JP2023045902A - Screw shaft glossiness degree evaluation device - Google Patents

Abstract

To provide a non-conventional practical screw shaft glossiness degree evaluation device.SOLUTION: A device, which is for evaluating a glossiness degree of a screw shaft 30 in a ball screw, an irradiation unit 1 that irradiates a screw groove surface 30a of the screw shaft 30 targeted for evaluation with laser light; a light reception unit 2 that receives reflection light of the laser light irradiated from the irradiation unit 1 upon the screw groove surface 30a; and a reflection rate calculation unit that calculates a reflection rate from an amount of light of the reflection light received by the light reception unit 2, and an amount of light of reflection light, serving as a reference, to be set based on a radius of curvature of a screw groove width direction concave curvature edge in the screw groove surface 30a of the screw shaft 30 targeted for evaluation and a radius of curvature of a screw groove spiral direction convex curvature edge therein.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a screw shaft glossiness evaluation device for evaluating the glossiness of a screw shaft in a ball screw.

One of the completion inspection items in the manufacturing process of the screw shaft of the ball screw is the glossiness of the screw groove surface.

Conventionally, as a method for evaluating the glossiness of the thread groove surface of the screw shaft, for example, a skilled inspector visually judges the quality based on the experience and feeling, or the glossiness is judged to be good in advance. Visual evaluation by human beings has been carried out, such as judging the quality by comparing it with a sample that has been prepared. There is a problem that the evaluation results may differ depending on the inspector, and the evaluation results may vary even by the same inspector.

By the way, conventionally, there has been proposed a glossiness measuring device (hereinafter referred to as a conventional example) for measuring glossiness from the amount of reflected light of irradiated laser light as disclosed in Patent Document 1, for example. This conventional example is based on the premise that the measurement site irradiated with the laser beam is flat. cannot be evaluated favorably.

Japanese Utility Model Laid-Open No. 3-65954

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and provides a practical apparatus for evaluating the glossiness of screw shafts that has never existed before.

The gist of the present invention will be described with reference to the accompanying drawings.

An apparatus for evaluating the glossiness of a screw shaft 30 in a ball screw, comprising an irradiation unit 1 for irradiating a thread groove surface 30a of the screw shaft 30 to be evaluated with a laser beam, and a laser beam irradiated from the irradiation unit 1. A light receiving portion 2 for receiving the reflected light of the laser beam on the thread groove surface 30a, the amount of the reflected light received by the light receiving portion 2, and the screw on the thread groove surface 30a of the screw shaft 30 to be evaluated. a reflectance calculating unit for calculating the reflectance from the reference amount of reflected light set based on the radius of curvature of the concave curved edge in the groove width direction and the radius of curvature of the convex curved edge in the spiral direction of the thread groove. It relates to a screw shaft glossiness evaluation device characterized by the following.

Further, in the apparatus for evaluating screw shaft glossiness according to claim 1, the amount of light of the reflected light serving as the reference is determined by assuming that the thread groove surface 30a of the screw shaft 30 to be evaluated is a mirror surface. This is an apparatus for evaluating screw shaft glossiness, characterized in that it is set based on the radius of curvature of a concave curved edge in the groove width direction and the radius of curvature of a convex curved edge in the spiral direction of a groove surface 30a.

Further, in the apparatus for evaluating screw shaft glossiness according to any one of claims 1 and 2, a base portion 3 on which the irradiation portion 1 and the light receiving portion 2 are provided, and the screw is provided opposite to the base portion 3. A screw shaft bearing portion 4 for supporting a shaft 30 is provided, and the relative positions of the irradiation portion 1 and the light receiving portion 2 provided on the base portion 3 and the screw shaft 30 supported by the screw shaft bearing portion 4 are controlled. The present invention relates to a device for evaluating screw shaft glossiness, characterized in that it is configured to be adjustable.

Further, in the apparatus for evaluating screw shaft glossiness according to claim 3, the base portion 3 is provided with a first linear direction X as a parallel movement direction with respect to the screw shaft 30 supported by the screw shaft support portion 4, A second linear direction Y perpendicular to the linear direction X and perpendicular to the screw shaft 30 supported by the screw shaft support portion 4, and vertical movement perpendicular to the first linear direction X and the second linear direction Y. A movable part that enables movement in the third linear direction Z as a direction and enables adjustment of the relative positions of the screw shaft 30 supported by the irradiation part 1 and the light receiving part 2 and the screw shaft support part 4 5 is provided.

