JP4370089B2 - Diameter expansion method and apparatus for expanding pipe member - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for expanding a pipe member that expands at least over a predetermined range in the axial direction of the pipe member, for example, a method for expanding a pipe member suitable for manufacturing a container for an exhaust system part for automobiles, and the like. Related to the device.
[0002]
[Prior art]
Various methods and apparatuses have been proposed for expanding the diameter of pipe members and for correcting the cross section of a steel pipe and correcting the cross-section (particularly rounding). (Kaihei 30-300069) and Japanese Patent Laid-Open No. 52-39566.
[0003]
In Patent Document 1 (Japanese Patent Laid-Open No. 8-300069), “in the method of expanding a metal tube, after performing the first tube expansion by a tube expansion tool element arranged in a substantially cylindrical shape and parallel to the tube axis direction, There is disclosed a method of expanding a metal tube, characterized in that a second expansion is performed by rotating a tube expansion tool element by a predetermined angle in the circumferential direction. Further, it is described that “the tool element can hit the entire range of the inner surface of the steel pipe by moving the steel pipe by a distance corresponding to the length of the tool axis in the direction of the pipe axis and sequentially expanding the pipe”.
[0004]
Further, Patent Document 2 (Japanese Patent Laid-Open No. 52-39566) states that “a pipe on a die head device that can be expanded radially with a pipe having a spiral weld seam and has a spiral groove on the surface of the die head. The spiral groove is provided so as to coincide with the spiral weld seam of the pipe that contacts the die head device, and the die head device in the pipe is expanded to gradually advance and rotate the pipe. , A method and apparatus for expanding a pipe that extends along the entire length of the pipe and is held such that the helical weld seam substantially coincides with the helical groove of the die head device. These techniques described in Patent Documents 1 and 2 perform pipe expansion and cross-sectional correction (rounding) on a thick and long steel pipe.
[0005]
On the other hand, regarding a processing method for expanding the diameter of a thin-walled tube, Patent Document 3 (Patent No. 2799106) states that “a cylindrical shape, a rod-shaped material, and a mold having a shape of a processing target shape are placed on the same center line. The materials and mold are pressed or contacted in the direction of the center line while applying high-speed fine vibration and rotation to one or both of the material and mold, and the material is drawn or expanded to the desired shape. A material drawing and expansion molding method "which is to be processed is disclosed.
[0006]
[Patent Document 1]
JP-A-8-300069
[Patent Document 2]
JP 52-39566 A
[Patent Document 3]
Japanese Patent No. 2799106
[0007]
[Problems to be solved by the invention]
By the way, in the exhaust system parts for automobiles such as recent mufflers and catalytic converters, in light of weight reduction and cost reduction, a metal container (casing) is formed with a thin plate thickness, and a necking portion is provided at the end. An integrally formed structure is becoming mainstream. In particular, it is required to expand a predetermined range of the raw tube to a predetermined diameter to form a body portion of the container, and to perform necking processing by spinning or the like on both end portions remaining as the raw tube. . That is, there is a demand for a technique for appropriately expanding the diameter up to a predetermined diameter over the entire length of the raw tube excluding both ends of the necking target.
[0008]
In this case, in the conventional diameter expansion method, the thin-walled pipe (for example, a SUS material having a thickness of around 1.0 mm) is further thinned (thickness is 1.0 mm or less) by the diameter expansion process. The limit on plastic working has been reached. For example, when an index for diameter expansion processing is represented by “thickness / diameter (t / D)”, the index is 0.01 to 0.0067 in the case of a diameter of 120 mm.
[0009]
In particular, a method of expanding the diameter at once by a so-called mechanical expander of a split type (collet type) is general, but according to this method, the diameter expansion range is reduced at once, so that the object to be processed is thin. In some cases, cracks and buckling may occur, and if the expanded diameter range becomes long, for example, if the expanded diameter range is several tens of centimeters or more in the axial length, which is necessary as an exhaust system part for automobiles, there is a risk of that. It gets bigger. In addition, even if the diameter can be expanded without causing problems by carefully expanding the diameter, it is unavoidable to have a polygonal cross section as long as it is compressed by a collet by a normal method. The cross-sectional shape cannot be ensured.
