JPH0325844Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a boring bar with a vibration isolator. [Prior Art] Generally, when performing precision hole drilling using a jig boring bar, if the shaft length of the boring bar is long, vibrations called "chattering" occur, which hinders precision hole drilling. Therefore, in order to prevent the vibration from occurring, a partition has been installed inside the boring bar to store sand, etc., or a weight has been attached to the boring bar so that it resonates with the boring bar. [Problem to be solved by the invention] However, in the above-mentioned conventional technology, it is difficult to find the appropriate position to attach the weight to the boring bar to cause resonance, and it is difficult to adjust the attachment position. It was difficult because it required an experiential element, and ultimately led to poor workability. This invention was proposed as an improvement plan in view of the above circumstances, and it is possible to easily place anti-vibration weights in the appropriate position on a boring bar with a simple device.
Furthermore, it is an object of the present invention to provide a boring bar with an anti-vibration device that has good workability. [Means for Solving the Problems] In order to solve the above problems, the present invention provides a boring bar in which a taper shank is formed at one end of the main body and a tool is provided at the other end. a cylindrical hollow part formed along the center; a center shaft rotatably supported on the boring bar axis within the cylindrical hollow part; and a center shaft that is inserted and engaged with one end to move on the center shaft. a cylindrical screw formed with a cylindrical screw, a weight having an engaging portion whose one end engages with the cylindrical screw in a rotatable manner and movably fitted onto the center shaft; a gear rotatably supported within the bar body; a rotation ring rotatably inserted into the outer periphery of the boring bar body and having a gear formed on the inside and a locking portion on the outside; An internal gear of the ring, an intermediate gear meshing with the gear and rotatably supported by the boring bar body, and an intermediate gear provided on the stationary side that moves back and forth in the axial direction of the boring bar to engage with a locking portion of the rotary ring. It is constructed with a movable rotation stopper. [Function] The position adjustment function of the anti-vibration weight will be explained based on the configuration of the present invention. In a boring bar inserted into the main shaft inside the housing, the rotating ring is locked by advancing the rotation stopper provided on the fixed side (housing) to the outer locking part of the rotating ring provided on the outer periphery of the boring bar. let Next, when the main shaft in the housing is rotated, the boring bar is interlocked, and the cylindrical screw is centered by the interlocking rotation of the gear supported in the boring bar, the intermediate gear, and the internal gear of the rotary ring that meshes with the intermediate gear. Move around the axis. The movement of the center shaft is caused by the movement of a weight connected to the center shaft via an engagement member, and the rotation of the boring bar continues until it reaches a position that is assumed to be an appropriate position. After that, the rotation of the boring bar is stopped, the locking of the rotation stopper is released, the rotation of the boring bar is started, and the vibration is examined. The above-mentioned operation is repeated until the weight is installed at the proper position, and when the weight is at the proper position, it is fixed and the regular hole machining is performed. [Example] Hereinafter, an example of the present invention will be described in more detail based on the drawings. FIG. 1 shows a partially sectional side view of a first embodiment of a boring bar with a vibration isolator according to the present invention. In FIG. 1, a boring bar 1 has a tapered shank portion 1a formed at one end to be inserted into a fixed side (housing) inner spindle head 3, and a part of the boring bar 1 has a tool gripping portion 1a.
b is formed and the tool is replaced by ATC. A hollow portion 4 is formed inside the boring bar 1 to accommodate center shafts 10, 11, a weight 12, etc. forming a vibration isolator. A cover 5 is screwed onto the other end of the boring bar 1. Various chips 6 are attached to the tip of this cover 5.
A tool 7 incorporating a tool 7 is attached, and a cover 5 partially fitted into the hollow part 4 of the boring bar 1 is attached.
A center hole 5a is formed on the axis of the boring bar to support a steel ball 8. On the axis of the boring bar in the hollow part 4, there are two center shafts 10 supported by a steel ball 8 engaged with the center hole 5a of the cover 5 and a steel ball 9 housed in the hollow part 4. 11 are provided. The center axis 1
0 is threaded over its entire length, and thread 11 is partially threaded. A weight 12 made to have a slightly smaller diameter than the hollow part 4 of the boring bar 1 is loosely inserted into the outer diameter of the center shaft 10 so as to be movable on the center shaft 10, and the front and rear nuts 13, 14,
15. The two center shafts 10 and 11 are connected by nuts 14 and 15 that are screwed into threaded portions.
The length can be adjusted by tightening or loosening 3, 14, and 15. A similar center hole 10a is cut into one end of the center shaft 10 in order to support the steel ball 8 between it and a center hole 5a cut in the plane of the cover 5 which is partially fitted into the hollow part 4 of the boring bar. It has been set up. A similar center hole 11a is also formed at one end of another center shaft 11 in order to support the steel ball 9 between it and the end of the hollow portion 4 of the boring bar. Next, the operation of the first embodiment configured as described above will be explained. Set the clearance between the steel balls 9 in the hollow part 4 of the boring bar 1 and the steel balls 8 on the cover 5 side to 0, and tighten the nuts 13, 14, 15 so that the preload becomes 0.
Adjust by moving the center shafts 10 and 11 back and forth. This time, after setting the weight 12 in advance at an appropriate position that is thought to be the resonance point and fixing it with nuts 13, 14, and 15, for example, place the boring bar 1, with its taper shank portion 1a facing down, with the steel balls 8, 9, and the center shafts 10, 1.
The first grade is stored in the hollow part 4 of the boring bar 1. After the cover 5 is set, the boring bar 1 is inserted into the spindle head 3 and the spindle is driven to rotate, thereby rotating the boring bar 1. As the boring bar 1 rotates, the center shafts 10, 11 and the weight 12, which are supported by the steel balls 8, 9 with a preload of 0, also rotate within the hollow part 4 of the boring bar, and if the weight 12 is installed at an appropriate position, a resonance effect is produced. ●Wake up. Then, the tip 6 of the tool 7 attached to the cover 5 at the tip of the boring bar 1 is actually used to temporarily perform machining, and vibrations such as "chattering" are measured. If the mounting position of the weight 12 is at the resonance point, the process proceeds directly to the original processing. If not, remove the cover 5, reset the mounting position of the weight 12 as described above, attach the cover 5, rotate the boring bar 1 again, try machining it, measure the vibration, and find the resonance point. Find it and move on to the original processing. The vibration isolator as described above is actually installed on the boring bar 1.
The results and process of experimentally measuring the difference in vibration between when the boring bar 1 is attached and when it is not attached (that is, when only the boring bar 1 is used) are shown below. Fig. 2A shows an overall view of the boring bar 1 inserted into the spindle head 3, Fig. 2B is a view taken in the direction of arrow I in Fig. 2A, and shows the direction of impulse vibration; Figure 3 (b) shows experimental data in the impulse excitation direction A without a vibration isolator, Figure 4 (a) shows the experimental data in the impulse excitation direction A with a vibration isolator, and Figure 4 (a) shows the impulse vibration in the impulse excitation direction A in Figure 2 (b). Experimental data without a vibration isolator in vibration direction B is shown, and the fourth
Figure B shows experimental data in the impulse excitation direction B with a vibration isolator. The impulse vibration direction A in FIG. Then, an attempt was made to obtain experimental data by hitting the object with a hammer 17 from both directions A and B. Table 1 is listed below, which summarizes the experimental data in Figure 3 A and B and Figure 4 A and B obtained from the above experiment as numerical values.

