JPH08118084A - Press machine - Google Patents

Abstract

PURPOSE: To improve the machining precision by respectively connecting a crank shaft and a ram with both end parts of the ram and the intermediate, and reducing the deformation of the ram without increasing the weight of the ram even against the un-uniform load. CONSTITUTION: In a press machine 2 to press with a lower die attached on the upper face of a bolster 8 and an upper die attached on a ram 16, a crank shaft 14 is supported freely rotating to the upper side crank of the frame 4. This crank shaft 14 and the ram 16 are connected with a 1st to 3rd connecting rods 18, 20, 22 attached relatively free rotating on the crank shaft 14 through ball joints 24, 32, 40 and plunger 26, 34, 42. In this situation, the 1st and the 2nd connecting rods 18, 20 are connected to the both end parts of the ram 16 respectively, and the 3rd connecting rod 22 is connected to the intermediate part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press machine, and more particularly to a press machine having a crankshaft, a ram, and a connecting rod connecting them.

[0002]

2. Description of the Related Art A conventional press machine to which the present invention is related has a frame constituting a main body of the press machine. A bed is provided in the middle of the frame, and a bolster is attached to the upper surface of the bed. A crown is provided above the frame. A crankshaft is rotatably supported on the crown. A ram (slide) is movably supported at a position below the crankshaft of the frame. That is, a cylindrical portion is provided at each end of the ram, and a support shaft is provided at a corresponding portion of the frame so as to extend in the vertical direction. By fitting the cylindrical portion to the support shaft via the bearing, the ram can be vertically moved while being guided by the support shaft. The crankshaft and ram are the first
Connected by a connecting rod and a second connecting rod. One end of the first connecting rod and one end of the second connecting rod are connected to the crankshaft so as to be rotatable relative to each other with a gap in the axial direction. The other end of the first connecting rod and the other end of the second connecting rod are connected to both ends of the ram. The other end of each of the first and second connecting rods and the ram are connected via a king pin or a ball joint.

[0003]

In the above conventional press machine, the crankshaft and the ram are connected by the first connecting rod and the second connecting rod. The distance between the first connecting rod and the second connecting rod (horizontal distance between the center lines) is L, and the amount of deformation of the ram deflected in the vertical direction at the central portion in the longitudinal direction by the load acting on the ram during processing is l. Then l and L
The following relational expression holds between and. l∝L ³ ── (1) It is necessary to reduce the deformation 1 of the ram as much as possible. As is clear from the above formula (1), if the distance L between the first and second connecting rods is reduced, the deformation amount 1 of the ram can be reduced. However, the horizontal distance between the first connecting rod and one end of the ram and the horizontal distance between the second connecting rod and the other end of the ram are large. Since these portions form, so to speak, overhang portions, when a load is applied to the portions, both ends are more likely to be deformed in a warped form. Therefore, if L is made small, the ability to cope with uneven load (eccentric load) will be reduced.

When the distance L between the connecting rods is increased, the deformation amount 1 of the ram is remarkably increased, as is apparent from the equation (1). That is, in this case, the load acting on the central portion of the ram is received by the bending rigidity of the ram. Therefore, the distance L
In order to reduce the deformation amount 1 of the ram in the state of increasing, it is necessary to increase the second moment of inertia of the cross section of the ram. As a result, the weight of the ram increases, which causes deterioration of the motor function (processing speed is reduced), and causes problems such as increased vibration and reduced durability.

In recent years, as a die of a press machine, a die for performing multi-step continuous processing such as a progressive die or a transfer die has been widely adopted. Molds of this type require relatively long span rams. Uneven loads distributed over a wide range will be applied to the ram. Thus, even in continuous machining in which the load on the ram is imbalanced, the required machining accuracy must be reliably maintained. However, in the conventional press machine, since the ram span is relatively long, it is not possible to reduce the deformation without increasing the weight thereof,
It has not yet met the requirements mentioned above.

An object of the present invention is to provide an improved press machine capable of reducing the deformation of the ram and increasing the working accuracy without increasing the weight of the ram even when the load is uneven. .

