JP2001183103A - Measurement auxiliary tool for vernier calipers and measurement auxiliary tool for micrometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable accurately and quickly positioning and holding an object to be measured at a position capable of length measurement. SOLUTION: A positioning holding member 31 is installed which comes into contact with the outside surface of the object to be measured and positions and holds the object between a fixed jaw 12 and a movable jaw 16 of a vernier calipers 10 in such a manner that the object is in parallel with the lengthwise direction center line x of a main scale 11. A positioning holding member 51 is installed which comes into contact with the outside surface of the object and positions and holds the object between an anvil 22 and a spindle 23 in such a manner that the object is in parallel with the axial line 23x of the spindle 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring aid for calipers used with calipers so that an object to be measured can be measured quickly and accurately. In addition, the present invention relates to a measurement aid for a micrometer used with a micrometer so that an object to be measured can be measured quickly and accurately.

[0002]

2. Description of the Related Art Vernier calipers and micrometers are frequently used as measuring instruments for measuring the length in production sites and the like.

FIG. 9 shows a conventional construction of a caliper 10.

In the drawing, reference numeral 11 denotes a main scale, and 15 denotes a vernier scale. The main scale 11 has a fixed jaw 12, and a scale is engraved along a longitudinal center line 11x. The vernier scale 15 has a movable jaw 16 facing the fixed jaw 12, and is slidably provided along a longitudinal center line 11 x of the main scale 11.

[0005] With the object M to be measured held in one hand, the vernier 15 of the caliper 10 is slid with the other hand, and the object M is sandwiched between the fixed jaw 12 and the movable jaw 16. The length of M is to be measured. Generally, the minimum reading dimension is 1/20 mm. In many cases, the DUT M is a straight round bar whose both end surfaces are cut off so as to be orthogonal to the longitudinal axis.

On the other hand, as shown in FIG. 10, a micrometer 20 has a frame 21 having an anvil 22 at one end.
And a spindle 23 which is screwed to the other end of the frame 21 and is displaced in the direction of the axis 23x with the screwing rotation, holding the object M in one hand and turning the ratchet stop 24 with the other hand. For example, the length of the object to be measured M is sandwiched between the anvil 22 and the spindle 23 to measure the length. Generally, the minimum reading dimension is 1/100 mm.

[0007]

When measuring the length of the long measuring object M with a small end face area using the caliper 10 and the micrometer 20 described above, the two-dot chain line in FIGS. 9 and 10 is used. As shown by, the measurement is performed in a state where the object to be measured M is oblique, and the length cannot be accurately measured.

For example, if the diameter d is 3 mm and the processing length dimension L
As shown in FIG. 11, when the DUT a is measured with a vernier caliper 10 and a micrometer 20 as shown in FIG.

Lm = cosα × √ (d ² + La ² )

= Cos α × 60.07 From the above equation, the measurement dimension Lm is maximum (60.07 mm) when the angle α is 0, and decreases as the angle α increases. Therefore, a measurement error occurs.
This measurement error increases as the measured object M becomes longer.

In order to prevent such a measurement error from occurring, the positional relationship between the object M and the main scale 11 (or the spindle 23) must be carefully determined so that the object M is not tilted. A decision must be made, but this can take a great deal of time, even for a skilled person.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a caliper measurement aid which can quickly position and hold an object to be measured at a position where the length can be accurately measured. It is another object of the present invention to provide a measurement auxiliary tool for a micrometer capable of quickly positioning and holding an object to be measured at a position where the length can be accurately measured.

[0013]

According to a first aspect of the present invention, a main scale having a fixed jaw and a movable jaw opposed to the fixed jaw are provided slidably along a longitudinal center line of the main scale. A vernier caliper measurement auxiliary tool used with a vernier caliper and a vernier caliper capable of measuring the length of the measured object with the fixed jaw and the movable jaw sandwiching the measured object, the outer surface of the measured object And a positioning and holding means for positioning and holding the object to be measured between the fixed jaw and the movable jaw so as to be parallel to the longitudinal center line of the main scale.

