JPH09178404A - Screw depth measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the effective depth of a screw hole with high precision and easily by measuring travel amount of a slide body supported slidably in a direction parallel with a shaft core of a screw plug gage. SOLUTION: After confirming the agreement of zero scale of measurement scale with zero scale of auxiliary scale in a condition in which a lower end face of a screw plug 6 of a screw plug gage 2 is flush with a lower end face of a gage main body 3, the lower end face of the gage main body 3 is brought into contact with a port fringe of a screw hole 1 to be measured which is formed on a workpiece, and a screw plug 6 is screw-fitted in the screw hole 1 by turning an operation knob 9. The travel amount of the gage 2 can be visually measured based on measurement scale and auxiliary scale when a slide body 4 moves in the axial direction in correspondence to screw-fitting of the screw plug 6 and screw-fitting of the screw plug 6 is completed. At this time, since the slide body 4 is positioned on a front face of the main body 3 and moves only in the axial direction from the start of screw-fitting of the screw plug 6 to completion, it is possible for a person who measures to measure screw depth easily if he is positioned on the measurement scale side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw depth measuring tool used for measuring the effective screw depth of a screw hole.

[0002]

2. Description of the Related Art Generally, when forming a screw hole (for example, a blind screw hole) for screwing a bolt or the like, it is inspected whether or not the formed screw hole conforms to an appropriate standard. It includes a procedure for further processing and modification based on the results.

In the above inspection, the effective depth and effective diameter of the screw hole are to be measured, and in general,
The depth is measured by inserting it into the screw hole using a caliper.

However, due to the presence of the non-threaded portion having a V-shaped cross section formed at the bottom when forming the screw hole, the depth of the entire screw hole and the depth of the screw portion in the screw hole (that is, the effective depth) match. Not not. Therefore, when measuring the screw hole depth with a caliper, etc., it is impossible to directly measure the effective depth, so the effective depth must be estimated by subtracting the screw non-forming part from the measurement result. High effective thread depth could not be measured.

As a method for checking the effective depth of the screw hole, there is a method in which a plug is screwed into the screw hole and the screwing completion position is compared with the standard upper limit or lower limit position. It can only be used for the target screw hole, cannot be used for general purposes, and cannot measure the effective thread depth with high accuracy.

As a solution to the above-mentioned problems, there has been proposed one in which the moving amount of a screw rod screwed into a screw hole to be measured is measured by a scale (for example,
(See JP-A-6-185903).

[0007]

However, in the above-mentioned known example, when the screw rod is screwed into the screw hole to be measured, the scale display portion also rotates, so that the screw rod is completely screwed. The position of the scale display portion at that time is not specified. Therefore, it becomes difficult to always match the position of the eyes of the measurer with the scale display portion, and the measurer must change the position and read the scale.

The present invention has been made in view of the above points, and by enabling the scale reading from a constant position at all times, the effective depth of the screw hole can be measured with high accuracy and easily. The purpose is to do.

[0009]

In the basic configuration of the present invention, as means for solving the above problems, a screw plug gauge having a screw plug to be screwed into a screw hole to be measured,
A gauge main body that rotatably supports the screw plug gauge, and slidably supported with respect to the gauge main body in a direction parallel to the axis of the screw plug gauge, and with movement of the screw plug gauge in the axis direction. It comprises a moving slide body and a scale which is fixed to the gauge body and has a measuring scale for measuring the amount of movement of the slide body, so that the scale can always be read from a fixed position.

In the basic configuration of the present invention, when a ring groove is formed in the screw plug gauge and an engaging body which is fitted into the slide body so as not to rotate together with the ring groove is integrally formed, a ring is formed. This is preferable in that the slide body can be moved in the axial direction when the plug cage is screwed, with a simple structure in which the engagement body is loosely fitted in the groove.

Further, when a vernier scale is formed on the slide body, it is preferable in that the accuracy of measuring the amount of movement of the slide body is significantly improved.

Further, it is preferable that the screw plug can be attached to and detached from the screw plug gauge, because the screw plug can be easily replaced (ie, replaced with a new one or a different kind).

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, this screw depth measuring tool is used for measuring the effective screw depth of the screw hole 1 to be measured. A screw plug gauge 2 having a screw plug 6 to be screwed, and a gauge body 3 rotatably supporting the screw plug gauge 2.
A slide body (4) slidably supported with respect to the gauge body (3) in a direction parallel to the axis of the screw plug gauge (2) and moving with movement of the screw plug gauge (2) in the axis direction; The scale 5 is fixed to the main body 3 and has a scale 7 for measuring the amount of movement of the slide body 4.

The screw plug gauge 2 includes a rod portion 8 which is rotatably and axially slidably fitted in a gauge body 3 formed of a vertically long cylindrical body, and an operating knob 9 which is connected to an upper end of the rod portion 8. And a screw plug 6 that can be attached to and detached from the lower end of the rod portion 8.

The screw plug 6 has a taper shaft 11 fitted into a taper hole 10 formed at the lower end of the rod portion 8. The taper shaft 11 and the taper hole 10 are perpendicular to the axial direction. Pin 12 that penetrates from different directions
Is connected to the rod portion 8 via. That is,
By attaching and detaching the taper pin 12, the screw plug 6 is attached and detached with respect to the screw plug gauge 2. By doing so, when the screw portion of the screw plug 6 is worn due to repeated measurement work of screwing the screw plug 6 into the measured screw hole 1 to measure the effective screw hole depth, it is easy to obtain a new one. It can be replaced, and the type of the screw plug 6 can be changed according to the screw hole 1 to be measured. In addition,
By inserting the taper shaft 11 of the screw plug 6 into the taper hole 10 of the screw plug gauge 2 and penetrating the taper pin 12, the screw plug 6 and the screw plug gauge 2 can be attached and detached. It is extremely easy to put on and take off.

