Slot shaping appts.

Abstract

Provided is a groove forming apparatus with which an annular groove having high accuracy of shape is formed on a metallic pipe. This groove forming apparatus is provided with a supporting roller 10 having an annular concave groove 12a formed along the peripheral direction on the outer peripheral surface, a driving motor 20 for rotating the supporting roller 10 around the axial center, a press roller 30 which is provided with an annular projected line part 31b formed along the peripheral direction on the outer peripheral surface and elevating and lowering mechanisms 25, 35, 38 for vertically elevating and lowering the press roller 30 and constituted so that the annular groove 91 is formed on the outer peripheral surface in the end part by clamping and pressing the metallic pipe 90 with the press roller 30 and the supporting roller 10. The press roller 30 is arranged in a position where is offset on the opposite side to the rotating direction of the supporting roller 10 on the basis of a vertical plane including the axial line of the supporting roller 10.

Description

technical field [0001] The present invention relates to a groove forming device for forming an annular groove for engaging the coupler on the metal pipes when two metal pipes facing each other are connected by a coupler. Background technique [0002] When connecting two metal pipes facing each other, in the past, such as Figure 5 and Figure 6 couplers shown. This coupler 100 is composed of: an annular sealing member 101 that is inserted into a metal pipe 90 from both sides, and an annular groove 91 that accommodates the sealing member 101 and is engaged with and connected to each metal pipe 90 . An annular coupler body 102 is formed. and also, Figure 5 is a perspective view showing the general structure of the coupler, and Figure 6 is its cross-sectional view. [0003] The aforementioned coupler body 102 is composed of three members, the first member 105, the second member 106, and the third member 107. The fixing pin 109 joins the end portion of the first member 10...

AI Technical Summary

Problems solved by technology

[0012] However, in the above-mentioned conventional groove forming device 80, since the pressing roller 82 is arranged directly on the support roller 81, there is a problem that the shape accuracy such as the circularity of the aforementioned annular groove 91 cannot be processed to high precision. exist

[0013] That is, when the pressing roller 82 is pressed against the rotating metal pipe 90, as Figure 8 As shown, friction occurs at the contact portion between the metal tube 90 and the pressing roller 82. Therefore, due to the frictional force in the tangential direction of rotation, the pressing roller 82 is in a state where its position is easily displaced in the tangential direction. There is a tendency to recede, and the pressing force applied to the metal pipe 90 is unstable due to such receding displacement, resulting in poor shape accuracy of the formed annular groove 91

[0014] As mentioned above, although the pressing roller 82 is provided in a rotatable manner, for example, even if the pressing roller 82 is in a rotatable state using a bearing or the like, the frictional resistance inside the bearing cannot be completely eliminated. As a result, the metal pipe 90 and the frictional resistance of the contact portion of the pressing roller 82 cannot be completely eliminated

[0015] In this way, when such an annular groove 91 with poor shape precision is formed on the metal pipe 90, when the aforementioned coupler 100 is used to connect two metal pipes 90, there will be a gap between the engagement protrusion 104 and the joint body 102 of the coupler main body 102. The poor engagement between the annular grooves 91 makes the extrusion of the sealing member 101 insufficient, so that the sealing member 101 cannot be sufficiently crimped on the outer peripheral surface of the metal pipe 90. As a result, liquid leakage caused by poor sealing, metal The problem that the tube 90 falls off from the coupler main body 102, etc.

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