[0010]
Thus, there is a demand for the realization of a method and an apparatus capable of expanding a thin metal cylindrical member (thin tube) over a long range until it becomes a perfect circle having an arbitrary diameter. Particularly in automobile exhaust system parts, there is a strong demand for the outer cylinder (tube member) to be formed of a thin material and to have a uniform diameter expansion over the entire body portion excluding both ends (necking portions). Yes.
[0011]
In the above-mentioned Patent Document 1 (Japanese Patent Laid-Open No. 8-300069), an expander having a short axial length (width) is inserted into a raw steel pipe, diameter expansion processing is performed at an initial position, and the expander is closed slightly. Rotating (indexing) and performing diameter expansion processing again to make a perfect circle, and in the next process, the expander is moved in the axial direction and the same diameter expansion process is repeated. However, the pipe to which this method is applied is a steel pipe having a thickness of 7 mm or more, and even if the above-mentioned index (t / D) is close to the index of the exhaust system parts for automobiles, the limit in the diameter expansion plastic working Is different. That is, when the diameter of the steel pipe is expanded at the initial position, tapered portions are formed on both sides of the expander. In the next process, the tapered portion is subjected to plastic working again to form the expanded diameter portion. Multiple diameter expansion processes will cause the material to become brittle. In addition, the sequential diameter expansion processing with indexing for each expander width is difficult to shorten the processing time, so that it is not feasible as a mass production process for automobile exhaust system parts.
[0012]
On the other hand, in Patent Document 2 (Japanese Patent Laid-Open No. 52-39566), the diameter is expanded at the initial position, and the expander moves in the axial direction while rotating (indexing) as it is (opened). Therefore, the problems related to rounding and shortening of the processing time can be improved by spiral expansion. However, applying a pressure (compressive load) in the traveling direction during diameter expansion induces buckling in the processed part, so that it is difficult to apply to a thin-walled tube. Thus, the conventional pipe expansion and cross-section correction techniques for thick and long steel pipes cannot be applied to the diameter expansion processing of thin-walled pipes.
[0013]
On the other hand, as a processing method for expanding the diameter of a thin tube, there is a method described in Patent Document 3 (Patent No. 2799106). This is a diameter expansion processing only for the tube end, and a taper die for diameter expansion is inserted into the tube end. In doing so, diameter expansion processing is performed spirally over a certain range from the end of the tube by pressing and moving in the direction of the tube axis while applying high-speed fine vibration and rotation to the mold. However, this method is only a method of expanding (pushing out) the end of the tube, so that a compressive load is always applied to the thin tube in the axial direction, and the friction between the expanded portion and the mold (the expanded portion). There is a risk of inducing buckling in the enlarged diameter processed portion (tapered portion). In addition, the diameter can be expanded to a diameter determined by the mold, but beyond that, it is impossible, and the mold must be replaced when expanding to an arbitrary diameter. Naturally, it is also impossible to expand the diameter (central diameter expansion) over the entire body portion excluding both ends (necking portions) of the thin-walled tube.
[0014]
Furthermore, the above-described problems relating to the welded portion extending in the longitudinal direction of the pipe member formed from the plate material are also significant in the processing of the thin-walled pipe. Usually, the expansion ratio of the thin metal pipe is about 20%, but the expansion ratio of the welded portion is as low as about 5%. For this reason, it was necessary to set the diameter of the weld to be 5% or less. For example, in the above-described mechanical expander, since the elongation (diameter expansion ratio) of the material between the collets is large and the elongation of the material at the collet central portion is small, the weld is positioned at the circumferential central portion of the collet. The index management to be adjusted is necessary, and it is necessary to carry out the diameter expansion process little by little. As a result, the process is complicated and the processing efficiency is lowered.
[0015]
Therefore, the present invention provides a method for expanding the diameter of a tubular member that can expand the diameter of the tubular member so that the cross section is substantially a perfect circle over a predetermined range in the axial direction even if the tubular member to be processed is thin. The issue is to provide.
