JPS6153134B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tube expansion device, and more specifically, a tube expansion medium made of an elastic body is inserted into a tube to be expanded, the tube expansion medium is compressed in the axial direction, and the tube expansion device is compressed in the radial direction. This invention relates to a tube expansion device that expands the tube using an expansion force.

As shown in FIGS. 1 and 2, a conventional tube expanding device of this type has a tube to be expanded and fixed (hereinafter simply referred to as a tube) 2 in a tube hole of a tube sheet 1. into the tube 2, and insert the cylinder 3 into the inside of the tube 2.
A pressurizing rod 5 connected to a piston 4 fitted into the pressurizing rod 5 and an elastic tube expansion medium 7 attached to the pressurizing rod 5
and then supplying hydraulic pressure P into the cylinder 3, and pulling up the pressurizing rod 5 as indicated by the arrow F' in FIG. 1 via the piston 4 constituting the pressurizing means.
The tube expansion medium 7 is compressed in the axial direction between the pair of the head 6 of the pressurizing rod 5 and the seal ring 9, and the pair of the back up spring 8 and another seal ring 9'. The tube 2 is configured to expand in the radial direction with a radial expansion force of 7.

However, in the conventional tube expansion device, when inserting the pressure rod 5 and the tube expansion medium 7 into the tube 2, it is done manually. It is easy to insert the medium 7 with its axial center tilted, and since the gap between the inner diameter of the tube 2 and the outer diameter of the tube expansion medium 7 is only about 0.2 to 0.3 mm, the tube can be inserted even if the tube expansion medium 7 is slightly tilted. The inner surface of the tube 2 and the tube expansion medium 7 rub against each other, causing damage to the inner surface of the tube 2 and damage to the tube expansion medium 7, resulting in a decrease in product quality and reliability. Excessive wear and tear. And after expanding the tube,
When pulling out the pressure rod 5 and the tube expansion medium 7, the pressure rod 5 is moved in the direction of the arrow in FIG. 2 to remove the compressive load applied to the tube expansion medium 7 and to reduce the diameter of the tube expansion medium 7. Although it is pulled out after being expanded and contracted, even if the compressive load is removed, the tube expansion medium 7 may not return to its original shape due to frictional resistance between the inner surface of the expanded tube and the tube expansion medium 7, or may not return to its original shape. However, it takes a long time to pull out the wire, and therefore a large pulling force is required, so if it is done manually, the pulling out operation takes a long time. Furthermore, there is also the drawback that the above-mentioned inconvenience caused by the misalignment of the axes of the expanded tube and the tube expansion medium 7 cannot be avoided during this drawing.

In order to eliminate the various drawbacks of the conventional tube expansion device, the present invention includes the steps of: inserting a pressure rod and a tube expansion medium into the tube;
It is an object of the present invention to provide a pipe expanding device that can mechanically perform drawing in a short time.

The configuration of the present invention will be explained below based on the drawings.

3 and 4 show an embodiment of the present invention, in which a low pressure piston 18 is slidably fitted concentrically into the low pressure cylinder 10. The high-pressure piston 24 is slidably fitted concentrically to form a double cylinder shape.

Guide rods 11 are attached to both sides of one working end of the low-pressure cylinder 10, which constitute means for aligning the tube 2 to be expanded, the pressure rod 28, and the expansion medium 31. An inner flange 12, which serves as a partition wall of the low-pressure cylinder 10 and a guide member for the low-pressure piston 18, is formed on the inner surface of the low-pressure cylinder 10 in the middle in the axial direction, and the other end is sealed with an end frame 13 in the shape of a cylinder head. . The inside of the cylinder 10 is divided into first and second chambers 14 and 15 by an inner flange 12, and the first chamber 14 is connected to a first port 16 and the second chamber 15 is connected to a first port 16.
are in communication with the second port 17, respectively.

Each guide rod 1 constitutes a means for aligning the tube 2 to be expanded, the pressure rod 28 and the tube expansion medium 31.
1 is a fitting 2a on both sides adjacent to each other which is fitted into the tube plate 1.
Each guide rod 11 is formed in an outer shape to fit into the adjacent pipe 2a, and thereby
Cylinder 10, low pressure piston 1 with respect to the axis of
8. The axes of the high-pressure piston 24 are aligned, and by aligning the axes of the high-pressure piston 24, the axes of the pressurizing rod 28 and the tube expansion medium 31 connected thereto are aligned. It's summery.

The low pressure piston 18 is the first piston of the cylinder 10.
It is inserted into the chamber 14 of. A coupling ring 19 is screwed to the working end of the low-pressure piston 18, and a back-up ring 23 is screwed to the coupling ring 19. The coupling ring 19 is tightly fitted into the second chamber 15 of the cylinder 10, and the coupling ring 19 is tightly fitted into the second chamber 15 of the cylinder 10.
A chamber 20 is formed between the piston 9 and the inside of the piston 9, and the chamber 20 is divided into third and fourth chambers 21 and 22 by the head 25 of the high-pressure piston 24. The third chamber 21 is communicated with the second port 17 through the second chamber 15, and the fourth chamber 22 is opened with a hydraulic pressure introduction path 26, which will be described later.

The high pressure piston 24 is the low pressure piston 18
The head 25 is fitted into the inner central hole of the chamber 20. Further, a hydraulic pressure introduction passage 26 is formed through the interior center of the high pressure piston 24, and hydraulic pressure can be supplied into the fourth chamber 22 of the chamber 20 through the hydraulic pressure introduction passage 26. . A pressure rod 28 is connected to the working end of the high-pressure piston 24 via a boss 27, and a seal ring 30 and an elastic body are connected between the head 29 of the pressure rod 28 and the back-up spring 23. A tube expansion medium 31 and a seal ring 32 made of the same material are interposed.

