JP5479155B2 - Method and apparatus for closing tube body - Google Patents

Description

  The present invention relates to a closing method and an apparatus for a tubular body for performing aperture restriction and sealing at an end of the tubular body, and constitutes a cylinder device (buffer) for buffering vibrations of vehicles such as automobiles and railway vehicles. The present invention relates to a tube body closing method and apparatus suitable for use in a cylinder (tube) or the like.

  In general, a vehicle such as an automobile or a railway vehicle is provided with a cylinder device (a shock absorber) between a vehicle body and wheels, and this cylinder device is configured to mitigate vibrations generated during traveling. Here, for example, as a cylinder device for an automobile, for example, a double cylinder type hydraulic shock absorber (twin tube type shock absorber), a single cylinder type hydraulic shock absorber (mono tube type shock absorber), or the like is used.

  For example, the outer cylinder (outer tube, base shell) constituting a double cylinder type hydraulic shock absorber, the cylinder (tube, base shell) constituting a single cylinder type hydraulic shock absorber, etc. are closed at one end in the axial direction. It is configured as a bottomed cylinder. Then, as a processing technique for forming such a bottomed tube, for example, the opening peripheral edge of the tubular body is joined by squeezing the opening peripheral edge of the tubular body toward the inner diameter side. A closing process for drawing and sealing is known (see, for example, Patent Document 1).

  Here, the closing process according to Patent Document 1 heats the end of the tube and rotates the female tool relative to the rotating tube while rotating the female tool along the axis of the tube. Are moved relative to each other, and a mandrel having a molded portion at the tip is inserted into the tube body to perform mouth-squeezing and sealing toward the female tool.

Japanese Patent Laid-Open No. 2003-200241

  By the way, when forming a bottomed cylinder from a tubular body by the closing process as described above, it is important to ensure the sealing property (air tightness, liquid tightness) of the portion to be sealed (the bottom of the bottomed cylinder). Become. And in order to ensure sealing performance, at the final stage of the closing process, an appropriate pressure is applied to the portion to be sealed (portion that becomes the bottom) so that the portion is properly joined. There is a need.

  Here, in order to perform proper joining, for example, it is conceivable to strictly manage the volume (protrusion volume) of the portion of the tubular body that is apertured and sealed. More specifically, the protruding volume is determined according to the thickness of the tube before the closing process is started and the mounting position of the tube to the chuck (the amount of protrusion). It is conceivable to strictly regulate the positioning accuracy of the pipe body.

  However, strictly controlling the protruding volume in this way may lead to an increase in processing cost, such as troublesome and reduced productivity. In addition, it is necessary to manage the protruding volume taking into account the displacement of the chuck over time and the positional shift over time associated with the wear of the female tool, etc., which can be cumbersome and lead to increased machining costs. There is.

  The present invention was made in view of the above-described problems of the prior art, and even if the thickness tolerance of the tubular body and the positioning accuracy of the tubular body are not strictly regulated (even if the width of the projecting volume is widened), It is an object of the present invention to provide a tubular body closing method and apparatus capable of ensuring the sealing performance of the sealed portion (the bottom portion after processing).

  In order to solve the above-mentioned problems, the present invention heats an end of a tube and rotates the female tool relative to the rotating tube while rotating the female tool along the axis of the tube. The present invention is applied to a tube closing method in which a body is moved relative to each other, a mandrel having a molded portion at the tip is inserted into the tube, and mouth-opening and sealing are performed toward the female tool.

  The closing processing method employed by the invention of claim 1 is characterized in that, in the final stage of the mouth-drawing and sealing, the inside of the tubular body is formed by a pressure rod that moves in the axial direction along the axis of the mandrel. It is to pressurize the bottom surface.

  On the other hand, the invention of claim 4 is directed to a rotating means for rotating the tubular body, a heating means for heating the end of the tubular body, and an axis of the tubular body while rotating with respect to the rotating tubular body. A relatively moving female tool, and a mandrel having a forming part for forming the inner bottom part of the tubular body at the tip and inserted into the tubular body, and relatively moving the female tool and the mandrel By this, the present invention is applied to a closing processing apparatus for a tubular body that performs aperture drawing and sealing at the end of the tubular body.