In this case, the object to be measured is positioned and held by the positioning and holding means between the fixed jaw and the movable jaw so as to be parallel to the longitudinal center line of the main scale. Therefore, the measured object can be quickly positioned and held at a position where the length can be accurately measured.

According to a second aspect of the present invention, the positioning and holding means is detachably attached to the main scale portion between the fixed jaw and the movable jaw, and comes into contact with the outer surface of the object to be measured, so that the object to be measured is A caliper measurement auxiliary tool formed by a positioning and holding member having a holding portion for positioning and holding an object between the fixed jaw and the movable jaw so as to be parallel to a longitudinal center line of the main scale.

In this case, the object to be measured is positioned and held between the fixed jaw and the movable jaw by the holding portion of the positioning and holding member so as to be parallel to the longitudinal center line of the main scale. When measuring the length of an object to be measured such as a short block having a large end surface area, the positioning and holding member can be removed from the main scale. Therefore, the same operation and effect as those of the first aspect can be obtained, and the length can be measured in an optimum state according to the shape of the measured object.

According to a third aspect of the present invention, the holding portion of the positioning holding member is such that the center of one end face of the object to be measured abuts the measurement surface of the fixed jaw and the center of the other end face measures the movable jaw. A first holding portion for positioning and holding the object to be measured at a position in contact with the surface, and a portion excluding a center portion of one end surface of the object to be measured contacting the measurement surface of the fixed jaw and a center portion of the other end surface. And a second holding portion for positioning and holding the object to be measured at a position where the portion excluding the portion comes into contact with the measurement surface of the movable jaw.

According to this invention, when there is a projection (bitch) generated during cutting, for example, at the center of the one end face and / or the other end face of the measured object, the length including the projection and the length not including the projection are accurately determined. And the height of the protrusion can be quickly obtained from the measurement result. Therefore, the same operation and effect as those of the invention described in claim 1 or 2 can be obtained, and the length of the protrusion (botto) at the center of one end face and / or the other end face of the measured object can be quickly and accurately determined. Can be sought.

According to a fourth aspect of the present invention, there is provided a caliper measurement auxiliary tool wherein the positioning and holding member is formed so as to be capable of changing a length of a holding portion of the main holder in the longitudinal direction of the main scale.

According to this invention, the objects to be measured having different lengths can be quickly positioned and held at positions where the length can be accurately measured.

According to a fifth aspect of the present invention, there is provided a frame having an anvil at one end, and a spindle screwed to the other end of the frame and displaced in the axial direction with the screwing rotation,
A measurement aid for a micrometer used with a micrometer capable of measuring the length of an object to be measured with an object to be measured sandwiched between an anvil and a spindle, the measuring aid being in contact with the outer surface of the object to be measured. Positioning and holding means for positioning and holding the object to be measured between the anvil and the spindle so as to be parallel to the axis of the spindle is provided.

In this case, the object to be measured is positioned and held between the anvil and the spindle by the positioning and holding means so as to be parallel to the axis of the spindle. Therefore, the measured object can be quickly positioned and held at a position where the length can be accurately measured.

According to a sixth aspect of the present invention, the positioning and holding means is detachably mounted on the frame and comes into contact with the outer surface of the object to be measured, and the object to be measured is moved between the anvil and the spindle. Is a measurement aid for a micrometer formed from a positioning and holding member having a holding portion for positioning and holding so as to be parallel to the axis of the micrometer.

In this case, the object to be measured is positioned and held between the anvil and the spindle by the holding portion of the positioning and holding member so as to be parallel to the axis of the spindle. In addition, for example, when measuring the length of an object to be measured such as a short block having a large end surface area, the positioning and holding member can be removed from the main scale. Therefore, the same operation and effect as in the case of the invention described in claim 5 can be obtained, and the length can be measured in an optimum state according to the shape of the measured object.

