JPS6049056B2 - Bulge processing equipment - 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 racks, and head racks have traditionally been formed using a method called hydraulic bulge processing. 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. . Fig. 1 shows an example of a conventional device for performing such hydraulic bulge processing.
, 4b is a pressurizing piston, 5a and 5b are packing cylinders, 6 is a hydraulic pump, 7 is a high pressure liquid introduction hole, 8 is a pressure booster, 9a and 9b are pressurizing cylinders, 10 is a hydraulic pump, 11
12 is a mold clamping cylinder, 12 is a hydraulic pressure generating device, 13 is a pressure regulating cam, 14 is a pressure regulating valve, 15 is an inclined surface provided on the pressure regulating cam, ・16 is a follower, 17 is provided on the split mold 2b 18 is a knock-out piston, 19 is a knock-out cylinder, and 20 is a hydraulic pump. To briefly explain the method of performing 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.
is pressed to restrain the split molds 2a and 2b together.

Next, the hydraulic pressure generated by the hydraulic pump 6 is supplied to the packing cylinders 5a, 55b, 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. Seal. In this state, the high pressure liquid generated by the hydraulic pump 10 and the pressure booster 8 is supplied into the material tube 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 backing. - 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 case of the hydraulic bulge machining equipment as explained above, the machining conditions are controlled based on the relationship between the hydraulic pressure inside the material tube and the amount of axial shrinkage of the material tube, and the method is as explained below. It is something.

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, during the bulge forming process, the pressure fluid in the material tube naturally increases in pressure due to the difference between the compressed volume of the straight section of the material tube and the volume of the bulged portion, and the bulged portion 21 It may rupture. Therefore, as shown in FIG.
A piston 18, a knock-out cylinder 19, and a hydraulic pump 20 for operating the piston are provided, and the knock-out piston is brought into contact with the tip of the bulge to increase the bursting pressure and prevent bursting due to natural pressure increase. It has a complicated mechanism to do so. Further, as shown in FIG. 2, many bulges 21a, 21b, 21c, and 21d are formed on the material tube 1. In this case, as shown in Figure 3, the appropriate forming conditions become extremely narrow, and conventional equipment, which controls the amount of shrinkage of the material tube with a time lag relative to the pressure inside the material tube, can prevent rupture or buckling of the material tube. This made molding difficult.

Furthermore, in the conventional example shown in Fig. 1, the pressure on the primary side of the pressure intensifier 8 is controlled by the pressure regulating valve 14, which operates according to the amount of axial contraction of the material pipe, so that the liquid pressure in the material pipe is actually controlled. There was a drawback that the accuracy of setting was low.
4. As mentioned above, the conventional hydraulic bulge device shown in FIG. 1 requires a complicated mechanism to prevent rupture due to natural pressure increase, which has the drawback of increasing equipment costs. In addition, since the fluid pressure inside the material tube and the axial load applied to the material tube are directly controlled, and the relationship between the pressure and the amount of axial shrinkage is controlled, the accuracy of setting molding conditions is poor, resulting in complicated bulges. It had the disadvantage that it could not be molded. (1) An object of the present invention is to form a complicated bulging shape with high dimensional accuracy in bulge processing, in which a part of a tube is bulged in a mold by hydraulic pressure and axial load and formed into a desired shape. The object of the present invention is to provide a bulge processing device with low equipment cost.

O The main point of the present invention is that in a bulge processing device, the hydraulic pressure applied inside the material pipe is detected, and the axial load is adjusted so that the hydraulic pressure and the axial load applied to the end surface of the material pipe have a predetermined relationship. This is due to the installation of equipment that can control the load.

Embodiments of the present invention will be described in detail below with reference to FIGS. 4 to 7.

