JP2016175111A - Spring forming machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spring molding machine capable of suppressing a manufacturing cost of a core metal.SOLUTION: A spring molding machine molds a coil spring 91 from a wire 90 so as to surround a core metal 20 projected out from a supporting wall 11, and cuts off the coil spring 91 from the following wire 90 by clipping the wire 90 with a cutting edge 16E of a cutting tool 16 and a cutting edge 24 of the core metal 20. On the supporting wall 11, a supporting hole 12 of a circular cross section is formed, and the core metal 20 is equipped with a round-rod stem portion 20L fitted with the supporting hole 12 and having a circular cross section, and a cantilever beam portion 20K projected out from the supporting wall 11 in a cantilever-shape, and having size stored within a cylindrical surface made by extending an outer peripheral surface of the round-rod stem portion 20L. The cutting edge 24 is disposed within a virtual plane surface 20M including a center line 20C of the round-rod stem portion 20L of the cantilever beam portion 20K.SELECTED DRAWING: Figure 2

Description

  The present invention forms a coil spring from a wire rod so as to surround a core bar protruding from a support wall, and the coil spring is separated from the subsequent wire rod by sandwiching the wire rod between the cutting edge of the cutting tool and the cutting edge of the core rod. The present invention relates to a spring molding machine.

  The core metal of this type of spring forming machine is generally formed by cutting the tip end side of a square member having a square cross section into a cantilever portion having a cross section shape (for example, a semicircular cross section or a polygonal cross section) with a sharp upper side ( For example, see Patent Document 1).

Japanese Patent No. 2534843 (FIG. 3, paragraph [0023])

  By the way, in the above-described conventional spring forming machine, the upper corner portion of the square bar, which is the base material of the core metal, is used as the cutting edge portion at the upper end of the cantilever portion. Here, when the metal core is disposed inside the coil spring with the square bar remaining and one corner of the square is directed to the inner peripheral surface of the coil spring, the other upper corner of the square bar becomes the inner peripheral surface of the coil spring. Will interfere. In order to avoid this, as described above, the tip end side of the core bar is cut out into a cantilever portion having a cross-sectional shape with the upper side pointed from the square bar.

  However, the square bar, which is the base material of the cored bar, has a flat upper surface, so it takes time to cut out from the square bar to a cantilever part having a sharp cross section on the upper side. It takes a great deal of work to cut out the semi-circular cantilever beam section. For this reason, it has been a problem that the manufacturing cost of the core metal becomes high. In addition, the cored bar is a consumable item, and there are cases where a plurality of types of cored bars must be provided in accordance with the coil diameter and the wire diameter of the coil spring.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a spring forming machine capable of suppressing the manufacturing cost of a cored bar.

  In order to achieve the above object, the invention according to claim 1 is characterized in that a coil spring is formed from a wire so as to surround a core bar protruding like a cantilever from a support wall, and the core bar is cut from the side. A spring forming machine for cutting the coil spring from the subsequent wire rod by sandwiching the wire rod between the cutting edge of the tool and the cutting edge of the metal core, and a support hole having a circular cross section formed in the support wall A round bar stem portion having a circular cross section provided on the core bar and fitted into the support hole; and an outer peripheral surface of the round bar stem portion provided on the core bar and protruding in a cantilever shape from the support wall. A cantilever portion having a size that can be accommodated in a cylindrical surface that extends and a cored bar fixing means for fixing the round bar stem portion to the support hole, and the center line of the round bar stem portion of the cantilever portion Near-virtual in the virtual plane containing or shifted to the vicinity from the virtual plane A spring forming machine that contains the cutting edge in a plane.

  According to a second aspect of the present invention, the cantilever part is formed by forming a notch in a round bar body concentric with the round bar trunk, and the notch is the virtual plane including the cutting edge or the vicinity thereof. It has a center cut surface that overlaps the virtual plane, and has a shape that excludes one side portion of the center cut surface from the round bar, and an intersection of the center cut surface and the outer peripheral surface of the round bar The spring forming machine according to claim 1, further comprising the cutting edge.