[0016]
In addition, the present invention provides a diameter expansion device for a pipe member that can expand the diameter of the pipe member so that the cross section is substantially a perfect circle over at least a predetermined range in the axial direction even if the pipe member to be processed is thin. Providing is another issue.
[0017]
[Means for Solving the Problems]
In order to solve the above-described problem, the diameter expansion method of the pipe member according to the present invention includes a plurality of diameter expansion members parallel to the tube axis of the pipe member to be processed, arranged in a cylindrical shape, Shi , Supports each expanded member so that it can move radially from the tube axis And a drive member that is slidably accommodated in the plurality of diameter-expanding members, and supports the drive member and each of the diameter-expanded members so as to be relatively movable in the axial direction. The diameter expansion tool is accommodated in the tube member, and at least one of the tube member and the diameter expansion tool is inserted into the tube in a state where the diameter expansion member is pressed against the inner surface of the tube member. Driving relatively to rotate about an axis, and relatively moving at least one of the tube member and the diameter expanding tool along the tube axis; According to the axial relative movement of the drive member and each of the enlarged member Each of the diameter-expanding members is driven while vibrating in the radial direction, and the diameter is expanded over at least a predetermined range in the axial direction of the pipe member.
[0018]
the above The diameter expansion method according to claim 1. , The drive member is moved axially with respect to the tube member while vibrating along the tube axis, and the plurality of diameter-expanding members are rotationally driven to integrally rotate the drive member, thereby expanding the expansion member. The radial member can be vibrated in the radial direction and driven in the radial direction.
[0019]
Further claims 1 In the diameter expansion method according to claim, 2 As described in the above, at least one of the tube member and the diameter expansion tool is relatively rotated around the tube axis in a state where each of the diameter expansion members is pressed against the inner surface of the tube member. And at least one of the tube member and the diameter expanding tool is relatively moved along the tube axis. According to the axial relative movement of the drive member and each of the enlarged member It is good also as expanding the diameter over the predetermined range of the axial direction of the said tube member by performing the process driven while vibrating each said diameter-expanding member in a radial direction several times.
[0020]
And the diameter expansion device of the pipe member of the present invention is the claim 3 As shown in the above, a plurality of expanded members parallel to the tube axis of the tube member to be processed Shi , Supports each expanded member so that it can move radially from the tube axis And a drive member that is slidably accommodated in the plurality of diameter-expanding members, and supports the drive member and each of the diameter-expanded members so as to be relatively movable in the axial direction. A diameter expanding tool, and the diameter expanding tool is housed in the tube member, and at least one of the tube member and the diameter expanding tool is in a state in which each diameter expanding member is pressed against the inner surface of the tube member. One is driven to rotate relative to the tube axis, and at least one of the tube member and the diameter expanding tool is relatively moved along the tube axis, According to the axial relative movement of the drive member and each of the enlarged member Drive means for driving each of the diameter-expanding members while vibrating in the radial direction and expanding the diameter over at least a predetermined range in the axial direction of the tube member is provided.
[0022]
Further claims 3 In the diameter expansion device according to claim 1, 4 As described above, in the state in which each of the diameter-expanding members is pressed against the inner surface of the tube member, the driving means is configured to move at least one of the tube member and the diameter-expanding tool relative to each other about the tube axis. And rotating at least one of the tube member and the diameter expanding tool relative to each other along the tube axis. According to the axial relative movement of the drive member and each of the enlarged member The step of driving each diameter-expanding member while vibrating in the radial direction may be performed a plurality of times to increase the diameter over a predetermined range in the axial direction of the tube member.
[0023]
Claims To 3 In the described diameter expansion device, the claim 5 As described above, the plurality of diameter-expanding members and the driving member are supported in a frictional contact state, and the driving means includes a rotation driving means that rotationally drives the plurality of diameter-expanding members, and the tube member. And an axial direction drive means for relatively moving the drive member along the tube axis, and with respect to the tube member while vibrating the drive member along the tube axis by the axial direction drive means. The drive member is relatively moved along the tube axis, and the plurality of diameter-expanding members are rotationally driven by the rotational driving means to rotationally drive the drive members integrally, and the diameter-expanding member is It may be configured to vibrate in the radial direction and to be driven in the radial direction.