Further, in the apparatus for evaluating screw shaft glossiness according to claim 4, the movable part 5 is configured to vertically rotate the base part 3. It is related.

Further, in the screw shaft glossiness evaluation device according to any one of claims 3 to 5, the screw shaft support part 4 is configured to support the screw shaft 30 in a horizontal state, and further, An apparatus for evaluating screw shaft glossiness characterized by comprising a vertical rotation mechanism for vertically rotating the supported screw shaft 30 and a horizontal rotation mechanism for horizontally rotating the supported screw shaft 30. It is.

Since the present invention is configured as described above, it is possible to quantitatively evaluate the glossiness of a screw shaft, thereby providing a practical screw shaft glossiness evaluation apparatus that has never existed before.

It is a top view which shows a present Example. It is a side view which shows a present Example. FIG. 3 is an explanatory diagram of the main part of the embodiment; FIG. 4 is an explanatory diagram of a usage state of the embodiment; FIG. 4 is an explanatory diagram of a usage state of the embodiment; FIG. 3 is an explanatory diagram of the main part of the embodiment; FIG. 3 is an explanatory diagram of the main part of the embodiment; FIG. 3 is an explanatory diagram of the main part of the embodiment; FIG. 4 is an explanatory diagram of a usage state of the embodiment; FIG. 4 is an explanatory diagram of a usage state of the embodiment; FIG. 3 is an explanatory diagram of the main part of the embodiment; FIG. 3 is an explanatory diagram of the main part of the embodiment; FIG. 3 is an explanatory diagram of the main part of the embodiment; FIG. 11 is an operation explanatory diagram of another embodiment; FIG. 11 is an operation explanatory diagram of another embodiment; FIG. 3 is an explanatory diagram of the main part of the embodiment; 4 is an explanatory diagram of the relationship between the irradiation position of laser light and the amount of light received in the light receiving unit 2 according to the embodiment; FIG. FIG. 3 is an explanatory diagram of the intensity distribution and light amount of laser light according to the present embodiment; FIG. 3 is an explanatory diagram of spread of laser light according to the present embodiment; FIG. 3 is an explanatory diagram of spread of laser light according to the present embodiment; FIG. 4 is an explanatory diagram of the intensity distribution of reflected light and the amount of received light according to the embodiment; FIG. 4 is an explanatory diagram of the relationship between the glossiness and the amount of reflected light;

A preferred embodiment of the present invention will be briefly described with reference to the drawings showing the operation of the present invention.

The present inventor paid attention to the two curvature radii (curvature radius of the concave curved edge in the width direction of the thread groove and curvature radius of the convex curved edge in the spiral direction of the thread groove) set on the thread groove surface 30a when manufacturing the screw shaft 30, I completed the present invention.

That is, when a laser beam is irradiated from the irradiation unit 1 toward the measurement point of the thread groove surface 30a of the screw shaft 30, and the reflected light reflected by the thread groove surface 30a is received by the light receiving unit 2, this light receiving unit 2, the radius of curvature of the concave curved edge in the width direction of the thread groove and the radius of curvature of the convex curved edge in the spiral direction of the thread groove surface 30a of the screw shaft 30 to be evaluated. The reflectance is calculated by the reflectance calculator from the amount of reflected light serving as a reference, and the glossiness of the thread groove surface 30a is evaluated based on this reflectance.

Therefore, for example, it is possible to quantitatively evaluate whether or not the glossiness is required for the screw shaft 30 produced in a lot.

A specific embodiment of the present invention will be described with reference to the drawings.

In this embodiment, a cylindrical ball screw nut having spirally formed ball rolling grooves (screw grooves forming an endless circulation path) on the inner peripheral surface, and a ball rolling groove (screw groove 30') on the outer peripheral surface. ) is a device for evaluating the glossiness of the screw shaft 30 in a ball screw composed of a screw shaft 30 formed in a spiral shape and a plurality of balls provided between the ball screw nut and the screw shaft 30 There is an irradiation unit 1 that irradiates a laser beam on the thread groove surface 30a (rolling surface) of the screw shaft 30 to be evaluated, and the reflected light of the laser beam irradiated from the irradiation unit 1 on the thread groove surface 30a. The light receiving portion 2 that receives light, the amount of reflected light received by the light receiving portion 2, the radius of curvature of the concave curved edge in the thread groove width direction and the convexity in the thread groove spiral direction on the thread groove surface 30a of the screw shaft 30 to be evaluated. and a reflectance calculator for calculating the reflectance from the reference amount of reflected light that is set based on the radius of curvature of the curved edge.

