JPH0450086B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a processing device for forming a bulge in a part of a cylindrical member such as a pipe, and more particularly to a bulge processing device for forming a joint used for steel pipe structures and piping. It is.

BACKGROUND ART Bicycle parts such as various pipe joints, hanger lugs, and head lugs have been conventionally formed by a method called a hydraulic bulge process. This hydraulic bulge processing method is a plastic processing method in which a material tube is held in a split mold, and high hydraulic pressure is applied to the material tube, as well as an axial compressive load to bulge a portion of the material tube. .

Figure 1 shows an example of a conventional device that performs such hydraulic bulge machining.
is the material tube, 2a and 2b are the split molds, 3 is the mold clamping piston, 4a and 4b are the pressurizing pistons, 5a and 5b are the bucking cylinders, 6 is the hydraulic pump, 7 is the high pressure liquid introduction hole, and 8 is the pressure intensifier , 9a, 9b are pressure cylinders, 10 is a hydraulic pump, 11 is a mold clamping cylinder, 12 is a hydraulic pressure generator, 13 is a pressure regulating cam, 14
15 is a pressure regulating valve; 15 is an inclined surface provided on the pressure regulating cam;
16 is a follower, 17 is a mold hole provided in the split mold 2b, 18 is a knock-out cylinder, and 20 is a hydraulic pump.

To briefly explain how to perform bulge processing using such a device, first, the material tube 1 is inserted into the upper and lower split molds 2a and 2b, and the mold clamping piston 3 of the mold clamping cylinder 11 is inserted. The split molds 2a and 2b are pressed together and restrained. Next, the hydraulic pressure generated by the hydraulic pump 6 is pumped into the packing cylinder 5.
a, 5b, the pressurizing pistons 4a, 4b are advanced, and the tips of the pressurizing pistons 4a, 4b are pressed against both end surfaces of the material tube to seal them. In this state, the high pressure liquid generated by the hydraulic pump 10 and the pressure intensifier 8 is supplied into the material pipe 1 from the high pressure liquid introduction hole 7, and the pressure liquid generated by the hydraulic pump 6 is supplied to the pressurizing cylinders 9a, 9b and the packing. - It is supplied to the cylinders 5a and 5b, and compresses the material tube 1 in the axial direction to expand it into a predetermined shape.

In the hydraulic bulge processing apparatus shown in FIG. 1, the mold clamping cylinder 11 prevents the upper and lower split molds 2a and 2b from separating when high hydraulic pressure is applied inside the material pipe. The molds 2a and 2b are restrained, but the load for restraining these split molds is
It can be roughly estimated using equation (1).

W=DPl/100...(1) Where, W: Restraint load of split mold (Kg) D: Inner diameter of material tube (mm) p: Fluid pressure applied inside material tube (Kgf/cm ² ) L: Material Pipe length (mm) For example, a pipe with an inner diameter of 30 mm and a length of 400 mm has a hydraulic pressure of 1000 mm.
When performing bulge processing at Kgf/cm ² , the restraint load on the split mold is approximately 1200 tonf, and a clamping cylinder that can generate this much load is required. Therefore,
Conventional hydraulic bulging machines that require a mold clamping cylinder with such capabilities have the disadvantage of extremely high equipment costs.

In addition, in the conventional hydraulic bulge machining apparatus shown in FIG. It will be pushed back with a heavy load.

F ₀ = π/400D ²・p ...(2) This load becomes extremely large as the diameter of the pipe to be formed increases. For example, if the pipe diameter is 300 mm and the pressure liquid is 1000 kg
When performing bulge processing at f/cm ² , the load will be approximately 680 tonf. Therefore, it is necessary to apply pressure with the pressure cylinders 9a and 9b to balance this load, and when combined with the load applied to the material tube 1, the pressure cylinder has the disadvantage that it requires the ability to generate a very large load. It was hot.