[0024]
Further claims 5 In the diameter expansion device according to claim 1, 6 As described in the above, the plurality of diameter-expanding members are configured by a plurality of collets, and the drive member is slidably accommodated in the plurality of collets, and is a cone-shaped portion that is in frictional contact with the plurality of collets. It is preferable to support the draw bar so that the outer surface of the cone-shaped portion of the draw bar is in frictional contact with the inner surfaces of the plurality of collets.
[0025]
Further claims 6 In the diameter expansion device according to claim 1, 7 As described above, it is preferable that a pair of clamps for tightly gripping the outer periphery of both ends of the tube member is provided, and one clamp is driven to be close to the other clamp according to the movement of the draw bar.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described. First, the overall configuration of a pipe member diameter expanding apparatus according to an embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, an axial drive means 10, a rotation drive means 20, a diameter expanding tool 30 and a holding means 40 are disposed on the base 1 of the housing. The axial direction driving means 10 and the rotational driving means 20 constitute the driving means of the present invention, and the axial direction driving means 10 has a cone portion 31 (hereinafter simply referred to as a cone portion 31) at a tip portion and a driving member. The draw bar 32 is vibrated along the tube axis (the axis of the tube member W to be described later and extends in the horizontal direction in FIG. 1), and the draw bar 32 is driven in the horizontal direction in FIG. The draw bar 32 is configured to move relatively along the tube axis with respect to the two-dot chain line).
[0027]
Specifically, a ball screw 11 is supported on the base 1 so as to extend in the horizontal direction of FIG. 1, and a rotary cylinder 12 screwed into the ball screw 11 is supported on the base 1 so as to be movable. ing. The ball screw 11 is configured to be rotationally driven via a belt 14 by a servo motor 13 fixed on the base 1. The rotating cylinder 12 is configured to support the draw bar 32 so as to be rotatably driven and to vibrate the draw bar 32 in the horizontal direction of FIG. Thus, the rotating cylinder 12 moves along its axis in response to the rotation operation of the ball screw 11 while vibrating the draw bar 32.
[0028]
In addition, a motor 21 is fixed as a rotational drive means 20 to a support housing 2 fixed on the base 1, and the rotational force is transmitted to the chuck 23 via the V-belt 22. . The chuck 23 slidably supports the draw bar 32 and supports the collet 33 slidably together with the cover 24 in the radial direction, and rotates around the axis of the draw bar 32 (coaxial with the tube axis of the tube member W). Is supported by the support housing 2 so as to be able to rotate in the α direction of FIG. Incidentally, the rotary cylinder 12 and the servo motor 13 of the axial driving means 10 and the motor 21 of the rotational driving means 20 are driven and controlled by the controller CT.
[0029]
The diameter expansion tool 30 includes a plurality of diameter expansion members collets 33 parallel to the tube axis of the tube member W arranged in a cylindrical shape, and each collet 33 is supported so as to be movable in the radial direction from the tube axis. The cone part 31 of the draw bar 32 constituting the drive member is slidably accommodated in each collet 33. All the collets 33 have their rear ends bent in the radial direction, and the bent portions are slidably held by the cover 24. Thereby, each collet 33 can be moved in the radial direction (radial direction). The inner surface of each collet 33 is in frictional contact with the outer surface (tapered surface) of the cone portion 31, and when each collet 33 is rotationally driven in the α direction in FIG. The draw bar 32 in the contact state is integrally rotated. At this time, the draw bar 32 rotates in a driven manner, but the draw bar 32 is driven by the rotating cylinder 12 to vibrate at an early cycle (a specific example will be described later), and the draw bar 32 is connected to the ball screw 11 by the servo motor 13. Driven in parallel in the β or γ direction of FIG.
[0030]
That is, when the draw bar 32 is driven in the γ direction (right direction) in FIG. 1, each collet 33 moves (opens) while oscillating outward from the tube axis of the tube member W, and the diameter expanding step is performed. Conversely, when the draw bar 32 is driven in the β direction (left direction) in FIG. 1, each collet 33 moves (closes) while vibrating in the tube axis direction, which is a diameter reduction process. Thus, each collet 33 vibrates in the radial direction and is driven in the radial direction. A guide bar 34 is screwed to the tip of the draw bar 32 and is coaxial.