  According to a third aspect of the present invention, the center cut surface intersects at one place in the circumferential direction of the outer peripheral surface of the round bar body, and the opposite side of the cutting edge of the center cut surface is the outer periphery of the round bar body. It is a spring forming machine of Claim 2 located inside a surface.

  According to a fourth aspect of the present invention, an inclined edge portion that gradually approaches the cutting edge as the distance from the tip of the cantilever portion is provided on the opposite side of the cutting edge of the central cut surface. A spring forming machine according to claim 3.

  A fifth aspect of the present invention is the spring forming machine according to the third or fourth aspect, wherein the notch portions are arranged in a plane symmetry with respect to the cantilever portion.

  A sixth aspect of the present invention is the spring forming machine according to the third or fourth aspect, wherein a plurality of the cutout portions are formed in a state of being rotationally moved to a plurality of positions around the center line of the cantilever portion.

  The invention according to claim 7 is characterized in that the cantilever part has a tapered part gradually reduced in diameter from the round bar trunk part toward the front side, and a main body part having the notch part extending forward from the tip of the tapered part. The spring forming machine according to any one of claims 2 to 6, comprising:

  According to an eighth aspect of the present invention, as the core metal fixing means, a tightening ring that is fitted to the round bar stem, is deformed in a reduced diameter and is frictionally fixed to the core metal, and the tightening ring is attached to the support wall. A ring fixing portion that is fixed so that it cannot rotate and cannot move linearly, an outer peripheral tapered surface formed on the outer peripheral surface of the tightening ring, and is fitted to the outer side of the tightening ring so as to contact the outer peripheral tapered surface The outer taper member having an inner peripheral tapered surface, and a propulsion mechanism for moving and holding the outer taper member in a direction of deepening the fitting with the fastening ring. The spring forming machine according to claim 1.

  A ninth aspect of the present invention is the spring forming machine according to any one of the first to eighth aspects, wherein a key for key-connecting the support hole and the cored bar is provided as the cored bar fixing means. It is.

  In the spring forming machine according to claim 1, the portion of the core metal that is fitted into the support hole of the support wall forms a round bar trunk with a circular cross section and protrudes in a cantilever shape from the support wall of the core metal. The portion is a cantilever portion having a size that fits within a cylindrical surface obtained by extending the outer peripheral surface of the round bar trunk and having a cutting edge. Thereby, a metal core can be easily manufactured from a round material. Here, when the cored bar is placed inside the coil spring with the round bar or the round bar thinly cut with a lathe, it contacts only at one place in the circumferential direction with respect to the inner circumferential surface of the coil spring. Will do. Therefore, if the cutting edge is formed at or near the contact point, the core can be manufactured easily and in a short time compared to the case of manufacturing the core from square bar as in the past. Further, the core bar manufactured as described above has a structure having cutting edges in a virtual plane including the center line of the round bar trunk or in a neighboring virtual plane that is shifted to the vicinity from the virtual plane. In other words, the cored bar according to the present invention having a structure with a cutting edge in a virtual plane including the center line of the round bar trunk or in a neighboring virtual plane shifted to the vicinity from the virtual plane is easier and It can be manufactured in a short time, and the manufacturing cost can be reduced. Further, since the support hole formed in the support wall also has a circular cross section corresponding to the cored bar, it can be formed easily and in a shorter time than a conventional support hole having a square cross section.

  In addition, the cantilever part of the core bar may have a polygonal cross section, and has a structure in which a notch part is formed in a round bar body concentric with the round bar trunk part as in the configuration of claim 2. Also good. Further, the center cut surface of the notch may be crossed at two places in the circumferential direction of the round bar, and the cutting edge may be provided at two places in the circumferential direction. The center cutting surface may intersect at one place in the circumferential direction of the round bar, and the cutting edge may be provided at one place in the circumferential direction. According to the structure of Claim 3, compared with what the center cut surface of a notch cross | intersects in two places of the circumferential direction of a round bar, the intensity | strength of a metal core becomes high and it does not require the effort of manufacture.