Furthermore, in the conventional hydraulic bulge processing apparatus, the pressurizing cylinders 9a, 9b and the packing cylinders 5a, 5b are arranged on both sides so as to compress the material tube 1 evenly from both sides, so the equipment cost is reduced. This method is very expensive, and has drawbacks such as the need for complicated control in order to synchronize the pressurizing cylinders on both sides.

Furthermore, when forming many bulges 21a, 21b, 21c, and 21d on the material tube 1 as shown in FIG. Mold 2a, 2b or above,
After molding, the mold clamping piston 3, which moves only downward,
Since the processed tube cannot be extracted from the mold,
It was impossible to mold it.

Furthermore, since the method of transporting the raw pipe 1 into the split molds 2a and 2b, or carrying out the processed pipe after forming from the split molds, was carried out using an input device, a crane, etc.
This work took a long time and the processing efficiency was reduced to a fixed price.

The processing conditions of the hydraulic bulge processing device shown in Fig. 1 are controlled based on the relationship between the hydraulic pressure inside the material pipe and the amount of axial shrinkage of the material pipe, and the specific method for this is explained below. It's something like this.

A pressure regulating cam 13 is connected to a pressure piston 4a that moves as the material tube 1 contracts in the axial direction, and the pressure is adjusted by a follower 16 that moves back and forth in contact with an inclined surface 15 provided on the pressure regulating cam. Molding is performed by operating the pressure valve 14 and controlling the pressure of the hydraulic pump 10 to a predetermined relationship.

In such a hydraulic bulge processing device, the pressure fluid in the material pipe naturally increases in pressure due to the difference between the compressed volume of the straight pipe part of the material pipe and the volume of the bulge part during the bulge forming process, and the bulge part 21 It may rupture. Therefore, as shown in FIG. 1, a knock-out piston 18 that moves back and forth in the mold hole 17, a knock-out cylinder 19, and a hydraulic pump 20 that operates the piston are provided. A complicated mechanism is provided to increase the bursting pressure by contacting the tip of the bulging portion to prevent bursting due to natural pressure increase.

Furthermore, when forming many bulges 21a, 21b, 21c, and 21d on the material tube 1 as shown in FIG. 2, the appropriate molding conditions become extremely narrow as shown in FIG. Conventional equipment controls the amount of shrinkage of the material tube, which has a time delay due to pressure.
Molding was difficult due to rupture and buckling of the material tube.

The present inventors have provided a bulge processing apparatus, as described in Japanese Patent Application Laid-Open No. 148421/1983, which has a structure in which a constrained cylinder is supported in a floating manner by a cylinder and moves as the material tube contracts in the axial direction. However, there was a problem in that the operating speeds of the cylinders were different and it was difficult to set the constrained cylinder in a predetermined position in the initial state before processing.

An object of the present invention is to set a restraining cylinder at a predetermined position before processing in a hydraulic bulge processing device that bulges a part of a pipe in a mold using hydraulic pressure and axial load and forms it into a desired shape. Hydraulic bulge processing can be performed stably, has good followability as the material tube moves, can form complex bulging shapes with high dimensional accuracy, and can be processed efficiently with low equipment costs. The goal is to provide equipment.

In order to achieve the above object, the present invention provides a material tube to be bulge-molded, a split mold formed into a plurality of parts into which the material tube is fitted, a cylinder to be fitted and restrained in the split mold, and a cylinder to be fitted into and restrained by the split mold. A hydraulic bulge comprising a device for pressurizing a pressure medium into a material tube, a pressurizing means for applying an axial compressive load to the material tube, and a member that receives a reaction force of the pressurizing means and fixedly supports the material tube. In the processing device, the restraining cylinders provided on both sides of the split mold are supported by independent cylinders, the cylinder provided on the fixed member side is stopped at the stroke end, and the cylinder provided on the pressure means side is stopped. The present invention is characterized in that the initial axial position of the split mold is set by the restraining cylinder by setting the operating pressure lower than the cylinder operating pressure on the fixed member side.

