JPH084175Y2 - Punch assembly - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an impact type punch assembly which is mounted on a punching press or the like and used for punching a plate material.

[Conventional technology]

Conventionally, it is effective to use a punch assembly mounted on a punching press or the like to perform punching on a steel plate or the like. Many of such punch assemblies have a structure as shown in FIG. 4, for example. In FIG. 4, reference numeral 1 denotes a punch body, inside of a guide 2 formed into a hollow cylinder by fixing a punch (not shown) formed so as to correspond to the contour shape of a hole to be processed at the lower end portion. It is slidable in the vertical direction. 3 is a retainer color, guide 2
Stick to the top of the. A punch head 4 and a clamp head 5 are screwed onto the upper end of the punch body 1. Next, between the retainer collar 3 and the clamp head 5, a spring 6 (for example, a compression coil spring) that applies a force for pulling the punch body 1 upward is interposed. Although different from the one shown in FIG. 4, generally, the punch head 4 and the clamp head 5 are engraved with a male screw 7 (not shown) to be engaged with the male screw 7 engraved on the punch body 1 and locked. A nut or a double nut structure is used to prevent the punch head 4 and the clamp head 5 from coming off.

[Problems to be solved by the device]

By mounting the punch assembly having the above-mentioned configuration on, for example, a punching press and striking the punch head 4 downward by cooperating with a die assembly (not shown), desired punching can be performed on a steel plate or the like. However, when the punch head 4 and the clamp head 5 are simply made to have a double nut structure as in the prior art by repeatedly striking the punch head 4, vibration causes relative rotation therebetween, and in extreme cases, punching is performed. There is a risk that the head 4 and the clamp head 5 will fall out of the punch body 1, and it will not be possible to continue drilling, or the punch assembly will be damaged. For this reason, the punch head 4 and the clamp head 5 must be provided with a reliable retaining means.

FIG. 4 shows a retaining means described in, for example, Japanese Utility Model Publication No. 61-6970, in which the punch head 4 and the clamp head 5 are superposed via a tapered surface. That is, the taper shaft 4a of the punch head 4 is fitted in the taper hole 5a of the clamp head 5 to improve the overlapping tightening force of both due to the so-called wedge effect. A plurality of slits 8 as shown in FIG. 5 are provided on the taper shaft 4a of the punch head 4, and the taper shaft 4a is tightened inward when the punch head 4 is overlapped with the clamp head 5 as shown in FIG. Let
It is formed so as to improve the surface pressure with the male screw 7.

However, in the case of the above structure, the strength of the taper shaft 4a needs to be thin and the slit 8 needs to be provided in order to secure the tightening force. It may crack. On the other hand, if the wall thickness of the taper shaft 4a is increased in order to secure the strength, the elasticity decreases, the tightening force decreases, and it is meaningless to provide the bent slit 8.

FIG. 6 is a plan view of an essential part showing another retaining structure. In FIG. 6, the punch head 4 is provided with a slit 9 that crosses a part of the punch head 4, and a bolt 10 is screwed so as to cross the slit 9.

With the above structure, the punch head 4 is screwed to the punch body (not shown), positioned, and then the bolt 10 is tightened so that the punch head 4 is tightened so as to reduce its diameter to prevent the punch head 4 from coming off. However, even in such a configuration, it is necessary to provide the slit 9, which causes a decrease in strength and involves a risk of cracking. Further, since the bolt 10 is subject to dimensional restrictions, it is not possible to sufficiently improve the tightening force, and therefore there is a problem in that the reliability of retaining is low.

SUMMARY OF THE INVENTION The present invention solves the above problems existing in the prior art, and provides a punch assembly having a retainer or rotation preventive structure so that the punch head and / or the clamp head can securely maintain a fixed state on the punch body. With the goal.

[Means for solving the problem]

In order to achieve the above object, in the present invention, a punch body having a punch fixed to the lower end is vertically slidably inserted into a hollow cylindrical guide, and the upper end of the punch body is attached to the punch body. A punch assembly in which a punch head and a clamp head are screwed together, and a spring for applying a force for pulling the punch body upward is interposed between the retainer collar fixed to the upper end of the guide and the clamp head,
Pitches p ₁ and p ₂ (where p ₁ <
p ₂ ) male screw, pitch p _{1 in} the punch head and pitch p _{2 in the} clamp head, and the punch head and clamp head are superposed so that the punch head is positioned above the punch head. Make a stop,
I adopted the technical means.

[Action]

With the above configuration, even if the punch head and / or the clamp head is rotated in the direction of coming out of the punch body, the screw with which the clamp head is screwed is formed to have a larger pitch. The clamp head easily polymerizes, maintains the surface pressure between them, and continues the polymerized state.

〔Example〕

FIG. 1 is a longitudinal sectional view of an essential part showing a first embodiment of the present invention, and the same parts are designated by the same reference numerals as those in FIGS. 4 to 6. In FIG. 1, 11 and 12 are male screws,
It is provided at the upper end of the punch body 1, and the pitch of the male thread 11 is formed smaller than the pitch of the male thread 12. For example, the pitch of the male screw 11 is set to 1.25 mm and the pitch of the male screw 12 is formed to 1.5 mm. Next, the lower end of the punch head 4 is integrally provided with a protrusion 13 having a plane orthogonal to the axis, and is formed so as to be able to overlap with the plane portion 14 on the upper surface of the clamp head 5.
Reference numerals 15 and 16 are female threads, which are formed in the punch head 4 and the clamp head 5 so as to be screwed into the male threads 11 and 12.