According to a seventh aspect of the present invention, the holding portion of the positioning holding member is arranged such that a central portion of one end surface of the object to be measured is in contact with a measuring surface of the anvil and a central portion of the other end surface is in contact with a measuring surface of the spindle. A first holding portion for positioning and holding the object to be measured at a contact position, and a portion excluding a center portion of one end surface of the object abutting on a measurement surface of the anvil and excluding a center portion of the other end surface. A second holding unit for positioning and holding the object to be measured at a position where the part comes into contact with the measurement surface of the spindle;

In the case of the present invention, when there is a projection (bitch) generated at the time of cutting at the center of one end face and / or the other end face of the measured object, the length including the projection and the length not including the projection are defined. Accurate measurement can be performed, and the length of the protrusion can be quickly obtained from the measurement result. Therefore,
In addition to providing the same operation and effect as in the case of the invention according to claim 5 or 6, the length of a protrusion (botto) at the center of one end face and / or the other end face of the measured object is quickly and accurately obtained. be able to.

An eighth aspect of the present invention is a measurement auxiliary tool for a micrometer, wherein the positioning and holding member is formed so as to be able to change the holding range length of the holding portion in the spindle axial direction.

In the case of this invention, the objects to be measured having different lengths can be quickly positioned and held at positions where the length can be accurately measured.

Embodiments of the present invention will be described below with reference to the drawings. (First embodiment)

The caliper measurement aid 30 according to the present invention comprises:
As shown in FIGS. 1 to 3, the measuring object M comes into contact with the outer side surface Ms of the measuring object M and is fixed between the fixed jaw 12 and the movable jaw 16 of the vernier caliper 10.
And a positioning and holding means (31) for positioning and holding so as to be in parallel with.

The caliper 10 to which the caliper measurement aid 30 is applied is the same as the conventional example (FIG. 9).
The description is omitted.

More specifically, the positioning and holding means comprises a main scale 1 between the fixed jaw 12 and the movable jaw 16 of the caliper 10.
One portion is detachably attached using a screw or the like, and comes into contact with the outer side surface Ms of the object M, and the object M is held between the fixed jaw 12 and the movable jaw 16 in the longitudinal center line of the main scale 11. Holder 3 for positioning and holding so as to be parallel to 11x
5 is formed from the positioning and holding member 31 having the number 5.

An object M whose length is to be measured using the caliper measurement aid 30 according to the present invention is a straight round bar (having a small diameter d and a large processing length La with respect to the diameter d). For example, d = 3 mm, La = 60 mm).

Here, there is an object to be measured M which has a projection (so-called boch) formed at the center of the end face (Mu, Mv) at the time of cutting, and the length of the projection is less than an allowable value. If so, it may be considered a pass.

Therefore, in this embodiment, the positioning and holding member 3 is provided so that the length of the protrusion (bitch) b at the center of the end surface (Mu, Mv) of the DUT M can be obtained quickly and accurately.
As shown in FIGS. 2 and 3, the center of one end surface Mu of the DUT abuts on the measurement surface 12s of the fixed jaw 12, and the center of the other end surface Mv is the movable jaw 16 as shown in FIGS. The object to be measured M is located at a position where the
First holding portion (35a, 36a) for positioning and holding
And a portion excluding the central portion of the one end surface Mu of the DUT abuts on the measurement surface 12s of the fixed jaw 12 and the other end surface M
The portion excluding the center of v is the measurement surface 16 of the movable jaw 16.
a second holding portion (35b, 36b) for positioning and holding the device under test M at a position where the device to be measured M contacts.

More specifically [0035] The first holding portion of the positioning holding member 31 includes a holding step portion 35a for the object to be measured M ₁ relatively large diameter d, for the object to be measured M ₂ diameter d is smaller And the holding step 36a. Further, the second holding portion of the positioning holding member 31 is provided with the object to be measured M _1.
A holding step portion 35b of use, and is formed from a holding step portion 36b for the measurement object M _2.