In this embodiment, as the thread groove surface 30a of the screw shaft 30, a thread groove surface 30a having a shape in which two circular arcs are overlapped (commonly known as a Gothic arch shape) is adopted. For example, 30a may be used as long as it exhibits the characteristics of this embodiment.

Specifically, in this embodiment, as shown in FIGS. 1 and 2, the irradiation unit 1 and the light receiving unit 2 are provided on the upper part of the square plate-shaped base part 3, and are positioned opposite to the screw shaft support part 4, which will be described later. The relative positions of the irradiation section 1 and the light receiving section 2 provided on the base section 3 and the screw shaft 30 supported by the screw shaft support section 4 can be adjusted.

The optical axis of the irradiation unit 1 and the optical axis of the light receiving unit 2 are provided in the same plane as the measurement axis lc as shown in FIG.

Each optical axis is aligned with a straight line lt or ls which is inclined by an angle ε (angle of incidence and angle of reflection) with respect to the measurement axis lc and whose origin is the focal point O. FIG.

Also, the base portion 3 on which the irradiation portion 1 and the light receiving portion 2 are provided is provided above the device main body 10 via the movable portion 5 .

The movable portion 5 includes a first linear direction X (horizontal direction) as a translation direction with respect to the screw shaft 30 supported by the screw shaft bearing portion 4, and a screw that is perpendicular to the first linear direction X and supported by the screw shaft bearing portion 4. Movement in a second linear direction Y (front-rear direction) as a separation movement direction with respect to the axis 30 and movement in a third linear direction Z (vertical direction) orthogonal to the first linear direction X and the second linear direction Y and as a vertical movement direction , and the relative positions of the irradiation unit 1 and the light receiving unit 2 and the screw shaft 30 supported by the screw shaft support unit 4 can be adjusted.

FIGS. 14 and 15 show another embodiment, in which the movable portion 5 is configured to vertically rotate the base portion 3 to the left and right (rotate in the vertical plane about a horizontal axis perpendicular to the axis of the screw shaft 30). Furthermore, the irradiation unit 1 and the light receiving unit 2 are also provided at appropriate positions (positions where the measurement axis is 45 degrees with respect to the axis of the screw shaft 30).

As shown in FIGS. 1 and 2, the screw shaft support portion 4 is configured to support the screw shaft 30 in a horizontal state in which the axis is horizontal. A vertical rotation mechanism that rotates in a vertical plane around a horizontal axis orthogonal to the axis, and a screw shaft 30 that is supported horizontally rotates (rotates in a horizontal plane around a vertical axis that is orthogonal to the axis). and a horizontal rotation mechanism that allows the

Specifically, a support base member 4b is horizontally rotatably provided at a position opposed to the base portion 3 (irradiating portion 1 and light receiving portion 2) in the upper portion of the apparatus main body 10, and a screw shaft 30 supported thereon is horizontally rotated. A pair of support members 4a for mounting and supporting the screw shaft 30 in a suspended state are provided on the upper left and right positions of the support base member 4b, and the supported screw shaft 30 is vertically rotated. It is configured as a rotating mechanism.

An inverted triangular concave portion 4a' for fitting and locking the screw shaft 30 is provided in the upper portion of the support member 4a so as to support the screw shaft 30 stably.

Therefore, the screw shaft bearing portion 4 is arranged so that the normal ln at the measurement point M of the screw shaft 30 is in the same direction as the measurement axis lc, the width direction of the screw groove is the X direction, and the spiral direction of the screw groove is the Z direction. It has a structure that can hold the screw shaft 30 .

Therefore, when measuring the gloss at the bottom (lowest part) of the screw groove 30', the screw shaft support 4 tilts the screw shaft 30 by the lead angle βb on the measurement point M as shown in FIGS. keep it in place. On the other hand, when measuring the gloss at the ball contact portion of the thread groove 30', the screw shaft bearing portion 4 was tilted by the lead angle βc on the measurement point M and rotated by the contact angle α as shown in FIGS. keep in state.