[0031]
On the other hand, the holding means 40 is arranged so as to face the above-described diameter expansion tool 30 and the like. That is, on the left side of FIG. 1, the ball screw 41 is supported by the base 1 so as to extend in the horizontal direction (parallel to the ball screw 11), and the moving base 42 that is screwed into the ball screw 41 is 1 is supported so as to be movable. The ball screw 41 is configured to be rotationally driven via a belt 44 by a servo motor 43 fixed on the base 1. Thus, the moving base 42 moves along its axis in accordance with the rotation operation of the ball screw 41.
[0032]
A clamp 45 is fixed to the moving base 42, and a rail 49 is fixed in parallel with the ball screw 41, and a clamp 46 is disposed so as to be movable on the rail 49. Further, a holder 47 that moves integrally with the clamp 46 is disposed on the opposite side of the clamp 45. The clamp 46 and the holder 47 can be advanced and retracted by a cylinder 48 fixed to the moving base 42. The cylinder 48 is controlled by a controller CT together with a servo motor 43, a clamp 46, an opening / closing device (not shown) for the holder 47, and the like.
[0033]
The holder 47 allows the guide bar 34 to move in the axial direction and prevents the movement (blurring) in the radial direction in order to prevent shaft blurring when the draw bar 32 is cantilevered and processed. Note that the holder 47 is not essential, and may be appropriately provided according to the support state during processing of the pipe member W.
[0034]
The clamps 45 and 46 of this embodiment are closely attached to the outer periphery of both ends of the pipe member W, and are divided into two parts by a plane parallel to the rail 49 (for example, a vertical plane). However, other clamping devices may be used. Although both ends of the pipe member W are firmly held by these clamps 45 and 46 as shown in FIG. 3, adjustments such as indexing at the time of clamping and processing with respect to the welding position of the pipe member W are not necessary.
[0035]
As will be described later, when the diameter of the pipe member W is increased, if the clamp 46 is driven close to the clamp 45 by the cylinder 48, an axial compressive load is applied to the pipe member W. Thereby, the plastic flow of the axial direction with respect to the pipe member W is accelerated | stimulated, and thickness reduction at the time of diameter expansion can be prevented.
[0036]
Thus, according to this embodiment, the diameter expanding tool 30 is relatively moved so as to be accommodated in the pipe member W, and each collet 33 is pressed against the inner surface of the pipe member W. Each collet 33 is radiated by being driven to rotate about the axis (tube axis) of the member W and moving along the tube axis by driving the diameter expanding tool 30 relative to the tube member W in the axial direction. The tube member W can be driven while being vibrated in the direction, and the pipe member W can be expanded to a predetermined diameter over at least a predetermined range in the axial direction. Hereinafter, as a specific example, in the case of forming a diameter-enlarged portion with an inner diameter of 120 mm in three passes over a predetermined range (axial distance L) of the central portion of a workpiece of a tube member W with an inner diameter of 102 mm. The operation will be described. In addition, although illustration is abbreviate | omitted, in the state which pressed each collet 33 to the inner surface of the pipe member W, by rotating the pipe member W with respect to the diameter expansion tool 30, it rotates relatively around a pipe axis. You may comprise. Further, during the diameter expansion process, the tube member W may be axially driven with respect to the diameter expansion tool 30 so as to be relatively moved along the tube axis.
[0037]
First, the clamps 45 and 46 firmly hold both end portions (non-diameter expanded portions) of the tube member W. These are driven by the servo motor 43 in the direction of the rotary cylinder 12 (to the right in FIG. 1) and stopped at the start position shown in FIG. At this time, the cone portion 31 of the draw bar 32 is arranged on the left side in the tube member W as shown in FIG. 2, and the collets 33 are in a state of being close to each other (closed state). Is disposed at the machining start position. The relationship between the pipe member W in this state and each collet 33 is shown in an enlarged manner in FIG.
