JP2018079478A - Burring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus which can improve workability and reduce limitation to an object which can be processed.SOLUTION: A cylindrical work object 1, in which a prepared hole is processed at a prescribed position, is fitted to an outer peripheral side of a shank 22 having a shape corresponding to an inner surface shape of the work object 1, and split type dies 5a, 5b, which have an opening hole 51 having an inner diameter equal to an outer diameter of a standing wall 12 to be formed at a position of the prepared hole, and are divided at a position of the opening hole 51, are mounted to an outer peripheral side of the work object 1 so that the opening hole 51 is coincident with the prepared hole, thereby arresting the work object 1 by the dies. By applying a liquid pressure from a bottom of a lateral hole 24 provided at the prescribed position of the shank 22, a punch 4 built in the lateral hole 24 is extruded toward an outer side of the work object 1, and a marginal part of the prepared hole 11 is expanded to an outer side by the punch 4, thereby forming the standing wall 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a burring method and an apparatus for forming a branch seat on the surface of a cylindrical body such as when a pipe having a smaller diameter is connected to a plastically deformable cylindrical body such as metal or resin.

  When connecting a small-diameter tube so as to branch out into a cylindrical body of metal, resin, etc., it is preferable to widen the hole of the connection portion to form a branch seat in order to smooth the cross-sectional change of the flow path. For this purpose, a molding process that extends the tube wall around the hole and widens the skirt portion is called a burring process. As a burring method, for example, the one shown in FIGS. 1 (a) and 1 (b) of Patent Document 1 is known. This will be described with reference to FIG.

  As shown in FIG. 6 (a), a pilot hole 110 is processed in advance in the metal tube 100 that is the object to be processed. A cored bar 93 is inserted into the tube, and the cored bar 93 is provided with a storage hole 92 for storing a burring ball 91 having a diameter sufficiently larger than that of the lower hole 110 at a position corresponding to the lower hole 110. A thread groove 94 is machined at the center position of the burring ball 91, and a lifting pin 96 having a threaded portion 95 corresponding to the thread groove is waiting above the thread groove 94 and the lower hole 110. The periphery of the pilot hole 110 of the metal tube 100 is held by a clamp 97.

  First, the lifting pin 96 is lowered while rotating as indicated by the arrow in FIG. 6A, and the screw portion 95 is screwed into the thread groove 94 of the burring ball 91 to fix the burring ball 91 to the lifting pin 96, and then FIG. When the lifting pin 96 is raised as shown in b), the burring ball 91 passes through the lower hole 110 of the metal tube 100, and at that time, the periphery of the lower hole 110 is pushed out and pulled out to the outside of the metal tube 100. A target burring wall 120 is formed around the periphery, and one burring process is completed.

  Thereafter, the burring ball 91 is removed from the pull-up pin 96 for the next processing and returned to the housing hole 92 of the cored bar 93, which is a manual operation.

  On the other hand, in Patent Document 2, the bottom of the punch corresponding to this burring ball is a slope, and a wedge member corresponding to this slope is pushed into the tube from the side of the cored bar, and instead of lifting by the lifting pin, the wedge is used. It is described that the same processing is performed by pushing up the punch. According to the method and apparatus described in Patent Document 2, the above-described manual operation of attaching / detaching a burring ball can be eliminated.

JP 54-109062 A JP-A-6-344039

  In the method described in Patent Document 1, it is necessary to set the burring ball directly under the pilot hole and the lifting pin, and the work of screwing and removing each time is required, so the workability is poor. is there. Further, since the outer diameter of the burring ball 91 is increased due to the structure of the burring ball, that is, the thread groove 94 is essential, burring with a very small diameter cannot be performed.

  Moreover, in the method and apparatus described in Patent Document 2, a space for moving the wedge is required. Moreover, in order to effectively convert the pressing force on the wedge into the lifting force of the punch and to reduce the force that presses the punch in the lateral direction or the moment acting on the punch, the inclination angle (or taper angle) of the wedge is set. Therefore, the amount of wedge stroke required to raise the punch by a predetermined distance (that is, the length of the space) must be increased. As described above, in order to sufficiently raise the punch, it is necessary to push the wedge fully, so that there is a new problem that the burring processing position is restricted in a tubular body with a closed bottom.