  According to a fourth aspect of the present invention, the mandrel is provided with a rod insertion hole extending along an axis, and the rod insertion hole moves in the axial direction within the rod insertion hole. The present invention is configured to provide a pressure rod that pressurizes the inner bottom surface of the tubular body.

  According to the present invention, the inner bottom surface of the tubular body is pressurized by the pressure rod at the final stage of the aperture stop and the sealing, so that the thickness tolerance of the tubular body and the positioning accuracy of the tubular body are not strictly regulated. (Even if the control range of the protruding volume is widened), the sealing performance of the portion to be sealed (the portion that becomes the bottom after processing) can be secured.

It is a longitudinal cross-sectional view which shows the closing process apparatus by the 1st Embodiment of this invention in the state before giving a closing process to a pipe body. It is a longitudinal cross-sectional view which shows a closing process apparatus in the state of the middle stage of a closing process. It is a principal part expanded sectional view which shows the pipe body in FIG. 2, a female tool, a mandrel, a pressure rod, etc. in the state which is applying pressure to the inner bottom face of a pipe body with a pressure rod. It is a principal part expanded sectional view which shows the pipe body by which the closing process was carried out. It is a flowchart which shows the work procedure of closing process. It is a principal part perspective view which shows the pressurization rod of the closing processing apparatus by the 2nd Embodiment of this invention. It is an expanded sectional view of the same position as the K section in Drawing 4 showing a closed tube.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a tubular body closing method and apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

  1 to 5 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a tubular body as a workpiece to be subjected to a closing process by a closing processing apparatus 2 which will be described later. The tubular body 1 is supported by a chuck apparatus 3 constituting the closing processing apparatus 2.

  Here, as shown in FIG. 1, the tube body 1 has an open end in a state before the closing process is performed. 2 and 3, the end portion (opening peripheral edge portion) of the tube body 1 is subjected to a closing process, so that the end portion of the tube body 1 has a mouthpiece as illustrated in FIG. 4. And it is shape | molded by the bottomed cylinder which was sealed and became the bottom part 1A. The bottomed cylinder (the tube body 1 after the closing process) is, for example, a cylinder device (buffer) for an automobile, more specifically, an outer cylinder (an outer tube, a double cylinder type hydraulic shock absorber). Base shell) and a cylinder (tube, base shell) constituting a single cylinder type hydraulic shock absorber.

  Reference numeral 2 denotes a closing processing device that performs a closing process on the tube body 1. The closing processing device 2 includes a chuck device 3, a high-frequency heating coil 4, a female tool 5, a mandrel 9, and a pressure rod 15, which will be described later. It is roughly constituted by. Then, the closing processing device 2 relatively squeezes a female tool 5 and a mandrel 9 which will be described later, thereby squeezing and sealing the end of the tube 1 to process the tube 1 into a bottomed tube.

  Reference numeral 3 denotes a chuck device as rotating means. The chuck device 3 rotates the tube body 1 around the axis AA of the tube body 1 while supporting the tube body 1. Here, the chuck device 3 rotates the chuck 3A around the axis AA of the tube 1 and the chuck 3A that holds the tube 1 with the tube 1 positioned in the axial direction and the radial direction. A driving motor (not shown) is generally configured.

  Reference numeral 4 denotes a high-frequency heating coil as a heating means, and the high-frequency heating coil 4 heats an end portion of the tube body 1 supported by the chuck 3A. Here, the high frequency heating coil 4 has an insertion hole 4 </ b> A through which the tube body 1 can be inserted at the center. The high-frequency heating coil 4 is supported by a tool stand (not shown) described later, and moves along the axis AA of the tube body 1. Then, in a state where the end portion of the tube body 1 is inserted into the insertion hole 4A of the high frequency heating coil 4, the end portion of the tube body 1 is heated to a predetermined temperature (for example, a mouthpiece and a mouthpiece) by energizing the high frequency heating coil 4. Heating to a temperature suitable for sealing).