[0038]
In the state of FIG. 3, the collet 33 is driven to rotate at 100 rpm by the motor 21, and the draw bar 32 is driven to vibrate in the axial direction (β and γ directions) at a predetermined frequency (33 Hz) by the rotating cylinder 12. The That is, the frequency at which the collet 33 vibrates 20 times with a stroke (amplitude) of 1 mm in the radial direction while the collet 33 (and the draw bar 32) in frictional contact with the cone portion 31 of the draw bar 32 makes one rotation in the α direction (33 Hz). ) And a minute vibration of 33 Hz / mm is applied to each collet 33. In this case, each collet 33 may be inserted into the pipe member W while being rotated and vibrated and disposed at a predetermined start position. In FIG. 3, the collet 33 is in contact with the inner surface of the tube member W. However, in actuality, the collet 33 is disposed so as to be in contact with or close to the inner surface of the tube member W as shown in FIG. Then, the pipe member W is arranged so as not to give a diameter expansion force.
[0039]
In the diameter expansion process of the present embodiment, the diameter is increased by 9 mm in 3 passes (one reciprocation + one time in one way), so the diameter is increased by 3 mm per pass. That is, the diameter is increased from the initial radius 51 mm to the radius 54 mm in the first pass, the radius 57 mm in the second pass, and the target radius 60 mm in the third pass. In FIGS. 3 to 5, the amount of diameter expansion is exaggerated for easy understanding. First, in the initial position, the collet 33 is vibrated and rotated while the outer diameter of the collet 33 is 100 mm (101 mm−amplitude). When the collet 33 is gradually moved (opened) in the radial direction until it reaches 107 mm, the diameter of the tube member W is increased from the inner diameter of 102 mm to the inner diameter of 108 mm. When the spring back of the pipe member W is large, the collet 33 is moved (opened) until the outer diameter becomes 107 mm or more so that an inner diameter of 108 mm is obtained as a result of the spring back (reduced diameter). Also good.
[0040]
When the expansion of the tube member W to the inner diameter of 108 mm is completed at the initial position, the axial distance L (see FIG. 5) is maintained along the tube axis while maintaining the outer diameter of the collet 33 while vibrating and rotating each collet 33 as it is. The movement of the first path is completed when the movement is performed by the distance indicated by 5. Next, at the end position of the first pass, the outer diameter of the collet 33 is enlarged from 107 mm to 113 mm, and in this state, the same diameter expansion processing is performed, and when the inner diameter of the tube member W becomes 114 mm, two passes The eye expansion is completed. Further, the outer diameter of the collet 33 is expanded from 113 mm to 119 mm, and in this state, the same diameter expansion processing is performed, and the inner diameter of the tube member W becomes a target of 120 mm, and the expanded diameter portion extending over the axial length L. Is formed, the third-pass diameter expansion is completed, and the state shown in FIG. 5 is obtained.
[0041]
Thereby, the diameter expansion is completed, and the diameter expansion pipe P having a substantially perfect cross section is formed. Thereafter, the rotation and vibration of the collet 33 are stopped or the rotation and vibration are maintained, and the movement base 42 is driven backward by the servo motor 43, and the diameter-expanded pipe P is detached from the collet 33. In addition, the time required for each pass in the diameter expansion process (that is, the movement time) is preferably about 5 seconds. The diameter expansion rate in each pass is preferably 5% or less.
[0042]
Thus, the plastic flow during diameter expansion is smoothly and uniformly performed in the circumferential direction and the axial direction. As a result, the diameter expansion processing index (t / D) is 0.01 or less, and even about a thin-walled tube member that is difficult to expand, it is about 20% (same as a normal plate thickness tube member). Not only can the diameter be increased, but also the thickness of the processed portion is smooth and uniform both in the circumferential direction and in the axial direction.
[0043]
The above-described embodiment is merely an example, and various numerical values (parameters) may be appropriately set according to the material and the processing state. Moreover, it is not limited to the apparatus of FIG.1 and FIG.2, A various structure is employable. Even in the above embodiment, a diameter-enlarged portion having a smooth and uniform plate thickness can be formed. However, in the case of higher accuracy, an outer mold that restrains from the outside of the enlarged-diameter portion is used in the final pass. Also good.