According to the above configuration, when setting the restraining cylinder before processing, the operating pressure of the pressure means side cylinder is lower than that of the fixed member side cylinder, so after fitting the restraining cylinder to the split mold, the shaft is not moved. Directional positioning can be performed. Furthermore, during machining, the entire restraining cylinder moves toward the pressure receiving side due to the pressurizing force, so it also has the function of floating support. Therefore, processing efficiency and processing accuracy can be improved for complex bulged shapes. Further, since positioning and restraint can be performed by restraining cylinders provided on both sides of the split mold, a large-capacity clamping cylinder is not required, and costs can be reduced.

Embodiments of the present invention will be described in detail below with reference to FIGS. 4 to 8. FIG. 4 shows a hydraulic bulge processing apparatus according to an embodiment of the present invention. Split mold 2 with tapered outer periphery
The hydraulic bulge processing device, which bulges out a portion of the material tube 1 inserted into the tubes c, 2d, 2e, and 2f and forms it into a desired shape, has an inner surface finished with a tapered surface, and each restraint that restrains the split mold. A cylinder 22, a cylinder 23 for moving the restrained cylinder that holds the restrained cylinder, a mandrel 24 inserted into the material tube 1 and having a high-pressure liquid introduction hole 7, and a pressurizing piston 4 or a pressure rod 25 attached to the material tube. A pressure cylinder 9 that applies an axial compressive load through the mandrel, a rod cylinder 26 that moves the mandrel in the axial direction, a fixing rod 27 that prevents the mandrel from shifting, and a stopper that fits into the fixing rod. 28, a stopper cylinder 29 for inserting and removing the stopper, a holding frame 30 for receiving the action and reaction force of the device, and a release cylinder 32 fixed to the restraining cylinder via a bracket 31. FIG. 5 shows a view from A to A in FIG.
Mold cylinder 33 that moves f in the radial direction
, a mold support stand 34 that holds the mold cylinder 33, a support roller 35 that holds the mold support stand and moves on the holding frame, and a restraining cylinder support roller that holds the restraining cylinder 22. It is equipped with 36.
In addition, 37 in FIG. 4 is a seal ring.

Furthermore, the hydraulic bulge processing apparatus of this embodiment includes split molds 2c, 2d, 2e, 2f as shown in FIG.
A means for carrying the material tube 1 into the die or a means for carrying out the processed tube from the split mold after processing is provided.
In FIG. 6, 38 is a tilted table, 39
40 is a material feeding arm lifting cylinder; 41 is a trolley; 42 is a track; 43 is a material feeding arm; 44 is a material feeding arm lifting cylinder;
45 indicates a cylinder for moving the cart.

A method of bulging a material pipe 1 using such a hydraulic bulging device is explained using the hydraulic circuit diagrams shown in FIGS. 4 to 6 and FIG. 7, and the hydraulic circuit diagram and shaft load control device shown in FIG. I will explain it as follows.

