JP6050963B2 - Inner tube manufacturing apparatus and inner tube manufacturing method - Google Patents

Description

  The present invention relates to an inner tube manufacturing apparatus and an inner tube manufacturing method for manufacturing an inner tube of a shock absorber used for a front fork or the like of a motorcycle, and more particularly to a method for correcting roundness.

  A shock absorber 100 is attached to the front fork of the motorcycle M (see FIG. 3). The shock absorber 100 is configured by combining an outer tube 110 and an inner tube 120. In the inner tube manufacturing method, a tube processed by core drawing from a raw tube is induction-quenched and tempered (furnace return / high frequency). At this time, the tube is deformed and the roundness is lowered. The amount of deformation at this time is about 0.1 to 0.3 mm when the outer diameter is, for example, 50 mm. In order to correct this deformation, an outer diameter grinding step is performed in which the outer circumference is ground to adjust the outer diameter.

Japanese Patent No. 4647964 JP 59-130633 A JP 2007-061894 A

  The above-described inner tube manufacturing method has the following problems. That is, since the outer peripheral surface is ground, the outer diameter is constant, but the thickness after grinding is not uniform. In addition, a grinding allowance in anticipation of the deformation amount is required, and the outer diameter of the raw tube is increased, and at the same time, the grinding process (number of times of grinding) is increased. In addition, the machining allowance becomes uneven, and scratches before grinding tend to remain, which may affect the function of the shock absorber.

  Accordingly, an object of the present invention is to provide an inner tube manufacturing apparatus and an inner tube manufacturing method that make the inner and outer diameters uniform and the grinding allowance uniform even for a tube that has undergone heat treatment and has reduced roundness. Yes.

  In order to solve the problems and achieve the object, the inner tube manufacturing apparatus and the inner tube manufacturing method of the present invention are configured as follows.

A support part that supports a tube made of a metal material, and a sphere made of a metal material that is disposed opposite to the support part, has an outer diameter larger than the inner diameter of the tube, and is harder than the material of the tube. A press-fitting portion to be passed , a hole portion having an inner diameter slightly larger than an outer diameter of the tube, a plurality of guide portions that guide the tube through the hole portion, and the plurality of guide portions. Ru Tei and a guide supporting portion juxtaposed supported along the axial direction of the tube.
A support part that supports a tube made of a metal material, and a sphere made of a metal material that is disposed opposite to the support part, has an outer diameter larger than the inner diameter of the tube, and is harder than the material of the tube. A press-fitting portion to be passed, a hole portion having an inner diameter slightly larger than an outer diameter of the tube, a plurality of guide portions that guide the tube through the hole portion, and the plurality of guide portions. A guide support portion that is arranged and supported along the axial direction of the tube, and the guide portion has a middle convex line connecting the centers of the plurality of holes.

A tube is formed by coreing the base tube, the tube is heat- treated, and after the heat treatment, the tube is placed along a plurality of annular guides, and the tube is placed outside the inner diameter of the tube. a metal material made of spheres having a diameter Ru is pressed-pass.
A plurality of annular guide portions formed such that a tube is formed by centering a base tube, the tube is heat-treated, and after the heat treatment, the tube is formed so that a line connecting the respective centers becomes a middle convex shape. The metal sphere having an outer diameter larger than the inner diameter of the tube is press-fitted and passed through the tube.

  According to the present invention, it is possible to produce an inner tube that is uniform in both inner and outer diameters and is less likely to leave scratches on the outer peripheral surface, even if it is a heat-treated tube.

The side view which shows typically the inner tube manufacturing apparatus which concerns on the 1st Embodiment of this invention. Explanatory drawing which expands and shows a partially broken main part of the inner tube manufacturing apparatus. The perspective view which shows typically the shock absorber apparatus with which the inner tube manufactured by the inner tube manufacturing apparatus was integrated. The graph which shows the internal diameter after an automatic correction before and after the ball sizing (press-fit process) of the inner tube manufactured with the inner tube manufacturing apparatus. The graph which shows the outer diameter before and after the ball sizing (press-fit process) of the inner tube manufactured by the inner tube manufacturing apparatus, and after automatic correction. The graph which shows the full length before and after the ball sizing (press-fit process) of the inner tube manufactured by the inner tube manufacturing apparatus, and after automatic correction. The graph which shows the runout (bending) before and after the ball sizing (press-fit process) of the inner tube manufactured by the inner tube manufacturing apparatus, and after automatic correction. The graph which shows the internal-diameter dimension and roundness after heat processing of the inner tube manufactured with the same inner tube manufacturing apparatus, and before ball | bowl sizing (press-fit process). The graph which shows the internal diameter dimension and roundness after ball sizing (press-fit process) of the inner tube manufactured with the inner tube manufacturing apparatus. The perspective view which shows typically the inner tube manufacturing apparatus which concerns on the 2nd Embodiment of this invention. Explanatory drawing which compares and shows the cross section before and after the ball sizing (press-fit process) of the inner tube manufactured with the inner tube manufacturing apparatus. Explanatory drawing which compares and shows the cross section before and after the ball sizing (press-fit process) of the inner tube manufactured with the inner tube manufacturing apparatus shown as a comparative example.

