JPH08278101A - Length measurement standard - Google Patents

Abstract

PURPOSE: To inspect the accuracy of a measuring instrument over the wide range of types and measurements. CONSTITUTION: A plate 2 standing on a base 1 has an upper side formed like a staircase and the upper surface 3 of each step of the staircase is used as a height measurement plane. In addition, a pair of right and left horizontal distance measurement planes 5 and 6 are formed at sections falling from each step and at the opposite side of the plate 2. Recesses 7 and 8 are formed on the lower surfaces of the planes 5 and 6, thereby keeping the shape thereof like projections right and left. The bottoms of the recesses 7 and 8 are also finished as horizontal measurement planes. Also, the lowest step has a series of steps A slightly different from each other in height.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a length reference device for inspecting the accuracy of length measuring devices such as a micrometer and a height gauge.

[0002]

2. Description of the Related Art A block gauge (Johansson block) has been often used as a length reference device used for precision inspection of a micrometer or the like. However, if there are many types of measuring instruments to be checked and the measuring ranges of the same type of measuring instruments are different, it takes a lot of time and effort to check the accuracy of each of them using a block gauge.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a length reference device which can inspect the accuracy of a wide variety of measuring instruments having a wide measuring range.

[0004]

SUMMARY OF THE INVENTION The length standard of the present invention comprises a plate that stands on a base. The upper part of the plate is formed in a staircase shape, and each step of the staircase serves as a height measurement surface based on the lower surface of the base. A pair of left and right horizontal distance measuring surfaces are formed on the opposite side of the plate and the falling portion from each step. Each horizontal distance measuring surface projects in the left-right direction.

On at least one step surface of the stairs, a series of steps having different heights can be formed for measuring dial gauges.

[0006]

Embodiments of the present invention will be described with reference to the drawings. The plate 2 is placed upright on the base 1. Both base and plate are made of steel. The plate 2 has an upper side formed in a step shape, and the upper surface 3 of each step of the step is
Is the height measurement surface. H _{1 to} H ₄ are reference dimensions from the bottom surface of the base to each measurement surface 3.

A pair of left and right horizontal distance measuring surfaces 5 and 6 are formed on the falling portion from each step and on the opposite side of the plate. Recesses 7 and 8 are formed on the lower side of the measurement surfaces 5 and 6 so that the horizontal distance measurement surfaces 5 and 6 are projected in the left-right direction. M _{1 to} M ₅ are reference dimensions between the horizontal distance measuring surfaces 5 and 6. The bottoms of the recesses 7 and 8 are also finished as horizontal distance measuring surfaces. N _{1 to} N ₅ are reference dimensions between the left and right recesses.

As shown in detail in FIG. 3, a series of step portions A having slightly different heights are formed in the lowermost step. The steps D ₁ , D ₂ , D ₃ , D ₄ and T ₁ , T ₂ , T ₃ to the respective steps are standard dimensions with the central step 9 as the base point.

Reference dimensions H _{1 to} H ₄ , M _{1 to} M ₅ , N _{1 to} N ₅ , D ₁ to
D ₄ and T _{1 to} T ₃ are measured in advance using a high precision measuring instrument. Explaining the method of use, the outer micrometer selects _one of the reference dimensions M _{1 to} M ₅ that corresponds to the measurement range, actually measures it, and obtains the difference from the reference dimension that has been accurately measured in advance. When the instrumental difference is obtained in this way, the anvil and the spindle of the micrometer are applied to the centers of the measurement surfaces 5 and 6 (position a in FIG. 4). If the anvil and the spindle are brought into contact with the ends of the measuring surfaces 5 and 6 instead of the centers as shown in b, c, d and e of FIG.
The parallelism of the tip surface of the spindle can also be checked. In FIG. 3, the state in which the anvil and the spindle are applied in the d state is shown by a chain line.

The caliper is similar to the case of the micrometer.
The accuracy may be checked by measuring the reference dimensions M _{1 to} M ₅ . However, since there is a risk of scratching the measurement surfaces 5 and 6 that have been finished with high precision for the micrometer, the standard dimensions of N _{1 to} N ₅ are measured to determine the instrumental error. Accuracy inspection of a height gauge, use any of the standard dimensions of H ₁ to H _4. Dial gauge, combined the zero point at the base point 9, sequentially measures the level difference D ₁ to D _4, obtaining a wide range bound accuracy. Subsequently, the return error is obtained by returning from D _{4 to} D ₁ to the base point 9. The lever type dial gauge performs the same measurement using steps T1 to T3.

[0011]

According to the length reference device of the present invention, the upper part of the plate is formed in a step shape, and each step of the step is a height measurement surface with the lower surface of the base as a reference. A pair of left and right horizontal distance measuring surfaces are formed on the opposite side of the falling portion and the plate, and it is possible to easily and quickly inspect the accuracy of three types of measuring instruments, that is, a micrometer, a caliper, and a height gauge. This has the effect of reducing the number of steps required for accuracy inspection. Further, since each horizontal distance measuring surface projects in the left-right direction, the parallelism of the micrometer can be checked by bringing the anvil and the spindle of the micrometer into contact with the end of the measuring surface instead of the center.

If a series of steps having different heights are formed on the upper surface of at least one step of the stairs, the accuracy of the dial gauge can also be inspected.

[Brief description of drawings]

FIG. 1 is a perspective view of a length standard.

FIG. 2 is a front view of a length standard.

FIG. 3 is an enlarged view of part A of FIG.

FIG. 4 is a left side view of the length standard.

[Explanation of symbols]

 1 Base 2 Plate 3 Height Measuring Surface 5 Horizontal Distance Measuring Surface 6 Horizontal Distance Measuring Surface A Step

Claims (2)

[Claims] 1. A base (1) and a plate (2) standing on the base (1), and an upper part of the plate is formed in a staircase shape, and each step of the staircase is a height measurement surface based on a lower surface of the base. (3), a pair of left and right horizontal distance measuring surfaces (5, 6) are formed on the falling part from each step and on the opposite side of the plate. A length reference device characterized in that it protrudes into the. 2. The length standard according to claim 1, wherein a series of stepped portions (A) having different heights are formed on the upper surface of at least one step of the stairs.