  Reference numeral 5 denotes a female tool for joining the peripheral edge of the opening while narrowing the peripheral edge of the opening at the end of the tubular body 1 toward the inner diameter side. While rotating about the axis B-B of the tool 5, it moves relatively along the axis AA of the tubular body 1. Here, the axis B-B, which is the rotation axis of the female tool 5, is parallel to the axis A-A, which is the rotation center axis of the tubular body 1 supported by the chuck 3A, for a predetermined distance S (see FIG. 3). Misaligned (eccentric). For example, the predetermined distance S is set to a value that can appropriately perform the aperture restriction and sealing at the end of the tube 1 (perform appropriate processing).

  The female tool 5 is formed in a stepped columnar shape including a small diameter portion 6 and a large diameter portion 7. Among these, the small diameter part 6 is supported by the tool stand which is not shown in figure. Here, the tool table is provided with a drive motor (not shown) for rotationally driving the female tool 5, and the female tool 5 rotates the tube 1 around the axis BB by this drive motor. It rotates (spins) in the same direction as the direction. Further, the tool table can be moved along the axis AA of the tube 1 (the axis BB of the female tool 5), and the movement of the tool table allows the female tool 5 to be moved into the tube. 1 is configured so that it can be moved closer to or farther along the axis AA (axis BB).

  Also, the end surface of the large-diameter portion 7 (the surface facing the end portion of the tube body 1) is brought into contact with the end portion of the tube body 1 to form the end portion of the tube body 1 (with a mouthpiece and a seal) Performing) is provided with a molding recess 8. The molding concave portion 8 is roughly constituted by a molding introduction portion 8A having a partially conical concave shape, a bottom portion 8B having a substantially flat surface shape, and a curved portion 8C in which the molding introduction portion 8A and the bottom portion 8B are continuous.

  A mandrel 9 is inserted into the tube 1, and the mandrel 9 is formed from the inside of the tube 1 at the end of the tube 1 squeezed and sealed by the female tool 5. Here, the mandrel 9 rotates around the axis AA of the tube 1 during the closing process. The mandrel 9 is a molding convex portion 10, a relief portion 11, a rod insertion hole 12, and a gas flow hole which will be described later. 13 in general.

  Reference numeral 10 denotes a forming convex portion as a forming portion provided at the tip end portion (end portion on the side facing the female tool 5) of the mandrel 9, and the forming convex portion 10 is the final stage of the closing process. The inner bottom surface 1A1 is formed by abutting the inner side surface of the portion that becomes the bottom portion 1A, that is, the inner bottom surface 1A1. Here, the forming convex portion 10 is formed as a curved surface having a partial conical convex shape or a partial spherical convex shape.

  Reference numeral 11 denotes a relief portion 11 provided radially inward of the molding convex portion 10 in the tip portion of the mandrel 9. The relief portion 11 is located on the opposite side of the female tool 5 from the leading edge of the molding convex portion 10. It is formed as a concave substantially conical concave surface. Here, the relief portion 11 is a material (material) of a portion to be squeezed and sealed in the tube body 1 during the closing process, in other words, a material (material) squeezed to the inner diameter side in the tube body 1 ( Even when the amount of material is increased, excessive pressure is applied to the forming concave portion 8 of the female tool 5 and the forming convex portion 10 of the mandrel 9 due to part of the material (excess) entering the escape portion 11 (escape). This prevents the addition of.

  Reference numeral 12 denotes a rod insertion hole 12 provided in the mandrel 9. The rod insertion hole 12 extends along the axis AA of the mandrel 9, and inserts a pressure rod 15 described later. Here, the rod insertion hole 12 includes a small-diameter portion 12A that opens to a relief portion 11 provided at the tip of the mandrel 9, and a large-diameter portion 12B that is located on the side farther from the female tool 5 than the small-diameter portion 12A. The small-diameter portion 12A and the large-diameter portion 12B are formed as stepped holes provided with a continuous portion 12C that makes the continuous portion 12C continuous.

