JP2519440B2 - Method for manufacturing male screws for fastening timber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object] The present invention provides a method for manufacturing a male screw for timbering a wood using a die that can be easily screwed in to fasten a timber to obtain a male screw that is hard to remove. The purpose is.

〔Constitution〕

In screw rolling, the rivet of the raw material is sandwiched between the moving die and the fixed die, and the moving die is moved. Meat flows into the die trough and is made into the thread portion of the male screw.

Generally, in order to make a male screw having a step portion that bulges radially outward in a part of the thread trough, as shown in FIG.
If the triangular ridges 52a, 52b, 52c, 52d are provided in the die mountain portion 58 of 51 along the rolling direction of the rivet for each rotation pitch of one rotation, the portions of the cavities 52a, 52b, 52c, 52d As shown in FIG. 2, the step 54 is formed in the thread trough 57 of the male screw 53 without the rivet being pushed.

However, even if the outer surface 55 on the upstream side of the male screw 53 in the male screw rolling direction (hereinafter referred to as the screw return direction side) is provided with the step portion 54 parallel to the diameter line 56, the protruding step portion is formed.
Since the tip of 54 collides with the inner surface of the subsequent recesses 52b, 52c, 52d and is crushed, the step portion 54 is finished so that the outer surface 55 on the screw return direction side is parallel to the diameter line 56. Was impossible.

On the other hand, when the male screw is manufactured by the method of the present invention, the die 1 is used as shown in FIG. In the die crest portion 8 on the surface of the die 1, the recesses 2a, 2b, 2c are arranged in a row in the horizontal direction along the rolling direction of the male screw to a depth larger than the required depth D _1.
The inner surface 9a, 9b, 9c on the screw return direction side of these recesses is provided with D ₂ and does not deform it without interfering with the tip of the expanded portion of the male screw formed by the upstream recess. Further, for example, it is formed so as to be inclined upward by about 45 degrees or more with respect to the die surface. Further, the final recess 2d provided in the finishing portion on the downstream side of the male screw rolling direction has a shallow depth to a required depth D _1, and the inner side surface 9d on the screw return direction side is almost the surface of the die. It is formed on a right-angled surface.

Therefore, when rolling the male screw, the recess 2
In a, 2b, and 2c, the inflated portion 4a is once formed by greatly inflating in the thread trough portion 7 of the male screw 3 (FIG. 4 (a) shows the case of the recess 2a, for example), and the final recess. In place 2d, the expansion part
The height of 4a is adjusted to the required amount, and excess meat is poured in the screw return direction, so that the outer surface 5 on the screw return direction side 5
Is finished into a step portion 4 which is substantially parallel to the diameter line 6 (FIG. 4 (b)).

It should be noted that both the moving die and the fixed die may be provided with the same shaped recess, or only one die may be provided with only a lateral groove so that the step 4 of the male screw 3 does not abut. Good.

If a wood screw is explained as an example of a male screw, as shown in FIG. 5, a conventional wood screw 60 has a head 11, a shaft part 12 without a screw, and a diameter approximately equal to the thickness of the shaft part 12. A threaded portion 63 having a threaded portion 16 and a tapered cone 14 formed in a tapered cone shape.
The diameter of the thread root 15 in the threaded portion 63 is approximately the same as the diameter from the continuous portion with the shaft portion 12 to the continuous portion with the tip conical portion 14.

The method of fastening the wood screw 60 to the wood is to provide elasticity such that the wood thread is spread laterally at the tip conical portion 14 and enters the wood without returning to the original state of the wood without providing a female screw on the wood. It is fixed by friction with the screw entry part.
Therefore, in the conventional wood screw 60 having the thread troughs 15 that are substantially parallel and have the same diameter, the thread troughs 15 and the thread crests 16 are entirely covered from the beginning of the screwing to the end of the screwing. It will enter while causing friction with the wood.

〔effect〕

The step portion 4 manufactured by the method of the present invention has an inclination that swells radially outward in the screw entry direction (downstream side of the male screw rolling direction) and the outer surface 5 on the screw return direction side is substantially parallel to the diameter line 6.
The wood screw 10 having a, as shown in FIGS. 6 and 7,
Upon entering the wood 70, after the step 4 formed in the thread trough 15 of the screw portion 13 enters the wood 70, the thread diameter of the female screw formed on the wood 70 is the thread trough of the wood screw 10. Since it is made larger than the diameter of 15, a gap 71 is created between the thread trough 15 of the wood screw 10 and the crest of the female screw formed on the wood 70, and friction with the wood 70 causes friction with the wood 70. Stays only at the tip of.