[0007]

According to the present invention, a crown provided above a frame, a crankshaft rotatably supported by the crown, a ram on which an upper die is mounted, and a crankshaft And a first connecting rod and a second connecting rod that connect the ram and the ram, wherein one end of the first connecting rod and one end of the second connecting rod are axially spaced from the crankshaft. In the press machine, the other end of the first connecting rod and the other end of the second connecting rod are connected to both ends of the ram. A third connecting rod is connected to the ram, wherein one end of the third connecting rod has the one end of the first connecting rod and the second connecting rod of the second connecting rod. Is relatively rotatably coupled to the crankshaft between the end and the other end of the third connecting rod, the other end of the first connecting rod and the other end of the second connecting rod. Between
A press machine characterized in that it is connected to the ram.

[0008]

The press machine of the present invention is provided with a third connecting rod in addition to the first connecting rod and the second connecting rod for connecting the crankshaft and the ram. The third connecting rod is arranged between the first connecting rod and the second connecting rod. The third connecting rod is the first
Is set to a center position between the connecting rod and the second connecting rod or a position deviated from the center position. Since this position changes the position where the load is applied depending on the form of press working, it is appropriately set in accordance with this change. As described above, in the present invention, in the ram having a relatively long span, the first connecting rod and the second connecting rod are used.
Even if the distance L between the connecting rods of is set large,
Since the third connecting rod is arranged between them,
The force (pressurizing force) that pushes the ram (that is, the upper mold) is averaged, and the ability to deal with the uneven load is significantly improved. As a result, the deformation of the ram can be reduced and the machining accuracy can be improved without increasing the weight of the ram even with respect to the uneven load.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a press machine improved according to the present invention will be described below with reference to FIG. The press machine, generally designated by the reference numeral 2, has a frame 4 forming its body. A bed 6 is provided at an intermediate portion of the frame 4, and a bolster 8 is mounted on the upper surface of the bed 6.
A lower die (not shown) is detachably attached to the upper surface of the bolster 8. Four columns (posts) 1 at the four corners of the frame 4
0 (only two are shown in the figure) are integrally provided. A crown 12 is integrally formed above the column 10. A crank shaft 14 is rotatably supported on the crown 12. Above the bolster 8, rams 16 to which upper molds are attached are arranged with a space between them.
It is connected to the crankshaft 14 via a first connecting rod 18, a second connecting rod 20 and a third connecting rod 22. One end of the first connecting rod 18 and one end of the second connecting rod 20 are connected to the crankshaft 14 so as to be rotatable relative to each other with a space therebetween in the axial direction, and the other end of the first connecting rod 18 and the second connecting rod 18 are connected to each other. The other end of the connecting rod 20 of the ram 16
Are connected to both ends. One end of the third connecting rod 22 is rotatably connected to the crankshaft 14 between the one end of the first connecting rod 18 and the one end of the second connecting rod 20, and the third connecting rod 22. The other end of 22 is connected to the ram 16 between the other end of the first connecting rod 18 and the other end of the second connecting rod 20.

More specifically, one end (upper end) of the first connecting rod 18 is rotatably connected to the left end of the crankshaft 14, and the other end (lower end) thereof is connected to the plunger 26 via the ball joint 24. Is connected to one end (upper end) of. The other end (lower end) of the plunger 26 is fixed to the left end of the ram 16. The plunger 26 is a cylindrical portion 28 provided at the left end of the bottom of the crown 12.
It is vertically movably fitted to the bearing via a bearing 30. Second
One end (upper end) of the connecting rod 20 of is connected to the right end portion of the crankshaft 14 so as to be relatively rotatable, and the other end (lower end) thereof.
Is connected to one end (upper end) of a plunger 34 via a ball joint 32. The other end (lower end) of the plunger 34 is fixed to the right end of the ram 16. The plunger 34 is vertically movably fitted to a cylindrical portion 36 provided at the right end portion of the bottom portion of the crown 12 via a bearing 38. One end (upper end) of the third connecting rod 22 is relatively rotatably connected to the middle part of the crankshaft 14, and the other end (lower end) is connected to one end (upper end) of the plunger 42 via the ball joint 40. . Plunger 42
The other end (lower end) of is fixed to the intermediate portion of the ram 16.
The plunger 42 is vertically movably fitted via a bearing 46 to a cylindrical portion 44 provided in the middle portion of the bottom of the crown 12. When the crankshaft 14 is rotated by a drive motor (not shown), the ram 16 follows the vertical movement of each plunger 26, 34 and 42 actuated by the first, second and third connecting rods 18, 20 and 22. It can be moved back and forth. The reciprocating movement of the ram 16 is performed intermittently at a predetermined timing.
Predetermined press working is performed between the upper die (not shown) attached to the upper die and the upper die attached to the bolster 8.

