JP2008261877A - Jig for measuring cylindrical tool and form accuracy measuring apparatus equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rotate a measured object stably regardless of rotation direction in a jig for measuring a cylindrical tool with use of a roller. <P>SOLUTION: A jig includes: means for holding a measured object by at least two parts of the cylindrical side surface thereof; means for positioning the bottom surface of the measured object; and a roller, attached to a rolling mechanism having an axis of rotation parallel to the axis of rotation of the measured object, which serves to rotate the measured object, the roller being made of an elastic body, and shaped into such a conical trapezoid that the diameter of a portion of the roller that faces a measured portion of the measured object is smaller than the diameter of a portion of the roller that is opposite the measured portion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to cutting edge inspection, blade diameter measurement, concentricity measurement, or cylindricity of a cutting tool having a cylindrical holding portion such as a drill or an end mill (such a tool is generally referred to as a “cylindrical tool”). The present invention relates to a jig for performing measurement and the like, and a shape accuracy measuring device incorporating the jig.

  In order to accurately perform edge inspection and blade diameter measurement of a cylindrical tool such as a drill or an end mill, it is necessary to rotate the object to be measured with its axis center kept stable.

In the conventional shape accuracy measuring instrument, the following method has been used to rotate the object to be measured. That is, (1) a cylindrical side surface for holding an object to be measured by a collet chuck or the like having a rotational driving force (in the case of a cutting tool, it is a portion generally called “shank”. The “cylindrical side surface for holding the object to be measured” is hereinafter referred to as “shank”) and the object to be measured is rotated (eg, Patent Document 1), (2) the shank is V Friction between the roller and the shank by placing a roller with a rotating mechanism on the jig shaped jig or bearing and having a rotation mechanism whose axis is parallel to the rotation axis of the object to be measured. This is a method of rotating the object to be measured with force.
JP-A-62-172206

  FIG. 4 is a side view showing the method (1). In this method, the shank 1a of the object to be measured 1 is held by a collet chuck 2 having a rotational driving force, and the object to be measured 1 is rotated by the rotation of the collet chuck.

  Such a method using a collet chuck is an excellent method in terms of rotational stability, that is, transmission without losing the rotational force of the drive source, and that there is no shake of the measurement object during rotation. . However, on the other hand, (a) the structure of the collet chuck with rotational driving force itself is complicated, and as a result, it becomes very expensive, and (b) it takes time and effort to detach the measured object and make subsequent adjustments. In addition, there are problems such as that (c) it is necessary to prepare and replace different types of collet chucks in order to cope with a wide variety of objects to be measured. In view of the fact that the field of measurement technology to which the present invention belongs basically has a non-productive character, and that the problem of cost reduction must be fully considered for its practical use. This method, which cannot essentially avoid these big economic problems, is not suitable for application in the field of inspection and measurement.

  FIG. 5 is a front view (a) and a side view (b) showing a state in which the object to be measured 1 is installed in the method of (2), that is, a cylindrical tool measuring jig according to the prior art using a roller. ). The shank 1a of the object to be measured 1 is arranged on a V-shaped jig 3 which is a means for holding it, and a rotation mechanism (not shown) whose axis is parallel to the rotation axis of the object to be measured. The surface 4a parallel to the rotation axis Xa of the roller 4 is brought into surface contact at an arbitrary position of the shank 1a. And when a roller rotates, it is a mechanism that a to-be-measured object also rotates with the frictional force which generate | occur | produces between the surface 4a and the shank 1a.

  A method using such a roller has a simple structure and can be manufactured at low cost, and thus is suitable for a field intended for inspection and measurement. However, in the conventional technique, unless the rotation axis of the roller and the rotation axis of the object to be measured are made completely parallel, the object to be measured is not stabilized on the shank holding means, and the shank bottom surface 1c. Or the subject that it moved to the rotating shaft direction of either the to-be-measured part 1b occurred.

  FIGS. 6 and 7 are a front view (a), a top view (b), and a schematic diagram (c) showing a direction of a force acting on the object to be measured, for explaining the problems of the prior art using a roller. .