  13 is a gas flow hole provided in the mandrel 9. The gas flow hole 13 has one end opened to the outer peripheral surface of the mandrel 9 and the other end communicated with the large diameter portion 12B of the rod insertion hole 12. Yes. Here, in the gas flow hole 13, a gap formed by an inner peripheral surface of the large-diameter portion 12 </ b> B of the rod insertion hole 12 and a concave groove 15 </ b> D provided on an outer peripheral surface of a pressurizing rod 15 to be described later during the closing process. An inert gas such as nitrogen gas is sent through the passage 14. Then, the inert gas sent to the gas flow hole 13 through the gap passage 14 flows out to the outer peripheral surface side of the mandrel 9 through the gas flow hole 13, and the end of the tubular body 1 to be squeezed and sealed ( The portion processed into the bottom 1A) is prevented from being oxidized at the end.

  Reference numeral 15 denotes a pressure rod provided in the rod insertion hole 12, and the pressure rod 15 is axially moved along the axis AA of the mandrel 9 in the rod insertion hole 12 at the final stage of the aperture stop and sealing. The central portion (sealed portion) of the inner bottom surface 1A1 of the tube body 1 is pressurized by moving to.

  Here, the pressure rod 15 is formed in a stepped columnar shape having a small diameter portion 15A and a large diameter portion 15B, and a distal end surface 15C as a distal end pressure portion is a flat surface orthogonal to the axis AA. Further, a concave groove 15D for forming a gap passage 14 through which an inert gas flows is provided along the axis AA of the pressure rod 15 (axial direction) on the outer peripheral surface of the large diameter portion 15B. Yes.

  Further, as shown in FIGS. 1 and 2, the pressure rod 15 is arranged so that the tip surface 15C of the pressure rod 15 becomes the bottom surface of the escape portion 11, that is, the tip surface 15C of the pressure rod 15 is the relief portion. 11 is positioned with respect to the mandrel 9 so as to be positioned on the inner diameter side of the inner peripheral edge of the inner periphery. Then, when the central portion of the inner bottom surface 1A1 is pressurized using the pressure rod 15 at the final stage of the aperture stop and the sealing, as shown in FIG. It protrudes to the female tool 5 side from the inner periphery of the escape portion 11.

  That is, when pressure is applied by the pressure rod 15, the pressure rod 15 moves in the axial direction independently of the mandrel 9, and the tip surface 15C of the pressure rod 15 is the center of the inner bottom surface 1A1 of the tubular body 1. Abuts against the part. The pressure rod 15 presses the central portion of the inner bottom surface 1A1 with a predetermined pressure for a predetermined time, thereby applying a pressure necessary for appropriate bonding to the central portion of the inner bottom surface 1A1.

  In other words, the pressurizing rod 15 pressurizes the central portion of the inner bottom surface 1A1 by pressure control in which the pressurization time is set so that the central portion of the inner bottom surface 1A1 of the tubular body 1 is stably joined. It is configured. Then, as a result of such pressurization of the pressure rod 15, a concave portion 1B having a substantially flat bottom is formed at the center of the inner bottom surface 1A1 of the tube 1 as shown in FIG.

  Reference numeral 16 denotes a rod driving device for driving the pressure rod 15 in the axial direction along the axis AA of the mandrel 9. The rod driving device 16 includes a piston 16A connected to the pressure rod 15, and the piston 16A. And a cylinder 16B into which 16A is fitted. Then, based on the supply / discharge of the pressure oil to / from the rod driving device 16, the piston 16B is displaced in the axial direction within the cylinder 16A, whereby the pressure rod 15 is displaced in the axial direction independently of the mandrel 9, The front end surface 15C of the pressurizing rod 15 is configured to pressurize the central portion of the inner bottom surface 1A1.

