JPH01105009A - Wheel nut-bolt for automobile and screw forming method thereof - Google Patents

Abstract

PURPOSE: To reduce the number of stocks, simplify the confirm operation with respect to thread pitch and prevent the waste of parts by threading two kinds of threads on one nut or bolt. CONSTITUTION: A wheel nut body 1 has the shape of a cap nut with an uneven or hexagonal upper portion. A hole 2 has an opening in the center of the lower portion. A thread forming surface 8 which is the internal peripheral surface of the hole 2 is threaded when the wheel nut body 1 is fixed by a suitable fixture. The threading operation is conducted by a tap 5 of the M12 Standard of a 1.5 mm thread pitch in the hole 2. Then the tap mounted on a threading device is substituted by a tap 5a of the M12 Standard of a 1.25 mm thread pitch for threading in the same manner. The threading start by the tap 5a is set to be just identical to the threading start position of the above-mentioned thread groove 3 of 1.5 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to wheel nuts and bolts used for mounting automobile wheels and a method for forming threads thereof.

(Prior Art) As is well known, the wheels of this type of automobile are usually mounted by screwing and fixing the wheel portion of the wheel to the wheel hub on the vehicle body using wheel nuts and bolts.

By the way, the threads of the wheel nuts and bolts are generally determined by the internal standards of the automobile manufacturer. Specifically, some manufacturers set the thread pitch of M12 and MIO to 1.5 m, while other manufacturers set the thread pitch of M12 and MIO to 1.5 m. However, conventional wheel pads and bolts are simply machined screws with one type of thread pitch.

In other words, in the past, for example, even if the nominal thread diameter of a wheel nut was M12, both types with thread pitches of 1.5 Tsuru and 1.25W1 were manufactured and prepared separately. is the reality.

(Problem to be Solved by the Invention) However, as in the prior art, one wheel nut can only accommodate bolts with one type of thread pitch. Or you will have to prepare bolts. As a result, dealers, etc. will inevitably have to stock a large number of wheel nuts or bolts, which will place an extremely heavy economic burden on purchasing and stocking these parts, and will also result in waste. It was causing problems.

In particular, this type of wheel nuts and bolts for automobiles require at least 4 or 5 pieces for each wheel, and a total of 32 to 40 pieces are required to prepare two types of these for each car valley. In view of this, the above-mentioned problem became even more remarkable.

Additionally, in the past, when repairing or replacing wheels, workers had to check the thread pitch of the bolts installed on the vehicle in advance, and then select and use wheel nuts with the corresponding thread pitch. However, checking the screw pitch, which has been set to exact dimensions, requires much more care than checking the nominal diameter of the screw, which is extremely troublesome when replacing wheels, etc. .

Furthermore, if there is an error in measuring the thread pitch, the wheel nut prepared accordingly may become unusable, resulting in an extremely inflexible usability. It was.

Therefore, the present invention makes it possible to use one type of wheel nut or bolt regardless of which of the two types of thread pitch the bolt or nut screw used for attaching the wheel of an automobile is, thereby increasing the stock quantity. The purpose of this is to reduce the number of screws, to omit the work of checking the screw pitch, to prevent wastage of parts due to errors in checking the screw pitch, and to expand the flexibility of use.

(Means for solving the problem) The present invention provides for - wheel nuts or bolts,
This device is designed to solve the above-mentioned conventional problems by carving two types of screws with different pitches so as not to interfere with the screwing operation.

That is, the gist of the structure of the wheel nut/bolt of the present invention is that two types of thread grooves with different pitches are compounded and threaded on the thread forming surface of the wheel nut body or the bolt body, and the two types of thread grooves are Both thread cutting start positions are at the same point.

In addition, the gist of the configuration of the method for forming threads of wheel nuts and bolts of the present invention is that after a single thread groove is carved on the thread forming surface of a wheel nut body or a bolt body, a thread groove with a pitch different from that of the thread groove is formed. There is a method in which the threads are carved from the same thread cutting start position on the same thread forming surface on which the thread grooves are threaded.