  For example, when the rotation axis Xa of the roller, the rotation direction Dr, and the rotation axis Xb of the object to be measured have a relationship as shown in FIGS. 6A and 6B, the object 1 has a direction of the shank bottom surface 1c. Move to. As shown in the schematic diagram of FIG. 6C, this is because the driving force F generated by the friction between the roller surface and the shank is a component Ft in the direction perpendicular to the rotation axis Xb of the object to be measured, that is, This is because it includes not only the torque force that rotates the object to be measured 1 but also the thrust force Fs that is parallel to the rotation axis Xb and acts in the direction of the shank bottom surface 1c of the object to be measured 1.

  On the contrary, when the rotation axis Xa of the roller, the rotation direction Dr, and the rotation axis Xb of the object to be measured are in the relationship as shown in FIGS. 7A and 7B, the object 1 to be measured is measured. Move in the direction of portion 1b. In contrast to the case described with reference to FIG. 6, as shown in FIG. 7C, the driving force F for rotating the measurement object 1 is parallel to the rotation axis Xb and the measurement object 1 is measured. This is because the thrust force Fs acting in the direction of the portion 1b is included.

  If only the rotation direction of the roller is reversed in the case of FIG. 6, the thrust force acting on the object to be measured becomes the same direction as in FIG. 7, and conversely, only the rotation direction of the roller in the case of FIG. Is reversed, the thrust force acting on the object to be measured is in the same direction as in FIG.

  For this reason, in the conventional technology using a roller, a method has been adopted in which the thrust force acting on the object to be measured is reversely used to obtain a stable rotation of the object to be measured.

  For example, as shown in FIG. 8, the rotation axis Xa of the roller, the rotation direction Dr, and the rotation axis Xb of the object to be measured are arbitrarily adjusted so as to have a relationship as shown in FIGS. 6 (a) and 6 (b). And it is the method of pressing the shank bottom face 1c of the to-be-measured object 1 against the pin 5 for determining the position. In this method, as described with reference to FIG. 6, when the object to be measured 1 rotates, a thrust force that moves the object to be measured 1 in the direction of the shank bottom surface 1c works, and the bottom surface 1c of the shank 1 is always pinned. Since it contacts 5, stable rotation can be obtained.

  However, in this method, if the rotation direction of the roller is reversed, the thrust force acting on the object to be measured is also reversed. In this case, there is a fatal defect that the object to be measured is separated from the pin. This makes it impossible to repeat normal rotation and reversal at all, and for example, it has been impossible to accurately and efficiently perform edge inspection and blade diameter measurement of cutting tools such as drills and end mills.

  The inventor of the present application accumulates trial and error on the above problem, that is, the problem of stably rotating the object to be measured regardless of the rotation direction of the roller in the method using the roller. Technology was developed. That is, a cylindrical tool measuring jig according to the present invention is a jig used in a shape accuracy measuring device of a cylindrical tool, and means for holding at least two locations on the cylindrical side surface of the object to be measured; And a roller for rotating the object to be measured attached to a rotating means having a rotation axis parallel to the rotation axis of the object to be measured. And the shape thereof has a truncated cone shape in which the roller diameter on the side opposite to the measurement part is larger than the roller diameter on the measurement part side of the object to be measured.

  Furthermore, it is desirable that the elastic body constituting the roller is rubber.

  By adopting the configuration of the present invention, it is possible to stably rotate the object to be measured regardless of the rotation direction of the roller, which is conventionally impossible with a method using a roller. Tool edge inspection and blade diameter measurement can be performed accurately and efficiently. For example, when detecting the tip of the cutting edge using image recognition or the like, the object to be measured is rotated at high speed, the tip position is detected, and then the precise position is detected by reversing at low speed. It becomes possible.

  Hereinafter, the best mode for carrying out the present invention will be described in detail.

(First embodiment)
FIG. 1 is a front view (a) and a side view (b) showing a state in which an object to be measured 1 is installed in a jig according to a first embodiment of the present invention. The basic configuration is the same as that shown in FIG. That is, the present invention includes a jig 3 that is a means for holding the shank 1a of the object 1 to be measured, a rotating means (not shown) having a rotation axis Xa parallel to the rotation axis Xb of the object 1 to be measured, and this rotation. A roller 4 that is attached to the means and rotates the object 1 by surface contact at an arbitrary position of the shank 1a of the object 1 to be measured, and a pin 5 that determines the position of the shank bottom surface 1c of the object to be measured. I have.