  It is an object of the present invention to provide a burring method and an apparatus capable of executing the method, which can improve workability and reduce restrictions on objects that can be processed.

  According to the method of the present invention, a cylindrical workpiece whose pilot hole is processed at a predetermined position is fitted on the outer peripheral side of a shaft portion having a shape corresponding to the inner shape of the workpiece, and the pilot hole is positioned at the pilot hole. A split-type die having an opening hole with an inner diameter equal to the outer diameter of the rising wall to be formed and divided at the position of the opening hole is an outer periphery of the workpiece so that the opening hole matches the lower hole. The punch that is mounted in the side hole is restrained with the die, and the punch built in the side hole is applied by applying liquid pressure from the bottom of the side hole provided at a predetermined processing position of the shaft part. The burring method is characterized in that the rising wall is formed by extruding the object outward and pushing the edge of the lower hole outward by the punch.

  Further, the apparatus of the present invention includes a shaft portion for fitting a cylindrical workpiece having a pilot hole formed at a position where a rising wall is to be formed to the outside, and the shaft portion to be pressed by liquid pressure. A punch that is pushed out from the shaft portion toward the lower hole to expand the periphery of the lower hole toward the outer surface side of the object to be processed to form the rising wall, and an inner side of the shaft portion of the punch A flow path formed inside the shaft portion so as to supply the liquid to the end of the shaft, a pressurizing chamber for pressurizing the liquid supplied to the flow path to generate the liquid pressure, and the shaft portion The workpiece is fitted to the outside of the workpiece to be bound to restrain the workpiece, and an opening having a shape corresponding to the outer shape of the rising wall is provided at a position corresponding to the lower hole. And a divided structure that is divided at the position of the opening hole A burring apparatus; and a die.

  The apparatus of the present invention may further include a base part from which the shaft part protrudes, and the pressurizing chamber may be provided inside the base part.

  The apparatus of the present invention may further include a fastening member that fastens the die for restraining the workpiece to be fitted to the shaft portion to the base portion.

  Furthermore, in the apparatus of the present invention, a positioning portion that determines a relative position of the die with respect to the shaft portion may be provided between the die and the base portion.

  In the apparatus of the present invention, the liquid may be an incompressible fluid, and may further include an air vent that selectively discharges air from the flow path.

  According to the method of the present invention, since burring can be performed by applying liquid pressure to the punch, any operating instrument is connected to the punch, or the operating instrument is removed from the punch for further processing. As a result, work such as removal can be eliminated. As a result, according to the method of the present invention, it is possible to improve workability when performing burring on a cylindrical workpiece.

  Further, according to the apparatus of the present invention, the movable part for burring processing may be only the punch, so that the space to be reserved for the operating member may be small, and therefore the overall size of the apparatus is large. The thickness can be reduced. Therefore, according to the apparatus of the present invention, it is possible to perform burring even on a workpiece having a small inner diameter or a workpiece having a short axial length and one end closed. Restrictions on the size, structure, or direction of the rising wall to be formed can be reduced.

It is a front view which shows the burring processing apparatus in this invention Example in a partial cross section. It is a side view which shows the burring processing apparatus in this invention Example in a partial cross section. It is a perspective view which shows the holder of the burring processing apparatus in this invention Example. It is a perspective view which shows the die | dye which consists of a pair of division | segmentation piece of the burring processing apparatus in this invention Example. It is a perspective view which shows the cylindrical process target object which processed in the Example of this invention. (A) of the processing apparatus in a prior art is sectional drawing which shows before a process and (b) after a process.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. 1 is a partially sectional front view showing an embodiment of the present invention, FIG. 2 is a side view of the same, FIG. 3 is a perspective view of a holder, and FIG. 4 is a perspective view of a split die. FIG. 1 shows a state in which the processing is finished, and FIG. 2 shows a state before the processing by a solid line and a state in which the processing is performed by a broken line.