  The cored bar of the configuration of claim 4 can easily form the notch by moving the rotary cutting tool so as to cross obliquely with respect to the tip of the round bar.

  In the structure of Claim 5, since the notch part is arrange | positioned and it is arrange | positioned in the plane symmetry of the cantilever part, it changes and uses a core metal from one notch part to the other notch part. Thereby, the direction of the to-be-cut surface in a coil spring can be changed into a reverse direction.

  In the configuration of claim 6, since the plurality of notches are formed so as to rotate and move to a plurality of positions around the center line of the cantilever portion, if the cutting edge of one notch is worn or damaged, the core The gold can be rotated to change to a cutting edge at another notch.

  In the structure of Claim 7, since the cantilever part is equipped with the main-body part which has the notch part in the front-end | tip of the taper part gradually diameter-reduced from the round bar trunk part, it uses for cutting | disconnection of a coil spring with a small diameter. be able to.

  According to the configuration of the eighth aspect, the tightening ring is frictionally fixed to the mandrel by moving the outer tapered member in the direction of deepening the fitting with the tightening ring by the propulsion mechanism. The tightening ring is fixed to the support wall by a ring fixing portion. As a result, the cored bar is fixed to the support wall via the clamping ring.

  According to the structure of Claim 9, rotation of a metal core can be reliably prevented with a key.

The perspective view of the spring molding machine which concerns on 1st Embodiment of this invention. Perspective view of cored bar Side sectional view of the core support part of the support wall Cross section of cored bar and cutting tool The perspective view of the metal core of 2nd Embodiment The perspective view of the cored bar of 3rd Embodiment (A) Perspective view of the cored bar of the fourth embodiment, (B) Perspective view of the cored bar of the fifth embodiment Side sectional view of a cored bar support part of a support wall according to a sixth embodiment (A) Front view of cored bar according to modification of the present invention, (B) Side view of the cored bar

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the spring molding machine 10 according to the present embodiment includes a wire feed guide 13, first and second molding tools 14, 15, around a cored bar 20 protruding from the front surface of the support wall 11. And the cutting tool 16 is provided. The wire feeding guide 13 guides the wire 90 fed from a wire feeding device (not shown) in parallel and horizontally with the front surface of the support wall 11 so as to pass near the lower side of the core bar 20.

  The 1st shaping | molding tool 14 is faced | matched from the diagonally downward side on the opposite side to the wire rod feed guide 13 with respect to the metal core 20, and the 2nd shaping | molding tool 15 is opposite to the wire rod feed guide 13 with respect to the metal core 20. It is butted from the diagonally upper side. Further, guide grooves 14M and 15M are formed on the front end surfaces of the first and second forming tools 14 and 15, respectively. Then, the wire rod 90 fed from the wire rod feed guide 13 is formed into a coil spring 91 that slidably contacts the inner surfaces of the guide grooves 14M and 15M and surrounds the cored bar 20. The first and second forming tools 14 and 15 can move directly in the direction in which the first and second forming tools 14 and 15 are in contact with and separated from the core metal 20, thereby forming a coil spring 91 having an arbitrary coil diameter. it can.

  The cutting tool 16 has a prismatic structure extending in the vertical direction, and includes cutting edges 16E at corners of one side surface 16A and the lower end surface 16B facing the second molding tool 15 side. Further, as shown in FIG. 4, the lower end surface 16B of the cutting tool 16 is inclined so as to be directed upward as the distance from the cutting edge 16E increases. Then, when the coil spring 91 is formed to a predetermined coil length, the cutting tool 16 descends, and the wire 90 is moved between the cutting edge 24 described later of the core metal 20 and the cutting edge 16E of the cutting tool 16. The coil spring 91 is cut off from the subsequent wire rod 90 by being sandwiched and cut.