FIG. 4 shows a hydraulic bulge processing apparatus according to an embodiment of the present invention. Split mold 2c with tapered outer periphery
, 2d, 2e, 2f, the hydraulic bulge processing device bulges out a portion of the material tube 1 inserted into the desired shape, and each part has a tapered inner surface and restrains the split mold. A restraining cylinder 22, a restraining cylinder moving cylinder 23 that holds the restraining 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 pressurizing rod attached to the material tube. a pressure cylinder 9 that applies an axial compressive load via a pressure cylinder 25; a rod cylinder 26 that moves the mandrel in the axial direction; a fixing rod 27 that prevents the mandrel from sliding; A stopper 28 that fits, a stopper cylinder 29 that inserts and removes the stopper, a holding frame 30 that receives the action and reaction force of the device, a water pressure pump 31 that supplies high pressure liquid into the material pipe, and a pressure oil supply to the pressurized cylinder. The system is comprised of a hydraulic pump 32 that supplies water, and a device 33 that detects the hydraulic pressure of the hydraulic pump and controls the pressure of the hydraulic pump. Furthermore, Fig. 5 shows a perspective view of Fig. 4,
The hydraulic bulge processing apparatus of the present invention includes split molds 2c, 2d, 2
A mold cylinder 34 that moves the molds e and 2f in the radial direction, and a mold support stand 35 that holds the mold cylinder 34.
A support roller 36 that holds the mold support stand and moves on the holding frame 30, and a restraining cylinder support roller 37 that holds the restraining cylinder 22 are also provided. Note that 38 in FIG. 4 is a seal ring. The method of bulging the material tube 1 using such a hydraulic bulging device is to first move the fixing rod 27 in the axial direction using the rod cylinder 26, and insert the mandrel 24 into the material tube 1 that has been carried in! Furthermore, the pressure oil generated by the hydraulic pump 32 is transferred to the pressurizing cylinder 9.
The pressurizing piston 4 is advanced, and the hollow pressurizing rod 25 attached to the tip of the pressurizing piston is fitted into the mandrel.

Next, the mold cylinders 3 and 4 attached to the mold support stand 35 are operated in the radial direction to open the split molds 2c and 2d.
, 2e, 2f are closed. Subsequently, the restraining cylinder moving cylinders 23 provided on both sides are operated forward to fit each restraining cylinder 22 into the split molds 2C, 2d, 2e, 2f and restrain it. In this state, the pressure liquid generated by the hydraulic pump 31 is supplied into the material pipe from the high pressure liquid introduction hole 7 to remove the air from the material pipe 1, and then the pressurizing rod 25 is moved into the material pipe 1 by the pressurizing piston 4. Press it against the end face of the holder to seal it. Furthermore, high pressure liquid is supplied into the material pipe 1 from the high pressure liquid introduction hole 7, and at 4, the pressure of the high pressure liquid is detected and the pressure oil controlled by the hydraulic control device is further supplied to the pressurizing cylinder 9, The material tube 1 is axially compressed and expanded into a predetermined shape.
In this case, the mandrel 24, which receives the load applied to the material tube 1 by the pressure rod 25, is connected to the stopper cylinder 29.
By operating the stopper 28 and fitting it into the fixing rod 27, the stopper 28 can be fixedly supported. The feature of the hydraulic bulge processing device of this embodiment is that it detects the hydraulic pressure applied inside the material pipe and controls the axial load so that the hydraulic pressure and the axial load applied to the end face of the material pipe have a predetermined relationship. The detailed structure of the device is shown in FIG.

In the figure, 39 is a pressure control valve, 40 is a pressure control valve poppet, 41 is a spring, 42 is a guide bar, 43 is a guide roller, 44 is a cap, 45 is a hydraulic tank, 46 is a cam, 47 is a cam rod, and 48 is a Pin, 49 is piston rod, 50 is bolt, 51 is guide bush, 52 is ■
Packing, 53 is a cylinder, 54 is a pressure chamber, 55 is a hydraulic pressure introduction hole, 56 is an adjustment nut, 57 is a cap, 58 is a spring, 59 is a receiving plate, 60 is a directional control valve, 61 is a check valve, 6
2 indicates a throttle valve, and 63 indicates a water tank. A method of controlling the hydraulic pressure during bulge processing and the hydraulic pressure applied to the pressurizing cylinder, that is, the axial load applied to the material pipe using such a device, is as follows. First, when the direction switching valve 60 is excited and moved in the direction of arrow a, the pressure liquid generated by the hydraulic pump 31 is supplied into the material pipe 1 through the check valve 61a1 and the high pressure liquid introduction hole 7, and swells. Start molding.