First, the SOL27 of the directional control valve 102 is energized and the material input arm lift cylinder 40 is operated by a low pressure pump.
advance. This causes the lever 46 to be moved to the sixth position.
The material tube 1 is rotated in the direction of the arrow in the figure, and the material tube 1 placed on the inclined table 38 is lowered with the material input arm held at one end 39a and loaded onto the cart. Next, the SOL 25 of the directional control valve 103 is energized to advance the truck moving cylinder 45, and the truck 41 carrying the material tube is moved on the track 42 to the position of the material supply arm 43. Then, by exciting the SOL 28 of the directional control valve 101 and moving the material supply arm lifting cylinder 44 forward, the material supply arm 43 is lifted in the direction of the arrow to open the material pipes of the split molds 2c and 2d. , 2e, 2f. In this state, SOL2 of the directional control valve 92
1 to retract the stopper cylinder 29,
At the stroke end, the sequence valve 93 acts, and at the same time SOL19 of the direction control valves 89, 91,
23 to advance the rod cylinder 26,
Insert the mandrel 24 into the material tube. Next, the SOL 22 of the directional control valve 92 is energized to move the stopper cylinder 29 forward, and the stopper 28 is fitted into the fixing rod 27 to restrain the mandrel 24 from moving in the axial direction. Then, SOL2 of the directional control valve 101
9 is energized, the material supply arm lifting cylinder 44 is retreated, and the material supply arm 43 is lowered. Thereafter, SOL5 of the deflection control valve 66 is energized to move the pressurizing cylinder 9 forward, and the pressurizing rod 25 is fitted to the tip of the mandrel 24. In this state, the SOL15, 17 of the direction control valves 95, 96 are energized to advance the mold cylinder 33, and the split molds 2c, 2d, 2
Close e, 2f. Continued direction control valves 79, 85
The SOLs 10 and 12 are excited to advance the restraining cylinder moving cylinders 23 provided on both sides, and each restraining cylinder 22 is fitted into the split mold and restrained. In this state, as shown in FIG. 8, the pressure liquid generated by the water pressure pump is supplied into the material pipe from the high pressure introduction hole 7 to remove air, and then the pressurizing rod 25 is inserted into the material pipe by the pressurizing piston 4. Press it against the end face of the holder to seal it. Further, the high pressure liquid generated by the water pressure pump is supplied into the material pipe from the high pressure liquid introduction hole 7, and the pressure control valve 61 is controlled by the cam 145 which detects the pressure of the high pressure liquid and moves back and forth. Pressure oil controlled in this way is supplied to the pressurizing cylinder 9, and the material tube is compressed in the axial direction and expanded into a predetermined shape.

When the processed tube is taken out of the hydraulic bulge processing device after the material tube is bulged into a predetermined shape in the above-described process, the device is operated according to the rules opposite to those described above.

One of the features of the hydraulic bulge machining apparatus of this embodiment is that in the hydraulic circuit diagram shown in FIG.
Excite SOL4 and check pilot check valve 6
3 is opened and controlled by the pressure control valve 62 to operate at low pressure. This reduces the time required for moving the pressurizing cylinder 9 forward and backward, and also reduces the shock when stopping.

When the restraining cylinder 22 moves forward, the direction control valves 83 and 8
The SOLs 13 and 14 of No. 7 are excited to form a differential circuit, thereby increasing the forward speed of the restrained cylinder moving cylinder 23. Further, the operating pressure for forward and backward movement is controlled to a low pressure by the remote control valve 75 by energizing SOL1 of the direction control valve 76, and the restraining cylinder 22 is
After fitting into f, SOL2 of the direction control valve 76 is energized, and the restraining cylinder is tightened at a high pressure set by the pressure control valve 72, thereby restraining the split mold. Further, the restrained cylinder moving cylinder 23b on the rod cylinder 26 side is stopped at the end of the stroke, and the restrained cylinder moving cylinder 23a on the pressurizing cylinder 9 side is provided with a pressure reducing valve 80 to lower the pressure and the fitting is completed. The split mold is positioned in the axial direction so that it does not move backward.

In addition, in the hydraulic circuit diagram shown in FIG. 7, a sequence valve 93 is provided in the hydraulic circuit of the stopper cylinder 29 and the rod cylinder 26, and when the stopper cylinder 29 moves back and forth and reaches the end of its stroke, the pressure in the circuit is reduced. When the pressure rises above the set pressure, the rod cylinder 26 is activated. This makes it possible to ensure movement and restraint of the mandrel.

Furthermore, when supplying pressure liquid into the material pipe, as shown in FIG. The high pressure liquid generated in step 134 is supplied into the material pipe. By using the low pressure pump 126 and the high pressure pump 134 in combination in this way, processing time can be significantly shortened.