In addition, as described above, the present embodiment is based on the amount of reflected light received by the light receiving unit 2 and the radius of curvature of the thread groove surface 30a of the screw shaft 30 to be evaluated in two mutually orthogonal directions (thread groove width direction A reflectance calculation unit (not shown computer system).

Specifically, assuming that the thread groove surface 30a of the screw shaft 30 to be evaluated is a mirror surface, the amount of reflected light that serves as a reference is the curvature of the concave curved edge in the thread groove width direction of the thread groove surface 30a. It is set based on the radius and the radius of curvature of the convex curved edge in the spiral direction of the thread groove. amount of reflected light)×100%.

Reference numeral 6 is an amplifier section, and 7 is an oscilloscope.

The usefulness of the screw shaft glossiness evaluation apparatus according to the present embodiment having the above configuration will be described.

With the screw shaft 30 supported by the screw shaft support portion 4, as shown in FIG. The position of the base portion 3 in the Y direction is adjusted by moving the movable portion 5 so that the distances LM to the measuring point _M of are equal.

Subsequently, the position of the base portion 3 in the X and Z directions is roughly adjusted by moving the movable portion 5 so that the laser beam is irradiated near the measurement point M on the screw shaft 30, and then the measurement point is adjusted. The position of the base plate is finely adjusted in two directions of X and Z until the normal line ln of M and the measurement axis lc coincide.

As shown in FIG. 17, when the normal line ln of the measurement point M is deviated from the measurement axis lc, the direction of the reflected light is shifted and the amount of light received by the light receiving unit 2 decreases. Since the amount of received light reaches its peak when the axis lc coincides, the peak amount of received light can be obtained by adjusting the position of the base portion 3 in the two directions of X and Z while checking the value of the amount of received light with an oscilloscope 7 or the like. can be measured.

The laser light emitted from the irradiation unit 1 has a light quantity distribution shape as shown in FIG.

Here, _I0 represents the light intensity at the center of the laser beam, and _ω0 represents the value of r when the value of I is 0.135 times _I0 . The values of I ₀ and ω ₀ can be obtained by measuring the distribution waveform of laser light.

Also, the area _A0 in FIG. 18 is represented by the following equation (2).

Here, r ₀ represents the radius of the condensing lens in the light receiving section 2 , which is the light amount detection range of the light receiving section 2 .

Therefore, the total light quantity _V0 of the irradiated laser light is represented by the following equation (3), and this value is equal to the light receiving quantity of the light receiving section 2 when the plane mirror is irradiated with the laser light.

The irradiated laser beam is reflected at a measurement point M having two orthogonal curvature radii (curvature radius of concave curved edge in the width direction of the thread groove and curvature radius of convex curved edge in the spiral direction of the thread groove), thereby forming a screw. 19 and 20, and becomes an ellipse with a major axis a and a minor axis b at the position of the light receiving portion 2. As shown in FIGS.

Here, the lengths of a and b are determined by the values of the curvature radii r _a and r _s at the measurement point M, respectively.

Therefore, the light amount distribution of the reflected light at the position of the light receiving section 2 changes from the distribution shown in FIG. 18 to an elliptical distribution shape as shown in FIG. Assuming that the measurement point M has a reflectance of 100% (mirror surface), I is expressed by the following equation (4).

Here, _I1 represents the amount of light at the center of the laser beam, and ω(θ) represents the value of r when the value of I is 0.135 times _I1 at the angular position θ. The values of I ₁ and ω(θ) can be calculated from the above equation (1) and the values of a and b.

Also, the area _A1 in FIG. 21 is represented by the following equation (5).

Therefore, the light amount _V1 of the reflected light entering the condenser lens of the light receiving section 2 is expressed by the following equation (6), and this value is the amount of light received by the light receiving section 2 when the measurement point M has a reflectance of 100% (mirror surface). equal to

Therefore, the reflectance γ at the measurement point M is (actual reflected light amount V _P )/(reflected light amount V ₁ in the case of a mirror surface)×100%, and is calculated by the following equation (7). can do.

