JP2578137Y2 - Line boring bar vibration prevention structure - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration structure for a boring bar in line boring in which a hole is formed with a thin and long tool.

[0002]

2. Description of the Related Art In line boring, the position of a hole to be machined tends to be limited by the size and shape, and the rigidity of a tool tends to be kept low. For this reason, the boring bar vibrates and the surface roughness and hole accuracy of the machined surface often become a problem, and an intermediate support system or a spring pressing system is adopted as a countermeasure against vibration of the boring bar.

[0003]

[Problems to be Solved by the Invention] In the intermediate support method, since the boring bar is inserted, it takes time to align the intermediate support and the tool, and furthermore, there is a slight gap between the intermediate support and the boring bar. Has occurred. For this reason, there is a defect that vibration in the gap range is allowed, and dust enters the gap to cause early abrasion, thereby losing an anti-vibration effect.

In the spring pressing method, the spring retainer and the line bar are brought into close contact with each other through the repulsive force of the spring to change the natural frequency of the boring bar to reduce the vibration in the cutting area. Since only a small repulsive force within a range that does not deform the boring bar can be applied from one side of the boring bar, the system has a small versatility with a small vibration absorbing effect range.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object the purpose of the present invention is to provide a vibration-absorbing effect having a wide range of effects and a simple structure capable of easily maintaining the effect over a long period of time. Another object of the present invention is to provide a vibration preventing structure for a line boring bar.

[0006]

In order to solve the above-mentioned problems, the present invention is a counterweight in which the weight is appropriately adjusted at one end of a pair of levers pivotally supported on a jig. By sandwiching, the natural frequency of the boring bar can be changed in a wide range, and the vibration absorbing effect can be maintained for a long period of time regardless of the wear of the contact pad.

[0007]

In substantially central portion of the length between drive Bush to support head and the tip of driving the [action] boring bar, in a position that does not interfere with the processing, so that it can place the contact pads that sandwich the boring bar, antivibration The support shaft of the lever is provided on the jig.

[0008] A counterweight of approximately the same weight adjusted to the most suitable weight for absorbing the vibration of the boring bar, which varies depending on the cutting conditions, is placed on each of the anti-vibration levers. A structure in which the pinching force of the boring bar is generated at the contact pad at the other end according to the ratio formed with the support shaft of the anti-vibration lever, thereby reducing vibrations that deteriorate the surface roughness of the boring bar being processed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. This embodiment is an embodiment in which two shafts of a bearing hole of an intake / exhaust camshaft of a head cylinder of a natural engine are simultaneously drilled. FIG. 1 is a partial cross-sectional view of a case for accommodating the vibration preventing structure of the present invention.

The case 1 is suspended from the upper part of the jig together with the clamp device C for clamping the work W. The workpiece W transported by a transport device (not shown) is positioned by the locate pin P and placed on the lift arm A. When the boring bar is completely inserted into the bearing hole of the work W, the clamp device C and the case 1 are lowered by an actuator (not shown), the work W is positioned and fixed between the jig base F and the clamp device C, and the contact pad 3 is the case. 1
As a result, the anti-vibration lever rotates about the support shaft 2 to clamp the outer diameter of the boring bar with a desired force.

The case 1 has a pair of anti-vibration levers L1 and L2.
Is pivotally supported by the spindle 2, and the counterweights E1,
E2 and E3 are attached to the left and right pads 3 on the anti-vibration levers L1 and L2 .
The weight is adjusted and fixed in advance so that the holding force becomes substantially equal, and a contact pad 3 is attached to the other end of the vibration-proof lever. In this embodiment, since the bearings of the intake and exhaust camshafts having a small inter-axis pitch are simultaneously drilled, the left and right counterweights are arranged at positions where they do not interfere with each other.

In this way, the boring bar B is pinched with a uniform force to change the natural frequency of the boring bar, and the contact pad 3 generates sliding wear due to the rotation of the boring bar B and the cutting feed. Even
The anti-vibration lever rotates around the support shaft 2 to maintain a constant holding force. Also, a part of the anti-vibration lever is stopped by a stopper 4 so that the contact pad 3 can hold the boring bar B and wait at an interval smaller than the outer diameter of the boring bar.
It is configured to perform positioning adjustment.

A coolant supply passage is provided in the base plate 5, and a discharge port is provided above the contact pad 3 and in the vicinity of the workpiece processing portion so as to wash chips and abrasion powder. Is a V-ring that prevents the splatter from scattering to the top.

Hereinafter, the operation of the vibration preventing structure of the boring bar B configured as described above will be described step by step. The work W conveyed to the processing station is positioned by the lift arm A at a height at which the tool tip of the boring bar B can penetrate the work bearing hole before processing.

Next, a head H to which a boring bar B is attached
Are advanced by a feed unit (not shown) and are inserted through the bearing holes of the work. Thus, the tip of the boring bar B is supported by the drive bush D whose rotational direction is determined by the pin 6.

Next, when the lift arm A descends and the work W positioned on the locate pin P is placed on the jig base F, the clamp device C descends and clamps the work W between the jig bases F. I do. The case 1 also descends similarly to the clamp device C. Due to the lowering of the case 1, the contact pads 3 which stand by at intervals smaller than the outer diameter of the boring bar B
In order to contact the outer diameter of the boring bar B and continue to descend the case 1, the anti-vibration lever rotates about the support shaft 2, and the contact pad 3 is applied with a force in a ratio according to the weight of the counterweight. With the outer diameter of the boring bar B sandwiched, the case 1 stops at a predetermined position and the preparation for machining is completed.

As a result, the contact pad 3 is
The boring bar B provided with the rotational force and the cutting feed can process the bearing hole of the intake / exhaust camshaft of the work to a desired processing diameter and surface roughness while sliding on the contact pad surface.

[0018]

[Effects of the Invention] As described in detail above, the vibration preventing structure of the line boring bar according to the present invention is provided from one side.
Line boring bar
-There is no need to worry about deforming
The vibration absorption effect can be obtained over a wide frequency range, the effect can be easily maintained for a long period of time, and the structure is simple. This is a highly versatile line boring bar vibration prevention structure that can be used for machining.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a case showing a main configuration according to the present invention.

FIG. 2 is a partial cross-sectional view showing the entire configuration of the line boring process according to the present invention.

FIG. 3 is a sectional view of the case as viewed from a III-III section in FIG. 1;

FIG. 4 is a sectional view of the case as viewed from a section taken along line IV-IV of FIG. 1;

[Description of Signs] A Lift arm B Boring bar C Clamping device D Drive bush E1 to E3 Counter weight F Jig base G Guide bar H Head L1, L2 Anti-vibration lever P Locate pin W Work 1 Case 2 Support shaft 3 Contact pad 4 Stopper 5 Base plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) B23B 47/28 B23B 41/12 B23Q 11/00 F16F 15/02

Claims (1)

(57) [Scope of request for utility model registration] 1. A line boring jig for processing a workpiece having a plurality of holes provided at predetermined intervals on a straight line by inserting a line boring bar into each of the holes. substantially at one end of a pair of levers which are supported
A line boring bar vibration prevention structure in which a weight of the same weight is placed and the outer diameter of the boring bar is clamped from both sides at the other end of the lever by the gravity of the weight.