  FIG. 2 shows the entire cored bar 20. The cored bar 20 is formed by cutting a part of a corner of a tip of a round member 70 such as carbon steel having a predetermined length with a rotary cutting tool 80 (for example, a milling cutter). Specifically, the round member 70 is fixed to a milling machine jig (not shown) in such a manner that the axial direction of the round member 70 and the axial direction of the rotary cutting tool 80 are orthogonal to each other. In this state, a part of the tip corner portion of the round member 70 is repeated by repeating the operation of laterally moving the rotary cutting tool 80 in a direction inclined with respect to the center line 20C of the round member 70 (moving in a direction perpendicular to the rotation axis direction). We will excise. Finally, the end surface 80A of the rotary cutting tool 80 is disposed so as to be in contact with the virtual plane 20M including the center line 20C of the round member 70, and the rotary cutting tool 80 is laterally moved, so that the round member 70 has a virtual plane. A notch 21 having a central cut surface 22 overlapping with 20M is formed. In this way, the metal core 20 is manufactured from the round material 70. If necessary, the round member 70 may be cut to form the cored bar 20, and then a finishing process such as heat treatment or grinding may be performed.

  The notch portion 21 of the core metal 20 has a shape that excludes one side portion of the center cut surface 22 from the round member 70 and has a depth that does not reach the center line 20C of the core metal 20. In addition, the intersection between the center cutting surface 22 and the outer peripheral surface 20G of the cored bar 20 is a cutting edge 24 according to the present invention, and the core cutting surface 22 has a core opposite to the cutting edge 24 on the opposite side. An inclined edge portion 22A that gradually approaches the cutting edge 24 as the distance from the tip of the gold 20 is provided. The side cut surface 23 formed by the side surface 80 </ b> B of the rotary cutting tool 80 is orthogonal to the inclined edge portion 22 </ b> A of the cutting edge 24.

  As shown in FIG. 3, a support hole 12 is formed through the support wall 11 to support the cored bar 20. And the base end side is inserted into the support hole 12 from the intermediate position in the axial direction of the metal core 20 to form the round bar trunk 20L according to the present invention, and the front end side of the metal core 20 from the intermediate position is the front of the support wall 11. The cantilever portion 20K according to the present invention protrudes into a cantilever shape.

  In order to fix the cored bar 20 to the support wall 11, a fixing element 30 is attached to the rear end portion of the support hole 12. The fixing element 30 has a structure in which a fastening sleeve 30B (corresponding to the “clamping ring” of the present invention) is extended from a rear end inner edge of the base ring 30A (corresponding to the “ring fixing part” of the present invention). It has become. The rear end portion of the support hole 12 is fixed to the support wall 11 with a bolt in which a base ring 30A is fitted to a rear end recess 31 formed by expanding the diameter in a stepped manner, and the fastening sleeve 30B is fixed to the support wall 11. Protrudes behind. Further, the tightening sleeve 30B has a shape whose outer diameter is narrowed away from the base ring 30A, and a tapered screw 30N is formed on the tapered outer peripheral surface thereof. Further, the inner peripheral surfaces of the tightening sleeve 30B and the base ring 30A are flush with the inner peripheral surface of the support hole 12, and the round bar trunk portion 20L of the cored bar 20 is fitted therein. In addition, a plurality of longitudinal slits (not shown) are formed from a rear end to a position closer to the front end at a plurality of positions in the circumferential direction of the fastening sleeve 30B. Then, a nut 32 (corresponding to an “outer taper member” of the present invention) provided with a taper screw 32N on the inner peripheral surface is fastened to the taper screw 30N of the fastening sleeve 30B, and the diameter of the fastening sleeve 30B is reduced. . As a result, the cored bar 20 is fixed to the support wall 11 via the fixing element 30.

  As shown in FIG. 1, the notch 21 of the cored bar 20 fixed to the support wall 11 is positioned below the cutting tool 16, and the center cutting surface 22 of the notch 21 as shown in FIG. 16 is arranged flush with one side surface 16A on the cutting edge 16E side. As a result, the cutting tool 16 is lowered as described above, and the wire 90 sandwiched between the cutting edge 24 of the core bar 20 and the cutting edge 16E of the cutting tool 16 is cut, and the coil spring 91 is moved. It is cut off from the subsequent wire 90.