  This processing apparatus mainly includes a holder 2 and a die 5. As shown in FIG. 3, the holder 2 includes a base portion (or main body portion) 21 and a protruding portion 22 that protrudes from the base portion 21. The protruding portion 22 corresponds to the shaft portion in the embodiment of the present invention, and is a portion having an outer shape corresponding to the inner shape of the workpiece 1. For example, if the workpiece 1 is a cylindrical body, the protruding portion 22 is The shaft section has a circular cross section.

  The base 21 is formed with a vertical hole 23 into which a piston (or plunger) 3 that can be pushed in by an external force is inserted. The inside of the vertical hole 23 is filled with an incompressible fluid (liquid) such as oil, and the liquid is pushed by the piston 3 to increase the pressure. Therefore, the vertical hole 23 is pressurized in the embodiment of the present invention. It corresponds to a room.

  The protrusion 22 includes a punch 4 that is pushed outward at a predetermined processing position, and a lateral hole 24 that is built in so as to move the punch 4 back and forth without causing liquid leakage. In the present invention, the axial direction of the cylindrical workpiece 1 is referred to as “longitudinal” and an arbitrary direction not limited to the axial direction is referred to as “lateral”, and other than the radial direction is included in the “lateral hole”. Shows a lateral hole in the radial direction.

  A flow path 25 that connects the vertical hole 23 and the horizontal hole 24 is formed inside the base 21 and the protrusion 22. The flow path 25 is filled with the above-described liquid such as water, oil, or grease. The flow path 25 communicates with the inner end of the projection 22 of the horizontal hole 24, and the pressure generated by the piston 3 in the vertical hole 23 is applied to the end of the punch 4 in the horizontal hole 24. To act on the part. In addition, since it is necessary to remove internal gas (air) when filling the liquid in the flow path 25, the ball-type air vent mechanism 26 is provided.

  A pressing mechanism provided outside the holder 2 is connected to the piston 3. The pressing mechanism in the embodiment of the present invention may be any mechanism that can apply axial thrust to the piston 3. In the example shown in FIG. 1, a hydraulic jack 6 is used as a pressing mechanism.

  The punch 4 will now be described. The punch 4 in the embodiment described here has a bullet shape with a sharp head. For the purpose of burring only, the punch 4 may be in the shape of a ball. However, in order to be stored in the horizontal hole 24 and to enter and exit with liquid pressure, a cylindrical portion is provided and a seal such as an O-ring is provided. Since it is necessary to fit the member Sr, the punch 4 is a bullet that has both a cylindrical head and a sharpened head for deforming the periphery of the workpiece 1 by expanding the prepared hole. Shape is preferred. 1 and 2, the solid line indicates the punch 4 at the standby position, the imaginary line indicates the punch 4 at the position after processing, and the processing object 1 is indicated by the shape after processing.

  Further, the die 5 will be described. The die 5 is for adjusting the shape by suppressing deformation such as waving of the burring wall that is a rising portion formed on the workpiece 1, or for avoiding or suppressing abnormalities such as cracking of the burring wall. And an opening hole for introducing a burring wall expanded by the punch 4. Since the burring wall is pushed into the opening hole by the punch 4, the burring wall protrudes outward in the radial direction of the workpiece 1 and is pushed into the die 5. On the other hand, the die 5 is fitted on the outer peripheral side of the workpiece 1. Therefore, if the burring wall remains in the opening hole of the workpiece 1, the die 5 cannot be extracted from the workpiece 1. Therefore, the die 5 has a split structure so that the die 5 can be removed from the workpiece 1 after burring. An example is shown in FIG.

