JPS63176808A - Insert screw for pressing in resin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention involves forming a plurality of spiral thread grooves with different thread heights on the circumferential surface of a round bar material, and press-fitting the thread grooves into a resin plate or the like. use,
The present invention relates to an insert screw for press-fitting a resin, in which the retaining force is directed by the difference in level between the thread grooves.

[Summary of the Invention] The present invention provides a first spiral thread groove having a predetermined width in the axial direction on the circumferential surface of a bar, and a first spiral thread groove having a predetermined width in the axial direction with respect to the first spiral thread groove. A second spiral thread groove having a different height from the thread height of the first spiral thread groove is formed with a predetermined interval between the first and second spiral thread grooves. The second spiral thread groove is used to be screwed into the screw receiving member, and the first spiral thread groove and
In the insert screw for resin press-fitting, which is designed to improve the removal force by utilizing the step between the threads of the second helical thread groove, the thread of the second helical thread groove is The second spiral thread groove is first formed in the same shape as the first spiral thread groove, and then Then, the top of the thread of the second spiral thread groove formed in the same shape as the first spiral thread groove is removed to increase the height of the thread of the second spiral thread groove. By making the height of the first helical thread lower than that of the first helical thread, it is possible to simplify the manufacturing process of this type of screw and to obtain the same extraction effect as when forming a thread of the same shape. I made it.

[Prior Art] As shown in FIGS. 7 to 9, a first spiral thread groove 2 having a predetermined axial width W is formed on the outer peripheral surface of a cylindrical bar I, and With a predetermined distance d between the first helical thread groove 2 and the first helical thread groove 2,
A second spiral thread groove 5 is formed in which the height hl of the thread 3 and the height h2 of the thread 4 are different. It can be mounted by press-fitting into the screw receiving hole of the member, and by screwing the other member into the female thread 6 provided on the inner peripheral surface of the cylindrical bar 1, the other member can be attached to the screw receiving hole. An insert screw 7 for press-fitting a resin that can be used as an anchor for attaching to a member is known (for example, Japanese Patent Publication No. 48-13899).

[Problems to be Solved by the Invention] By the way, in the conventional resin press-fitting insert screw 7 described above, the first spiral thread groove 2 to the thread thread 3 and the second
As shown in Fig. 9, the spiral thread grooves 5 to 4 are of the same type, that is, they have the same shape but different sizes, which causes the following problems. there were.

(1) As mentioned above, due to the nature that the first spiral screw ib ¥2 to thread 3 and the second spiral screw groove 5 to thread 4 are made in the same way, the manufacturing process Generally, as shown in FIG. 10, a first . The first thread groove 2.5 having a different diameter serves as a base for forming the second spiral thread groove 2.5. The second step portions 1a, lb are turned, and then the first step portions 1a, lb are turned. Second step 1a, I
Using a roller die with a step corresponding to the diameter of b, the first. The first .
Since the second spiral thread groove 2.5 is rolled, a complicated manufacturing process is required.

(2) In order to produce without the need for complicated manufacturing processes, it is sufficient to use a so-called 6-axis automatic lathe, but in order to use a 6-axis automatic lathe, it is necessary to The manufacturing of screw 7 using a 6-axis automatic lathe is suitable for mass production because the jigs and tools are expensive, and prototyping and manufacturing take a lot of time. When manufacturing a target quantity in a short period of time, the cost becomes high due to the trial production period, trial production cost, etc.

The present invention has been made for the purpose of solving the above-mentioned conventional problems and providing an insert screw for resin press-fitting that can be easily manufactured without using a general-pulling tool or a special rolling roller.

[Means for solving the problem] A first spiral thread groove is formed on the circumferential surface of the bar, and a predetermined interval is maintained in the axial direction with respect to the first spiral thread groove. In the insert screw for resin press-fitting, the resin press-fitting insert screw is formed with a second helical thread groove having a different height from that of the first helical thread groove in a state in which the second helical thread is The thread of the groove was formed in a shape in which the top of the thread of the first helical thread groove was removed.

