JPS6234655Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a tapping device for cutting an internal thread into a pre-formed hole in a workpiece such as a metal plate.

Background technology A tap is used for normal female thread machining, and some of this machining is performed automatically on automatic thread tapping machines, but in cases where the shape of the workpiece is complex, etc., a tap is used. It is often done manually one by one. In this type of manual female thread machining, there is a possibility that human error may result in incomplete female thread machining or unfinished products, so special inspection is required in a separate process. .

For example, a socket fitting for a straight tube fluorescent lamp will be explained with reference to FIGS. 1 to 4 as a workpiece to be machined with a female thread. Figure 1 shows an example of a single-lamp lighting fixture, where 1 is the ceiling, and 2 is the lighting fixture body screwed to the ceiling 1. Although not shown, this includes electrical parts such as a ballast that are necessary for the lamp to blink. It will be installed. 3, 3 are socket mounting brackets that are attached to both ends of the instrument body 2, 4, 4 are sockets that are attached to the socket attachment brackets 3, 3, and 5 are socket mounting brackets that are attached to the socket attachment brackets 3, 3 at both ends. This reflector plate 5 has both ends fixed with decorative screws 6, 6.
After installing the straight tube fluorescent lamp 7 in each socket 4, 4.
is assembled. As shown in FIGS. 2 and 3, the socket mounting bracket 3 has a female thread 9 formed at the center of a recess 8 pressed into a central portion, into which a decorative screw 6 is screwed. There is. Since this type of socket mounting bracket 3 has a complicated shape, the female thread 9 is formed by manual thread cutting, and the procedure is as shown in FIG. The tap 11, which can be moved up and down and rotated forward and backward, is inserted into this hole 10 to a predetermined depth while cutting an internal thread by rotating it in the forward direction using a manual handle operation, and then it is rotated in the reverse direction to remove it. It is being done.

However, since the internal thread cutting of the socket mounting bracket 3 is done manually, there may be variations in the insertion length of the tap 11 into the hole 10, resulting in defective products with incorrect internal thread dimensions, or unfinished products due to operator misunderstanding. In some cases, the products were mixed in with other normal processed products. In the former case, the occurrence of defective products may make it difficult or uncertain to screw in the decorative screws 6 when assembling lighting equipment on site.
A particular problem is that the latter unprocessed product is shipped as a product, and in this case, it is completely impossible to assemble the lighting equipment on-site, which significantly impairs the reliability of the product. Therefore, conventionally, a special inspection process is provided to check whether or not the female thread 9 of the socket fitting 3 has been machined. This inspection is very difficult to visually judge and often overlooked, so it is actually done by inserting a threaded rod or inspection gauge, but this has the problem of requiring a lot of time and effort, and improvements are needed. Ta.

DISCLOSURE OF THE INVENTION The present invention satisfies the above-mentioned needs and provides a tap device having a structure that forms a contact mark on the surface of a workpiece at the same time as a female thread cutting process as a mark indicating that a female thread has been cut.

The present invention is characterized in that, as a means for forming the contact marks, a drawing needle that rotates integrally with the tap is attached elastically around the tap. By attaching this line-drawing needle, contact marks are formed on the surface of the workpiece, centering around female threads.The presence or absence of these contact marks is easy to visually confirm, so the presence or absence of female threads can be confirmed by checking this. becomes easier. Furthermore, when manually machining female threads, the insertion length of the tap can be determined by knowing the feel of the drawing needle in contact with the workpiece, thereby making it possible to more uniformly process the dimensions of the female thread.

BEST MODE FOR CARRYING OUT THE INVENTION In FIGS. 5 and 6, 12 is a tap for machining internal threads, 13 is a circular housing concentrically fixed at a fixed position on the outer periphery of the tap 12, and 14 is a housing 1.
A ring-shaped needle mounting plate is housed in the tap 3 and is fitted into the tap 12 concentrically and slidably in the axial direction with respect to the tap 12. Reference numeral 15 denotes a spring member whose upper and lower ends are fixed to the needle mounting plate 14 and the top plate 13a of the housing 13, and supports the needle mounting plate 14 within the housing 13 so as to be movable up and down. 16, 16 is the needle mounting plate 14
These are two line drawing needles whose tips protrude from window holes 17, 17 formed at two places on the bottom plate 13a of the housing 13, and are made of a hard material such as a scribing needle. The two drawing needles 16, 16 have the same size and are arranged on the same circle centered on the tap 12.

For example, when manually forming the female thread 9 of the above-mentioned socket fitting 3 using the above-mentioned tap device, the center hole 10 of the recess 8 of the socket fitting 3 is inserted while rotating the entire tap 12 in the normal direction by operating the handle as in the conventional method. Insert it into. Then, just before the desired female thread 9 is formed, the tips of the drawing needles 16, 16 come into elastic contact with the surface around the recess 8, as shown in FIG. A circular scratch is made to form a circular contact mark 18 as shown in FIG. The worker who is operating the handle knows that the female thread 9 has been machined to the predetermined dimension by the feeling that is transmitted to the hand when the drawing needles 16, 16 hit the area around the recess 8, and after confirming this feeling, presses the tap 12. Rotate it in the opposite direction and remove it from the machined female screw 9. By doing this, the internal thread 9 is always formed within normal dimensions, and when the internal thread 9 is formed, contact marks 18 are also necessarily formed.

By forming the contact traces 18 to the extent that they can be easily confirmed visually, the presence or absence of the female thread 9 can be inspected by easily visual inspection of the contact traces 18, and therefore a special inspection tool such as an inspection gauge is not required. No special inspection process is required, and inspection can be carried out during normal post-processes such as finishing processes such as cleaning processes or product packaging processes. Also, oil is sometimes used when machining the female thread and then cleaned, or the socket mounting bracket 3 is sometimes painted and finished, but there is no need to worry about the contact marks 18 disappearing due to such cleaning or painting. .

Note that the present invention is not limited to the above-mentioned embodiments; in particular, it is also possible to use one or more drawing needles, or to form a plurality of concentric contact marks with a plurality of drawing needles. These are selected depending on the workpiece. In addition, the workpiece is not limited to socket mounting brackets,
Depending on the workpiece, it is also possible to automatically machine a female thread using the tapping device according to the present invention.

As described above, according to the present invention, the presence or absence of female thread machining can be easily confirmed by visual judgment of contact traces.
Special tools and processes for inspecting the presence of female threads are no longer required, resulting in labor savings and improved work efficiency. Also, by checking the contact between the drawing needle and the workpiece, it is possible to prevent variations in the accuracy of female thread machining.

[Brief explanation of the drawing]

Figure 1 is an exploded side view of the lighting fixture, Figures 2 and 3 are perspective views of the socket mounting bracket in Figure 1, and A
- An enlarged sectional view taken along line A; FIG. 4 is a partial side view for explaining female thread machining using a conventional tap; FIGS. 5 and 6 are perspective views and essential parts of an embodiment of the present invention; The cross-sectional view, FIGS. 7 and 8 are a cross-sectional view of a workpiece and a partially perspective view of a processed workpiece for explaining internal thread machining using the tapping device according to the present invention. 3... Workpiece (socket mounting bracket), 9...
Female thread, 12...Tap, 16...Line drawing needle, 18
...Contact marks.

Claims (1)

[Scope of utility model registration request] A drawing needle is elastically attached to the circumference of the tap for machining female threads, and rotates integrally with the tap to form contact traces in the form of ruled lines on the surface of the workpiece during machining of female threads. tap device.