  The die 5 is constituted by a pair of divided pieces 5a and 5b formed in a substantially ring shape so as to be fitted on the outer peripheral side of the cylindrical workpiece 1 and restrain the workpiece 1. The divided pieces 5a and 5b are symmetrical to each other, and the concave portions 51a and 51b having a semicircular cross section centering on an axis passing through a position off the center are a part of the opposing surfaces of the divided pieces 5a and 5b. Is formed. That is, the die 5 is configured to be divided at a position of a pilot hole described later. These concave portions 51a and 51b form an opening hole 51 having an inner diameter substantially equal to the outer diameter of the burring wall to be formed by combining the divided pieces 5a and 5b. Therefore, since it is necessary to fit each of the divided pieces 5a and 5b without causing the recesses 51a and 51b to shift, a pin hole 53 is formed on the mating surface of one of the divided pieces 5a, and the mating surface of the other divided piece 5b. In addition, a knock pin 52 that is fitted into the pin hole 53 and determines the relative position of each of the divided pieces 5a and 5b is formed.

  Further, the opening hole 51 needs to coincide with the lateral hole 24 formed in the protruding portion 22. Therefore, a positioning pin 54 for determining a relative position of the die 5 with respect to the protrusion 22 is formed on the surface of the base portion 21 facing the die 5 so as to protrude. On the other hand, a positioning hole (not shown) that fits the positioning pin 54 is formed on the surface of the die 5 that faces the base portion 21. These positioning pins 54 and the positioning holes fitted therein correspond to the positioning portions in the embodiment of the present invention. Note that the positioning pin 54 may be provided in the die 5 and the positioning hole may be provided in the base 21.

  Furthermore, a fastening member for fixing the die 5 to the holder 2 is provided. In the example shown in FIGS. 1 and 2, the fastening member is a bolt 7, and through holes 55 through which the bolt 7 passes are formed in each of the divided pieces 5 a and 5 b constituting the die 5. A screw hole 56 for screwing the tip portion of 7 is formed.

  Next, the burring method according to the present invention will be described using an example in which the above-described apparatus is used. A cylindrical object is prepared as the workpiece 1 and a pilot hole 11 is formed at a predetermined location. The workpiece 1 is not limited to metal but may be made of synthetic resin, and the shape thereof is a pipe shape with both ends in the axial direction open, or a cup shape with one end closed, etc. It may be an appropriate shape. The lower hole 11 is a through hole for determining a processing position and guiding the punch 4, and is formed in the workpiece 1 as a through hole having an inner diameter significantly smaller than the inner diameter of the burring wall to be finally formed. deep.

  The workpiece 1 is fitted to the outer peripheral side of the protrusion 22 so that the lower hole 11 coincides with the lateral hole 24 of the protrusion 22. Needless to say, the punch 4 is retracted into the lateral hole 24. Next, the die 5 is fitted on the outer peripheral side of the workpiece 1. That is, the divided pieces 5a and 5b are fitted to and closely attached to the outer peripheral side of the workpiece 1, and the divided pieces 5a and 5b are brought into close contact with each other on the mating surfaces and combined with each other. In this case, the split pieces 5 a and 5 b can be combined in a normal state by fitting the knock pin 52 and the pin hole 53, and the concave portions 51 a and 51 b form the opening hole 51.

  Further, by fitting a positioning hole (not shown) in the die 5 to the positioning pin 54 in the base portion 21, the relative position between the die 5 and the protruding portion 22 (the workpiece 1) is determined, and the opening hole 51, the lower hole 11, and the like. Match. In this state, the die 7 is fixed to the holder 2 by inserting the bolt 7 into the through hole 55 of the die 5 and screwing it into the screw hole 56 in the base portion 21.

  In this state, when the hydraulic jack 6 is operated to press the piston 3 in the vertical hole 23 toward the horizontal hole 24, the liquid filled in the vertical hole 23 is pressurized, and the pressure is applied to the flow path 25. It is transmitted to the punch 4 through the fluid inside, and the punch 4 is pushed out of the protrusion 22. As described above, since the workpiece 1 is fitted to the protrusion 22 so that the lower hole 11 coincides with the lateral hole 24 (that is, the punch 4), the punch 4 is pushed out so as to pierce the lower hole 11. Then, the pilot hole 11 is expanded. In the peripheral portion of the lower hole 11, elongation deformation similar to deformation caused by so-called stretch flange processing occurs, and cracks are caused while being sandwiched between the outer peripheral surface of the punch 4 and the inner peripheral surface of the opening hole 51 of the die 5. Without generating, a burring wall 12 extending to the outside of the workpiece 1 and corresponding to the rising wall of the present invention is formed. Even if the punch 4 presses the workpiece 11 in the radial direction on the portion of the lower hole 11, since the die 5 restrains the workpiece 1 from the outside, the diameter of the workpiece 1 is large. There will be no deformation such as.