  In the present invention, the roller 4 is made of an elastic body, and the shape thereof has a truncated cone shape in which the roller diameter on the shank bottom surface 1c side is larger than the roller diameter on the measurement target part 1b side.

  The elastic body constituting the roller 4 is in direct contact with and rotates the object to be measured, and is preferably rubber or a rubber-like substance from the viewpoint of protecting the object to be measured. Specifically, a synthetic polymer material exhibiting rubber-like elasticity is suitable, such as styrene-butadiene rubber, butadiene rubber, butyl rubber, ethylene-propylene rubber, nitrile rubber, chloroprene rubber, fluorine rubber, silicone rubber, urethane rubber, and the like. Can be mentioned.

  The roller 4 is shaped like a truncated cone having a larger roller diameter on the shank bottom surface 1c side than the roller diameter on the measured part 1b side. Regardless of the rotation direction, a thrust force in the direction of the shank bottom surface 1c can always be applied to the object to be measured.

  FIG. 2 is a side view (a), a top view (b), and a top view (c) schematically showing the action of the roller according to the jig of the present invention. As shown in FIG. 2 (a), the roller 4 pressed against the shank 1a is deformed by its elasticity. At this time, the torque force Ft for rotating the object to be measured 1 is on the side where the roller diameter is large. That is, since the shank bottom surface 1c side is larger than the roller diameter side, that is, the measured portion 1b side, the driving force F applied to the measured object 1 does not coincide with the direction of the torque force Ft. It is considered that a thrust force Fs in the direction of the shank bottom surface 1c, which is a direction in which a larger torque force is applied, acts on the measurement object 1 (FIG. 2B). In addition, even when the rotation direction is reversed, the driving force F ′ applied to the object to be measured 1 is only in a bilaterally symmetric direction with respect to the rotation axis Xb of the object to be measured 1, and thus is applied to the object to be measured 1. The direction of the thrust force Fs does not change (FIG. 2 (c)).

  Thus, when rotating the object to be measured, in order to always give a thrust force in the direction of the bottom surface of the shank, a truncated cone shape in which the roller diameter on the bottom surface side of the shank is larger than the roller diameter on the portion to be measured side. However, as can be understood from the above description, the same effect can be obtained if the diameter of the roller continuously increases from the portion to be measured toward the bottom surface of the shank. It is done. In other words, the large diameter part and the small diameter part of the roller do not necessarily change linearly, but change in a curved or concave shape, and as a result, strictly satisfy the definition of a truncated cone as a geometric term. You don't have to.

  Specific numerical values of the roller width, the large diameter, and the small diameter are appropriately left to the design, and examples of specific design guidelines are given below.

  That is, in the present invention, the rotation axis of the roller and the rotation axis of the object to be measured are not strictly parallel, and the rotation axis Xa of the roller, the rotation direction Dr, and the rotation axis Xb of the object to be measured are the same as those in FIG. When the relationship is as shown in (b), as described above, a thrust force is applied to the object to be measured 1 so as to move it in the direction of the part to be measured 1b. This thrust force is affected by the amount of deviation between the rotation axes of the roller and the object to be measured.On the other hand, in the present invention, due to the difference between the diameter of the roller to be measured and the diameter of the shank bottom surface, Since the magnitude of the thrust force in the direction changes, the size of both diameters may be appropriately determined in consideration of the predicted shift amount of the respective rotation axes of the roller and the object to be measured.

  For example, the jig designed by the inventors of the present application has a specification that can measure a tool having a shank diameter of 4 to 20 mm, and the roller has a width of 3 mm, a large diameter of 22 mm, and a small diameter of 20 mm. These specific numerical values can be appropriately designed as described above, but considering the ease of manufacture, the width is 1 to 5 mm, the large diameter is 10 to 30 mm, and the small diameter is 1 to 3 mm smaller than the large diameter. It is recommended.