Another feature of the hydraulic bulge machining device of this embodiment is that it detects the hydraulic pressure applied inside the material tube and adjusts the axial load so that the hydraulic pressure and the axial load applied to the end surface of the material tube have a predetermined relationship. This is achieved by installing a device that can control the load. As shown in FIG. 8, when the SOL 30 of the directional control valve 140 is excited and moved in the direction of arrow a, the pressure fluid generated by the water pressure pump 134 is transferred to the check valve 142 and the high pressure fluid introduction hole 7.
The material is fed into the tube through the tube, and expansion molding begins. At the same time, pressure fluid is supplied to cylinder 149, causing cam rod 146 to move in the direction of arrow c. As a result, the cam 145 fixed to the cam rod 146 also moves, and the set pressure of the pressure control valve 61 is adjusted according to the inclined surface 145a provided on the cam, thereby controlling the hydraulic pressure and shaft load. It's summery.

As described above, according to the embodiments of the present invention,
The operating time of each cylinder can be shortened by using a differential circuit or a combination of a low pressure pump and a high pressure pump. In addition, the split mold can be positioned and restrained by restraining cylinders provided on both sides of the split mold, eliminating the need for large-capacity mold clamping cylinders used in conventional devices.

Furthermore, the machining conditions, hydraulic pressure and axial load, can be directly controlled.
By installing a control device, it is now possible to mold even complex bulged shapes without causing rupture or buckling.

As described above, according to the present invention, in a hydraulic bulge processing device that bulges a portion of a tube within a mold using hydraulic pressure and an axial load to form a desired shape, a predetermined position of a restraining cylinder before processing is used. It is a liquid that can be set stably, has good followability as the material tube moves, can mold complex bulging shapes with high dimensional accuracy, and can be processed efficiently with low equipment costs. A pressure bulge processing device can be provided.

That is, as an effect of the hydraulic bulge processing apparatus of the present invention, the structure of the apparatus can be simplified and the equipment cost can be reduced. In addition, it is easy to carry in, process, and take out the material tube into the apparatus, resulting in an effect of improving work efficiency.

Furthermore, since the hydraulic pressure and axial load can be controlled with high precision, complex bulging shapes can be formed well.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional hydraulic valve processing device.
Fig. 2 is a perspective view of a bulge molded product with a complicated bulging shape, Fig. 3 is an explanatory diagram showing molding conditions using a conventional control method, and Fig. 4 is a hydraulic bulge according to an embodiment of the present invention. 5 is a cross-sectional view of the processing device shown in FIG. 4, FIG. 6 is an overall view showing one embodiment of means for carrying in and out the material pipe, and FIG. 7 is a hydraulic Circuit diagram, FIG. 8 is a hydraulic circuit diagram. DESCRIPTION OF SYMBOLS 1...Material tube, 2...Split mold, 9...Pressure cylinder, 22...Restricted cylinder, 23...Restricted cylinder moving cylinder, 26...Rod cylinder, 27...
Fixing rod, 28... Stopper, 134... Water pressure pump.

Claims (1)

[Scope of Claims] 1. A material tube to be expanded-molded, a split mold formed into a plurality of parts into which the material tube is fitted, a cylinder fitted and restrained by the split mold, and a cylinder that is pressurized within the material tube. A hydraulic bulge processing device comprising a device for press-fitting a medium, a pressurizing means for applying an axial compressive load to the material tube, and a member fixedly supporting the material tube by receiving a reaction force of the pressurizing means, The restraining cylinders arranged on both sides of the split mold are supported by independent cylinders, and the cylinder provided on the fixed member side is stopped at the stroke end,
The initial axial position of the split mold is set by the restraining cylinder by setting the working pressure of the cylinder provided on the pressure means side to be lower than the working pressure of the cylinder on the fixed member side. Hydraulic bulge processing equipment. 2. The hydraulic bulge machining apparatus according to claim 1, wherein the fixed support member is moved to a predetermined position by a rod cylinder, and is restrained from moving in the axial direction by fitting a stopper.