JPS5939500A - Balancing device for press - Google Patents

Abstract

PURPOSE:To suppress the vibration of a slide connected to a crank shaft, by providing balancing weights to the eccentric shaft parts of the high speed crank shaft and further providing another balancing weights which rotate at the same speed as the speed of the crank shaft in the direction reverse to the rotating direction of the crank shaft. CONSTITUTION:A crank shaft 12 for applying reciprocating motion to a slide 14 for a press is constituted of spindle parts 12a on both sides and an intermediate spindle shaft 12b, and are provided with a pair of eccentric shaft parts 12c therebetween. A pair of balancing weights 24 are mounted to the part 12b to form the center of gravity offcentered in the direction opposite to the offcentering direction of the part 12c. Sleeves 28 are mounted via bearings 26 in the parts 12a on both sides and another balancing weights 30 are fixed to the same. The effect of eccentric force during revolution of the crank shaft 12 is prevented by such mechanism, whereby the uneven wear of the bearings for the crank shaft is prevented and the generation of the noise resulting from the vibration of the slide 14 mounted by a rod 22 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a balancing device suitable for being assembled into a high-speed crank press to suppress vibrations therein.

In a press in which a slide connected to the crankshaft via a connecting rod is reciprocated by the rotational movement of the crankshaft, the rotation of the crankshaft causes eccentric weight due to the rotation of the crankshaft. The inertial force of the slide 8 and the inertial force accompanying the reciprocating motion of the slide 8 act as an unbalanced force on the crankshaft and the frame supporting the crankshaft.

These unbalanced forces give vibration to the frame and make high-precision press working difficult, so in order to balance the unbalanced forces acting on the frame,
As shown in Japanese Patent No. 7-21190, a first counterweight is provided on the crankshaft and rotates integrally with the crankshaft, and is arranged parallel to the crankshaft and rotatably supported on the frame. It has been proposed to provide a second counterweight on the countershaft and to rotate the second counterweight in a direction opposite to the direction of rotation of the crankshaft at the same speed as the crankshaft.

According to the conventional balancing device, the first balancing weight rotates integrally with the crankshaft, and the second balancing weight is provided on the subshaft and rotates in the opposite direction to the crankshaft. Since the unbalanced force caused by the rotation of the crankshaft is balanced, strong vibrations can be prevented from acting on the frame.

However, in the conventional balancing device, the second balancing weight is attached to a subshaft arranged parallel to the crankshaft, so In order to secure a large space, the entire press becomes larger. Furthermore, since it is impossible to prevent an unbalanced force from acting on the crankshaft itself due to the rotation of the crankshaft, this unbalanced force acts as a strong eccentric force on the bearing for supporting the crankshaft on the frame. As a result, the bearings may wear unevenly, reducing the durability of the bearings and causing the crankshaft to vibrate during rotation of the crankshaft. The above-mentioned vibration of the crankshaft causes a decrease in the accuracy of the press operation.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a balance device for a press that does not increase the size of the press and does not generate vibrations in its crankshaft.

In order to balance the inertial force of the eccentric weight accompanying the rotation of the crankshaft and the inertial force accompanying the reciprocating movement of the slide 9 connected to the crankshaft, the present invention provides an eccentric shaft portion of the crankshaft. a first balance weight provided integrally therewith, and a second balance weight rotated in a direction opposite to the rotational direction of the crankshaft at the same speed as the crankshaft; It is characterized in that a balance weight is supported on the main shaft portion of the crankshaft.

According to the present invention, the first balanced weight is provided on the eccentric shaft portion of the crankshaft, and the second balanced weight is supported on the main shaft portion of the crankshaft. In the crankshaft, the inertial force of the eccentric weight associated with the rotation of the crankshaft and the inertial force associated with the reciprocating movement of the slide are balanced. Therefore, the unbalance caused by the rotation of the crankshaft does not act on the crankshaft itself, and the strong eccentric force as in the conventional case does not act on the bearings that support the crankshaft on the frame.

The features of the invention will become clearer from the following description of the illustrated embodiments.

As shown in FIG. 1, the press 10 according to the present invention includes a crankshaft 12 and a press slide 514 that reciprocates by rotation of the crankshaft.

The shaft 12 is rotatably supported by a frame 18 via bearings 16 at both side main shaft parts 12a and an intermediate main shaft part 12b, which are rotational axes, and is driven around the central axis of the main shaft parts 12a + 12b. be rotated. Intermediate main shaft portion 12b and each side main shaft portion 12. a
A pair of eccentric shaft portions 1 are eccentric in the same direction from the rotation center axis of the main shaft portions 12a and 12b.
2c is provided. Each eccentric shaft portion 12. A connecting rod 22 is attached to c via a bearing 20 surrounding the eccentric shaft portion, and the slide 14 is connected to the tip of the connecting rod 8.

Therefore, as is well known in the art, the shaft 1
The slide 14 reciprocates by 20 rotations.

A pair of first balance weights 24 are fixedly provided on the intermediate shaft portion 12b. The first balanced weight 24 has a center of gravity at a position eccentric in a direction opposite to the eccentric direction of the eccentric shaft portion 12c.

A sleeve 28 is provided on each side main shaft portion 12a via a bearing 26 surrounding the main shaft portion. A second balance weight 60 is fixedly provided on each sleeve 28, and thereby each second balance weight 60 is rotatably supported around the main shaft portion 12a. Each balance weight 6o has a center of gravity at a position offset in the radial direction from its rotation axis.