In the vernier caliper measurement auxiliary tool 30 having such a configuration, the object to be measured M is held between the fixed jaw 12 and the movable jaw 16 of the caliper 10 by the holding portion 35 of the positioning holding member 31 in the longitudinal center line of the main scale 11. It is positioned and held so as to be parallel to 11x.

[0037] For example, the in the case of measuring the length of the measured object M ₁ is the measurement of the fixed jaw 12 in a state where the pressed against the holding step portion of the outer surface Ms of the DUT M ₁ (35a or 35b) The movable jaw 16 is sandwiched between the surface 12s and the measurement surface 16s of the movable jaw 16.

[0038] The state in the case of measuring the object _{M 1} is having projections b in the central portion of the end surface (Mu, Mv), pressed against the outer surface Ms of the measuring object _{M 1} in the holding step portion 35a The measurement object M ₁ is fixed to the measurement surface 12 of the fixed jaw 12 with
s and the measuring surface 16s of the movable jaw 16 to measure the length including the protrusion b. Next, the outer surface of the object to be measured _{M 1} M
s is pressed against the holding step 35b and the fixed jaw 1 is
2 and the measurement surface 16s of the movable jaw 16 to measure the length excluding the protrusion b. From these two measurement results, the length of the protrusion b can be quickly and accurately obtained.

Further, when measuring the length of the measuring object M ₂ also does not include the length and the projection b of the projection b by using the above-described case in the same manner as holding step portion (36a or 36b) length Can be determined quickly and accurately.

When measuring the length of an object to be measured such as a short block having a large end surface area, the positioning and holding member 31 is removed from the main scale 11. Thus, the length of a short object can be measured quickly and accurately.

Further, as shown in FIG. 4, the positioning and holding member 3
1 may be formed so that the length Lt of the main measurement longitudinal direction of the holding portion 35 can be changed.

That is, the positioning holding member 31 is connected to the holding portion 35 [first and first holding portions (35a, 36a,
35b, 36b)], the one positioning holding piece 31 slidably mounted on the main scale 11 between the fixed jaw 12 and the movable jaw 16 along the longitudinal center line 11x.
A and the other positioning holding piece 31B may be used. With this configuration, it is possible to change the length of the range in which the DUT M can be held (the length Lt of the protection range in the longitudinal direction of the main scale), so that the DUT M having various lengths can be accurately measured. Positioning can be held quickly.

In the above embodiment, the case where the positioning and holding member 31 is detachably mounted on the main scale 11 of the caliper 10 has been described. You may. As shown in FIG. 5, a measuring table 40 capable of locking the caliper 10 is provided.
The positioning and holding means may be formed by providing a positioning and holding part 31E having a function equivalent to that of the positioning and holding member 31 having the holding part 35. (Second embodiment)

The second embodiment is shown in FIGS.

The micrometer measurement aid 50 according to the second embodiment contacts the outer surface Ms of the object M and places the object M between the anvil 22 and the spindle 23 along the axis 23x of the spindle 23. And a positioning and holding means (51) for positioning and holding so as to be parallel to the above.

Note that the measuring aid 50 for the present micrometer is used.
Is applied to a conventional micrometer 20 (FIG. 10).
Therefore, the description is omitted.

More specifically, the positioning and holding means is detachably mounted on the frame 21 of the micrometer 20 by using a screw 59 or the like, and comes into contact with the outer side surface Ms of the object M so that the object M can be anviled. Positioning holding member 5 having a holding portion 55 for positioning and holding between the spindle 22 and the spindle 23 so as to be parallel to the axis 23x of the spindle 23
1 is formed.

In this embodiment, the positioning holding member 51
Positioning protrusions (52A, 52A) for determining the mounting position with respect to the frame 21 at both ends of the main body 51f.
B) is formed. This positioning projection (52)
A, 52B) such that the positioning and holding members 5 are in contact with the outer peripheral lower surface of the anvil 22 and the outer peripheral lower surface of the spindle 23.
When the screw 1 is screwed to the frame 21, the holding portion 55 is formed so as to be parallel to the axis 23 x of the spindle 23.