At the same time, the pressure fluid flows through the hydraulic pressure introduction hole 55 of the cylinder 53.
is supplied to the pressure chamber 54, and moves the piston rod 49 and cam rod 47 in the direction of arrow c. As a result, the cam 46 fixed to the cam rod 47 also moves, and the guide bar 42 of the pressure control valve 39 moves in the direction of arrow e in accordance with the inclined surface 46a provided on the cam, causing the pressure control valve poppet to move in the direction of arrow e. 40 into the pressure oil hole 39a. Therefore, the pressure oil flowing into the hydraulic tank 45 through the poppet, the pressure oil hole, and the pressure oil outlet 39b is reduced, and the oil pressure applied to the pressurizing cylinder is increased, that is, the axis for applying it to the material pipe. Increase load. The above-mentioned operations are performed continuously, and bulge machining is performed by controlling the hydraulic pressure and axial load as shown in FIG. The cam 46 is shaped so that the relationship between the hydraulic pressure and the axial load is as shown in FIG. , can be arbitrarily selected using an adjustment nut 56 or the like. In addition, the method of completing molding and reducing the hydraulic pressure and axial load is basically the same operation as in the case of increasing it, but to briefly explain, the directional control valve 60 is energized and the arrow b move it in the direction of
The pressure liquid in the material pipe 1 is returned to the water tank 63 through the check valve 61 and the throttle valve 62 to reduce the pressure. Along with this, the spring 58 moves the piston rod 49, cam rod 47, 7 cam 4
6 is pushed back in the direction of arrow d, and according to the shape of the cam, the guide bar 42 and the pressure control valve poppet 40 are pushed back by the spring 4.
1, it is pushed back in the direction of arrow f. As a result, the pressure oil in the pressure cylinder 9 is transferred between the poppet 40 and the pressure oil hole 39.
During the period a, the pressure oil 9 is returned to the hydraulic tank 45 through the outlet 39b, and the oil pressure of the pressurizing cylinder, that is, the axial load applied to the material pipe becomes zero, and the series of operations is completed. In addition,
In this case, the rate of pressure reduction of the hydraulic pressure can be adjusted by the throttle valve 62. Using the hydraulic bulge processing apparatus of the present invention, a bulge process was performed on a plate-wound welded pipe with an outer diameter of 43 c) Tmlnl and a wall thickness of 14 mm.

In this case, hydraulic pressure is 1000 kgfId 1 shaft load is 1000 t
By adding 0n, it was possible to form four bulges with a height of 14-1 without causing any rupture or buckling. As described above, according to the embodiments of the present invention, the hydraulic pressure and axial load, which are the machining conditions when performing bulge machining, are directly and continuously controlled. Knockout used in the device
I no longer need the cylinder.

Furthermore, by adjusting the shape of the cam and the spring 58, it is possible to increase the accuracy of setting the hydraulic pressure and the axial load, and it has become possible to mold even complex bulged shapes without causing rupture or buckling. As an effect of the hydraulic bulge device to which the present invention is applied, it is possible to accurately control the hydraulic pressure and axial load, which are the processing conditions during bulge forming, so that even complex bulge shapes can be formed.

Furthermore, since the hydraulic pressure and the axial load are continuously controlled, there are no molding defects due to natural pressure increase, and a good molded product can be obtained. Furthermore, the structure of the control device can be simplified and equipment costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a conventional hydraulic bulge processing device, Fig. 2 is a perspective view of a bulge-formed product with a complicated bulge shape, and Fig. 3 is an explanatory diagram showing molding conditions using the control method of the conventional device. , 4th
The figure is a sectional view of a hydraulic bulge machining device according to an embodiment of the present invention, FIG. 5 is a sectional view of the equipment shown in FIG. 4, and FIG. FIG. 7 is an explanatory diagram showing an example of controlling hydraulic pressure and shaft load according to the present invention. 1...Material pipe, 2...Split mold, 31.
...Hydraulic pump, 32...Hydraulic pump,
46...Cam, 53...Cylinder, 54...
...pressure chamber, 58...spring.

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 device for pressurizing a pressure medium into the material tube, and an axial compression method for the material tube. In a processing device comprising a pressurizing means for applying a load, a pressure medium press-fitted into the material tube is introduced into a pressure chamber provided in a container, and comes into contact with the outer periphery of a cam operated by the pressure of the pressure chamber. A bulge processing apparatus characterized in that a pressure control valve is actuated by a member that is rotated to control the pressure of a pressurizing means that applies an axial load to the material tube. 2. The bulge processing apparatus according to claim 1, wherein an inclined surface is provided on the outer surface of the cam that is operated by the pressure of the pressure medium press-fitted into the material tube. 3. Claim 1, characterized in that a spring is provided as means for retaining the force acting on the cam due to the pressure of the pressure medium, and the cam is returned to its original position when the pressure is reduced. 3. The bulge processing device according to item 1 or 2.