With the above construction, after assembling the respective constituent members as shown in FIG. 4, the clamp head 5 is positioned by screwing the male screw 12 and the female screw 16 as shown in FIG. The repulsive force of a spring (not shown) provided below the punch head 4 is screwed onto the punch head 4 via the male screw 11 and the female screw 15,
If the protrusion 13 and the flat portion 14 of the clamp head 5 are overlapped with each other and further tightened slightly, a desired surface pressure can be obtained between the protrusion 13 and the flat portion 14. Therefore, the punch head 4 and the clamp head 5 can be fixed at predetermined positions, so that the punch head 4 and the clamp head 5 can be locked in a so-called locked state and can sufficiently resist the repeated impact force applied to the punch head 4. In this state, even if the punch head 4 and the clamp head 5 rotate relative to the punch body 1,
Since the clamp head 5 is constantly pushed upward by a spring (not shown), and the screw 16 provided on the clamp head 5 is provided on the punch head 4, the pitch is formed larger than the screw 15. The amount of advance for the same rotation angle is larger in the clamp head 5 than in the punch head 4. Therefore, the overlapped state of the protruding portion 13 and the flat surface portion 14 can be continuously maintained, and even if the punch head 4 and the clamp head 5 are rotated in the pulling-out direction, the surface pressure between the two surfaces is not reduced or rather increased. Acts like. Therefore, it is possible to greatly improve the reliability of holding the surface pressure between the punch head 4 and the clamp head 5.

FIG. 2 is a longitudinal sectional view of an essential part showing a second embodiment of the present invention, in which the same parts are designated by the same reference numerals as in FIG. In FIG. 2, 17 is a taper shaft, which is integrally provided at the lower end of the punch head 4. Reference numeral 18 denotes a taper hole, which is formed in the clamp head 5 at the same taper angle as the taper shaft 17.

With the above configuration, if the punch head 4 and the clamp head 5 are screwed onto the punch body 1 and overlapped with each other, the punch head 4 and the clamp head 5 are overlapped with each other as in the first embodiment shown in FIG.
The clamp head 5 and the clamp head 5 are in a locked state to form a stopper. In this case, the punch head 4 and the clamp head 5 overlap with each other via the taper shaft 17 and the taper hole 18,
The surface pressure between the two can be increased by the so-called wedge effect, and the retaining action can be further improved.

FIG. 3 is an enlarged vertical sectional view of an essential part showing a third embodiment of the present invention, and the same parts are designated by the same reference numerals as those in FIGS. 1 and 2. In FIG. 3, the outer diameters of the male screws 11 and 12 to be provided on the punch body 1 are formed to have substantially the same size, and the both are superposed and engraved. Even in this case, the pitch of the male thread 12 and the female thread 16 is made larger than the pitch of the male thread 11 and the female thread 15, and the clamp head 5 is arranged below the punch head 4. This is similar to the first and second embodiments shown in FIGS. Therefore, the action of securing the surface pressure and retaining the same is also the same.

In this embodiment, the case where the screw is a single screw has been described, but the operation is the same even when the screw is a multiple screw. It is also possible to combine the structure of the first embodiment shown in FIG. 1 with the structure of the overlapping screw shown in FIG.

[Effect of device]

Since the present invention has the configuration and operation as described above, the following effects can be obtained.

(1) Even if the punch head and the clamp head try to rotate in the pull-out direction, the contact surface pressure between the punch head and the clamp head increases due to the difference in pitch, so that the pull-out prevention is reliable and highly reliable.

(2) By making the punch head and the clamp head taper-engaged, the retaining action can be further improved, and the strength is greater than that of the conventional one, and there is no risk of cracking or other damage.

(3) By rotating the clamp head so as to move downward, the overlapped state can be released easily, and maintenance and inspection work is extremely easy.

[Brief description of drawings]

1 and 2 are longitudinal cross-sectional views showing the first and second embodiments of the present invention, respectively, and FIG. 3 is an enlarged longitudinal cross-sectional view of the main portion showing the third embodiment of the present invention. FIG. 4 is a longitudinal sectional view showing an example of a conventional punch assembly having a retaining structure, FIG. 5 is a side view showing the punch head in FIG. 4, and FIG. It is a figure. 1: Punch body, 4: Punch head, 5: Clamp head, 11,
12: Male thread, 15, 16: Female thread.

Claims (1)

[Scope of utility model registration request] 1. A punch body having a punch fixed to its lower end is vertically slidably fitted in a hollow cylindrical guide, and a punch head and a clamp head are screwed to the upper end of the punch body. However, in a punch assembly in which a spring that applies a force to pull the punch body upward is interposed between the retainer collar fixed to the upper end of the guide and the clamp head, a pitch is provided on the upper end of the punch body.
The male threads p ₁ and p ₂ (p ₁ <p ₂ ) are provided, and the pitch p _{1 is} inside the punch head and the pitch is inside the clamp head.
A punch assembly, wherein a p ₂ internal thread is provided, and the punch head and the clamp head are superposed so that the punch head is located above to prevent the punch from coming off.