JP2018196915A - Tap - Google Patents

Abstract

To provide a tap for forming a thread load sharing type nut which can obtain larger fastening power by dispersing and sharing a fastening load by a thread from a fastening side to an open side.SOLUTION: A tap for forming a thread on a nut for fastening has a tool body which is rotated around an axis, and a male screw provided on an outer periphery of the tool body in order to form a whole thread load sharing type nut, which performs load sharing of fastening power during fastening over the whole of the thread by executing groove processing of a thread lateral face at a side of receiving a load of the nut, and a groove processing blade is formed on a lateral face of a thread of the male screw part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tap for forming a screw thread on a fastening nut. In particular, the present invention relates to a tap having a blade portion for distributing a load to a screw thread of a nut.

  Many bolts and nuts are used to fasten various structures. Fastening with bolts and nuts is common in aircraft, machine tools, manufacturing equipment for foodstuffs and semiconductors, automobiles / railway vehicles, agricultural machinery, and building structures. As for the nut used here, at most about 3 threads on the fastening side (the side in contact with the object to be fastened) bear the fastening load, and the other threads on the open side (opposite side of the fastening side) The share contribution ratio is low. As long as a uniform screw material and a uniform thread structure are used, such non-uniform load sharing is unavoidable and has been overlooked as having no effective improvement measures. In this way, only a limited thread is a non-uniform load sharing that shares the load, and when fastening bolts and nuts where the other threads hardly share the load, the thread shares the load equally. The fastening force is reduced compared to the case.

  One of the conventional general taps is a hand tap. After drilling a hole in the base material forming the nut, a screw thread of the nut is formed by inserting the hand tap while twisting into the hole.

  In general, many types of taps have been proposed and used for forming nuts or female threads. As one of them, a tap capable of forming a bulge-shaped depression at the bottom of a female screw has been proposed (Patent Document 1). This proposal is based on a tap having a tap body rotated around an axis and a male threaded portion provided on the outer periphery of the tap body. Forming part. When a female screw is manufactured using this tap, a constant-shaped concave portion corresponding to the convex-shaped convex portion of the tap bulge is formed at the bottom of the female screw thread. However, enlarging this female thread valley bottom has the disadvantage that it is only a reduction in the possibility of breakage at the valley bottom.

JP 2010-188444 A

  The present invention solves the above problems and forms a thread load sharing type nut that can disperse and bear the tightening load with a large number of threads from the fastening side to the opening side and obtain a larger fastening force. It provides a tap for.

The present invention provides the following inventions in order to solve the above problems.
(1) A tap for forming a screw thread on a nut for fastening, and when a nut fastens an object to be fastened together with a bolt, the screw thread side (load surface) on the side that receives a fastening load in the screw thread of the nut A screw is formed from the fastening side thread (the thread on the side of the nut that contacts the object to be fastened) to the opening side thread (the thread of the nut on the side opposite to the fastening side). In order to form a thread load sharing nut that distributes the load to the pile, the tap has a tap body 2 that is rotated about an axis, and a tap blade portion 3 that is provided on the outer periphery of the tap body, and A tap, characterized in that a grooved projecting blade 7 is formed on the side surface of a crest of a male screw-like blade 6 of the blade portion 3.
(2) The above (1) is provided with the groove machining projecting blade 7 projecting from the terminal end 4 to the start end 5 of the blade portion 3 so as to correspond to the change in the groove machining dimension of the thread surface. The described tap.
(3) The grooving projecting blade 7 on the end side 4 of the blade portion 3 is the largest, and the grooving projecting blade 7 is made smaller from the end side 4 toward the start end side 5 ( Tap as described in 2).
(4) In the nut thread, the above-mentioned (1) to (1) having a blade for grooving a thread surface (load surface) to which a fastening load is applied and a blade continuously connected to the valley bottom curved portion continuously to the blade. The tap according to any one of 3).

  ADVANTAGE OF THE INVENTION According to this invention, the tap for creating the nut which can share a fastening load with many screw threads can be provided. Thereby, the load of a bolt thread is also distributed, and a nut capable of exhibiting a larger fastening force than a conventional nut can be manufactured.

The figure (a) and partial enlarged view (b) which show the external appearance of an example of the tap of this invention. The cross-sectional schematic (a) and partial enlarged view (b) of an example of the tap of this invention. The figure which shows one example of the thread shape of the nut which formed the groove | channel in the thread side surface of the load distribution nut manufactured using the tap of this invention. The figure which shows the external appearance of the conventional general tap.

  The tap of the present invention is a tap for forming a screw thread on a fastening nut, and the material of the tap is suitable for cutting a screw on an object, and carbon such as high-speed steel, tool steel, etc. It is appropriately selected from steel, cemented carbide, and the like. Further, a coating for the purpose of hardening the surface, adhesion to the surface, etc. may be applied.

  As shown in FIG. 1 to be described later, when using a nut to fasten an object to be fastened together with a bolt, groove processing is performed on the thread side surface (load surface) of the nut on the side receiving the fastening load, and fastening at the time of fastening is performed. In order to form a thread-load sharing type nut that distributes the load to many threads, the tap 1 has a main body 2 that is rotated around an axis and a blade portion 3 that is provided on the outer periphery of the main body 2. The blade portion 3 is formed with a male threaded blade 6 (blade forming a nut thread), and a grooving projecting blade 7 (load when fastening the nut thread) is formed on the side surface of the thread 6. A blade for grooving the thread on the receiving side).

  The groove 8 in the tap axis direction that constitutes the blade surface (the cutting blades (6, 7) at the time of producing the nut are the surfaces into which the nut material is cut and the groove for discharging the chips of the material) is a straight line or spiral as in the prior art. The shape of the workpiece may be selected depending on the material, hardness, dimensions, purpose of use, or through-hole or bag-like hole of the workpiece (the inner diameter including the nut provided with a fastening screw). Three or more grooves are provided.