  The thrust of the punch 4 at the time of burring performed in this way is the product of the pressure of the liquid applied to the end on the inner side of the projection 22 and the pressure receiving area. 23 and the cross-sectional area ratio between the lateral holes 24 can be arbitrarily set. Care must be taken so that the punch 4 does not jump out of the horizontal hole 24. However, there is no problem if the depth of the vertical hole 23 is set to a required stroke or less.

  The burring wall 12 is not only formed outward in the radial direction of the workpiece 1, that is, toward the normal direction of the workpiece 1, but is also formed in a direction offset in parallel to the radial direction. It can also be configured. FIG. 2 shows an example thereof. In FIG. 2, the symbol a indicates the position of the center line of the entire apparatus (projection 22), the symbol b indicates the center position of the lower hole 11, and the symbol c indicates the punch 4. The position of the center of is shown. That is, in this example, since the processing position of the burring is slightly offset from the center of the original cylindrical body (processing object 1), the center of the pilot hole 11 and the punch 4 is centered from the center of the entire apparatus (projection 22). It is further shifted. By shifting the position of the lower hole 11 and the center of the punch 4, the height of the burring wall 12 to be formed is not uniform, the right side is slightly higher in FIG. 2, and the height of the cut end is horizontal (burring wall Near 12 centerlines). In order to connect the pipes after burring, it is preferable to machine the cut once. However, the construction shown in FIG. 2 facilitates the machining.

  As long as the punch 4 does not jump out of the lateral hole 24 in the process as described above, the punch 4 is retracted by returning the piston 3 and returns to the standby position. When the punch 4 does not sufficiently return to the standby position (inside the horizontal hole 24), the head of the punch 4 is pushed toward the standby position with an appropriate tool. Therefore, it is preferable to form the opening hole 51 of the die 5 as a penetrating portion opened on the outer surface of the die 5.

  After the processing is completed, the bolt 7 fixing the die 5 to the base 21 is removed, the die 5 is removed from the base 21, and the fastening between the split pieces 5a and 5b is released. Next, the workpiece 1 with the die 5 still fitted is extracted from the protrusion 22, and then each of the divided pieces 5 a and 5 b is extracted from the workpiece 1. The procedure for removing the die 5 and the workpiece 1 is arbitrary. One of the divided pieces 5 a is extracted from the workpiece 1, and then the workpiece 1 is extracted from the protrusion 22, and the workpiece 1 is removed from the workpiece 1. It is good also as extracting the other division piece 5b.

  As described above, according to the burring method and the burring apparatus in the embodiment of the present invention, the punch 4 is moved back and forth with respect to the workpiece 1 by the liquid pressure to form the burring wall 12. The burring process can be executed by operating. Therefore, the machining operation is easy and the workability of the burring process can be improved. In addition, even if the object to be processed is cylindrical, even if the object to be processed has a small diameter or a cup shape with one end closed due to the small space required for burring. Can be performed, and restrictions on the shape and dimensions of the workpiece can be reduced. Furthermore, since there is no member to be moved other than the punch 4, the space required for the apparatus is reduced, and the burring apparatus can be reduced in size and weight.

  In addition, this invention is not limited to the Example mentioned above, The processing target object which this invention makes object should just be a cylindrical thing which used the metal, the nonmetal, for example, resin etc. as a raw material. Here, the tube shape is not limited to a cylinder but a tube having a square cross section such as a square or a triangle, and may or may not have a bottom on one end side. However, it goes without saying that the outer surface of the protrusion of the holder and the inner surface of the punch are matched with this. Although it deviates slightly from the image of burring, if it is considered that the holder is the lower die and the die is the upper die, in principle, this is a processing method that can be performed even on a plane that is not cylindrical.