The low pressure piston 18 constitutes a mechanical means for inserting the pressurizing rod 28 and the tube expansion medium 31 into the pipe 2 and pulling it out after tube expansion, and the high pressure piston 24 and the pressurizing rod 28 connected thereto constitutes a pressurizing means for compressing the tube expansion medium 31 in the axial direction.

When expanding a tube using the tube expansion device configured as described above, first, guide rods 11 constituting alignment means are inserted into the tubes 2a on both sides adjacent to the tube 2, and the guide rods 11 are aligned with respect to the axis of the tube 2. After aligning the axes of the cylinder 10 and the low pressure piston 18, and then aligning the axes of the pressure rod 28 and the tube expansion medium 31 via the high pressure piston 24, the inside of the cylinder 10 is inserted from the second port 17. When hydraulic pressure is supplied to the third chamber 21 in the chamber 20 through the second chamber 15, the low pressure piston 18 and the high pressure piston 24 are moved in the direction of arrow A in FIG. The connected pressure rod 28 and the attached expansion medium 31 are inserted into the tube 2 and set in place as shown in FIG.

Then, the hydraulic pressure in the third chamber 21 is reduced to the second chamber 1.
5 and the second port 17, the hydraulic pressure is supplied to the fourth chamber 22 in the chamber 20 through the hydraulic pressure introduction path 26 formed in the high pressure piston 24. When hydraulic pressure is introduced into the fourth chamber 22, the high pressure piston 24 and the pressurizing rod 28 connected thereto generate a lifting force F as shown by the arrow in FIG.
The expansion medium 31 is pulled up by the seal ring 3.
0 and 32, the tube 2 is expanded by the radial expansion force accompanying the axial compression of the tube expansion medium 31, and is fixed in the tube hole of the tube plate 1.

After pipe expansion, the hydraulic pressure in the fourth chamber 22 of the chamber 20 is released from the hydraulic pressure introduction path 26 in the high-pressure piston 24, and is transferred to the third chamber 22 through the second port 17 and the second chamber 15.
By supplying hydraulic pressure to the chamber 21, the high-pressure piston 24 and pressurizing rod 28 are pushed down inside the expanded pipe, and the expanding medium 31 is restored to its original shape.

When the diameter of the tube expansion medium 31 is reduced and restored to its original shape, the low pressure piston 18 is pushed up by supplying hydraulic pressure to the first chamber 14 in the cylinder 10 through the first port 16, and the high pressure The high-pressure piston 24 is pulled up accordingly, and the pressure rod 28 and the tube expansion medium 31 connected to the high-pressure piston 24 are pulled out straight along the axis of the expanded tube 2.

Then, when the pressurizing rod 28 and the tube expansion medium 31 are pulled out from the expanded tube, the guide rods 11 are removed from the tube 2a on both sides, and the entire tube expansion device is moved to the tube to be expanded next, and the same process as described above is carried out. By repeating this operation, the tubes are successively expanded and fixed in the tube holes of the tube plate 1.

The present invention has the structure and operation described above, and uses a mechanical means installed in a cylinder provided with a pressurizing means to insert a pressurizing rod and a tube expansion medium into a tube to be expanded, thereby expanding the tube. Since all the work of pulling it out from inside the rear canal can be done mechanically,
The pressurizing rod and the tube expansion medium can be inserted and removed straight along the axis of the tube, and damage to the product and tube expansion medium due to misalignment of the axes between the tube, the pressure rod, and the tube expansion medium can be avoided. It has the effect of eliminating all inconveniences.

Furthermore, as described above, the present invention uses mechanical means to insert and remove the pressure rod and the tube expansion medium into the pipe, so that the pressure rod and the tube expansion medium can be easily inserted and removed. It also has the effect of significantly reducing time.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional tube expansion device using an elastic tube expansion medium, Figure 2 is an explanatory diagram showing the operation of the tube expansion device in Figure 1 being pulled out from the inside of the pipe after expansion, and Figure 3 is the actual tube expansion device. FIG. 4 is a longitudinal cross-sectional view showing one embodiment of the invention, and is an explanatory view of the operation in the expanded tube state. 10...Cylinder, 14...First chamber, 15...
...Second chamber, 16...First port, 17...Second port, 18...Low pressure piston, 20...
Room, 21...Third room, 22...Fourth room, 2
4...High pressure piston, 25...Same head, 26
... Hydraulic pressure introduction path, 28 ... Pressure rod, 31 ...
Tube expansion medium, F...Lifting force of pressurized rod.

Claims (1)

[Claims] 1. A pressure rod, a tube expansion medium fitted onto the pressure rod, and a hydraulic means for applying compressive force in the axial direction to the tube expansion medium, and the tube to be processed is expanded by the radial expansion force of the tube expansion medium. In a tube expansion device that plastically deforms a tube in the expansion direction and fixes it to a tube sheet, the hydraulic means has a double-cylindrical shape, fixes the pressurizing rod to the piston of the high-pressure cylinder, and
A pipe expansion device characterized in that the high-pressure cylinder is fitted into a low-pressure cylinder, and the high-pressure cylinder can be driven in the axial direction by the expansion and contraction operation of the low-pressure cylinder.