[Function] The resin press-fitting insert screw of the present invention is used by being press-fitted into a screw receiving member such as a resin plate in the same manner as the conventional screw described above, but when press-fitting into a screw receiving member such as a resin plate, 1st
When the helical thread groove or thread enters into the screw receiving member while scraping the resin of the screw receiving member, a spring notch is generated due to the elasticity of the resin, and the second spiral thread groove or thread is inserted into the thread receiving member. As the insertion progresses, the screw of the present invention is press-fitted into the screw receiving member. The removal force in the direction opposite to the press-fitting direction is caused by the helix angle of the helical thread groove and the thread of the first helical thread groove, which is generated by removing the top of the thread of the second helical thread groove. The removal force in the press-in direction is ensured by the springback acting on the helical thread groove.

〔Example] Next, the present invention will be explained with reference to FIGS. 1 to 6.

1 to 3 show an insert screw for press-fitting a resin according to a first embodiment of the present invention. In the figure, reference numeral 11 denotes a resin press-fitting insert screw of the present invention, and as shown in FIGS.
The first spiral thread groove 13 is formed with a predetermined distance d in the axial direction from the first spiral thread R13. Thread groove■3
The height h2 of the thread 15 is higher than the height h' of the thread 14 in
The second spiral thread groove I6 has a predetermined width w in the axial direction.
It is formed in 2. Further, the second spiral thread groove 1
As shown in FIG. 3, the thread 15 of No. 6 is formed by removing the top of the thread 14 of the first spiral thread groove 13. A stepped portion 17 is formed between the top portion of the thread 14 of the screw thread 13 and the top portion of the screw thread 14 . Note that 18 is a pilot flange formed at the end of the bar 12 on the side of the first helical screw groove 13; 20 is a ring-shaped recess formed between the second helical screw groove I6 and the first helical screw groove 13; 2I is a cylindrical rod; This is a female thread formed on the inner peripheral surface of the material 12.

Then, when the pilot flange part 18 side is pressed against the opening of the screw receiving hole 22a provided in the resin screw receiving member 22 and pressed while applying high frequency vibration etc., the flange part 18 and the first helical shape Thread groove 13 to thread 14
inserts into the screw receiving hole 22a while scraping the resin of the screw receiving member 22, and then the second spiral thread groove 16 also enters into the screw receiving hole 221, and the insert screw II for press-fitting the resin is inserted into the screw receiving hole. It is now press-fitted into 22a.

The removal force in the opposite direction to the press-in direction is the first one. The helix angle of the second helical thread groove 13, 16 and the thread of the first helical thread groove 13 caused by removing the top of the thread 15 of the second helical thread groove 16. This is ensured by the stepped portion 17 with respect to I4, and the removal force in the press-fitting direction is
．． Secured by a sprink pack acting on the second helical thread groove 13.16, insert screw 1 for plastic press-fitting
1 is firmly inserted into the screw receiving hole 22a of the screw receiving member 22 (
It is attached so that it cannot easily come off).

The resin press-fitting insert screw 11 of the first embodiment has the above-mentioned configuration, and the thread 15 of the second spiral thread groove I6 is connected to the thread 14 of the first spiral thread groove 13. Since it is formed in a shape with the top removed and the stepped portions 17 of these threads 14 and 15 are used to ensure the removal force,
Said 1st. To manufacture the second helical thread groove 13.16, first, the first helical thread i7+¥13 is formed over the entire outer circumferential surface of the bar 12, and then the second helical thread If the top of the thread 14 of the first helical thread groove 13 is removed at the location where the thread groove 6 is to be formed, the first helical thread IRI 3 becomes the second helical thread i+
It becomes 6. If the pilot flange 18 and ring-shaped recess 19, 20 are further turned, the remaining portion becomes the first helical thread groove 16 of a predetermined width, and the screw 11 of the present invention can be obtained. It will become.