  In the burring process of the present invention, the processing position may be shifted from the center as described above, and the direction of the pipe to be connected may be oblique rather than perpendicular to the axial direction of the cylindrical body. Moreover, when the workpiece 1 has the bottom part 13 as shown in FIG. 5, it can also be comprised so that burring processing may be given to the bottom part 13, and there is no problem even if it is a position close | similar to a side part or a bottom part. . It can be arbitrarily selected depending on the position and orientation of the lateral hole 24 provided in the holder 2. The tube may be a tube without a bottom and having a bottom, and it is easy to perform a plurality of burring processes on a long cylindrical body. When processing with a punch protruding in the direction parallel to the central axis of the workpiece, the workpiece is provided with a protruding part in the radial direction, such as a flange, and the protruding part is formed into a die or protrusion. It is preferable to prevent the workpiece from coming off from the protruding portion by hooking on the portion.

  Further, in the present invention, as the means for pushing the piston 3, other appropriate means other than the hydraulic jack 6 in FIG. And it is convenient to provide the bracket 8 for receiving the reaction force accompanying the pushing of the piston 3. Further, the die may be configured to be divided in the radial direction in addition to the structure that is divided in the axial direction. In short, the die is configured to be divided at the portion of the opening hole into which the burring wall is inserted. Just do it.

  DESCRIPTION OF SYMBOLS 1 ... Work object, 2 ... Holder, 3 ... Piston, 4 ... Punch, 5 ... Dies, 5a, 5b ... Divided piece, 6 ... Hydraulic jack, 7 ... Bolt, 8 ... Bracket, 11 ... Pilot hole, 12 ... Burring Wall 21, base portion 22, projection portion 23, vertical hole, 24 lateral hole, 25 flow path, 51 opening hole, 51 a, 51 b concave portion, 52 knock pin, 53 pin hole, 54 positioning pin 55 ... Through hole, 56 ... Screw hole, Sr ... Seal member.

The present invention is a metal, for example, to connect small diameter tubes, and the like than the plastically deformable cylindrical body such as a resin, to burring pressurized KoSo location to form a branch seat to the cylindrical surface.

The present invention improves the workability, and to provide a burring machining apparatus capable of reducing the constraint of the object can be processed.

The apparatus of the present invention includes a shaft portion for fitting a cylindrical workpiece having a pilot hole formed at a position where a rising wall is to be formed to the outside, and a base portion provided in a state in which the shaft portion is protruded. the built in the shaft portion, forming a pressed by the rising wall spread on the outer surface side of the workpiece around the lower hole by being pushed toward the lower hole from the shaft portion by the liquid pressure Punch, a channel formed inside the shaft so as to supply the liquid to the inner end of the shaft of the punch, and pressurizing the liquid supplied to the channel a pressure chamber formed in said base portion in so that to generate a liquid pressure, the inserted one end into the compression chamber, a piston for pressurizing the liquid by pushing the other end from the outside into said base, Outside the workpiece to be fitted to the shaft portion A divided structure that constrains the object to be processed and has an opening hole having a shape corresponding to the outer shape of the rising wall at a position corresponding to the lower hole, and is divided at the position of the opening hole It is a burring apparatus characterized by having a die.

In the apparatus of the present invention, the liquid may be an incompressible fluid, and may further include an air vent that selectively discharges air from the flow path.
Furthermore, the apparatus of the present invention can have a die having a characteristic configuration. Specifically, the die in the present invention is fitted on the outside of the workpiece to be fitted to the shaft portion. It may be formed of a divided piece that is formed in a ring shape that restrains the workpiece and is divided at a plane perpendicular to the center axis of the die and passing through the center of the opening hole.
In that case, the opening hole is a hole passing through a position where the center axis of the opening hole is off the center of the die, and each of the divided pieces is a plane passing through the center axis of the opening hole. It may be a configuration having a concave part with a semicircular cross section.