  In the present invention, when the measurement object is rotated by the rotation of the roller, a thrust force in the shank direction is always applied to the measurement object regardless of the rotation direction. In view of this, stable rotation can be obtained by arranging a pin, which is a means for determining the position of the bottom surface of the shank of the object to be measured, so that the bottom surface of the shank is always in contact with the pin. Note that this positioning means is not limited to a pin, and may be a plate-like member, for example, but if the contact area with the shank bottom surface becomes too large, a loss of rotational force due to frictional force occurs, so the object to be measured In view of the diameter and the like, means such as using a pin having a spherical tip can be appropriately employed.

  In addition, as a method of installing the jig of the present invention in the measuring device, not to place the object to be measured horizontally, but to install it vertically, in order to prevent the object to be measured from falling due to its own weight, Must be received by the bottom surface of the shank, and a pin or plate-like member for that purpose also serves as a means for determining the position of the bottom surface of the shank. In this case, since the weight of the object to be measured is added to the thrust force generated when the object to be measured rotates on the pin or plate-like member, the frictional force with the bottom surface of the shank is more than that when the object to be measured is placed horizontally. Becomes larger. For this reason, in consideration of the diameter and weight of the object to be measured, the positioning means has a structure that rotates together with the object to be measured by holding the pin with a bearing or the like in addition to using a pin having a spherical tip. Such means can be employed as appropriate.

(Second embodiment)
FIG. 3 is a front view (a) and a side view (b) showing a state in which the DUT 1 and the pins 5 are installed in the jig according to the second embodiment of the present invention. As described above, the means for holding the shank 1a of the object to be measured 1 may be arranged on the bearing 6 in place of the V-shaped jig as shown in the jig 3. Absent.

  Note that the shank 1a of the DUT 1 may be held at least at two places, but it may be at three or more places.

  Further, the rotating means for attaching the roller 4 is not particularly specified, and any known technique can be appropriately employed regardless of whether it is manual or automatic such as a known motor.

They are the front view (a) and the side view (b) which show the state which installed the to-be-measured object and the pin in the jig | tool which concerns on 1st embodiment of this invention. It is the side view (a), top view (b), and top view (c) which show typically the effect | action of the roller which concerns on the jig | tool of this invention. It is the front view (a) and side view (b) which show the state which installed the to-be-measured object and the pin in the jig | tool which concerns on 2nd embodiment of this invention. It is a side view of the cylindrical tool measuring jig based on the prior art using a collet chuck. It is the front view (a) and side view (b) which show the state which installed the to-be-measured object in the cylindrical tool measurement jig | tool which concerns on the prior art using a roller. It is the front view (a) for demonstrating the subject of the prior art using a roller, a top view (b), and the schematic diagram (c) which shows the direction of the force which acts on a to-be-measured object. It is the front view (a) for demonstrating the subject of the prior art using a roller, a top view (b), and the schematic diagram (c) which shows the direction of the force which acts on a to-be-measured object. It is the front view (a) and top view (b) which show the state which installed the to-be-measured object and the pin in the cylindrical tool measurement jig | tool which concerns on the prior art using a roller.

Explanation of symbols

1 Measurement object 1a Measurement object holding part (shank)
1b Measurement object part 1c Measurement object shank bottom surface 3 Measurement object holding jig (V-shaped jig)
4 Roller 5 Shank bottom positioning pin 6 Measuring object holding jig (bearing)
Xa Roller rotation axis Xb Measurement object rotation axis

Claims (3)

  A jig used in a shape accuracy measuring device for a cylindrical tool, means for holding at least two positions on the cylindrical side surface of the object to be measured, means for determining the position of the bottom surface of the object to be measured, and rotation of the object to be measured In a jig provided with a roller for rotating the object to be measured attached to a rotation mechanism having a rotation axis parallel to the axis, the roller is made of an elastic body, and the shape thereof is measured by the object to be measured. A cylindrical tool measuring jig characterized by having a truncated cone shape in which the roller diameter on the side opposite to the measurement part is larger than the roller diameter on the part side.   The cylindrical tool measuring jig according to claim 1, wherein the elastic body constituting the roller is rubber.   A shape accuracy measuring device comprising the cylindrical tool measuring jig according to claim 1.

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