JPH0357299Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial field of application] This invention uses small-diameter pilot holes pre-drilled in chassis and panels made of steel plates, aluminum plates, etc. to form large-diameter parts. This invention relates to a drilling tool used for drilling mounting holes.

[Conventional technology]

This type of drilling tool uses a steel or aluminum plate to be drilled, which is held between a fixed die and a punch, and the punch is inserted from the die side to the punch side through a pilot hole in the plate to be drilled. A hole for mounting a component that is larger in diameter than the pilot hole is drilled in the plate material by driving the rod using a hydraulic cylinder or the like and displacing the punch fixedly held by the rod toward the die side. . An example of its configuration is shown in FIG.

In the figure, reference numeral 1 indicates a perforated plate material, such as a steel plate or an aluminum plate, and specifically forms a part of a chassis or panel. This drilling tool includes a hydraulic cylinder 2, a fixed die 3 integrally held in the hydraulic cylinder 2, a drilling punch 4 installed opposite to the die 3, and one end attached to a piston rod 5 of the hydraulic cylinder 2. It consists of a punch rod 6 which is screwed onto the punch rod 6 and is inserted through a pilot hole 7 of the plate material 1 to be punched from the die 3 side to the punch 4 side, and the punch 4 is held on the other end side. The inner diameter of the die 3 and the outer diameter of the punch 4 are set to a desired hole diameter. Further, in this example, the punch 4 is configured to be held by the rod 6 by threading a threaded part on the inner surface of the through hole into the threaded part of the rod 6, and the punch 4 and the die are connected together. A punch 4 is fixed to the rod 6 so as to clamp the plate material 1 to be perforated by the punches 3 and 3.

Then, in the state shown in FIG. 2, by supplying hydraulic pressure to the hydraulic cylinder 2, the piston 8
By moving the rod 6 fixed to the piston rod 6 downward, the punch 4 shears the plate material 1 to be perforated.
A punch diameter hole is drilled in the hole.

Further, other configuration examples of the drilling tool are disclosed in, for example, Japanese Patent Application Laid-Open No. 64-57930, Japanese Utility Model Application Publication No. 64-54923, and Japanese Utility Model Application Publication No. 64-54924, etc.
The basic configuration of any drilling tool is the second
There is not much difference from the one shown in the figure, only the means of holding the punch to the rod is different.

[The problem that the idea attempts to solve]

When drilling a large-diameter hole in a plate to be drilled using this type of drilling tool, as described above, drill a small-diameter pilot hole 7 in the plate to be drilled 1 in advance, and insert the punch 4 into the rod 6. Rod 6 without the
is inserted into the prepared hole 7, and then the punch 4 is attached to the tip side of the rod 6. Therefore,
The diameter of the rod 6 must be smaller than the pilot hole 7 previously drilled in the plate material 1 to be drilled, and is usually 15 mm.
It is about φ.

On the other hand, when the punch 4 shears the plate material 1 to be perforated, a very large tensile load acts on the rod 6. For this reason, it is not impossible to imagine that the rod 6 having a thickness of about 15 mmφ would not be able to withstand the load and would break midway. If the rod 6 breaks during shearing of the plate material 1 to be punched, the large reaction force that was acting on the punch 4 will blow off parts of the punch 4 and the rod 6, which is extremely dangerous. be.

This idea was made in view of the above circumstances, and even if the punch rod were to break during the drilling operation of the plate to be drilled, it would not cause part of the punch or rod to fly away. Our technical objective is to provide a highly safe drilling tool that can eliminate the dangers of this.

[Means to solve the problem]

In order to achieve the above-mentioned object, this invention improves the structure of the punch rod of a drilling tool. That is, the drilling tool according to this invention inserts a punching rod into which a fixed die is fitted into a pilot hole drilled in a plate material to be drilled, and holds the drilling punch by fitting it onto the rod. For drilling, the punch diameter hole is punched in the plate material by sandwiching the plate material to be drilled between the punch and the fixed die, and driving the rod to displace the punch toward the die side. In the tool, a through hole passing through in the axial direction is formed in the axial center of the rod, a steel wire is inserted through the through hole, and both ends of the steel wire are respectively fixed to both ends of the rod. It is structured with the following characteristics.

Furthermore, one end of the steel wire that is passed through the through hole in the rod shaft center may be configured to be attached to one end of the rod via a compression coil spring wound around the steel wire. can.

[Effect]

In the drilling tool with the above configuration, even if the rod breaks during the drilling operation of the plate material to be drilled and breaks and splits into the distal end side and the proximal end side, the piercing tool formed in the axial center of the rod The distal end and proximal end of the rod are connected to each other by a steel wire that passes through the hole and is attached to both ends of the rod, causing part of the punch or rod to blow off. Such things are prevented.