As a result, compared to the conventional wood screw 60 that enters while causing friction on both the screw thread portion 16 and the screw root portion 15 over the entire length, the wood screw 10 can greatly reduce the screwing force. Therefore, the operator's fatigue is reduced and the conventional wood screw is used.
It is possible to prevent breakage and cutting of the groove for screwing and the wood screw itself seen in 10. It is also possible to eliminate the need to replace the driver, which required several trains a day. Wood 70 if using glue
It is also possible to apply a constant thickness to the gap 71 between the wood screw 10 and the wood screw 10.

After screwing in, as shown in Fig. 8, wood
The elasticity of 70 fills the gap 71 and forms a female thread of the wood 70 having the same shape as the wood screw 10 to fix the wood screw 10.
When attempting to unscrew the wood screw 10, the female screw of the wood 70 formed in accordance with the thin portion of the thread trough 15 of the wood screw 10 is pushed to the diameter of the step 4 of the thread trough 15 of the wood screw 10. Since it has to be widened and the tip of the step 4 has a sharp shape with an outer surface 5 that is almost parallel to the diameter line 6, it is more firmly fixed than the conventional wood screw 60 that is fixed only by friction. You can do it.

That is, according to the method for manufacturing a male screw for timber according to the present invention, a male having a sharp stepped portion having an outer surface substantially parallel to the diameter line is used by using the die having the characteristic configuration as described above. The screw can be manufactured.

Incidentally, the method of manufacturing the male screw according to the present invention is, in addition to the wood screw, a coach screw, a bent one, a hanger vault,
It is clear that it can also be used as a tapping screw.

[Brief description of drawings]

FIG. 1 shows a die used in a conventional method for producing a male screw, (a) is a plan view, and (b) is AA in (a).
FIG. 2 is a sectional view taken in the direction of the arrow, FIG. 2 shows a state in which a male screw is manufactured using a conventional die, (a) is a state explanatory diagram showing a state of the male screw in the first recess of the die, and (b) is a final state. 3 is a state explanatory view showing a state of the male screw in the recess of FIG. 3, FIG. 3 shows a die used in the method for producing the male screw of the present invention,
(A) is a plan view, (b) is a sectional view taken along the line BB in (a), FIG. 4 shows a state in which a male screw is manufactured using the die according to the present invention, and (a) is the first of the dies. FIG. 5 is a state explanatory view showing the state of the male screw in the recess, FIG. 5B is a state explanatory diagram showing the state of the male screw in the final recess, FIG. 5 is a side view showing the conventional wood screw, and FIG. The wood screw manufactured by the method of this invention is shown, (a) is a side view, (b) is (a).
7 is a cross-sectional view taken along line CC in FIG. 7, FIG. 7 is a state explanatory view showing a state where the wood screw manufactured by the method of the present invention is entering wood, and FIG. 8 is a wood screw manufactured by the method of the present invention. It is a state explanatory view showing a state where it is being fixed to timber. 1 ... Die, 2a, 2b, 2c, 2d ... Recess 3 ... Male screw, 4 ... Step 4a ... Expansion part, 5 ... Outer surface 6 ... Diameter line, 8 ... Die crest 9a, 9b, 9c, 9d …… Inside surface, 10 …… Wood screw 7,15 …… Thread trough, D ₁ …… Required depth D ₂ …… Depth

Claims (1)

(57) [Claims] 1. A plurality of recesses are provided at a predetermined pitch along a rolling direction of the male screw on a die crest portion for forming a thread trough of the male screw, and the recesses form the thread troughs of the male screw. A method for producing a male screw by rolling so as to form a step portion that bulges radially outward, wherein a final recess on the downstream side in the male screw rolling direction is formed to a required depth, and The inner surface is formed on the upstream side of the male screw rolling direction of the recess in a direction substantially perpendicular to the die surface, and the recess in front of the final recess is formed deeper than the required depth, and Use a die that is formed by inclining the inner surface of the recess on the upstream side in the male screw rolling direction toward the upstream side in the male screw rolling direction by a predetermined angle upward. An inflated part that bulges higher than the required depth above is formed in the thread valley part of the Is the deformation of the expanded portion of the male screw to the height of the required depth above and the meat from the expanded portion is allowed to flow to the upstream side of the male screw rolling direction, and the male screw rolling direction that is almost parallel to the diameter line of the male screw. A method for manufacturing a male screw for fastening wood, comprising forming a step having an outer surface on the upstream side.