According to the apparatus of the present invention, the movable part for the burring process may be only the punch, so that the space to be reserved for the operating member may be small, and thus the overall size of the apparatus is reduced. Can be small. Therefore, according to the apparatus of the present invention, it is possible to perform burring even on a workpiece having a small inner diameter or a workpiece having a short axial length and one end closed. Restrictions on the size, structure, or direction of the rising wall to be formed can be reduced.

The apparatus of the present invention includes a shaft portion for fitting a cylindrical workpiece having a pilot hole formed at a position where a rising wall is to be formed to the outside, and a base portion provided in a state in which the shaft portion is protruded. The shaft part is built in the shaft part so as to be off the center of the shaft part and offset in parallel to the radial direction of the shaft part, and is pushed by liquid pressure and pushed out from the shaft part toward the pilot hole. The punch that spreads the periphery of the lower hole to the outer surface side of the workpiece to form the rising wall, and the shaft portion so as to supply liquid to the inner end portion of the shaft portion of the punch. A flow path formed inside, a pressure chamber formed in the base to pressurize the liquid supplied to the flow path to generate the liquid pressure, and one end inserted into the pressure chamber By pushing the other end into the base from the outside. A piston for pressurizing the liquid, when it is formed on the workpiece a ring so that to restrain the is fitted to the outside of the workpiece which is fitted on the shaft portion together, the lower having said a shape corresponding to the outer shape of the rising wall and the shaft portion apertures hole around the axis passing through the off-center position of a position corresponding to the hole, and at the position of the openings A die having a divided structure to be divided, and a positioning portion that determines a relative position of the base and the die in a state in which the punch and the opening hole are made to coincide with each other. A burring apparatus comprising a positioning pin formed on one surface of a die facing each other and a positioning hole formed on the other surface and fitted with the positioning pin .

The apparatus wherein the liquid of the present invention, a non-compressible fluid, but it may also be a further comprising constituting the air vent for selectively discharging air from the flow path.

Claims (6)

  A cylindrical workpiece whose pilot hole is processed at a predetermined position is fitted on the outer peripheral side of the shaft portion having a shape corresponding to the inner shape of the workpiece, and a rising wall to be formed at the pilot hole is formed. A split-type die having an opening hole with an inner diameter equal to the outer diameter and divided at the position of the opening hole is mounted on the outer peripheral side of the workpiece so that the opening hole matches the lower hole. The workpiece to be processed is restrained by the die, and the punch built in the horizontal hole is moved outward of the workpiece by applying a liquid pressure from the bottom of the horizontal hole provided at a predetermined processing position of the shaft portion. The burring method is characterized in that the rising wall is formed by pushing out and pushing the edge of the lower hole outward by the punch. A shaft portion that fits the cylindrical processing object formed with a pilot hole at a position where the rising wall is to be formed,
Built in the shaft portion, pressed by liquid pressure and pushed out from the shaft portion toward the lower hole, the periphery of the lower hole is expanded to the outer surface side of the workpiece to form the rising wall. Punch and
A flow path formed inside the shaft so as to supply a liquid to the inner end of the shaft of the punch;
A pressurizing chamber for generating the liquid pressure by pressurizing the liquid supplied to the flow path;
An opening having a shape corresponding to the outer shape of the rising wall at a position corresponding to the lower hole while being fitted to the outside of the processing object fitted to the shaft portion and restraining the processing object. A burring apparatus having a hole and a dice having a divided structure divided at the position of the opening hole. A base portion from which the shaft portion protrudes;
The burring apparatus according to claim 2, wherein the pressurizing chamber is provided inside the base portion.   The burring apparatus according to claim 3, further comprising a fastening member that fastens the die for restraining the workpiece to be fitted to the shaft part to the base part.   The burring apparatus according to claim 4, wherein a positioning portion for determining a relative position of the die with respect to the shaft portion is provided between the die and the base portion. The liquid is an incompressible fluid;
The burring apparatus according to any one of claims 2 to 5, further comprising an air vent for selectively discharging air from the flow path.