(Function) Therefore, in a wheel nut or bolt having the above structure, no matter which of the two screw standards the screw of the bolt or nut to be screwed with is used, Either one of the two types of thread grooves in the corresponding nut body or bolt body of the present invention will be securely screwed together.

In addition, when screwing a wheel nut body or a bolt body having two types of thread grooves to a bolt or a nut having one type of thread, 1. If the common thread cutting start position of the two types of thread grooves matches the formation start position of the thread to be screwed, for example, the thread groove on the side of the two types of thread grooves that does not match the pitch of the threads. There is no possibility that the threads will bite into the threads, and the thread grooves on the side that match the thread pitch will be screwed together smoothly.

Furthermore, in the method for forming threads of wheel nuts and bolts characterized by the above configuration, thread grooves with two different pitches can be formed, and the thread cutting start positions of both thread grooves coincide, and the present invention Threads of wheel nuts and bolts can be formed properly.

(Example) Examples of the present invention will be described below.

First, to explain the thread forming process of the wheel nut according to this embodiment, the wheel nut main body 1 shown in FIG. It has an uneven shape or a hexagonal shape as possible, and a hole 2 is opened in the center of the lower surface.

Then, with the wheel nut main body 1 fixed using a suitable jig or the like, a screw is threaded into the thread forming surface 8 as the inner circumferential surface of the hole 2. This threading work is performed using hydraulic pressure. This is done by inserting an M12 standard tap 5 with a thread pitch of 1.5 m into the hole 2, as shown in FIG. As a result, one type of thread groove 3 is threaded on the thread forming surface 8.

Next, cut the tap attached to the thread cutting device with a thread pitch of 1.
Replace it with a 25m M12 standard tap 5a, and thread a screw using the same method as above, but at this time, the tap 5a
The rotational phase and height position of the tap are set so that the start of thread cutting by exactly coincides with the start position of thread cutting of the thread groove 3 having a pitch of 1.5+1 m.

As a result, two types of thread grooves 3, 3a with the same nominal thread diameter and different pitches are formed on the same thread forming surface 8, and these combined thread grooves 3, 3a are shown in FIG. As shown in b), each pitch PI, h is 1.5m and 1.25, respectively.
Therefore, the cross-sectional shape of the thread groove and the thread has a non-uniform triangular shape due to the difference in pitch dimension. In addition, the two types of screw grooves 3.3a are shown in the same figure (
As shown in b), the respective thread cutting start positions M and Ma match.

The wheel nut formed as described above is used by being screwed onto the stud bolt 4 previously provided on the wheel hub 6 for mounting the wheel 7 as shown in FIG. As mentioned above, when the nominal diameter is M12, the thread pitch is either 1.5 mm or 1.25 mm for domestically produced cars.

Since the wheel nut is provided with a thread groove 3.3a corresponding to both pitches, the thread pitches PI and P of the bolt 4 are adjusted as shown in FIGS. 3(a) and 3(b).
Appropriate screw engagement can be achieved regardless of whether t is 1.5 m or 1.25 fl.

Moreover, the thread cutting start position M of the two thread grooves 3.3a
, Ma are the same, so if you match these thread cutting start positions with the thread start positions of the bolt 4, for example, the wheel nut can be adjusted to the 1+ and - threads of a bolt with a pitch of 1.25 m. There is no need to dig into the thread groove of the 1.5 screw on the side, and the 1.2 screw on the wheel nut side
This allows the screw groove on the 5mm side to be screwed smoothly.

In addition, as a result of making a prototype nut similar to the above and testing the strength of the screw, the applicant found that even if two types of screws are combined and threaded on the same surface, a strength that satisfies the JIS standard can be obtained. It was confirmed that it could be put to practical use.

In the above embodiments, the case where the present invention is applied to a wheel nut has been described, but the present invention is by no means limited to this, and can be applied to the other bolt side as well. That is, as shown in FIG. 5, two types of screw grooves 3 are formed on the thread forming surface 8a as the outer peripheral surface of the bolt body 1a.
, 3a are also included in the technical scope of the present invention. In this bolt, as shown in the same figure (b), the nut 1 has one type of thread by using two types of thread grooves 3.3a, respectively.
It has a flexible effect (can be used for
Just contrary to FIG. 4, it is most suitable for mounting a wheel by fixing a nut to the wheel hub of the vehicle and screwing a separately prepared bolt into the nut.