  The closing processing apparatus 2 according to the present embodiment has the above-described configuration. Hereinafter, a closing processing method for the tubular body 1 using the closing processing apparatus 2 will be described with reference to the flowchart of the work procedure shown in FIG. To do.

  First, in step 1, the tube 1 is attached to the chuck 3 </ b> A of the chuck device 3 as shown in FIG. 1. Next, in step 2, the high frequency heating coil 4 is moved. That is, as shown in FIG. 1, the high frequency heating coil 4 is moved until the end of the tube 1 is inserted into the insertion hole 4 </ b> A of the high frequency heating coil 4.

  Next, in step 3, the mandrel 9 is positioned. That is, as shown in FIG. 1, a mandrel 9 is inserted into the tube 1, and a predetermined position (for example, a position suitable for molding a portion to be squeezed and sealed by the mandrel 9 from the inside of the tube 1). ) To fix the mandrel 9. At this time, the pressure rod 15 is inserted into the tubular body 1 together with the mandrel 9 with the distal end surface 15C positioned on the inner diameter side of the inner peripheral edge of the escape portion 11 (moves together with the mandrel 9). .

  Subsequently, as shown in step 4, the tube body 1 is rotated by the chuck device 3, and in the subsequent step 5, the rotating speed of the rotating tube body 1 is set to a predetermined speed (for example, suitable for performing aperture drawing and sealing). It is determined whether or not the speed is correct. If it is determined in step 5 that the rotational speed of the tube 1 is not a predetermined speed, the process returns to the position before step 5 and the rotational speed is determined again in step 5. The determination of the rotational speed in step 5 is repeated until the rotational speed of the tube 1 reaches a predetermined speed.

  On the other hand, if it is determined in step 5 that the rotational speed of the tube 1 is a predetermined speed, the process proceeds to the next step 6 where the high-frequency heating coil 4 is energized and the end of the tube 1 is heated. . Subsequently, it progresses to step 7, and returns the high frequency heating coil 4 to the initial position (position before the movement of the high frequency heating coil 4 by step 2 is started). At this time, the high-frequency heating coil 4 returns to the initial position after the temperature of the end portion of the tube body 1 reaches a predetermined temperature (for example, a temperature appropriate for performing mouth drawing and sealing). For this purpose, for example, a step of determining whether or not the temperature of the end portion of the tubular body 1 is a predetermined temperature can be provided between Step 6 and Step 7.

  If the high-frequency heating coil 4 is returned to the initial position in step 7 described above, the process proceeds to the next step 8 where the female tool 5 is advanced toward the end of the tube 1. That is, while rotating the female tool 5 relative to the rotating tubular body 1, the female tool 5 is advanced along the axis AA of the tubular body 1 (relative to the direction in which the female tool 5 and the tubular body 1 approach each other). Move). At this time, the female tool 5 is rotated (rotated) in the same direction as the tube 1.

  When the female tool 5 is advanced while rotating, first, the forming introduction portion 8 </ b> A of the forming recess 8 of the female tool 5 comes into contact with the end portion of the tubular body 1. And the opening peripheral part of the edge part of the pipe body 1 is gradually narrowed toward an inner diameter side by this contact and advance of the female tool 5. FIG. That is, as the female tool 5 advances, the end of the tube 1 is deformed in a direction of reducing the diameter along the concave surface of the forming recess 8 of the female tool 5, and the end of the tube 1 is changed to FIG. As shown in FIG.

  Such advancement of the female tool 5 is continued until a preset advance end (the most advanced position, for example, a position suitable for sealing) is reached (for example, until the state shown in FIG. 2 is reached). . That is, when the movement of the female tool 5 is started in step 8, the process proceeds to the subsequent step 9 to determine whether or not the female tool 5 is located at the forward end. If it is determined in step 9 that the female tool 5 is not positioned at the forward end, the process returns to the position before step 9, and the position of the female tool 5 is determined again in step 9. The determination of the position of the female tool 5 in step 9 is repeated until the female tool 5 is positioned at the forward end.