  FIG. 1 is a side view schematically showing an inner tube manufacturing apparatus 10 according to a first embodiment of the present invention, and FIG. 2 is an explanatory view showing a part E of FIG. FIG. 3 is a perspective view schematically showing the shock absorber device 100 in which the inner tube 120 manufactured by the inner tube manufacturing device 10 is incorporated. 4 to 7 are graphs showing measured values before and after ball sizing (press-fit processing) of the inner tube 120 by the inner tube manufacturing apparatus 10 and after automatic correction.

  As shown in FIG. 1, the inner tube manufacturing apparatus 10 includes a bottomed cylindrical support portion 11 that supports one end of a metal tube C, a cylindrical presser 15 that supports the other end of the tube C, The tube C is provided with a press-fitting portion 12 for press-fitting and passing a sphere D made of a metal material having an outer diameter larger than the inner diameter of the tube C and harder than the material of the tube C. The press-fit portion 12 includes a hydraulic cylinder 13 and a rod 14 that is operated by the hydraulic cylinder 13. A metal sphere D is detachably disposed at the tip of the rod 14. The spherical body D is formed of a metal harder than the material of the tube C and has an outer diameter slightly larger than the inner diameter of the tube C.

  FIG. 3 schematically shows a shock absorber 100 in which the inner tube 120 manufactured by the inner tube manufacturing apparatus 10 is used. That is, the shock absorber 100 is used for a front fork or the like of the motorcycle M, and the outer tube 110 and the inner tube 120 are arranged coaxially and configured to be slidable in the axial direction.

  The inner tube 120 is manufactured using the inner tube manufacturing apparatus 10 as follows. In the inner tube manufacturing method, the tube C is plastically processed by drawing the base tube. Next, a predetermined heat treatment such as induction hardening and tempering (furnace return / high frequency) is performed to form a metal structure. At this time, the tube is deformed and the roundness is lowered.

  Next, one end of the tube C is inserted into the opening of the support portion 11 of the inner tube manufacturing apparatus 10, and the other end surface is fixed by pressing the other end with the presser 15. Next, the sphere D is placed on the upper end of the tube C. Then, the hydraulic cylinder 13 is operated to extend the rod 14. Thereby, the sphere D is press-fitted into the tube C. The extension speed of the rod 14 is about 15 mm per second, for example. In this way, the sphere D is passed through the tube C to complete the process.

  Next, the shake (bend) of the tube C is corrected using an automatic bend straightening machine.

  Furthermore, grinding of the outer peripheral surface of the tube C, a flaw detection test, etc. are performed, and the inner tube 120 is completed.

  Here, it demonstrates based on the dimension of the concrete tube C and the inner tube 120, etc. FIG. For example, before heat treatment, a tube C having an axial length of 603 mm, an inner diameter of 45 mm, an outer diameter of 48.5 mm, and a wall thickness of 1.75 mm is used. Next, when heat treatment is performed, the inner diameter, outer diameter, total length, and runout change as shown in FIGS. Here, the runout is the amount of bending at the center measured on the basis of the outer diameter. I. R (Axial eccentricity: Total Indicator Reading).

  Next, using the inner tube manufacturing apparatus 10, a sphere D having a diameter of 48.5 mm is press-fitted into the tube C to correct the tube C, that is, perform ball sizing. After ball sizing, the inner diameter, outer diameter, total length, and runout change as shown in FIGS. That is, the inner and outer diameters are increased and the overall length is shortened. However, the same change does not occur with respect to runout, and it becomes larger or smaller. This is influenced by the initial bending amount after quenching.

  That is, the inner diameter, the outer diameter, and the total length are almost the same, the variation in the inner and outer diameter dimensions is eliminated, and the runout changes. Such a tendency is the same at both ends and the center of the tube C.

