GB2064040A

GB2064040A - Cylindrical pipe sockets

Info

Publication number: GB2064040A
Application number: GB8034955A
Authority: GB
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 1979-11-21
Filing date: 1980-10-30
Publication date: 1981-06-10
Also published as: IT8050031A0; BR8007568A; IT1146118B; DE2946888A1; JPS5788993A

Abstract

A method of producing a socket on a cylindrical pipe comprises welding a junction piece 3 onto a pipe 1 and making a hole through the pipe. The piece 3 is provided before welding with a surface having a line of contact conforming to the outside of the pipe around the intended hole. A uniform current during welding is thus ensured. The junction piece may be hollow or solid before the welding. Such sockets are useful for the filling of hydraulic cylinders of power steering systems. <IMAGE>

Description

SPECIFICATION Cylindrical pipe sockets The invention relates to a method of producing a socket on a cylindrical pipe. Such sockets are useful particularly for the introduction of pressure medium into hydraulic cylinders of power steering systems.

According to the invention a junction piece is welded onto the pipe and a hole is made through the pipe into the junction piece, the junction piece being provided with a surface having a line of contact conforming to the outside of the pipe around the entire circumference of the intended hole.

The method of the invention can be applied even to thin-walled pipes, and without localized heating or distortion of the material of which the pipe is made. Relatively large-diameter pipes can be treated according to the invention, but in order to ensure an optimum flow of energy there must be a certain relationship between the diameter and the height of the junction piece.

By shaping the welding face of the junction piece with a line corresponding to the penetration line of the cylindrical pipe, and equal contact surface is created and allows uniform current passage all around the intended hole. Resistance welding requires a minimum amount of energy, and thus reduces the heating of the pipe. The accuracy of the size of the pipe is thus maintained, and an oil-tight connection of high quality is created. The welding means a considerable reduction in labour and therefore a less expensive product than a soldered connection.

Drawings Figure 1 is a section through a hollow junction piece prepared for welding according to the invention: Figure 2 is a view in the direction of the arrow X of Figure 1; Figure 3 is a section along Ill-Ill in Figure 1; Figure 4 is a partial longitudinal section through a finished cylindrical pipe with a pipe socket welded onto it according to the invention plus assembled accessories; and Figure 5 is an example of a solid junction piece prepared for welding like that of Figure 1.

With reference to Figures 1 to 4, a junction piece 3 has a surface 2 to be welded to a cylindrical pipe 1. This surface 2 conforms to the penetration line of the cylindrical pipe 1, and forms an equal contact surface in the shape of an ellipse around the entire circumference of the intended hole in the piece 3. Once the piece 3 has been positioned onto the pipe 1, the parts are connected by resistance welding. Due to the line contact between the two parts at the beginning of the welding process, a uniform current passage is ensured, and thus a uniform current density.

Overheating and distortion of the cylindrical pipe is avoided since the heat transition taking place is no longer pointed but is in the form of an ellipse.

The junction 3 is prepared for welding with a bore 4. When the welding is completed it is only necessary to provide a bore 5 through the pipe 1.

The piece 3 itself may be produced at a favourable price by the cold extrusion technique. After the piece 3 has been internally screw-threaded a ringshaped piece 7 is screwed onto it by means of a hollow screw 6. A pressure medium line 8 is soldered onto the ring-shaped piece 7.

In Figure 5 a junction piece 3A is in the shape of a solid cylinder which after welding is drilled together with the pipe 1.

1. A method of producing a socket on a cylindrical pipe in which a junction piece is welded onto the pipe and a hole is made through the pipe into the junction piece, the junction piece being provided before welding with a surface having a line of contact conforming to the outside of the pipe around the entire circumference of the intended hole.

2. A method according to claim 1 in which the welding is resistance welding.

3. A method according to claim 1 or claim 2 in which the junction piece is shaped as a hollow cylinder before the welding.