  If it is determined in step 9 described above that the female tool 5 is positioned at the forward end, the process proceeds to the subsequent step 10 and the pressure rod 15 is moved along the axis A- of the mandrel 9 as shown in FIG. Advance along A in a direction approaching the female tool 5. That is, as a final stage process of mouth-squeezing and sealing, the central portion of the inner bottom surface 1A1 of the tube body 1 is pressurized by the pressure rod 15. And this pressurization is comprised so that predetermined time (time required in order for the center part of the inner bottom face 1A1 of the tubular body 1 to be connected stably) may be performed.

  That is, if advancement of the pressure rod 15 is started in step 10, the process proceeds to step 11 to determine whether or not a predetermined time has elapsed since the advancement of the pressure rod 15 was started. If it is determined in step 11 that the predetermined time has not elapsed, the process returns to the position before step 11 and it is determined again in step 11 whether the predetermined time has elapsed. The determination in step 11 is repeatedly performed until a predetermined time has elapsed after the advancement of the pressure rod 15 is started.

  If it is determined in step 11 that a predetermined time has elapsed, the process proceeds to step 12, and the pressure rod 15 is moved to the initial position (position before starting the advancement of the pressure rod 15 in step 10). return. Next, the process proceeds to step 13 where the female tool 5 is returned to the initial position (position before starting the advancement of the female tool 5 in step 8), and then in step 14, the mandrel 14 is moved together with the pressure rod 15 together. Return to the initial position (position before the mandrel 9 is positioned in step 3). Then, the process proceeds to step 15, where the apertured and sealed tube body 1 (bottomed tube) is removed from the chuck 3 </ b> A of the chuck device 3 and the process is terminated.

  As described above, according to the first embodiment, the central portion of the inner bottom surface 1A1 of the tubular body 1 is pressurized by the pressure rod 15 at the final stage of the aperture stop and the sealing, so that the plate thickness of the tubular body 1 is increased. Even if the tolerance and the positioning accuracy of the tubular body 1 are not strictly regulated (even if the width of the projecting volume is widened), the sealing performance of the sealed portion (the bottom portion after processing) can be secured.

  That is, at the final stage of the aperture stop and sealing, the tip surface 15C of the pressure rod 15 comes into contact with the central portion of the inner bottom surface 1A1 of the tube body 1, and the central portion of the inner bottom surface 1A1 is pressurized. And by this pressurization, as shown in FIG. 4, a concave portion 1B having a substantially flat bottom is formed at the center of the inner bottom surface 1A1. And when the recessed part 1B is formed in this way, the pressure required in order to join appropriately in the said part is added to the center part of inner bottom face 1A1.

  On the other hand, even in the case of the prior art in which no pressurization by the pressurizing rod 15 is performed, the volume of the portion of the tubular body 1 to be squeezed and sealed, that is, the volume of the portion indicated by the two-dot chain line in FIG. By strictly controlling the volume V), an appropriate pressure is applied to the bottom 1A of the tubular body 1 by the molding concave portion 8 of the female tool 5 and the molding convex portion 10 of the mandrel 9, and the joining of the portion is performed. Can be performed properly. That is, for each process, if the thickness tolerance of the tube 1 and the positioning accuracy of the tube 1 with respect to the chuck 3A are strictly regulated so that the protruding volume V shown by the two-dot chain line in FIG. Appropriate pressure is applied to the bottom 1A of the tubular body 1 from the forming concave portion 8 of the female tool 5 and the forming convex portion 10 of the mandrel 9, and the portions are appropriately joined.