A toothed portion 28a is provided at one end of each sleeve 28, and the toothed portion meshes with a gear 62. Each gear roller 2 has a respective driven shaft 3 supported on the frame 18 via a bearing 64.
It is fixed to one end of 6.

A timing pulley 68 is fixed to the other end of each driven shaft, and a timing pulley 40 corresponding to the pulley 68 is fixed to each main shaft portion 1'2a. A timing belt 42 passes around the pulleys 38, 40 to transmit the shaft 120 rotations to the driven shaft 36. Thereby, each second counterweight 60 is configured such that when the slide is, for example, at its bottom dead center, the center of gravity of the second counterweight 60 is at the first point, as shown in FIG. in a direction opposite to the rotating direction of the shaft 12 so as to coincide with the eccentric direction of the center of gravity of the balanced weight 24;
rotates at the same speed as.

Double-balanced weight 24 according to the present invention. Before explaining the balance conditions of 0 with reference to FIGS. 2 and 6, the meaning of each symbol will be explained below.

Vehicle weight of M Nisrite'''14 ml: First balance weight 240 Weight 1: Vehicle length of second balance weight O m3: Eccentric weight of crankshaft 12 R1: Eccentric shaft portion 12 of crankshaft 12 Eccentric weight pjK R2: Distance from the rotation axis of the crankshaft 12 to the center of gravity of the first balance weight 24 R3: Distance from the rotation axis of the crankshaft 120 to the center of gravity of the second balance weight 60 Now, the connecting rod 22 If we ignore the consecutive ratio of
The horizontal balance condition in the positional relationship shown in Figure 2 is (M+m3)xR,= , m, xR, 10m2xR3-
The balance condition of the vertical force direction in the positional relationship given by ・-・(]) and shown in Fig. 6 is m3×R□+m2×R3=m□×R2...
) is given by

Therefore, as in the case of the conventional balancing device, m that satisfies equations (1) and (2) for both balanced weights 24 and 30.
By selecting 1rl12p RI R2, the inertial force of the eccentric weight and the slide 14 due to the rotation of the crankshaft 12 are reduced.
It is possible to balance the inertial force associated with the reciprocating motion of the

Moreover, in the press 10 according to the present invention, the second balance weight 60 for balancing the internal force in cooperation with the first balance weight 24 is supported on the main shaft portion 12a of the shaft 12. and rotates around the main shaft.

Therefore, since the inertial force of the eccentric weight accompanying the rotation of the shaft 12 and the inertial force accompanying the reciprocating movement of the slide 14 are balanced in the shaft 12, the internal force is substantially It does not act on the shaft 12. As a result, the shaft 12 is connected to the frame 18.
A strong eccentric force unlike the conventional one is not applied to the bearing 16 supported by the bearing 16, and uneven wear of the bearing can be prevented, and rotational movement of the crankshaft due to uneven wear of the bearing 16 can be prevented. I can do it.

Furthermore, since the press 10 does not require a spacer associated with the countershaft for attaching the second balanced weight, the height of the press 10 can be reduced compared to the conventional one. , thereby making it possible to reduce the overall size of the press.

According to the present invention, as described above, since eccentric force can be prevented from acting on the crankshaft, uneven wear of the bearings that support the crankshaft on the frame can be prevented. Therefore, it is possible to prevent rotational vibration of the crankshaft due to uneven wear of the bearing, eliminate noise caused by rotational vibration of the crankshaft, and reduce the overall vibration of the press, which allows the press to operate at high speed. The accuracy of work can be improved.

Further, the press can be dynamically balanced without increasing the size of the press, and durability can be improved by preventing uneven wear of the bearing.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of a press according to the present invention, and FIGS. 2 and 6 are schematic diagrams for explaining the equilibrium relationship of the press according to the present invention. 12: Crankshaft, 12a, 12b: Main shaft portion, 12o: Eccentric shaft portion, 14 Ni Ride, 2
2: Connecting means, 24: First balance weight, 28 Ni sleeve, 28a: Teeth, filter O: Second balance weight,
ro 2: gear, 66: driven shaft. Agent Patent Attorney Nobuyuki Matsunaga

Claims (1)

[Scope of Claims] (1,) A slide having a main shaft portion and an eccentric shaft portion and connected to the eccentric shaft portion via a connecting means is driven and rotated around the main shaft portion in order to reciprocate the slide. A balancing device for a press having a shaft, the first balancing weight being provided integrally with the main shaft portion and having a center of gravity at a position eccentric in a direction opposite to the eccentric direction of the eccentric shaft portion. is rotatably fitted to the main shaft, has a center of gravity at a position eccentric in the radial direction from the central axis of the main shaft, and when the slide is at the dead center position, the center of gravity is at the first position. a second counterweight that is rotated at the same speed as the crankshaft in a direction opposite to the direction of rotation of the crankshaft to be located in the same direction as the center of gravity of the counterweight; Device. (2) The second balance weight is fixedly attached to a sleeve supported on the main shaft through a ring, and the sleeve is parallel to the main shaft with teeth provided at its end. The balancing device according to claim 1, which meshes with a gear fixed to a driven shaft which is disposed in the main shaft portion and driven by the main shaft portion.