In addition, if one end of the steel wire inserted through the through hole in the rod shaft center is configured to be attached to one end of the rod via a compression coil spring, the impact when the rod breaks will be applied to the compression coil. This is absorbed by the spring, and the impact force applied to the punch etc. is somewhat alleviated.

〔Example〕

Hereinafter, preferred embodiments of this invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing the main parts of a drilling tool according to an embodiment of the invention.

The rod 10 of this drilling tool is formed with an engaging threaded portion 16 on its distal end side, which is useful when holding the punch 12 on the rod 10, and a first threaded portion 16 on its proximal end.
In the figure, a fixing screw portion 20 for screwing the rod 10 onto a piston rod 18 of a hydraulic cylinder (not shown) is formed. A through hole 22 is formed in the axial center of the rod 10 and extends through the rod 10 in the axial direction. A steel wire 24 such as a piano wire is inserted through the through hole 22 . steel wire 24
A compression coil spring 26 is wound around one end, and the compression coil spring 26 is connected between a locking portion 28 formed at one end of the steel wire 24 and a stepped portion 30 formed on the rod 10. Retained. The other end (tip) of the steel wire 24 is engaged with the stepped portion 34 of the rod 10 by a caulking portion 32, and the caulking portion 32 is pushed into the stepped portion 34 of the rod 10 by the elastic force of the compression coil spring 26.
It is in pressure contact with the In addition, in Figure 1, 14 is a die,
36 indicates the plate material to be perforated.

To give an example of the dimensions, the large diameter portion on the base end side of the rod 10 is 19 mmφ, the small diameter portion is 15 mmφ, and the steel wire 24 is 3 mmφ.

As mentioned above, the steel wire 24 is disposed at the axial center of the rod 10 of this drilling tool, so even if the rod 10 breaks around the center during the drilling operation of the plate to be drilled, the rod 10 will not break. The broken distal end and proximal end of No. 10 remain connected to each other by the steel wire 24, so that part of the punch or rod will not be blown off.
In addition, when the rod 10 is broken, the compression coil spring 26 wound around the steel wire 24 absorbs the shock at the time of breakage, and the impact force applied to the punch or the like is somewhat alleviated.

Next, an example of the configuration of a holding mechanism for holding the punch 12 on the rod 10 will be described. The holding mechanism shown in FIG. 1 is known from Japanese Patent Application Laid-Open No. 64-57930.

The punch 12 of this drilling tool has a rod 10.
A through hole 38 of a larger diameter is formed, and the punch 12 is simply inserted into the rod 10 without engaging it. The holding mechanism 40 of the punch 12 to the rod 10 includes an inner hole 44 having a larger diameter than the engaging screw portion 16 of the rod 10, a conical hole 46 connected above the inner hole 44, and a large diameter inner hole 46 connected to the conical hole 46. with a hole 48 and one circumferential groove 50 near the top end.
A holding ring body 42 has a circumferential groove 50 formed with a plurality of through holes 52 equally spaced in the circumferential direction, and a conical hole 4 of the holding ring body 42.
6, and is divided into a plurality of pieces, for example, three pieces, in the circumferential direction, and connected to each other so as to be biased in the outer circumferential direction with a compression coil spring 56 interposed therebetween, and the rod 10 is engaged with the inner circumferential surface. A split nut 54 having a conical surface 60 and a threaded portion 58 that engages with the threaded portion 16 is disposed above the split nut 54 and is fitted into the large diameter inner hole 48 of the holding ring 42 and an adjusting ring body 62.

The adjustment ring 62 has a through hole 64 with a larger diameter than the rod 10, and can be freely moved along the axial direction of the rod 10, and has a triangular cross section on its outer peripheral surface. Two circumferential grooves 68, 70 are formed separated by a shaped annular projection 66. In addition, on the lower surface of the adjustment ring 62,
A plurality of bottomed holes 72 are drilled perpendicularly to the lower surface of the bottom surface, and are equally spaced in the circumferential direction. A compression coil spring 74 is inserted into each bottomed hole 72, and a compression coil spring 74 is inserted into each bottomed hole 72. The adjustment ring 62 elastically presses the upper surface of the split nut 54 via the coil spring 74.

A steel ball 76 is provided in each small through hole 52 of the holding ring 42.
are inserted so that they can be moved in and out. Furthermore, an O-ring 78 is disposed in the circumferential groove 50 to prevent the steel ball 76 from flying outward.

The operation of holding the punch 12 on the rod 10 by the holding mechanism 40 configured as above will be explained.

