JP2002361335A - Dimple forming tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to absorb various errors of a machine tool in which the pressure of an indenter is used as an elasticity supporting structure, when a pushing tool (indenter) is chucked in a spindle chuck of a machine tool in general, in substitution for a tool, and a shape of an indenting tool is copied on the surface of a processed good to form a dimpled surface. SOLUTION: Because of an indenter structure elastically supporting the indenting tool, the shape of the indenting toll is copied on the processed good in a largely shrunk state to a moving amount of the spindle chuck of the machine tool. Error factors of the machine tool such as moving accuracy, a temperature drift, and errors of the preprocessed surface of the processed good can be removed, and the accurate indenter that is stable for a long time can be formed even though machine tools having normal accuracy are used therein.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION Lubrication and lubrication are achieved by distributing innumerable dimples with fine irregularities on the surface of parts.
Surface functions such as adhesion / peeling, optics, adhesion, painting, airflow, and heat transfer can be added and improved, but the processing technology for forming this dimple surface is targeted.

[0001]

2. Description of the Related Art Using a general machine tool, an indenter having an indenter at its tip is chucked in place of a cutting tool on a chuck of this spindle, and the indenter is pushed into the surface of a workpiece to transfer the shape of the indenter. Dimples were formed.

[0002]

SUMMARY OF THE INVENTION In general machine tools,
According to the commanded tool trajectory, the tool edge is transferred to the workpiece surface based on the motherhood principle. At this time,
The feature is that the relative rigidity between the tool and the workpiece is designed to be high so that it is accurately transferred to the surface of the workpiece without being affected even if the machining force is large.

[0003] Therefore, when an indenter having an indenter is chucked on the main shaft instead of the tool and pushed into the surface of the workpiece, the tip of the indenter moves according to the command of the machine tool without being elastically deformed. Dimples are formed on the object surface. However, if dimples having a size of about several mm or less, which are the targets of the present invention, are to be formed innumerably on the surface of a wide workpiece, processing takes several tens of hours, during which the machine tool heats by several tens of μm. When forming dimples with minute irregularities, such as deformation, the depth accuracy of the dimples fluctuated, and a highly accurate dimple surface could not be obtained.

[0004]

The principle of the dimple forming tool of the present invention will be described with reference to FIG. In Fig. 1, the horizontal axis indicates the displacement of the indenter, and the vertical axis indicates the pushing force applied from the indenter to the workpiece surface. As described above, general machine tools have high rigidity between the indenter and the workpiece, and have the characteristics of a hard spring. Therefore, even if a very small displacement occurs in the pushing direction, a large change in the pushing force is accompanied. On the other hand, if the elasticity of the indenter is increased and the characteristics of the soft spring are given, the fluctuation of the pushing force can be made relatively small even if a slight displacement occurs in the pushing direction. That is, when the permissible fluctuation of the pushing force ΔF is constant, only a very small fluctuation of the displacement ΔZ ₁ is permissible in a general machine tool, but by increasing the elasticity of the indenter, a large fluctuation of the displacement ΔZ _{2 in the} pressing direction is attained. Is allowed. In the present invention, the indenter of the indenter has an elastic support structure so that various errors of the machine tool can be absorbed.

[0005]

FIG. 2 to FIG. 4 show an embodiment of the present invention. FIG. 2 shows a vertical machining center used to form a dimple by applying the dimple forming tool of the present invention.
Position and speed control in the Z-axis direction is possible. FIG.
Shows an embodiment of the dimple forming tool of the present invention,
It is chucked in part A of Fig. 2. FIG. 4 is a view of the dimple forming tool of FIG. 3 as viewed from below.

The indenter body 6 is a shank 7 having a cylindrical flange below, and the other end of the flange is
Two thin plate-shaped leaf springs 8 are arranged in parallel with two detent pieces 11 interposed at both ends, and are fixed to the flange by four bolts 12. An indenter table 20 having a 0.2 mm diameter sapphire ball indenter 9 fixed to the tip is
Along with two leaf springs having a thickness of 0.08 mm, a width of 7 mm and a length of 22 mm, together with the detent piece 10, bolts 13 are bolted to the center of the leaf springs by bolts 13. The indenter 9 is elastically supported with respect to the indenter body 6. Has been done. In the dimple forming tool having such a configuration, the shank 7 is chucked to the chuck of the spindle incorporated in the spindle head 2 of the machining center.

In this state, the indenter 6 repeatedly advances and retreats in a cyclic manner with respect to the workpiece 14 mounted on the X-axis table 4 of the machining center in response to a command from the NC control device of the machining center. Dimples are formed on the workpiece 14. FIG. 5 shows the movement of the tip of the indenter 9 at this time. That is, the indenter 6 starts moving forward from the retracted retreat end, and accordingly, the tip position of the indenter 9 also approaches the workpiece. When the tip position of the indenter starts to contact the workpiece surface, the indenter body 6
Despite the forward movement at the same speed, the leaf spring 8 undergoes large elastic deformation, the tip of the indenter 9 penetrates into the workpiece at a low speed, and is instructed by the NC control device of the machining center. When the advance end position of the indenter main body 6 reaches a preset end position, the advance is stopped, and the operation proceeds to retreat.
When the retreat end is reached, the workpiece 14 is indexed and positioned by one pitch in the X-axis direction, and the process proceeds to the next dimple forming cycle. By repeating such a cycle operation, a dimple surface is formed.