4. A method of producing a socket on a cylindrical pipe as herein described with reference to the drawings.

5. A cylindrical pipe having a socket produced by a method according to any preceding claim.

New claims or amendments to claims filed on 27th February 1981 Superseded claims 1 and 2 New or amended claims:~ Original claims 3 to 5 renumbered as 2 to 4 respectively and appendancy of claim 3 corrected 1. A method of producing a socket on a cylindrical pipe in which a junction piece is resistance welded onto the pipe and a hole is made through the pipe into the junction piece, the junction piece being provided before welding with an end surface with edges beveled both inside and out and having a line of contact conforming to the outside of the pipe around the entire circumference of the intended hole.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

SPECIFICATION Cylindrical pipe sockets The invention relates to a method of producing a socket on a cylindrical pipe. Such sockets are useful particularly for the introduction of pressure medium into hydraulic cylinders of power steering systems.

According to the invention a junction piece is welded onto the pipe and a hole is made through the pipe into the junction piece, the junction piece being provided with a surface having a line of contact conforming to the outside of the pipe around the entire circumference of the intended hole.

The method of the invention can be applied even to thin-walled pipes, and without localized heating or distortion of the material of which the pipe is made. Relatively large-diameter pipes can be treated according to the invention, but in order to ensure an optimum flow of energy there must be a certain relationship between the diameter and the height of the junction piece.

By shaping the welding face of the junction piece with a line corresponding to the penetration line of the cylindrical pipe, and equal contact surface is created and allows uniform current passage all around the intended hole. Resistance welding requires a minimum amount of energy, and thus reduces the heating of the pipe. The accuracy of the size of the pipe is thus maintained, and an oil-tight connection of high quality is created. The welding means a considerable reduction in labour and therefore a less expensive product than a soldered connection.

Drawings Figure 1 is a section through a hollow junction piece prepared for welding according to the invention: Figure 2 is a view in the direction of the arrow X of Figure 1; Figure 3 is a section along Ill-Ill in Figure 1; Figure 4 is a partial longitudinal section through a finished cylindrical pipe with a pipe socket welded onto it according to the invention plus assembled accessories; and Figure 5 is an example of a solid junction piece prepared for welding like that of Figure 1.

With reference to Figures 1 to 4, a junction piece 3 has a surface 2 to be welded to a cylindrical pipe 1. This surface 2 conforms to the penetration line of the cylindrical pipe 1, and forms an equal contact surface in the shape of an ellipse around the entire circumference of the intended hole in the piece 3. Once the piece 3 has been positioned onto the pipe 1, the parts are connected by resistance welding. Due to the line contact between the two parts at the beginning of the welding process, a uniform current passage is ensured, and thus a uniform current density.

Overheating and distortion of the cylindrical pipe is avoided since the heat transition taking place is no longer pointed but is in the form of an ellipse.

The junction 3 is prepared for welding with a bore 4. When the welding is completed it is only necessary to provide a bore 5 through the pipe 1.

The piece 3 itself may be produced at a favourable price by the cold extrusion technique. After the piece 3 has been internally screw-threaded a ringshaped piece 7 is screwed onto it by means of a hollow screw 6. A pressure medium line 8 is soldered onto the ring-shaped piece 7.

In Figure 5 a junction piece 3A is in the shape of a solid cylinder which after welding is drilled together with the pipe 1.

1. A method of producing a socket on a cylindrical pipe in which a junction piece is welded onto the pipe and a hole is made through the pipe into the junction piece, the junction piece being provided before welding with a surface having a line of contact conforming to the outside of the pipe around the entire circumference of the intended hole.

2. A method according to claim 1 in which the welding is resistance welding.

3. A method according to claim 1 or claim 2 in which the junction piece is shaped as a hollow cylinder before the welding.

4. A method of producing a socket on a cylindrical pipe as herein described with reference to the drawings.

5. A cylindrical pipe having a socket produced by a method according to any preceding claim.

New claims or amendments to claims filed on 27th February 1981 Superseded claims 1 and 2 New or amended claims:~ Original claims 3 to 5 renumbered as 2 to 4 respectively and appendancy of claim 3 corrected

1. A method of producing a socket on a cylindrical pipe in which a junction piece is resistance welded onto the pipe and a hole is made through the pipe into the junction piece, the junction piece being provided before welding with an end surface with edges beveled both inside and out and having a line of contact conforming to the outside of the pipe around the entire circumference of the intended hole.