  In the present embodiment, the outer peripheral surface of the fastening sleeve 30B on which the tapered screw 30N is formed corresponds to an “outer peripheral tapered surface”, and the inner peripheral surface of the nut 32 on which the tapered screw 32N is formed is the main surface. This corresponds to the “inner peripheral tapered surface” according to the invention. Further, the tightening sleeve 30B and the taper screws 30N and 32N of the nut 32 correspond to the “propulsion mechanism” according to the present invention. Furthermore, the “core metal fixing means” according to the present invention is constituted by the fixing element 30 and the nut 32.

  This completes the description of the configuration of the spring forming machine 10 of the present embodiment. Next, the function and effect of the spring forming machine 10 will be described. The metal core 20 of the spring forming machine 10 of the present embodiment can be easily manufactured by causing the round member 70 to cross the rotary cutting tool 80 (see FIG. 2). Here, when the metal core 20 is arranged inside the coil spring 91 with the circular material 70 as a base material, the core metal 20 comes into contact with the inner peripheral surface of the coil spring 91 only at one place in the circumferential direction (see FIG. 4). Therefore, if the cutting edge 24 is formed at a portion that becomes a contact point between the round member 70 and the coil spring 91, the core bar 20 can be easily and in a short time compared to the case where the core bar is manufactured from the square bar as in the prior art. As shown in FIG. 2, the cored bar 20 thus manufactured has a structure having a cutting edge 24 in a virtual plane 20M including the center line 20C of the round bar trunk 20L. become. In other words, the cored bar 20 of the present embodiment having a structure including the cutting edge 24 in the virtual plane 20M including the center line 20C of the round bar trunk 20L can be manufactured more easily and in a shorter time than conventional. Production costs can be reduced. Further, since the support hole 12 formed in the support wall 11 also has a circular cross section corresponding to the cored bar 20, it can be formed easily and in a shorter time than a conventional support hole having a square cross section.

[Second Embodiment]
A core bar 20V provided in the spring forming machine of the present embodiment is shown in FIG. 5, and only the shape of the notch 21V is different from that of the first embodiment. That is, in the core bar 20V, a semi-cylindrical body having a semicircular cross section is cut from the tip of the round bar, and a notch 21V is formed. The center cut surface 22V of the notch 21V is 2 on the outer peripheral surface of the core 20V. A pair of cutting edges 24, 24 are provided so as to intersect each other. In addition, the side cut surface 23V of the notch 21V forms a semicircle and is orthogonal to the center cut surface 22V. Even with such a structure, the manufacturing cost of the cored bar 20V can be reduced as in the first embodiment.

[Third Embodiment]
The core bar 20W provided in the spring forming machine of the present embodiment is shown in FIG. 6, and the cantilever portion 20K includes a tapered portion 20T having a diameter gradually reduced from the round rod trunk portion 20L, and the tapered portion 20T. The structure is provided with a main body 20H having a notch 21V at the tip. The main body 20H has the same shape as the tip of the core bar 20V of the second embodiment, and the outer diameter is smaller than the tip of the core bar 20V of the second embodiment.

  The core bar 20W of this embodiment can be used for a coil spring having a small diameter. In addition, when the cored bar 20W of the present embodiment for a coil spring having a small diameter and the cored bar 20V of the second embodiment for a coil spring having a large diameter are used in exchange for the support holes 12, they are used. The fixing structure of the core bars 20V and 20W on the support wall 11 can be made the same by making the round bar trunk portions 20L of the core bars 20V and 20W have the same shape.

[Fourth Embodiment]
A core bar 20X provided in the spring forming machine of the present embodiment is shown in FIG. 7A, and includes a pair of notches 21 and 21 arranged in plane symmetry. According to this configuration, the direction of the surface to be cut in the coil spring 91 can be changed in the reverse direction by rotating the cored bar 20X and changing it from one notch 21 to the other notch 21. it can.