4 to 6 show a resin press-fitting insert screw 11 according to a second embodiment of the present invention, and the resin press-fitting insert screw 11 of the second embodiment is the same as the resin press-fitting insert screw 11 of the first embodiment. A thread having a shape in which the top of the thread 15 of the second spiral thread groove 16 is removed is inserted into one end of the second spiral thread groove 16 through a ring-shaped recess 23 having a predetermined width w3. 24, a third spiral thread groove 25 is formed, and the second
A case is shown in which a stepped portion 26 is also formed between the thread 15 of the spiral thread groove 16 and the thread 24 of the third spiral thread groove 25. The other 1T portion is the same as in the first embodiment.

Note that in the embodiment shown in the drawings, the first screw threads have different heights.
The second case where two spiral thread grooves 13 and 16 are formed, and the first case where two spiral thread grooves 13 and 16 are formed. Second. Third three spiral thread grooves 13,1
6.24 is shown, however, the number of spiral thread grooves with different thread heights is not limited to that of the above embodiment, and may be four or more.

[Effects of the Invention] As described above, the present invention forms a first spiral thread groove on the circumferential surface of a bar, and also forms a first spiral thread groove in the axial direction with respect to the first spiral thread groove. In the insert screw for resin press-fitting, the insert screw for resin press-fitting is formed with a second spiral thread groove having a different height from the thread of the first spiral thread groove with a predetermined interval. Since the spiral thread groove thread of the first spiral thread groove has a shape in which the top of the thread of the first spiral thread groove is removed, the following effects can be obtained.

(+) When forming the first spiral thread groove on the circumferential surface of the bar, a thread groove of the same shape as this is formed, and then the top of the thread of the thread groove is removed. A second helical thread groove having a thread height different from that of the first helical thread groove can be formed by a method such that the first helical thread groove is different in height from the first helical thread groove. Sufficient screw removal force can be ensured at the stepped portion of the thread of the second spiral thread groove.

(2) As described in item (1) above, by forming a thread groove having the same shape as the first spiral thread groove and removing the top of the thread of the thread groove, the second spiral thread groove is formed. Since it forms a thread groove in the shape of a shape, there is no need to use a 6-axis automatic lathe I3, cliff cutting tool, or special rolling roller, which is required for conventional screws of this type. Can be lowered.

[Brief explanation of the drawing]

Fig. 1 is a side view of the resin press-fitting insert screw according to the first embodiment of the present invention, Fig. 2 is a cross-sectional view of the same, Fig. 3 is a view taken in the direction of arrow a in Fig. 1, and Fig. 4 is the second embodiment. A side view of an example resin press-fitting insert screw, FIG. 5 is a sectional view of the same, and FIG. 6 is a of FIG. 4.
7 is a side view of the conventional example from 1, FIG. 8 is a cross-sectional view of the same, FIG. 9 is a view taken from direction a in FIG. 7, and FIG. FIG. DESCRIPTION OF SYMBOLS 11... Insert screw for resin press-fitting, 12... Bar material, 13... First spiral thread groove, 14.15... Thread thread, 16... Second spiral thread groove . Figure 3, 11, '@: r Chiang, 'if? (R electric Z of the screw in the row (IJ side view, Figure 4) Figure 5, Figure 6) B?IJQtTifffl Figure 8 Figure 7 d liquid roJ large 7q Figure 9 Conventional L near)

Claims (1)

[Scope of Claims] A first spiral thread groove is formed on the circumferential surface of the bar, and a predetermined interval is left in the axial direction with respect to the first spiral thread groove, The insert screw for resin press-fitting has a second spiral thread groove having a different height from that of the first spiral thread groove, wherein the thread of the second spiral thread groove is different from the thread height of the second spiral thread groove. An insert screw for resin press-fitting, characterized in that it is formed in a shape in which the top of the thread of the first spiral thread groove is removed.