[0008]

According to the above-described configuration and operation sequence, a control command is given from the NC control device of the machining center 1 and the indenter main body 6 moves to the indenter forward end, but the leaf spring 8 is large. It is elastically deformed, the forward end of the indenter advances at a low speed, and stops at the position of the desired indentation depth. Note that there is a proportional relationship between the distance from the workpiece surface to the forward end of the indenter and the indentation depth. By giving a large displacement control command, highly accurate indentation control can be performed by the elastic deformation reduction mechanism.
It is possible to form dimples with high accuracy. In the case of this embodiment, the rigidity between the indenter body 6 and the indenter 9 is 1.1 k.
In gf / mm, the rigidity between the spindle of the machining center 1 used and the X-axis table 4 is about 1/5000, and the error in the Z direction of the machining center is less than the error in the dimple depth in the present embodiment. It can be suppressed to 10% or less. As described above, by using the dimple forming tool of the present invention, even if the machine tool has a relatively low accuracy, and even if the machine tool is not installed in a special working environment, a high-precision dimple 17 can be obtained. Has the effect of being able to form

FIG. 6 is a plan view showing an example of the dimple surface thus formed, and FIG. 7 is a view showing a cross section taken along line EE in FIG. In this example of the dimple surface, the ratio of the index pitch in the horizontal direction (X-axis direction) to the index pitch in the vertical direction (Y-axis direction) is 3: 1. In addition, it is also possible to form a random dimple surface by giving a control command of the index pitch in the X-axis direction that has been varied from the NC control device of the machining center 1.

FIGS. 8 and 9 show another embodiment of the present invention.
Shown in FIG. 8 is a cross-sectional view of a dimple forming tool capable of measuring a pushing force, and FIG. 9 is a configuration diagram of a detection / control system of the pushing force. A dimple forming tool having substantially the same structure as that shown in FIGS. 3 and 4, but in addition to this, a total of eight strain gauges 15 (strain gauges a, a ', b, b', c, c ', d,
d ') is attached. These strain gauges are connected to a strain meter 16 by forming a bridge as shown in FIG.
The indentation force can be measured. This pushing force is
Maximum pushing force Fm preset on the PC
Compared to ax, when the desired Fmax is reached, the control command from the NC controller is switched from forward to reverse. By doing so, the indentation force can be managed more accurately, and more accurate dimple formation can be achieved.

In the embodiment of the present invention, the indenter 9 is elastically supported by two leaf springs 8. For this reason, when this dimple forming tool is used, vibration may be excited by disturbance from the surroundings. FIG. 10 shows an embodiment of a dimple forming tool having a vibration damping effect against such disturbance vibration. Indenter stand 20,2 leaf springs, the head top of the flat head bolt 21 which couples the de distant piece 10 has a flat shape, the small gap d _g is formed between the indenter body 6 the lower surface This gap is filled with viscous fluid 19. In this way, appropriate vibration damping is performed between the leaf spring 8 and the indenter body 6 by the squeeze effect, and more accurate dimples can be stably formed.

[Brief description of the drawings]

FIG. 1 is a reference diagram for explaining the principle of a dimple forming tool according to the present invention.

FIG. 2 is an explanatory view of a processing machine to which the dimple forming tool of the present invention is applied.

FIG. 3 is an enlarged sectional view of a portion A in FIG. 2 of the tool for forming a dimple according to one embodiment of the present invention.

FIG. 4 is a view of the dimple forming tool in FIG. 3 as viewed from below.

FIG. 5 is a time chart showing the movement of the tip of the indenter.

FIG. 6 is a plan view showing an example of a dimple surface of a turtle pattern formed by a dimple forming tool.

FIG. 7 is a diagram showing a cross section taken along line EE of FIG. 6;

FIG. 8 is a view showing another embodiment of the present invention, which is a dimple forming tool capable of detecting a pushing force.

FIG. 9 is a configuration diagram of detection and control of a pushing force when the dimple forming tool shown in FIG. 8 is used.

FIG. 10 is a dimple forming tool having a vibration damping function according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Machining center 3 Y-axis table 4 X-axis table 5 Spindle 6 Indenter body 7 Shank 8 Leaf spring 9 Indenter 14 Workpiece 15 Strain gauge (a, a ', b, b', c, c ', d, d' (8 strain gauges) 16 Strain meter 17 Dimple 19 Viscous fluid 20 Indenter table

Claims (4)

[Claims] 1. A shank which can be held on a chuck of a machine tool, an elastic body, and an indenter having a molded high-hardness tip. The indenter is elastically supported by the elastic body with respect to the shank. A dimple forming tool for forming a fine uneven surface, which forms a dimple by transferring the shape of the tip of an indenter to an indenter, 2. A dimple surface processing apparatus provided with the dimple forming tool according to claim 1, and a molded product processed by using the processing apparatus. 3. The maximum displacement depth of a tool into a workpiece can be controlled by elastic displacement detecting means for detecting the amount of elastic displacement of a tool in a feed direction of a shank. Item 1. The dimple forming tool according to Item 1. 4. The apparatus according to claim 1, wherein the contact start position of the tool tip with respect to the workpiece is detected by the elastic displacement detecting means, and the pushing depth of the feed mechanism is controlled based on the contact starting position. A dimple forming tool, and a dimple molded article processed using the tool.