  FIG. 8 is a graph showing the inner diameter and roundness after heat treatment of the inner tube manufactured by the inner tube manufacturing apparatus 10 and before ball sizing (press fitting). FIG. 9 is manufactured by the inner tube manufacturing apparatus 10. 6 is a graph showing the inner diameter size and roundness after ball sizing (press-fit processing) of the inner tube.

  In this way, the tube C is heat-treated and then ball sizing (press-fit processing), thereby improving the roundness of the inner tube 120 and obtaining desired performance even when incorporated in the shock absorber 100. Can do.

  Moreover, since the machining allowance of the outer peripheral surface can be minimized, it is possible to save materials.

  FIG. 10 is a partially cutaway perspective view showing the inner tube manufacturing apparatus 20 according to the second embodiment of the present invention, and FIG. 11 is a cross-sectional view of the tube C before ball sizing and the inner tube manufacturing having the straightening apparatus 200. It is explanatory drawing which compares and shows the cross section of the tube C2 after performing ball sizing using the apparatus 20. FIG. FIG. 12 shows the tube C before and after ball sizing when ball sizing is performed using the inner tube manufacturing apparatus shown as a comparative example in order to explain the function of the inner tube manufacturing apparatus 20 according to the present embodiment. It is explanatory drawing which shows the cross-sectional shape of C3). 10 and 11, the same reference numerals are given to the same functional parts as those in FIG. 1, and detailed description thereof will be omitted.

  The inner tube manufacturing apparatus 20 according to the present embodiment includes a bottomed cylindrical support portion 11 that supports one end of a metal tube C, a presser 15 that supports the other end of the tube C, and the tube C. A press-fitting portion 12 for press-fitting and passing a sphere D made of a metal material having an outer diameter larger than the inner diameter of the tube C and harder than the material of the tube C, and a shape in which the tube C is deformed when the sphere D is press-fitted. The correction apparatus 200 is provided. The press-fit portion 12 includes a hydraulic cylinder 13 and a rod 14 that is operated by the hydraulic cylinder 13. In the present embodiment, a correction device 200 shown in FIG. 10 is added to the inner tube manufacturing apparatus 10 according to the first embodiment.

  The straightening device 200 includes guide portions 210a, 210b, 210c, 210d, 210e, and 210f that guide the tube C through the tube C, and a guide support portion 220 that supports the guide portions 210a to 210f. The guide portions 210a to 210f are formed in a flat plate shape, and include holes 211a, 211b, 211c, 211d, 211e, and 211f that have an inner diameter slightly larger than the outer diameter of the tube C. The guide support part 220 supports the guide parts 210a to 210f in a state in which the guide parts 210a to 210f are parallel to each other and arranged in parallel along the axial direction of the tube C. Moreover, the guide parts 210a-210f are hold | maintained in the state in which the center of each hole part 211a-211f is located on a circular arc. The arc is a kind of middle convex shape and may be a part of an elliptical shape.

  Using the inner tube manufacturing apparatus 20, the inner tube 120 is manufactured as follows. In the inner tube manufacturing method, the tube C is plastically processed by drawing the base tube. Next, a predetermined heat treatment such as induction hardening and tempering (furnace return / high frequency) is performed to form a metal structure. At this time, the tube is deformed and the roundness is lowered.

  Next, one end of the tube C is inserted into the opening of the support portion 11 of the inner tube manufacturing apparatus 20 and the other end surface is fixed by pressing the other end with the presser 15. At this time, the tube C is fixed in a state of passing through the holes 211 a to 211 f of the guide portions 210 a to 210 f of the correction device 200. Next, the sphere D is placed on the upper end of the tube C. Then, the hydraulic cylinder 13 is operated to extend the rod 14. Thereby, the sphere D is press-fitted into the tube C. The extension speed of the rod 14 is about 15 mm per second, for example. At this time, the outer diameter of the tube C is expanded by press-fitting, interferes with the guide portions 210a to 210f, and forms a shape defined in the correction device 200. Since the centers of the hole portions 211a to 211f are located on the arc, the guide portions 210a to 210f are also formed in a shape bent in an arc shape as indicated by C2 in FIG.

  Next, the arc-shaped run-out (bend) of the tube C is corrected using an automatic bend straightening machine.

  Furthermore, grinding of the outer peripheral surface of the tube C (C2), a deep damage test, etc. are performed, and the inner tube 120 is completed.

  When the inner tube is manufactured using the correction device 200 formed as described above, the following effects are obtained. That is, the tube C2 shown in FIG. 11 has a shape bent in an arc shape. On the other hand, the correction device 250 shown in FIG. 12 is fixed at a position where the centers of the holes 211a to 211f of the guide portions 210a to 210f pass on a straight line. When the straightening device 250 is used or when the straightening device is not used, a tube C3 having irregular runout is formed after ball sizing.