  However, in the case of such a conventional technique, if the protruding volume V deviates from the tolerance, an appropriate pressure may not be applied to the bottom portion 1A of the tubular body 1, and the joining of the portion may be inappropriate. That is, when the protruding volume V is insufficient due to, for example, the time-dependent change of the chuck 3A, the slipping of the chuck 3A, the wear of the female tool 5 or the mandrel 9, the variation in the plate thickness of the tube 1, etc. There is a possibility that sufficient pressure is not applied and sufficient bonding is not performed. Here, the bonding is called interfacial bonding by interdiffusion, and at the final stage of sealing, the surfaces (interfaces) to be bonded to each other are held for a certain period of time with appropriate pressure at a predetermined temperature. As a result, the molecules in the metal diffuse and proper bonding is performed.

  Therefore, in the present embodiment, even if the protruding volume V varies somewhat due to the pressurizing rod 15 pressing the central portion of the inner bottom surface 1A1 of the tube body 1 at the final stage of the aperture stop and sealing, the inner bottom surface The pressure required for proper joining is applied to the center of 1A1. For this reason, even if management of the protrusion volume V is not strict, proper bonding can be performed at the center of the inner bottom surface 1A1, and the sealing performance of the inner bottom surface 1A1 can be ensured. In other words, even if the control range of the protruding volume V is expanded, the sealing performance can be secured, so that the robustness can be obtained and the processing cost can be reduced.

  Next, FIG. 6 and FIG. 7 show a second embodiment of the present invention. The feature of this embodiment is that a recognition protrusion is provided on the tip pressure portion of the pressure rod. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, 21 is a pressure rod provided in the rod insertion hole 12, and this pressure rod 12 is used in this embodiment instead of the pressure rod 15 according to the first embodiment described above. is there.

  Reference numeral 22 denotes a tip pressing portion of the pressure rod 21, that is, a plurality of (three) recognition protrusions provided on the tip surface 21 A of the pressure rod 21. The front end surface 22A has a smaller area than the front end surface 21A. The marks are transferred to the central portion of the inner bottom surface 1A1 of the tubular body 1 by the respective recognition protrusions 22. Specifically, as shown in FIG. 7, as a mark corresponding to each recognition protrusion 22 is formed on the bottom of the recess 1 </ b> B formed on the inner bottom surface 1 </ b> A <b> 1 of the tubular body 1 by pressurization of the pressure rod 21. A recognition recess 1C is formed.

  The closing processing method and apparatus according to the present embodiment pressurize the central portion of the inner bottom surface 1A1 of the tube body 1 by the pressurizing rod 21 as described above, and the basic operation thereof is the first implementation described above. There is no particular difference from the form.

  However, according to the present embodiment, the marks are transferred to the central portion of the inner bottom surface 1A1 of the tubular body 1 by the respective recognition protrusions 22 provided on the distal end surface 21A of the pressure rod 21, that is, the recess 1B. Since the recognition recesses 1C are formed corresponding to the respective recognition protrusions 22 on the bottom of the, the recognition of whether or not the pressurization by the pressurizing rod 21 has been normally performed by this mark (recognition recess 1C). Can do. Further, the degree of wear at the tip of the pressure rod 21 can be known from the wear state of each recognition protrusion 22, and the amount used and the mold life can be known from this degree of wear. That is, each of the authentication protrusions 22 can be used as an index for determining the mold life, and the pressure rod 21, the female tool 5, and the mandrel 9 can be appropriately replaced.

  In the above-described embodiment, an example in which the axis BB serving as the rotation axis of the female tool 5 is made parallel to the axis AA serving as the rotation center axis of the tubular body 1 supported by the chuck 3A is taken as an example. And explained. However, the present invention is not limited to this. For example, as disclosed in Patent Document 1, the rotation axis of the female tool may be made non-parallel (tilted) with respect to the rotation center axis of the tubular body. .

  In the above-described embodiment, the case where the female tool 5 is moved toward the tube 1 during the closing process has been described as an example. However, the present invention is not limited thereto, and for example, the tube is moved during the closing process. It can also be moved towards the female tool. Further, at the time of closing, both the female tool and the tube can be moved in a direction approaching each other.

