JPH07608U - Vibration prevention structure for line boring bar - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to prevent the surface roughness of the drilling hole from decreasing due to the vibration of the boring bar during line boring processing, to accommodate a wide range of changes in cutting conditions, and to maintain this state without maintenance. It is an object of the present invention to provide a line boring bar vibration absorbing structure having a simple structure that can be formed. [Structure] A counterweight, whose weight is adjusted in advance, is placed on one side of the vibration-proof levers L1 and L2 rotatable around a support shaft 2, and the contact pad at the other end of the vibration-proof lever is mounted by the weight of the counterweight. The vibration prevention structure for the line boring bar is configured to give a force to clamp the outer diameter of the boring bar to 3.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an anti-vibration structure for a boring bar in a line boring process in which a hole is formed with a thin and long tool.

[0002]

[Prior art]

 In line boring, the hole position to be machined is limited by the size and shape, and the rigidity of the 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 intermediate support methods and spring pressing methods have been adopted as anti-vibration measures for boring bars.

[0003]

[Problems to be solved by the device]

 In the intermediate support method, since the boring bar is inserted, it takes time to align the intermediate support and the tool, and moreover, there is a slight gap between the intermediate support and the boring bar. For this reason, there is a drawback that the vibration is allowed within this clearance range, and dust penetrates into this clearance to cause early wear and lose the vibration damping effect.

In the spring pressing method, the spring retainer and the line bar are brought into close contact with each other via the elastic force of the spring to change the natural frequency of the boring bar to reduce the vibration in the cutting area. Since it is possible to apply only a small elastic force within the range that does not deform the boring bar from one side of the boring bar, it is a method with little versatility and a narrow vibration absorbing range.

The present invention has been made to solve the above-mentioned conventional problems, and the purpose thereof is to provide a structure in which a wide range of vibration absorption effect can be easily maintained for a long period of time. It is to provide a simple anti-vibration structure for the line boring bar.

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention is a counterweight in which the weight is appropriately adjusted on one side of a pair of levers pivotally supported on a jig, and by clamping the outer diameter of the boring bar from both sides, The natural frequency can be changed in a wide range, and the vibration absorbing effect can be maintained for a long period of time regardless of wear of the contact pad.

[0007]

[Action]

 The anti-vibration lever is supported so that the contact pad that holds the boring bar can be placed at a position that does not hinder machining, at the center of the length between the head that drives the boring bar and the dry bush that supports the tip. Provide the shaft on the jig.

Counterweights adjusted to the most suitable weight for absorbing the vibration of the boring bar that changes depending on the cutting conditions are mounted on the antivibration levers, and the weights of the counterweights are mounted on the respective antivibration levers. A structure that reduces the vibration that deteriorates the surface roughness of the boring bar during machining by generating the clamping force of the boring bar on the contact pad at the other end according to the ratio with the spindle.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the accompanying drawings. This embodiment is an embodiment in which the two shafts of the bearing holes of the intake and exhaust camshafts of the head cylinder of the natural engine are simultaneously boring processed. FIG. 1 is a view showing a partial cross section of a case accommodating the vibration prevention structure of the present invention.

The case 1 is suspended from the upper part of the jig together with a clamp device C for clamping the work W. The work 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 When the case 3 is lowered, the vibration proof lever 3 rotates about the support shaft 2 to clamp the outer diameter of the boring bar with a desired force.

A pair of anti-vibration levers L1, L2 are pivotally supported on the case 1 by a support shaft 2, and counterweights E1, E2, E3 are fixed to the anti-vibration levers L1, L2 by weight adjustment in advance and fixed. A contact pad 3 is attached to the other end of the swing lever. In this embodiment, since the bearings of the intake / exhaust camshaft having a narrow pitch between the shafts are simultaneously bored, the left and right counterweights are arranged at positions where they do not interfere with each other.

By sandwiching the boring bar B with an even force in this way, the natural frequency of the boring bar is changed, and the contact pad 3 causes sliding wear due to rotation of the boring bar B and cutting feed. Even if it occurs, the anti-vibration lever can rotate around the support shaft 2 and maintain a constant clamping force. Further, the contact pad 3 can hold the boring bar B, and a part of the anti-vibration lever is positioned and adjusted by the stopper 4 so as to stand by at a narrower interval than the outer diameter of the boring bar.

A coolant supply passage is provided in the base plate 5, and a discharge port is provided in the upper portion of the contact pad 3 and around the work processing portion to wash chips and abrasion powder, and 7 is a coolant. It is a V-ring that prevents the above from scattering.

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

Next, the head H to which the boring bar B is attached is advanced by a feed unit (not shown) to be inserted into the bearing hole of the work. In this way, the tip of the boring bar B is supported by the drive bush D whose rotational direction is positioned by the pin 6.

Next, when the lift arm A descends and the workpiece W positioned on the locate pin P is placed on the jig base F, the clamp device C descends to clamp the workpiece W between the jig bases F. To do. The case 1 also descends like the clamp device C. As the case 1 descends, the contact pads 3 waiting at a narrower interval than the outer diameter of the boring bar B come into contact with the outer diameter of the boring bar B, and continue to descend the case 1. Therefore, the anti-vibration lever is supported. Rotating around the shaft 2, the contact pad 3 clamps the outer diameter of the boring bar B with a force according to the weight of the counterweight, and the case 1 stops at a predetermined position and the preparation for processing is completed. To do.

As a result, the boring bar B, which is sandwiched between the contact pads 3 and which is given a rotational force and a cutting feed, slides on the contact pad surface and sucks and exhausts the cam of the workpiece to a desired processing diameter and surface roughness. The shaft bearing hole can be processed.

[0018]

[Effect of device]

 As described in detail above, the vibration preventive structure of the line boring bar according to the present invention has a vibration absorbing effect over a wide frequency range, can easily maintain the effect for a long period of time, and has a simple structure. As shown in this embodiment, this is a vibration-proof structure of a highly versatile line boring bar that can handle simultaneous multi-axis machining at narrow pitches.

[Brief description of drawings]

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

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

FIG. 3 is a cross-sectional view of the case seen from the III-III cross section of FIG. 1.

FIG. 4 is a cross-sectional view of the case as seen from the IV-IV cross section of FIG. 1.

[Explanation of symbols]

 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 Locating pin W Work 1 Case 2 Spindle 3 Contact pad 4 Stopper 5 Base plate

Claims (1)

[Scope of utility model registration request] 1. A line boring machining jig for machining by inserting a line boring bar into each of the above-mentioned holes of a work having a plurality of holes provided at predetermined intervals on a straight line. A vibration prevention structure for a line boring bar in which a weight is placed on one side of a pair of supported levers and the outer diameter of the boring bar is clamped from both sides by the other end of the lever by the weight of the weight.