[0044]
Further, in the above embodiment, the diameter of the central part is expanded while leaving both ends of the pipe member W. However, the diameter may be increased over the entire length, or all other parts may be left with only one end. It is good also as expanding a diameter. For example, a catalyst carrier and a holding member are inserted (press-fit) from at least one end portion of the non-diameter portion, and then a necking portion is formed integrally or separately at at least one end portion. A purification device such as a converter or a DPF (diesel particulate filter) can also be configured. The final product is not limited to automobile exhaust system parts, but can be applied to various fluid treatment devices such as a fuel cell reformer.
[0045]
In particular, the so-called “diameter sizing” is possible by the highly accurate diameter expansion by the diameter expansion method of the present invention, and the subsequent press-fitting and holding of the catalyst carrier can be achieved with high precision. Further, the diameter expansion method of the present invention is suitable for forming a necking portion by spinning for the non-diameter expanded portions at both ends after the diameter expansion, and forming a muffler for an automobile with a thin tube made of SUS. . At this time, if a diameter expansion ratio of about 20% is secured by the diameter expansion method of the present invention and a diameter reduction ratio of about 20% is secured by spinning at both ends, apparently a diameter expansion of 40%. The ratio (reduction ratio) was obtained. That is, such a diameter expansion rate (diameter reduction rate) can be achieved only by plastic working on the tube material, and the effect of this is extremely great. The present invention is not limited to the case of expanding the diameter of a cylindrical tube material, but can also be applied to the case of expanding the diameter of the center of an intermediate processed product with one end processed. It is a thing.
[0046]
【The invention's effect】
Since this invention is comprised as mentioned above, there exists an effect as described below. That is, claim 1 And 2 In the method for expanding the diameter of the pipe member described in the above, each diameter-expanded member is driven while being vibrated in the radial direction, and the diameter can be increased over at least a predetermined range in the axial direction of the pipe member. Even if the tube member is thin, the diameter of the tube member can be increased so that the cross section becomes a substantially perfect circle over a predetermined range in the axial direction.
[0047]
Claims 3 and 4 In the pipe member diameter expanding device described in the above, the respective diameter expanding members are pressed against the inner surface of the pipe member and are driven by the driving means while vibrating each diameter expanding member in the radial direction. Since the diameter of the pipe member to be processed is thin, the tube has a substantially circular cross section over the predetermined range in the axial direction. The member can be expanded in diameter.
[0048]
Claims 5 as well as 6 If configured as described above, each of the diameter-expanding members can be driven while being vibrated in the radial direction easily and appropriately by the rotational driving means and the axial driving means. Further claims 7 If one clamp is driven close to the other clamp according to the movement of the draw bar, the plastic flow in the axial direction with respect to the pipe member is promoted, and the plastic flow during diameter expansion is Smoothly and uniformly in the direction and axial direction.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a pipe member diameter expanding apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a diameter expansion processing start state in the pipe member diameter expansion apparatus according to the embodiment of the present invention.
FIG. 3 is an enlarged cross-sectional view showing the relationship between the pipe member at the diameter expansion start position and the diameter expansion tool in the pipe member diameter expansion device according to an embodiment of the present invention.
FIG. 4 is an enlarged cross-sectional view showing the relationship between a pipe member and a diameter-expansion tool in the middle of diameter expansion processing in the diameter expansion device for a pipe member according to an embodiment of the present invention.
FIG. 5 is an enlarged cross-sectional view showing the relationship between the pipe member and the diameter-expanding tool after completion of the diameter-expansion processing in the pipe member diameter-expansion device according to one embodiment of the present invention.