The third connecting rod 22 includes a first connecting rod 18 and a second connecting rod 2.
It is set to a center position between 0 and 0 or a position deviated from the center position. Since this position changes the position where the load is applied depending on the form of press working, it is appropriately set in accordance with this change. For example, when the press machine 2 is a transfer press, a plurality of upper molds and lower molds are provided in the ram 16 respectively.
And the longitudinal direction of the bolster 8 (the left-right direction in FIG.
It is installed along the material feeding direction). Therefore, the span of the ram 16 becomes relatively long, and the action mode of the load acting on the ram 16 differs depending on the number, type, and arrangement of the upper and lower dies. Even in such a case, in the present invention, the first connecting rod 18 and the second connecting rod 18
Even if the distance L between the connecting rods 20 is set to a large value, the third connecting rod 22 is arranged between them, so that the force (pressing force) for pressing the ram 16, that is, the upper mold is averaged, and the uneven load is applied. The ability to cope with is significantly improved. As a result, the deformation of the ram 16 can be reduced without increasing the weight of the ram 16 even with an uneven load, and the processing accuracy can be improved. Since the weight of the ram is reduced, the moving function is improved (the processing speed is increased), and there are advantages such as reduction of vibration and improvement of durability.

Although one embodiment of the press machine according to the present invention has been described above, the present invention is not limited to the above-mentioned embodiment, and various modifications or modifications can be made without departing from the scope of the present invention. is there. For example, in the embodiment, the first, second and third connecting rods 18,
20 and 22 are ball joints 24 and 3, respectively.
It is connected via 2 and 40 to the fixed plungers 26, 34 and 42 of the ram 16. However,
The connection structure of the ram 16 and the first, second and third connecting rods 18, 20 and 22 is not limited to the embodiment. For example, a cylindrical portion is provided at each end of the ram 16, and a support shaft is provided at a corresponding portion of the frame so as to extend in the vertical direction. By fitting the cylindrical portion to the support shaft via a bearing, When the ram is configured to be vertically moved by being guided by the support shaft, the other end of each of the first, second and third connecting rods 18, 20 and 22 and the ram 16 are connected to the plungers 26, 34. And 42 (without the plungers 26, 34 and 42) and via a king pin or ball joint.

[0013]

According to the press machine constructed in accordance with the present invention, the deformation of the ram can be reduced and the machining accuracy can be improved even if the load is uneven, without increasing the weight of the ram.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a press machine improved according to the present invention.

[Explanation of symbols]

 2 Press machine 4 Frame 8 Bolster 14 Crankshaft 16 Ram 18 First connecting rod 20 Second connecting rod 22 Third connecting rod 24 Ball joint 26 Plunger 32 Ball joint 34 Plunger 40 Ball joint 42 Plunger

Claims (1)

[Claims] 1. A crown provided above a frame, and a crank shaft rotatably supported by the crown,
A ram to which the upper die is mounted, a first connecting rod and a second connecting rod that connect the crankshaft and the ram are provided, and one end of the first connecting rod and the second connecting rod are provided. One end is rotatably connected to the crankshaft at a distance in the axial direction,
In the press machine, the other end of the first connecting rod and the other end of the second connecting rod are connected to both ends of the ram. In a press machine, a third connectin connecting the crankshaft and the ram. A third rod, one end of the third connecting rod is
The crankshaft is relatively rotatably coupled between the one end of the first connecting rod and the one end of the second connecting rod, and the other end of the third connecting rod is connected to the first connecting rod. A press machine characterized in that it is connected to the ram between the other end of the connecting rod and the other end of the second connecting rod.