JP3432036B2 - Measuring device for screw diameter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw diameter measuring device capable of accurately measuring the crest or trough diameter of a female screw or a male screw provided at an end of a pipe. . 2. Description of the Related Art In recent years, as a sewer pipe for underground burial, a female screw 11a is provided at one end of a pipe body 1 made of a synthetic resin such as hard vinyl chloride resin as shown in a half sectional view in FIG. At the same time, a propulsion pipe provided with a male screw 11b at the other end is used, and a buried pipe for screwing a male screw 11b of the other pipe 1 to a female screw 11a of the other pipe 1 and then propelling it into the ground. Is being done. However, since the tube 1 made of synthetic resin is easily deformed, a female screw 11a is provided at the end of the tube.
When the male screw 11b is provided, a screw conforming to the standard may not be formed. For this reason, there is a case where the screw fitting is too tight to perform connection at the time of piping construction at the site, and there is a problem that the pipe is detached at the connection portion because the screw fitting is too loose. Therefore, the thread diameter and the valley diameter are measured when the pipe is shipped from the factory or when the pipe is constructed at the site. However, in the conventional measuring method using a caliper or the like, the thread diameter is measured. Sometimes it was not possible to measure accurately. In other words, there is a problem that the root diameter of the screw in a state perpendicular to the axis cannot be accurately measured because the screw thread is displaced by half a pitch in the axial direction when it makes a half turn. SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and provides a thread diameter measuring device capable of simply and accurately measuring the thread diameter and the root diameter of a screw regardless of the type of a female screw or a male screw. is there. SUMMARY OF THE INVENTION The present invention relates to an apparatus for measuring the diameter of a ridge or a valley of a female screw or a male screw provided at an end of a synthetic resin tube, and comprising a metal cylinder. At the end of the body, there is provided a screw to be screwed with the screw, and a holder provided with a slit extending in the axial direction from the end at an opposite position passing through the axis of the screw, approaches and separates in parallel. A measuring instrument provided with a contact at the tip of a pair of slide rods with a female screw of the tube or a half pitch of the female screw. When measuring the crest or trough diameter of a female screw or a male screw provided at the end of a synthetic resin tube, when a metal retainer is screwed into the end of the tube, the tube is inserted. Is corrected to a perfect circle even if the end of the is deformed flat. Therefore, when the slide rod of the measuring instrument is moved toward and away from the slit, and each contact is inserted into the corresponding slit, the contact is located at two opposed positions passing through the axis of the tube. Further, the contact provided at the tip of each slide rod surely comes into contact with the ridge or valley of the female screw or male screw of the tube, so that the ridge or valley diameter of the screw can be measured accurately. An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a partial cross-sectional view of a holder showing one embodiment of the present invention, FIG. 2 is a front view of a measuring instrument showing one embodiment of the present invention, and FIG. 3 is a cross-sectional view illustrating a procedure for measuring a screw diameter. . Reference numeral 1 in the drawing denotes a tube made of a synthetic resin such as hard vinyl chloride resin. The tube 1 is provided with a square female screw 11a at one end and a female screw 11a at the other end. A square male screw 11b to be screwed is provided. 2 is a holder and 3 is a measuring instrument. The holder 2 is a cylindrical body 21 made of a metal such as cast iron.
Is provided with a male screw 22 which is screwed with the female screw 11a of the tubular body 1 at the end thereof, and a slit 23 is provided in the screw portion at a position dividing the circumference into four equal parts from the end in the axial direction. Have been. Then, a pair of opposed slits 2 passing through the axis
The inner portion of each of the reference numerals 3 and 23 extends to the crest or the trough of the male screw 22. Although FIG. 1 illustrates an example in which four slits 23 passing through the axis are provided, the slits 23 may be provided at least at two opposing locations passing through the axis. On the other hand, the measuring instrument 3 has a pair of slide rods 32.