  When a thread is formed on the fastening nut using the tap of the present invention, the groove cutting protrusion blade 7 is provided on the side surface of the thread 6 formed on the outer periphery of the tap body 2 in the form of a male screw. The blade 7 forms a groove on the side surface (load surface) of the nut on which the fastening load of the nut is applied, and this thread effect causes the fastening force at the time of fastening to distribute the load to many threads. A load sharing nut is formed.

  Due to the load distribution of the nut threads, the load on the bolt side corresponding to the threads is also distributed, which leads to sharing of the fastening load in the entire bolt / nut thread. As a result, the axial force generated in the bolt is shared by the entire screw thread, which can lead to a reduction in the aggressiveness of the bolt.

  By continuously changing the shape of the projecting blade 7 for tapping the groove in the tap longitudinal direction, and producing a nut using the tap, it is possible to produce a nut that shares the load substantially evenly with the thread. Sharing the fastening load almost evenly with the screw thread leads to an improvement in the fastening force of the nut and a distribution of the load on the male screw of the bolt, resulting in a reduction in the thread breakage rate and an external force at the fastening part. Can be made less susceptible to adverse effects.

  In one aspect of the tap according to the present invention, a protruding blade 7 is provided from the blade 4 on the end side 4 of the blade portion 3 toward the blade on the start end side 5 so as to correspond to a change in the groove processing dimension of the thread surface. .

  In another aspect of the tap of the present invention, the protruding blade 7 on the terminal end side 4 is the largest, and the protruding blade 7 is formed so as to decrease from the terminal end side 4 toward the starting end side 5.

  In another aspect of the tap of the present invention, when a nut is manufactured using the tap, a blade for grooving a thread surface (load surface) to which a fastening load is applied in the thread of the nut, and the blade It has a blade that continuously connects the valley bottom curve part continuously.

  FIG. 4 is a side view of an example of a conventional general tap 1 ′, in which a blade portion 3 ′ is formed on the outer periphery of a part of the tap main body portion 2 ′, and the blade portion has a male screw-like blade. Yes.

  FIG. 1 is a diagram showing an appearance of an example of a tap 1 according to the present invention. Like a conventional tap, the main body 2 has a blade portion 3 on the outer periphery of a part, and the blade portion 3 is formed with a male screw-like blade 6. Moreover, it is a cutting surface of the blade at the time of producing the nut, and is provided with a groove in the tap axial direction for discharging the chips of the material. In addition to these configurations, the present invention is characterized in that a protruding blade 7 (hatched portion) is formed on the side of the external thread of the external thread 6.

  FIG. 2 is an explanatory view showing the tap of the present invention in more detail, and shows the blade portion 6 in more detail. In the schematic cross-sectional view (a), the portion painted in black is the protruding blade 7. The blade 7 in the black portion of the schematic cross-sectional view (a) corresponds to the portion painted in black in the partial enlarged view (b), and the shape of the convex portion continues from the end portion 4 of the tap toward the start end side 5. Is changing. The dimensions of the projecting blade 7 at the end of the tap are the largest, and the dimensions of the projecting blade 7 become smaller as the front end of the end becomes the front end. The black portion shown in FIG. 1 and FIG. 2 is a protruding blade formed on the side surface of the thread of the male thread portion of the tap, and is a blade that works useful for forming a thread load sharing nut.

  FIG. 3 shows an example of the shape of the nut female thread surface when a nut is produced using the tap of the present invention, wherein 9 is a nut, 10 is a bolt, 11 is a fastening side of the nut, and 12 is an opening of the nut. The side and 13 show the groove part processed into the nut for fastening load sharing. Reference numeral 14 denotes a side surface (load surface) that bears a fastening load in the nut.

The tap blade portion of the present invention is manufactured, for example, as follows.
(1) Forming a male thread having a shape in which the blade 6 and the blade 7 are combined so as to match the target thread shape of the tap material with a lathe.
(2) Groove in the axial direction of the tap so that the blade is formed. The groove itself is similar to a conventional tap.
(3) Confirm that the blade is cut to a desired degree.

  The tap of the present invention can be applied as a cutting tool, and can also be applied to a “rolling” tap that pushes / swells after drilling a pilot hole to form a shape.

  The present invention provides a tap for forming a nut that shares the load evenly across all threads.

DESCRIPTION OF SYMBOLS 1 Tap 2 Tap main-body part 3 Tap blade part 4 End side of the blade part 3 5 Start end side of the blade part 6 6 Blade formed in the male thread shape of the blade part 7 7 Projection blade for grooving 8 Tap axial direction groove

Claims (4)

  This is a tap that forms a thread on the nut for fastening. Groove processing is performed on the side of the thread that receives the tightening load of the nut, and the fastening force at the time of fastening is fastened with the thread from the fastening side to the opening side. In order to form a thread load sharing nut that distributes the load, the tap has a main body that rotates around an axis, and a male screw-like blade that is provided on the outer periphery of the main body. A tap characterized by forming a grooving blade on the side of the mountain.   The tap according to claim 1, wherein a protruding blade is provided from the terminal end side to the start end side so as to correspond to a change in a groove processing dimension of a thread surface at the time of manufacturing a nut.   The tap according to claim 2, wherein the protruding blade on the terminal end side of the blade is the largest, and the protruding blade becomes smaller from the terminal end side to the starting end side.   The tap according to any one of claims 1 to 3, further comprising: a blade for grooving a thread surface to which a tightening load of a nut is applied, and a blade continuously connected to the valley bottom curved portion.

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