[Fifth Embodiment]
The core bar 20Y provided in the spring forming machine of the present embodiment is shown in FIG. 7B, and is provided at two positions where the pair of notches 21 and 21 are rotated 180 degrees around the center line 20C. Yes. According to this configuration, when the cutting edge 24 of one notch 21 is worn or damaged, the cored bar 20Y can be rotated to change to the cutting edge 24 of another notch 21.

[Sixth Embodiment]
The spring forming machine 10V of this embodiment is shown in FIG. 8, and the fixing structure of the cored bar 20 is different from the spring forming machine 10 of the first embodiment. That is, in the spring forming machine 10V of the present embodiment, the outer ring 54 (corresponding to the “ring fixing portion” of the present invention) and the inner ring 55 (the main ring 55) are formed in the rear end recess 31 formed in the rear end portion of the support hole 12. Corresponding to the “clamping ring” of the invention. The outer ring 54 is in a state where one end surface abuts on the step surface 31 </ b> D between the rear end recess 31 and the support hole 12 and the outer peripheral surface abuts on the inner peripheral surface of the rear end recess 31. The outer ring 54 has an inner tapered surface 54A according to the present invention on the inner side, and the inner tapered surface 54A is gradually reduced in diameter toward the step surface 31D.

  On the other hand, the inner ring 55 has an outer tapered surface 55A according to the present invention on the outer side, and the outer ring 54 and the core metal 20 in a state where the outer tapered surface 55A is in surface contact with the inner tapered surface 54A of the outer ring 54. It is fitted in the gap between.

  An air cylinder 50 (corresponding to the “propulsion mechanism” of the present invention) is attached to the rear surface of the support wall 11 via a bracket 51 so as to close the support hole 12. A linear motion rod 52 provided in the air cylinder 50 passes through the bracket 51, and a pressure sleeve 53 (corresponding to the “propulsion mechanism” of the present invention) attached to the front end of the linear motion rod 52 is a rear end. It enters the gap between the recess 31 and the cored bar 20 and abuts against the inner ring 55.

  Then, when a predetermined operation button (not shown) is turned on, the pressure sleeve 53 is held in a state of pressing the inner ring 55. As a result, the outer ring 54 is enlarged in diameter, while the inner ring 55 is reduced in diameter, the outer ring 54 is frictionally fixed to the inner peripheral surface of the rear end recessed portion 31, and the inner ring 55 is fixed to the outer peripheral surface of the cored bar 20. The outer ring 54 and the inner ring 55 are frictionally fixed, and the core metal 20 is fixed to the support wall 11 so that it cannot rotate and cannot move directly. Further, when a predetermined operation button (not shown) is turned off, the pressure sleeve 53 is retracted, the outer ring 54 and the inner ring 55 are elastically restored, and the core metal 20 is rotated and linearly moved with respect to the support wall 11. Is possible. Thereby, the position change and replacement | exchange of the metal core 20 can be performed easily.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

  (1) The core bar 20Y of the fifth embodiment has two pairs of notches 21 and 21 rotated by 180 degrees around the center line 20C, but the three notches 21 are provided with the core 20Y. For example, as shown in FIGS. 9 (A) and 9 (B), four notches 21 may be provided on the core 20Z. You may prepare for the state rotationally moved to four places of the circumferential direction.

  (2) The cored bar 20 of each embodiment described above has a structure in which the cutting edge 24 is included in the virtual plane 20M including the center line 20C of the round bar trunk 20L. A structure in which the cutting edge 24 is included in the shifted near virtual plane may be used. For example, in FIG. 4, a structure in which the cutting edge 24 and the central cutting surface 22 are provided so as to be shifted from the virtual plane 20 </ b> M to the left and right vicinity may be used.

  (3) Although the cantilever part 20K of the cored bar 20 of each embodiment described above has a shape obtained by cutting out a part of a round bar, the cantilever part has a prismatic shape with a polygonal section with a sharp upper side. It may be.

  (4) As a structure for fixing the metal core to the support wall, for example, a structure in which a sleeve is protruded from the opening edge on the rear surface side of the support hole, and the sleeve and the metal core are combined to have a pin penetrating from the side. There may be. In addition, the core metal is locked to the support wall with a key, and the bolt is passed through a plate that closes the opening on the rear surface of the support hole and tightened to the core metal to fix the core metal so that it cannot be moved directly. May be.