  Furthermore, in embodiment mentioned above, the case where the pipe body 1 (bottomed cylinder) by which the closing process was carried out is used as a cylinder (tube, base shell) which comprises the cylinder apparatus (buffer) for motor vehicles is mentioned as an example. explained. However, the present invention is not limited to this, and the tubular body (bottomed tube) may be used as a cylinder of a cylinder device used in, for example, railway vehicles, various machines serving as vibration sources, buildings, and the like. Moreover, it can be widely used not only as a cylinder device but also as a bottomed tube for various devices, machines, buildings, etc. using a bottomed tube.

  As described in the above embodiment, according to the invention of claim 1, since the inner bottom surface of the tubular body is pressurized by the pressure rod at the final stage of the aperture stop and the sealing, Even if the positioning accuracy of the tube body is not strictly regulated (even if the control range of the protruding volume is widened), the sealing performance of the sealed portion (the portion that becomes the bottom after processing) can be secured.

  According to the invention of claim 2, since the pressurizing time is set so that the inner bottom surface of the tubular body is stably joined, even if the protruding volume varies, the pressurizing rod is sealed by the pressurizing rod. Appropriate pressure can be applied to the part (the part that becomes the bottom after processing), and sealing can be performed stably.

  According to the invention of claim 3, since the mark is transferred to the inner bottom surface of the tubular body by the recognition protrusion provided at the tip of the pressure rod, has the pressure rod been normally pressed by this mark? You can recognize whether or not. Further, the degree of wear at the tip of the pressure rod can be known from the wear state of the recognition protrusion, and the amount used and the mold life can be known from the degree of wear. That is, the authentication protrusion can be used as an indicator for determining the mold life, and the pressure rod, the female tool, and the mandrel can be replaced appropriately.

  According to the invention of claim 4, since the pressure rod for pressurizing the inner bottom surface of the tubular body is provided in the rod insertion hole of the mandrel, the thickness tolerance of the tubular body and the positioning accuracy of the tubular body are strictly regulated. Even if it is not (even if the control range of the protruding volume is widened), it is possible to stably produce a bottomed cylinder in which the sealing performance of the portion to be sealed (the portion that becomes the bottom after processing) is ensured.

DESCRIPTION OF SYMBOLS 1 Tube 1A Bottom part 1A1 Inner bottom face 2 Closing processing apparatus 3 Chuck apparatus (rotating means)
4 High-frequency heating coil (heating means)
5 Female tool 9 Mandrel 10 Molding convex part (molding part)
12 Rod insertion hole 15, 21 Pressure rod 15C, 21A Tip surface (tip pressure part)
22 Recognizing protrusion

Claims (4)

The end of the tube is heated, and the female tool and the tube are moved relative to each other along the axis of the tube while rotating the female tool relative to the rotating tube. In the closing processing method of the tubular body that inserts a mandrel having a forming part into the female tool and performs mouth-drawing and sealing toward the female tool,
A closing method for a tubular body, wherein an inner bottom surface of the tubular body is pressurized by a pressure rod that moves in an axial direction along an axis of the mandrel at the final stage of the aperture drawing and sealing.   2. The tube closing method according to claim 1, wherein the pressurizing rod sets a pressurizing time so that the inner bottom surface of the tube is stably joined.   A recognition protrusion having a smaller area than the area of the tip pressure portion is provided at the tip of the pressure rod, and the mark is transferred to the inner bottom surface of the tubular body by the recognition protrusion. Or a method of closing a tubular body as described in 2 above. Rotating means for rotating the tubular body, heating means for heating the end of the tubular body, a female tool that moves relative to the rotating tubular body while rotating relative to the tubular body, and a tip And a mandrel that is inserted into the tube body and has a forming portion for forming the inner bottom portion of the tube body, and the mouth of the end portion of the tube body is moved relative to the female tool and the mandrel. In the tube closing processing device for drawing and sealing,
The mandrel is provided with a rod insertion hole extending along the axis, and the rod insertion hole is provided with a pressure rod that pressurizes the inner bottom surface of the tubular body by moving in the axial direction within the rod insertion hole. An apparatus for closing a tubular body.

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