JPH07178479A - Tube expanding device - Google Patents

Abstract

PURPOSE:To execute a bulging action and a pressing action for a tube with one pressurizing means and to easily set a pressing amount by transmitting the pressure through a coned disc spring in a time of transmitting a load of a forming element into a tube and part. CONSTITUTION:A metal tube 13 is set inside an outer die 11. A forming element 17 consisting of a macromolecular elastic material is inserted inside the metal tube 13. When a rod 16 is lowered with a pressurizing means 14 through an upper disc 15, a pressurizing element 18 compresses the forming element 17 in its axial direction. The forming element 17 bulges to its radius direction, the metal tube 13 of a part positioning at the bulging recessing part 12 is bulged inside the bulging recessing part 12. Further, by lowering the upper disc 15 with the pressurizing means 14, a coned disc spring 20 is compressed. The coned disc spring 20 deflects to its axial direction, and at the same time applies a load of the axial direction onto the tube 13 through a pusher 19, and the tube 13 is compressed to the axial direction. By selecting sheet numbers of the coned disc spring 20 and its lapping method, the pressing amount of the tube 13 against the compressing load of the forming element 17, that is, the pressing stroke of the rod 16 can be selected so as to be required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube expanding device.

[0002]

2. Description of the Related Art Conventionally, as a pipe expanding device for partially bulging a metal pipe in a radial direction, a molding element made of a polymer elastic material such as rubber is provided inside the bulging portion of the pipe to be processed. There is a pipe expanding device by so-called rubber bulging, in which a tube is inserted, compressed in the axial direction by a pressurizing means, and a part of the pipe is expanded in the radial direction by the expansion of the molding element in the radial direction.

In such a tube expanding device, in order to reduce the axial strain in the bulging portion of the tube, the molding element is pressed in the axial direction of the tube simultaneously with the compression. As such a pipe expanding device, conventionally, as shown in FIG. 4, a pipe 3 processed in an outer mold 2 in which a bulging concave portion 1 is formed.
And insert a molding element 4 made of rubber or the like into the tube 3,
This is axially compressed by the first pressurizing means 5 and the second
There is a pressurizing means 5'for pushing the tube 3 in.

Further, as shown in FIG. 5, a tube 3 is inserted into an outer mold 2 having a bulging recess 1 formed therein, and a molding element 4 made of rubber or the like is placed in the tube 3 to apply a pressing means. The molding member 4 is pressed by the rod 7 of No. 6 to swell in the radial direction, and at the same time, the urethane rubber 9 is interposed between the engaging portion 6a formed on the pressing means 6 and the pusher 8 to press the rod 7. In some cases, the urethane rubber 9 is pressurized at the same time as the operation, and the tube 3 is pushed in via the pusher 8. The left half surface of FIG. 5 shows the state before the pressurizing operation, and the right half surface shows the pressurizing operation state.

[0005]

In the conventional structure shown in FIG. 4, the pressurizing means including two cylinders such as the pressurizing means for the compactor and the pressurizing means for pushing the tube is required. , The means for controlling the hydraulic pressure for operating these pressurizing means is also required separately, which makes the apparatus large and complicated,
Further, there is a problem that this leads to a high cost.

Further, in the conventional structure shown in FIG. 5, one pressing means is sufficient, but since the tube 3 is pushed in via the urethane rubber 9, there are the following problems. As shown in FIG. 7, the characteristic of the relationship between the load and the deformation of the urethane rubber when the load is applied to the urethane rubber is not always linear with respect to the load, but has a complicated property.

Therefore, when various pipes having different materials, wall thickness, bulging amount, etc. are bulged, the number of urethane rubbers 9 is simply changed when the pushing amount of the pipes is changed. It is not possible to deal with it alone, it is necessary to prepare urethane rubber with various characteristics and calculate and combine it,
It is difficult to control the pushing amount.