FIG. 22 shows the reflectance (amount of received light/amount of irradiated light x 100%) of a test piece (flat plate made of stainless steel) measured using the irradiation unit 1 and the light receiving unit 2 according to the present embodiment, and shows a general-purpose It compares the measured values of gloss when measured with a gloss meter (PG-1M manufactured by Nippon Denshoku Industries Co., Ltd.). From this figure, it can be seen that the reflectance measured with laser light has a high correlation with the glossiness measured with a general-purpose gloss meter, regardless of the surface properties of the test piece and the incident/reflection angles of the light source. Therefore, it is considered that the degree of glossiness of the surface can be evaluated by the reflectance of laser light in the same manner as when measured with a glossmeter.

Since the present embodiment is constructed as described above, the irradiation unit 1 irradiates a laser beam toward the measurement point on the thread groove surface 30a of the screw shaft 30, and the laser beam is reflected by the thread groove surface 30a. When light is received by the light receiving unit 2, the amount of reflected light received by the light receiving unit 2, the curvature radius of the groove width direction concave curved edge on the thread groove surface 30a of the screw shaft 30 to be evaluated, and the thread groove spiral direction convexity The reflectance is calculated by the reflectance calculator from the amount of reflected light that is a reference set based on the radius of curvature of the curved edge, and this reflectance is used as an evaluation criterion.

Therefore, according to the present embodiment, it is possible to quantitatively evaluate whether or not the glossiness is required for the screw shaft 30 produced in a lot, for example.

It should be noted that the present invention is not limited to this embodiment, and the specific configuration of each component can be appropriately designed.

X First linear direction Y Second linear direction Z Third linear direction 1 Irradiation part 2 Light receiving part 3 Base part 4 Screw shaft bearing part 5 Movable part
30 screw shaft
30a thread groove surface

Claims (6)

An apparatus for evaluating the glossiness of a screw shaft of a ball screw, comprising an irradiation unit for irradiating a thread groove surface of the screw shaft to be evaluated with a laser beam, and the screw irradiated with the laser beam from the irradiation unit. A light-receiving portion that receives reflected light from the groove surface, the amount of the reflected light received by the light-receiving portion, the radius of curvature of the concave curved edge in the thread groove width direction on the thread groove surface of the screw shaft to be evaluated, and A screw shaft glossiness evaluation, characterized by comprising a reflectance calculation unit for calculating the reflectance from the amount of reflected light serving as a reference set based on the curvature radius of the convex curved edge in the spiral direction of the screw groove. equipment. 2. The apparatus for evaluating screw shaft glossiness according to claim 1, wherein the amount of light of the reflected light serving as the reference is the amount of light on the thread groove surface of the screw shaft to be evaluated, assuming that the thread groove surface of the screw shaft to be evaluated is a mirror surface. A device for evaluating screw shaft glossiness, characterized in that it is set based on the radius of curvature of a concave curved edge in the groove width direction and the radius of curvature of a convex curved edge in the spiral direction of a thread groove. 3. A screw shaft glossiness evaluation apparatus according to claim 1, wherein a base portion on which said irradiation portion and said light receiving portion are provided, and a screw shaft facing said base portion and supporting said screw shaft. and a bearing portion, wherein the relative positions of the irradiating portion and the light receiving portion provided on the base portion and the screw shaft supported by the screw shaft bearing portion can be adjusted. Equipment for axial gloss evaluation. 4. The apparatus for evaluating screw shaft glossiness according to claim 3, wherein the base portion has a first linear direction as a direction of parallel movement with respect to the screw shaft supported by the screw shaft support portion, and a direction perpendicular to the first linear direction. It is possible to move in the second linear direction as the separation movement direction with respect to the screw shaft supported by the screw shaft support part, and in the third linear direction as the vertical movement direction orthogonal to the first linear direction and the second linear direction. A device for evaluating screw shaft glossiness, wherein a movable portion is provided for adjusting the relative position of the screw shaft supported by the irradiation portion, the light receiving portion, and the screw shaft support portion. . 5. The screw shaft glossiness evaluation apparatus according to claim 4, wherein said movable portion is configured to vertically rotate said base portion. 6. The apparatus for evaluating screw shaft glossiness according to claim 3, wherein the screw shaft support portion is configured to support the screw shaft in a horizontal state, and further, the supported screw shaft 1. An apparatus for evaluating screw shaft glossiness, comprising: a vertical rotation mechanism for vertically rotating a shaft; and a horizontal rotation mechanism for horizontally rotating the supported screw shaft.

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