KR900010481Y1 - Back balancing device of spindle head in machine tools - Google Patents

Abstract

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Description

Back balance retainer of spindle head for machine tool

1 is a schematic explanatory diagram of a conventional back balance holding device.

Figure 2 is a side view showing an embodiment of a back balance maintenance device according to the present invention.

3 is a cross-sectional view of the pulley for guiding the chain of the back balance holding device.

Figure 4 is a schematic diagram illustrating the principle of operation of the present invention.

* Explanation of symbols for main parts of the drawings

1: Spindle Head 2: Flexible Motor

3,4: fixed guide pulley 5: movable pulley

6: fixed support member 7: cylinder

The present invention relates to a back balance holding device of a spindle head for a machine tool. Especially, when the overall height of the machine is large and the stroke of the spindle is set long such as a large machine tool, the spindle head is balanced using a minimum space. The present invention relates to a new back balance maintenance device that can be maintained.

In general, in large machine tools such as machining centers, the vertical distance of the vertical spindles, i.e., the stroke, is large, and the vertical spindles tend to become unstable as the center of rotation gradually descends to process the workpiece. . In this way, when the spindle shakes, not only the machining accuracy of the workpiece is reduced but also excessive force is applied to the bearings, which eventually shortens the life of the spindle. Thus, in the related art, as shown in FIG. 1, a cylinder for maintaining the balance of the spindle is installed on the top of the spindle head to solve the above-mentioned problems. However, the rigid piston rod is directly connected to the spindle head to thereby Since it is a balanced structure, a cylinder with a stroke corresponding to the east and west distance of the spindle should be installed upright on the top of the spindle head. As a result, the cylinder occupies excessive space. There is a problem that you receive. In addition, since the piston rod of the cylinder is directly connected to the spindle head, there is no flexibility in the installation of the cylinder, and even if the alignment between the cylinder and the spindle is incorrect, structurally serious problems occur.

The present invention is conceived in view of the problems of the prior art as described above, the purpose is to minimize the installation space of the cylinder for balance maintenance, the stroke of the cylinder can be shortened to 1/2, An object of the present invention is to provide a back balance maintenance device for a spindle head for a machine tool that can be connected to a spindle head and a cylinder with a flexible member to provide flexibility in a power transmission system.

The object is to provide a spindle head that moves up and down to machine a work piece, a flexible motor that has one end connected to the top of the spindle head, at least two fixed guide pulleys that guide the flexible motor and the flexible motor. A movable pulley suspended by the suspension, a fixed support member supporting the other end of the flexible transmission element above the movable pulley, and a cylinder connected to the center of rotation of the movable pulley and installed in parallel with the spindle head. This can be achieved by the back balance holding device of the spindle head for a machine tool configured to maintain the balance of the spindle head while expanding or contracting by a distance corresponding to one half of the moving distance of the spindle head.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

2 is a schematic side view of the back balance holding device of the spindle head according to the present invention. As is apparent from the figure, the backbalance holding device of the present invention includes a spindle head (1), a flexible motor (2), a pair of fixed guide pulleys (3) (4), a movable pulley (5), It consists of the fixed support member 6 and the cylinder 7.

The spindle head 1 processes the workpiece on the table while lifting and lowering, and a flexible transmission element 2, for example, a chain, is connected to the upper surface via a connecting bolt 1a.

The flexible transmission element 2 is guided by a pair of fixed guide pulleys 3 and 4, the other end of which is fixed to the fixing member 6 of the frame F. The fixed guide pulleys (3) and (4) are rotatably installed on the frame (F) at predetermined intervals, and the movable pulley (5) is provided at the lower portion of the fixed guide pulley (4) to the flexible motor (2). Suspended by

As shown in FIG. 3, the movable pulley 5 is provided with the rotating member 5c assembled on the shaft 5a via the bearing 5b by the rotating material. The piston rod 7a of the cylinder 7 is connected to the movable pulley 5 to maintain the balance of the spindle head while expanding or contracting according to the lifting motion of the spindle head 1.

Next, the operation of the back balance holding device according to the present invention will be described with reference to FIGS. 3 and 4.

In FIG. 3, when the spindle head 1 moves upwards, the flexible transmission element 2 is guided by a pair of guide pulleys 3 and 4 and moved to the right, whereby the movable pulley 5 While descending to the position shown by the dashed-dotted line, the piston 7a of the cylinder 7 contracts. Referring to Fig. 4, the interlocking relationship between the spindle head 1 and the cylinder 7 will be described. When the spindle head moves by the distance X from the point A, it moves by the distance X / 2 from the movable point B. do. As a result, the piston rod of the cylinder connected to the movable pulley will contract or expand by X / 2. Therefore, since the stroke of the cylinder should be set to 1/2 of the spindle head travel distance, the size of the cylinder can be significantly reduced compared to the conventional one.

As described in detail above, according to the back balance holding device of the present invention, since the lifting movement of the spindle head is transmitted to the cylinder by the flexible transmission element, it gives a considerable flexibility to the power transmission system and the operation of the device is smooth. In addition, since the cylinder can be installed parallel to the rear of the spindle head, the installation space of the machine tool can be greatly reduced, and furthermore, the stroke of the cylinder can be reduced by one half of the stroke of the spindle head.

Claims (2)

A spindle head 1 lifting up and down at the head of the machine tool, a flexible transmission element 2 having one end connected to an upper end of the spindle head 1, and at least two guides of the flexible transmission element 2; Fixed guide pulleys (3) and (4), a movable pulley (5) suspended vertically downward by the flexible transmission element, and supporting the other end of the flexible transmission element (2) above the movable pulley. A fixed support member (6) and a cylinder (7) connected to the center of rotation of the movable pulley (5), the cylinder (7) being one half of the lifting movement distance in accordance with the lifting movement of the spindle head (1). Back balance maintenance device for a spindle head for a machine tool configured to shrink or expand a distance corresponding to the balance of the spindle head. 2. The backbalance holding device according to claim 1, wherein the flexible power element (2) is a chain.