JP2020085638A - Outer diameter measurement unit and method for measuring outer diameter - Google Patents

Abstract

To provide an outer diameter measurement unit which allows a user to quickly and accurately confirm, without skills, the outer diameter of a thin and long measurement target with a round cross section.SOLUTION: An outer diameter measurement unit 1 has a substrate 2 with three holes 11 to 13, for example. The diameter of the hole 12 in the center is equal to the nominal outer diameter Dof a measurement target. The diameter of the hole 11 on the left side is smaller than the nominal outer diameter Dby a predetermined deviation. The diameter of the hole 13 on the right side is larger than the nominal outer diameter Dby a predetermined deviation α. The deviation α is set according to the tolerance. A measurement target is inserted into the holes 11 to 13 and the outer diameter is confirmed.SELECTED DRAWING: Figure 1

Description

The present invention relates to an outer diameter measuring instrument suitable for confirming whether or not an outer diameter of an elongated measuring object having a circular cross section is within a predetermined range, and an outer diameter measuring method using this outer shape measuring instrument.

In a line that manufactures resin extruded products (measurement targets) that have a circular cross section, check whether the outer diameter of the extruded product is within the tolerance range of the pre-specified outer diameter (nominal outer diameter). There is a need to.

In the outer diameter confirmation work of the extruded product, an outer diameter measuring instrument such as a caliper or a micrometer is used to measure the outer diameter of the extruded product while sandwiching the extruded product.
However, when the hardness of the extruded product is low, for example, when the extruded product is made of polyethylene elastomer or EPDM foamed rubber, the outer diameter measuring device causes the extruded product to be narrowed and elastically deformed. In that case, the measurement result is smaller than the actual outer diameter. If too much care is taken not to cause elastic deformation in the extruded product, the outer diameter measuring device will not come into good contact with the extruded product, resulting in a measurement result larger than the actual outer diameter.
Therefore, a skill is required for the measurement work, and even a skilled person has a variation in the measurement result for the same extrusion molded product.

In order to measure the outer diameter of extruded products with high accuracy, it may be possible to use a microscope or an electronic precision outer diameter measuring device, but in that case, it takes time to confirm the outer diameter, and the outer diameter is within the tolerance range. If you continue to produce defective products that are out of order, waste will occur.

The outer diameter measuring device disclosed in Patent Document 1 is formed by forming a slit in a flat plate-shaped substrate. The slit has a wedge shape, and both side edges of the slit are linear. Scales representing the width of the slit are formed on both sides of the slit along the longitudinal direction of the slit. The outer diameter is measured by inserting an elongated measuring object having a circular cross section from the open end of the slit along the slit and reading the scale at the position where the insertion is blocked.

JP, 2004-205474, A

Although the outer diameter measuring device of Patent Document 1 can quickly measure the outer diameter of the measurement target, it is difficult to accurately read the position where the insertion of the measurement target is blocked on the scale. Particularly, in the case of a measuring object having a low rigidity, elastic deformation of the measuring object may occur at the insertion preventing position of the slit, resulting in variation in outer diameter measurement.

The present invention has been made to solve the above problems, in an outer diameter measuring device for measuring the outer diameter of a slender measuring object having a circular cross section, the substrate is formed with a plurality of holes of a perfect circle having different diameters. It is characterized by being
According to the above configuration, it is necessary to learn whether or not the measurement object can be inserted into the plurality of holes, or whether the diameter of the measurement object is within the range of the diameters of the plurality of holes due to the insertion resistance at the time of insertion. It can be confirmed quickly and accurately.

In a preferred aspect, the plurality of holes have a diameter equal to the nominal outer diameter of the measurement target, a hole having a diameter smaller than the nominal outer diameter by a predetermined deviation, and a hole larger than the nominal outer diameter by the deviation. The predetermined deviation including a diameter hole is set in correspondence with the tolerance.
According to the above configuration, it can be accurately confirmed whether or not the measurement target is within the tolerance range of the nominal outer diameter.

In a preferred aspect, the plurality of holes are a hole having a diameter equal to a nominal outer diameter of the measurement target, a pair of holes having an outer diameter obtained by adding and subtracting a first deviation from the nominal outer diameter, and the nominal diameter. A pair of holes having an outer diameter that is added to and subtracted from the outer diameter by a second deviation smaller than the first deviation is included, and the first deviation is set corresponding to the tolerance.
According to the above configuration, it is not only possible to accurately check whether or not the outer diameter of the measurement target is within the tolerance range of the nominal outer diameter, but the outer diameter of the measurement target is within a predetermined range closer to the nominal outer diameter. You can check whether or not.