10, 10V Spring forming machine 11 Support wall 12 Support hole 16 Cutting tool 16E Cutting edge 20, 20V-20Z Core metal 20C Center line 20G Outer peripheral surface 20K Cantilever part 20L Round bar trunk part 20M Virtual plane 20T Taper part 21, 21V Notch 22, 22V Center cut surface 22A Inclined edge 24 Cutting edge 30 Fixing element (core metal fixing means)
30A Base ring (ring fixing part)
30B Clamping sleeve (clamping ring, propulsion mechanism)
30N, 32N taper screw (propulsion mechanism)
32 Nut (core fixing means, outer taper member, propulsion mechanism)
50 Air cylinder (propulsion mechanism)
53 Pressure sleeve (propulsion mechanism)
54 Outer ring (ring fixing part)
54A Inner taper surface 55 Inner ring (clamping ring)
55A Outer taper surface 70 Round material 90 Wire material 91 Coil spring

Claims (9)

A coil spring is formed from a wire rod so as to surround the core metal protruding in a cantilever shape from the support wall, and the cutting edge of the cutting tool that approaches the core metal from the side and the cutting edge of the core metal A spring molding machine that sandwiches the wire and separates the coil spring from the subsequent wire.
A support hole having a circular cross section formed in the support wall;
A round bar stem having a circular cross section provided in the core bar and fitted into the support hole;
A cantilever portion of a size that is provided on the metal core, protrudes in a cantilever shape from the support wall, and fits within a cylindrical surface extending the outer peripheral surface of the round bar stem;
A cored bar fixing means for fixing the round bar trunk to the support hole,
The spring forming machine in which the cutting edge is included in a virtual plane including a center line of the round bar trunk portion in the cantilever portion or in a near virtual plane shifted to the vicinity from the virtual plane. The cantilever part is formed by forming a notch in a round bar body concentric with the round bar trunk part,
The notch has a central cut surface that overlaps the virtual plane or the neighboring virtual plane including the cutting edge, and has a shape that excludes one side portion of the central cut surface from the round bar. The spring forming machine according to claim 1, wherein the cutting edge is provided at an intersection between the center cutting surface and the outer peripheral surface of the round bar.   The center cut surface intersects at one place in the circumferential direction of the outer peripheral surface of the round bar body, and the opposite side of the cutting edge of the center cut surface is located inside the outer peripheral surface of the round bar body. The spring forming machine according to claim 2.   4. The spring according to claim 3, wherein an inclined edge portion that gradually approaches the cutting edge as the distance from the tip of the cantilever portion is provided on the opposite side of the cutting edge of the central cutting surface. Molding machine.   5. The spring forming machine according to claim 3, wherein the notch portions are arranged in pairs and symmetrical with respect to the cantilever portion.   5. The spring forming machine according to claim 3, wherein a plurality of the cutout portions are formed in a state of being rotationally moved to a plurality of positions around a center line of the cantilever portion.   The said cantilever part consists of the taper part gradually diameter-reduced toward the front from the said round bar trunk part, and the main-body part extended in the front from the front-end | tip of the said taper part, and having the said notch part. The spring forming machine according to claim 1. As the core metal fixing means,
A tightening ring that is fitted to the round bar stem and is reduced in diameter and frictionally fixed to the core;
A ring fixing portion for fixing the clamping ring to the support wall so as not to rotate and to move directly;
An outer peripheral tapered surface formed on the outer peripheral surface of the clamping ring;
An outer tapered member that is fitted to the outside of the clamping ring and has an inner circumferential tapered surface that abuts the outer circumferential tapered surface;
The spring forming machine according to any one of claims 1 to 7, further comprising a propulsion mechanism for moving and holding the outer taper member in a direction of deepening the fitting with the tightening ring.   The spring forming machine according to any one of claims 1 to 8, wherein a key for key-connecting the support hole and the core metal is provided as the core metal fixing means.

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