  Since the tube C2 formed using the straightening device 200 has a prescribed circular arc shape, the shake can be corrected more easily and more accurately than the tube C3 having an irregular runout.

  Therefore, according to the inner tube manufacturing apparatus 20 which concerns on this Embodiment, while being able to acquire the effect similar to the inner tube manufacturing apparatus 10 which concerns on 1st Embodiment, the ball sizing of the tube C using the correction apparatus 200 By intentionally defining the run-out (bending) of the time, it is possible to easily and accurately correct the run-out of the tube C, and to add an effect of improving the straightness of the axial center. In the inner tube manufacturing apparatus 20, the number of guide portions is six. However, in the present embodiment, the number of guide portions is not limited to six.

  As described above, according to the inner tube manufacturing apparatus of the present invention, it is possible to manufacture the inner tube 120 that is uniform in both inner and outer diameters and is less likely to leave scratches on the outer peripheral surface, even with the heat-treated tube C. Become.

The present invention is not limited to the foregoing embodiments and is given Ru course der various modifications may be implemented without departing from the scope of the present invention. Hereinafter, the invention described in the scope of claims of the present application will be appended.
[1] A support portion that supports a tube made of a metal material, and a metal member that is disposed opposite to the support portion, has an outer diameter larger than the inner diameter of the tube, and is harder than the tube material. An inner tube manufacturing apparatus comprising a press-fitting portion for press-fitting and passing a sphere.
[2] A hole portion having an inner diameter slightly larger than the outer diameter of the tube, a plurality of guide portions that guide the tube through the hole portion, and the plurality of guide portions in the axial direction of the tube And a guide support portion that supports the guide tube in parallel, and the guide portion is an inner tube manufacturing device according to [1] in which a line connecting the centers of the plurality of hole portions has a middle convex shape.
[3] A tube is formed by coreing the base tube, the tube is heat-treated, and a metal sphere having an outer diameter larger than the inner diameter of the tube is press-fitted and passed through the tube. Inner tube manufacturing method.
[4] After the heat treatment, before the press-fitting / passing of the sphere, the tube is installed along a plurality of annular guide portions formed so that the lines connecting the respective centers are in a convex shape. The method for manufacturing an inner tube according to [3], wherein

  DESCRIPTION OF SYMBOLS 10,20 ... Inner tube manufacturing apparatus, 11 ... Support part, 12 ... Press-fit part, 13 ... Hydraulic cylinder, 14 ... Rod, 15 ... Presser, 200, 250 ... Correction apparatus, 210a, 210b, 210c, 210d, 210e, 210f ... guide part, C, C2, C3 ... tube, D ... sphere.

Claims (4)

A support portion for supporting a tube made of a metal material;
A press-fitting part that is disposed opposite to the support part, has a larger outer diameter than the inner diameter of the tube in the tube, and press-fits and passes a sphere made of a metal material harder than the material of the tube ;
A plurality of guide portions having a hole portion having an inner diameter slightly larger than the outer diameter of the tube, and guiding the tube through the hole portion;
An inner tube manufacturing apparatus comprising: a guide support portion that supports the plurality of guide portions side by side along the axial direction of the tube. A support portion for supporting a tube made of a metal material;
A press-fitting part that is disposed opposite to the support part, has a larger outer diameter than the inner diameter of the tube in the tube, and press-fits and passes a sphere made of a metal material harder than the material of the tube;
Has a hole portion having a slightly larger inner diameter than the outer diameter of the upper Symbol tube, a plurality of guide portions for guiding passed through the tube to the hole,
A guide support portion that supports the plurality of guide portions side by side along the axial direction of the tube,
The guide portion, said plurality of holes, wherein the to Louis emissions donor tube manufacturing apparatus that line becomes a middle convex connecting the center of. Form the tube by centering the base tube,
Heat treating the tube,
After the heat treatment, the tube is installed along a plurality of annular guide portions,
A method of manufacturing an inner tube, comprising: pressing and passing a metal sphere having an outer diameter larger than the inner diameter of the tube into the tube. Form the tube by centering the base tube,
Heat treating the tube,
After top Symbol heat treatment, the upper Symbol tube, along the guide portion of the plurality of annular formed so that the line connecting the centers becomes middle convex installed,
The features and to Louis emissions donor tube manufacturing method Rukoto metal material made of a sphere having an inner diameter larger than the outer diameter of the tube is pressed-pass in the tube.

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