, the accuracy of the movement of the slide, is determined by the ratio of the guide length (vertical length) and width of the slide, and the amount of clearance between the guide parts. , in the case of press 1, the slide 12 is
Upper guide shaft 1 protruding from its upper and lower ends
6. Since the lower guide shaft 18 is guided by the frame, the ratio of the interval length (guide length) between the upper and lower guide shafts 16, 18 to the interval length (width length) of the lower guide shafts 18, 18 is sufficient. It is large and can ensure high movement accuracy of the slide 12.

For the reason stated in the previous section, the relative movement between the upper mold 26 attached to the lower surface of the slide and the lower mold 28 set on the bolster 27 is performed with high precision.
High product processing accuracy can be obtained.

The lower guide shaft 18 is at the same height as the machining surface, and even if each component is deformed due to work load or heat generated during machining, the upper mold 26 and lower mold 2
Changes in the relative positional relationship of 8 are minimized.

An eccentric portion 10 of the eccentric drive shaft 9 is located inside a hollow portion 13 that is a part of the slide 12, and the driving force due to the eccentric rotation of the eccentric portion 10 is applied to the sliding block 1.
9 to the slide 12 (a structure in which rotary motion is converted into reciprocating motion by a rotating pair and a sliding pair), the structure is simple with few components of the drive system, and the distance between the input and output points is small. Combined with the small value of , it is possible to ensure high rigidity of the constituent members, and it is possible to ensure high movement accuracy of the slide 12.

Related to the previous item, the small distance between the input and output points means that the eccentric drive shaft 9 and the slide 1
This means that the length of the column 4 can be reduced by sufficiently reducing the height (length) of the entire drive system mainly composed of the column 4, and it is possible to improve the rigidity of the frame.

In relation to the previous item, the weight of the slide 12, which is a moving member, can be reduced, making it suitable for high-speed movement (ensuring high-speed stability).

In the above embodiment, only one upper guide shaft 16 was provided at the upper end of the slide, but two or more may be provided depending on the size and purpose of the press. In addition, a lower guide shaft 1 is installed vertically on the lower end protrusion 17 of the slide 12.
At least two 8 are provided depending on the size, purpose, workability, etc. of the press, as shown in FIGS. 3 to 5.

Effects of the Invention As is clear from the above description, since the present invention adopts a structure in which the slide is driven by a yoke cam mechanism, the structure is simple with few components of the drive system, and the rigidity of the component members is high and the slide is Movement accuracy is ensured, the relative movement of the upper mold and lower mold is performed accurately, and the drive system including the slide is made smaller and lighter, allowing high-speed operation.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a press machine according to an embodiment of the present invention as seen from the side, and FIG. ), and FIGS. 3 to 5 are views (views taken along line DD in FIG. 2) showing the arrangement of the lower guide shaft provided at the lower end of the slide of the press machine, respectively. DESCRIPTION OF SYMBOLS 1...Press, 2...Bed, 3...Slide bearing, 7...Slide bearing, 9...Eccentric drive shaft, 10...
...Eccentric part, 12...Slide, 13...Hollow part,
14... Upper inner wall surface, 15... Lower inner wall surface, 16
... Upper guide shaft, 18 ... Lower guide shaft, 19 ...
Sliding block, 20... circular central opening, 21...
Upper surface, 22... Lower surface, 23, 24, 25... Roller bearing, 26... Upper die, 27... Bolster, 28...
...lower mold.

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 at its lower end. The slide has at least two vertically installed lower guide shafts, and is supported by a frame via bearings at the upper guide shaft and the lower guide shaft so as to be freely displaceable in the vertical direction, and the slide accommodates a sliding block. The sliding block has a hollow part with a space formed therein, and the hollow part has an upper inner wall surface and a lower inner wall surface that are formed as horizontal surfaces, and the sliding block has a hollow part formed on the upper inner wall surface and the lower inner wall surface. A sliding block is housed in the hollow portion so as to be relatively displaceable in a first horizontal direction via upper and lower bearings, and is supported by a frame and has an upper surface and a lower surface parallel to each other. The eccentric part of the eccentric drive shaft, which extends through the hollow part in a second horizontal direction perpendicular to the horizontal direction of the block, is rotatably fitted into the central opening formed in the sliding block via a bearing. There is no relative vertical movement between the hollow part, the sliding block, and the eccentric part of the eccentric drive shaft, and the slide is reciprocated in the vertical direction via the sliding block by rotation of the eccentric drive shaft. A press machine configured with.