Further, in the above embodiment, an M12 screw is used as an example, but the present invention is not limited thereto, and the specific screw size and diameter can be changed as desired.

If the target is a foreign car, etc., inch screws, width screws, etc. may be used instead of metric screws. Furthermore,
The specific shape of the thread groove in the present invention is not limited to a triangular shape, and can also be applied as a tapered thread or the like in addition to a parallel thread.

In short, the wheel nut/bolt according to the present invention only needs to have thread grooves of two different pitches formed in combination on the same thread forming surface. Therefore, the specific screw pinch may be arbitrarily selected, and the specific value does not matter.

Further, the thread forming method according to the present invention is not limited to the order in which the thread grooves on the larger pitch side are first threaded and then the thread grooves on the smaller pitch side are threaded as in the above embodiment, but the thread forming method according to the present invention is not limited to the order in which the thread grooves on the side with a larger pitch are first threaded and then the thread grooves on the smaller pitch side are threaded. There is no problem even if there is one, and there is no problem with the specific device 9 used for the screw engraving work.

However, in the present invention, the design of the specific configuration such as the shape and material of each part can be changed within the intended scope of the present invention.

(Effects of the Invention) As described above, the present invention has two types of thread grooves with different pitches carved on a common thread forming surface in combination, so that the bolt or nut to be threaded can be It has become possible to properly screw the screw in any of the two types of screw pitches.

As a result, according to the present invention, it is no longer necessary to constantly prepare two types of wheel nuts and bolts with different thread pitches as in the past, and the stock quantity of these can be halved, resulting in a significant reduction in economic burden. In addition, during screwing work, there is no need to constantly check the thread pitch on the bolt or nut side to be screwed, making it extremely easy to select wheel nuts and bolts, providing flexibility in use and making it easy to attach to automobile wheels. This has resulted in a special effect in that work efficiency can be improved.

In particular, in the present invention, the thread cutting start positions of the two types of thread grooves are aligned, so when screwing the wheel nut/bolt to the bolt or nut to be screwed, the two types of thread grooves are aligned. The thread cutting start positions of both sides will inevitably match the thread start position of the screw on the side to be screwed, and the thread groove on the side where the screw pinch is different will be aligned with the thread on the side to be screwed. On the other hand, there is no biting, and the other screw groove on the side where the screw pitch matches can be smoothly screwed into the screw thread on the side to be screwed, and as a result, the screw grooves can be combined with two threads. It has also come to have the excellent practical benefit of ensuring proper screw tightening work without causing any problems related to screw tightening due to the threading.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, and FIG. 1 (
A), (B), and (C) are cross-sectional views showing an example of the thread forming process, FIG. 2 (A) is an enlarged cross-sectional view of section A in FIG. 1 (C), and FIG. bottom view of the unit. Figures 3 and 4 show the usage conditions, and Figures 3 (a) and (
B) is a cross-sectional view of a main part showing a screwed state, and FIG. 4 is a schematic explanatory view of a portion where a wheel of an automobile is attached. Fig. 5 shows another embodiment, and Fig. 5 (a) is a front view of the main part;
The same figure (b) is an enlarged sectional view of the B section of the same figure (a).

Claims (1)

[Claims] 1. Two types of thread grooves with different pitches are threaded in combination on the same thread forming surface of the wheel nut body or the bolt body, and both of the two types of thread grooves are threaded. An automobile wheel nut/bolt characterized in that the starting positions coincide. 2 After cutting a single thread groove on the thread forming surface of the wheel nut body or bolt body, a thread groove with a pitch different from the thread groove is added to the same thread forming surface on the same thread forming surface as the above-mentioned thread groove. A method for forming threads for automobile wheel nuts and bolts, which is characterized by threading from a cutting start position.