The object to be measured M whose length is measured using the micrometer measuring aid 50 according to the present invention is:
The end face (Mu, Mv) is a straight round bar having a small diameter and a processing length larger than the diameter.

Here, the object to be measured M has an end face (M
u, Mv) have a projection b generated during the cutting process at the center, but if the length of the projection b is less than an allowable value, it may be regarded as an acceptable product.

Therefore, in this embodiment, the holding portion 55 of the positioning holding member 51 is provided so that the length of the protrusion b at the center of the end surface (Mu, Mv) of the DUT can be quickly and accurately obtained. A first position of the object M is positioned and held at a position where the center of the one end surface Mu of the measurement object M contacts the measurement surface 22s of the anvil 22 and the center of the other end surface Mv contacts the measurement surface 23s of the spindle 23. Holding part (55a,
56a), the portion of the DUT M excluding the central portion of the one end surface Mu contacts the measurement surface 22s of the anvil 22 and the portion excluding the central portion of the other end surface Mv contacts the measurement surface 23s of the spindle 23. A second holding portion (55b, 56b) for positioning and holding the DUT at the position.

More specifically, the positioning holding member 51
As shown in FIG. 7, the first holding portion 55 has a relatively large diameter.
Large DUT M₁Holding step 55a and small diameter
Measuring object M₂And a holding step 56a for
ing. Also, a second holding portion of the positioning holding member 51
Is the object to be measured M₁Holding step 55b and the DUT M
₂And a holding step 56b.

In the micrometer measurement aid 50 having such a configuration, the DUT M is positioned and held between the anvil 22 and the spindle 23 by the positioning and holding member 51 so as to be parallel to the axis 23x of the spindle 23. You.

[0054] For example, when measuring the length of the measured object _{M 1} is the anvil 22 in a state where the pressed against the outer surface Ms of the holding step portion of the object to be measured _{M 1} (55a or 56b)
And the measurement surface 23s of the spindle 23.

[0055] The state in the case of measuring the object _{M 1} is pressed against the outer surface Ms of the DUT _{M 1} in the holding step portion 55a of the central portion having a projection b of the end face (Mu, Mv) Then, the length including the protrusion b is measured by sandwiching between the measurement surface 22s of the anvil 22 and the measurement surface 23s of the spindle 23. Next, the holding step portion 56 of the outer surface Ms of the workpiece _{M 1}
In a state pressed against the measurement surface 22b, the measurement surface 22s of the anvil 22 and the measurement surface 23s of the spindle 23 are sandwiched between the measurement surface 22s and the length excluding the protrusion b is measured. From these two measurement results, the length of the protrusion b can be quickly and accurately obtained.

[0056] Also, when measuring the length of the object M _2, the above-described case in the same manner as holding step portion (56a or 5
By using 6b), the length of the protrusion b and the length not including the protrusion b can be quickly and accurately obtained.

When measuring the length of an object to be measured such as a short block having a large end surface area, the positioning holding member 51 is removed from the frame 21. Thus, the length of a short object can be measured quickly and accurately.

As shown in FIG. 8, the positioning and holding member 51 is attached to the main portion of the holding portion 55 so that the object to be measured M having various lengths can be quickly positioned and held at a position where the length can be accurately measured. The longitudinal holding range length Lt may be formed so as to be changeable.

That is, the positioning holding member 51 is connected to the holding portion 55 [first and second holding portions (55a, 56
a, 55b, 56b)], and may be constituted by one positioning holding piece 51A and the other positioning holding piece 51B slidable along the axis 23x of the spindle 23 between the anvil 22 and the spindle 23. With such a configuration, it is possible to quickly position and hold the object to be measured M having various lengths at a position where the length can be accurately measured.