In a preferred aspect, the plurality of holes include a large number of holes arranged in the order of diameter, and the diameters of the plurality of holes are stepped by equal deviations from a predetermined lower limit outer diameter to a predetermined upper limit outer diameter. Grows larger.
According to the above configuration, it is possible to confirm the outer diameters of a plurality of measurement targets having different nominal outer diameters.

Another aspect of the present invention is an outer diameter measuring method, wherein the measuring object is directed to the hole of the outer diameter measuring device, whether or not it can be inserted, or by checking the insertion resistance at the time of insertion, It is characterized by confirming whether or not the diameter of the measurement target is within the range of the diameter of the hole.

According to the present invention, the diameter of an elongated measuring object having a circular cross section can be confirmed quickly and accurately without requiring any skill.

FIG. 3 is an enlarged plan view of the outer diameter measuring instrument according to the first embodiment of the present invention, showing the difference in diameter slightly exaggerated. It is an enlarged plan view of the outer diameter measuring instrument concerning a 2nd embodiment of the present invention, and shows a difference in diameter a little exaggeratedly. It is a top view of the outer diameter measuring device which concerns on 3rd Embodiment of this invention.

Hereinafter, a first embodiment of the present invention will be described with reference to FIG. The outer diameter measuring instrument 1 is for measuring the outer diameter of an elongated measuring object having a circular cross section. The object to be measured in this embodiment is an extruded product made of synthetic resin, particularly an extruded product having low rigidity and elasticity. Specifically, it is a sealing material made of synthetic rubber such as styrene-butadiene rubber or silicone rubber. The Young's modulus of this sealing material is 0.5 to 10 MPa, the hardness (JIS type A) is 5 to 40 HS, and the tensile strength (room temperature) is about 6 to 20 MPa.

The outer diameter measuring instrument 1 has a rectangular flat plate-shaped substrate 2, and the substrate 2 is formed with three (a plurality of) holes 11, 12, and 13 of perfect circles. The holes 11 to 13 have different diameters, and are aligned in the order of the diameter size.

The diameter of the central hole 12 is equal to the nominal outer diameter D ₀ of the extrudate, the right hole 11 has a diameter (D ₀ −α) of the nominal outer diameter D ₀ minus the deviation α, and The hole 13 has a diameter (D− ₀ +α) obtained by adding the deviation α to the nominal outer diameter D ₀ . The deviation α is equal to or slightly smaller than the tolerance. As a specific example, when the nominal outer diameter D ₀ is 5.50 mm and the deviation α is 0.25 mm, the diameters of the holes 11 to 13 are as follows.
Diameter of hole 11: 5.25 mm
Diameter of hole 12: 5.50 mm
Diameter of hole 13: 5.75 mm

The outer diameter of the extruded product immediately after being molded on the extrusion molding line is confirmed using the outer diameter measuring device 1 having the above configuration. That is, it is confirmed whether the outer diameter of the extruded product is within the intersecting range of the nominal dimension D ₀ . The confirmation work will be described below.

First, the insertion of the extruded product into the hole 12 is tried. If this insertion is impossible or if there is insertion resistance even if it can be inserted (when it is inserted with a diameter reduction due to elastic deformation), it is determined that the outer diameter of the extruded product is larger than the nominal dimension D _0. Then, the insertion into the hole 13 having a larger diameter is tried. If the insertion is impossible or the insertion resistance is large, it is determined that the extrusion molded product is a defective product having a diameter larger than the upper limit of the tolerance range.
When the extrusion-molded product is inserted into the hole 13 without resistance, it is confirmed that the outer diameter D of the extrusion-molded product is within the following range, and the product is judged to be acceptable.
D ₀ <D≦D ₀ +α (1)