A ring groove 13 is formed at an intermediate position of the rod portion 8 of the screw plug gauge 2 for loosely fitting an engaging body 21, which will be described later.

Bosses 14 and 15 are integrally formed on both front ends of the gauge body 3 in the axial direction, and the scale 5 is fixed to the front surfaces of the bosses 14 and 15 with screws 16. ing. In addition, between the scale 5 and the bosses 14 and 15, shims 17 and 18 for ensuring the axial posture (in other words, vertical posture) of the scale 5 are provided.
Are interposed respectively.

The slide body 4 holds a pair of both sides of the scale 5 and slides in the axial direction (in other words, the vertical direction), and a pair of sliders 19 and 19.
9 and 19 and a connecting member 20 for connecting the intermediate portions thereof, and the inner surface of the connecting member 20 rotates together with the ring groove 13 formed in the rod portion 8 of the screw plug gauge 2. An engagement body 21 that is impossible to loosely fit is provided integrally with the projection. A guide hole 22 for guiding the engaging body 21 in the axial direction is formed in the gauge body 3. Further, a vernier scale 23 is formed on one side of the sliders 19, 19.

In this screw depth measuring tool,
When the lower end surface of the gauge body 3 and the lower end surface of the screw plug 6 are flush with each other, 0 scale on the measurement scale 7 of the scale 5 and 0 scale on the vernier scale 23 of the slider 19 are set.
It is adjusted so that it matches the scale.

A procedure for measuring the screw depth (in other words, the effective depth of the screw) using the screw depth measuring tool having the above structure will be described.

Screw plug 6 in screw plug gauge 2
After confirming that the 0 scale of the measuring scale 7 and the 0 scale of the vernier scale 23 are aligned with the lower end surface of the gauge main body 3 flush with the lower end surface of the gauge body 3, it is formed on the work W. The lower end surface of the gauge main body 3 is brought into contact with the rim of the measured screw hole 1 and the operation knob 9 is rotated to screw the screw plug 6 into the measured screw hole 1. Then, the slide body 4 moves in the axial direction corresponding to the screwing of the screw plug 6, and when the screwing of the screw plug 6 is completed, the screw scale is determined from the scale of the measuring scale 7 and the scale of the vernier scale 23. The amount of movement of the gauge 2 (in other words, the effective depth of the screw hole 1) can be visually measured. At this time, since the slide body 4 is located on the front surface of the gauge body 3 and moves only in the axial direction from the start of screwing the screw plug 6 to the completion thereof, the measurer should be positioned on the measurement scale 7 side. If so, the screw depth can be easily measured.

If the accuracy of the screw plug 6 is improved, this screw depth measuring instrument can measure the effective depth of the screw and can simultaneously perform the inspection of the screw accuracy (for example, the effective diameter inspection of the screw).

[0024]

According to the present invention, a screw plug in a screw plug gauge is screwed into a screw hole to be measured, and the effective depth of the screw is determined by the amount of movement of a slide body that moves axially in accordance with the screwing. Since the measurement is performed, the effective depth of the screw can be directly measured by the operator's visual observation from a specific direction, which has an excellent effect that highly accurate measurement can be performed easily and reliably.

Further, when a ring groove is formed in the screw plug gauge and an engaging body which is loosely fitted in the ring groove so as not to rotate together is integrally formed with the slide body, the engaging body for the ring groove is formed. With the simple structure of loose fitting, the slide body can be moved in the axial direction when the plug cage is screwed, which greatly contributes to simplification of the structure.

Further, when the vernier scale is formed on the slide body, the accuracy of measuring the amount of movement of the slide body is greatly improved, and the accuracy of measuring the effective depth of the screw is further improved.

Further, when the screw plug can be attached to and detached from the screw plug gauge, the screw plug can be easily exchanged (that is, exchanged with a new one or a different type) and can be used semipermanently. Moreover, versatility is also improved.

[Brief description of the drawings]

FIG. 1 is a front view of a screw depth measuring tool according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a screw depth measuring tool according to an embodiment of the present invention.

[Explanation of symbols]

1 is a screw hole to be measured, 2 is a screw plug gauge, 3 is a gauge body, 4 is a slide body, 5 is a scale, 6 is a screw plug, 7 is a measuring scale, 13 is a ring groove, 21 is an engaging body, 2
3 is a vernier scale.

Claims (4)

[Claims] 1. A screw plug gauge having a screw plug screwed into a screw hole to be measured, a gauge main body rotatably supporting the screw plug gauge, and a shaft core of the screw plug gauge parallel to the gauge main body. A slide body that is slidably supported in various directions and that moves with the axial movement of the screw plug gauge, and a scale that is fixed to the gauge body and that has a measuring scale that measures the amount of movement of the slide body. A screw depth measuring tool characterized by being provided. 2. A ring groove is formed in the screw plug gauge, and an engaging body is formed integrally with the slide body so as to be loosely fitted in the ring groove so as not to rotate together. The screw measuring tool according to claim 1, wherein: 3. The screw measuring tool according to claim 1, wherein a vernier scale is formed on the slide body. 4. The screw measuring tool according to claim 1, wherein the screw plug is attachable to and detachable from the screw plug gauge.