[0060]

According to the first aspect of the present invention, the measuring object is brought into contact with the outer surface of the measuring object so that the measuring object is positioned between the fixed jaw and the movable jaw so as to be parallel to the longitudinal center line of the main scale. Since the positioning and holding means for positioning and holding is provided, the object to be measured can be quickly positioned and held at a position where the length can be accurately measured.

According to the invention of claim 2, the positioning and holding means is detachably mounted on the main scale portion between the fixed jaw and the movable jaw and comes into contact with the outer surface of the object to be measured. 2. A positioning and holding member having a holding portion for positioning and holding an object to be measured between the fixed jaw and the movable jaw so as to be parallel to a longitudinal center line of the main scale. In addition to the effects similar to those of the invention, the length can be measured in an optimum state according to the shape of the object to be measured.

According to the third aspect of the present invention, the holding portion of the positioning holding member is such that the center of one end face of the measured object is in contact with the measurement surface of the fixed jaw and the center of the other end face is the movable jaw. A first holding portion for positioning and holding the object to be measured at a position in contact with the measurement surface of the fixed jaw, and a portion excluding a central portion of one end surface of the object to be measured comes into contact with the measurement surface of the fixed jaw and the other end surface The same effect as in the case of the invention according to claim 1 or 2, since a portion excluding a central portion is constituted by a second holding portion for positioning and holding the object to be measured at a position where it contacts the measurement surface of the movable jaw. In addition to the above, the height of the protrusion (botto) at the center of the one end face and / or the other end face of the measured object can be quickly and accurately obtained.

According to the fourth aspect of the present invention, since the positioning and holding member is formed so as to be capable of changing the length of the holding section in the main measurement longitudinal direction, it is possible to accurately measure objects having various lengths. Positioning can be quickly maintained at a position where length can be measured.

According to the fifth aspect of the present invention, the positioning and holding means is provided between the anvil and the spindle so as to be in contact with the outer surface of the measured object and to position and hold the measured object so as to be parallel to the axis of the spindle. Therefore, the object can be quickly positioned and held at a position where the length can be accurately measured.

According to the invention of claim 6, the positioning and holding means is detachably mounted on the frame and comes into contact with the outer surface of the object to be measured, and the object to be measured is moved between the anvil and the spindle. Since it is formed from a positioning and holding member having a holding portion for positioning and holding so as to be parallel to the axis of the spindle, the same effect as that of the invention according to claim 5 can be obtained, and the shape of the object to be measured can be reduced. The length can be measured in an optimal state accordingly.

According to the seventh aspect of the present invention, the holding portion of the positioning holding member is such that the center of one end face of the object to be measured is in contact with the measurement surface of the anvil and the center of the other end face is the measurement of the spindle. A first holding portion for positioning and holding the object to be measured at a position in contact with the surface, and a portion excluding a central portion of one end surface of the object to be measured contacting the measurement surface of the anvil and a central portion of the other end surface. Since the removed portion comprises the second holding portion for positioning and holding the object to be measured at a position where it comes into contact with the measurement surface of the spindle, the same effect as that of the invention according to claim 5 or 6 can be obtained. In addition, the length of a protrusion (bitch) at the center of one end face and / or the other end face of the measured object can be quickly and accurately determined.

According to the eighth aspect of the present invention, since the positioning and holding member is formed so that the length of the holding range of the holding portion in the spindle axial direction can be changed, objects to be measured having different lengths can be accurately measured. It can be quickly positioned and held at a position where it can be measured.

[Brief description of the drawings]

FIG. 1 is a diagram for describing an embodiment of the present invention.

FIG. 2 is also a cross-sectional view for explaining a holding portion of a positioning holding member.

FIG. 3 is a transverse sectional view for explaining a first holding portion and a second holding portion of the positioning holding member.

FIG. 4 is a view for explaining a pair of positioning and holding pieces constituting the positioning and holding member.

FIG. 5 is a diagram for explaining a modified example.

FIG. 6 is a diagram for explaining a second embodiment of the present invention.