[Effect of idea]

With the device of the present invention, it has become possible to easily adjust the mounting position of the weights stored in the boring bar. Furthermore, automatic adjustment is possible using the rotation of the main shaft, and preload adjustment can now also be done externally. As a result, it has become possible to provide a boring bar with a vibration isolator that is easy to work with and has a high utility value.

[Brief explanation of drawings]

Fig. 1 shows a partially sectional side view of the first embodiment of the boring bar with a vibration isolator according to the present invention, and Fig. 2A shows an overall view of the boring bar inserted into the spindle head. Figure 3A shows the experimental data in the impulse excitation direction A in Figure 2B without a vibration isolator, and Figure 3B shows the impulse excitation direction. Figure 4A shows the experimental data in direction A with the vibration isolator, Figure 4A shows the experimental data in the impulse excitation direction B in Figure 2B without the vibration isolator, and Figure 4B shows the experimental data in the impulse excitation direction B. Showing experimental data with vibration isolator,
FIG. 5 shows a side sectional view of a boring bar with a vibration isolator according to the second embodiment, FIG. 6 shows a view taken along the - arrow in FIG. 5, and FIG. 7 shows details of the "a" part in FIG. 5. Show the diagram. 1... Boring bar, 4... Hollow part, 5...
Cover, 10, 11... Center axis, 12... Weight, 16... Acceleration pick-up, 30... Boring bar, 31... Rotating ring, 33... Center axis, 34... Weight, 36... Cover, 3
9...Support block, 42...Adjustment screw, 46...
...screw shaft, 47...engaging member, 50...gear, 5
2... Center gear, 54... Cylinder, 55...
Locking body.

Claims (1)

[Scope of utility model registration request] A boring bar having a taper shank formed at one end of a main body and a tool provided at the other end, the boring bar having a cylindrical hollow part formed along the boring bar axis in the boring bar main body, and the boring bar axis inside the cylindrical hollow part. A center shaft rotatably supported on the center shaft, a cylindrical screw inserted and fitted to move on the center shaft and having an engaging portion formed at one end, and an engagement whose one end engages with the cylindrical screw so that only rotation is possible. a weight having a joint portion and movably inserted onto the center shaft; a gear screwed with the cylindrical screw and rotatably supported within the boring bar body; and a gear rotatable around the outer periphery of the boring bar body. a rotation ring that is inserted into the ring and has a gear on the inside and a locking part on the outside;
an internal gear of the rotary ring, an intermediate gear that meshes with the gear and is rotatably supported on the boring bar body; A boring bar with a vibration isolating device, characterized by comprising a rotation stopper that can move forward and backward.