The base portions 33a and 33b of the a and 32b are slidably engaged with the main body portion 31 so that the respective slide rods 32a and 32b can approach and separate in a parallel state. At the ends of the respective slide rods 32a, 32b, contacts 34, 34 are provided so as to protrude in opposite directions opposite to each other.
4 and the other contact 34 are provided in a state of being shifted by a half pitch of the pitch P of the female screw 11a of the tube body 1. The bases 33a, 33b of the slide rods 32a, 32b have fixed clamps 3 attached to the main body 31.
The slide clamps 32 a and 32 b can be fixed to the main body 31 by the fixing clamp 331. Moreover, a finger hook 332 for sliding the slide rod 32b is provided on the base 33b of the one slide rod 32b. When the thumb is hooked on the finger hook 332 and the slide rod 32b is slid, each slide rod 32b is slid. The distance between the tips of the contacts 34, 34 provided at the ends of 32a, 32b
3 is digitally displayed. Next, a procedure for measuring the thread diameter of the internal thread 11a of the tube 1 using this measuring device will be described. First, the holder 2 is screwed into the female screw 11a of the tubular body 1 and inserted into the holder 2 with the gap between the slide rods 32a and 32b narrowed as shown by the dashed line in FIG. Therefore, as shown by the solid line, the respective contacts 34, 34 are inserted into the opposite slits 23, 23 passing through the shaft center, and are brought into contact with the ridges or valleys of the female screw 11a, thereby forming the screw thread diameter or Measure the valley diameter. At the time of this measuring operation, even if the end of the synthetic resin tube 1 is deformed in a flat shape, it is corrected to a perfect circle by the metal tube 2. The contacts are located at two opposing positions passing through the axis of the tube 1, and the respective slide rods 3
Since the contact 34 provided at the tip of 2a, 32b surely comes into contact with the ridges or valleys of the female screw 11a of the tube 1, the ridge diameter or valley diameter of the screw can be accurately measured. In the above embodiment, the apparatus for measuring the diameter of the ridge or the valley of the female screw 11a provided at the end of the synthetic resin tube 1 has been described. When measuring the screw diameter of the male screw 11b provided in the portion, a screw 22 that is screwed with the male screw 11b is provided at the end of the metal cylindrical body 21, and the opposite position passing through the axis of the screw portion. And a holder 2 provided with a slit 23 extending in the axial direction from the end. Then, the measuring device 3 attaches the contacts 34, 3 to the ends of the respective slide rods 32a, 32b.
4 is provided so as to protrude in the opposite direction, and the measurement is performed using one in which one contact 34 and the other contact 34 are displaced by a half pitch of the pitch P of the male screw 11a of the tubular body 1. . As described in detail above, the use of the measuring device of the present invention makes it possible to use the measuring device of the present invention in a position perpendicular to the axis at an opposing position passing through the axis of the tube regardless of the type of the internal thread or the external thread. The thread diameter and valley diameter can be measured easily and accurately.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial sectional view of a holder showing one embodiment of the present invention. FIG. 2 is a front view showing a measuring instrument of the present invention. FIG. 3 is a cross-sectional view illustrating a procedure for measuring a screw diameter according to the present invention. FIG. 4 is a half sectional view showing a connection state of a propulsion pipe. [Description of Signs] 1 Tube 11a Female thread 11b Male thread 2 Holder 21 Metal cylinder 22 Screw 23 Slit 3 Measuring instrument 31 Main parts 32a, 32b Slide rods 33a, 33b Base 34 Contact

Claims (1)

(57) [Claim 1] An apparatus for measuring the diameter of a female screw (11a) or a male screw (11b) provided at the end of a synthetic resin pipe (1). And a metal cylinder (21)
A screw (22) for screwing with the screws (11a, 11b) is provided at an end of the holder, and a slit (23) extending in the axial direction from the end is provided at an opposite position passing through the axis of the screw. The pipe (1) is attached to the tip of a pair of slide rods (32a, 32b) approaching and separating in parallel with the tool (2).
A measuring device (3) provided with a contact (34) shifted by a half pitch of the female screw (11a) or the male screw (11b).