FIG. 7 is a cross-sectional view for explaining a holding portion of the positioning holding member.

FIG. 8 is a view for explaining a pair of positioning and holding pieces constituting the positioning and holding member.

FIG. 9 is a diagram for explaining calipers.

FIG. 10 is a diagram illustrating a micrometer.

FIG. 11 is a view for explaining a problem in the case where an object to be measured having a small end face area and a relatively long length is measured.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Caliper 11 Main scale 12 Fixed jaw 16 Movable jaw 20 Micrometer 21 Frame 22 Anvil 23 Spindle 30 Caliper measurement auxiliary tool 31 Positioning and holding member 35 Holding section 50 Micrometer measurement auxiliary tool 51 Positioning and holding member 55 Holding section

Claims (8)

[Claims] 1. A fixed jaw having a fixed jaw and a movable jaw having a movable jaw opposed to the fixed jaw and slidably provided along a longitudinal center line of the main jaw. And a caliper measurement auxiliary tool used together with a vernier caliper capable of measuring the length of the measured object with the measured object interposed therebetween, wherein the fixing jaw contacts the outer surface of the measured object and fixes the measured object to a fixed jaw. A measurement auxiliary tool for a caliper, comprising positioning and holding means for positioning and holding the movable jaw so as to be parallel to a longitudinal center line of the main scale. 2. The positioning and holding means is detachably attached to the main scale portion between the fixed jaw and the movable jaw, and comes into contact with an outer surface of the object to be measured, and fixes the object to the fixed jaw. The caliper measurement assisting tool according to claim 1, wherein the measuring jaw is formed of a positioning and holding member having a holding portion for positioning and holding the main jaw so as to be parallel to a longitudinal center line of the main scale. 3. The position of the holding portion of the positioning holding member, in which the center of one end face of the object to be measured contacts the measurement surface of the fixed jaw and the center of the other end face contacts the measurement surface of the movable jaw. A first holding portion for positioning and holding the object to be measured, and a portion excluding the center of one end face of the object to be contacted with the measurement surface of the fixed jaw and excluding the center of the other end face. 3. The caliper measurement assisting tool according to claim 2, further comprising a second holding portion for positioning and holding the object to be measured at a position where the object to be measured comes into contact with the measurement surface of the movable jaw. 4. The caliper measurement assisting tool according to claim 2, wherein the positioning and holding member is formed so as to be capable of changing a length of a holding portion of the main holder in a longitudinal direction of the main scale. 5. A frame having an anvil at one end,
A spindle that is screwed to the other end of the frame and that is displaced in the axial direction with the screwing rotation, the length of the object to be measured can be measured by sandwiching the object to be measured between the anvil and the spindle. A measurement aid for a micrometer used together with a micrometer, the positioning aid being in contact with an outer surface of an object to be measured and positioned between an anvil and a spindle so as to be parallel to an axis of the spindle. A measurement auxiliary tool for a micrometer, comprising a holding means. 6. The positioning and holding means is detachably mounted on the frame and is in contact with the outer surface of the object to be measured. The object to be measured is located between the anvil and the spindle in parallel with the axis of the spindle. 6. The measurement aid for a micrometer according to claim 5, wherein the measurement assisting tool is formed from a positioning holding member having a holding portion for positioning and holding. 7. The holding portion of the positioning holding member is located at a position where a central portion of one end surface of the object to be measured contacts the measurement surface of the anvil and a central portion of the other end surface contacts the measurement surface of the spindle. A first holding unit for positioning and holding the object to be measured, and a part excluding a center part of one end face of the object abutting on a measurement surface of the anvil and a part excluding a center part of the other end face of the spindle. 7. The measurement auxiliary tool for a micrometer according to claim 6, further comprising a second holding portion for positioning and holding the object to be measured at a position in contact with the measurement surface. 8. The micrometer measurement aid according to claim 6, wherein the positioning and holding member is formed so as to be able to change a holding range length of the holding portion in a spindle axial direction.