JPH0336728Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an improvement of a pin that is driven into an object by an automatic driving tool to fix the object.

<Prior Art> Conventionally, a pin has been driven into two members (for example, a plasterboard and a steel plate) using an automatic driving tool using air pressure or the like to fix the two members to each other. Further, when driving, a driving device is also used while applying rotational force to the pin. This pin generally consists of a head and a shaft.
The head part receives a blow from the driving tool and presses the surface of the object to be fixed, and the shaft part is driven into the object to be fixed.

<Problems to be solved by the invention> This type of pin has two problems that are difficult to overcome.

One is the quality of implantation. When driving the pin, it is desirable to be able to drive the pin into the object to be fixed with as little force as possible.

Another factor is the quality of fixation, and the driven pin needs to securely fix the object.

In order to improve the quality of this fixing, it is possible to increase the frictional resistance between the pin and the object to be fixed, but increasing this resistance also increases the resistance during driving, making it difficult to achieve both. .

<Means for Solving the Problems> Therefore, the present invention provides a pin that is driven into an object to be fixed by an automatic driving tool and that fixes the object, the pin having a head and a shaft. , the tip of the shaft has a bullet-shaped head, and a thread is formed on the shaft, and the flank and corner of the leading side flank of this thread are larger than the flank angle of the trailing side flank and are fixed by the head. The above problems can be solved by providing a pin that is driven into a hole drilled in an object while being pushed wide by a leading side flank, and fixes the object by engaging the trailing side flank with the hole. Solve the points.

<Operation> The head of the pin of the present invention is hit by a driving machine and is driven into the object to be fixed. At that time, the bullet-shaped front head advances while making a hole in the object to be fixed.
Then, the shaft thread continues to the top part while expanding the hole. At this time, since the flank angle of the advancing side flank of the thread is large, the thread can advance with relatively little resistance. After the driving is completed, the screw thread engages with the hole wall and the burr formed by driving, thereby fixing the object to be fixed. In particular, since the flank angle of the trailing side flank is small, when a pull-out load is applied in the direction of the head of the pin, it is better engaged with the hole wall and the burr, thereby preventing the pin from coming off.

<Example> An example of the present invention will be described below based on the drawings.

FIG. 1 is a side view of a pin of one embodiment, and FIG. 2 is an explanatory diagram of the pin in a driven state.

This pin 1 includes a head 2 and a shaft 3, and has a leading end 4 at the tip of the shaft.

The leading portion 4 has a bullet shape. That is, the leading part 4 has a side surface 41 that bulges outward compared to a conical side surface 41' having the base of the leading part as the base and the tip of the leading part as the apex. This shape is suitable for moving forward while attaching to the object to be fixed and pushing it apart, and the pin makes a hole in the object to be fixed and moves forward with the leading end 4.

Next, a single thread 31 is formed on the shaft portion 3. The outer diameter of this thread 31 is made larger than the maximum diameter of the leading end 4, and the screw thread 31 moves forward while further expanding the hole made by the leading end 4. The outer diameter of this thread 31 may be gradually increased from the tip to the base end of the shaft, and in this case, the outer diameter at the tip side may be smaller than the outer diameter of the top portion 4. good. Also, as shown in Figure 2, if the tips of the pins protrude from the objects A and B, the outer diameter of the threads at the protruding portions can be made smaller and gradually increased toward the proximal end. good.

As shown in the enlarged part of FIG. 3, the flank angle α of the leading side flank 32 of the thread 31 is about 40 degrees, and the flank angle β of the trailing side flank 33 is about 20 degrees.
degree, and α>β. Therefore, in the driving direction of the pin (direction of the arrow in FIG. 3), the pin advances relatively easily while expanding the hole by the advancing side flank 32, but in the direction of withdrawal (direction of the arrow in FIG. 3), the pin advances relatively easily. direction), the trailing side flank 33 tends to get caught on the hole wall surface or burr, and cannot be pulled out easily. Moreover, as shown in FIG.
It is also desirable that a notch 34, such as a V-shape, is provided in the notch 34, and a burr is engaged with the notch 34 to prevent the pin from loosening.

The head 2 has a shallow tapered seat surface, and the shaft portion 3 near the head 2 is unthreaded.

Next, to explain how to use this pin 1, pin 1 is installed in an automatic driving machine, passes through the impact of air etc. to head 2, and connects gypsum board A and 0.8mm
It is driven into a fixed object made of a thick iron plate B from the top 4. By this driving, the leading part 4 moves forward while making holes in each of the objects A and B, and the shaft part 3 follows. At this time, since the advancing side flank 32 of the thread 31 of the shaft portion 3 has a large flank angle, it is driven relatively smoothly and is completely driven into the state shown in FIG. 2. Since the holes a and b formed by this driving are not formed by cutting or the like, they are incomplete and have many burrs and irregularities. Particularly, when driving the pin, a device is also used that applies rotational force to the pin while driving the pin. When such a rotational force is applied to the pin of the present invention, the threads 31 also exhibit some tapping. As a result, the thread 31 engages with the walls of the holes a and b, creating a large resistance to pulling out. In particular, when the pin is passed through as shown, the thread 31 engages with the burr b'. More specifically, at the moment the pin is driven in, it is driven in slightly deeper than the state shown in FIG. 2, and due to the repulsion of the objects A and B, it rises and returns to the state shown in the figure. Due to this repulsive rise, the thread 31 (particularly its trailing flank 33) engages with the burr or unevenness. When a pullout load is applied, the trailing flank 33 of the thread 31
Because of its large flank angle, it increases the resistance during pull-out and enables a strong bond.

It should be noted that the present invention is not limited to the above-mentioned embodiments; for example, the number of threads may be two or more. or,
The numerical values of the flank angle and the like are merely examples, and the present invention is not limited thereto. In particular, the flank angle of the trailing side flank may be a negative angle. It is desirable that the lead angle of the screw thread be a little smaller than a normal screw thread, but it will change depending on the type of object to be fixed.

<Effects of the invention> As described above, the present invention reduces the resistance during driving,
On the other hand, it has significantly improved pull-out strength,
It is possible to provide a driving pin that is not only used for temporary fixing, but also makes it possible to permanently fix construction materials.

[Brief explanation of the drawing]

Figure 1 is a side view of a driving pin of one embodiment, Figure 2 is a side view of a driving pin of one embodiment;
The figure is a side view of the same driving state, FIG. 3 is an enlarged longitudinal cross-sectional view of the main part, and FIG. 4 is an enlarged cross-sectional view. 2...Head, 3...Shaft, 4...Top, 31...
...screw thread, 32...leading side flank, 33...following side flank.

Claims (1)

[Scope of utility model registration request] A pin that is driven into an object to be fixed by an automatic driving tool to fix the object, the pin having a head and a shaft, and a tip of the shaft having a bullet-shaped head, A thread is formed on the shaft portion, a plurality of notches are formed at appropriate positions of the thread, and the flank angle of the leading side flank of this thread is larger than the flank angle of the trailing side flank,
A pin that is driven into a hole drilled in an object to be fixed by the leading end while being pushed wide by a leading side flank, and the object to be fixed is fixed by engaging the hole on the trailing side.