Further, urethane rubber also has a problem that it is inferior in durability to metal materials. In view of the above, the present invention can solve the above-mentioned problems by allowing one pressurizing means to perform the swelling action and the pushing action of the tube and to easily set the pushing amount even when the pushing amount of the tube is changed. The purpose is to provide a device.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the first invention is to compress a molding element made of an elastic body inserted in a pipe to be processed in the axial direction of the pipe. In the tube expanding device that expands the tube by applying a compressive force in the axial direction to the tube while expanding the tube in the radial direction,
A transmission means for transmitting the load by the pressure means (14) of 7) to the end of the pipe (13) is provided, and a disc-shaped spring (20) is interposed in a part of the transmission means, and the load is the disc-shaped spring. It is characterized in that it is transmitted to the end of the pipe (13) via (20).

A second aspect of the present invention is characterized in that a plurality of the above-mentioned disc-shaped springs (20) are interposed in parallel, in series, or in a combination thereof.

[0011]

The load of the pressurizing means (14) of the compactor (17) is controlled by the disc spring (20) and transmitted to the end of the pipe (13), and the pipe (13) is pushed. Further, the disc-shaped spring (20) has a characteristic that it is linearly distorted with respect to the load applied to it, and the load and strain are simplified by the number of layers, parallel layers and series layers. Has changing characteristics.

Therefore, the relationship between the load and the strain (stroke) can be simply calculated and changed by the combination of the disc springs (20). Therefore, it is possible to easily control the load for pushing the tube with respect to the stroke of the pressurizing means for pressurizing the compactor (17).

[0013]

EXAMPLES Next, examples of the present invention shown in FIGS. 1 to 3 will be described. Reference numeral 10 is a fixed base to which an outer mold 11 is fixed. A bulging recess 12 is formed in the outer mold 11. The outer mold 11 is formed as a split mold so that the tube can be easily removed from the mold after the tube is bulged.

Reference numeral 13 denotes a metal tube to be bulged, which is installed in the outer mold 11 such that the portion to be bulged is located in the bulging recess 12. Reference numeral 14 is a pressurizing means composed of a hydraulic cylinder or the like, and by pressurizing the pressurizing means, the upper plate 15 is moved downward in FIG. A rod 16 is fixedly provided on the lower surface of the center of the upper plate 15, and a compactor 17 made of a polymer elastic material such as rubber is provided below the rod 16.

Reference numeral 18 denotes a pressurizing member provided on the rod 16, and when the rod 16 descends, the pressurizing member 18 is axially pressed through the pressurizing member 18 to expand in the radial direction. Numeral 19 is a pusher slidably fitted on the rod 16 and the lower part of which is fitted to the upper end of the pipe 13 so that the pipe 13 set in the outer mold 11 can be pushed downward, and the upper end of the pipe 13. It is designed to come into contact with and to be locked. Further, the upper portion of the pusher 19 is formed in a brim shape, and the upper surface thereof serves as a disc spring receiving surface 19a.

Reference numeral 20 is a disc-shaped spring interposed between the spring receiving surfaces 15a and 19a formed on the upper plate 15 and the pusher 19, respectively, and is installed so as to bend in the axial direction of the rod 16. One or a plurality of the disc-shaped springs 20 are stacked and installed. Reference numeral 21 is a guide tube interposed between the rod 16 and the disc-shaped spring 20.

Next, the operation of this embodiment will be described. As shown in FIG. 1, the metal tube 13 to be bulged is set in the outer mold 11, and the compactor 17 is inserted and installed in the tube 13 by the pressing means 14 through the upper plate 15 and the rod 16 When is lowered, the pressurizer 18 compresses the molding member 17 made of a polymeric elastic material such as rubber in the axial direction. This allows
The molding element 17 expands in the radial direction, and the portion of the metal tube 13 located in the bulging recess 12 bulges into the bulging recess 12.

Further, the upper plate 15 by the above-mentioned pressurizing means 14
The disc-shaped spring 20 is compressed by the downward movement of the
0 bends in the axial direction and, at the same time, applies an axial load to the pipe 13 via the pusher 19, and the pipe 13 is compressed in the axial direction.

At this time, the relationship between the load applied to the disc-shaped spring 20 and the amount of deflection of the disc-shaped spring 20 has the characteristic shown in FIG. 6 when the number of the disc-shaped spring 20 is one. That is,
The amount of deflection of the disc-shaped spring 20 has a characteristic that is almost linear in proportion to the applied load.