The rod 10 with the punch 12 and the holding mechanism 40 not inserted is inserted into the prepared hole 80 of the plate material 36 to be punched.
After the rod 10 is inserted into the hole, the punch 12 is inserted through the opposite side of the die 14 while holding the plate 36 to be drilled, and the cutting edge of the punch 12 is brought into contact with the plate 36 to be drilled. Next, the adjustment ring 62 of the holding mechanism 40 is shifted upward with respect to the holding ring 42, and the steel ball 76 engages one of the circumferential grooves 70 of the adjustment ring 62 under the elastic force of the O-ring 78. In the fitted state, the holding mechanism 4
0 into the rod 10, and punch its bottom surface with the punch 12.
make contact with the top surface of the At this time, the split nut 54
Since it is not receiving a very large pressing force from the adjustment ring 62, it expands in the outer circumferential direction due to the biasing force of the compression coil spring 56, and is shifted upward within the conical hole 46 of the holding ring 42. , the inner diameter of the threaded portion 58 on the inner peripheral surface thereof is the engagement threaded portion 1 of the rod 10.
6, the rod 10 can be inserted therethrough without any problem.

With the lower surface of the holding mechanism 40 in contact with the upper surface of the punch 12, the adjustment ring 6 of the holding mechanism 40
2 toward the split nut 54, the steel ball 76 of the retaining ring 42 is pushed into the annular projection 6 of the adjusting ring 62.
6 and adjust the adjustment ring 6 as shown in FIG.
2 and engages with the circumferential groove 68. Accordingly, the split nut 54 receives the pressing force from the adjustment ring 62 and moves downward while bringing the conical surface 60 into sliding contact with the inner surface of the conical hole 46 of the holding ring 42. The rod 56 is compressed in the axial direction against the biasing force of the rod 56, and the threaded portion 58 on the inner peripheral surface thereof engages with the engagement threaded portion 16 of the rod 10. This allows the holding mechanism 40 to hold the rod 10.
The punch 12 is held between its lower surface and the plate material 36 to be punched. In this state, by operating the hydraulic cylinder and displacing the rod 10 toward the die 14 via the piston rod 18, a large diameter hole is bored in the plate material 36 to be drilled.

When the drilling operation is finished, the holding ring body 42 is adjusted by either shifting the adjusting ring body 62 of the holding mechanism 40 upward with respect to the holding ring body 42 or by shifting the holding ring body 42 downward with respect to the adjusting ring body 62. By bringing the steel ball 76 into engagement with the circumferential groove 70 of the adjustment ring 62 again, the pressing force from the adjustment ring 62 to the split nut 54 is reduced, and the split nut 54 is moved upward. The split nut 54 is expanded in the outer circumferential direction by the biasing force of the compression coil spring 56, and the engagement between the threaded portion 58 on the inner circumferential surface and the engagement threaded portion 16 of the rod 10 is released and held. Mechanism 40 and rod 10
Then, remove the punch 12 from the rod 10.

Although the drilling tool of this invention has the above-described configuration, the scope of this invention is not limited by the contents of the above description and drawings.
Various modifications may be included without departing from the gist. For example, the mechanism for holding the punch on the rod is
Not limited to the above embodiments, but
The mechanism disclosed in Japanese Utility Model Publication No. 54923 or Japanese Utility Model Application Publication No. 64-54924 may be used, or as shown in Fig. 2, a threaded portion may be screwed into the inner surface of the through hole of the punch and the threaded portion may be inserted into the rod. The punch may be held in place by a rod by being screwed into the threaded portion. Further, the driving method of the rod is not limited to the hydraulic cylinder method, but may be a mechanical method or the like.

[Effect of idea]

Since this invention is constructed and operates as explained above, when using the drilling tool according to this invention, even if the punch rod breaks during the drilling operation of the plate to be punched, Parts of the punch and rod are prevented from flying off, ensuring safety during drilling work.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing the main parts of a drilling tool according to an embodiment of the invention, and FIG. 2 is a longitudinal sectional view showing an example of a conventional drilling tool. 10... Rod for punch, 12... Punch for drilling, 14... Fixed die, 16... Engaging screw part,
18...Piston rod of hydraulic cylinder, 22...
... through hole, 24 ... steel wire, 26 ... compression coil spring, 36 ... plate material to be punched, 40 ... holding mechanism for punch to rod.

Claims (1)

[Scope of claim for utility model registration] 1. A punch rod into which a fixed die is inserted,
The rod is inserted into a pilot hole drilled in the plate material to be perforated, a drilling punch is fitted and held on the rod, the plate material to be perforated is held between the perforation punch and the fixed die, and the rod is driven. In the drilling tool, the punch diameter hole is drilled in the plate material to be drilled by displacing the punch toward the die side. A drilling tool characterized in that a steel wire is inserted through the through hole, and both ends of the steel wire are respectively attached to both ends of a rod. 2. The drilling tool according to claim 1, wherein one end of the steel wire is attached to one end of the rod via a compression coil spring wound around the steel wire.