When the extruded product can be inserted into the central hole 12 without resistance (including the case where it is inserted with play and the case where it can be inserted without play), the outer diameter of the extruded product is the nominal dimension D ₀ . Equal or less than the nominal dimension D ₀ , then try to insert into hole 11 with smaller diameter. Here, when the extruded product is inserted without play without play, it is determined that the extruded product is a defective product having a diameter smaller than the lower limit of the tolerance range. If the extruded product cannot be inserted into the hole 11 or has insertion resistance, or if it can be inserted without play and without insertion resistance, confirm that the outer diameter D of the extruded product is within the following range and pass. Judge as an item.
D ₀ −α≦D≦D ₀ (2)

As described above, the outer diameter of the extrusion-molded product can be confirmed quickly and accurately without the need for skill, due to the resistance to insertion into the holes 11 to 13.
When the diameter of the extruded product is within the tolerance range and the extruded product is an acceptable product, the operating state of the extrusion molding line is maintained as it is. If the diameter of the extruded product is out of the tolerance range and it is determined that the extruded product is a rejected product, immediately stop the extruded product line and adjust the equipment and molding conditions of the extruded product line. Can be done.
In the first embodiment, the central hole 12 may be omitted and only the holes 11 and 13 may be formed in the substrate 2.

Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, the outer diameter measuring device and the substrate are given the same numbers as in the first embodiment. In this embodiment, the substrate 2 is formed with five holes 21 to 25 each having a perfect circle. These holes 21 to 25 have different diameters and are formed in order from left to right.
The hole 23 in the center has a diameter of the nominal dimension D ₀ , the diameter of the hole 21 at the right end has a diameter (D ₀ −α) obtained by subtracting the first deviation α from the nominal outer diameter D ₀ , and the hole at the left end is 25 has a diameter (D− ₀ +α) obtained by adding the first deviation α to the nominal outer diameter D ₀ . The diameter of the second hole 22 from the right end has a diameter (D ₀ −β) obtained by subtracting the second deviation β from the nominal outer diameter D _0, and the second hole 24 from the left end has a diameter equal to the nominal outer diameter D ₀ . It has a diameter (D− ₀ +β) obtained by adding two deviations β.
The deviation α is equal to or slightly smaller than the tolerance. The second deviation β is smaller than the first deviation α.

As a specific example, when the nominal outer diameter D ₀ is 5.50 mm, the first deviation α is 0.25 mm, and the second deviation β is 0.02 mm, the diameter of each hole is as follows.
Diameter of hole 21: 5.25 mm
Diameter of hole 22: 5,48mm
Diameter of hole 23: 5.50 mm
Hole 24 diameter: 5.52 mm
Diameter of hole 25: 5.75 mm

In the present embodiment, the holes 21, 23, 25 are arranged on the same straight line, and the holes 22, 24 deviate from this straight line, so that the length of the substrate 2 is suppressed. You may arrange on the same straight line.

In the above-mentioned configuration, when the outer diameter of the extruded product coming out of the extrusion molding line is confirmed by the outer diameter measuring device 1, the insertion into the central hole 23 of the extruded product is first tried. If the insertion is impossible or there is insertion resistance, the insertion into the hole 24 having a larger diameter is tried. If the insertion can be made without resistance regardless of the presence or absence of play, it is confirmed that the outer diameter D of the extruded product is within the following range.
D ₀ <D≦D ₀ +β (3)

If the insertion into the hole 24 is impossible or there is insertion resistance, the insertion into the hole 25 having a larger diameter is tried. If the insert can be inserted without resistance regardless of whether or not there is play, it is confirmed that the outer diameter D of the extruded product is within the following range.
D ₀ +β<D≦D ₀ +α (4)
If there is insertion resistance in the hole 25, it is determined that the product is a defective product of D>D ₀ +α.

Contrary to the above, when the extruded product can be inserted into the hole 23 without resistance regardless of whether or not there is any play, the insertion into the hole 22 is tried. If there is insertion resistance in this hole 22 or if there is no play and insertion is possible without resistance, it is confirmed that the outer diameter D of the extruded product is within the following range.
D ₀ −β≦D≦D ₀ (5)

If the extruded product can be inserted into the hole 22 without resistance with play, the insertion into the hole 21 having a smaller diameter is tried. If the insertion is impossible or there is insertion resistance, or if there is no play and there is no resistance, then check that the outer diameter D of the extruded product is within the following range.
D ₀ −α≦D<D ₀ −β (6)
When the extruded product can be inserted without resistance in the hole 21 with no play, it is determined that the extruded product is a defective product of D<D ₀ −α.

