JPH0446169Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a measuring instrument, and more specifically, to an improvement of a measuring instrument for precisely measuring the pitch error of a screw.

[Conventional technology]

As a means of measuring the pitch of the screw, conventional methods such as a projector and a pitch chart are used when high accuracy is not required. In addition, when measuring items that require high precision such as lead screws, the object to be measured (lead screw) 5 is fixed and the measuring device (digital dial gauge) 2 is used as shown in Figure 2.
A method has been adopted in which the needle 7 attached to the opening/closing arm 11 attached to the dial spindle 8 of the machine is sequentially engaged with the thread groove, and the displacement length is sequentially measured with a length measuring device 2 and printed out.

[Problems to be solved by the invention] In the method shown in FIG. 2, when the needle engages with the pitch groove, the needle engagement position varies in the pitch groove direction (screw circumferential direction). The looseness of the needle and the groove affected the measured values, resulting in large variations in the repeatedly measured values as shown in FIG. 3, making it unsuitable for high-precision measurements such as measurements for evaluating the accuracy of processing machines.

In addition, it took about 15 minutes to measure one piece, including the setup time for measurement, making it unsuitable for use in mass production.

Further, due to the structure of the set of the object to be measured and the structure of the opening/closing arm, the object to be measured is not versatile and can only be used for two or three types of lead screws.

[Means for solving problems]

In order to solve the above problems, the present invention provides the first
As shown in the figure, first, in order to stabilize the engagement between the pitch groove and the needle, the object to be measured was set on the V-groove, the needle was set on a rotating support, and the needle was pressed against the thread groove by a spring.

Next, when the object to be measured is rotated on the V-groove, the object to be measured moves in the axial direction due to the engagement between the pitch groove and the needle, and the object to be measured is rotated at a constant rate by the measuring claw of the divided index plate. The structure is such that the length of movement can be measured each time by the displacement of the spindle of a length measuring device that is pressed against the other end of the object to be measured.

[Operation] The work to be measured is set in the V groove of the workpiece support, and the semi-fixedly supported (rotatingly supported) guide needle is pressed against the workpiece pitch groove by a spring, thereby eliminating play between the pitch groove and the guide needle. When the sticking is eliminated and the object to be measured is rotated, the object moves in the axial direction due to the engagement between the guide needle and the pitch groove, and the displacement of its tip is measured with a length measuring device (digital gauge), and the results are printed out. By doing this, you can know the pitch of the object to be measured and the pitch error.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a length measuring device 2 and a needle support 3 are fixedly arranged on a base 1 of the measuring device.
The object support stand 4 has a V-groove on its upper surface, and is semi-fixedly arranged so that its shape can be selected depending on the type of object to be measured.

One end of the object to be measured 5 is set on the rotary dividing index plate 6, and the other end of the object to be measured is set to a length measuring device (digital gauge).
It is set on the V-groove of the measurement object support stand 4 so as to be in contact with the dial spindle 7 of No. 2.

The needle 7 is fixed to a rotational fulcrum on the needle support 3, mounted on a needle lever 9 pressed by a spring 12, and pressed into engagement with the pitch groove of the object to be measured.

In the present invention, when the divided index plate is rotated, the object to be measured 5 moves in the axial direction due to the engagement between the pitch groove and the needle 7, and the displacement of the tip is measured by the length measuring device (digital gauge) 2. measured.

The divisional index plate 6 is equipped with a rotation angle scale, and by rotating the object to be measured every fixed rotation using the rotation angle determining pawl 10 and measuring the displacement, the pitch and pitch of the object to be measured can be determined. The error can be precisely measured.

[Effect of idea]

Regarding the problems of accuracy, measurement time, and generality as mentioned above in [Problems to be solved by the invention], the measuring device of the present invention has more than twice the accuracy and 1 times the measurement time. /5.In terms of versatility, it is possible to measure many types of objects by simply replacing the setting member, which facilitates process control and quality control of mass-produced screws. I was able to do that.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an overview of the screw pitch measuring device of the present invention, and FIG. 2 is a side view showing an overview of a conventional screw pitch measuring device. FIG. 3 is an example data diagram showing the dispersion of measured values when the screw pitch was measured five times using a conventional measuring device. 1...Base, 2...Length measuring device (digital gauge) 3...Needle support, 4...Measurement object support stand,
5...Measurement object, 6...Divided index plate, 7...Needle, 8...Dial spindle, 9...Needle lever, 10...Degree claw, 11...Opening/closing arm, 12...Spring.

Claims (1)

[Scope of utility model registration request] In a screw pitch measuring device, one end of the object to be measured (screw) is fixed to a split index plate, set in a groove on the object support base, and a semi-fixed needle is press-engaged with the thread groove of the object to be measured. By rotating the divided index plate, the object to be measured moves in the axial direction on the groove, and the measuring shaft of the measuring instrument is pressed against the other end of the measured object, and the displacement of this measuring axis and the divided index plate are A screw pitch measuring device characterized by measuring the pitch error based on the rotation angle.