[Explanation of symbols]
1 base, 10 axial drive means, 12 rotating cylinder,
20 rotation drive means, 21 motor, 24 cover,
30 diameter expansion tool, 31 cone shaped part, 32 draw bar,
33 collets, 40 holding means, 45, 46 clamps,
W pipe member, CT controller

Claims (7)

A plurality of diameter-expanding members parallel to the tube axis of the pipe member to be processed are arranged side by side in a cylindrical shape, and each diameter-expanding member is supported so as to be movable in the radial direction from the tube axis . The pipe member includes a drive member that is slidably received, and supports the drive member and each of the diameter-expanded members so as to be axially movable relative to each other. In a state where the respective diameter-expansion members are pressed against the inner surface, at least one of the tube member and the diameter-expansion tool is driven to rotate relative to the tube axis, and the tube member and the While relatively moving at least one of the diameter expansion tools along the tube axis, and vibrating each diameter expansion member in the radial direction in accordance with the relative axial movement of the drive member and each diameter expansion member Drive and expand the diameter over at least a predetermined range in the axial direction of the tube member How diameter of the pipe member, wherein the door. While driving each of the diameter-expanding members in contact with the inner surface of the tube member, at least one of the tube member and the diameter-expansion tool is driven to rotate relative to the tube axis; The axial distance of the predetermined range of the said pipe member is moved relative to at least one of the said pipe member and the said diameter expansion tool along the said pipe axis, and the axial direction relative of the said drive member and each said diameter expansion member is carried out a step of driving while oscillating in the radial direction of the enlarged diameter member of said each according to the movement performed a plurality of times, according to claim 1, wherein the diameter increases over a predetermined range in the axial direction of the pipe member Diameter expansion method for pipe members. A plurality of diameter-expanding members parallel to the tube axis of the pipe member to be processed are arranged side by side in a cylindrical shape, and each diameter-expanding member is supported so as to be movable in the radial direction from the tube axis . A drive member that is slidably received, and a diameter- expanding tool that supports the drive member and each diameter- expanding member so as to be axially movable relative to each other, and the diameter- expanding tool is accommodated in the tube member. Driving at least one of the tube member and the diameter expansion tool so as to rotate relative to the tube axis, with the respective diameter expansion members pressed against the inner surface of the tube member; At least one of the tube member and the diameter expanding tool is relatively moved along the tube axis, and each diameter expanding member is radiated in accordance with the axial relative movement of the drive member and each diameter expanding member. Drive while vibrating in the direction, over at least a predetermined range in the axial direction of the pipe member Diameter device of the tube member, characterized in that a drive means for enlarged Te. The drive means rotates at least one of the tube member and the diameter expansion tool relative to each other about the tube axis in a state where the respective diameter expansion members are pressed against the inner surface of the tube member. While driving, the axial distance of the said pipe member of the predetermined range moves relatively at least one of the said pipe member and the said diameter expansion tool along the said pipe axis, and the said driving member and each said diameter expansion member In accordance with the relative movement in the axial direction, the step of driving each of the diameter-enlarged members while vibrating in the radial direction is performed a plurality of times, and the diameter is increased over a predetermined range in the axial direction of the tube member. The diameter expansion device of the pipe member according to claim 3 characterized by things. The plurality of diameter-expanding members and the driving member are supported in a frictional contact state, and the driving means includes rotational driving means for rotationally driving the plurality of diameter-expanding members, and the driving member with respect to the tube member. Axial drive means for relatively moving along the tube axis, and oscillating the drive member along the tube axis by the axial drive means while moving the drive member with respect to the tube member. The plurality of diameter-expanding members are rotated relative to each other along the axis, and the plurality of diameter-expanding members are rotationally driven by the rotational driving means to integrally rotate the driving members, and the diameter-expanding members are vibrated in the radial direction. The pipe member diameter expanding device according to claim 3 or 4 , wherein the pipe member is configured to be driven in a radial direction. The plurality of diameter-expanding members are a plurality of collets, and the driving member is slidably accommodated in the plurality of collets, and includes a draw bar having a cone-shaped portion that is in frictional contact with the plurality of collets, 6. The diameter expansion device for a pipe member according to claim 5, wherein an outer surface of the cone-shaped portion of the draw bar is supported so as to be in frictional contact with inner surfaces of the plurality of collets. Claim 6, wherein the tube includes a pair of clamps for gripping and respectively close contact with the outer periphery of the end portions of the member, is driven to close one of the clamp in accordance with the movement of the drawbar to the other clamp The diameter expansion apparatus of the pipe member of description.

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