In the second embodiment, as in the first embodiment, the holes 21 and 25 can be used to confirm whether the product is a good product within the tolerance range or a defective product outside the tolerance range, and the extrusion molding line can be adjusted, and if necessary. Accordingly, it is confirmed whether or not the diameter D of the extruded product is in the vicinity range (D ₀ −β≦D≦D ₀ +β) of the nominal outer diameter D ₀ , and the extrusion molding line is set so as to be in this vicinity range. You can also fine-tune it.
In the second embodiment, the central hole 23 may be omitted.

Next, a third embodiment of the present invention will be described with reference to FIG. In FIG. 3, the outer diameter measuring device and the substrate are given the same numbers as in the first embodiment. In this embodiment, a large number of, for example, 30 perfect circular holes 30 having different diameters are formed. In FIG. 3, the hole with the smallest diameter is labeled with 30 _MIN, and the hole with the largest diameter is labeled 30 _MAX . The holes 30 are arranged in order from the _smallest diameter hole 30 _MIN to the largest diameter hole 30 _MAX , with the diameter increasing stepwise by an equal deviation.
As a specific example, the diameter of the hole 30 _MIN having the smallest diameter is 4.0 mm, the diameter of the hole 30 _MAX having the largest diameter is 6.9 mm, and the deviation is 0.1 mm.

A scale is further displayed on the substrate 2. The scale 51 on the left side is a scale in units of mm, and the scale 52 on the upper side is a scale in units of 0.1 mm.
A hole 30 of 4.0 mm to 4.9 mm is formed in the first row represented by "4", and a hole 30 of 5.0 mm to 5.9 mm is formed in the second row represented by "5", A hole 30 of 6.0 mm to 6.9 mm is formed in the third row represented by "6".

The outer diameter measuring device 1 of the present embodiment can be used for a plurality of extrusion molded products having different nominal outer diameters. That is, a hole 30 having a diameter equal to the nominal outer diameter of the extruded product, a hole 30 adjacent to this hole 30 smaller by 0.1 mm and a hole 30 larger by 0.1 mm are selected, that is, three holes 30 are selected. , Can be used as in the first embodiment. It is also possible to select the holes 30 having the same nominal outer diameter and two holes 30 adjacent to each other on the left and right, that is, select five holes 30 and use them as in the second embodiment.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. For example, the measurement target may not be an extrusion molded product made of synthetic resin, but may be an injection molded product, for example. It may be made of natural rubber instead of synthetic resin. In the case of synthetic rubber, it may be foamed rubber. The nominal outer diameter D ₀ of the measurement target is not particularly limited, but is preferably about 0.5 to 10 mm.

INDUSTRIAL APPLICABILITY The present invention can be used for confirming the outer diameter of an extruded product made of synthetic resin.

1 outer diameter measuring device 2 substrate 11-13, 21-25, 30 hole

Claims (5)

In an outer diameter measuring device for measuring the outer diameter of a slender measuring object having a circular cross section,
An outer diameter measuring instrument, wherein a plurality of perfect circle holes having different diameters are formed on a substrate. The plurality of holes, a hole having a diameter equal to the nominal outer diameter of the measurement target, a hole having a diameter smaller than the nominal outer diameter by a predetermined deviation, and a hole having a diameter larger than the nominal outer diameter by the deviation. The outer diameter measuring instrument according to claim 1, wherein the predetermined deviation is set corresponding to the tolerance. The plurality of holes are a hole having a diameter equal to the nominal outer diameter of the measurement target, a pair of holes having an outer diameter added and subtracted by a first deviation from the nominal outer diameter, and the nominal outer diameter. 2. A pair of holes having an outer diameter obtained by adding and subtracting only a second deviation smaller than the first deviation, and the first deviation is set corresponding to a tolerance. Outer diameter measuring instrument. The plurality of holes include a large number of holes arranged in the order of the diameter, and the diameters of the plurality of holes gradually increase from the predetermined lower limit outer diameter to the predetermined upper limit outer diameter by equal deviations. The outer diameter measuring instrument according to claim 1, wherein The diameter of the object to be measured is determined by arranging the object to be measured in the hole of the outer diameter measuring instrument according to any one of claims 1 to 5 and checking whether or not the object can be inserted, or the insertion resistance at the time of insertion. A method for measuring an outer diameter, comprising checking whether or not the diameter is within the range of the hole.

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