Further, FIG. 3 shows the characteristics of the relationship between the load and the amount of deflection when a plurality of the disc-shaped springs 20 are arranged in parallel and a plurality of the disc-shaped springs 20 are arranged in series. In addition, parallel means an arrangement as shown in FIG. 2 (a), and serial means an arrangement as shown in FIG. 2 (b).

In FIG. 3, A is one, B is two in parallel, C is three in parallel, and D is one.
In the case of arranging two stages in parallel, E shows the characteristics in the case of arranging two sheets in parallel in four stages, and F shows the characteristics in the case of arranging three sheets in parallel in four stages. As can be seen from this characteristic, in the case of the parallel arrangement, the load is doubled even with the same amount of deflection. Further, in the case of the serial connection, as compared with the parallel connection of the same number, even if the load is the same, the deflection is increased by the number of stages in the series, and the load and the deflection amount increase and decrease linearly.

From the above, by selecting the number of disc springs and the stacking method as desired, the deflection of the load and the axial direction,
That is, the relationship of strokes can be set as desired, and the setting can be made extremely easily as compared with the urethane rubber material.

Therefore, the compression load of the compactor 17, that is, the pressurization of the rod 16 is selected by selecting the number of the disc-shaped springs 20 and the stacking method (parallel or serial) to be interposed as shown in FIG. The pushing amount of the pipe 13 with respect to the stroke, that is, the compressive load of the pipe can be selected as desired.

Further, the compression load of the tube 13 with respect to the pressing stroke of the rod 16 can be controlled by variously combining the number of the disc springs 20 and the stacking method. Further, in the load control, since the relationship between the load and the strain amount of the disc spring changes linearly, it can be easily calculated simply by the number of the disc springs and the stacking method.

The pipe 13 is controlled by the load controlled as described above.
Is compressed in the axial direction, the pipe material is pushed into the bulging portion of the tube 13, and axial strain in the bulging portion is prevented.

[0026]

As described above, according to the present invention, the compression action of the compactor and the compression action of the tube can be performed by one pressurizing means. In addition, the fact that there is only one pressurizing means also means that there is only one means for controlling the pressurizing means. Therefore, it is possible to reduce the size and simplification of the apparatus, and further to reduce the cost, as compared with the prior art in which two pressurizing means and two controlling means are provided.

Furthermore, the amount of compressive load on the pipe with respect to the stroke of the pressurizing means for compressing the compact can be easily controlled by combining a simple disc spring. Further, the use of the disc-shaped spring improves the durability as compared with the urethane rubber material.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which the disc-shaped springs are stacked, (a)
Indicates a parallel state, and (b) indicates a serial state.

FIG. 3 is a characteristic diagram showing a relationship between load and deflection depending on a combination state of the disc-shaped springs.

FIG. 4 is a cross-sectional view showing a conventional tube expanding device.

FIG. 5 is a sectional view showing still another conventional tube expanding device.

FIG. 6 is a characteristic diagram showing the relationship between the load and strain of the disc-shaped spring.

FIG. 7 is a characteristic diagram showing a relationship between load and strain of conventional urethane rubber.

[Explanation of symbols]

13 ... Pipe 14 ... Pressurizing means 15 ... Upper plate 16 ... Rod 17 ... Molding element 19 ... Pusher 20 ... Disc-shaped spring

Claims (2)

[Claims] 1. A pipe formed by an elastic body inserted into a pipe to be processed is compressed in the axial direction of the pipe and expanded in the radial direction, and at the same time, an axial compressive force is applied to the pipe to expand the pipe. In the pipe expanding device, a transmission means for transmitting the load by the pressing means of the molding element to the end portion of the pipe is provided, and a disc-shaped spring is interposed in a part of the transmission means, and the load is transmitted through the disc-shaped spring. A pipe expanding device characterized by being transmitted to an end of a pipe. 2. A pipe expanding device, wherein a plurality of disc-shaped springs according to claim 1 are interposed in parallel, in series, or in a combination thereof.