Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21F—WORKING OR PROCESSING OF METAL WIRE
  • B21F35/00—Making springs from wire
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21F—WORKING OR PROCESSING OF METAL WIRE
  • B21F35/00—Making springs from wire
  • B21F35/02—Bending or deforming ends of coil springs to special shape
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21F—WORKING OR PROCESSING OF METAL WIRE
  • B21F3/00—Coiling wire into particular forms
  • B21F3/02—Coiling wire into particular forms helically
  • B21F3/027—Coiling wire into particular forms helically with extended ends formed in a special shape, e.g. for clothes-pegs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21F—WORKING OR PROCESSING OF METAL WIRE
  • B21F3/00—Coiling wire into particular forms
  • B21F3/10—Coiling wire into particular forms to spirals other than flat, e.g. conical

Definitions

• the present invention relates to a method and an apparatus of making a spring. More particularly, it relates to a method and an apparatus of making a spiral spring.
• a spring of a spring scale or a sofa a valve spring of a safety valve and a plate spring supporting a wheel of a car use an elasticity of a metal.
• Properly heat-treated steel is mainly used as a material of a spring.
• Metal such as phosphor bronze or nickel alloy is also used as a material of a spring.
• rubber or air is used as a material of a spring.
• Springs of metal are classified into a coil (helical) spring, a ring spring, a plate spring and a spiral spring according to a shape of a spring.
• the coil spring is formed through helically winding a rod-shaped metallic material whose cross-section is circle or polygon.
• the coil spring is used for extension or contraction and the coil spring for contraction may be made twofold or threefold.
• the plate spring may be used by stacking several plates.
• the plate spring of trapezoidal or triangular shape is used for a place where big external force is applied, for example, a car or a train.
• the spiral spring is formed through winding a band-shaped steel and used for a clock.
• a spring has mechanical characteristics such as an elastic limit, a fatigue limit and a hardness.
• the present invention particularly relates to a method and an apparatus of making a spiral spring shown in FIG. 1 A.
• a transferred spring-material having a shape of line or plate is inserted into a hole disposed at one end of a spindle.
• a bending portion 2 of the spiral spring is formed through bending the spring-material inserted into the hole due to a first rotation of the spindle.
• the spring-material is wound along a circumference of the spindle according to rotations of the spindle. This process is referred to as a coiling or a winding.
• the spring-material is made move to the spindle by force.
• the hole portion of the spindle winding the spring-material is referred to as a caliber guide.
• a slide having a shape of hook presses and cuts the spring-material transferred from a rear of the spindle to form a hook 4.
• the spindle should rotate reversely. If the spindle does not rotate reversely, it is hard to divide the wound spring from the spindle. This process is referred to as a back coiling.
• a pitch is determined through winding the spring-material densely, partially unwinding by the back coiling and separating from the spindle by free fall. Since the pitch is determined by the elasticity, the pitch and a space may not be uniformly adjusted. Therefore, there is a problem that a desired load is not uniformly obtained. Since the most important thing of a spring is a guarantee of uniform load, a spring of non-uniform load is regarded as that of bad quality. There is another problem that a bulging portion is generated. In the method of fabricating a conventional spiral spring, even though the spring is unwound by the back coiling of the spindle, a bilging portion 8 shown in FIG.
• the bulging portion also has a bad influence on the guarantee of the uniform load. Moreover, when the spring having the bulging portion is equipped to a compact product, the product may have a bad quality due to hard equipment.
• the present invention is directed to an apparatus of making a spiral spring that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
• An object of the present invention is to provide a method and an apparatus of fabricating a spiral spring that has a uniform pitch arid a guarantee of a uniform load without generating a bulging portion.
• FIG. 1A is a plan view of a spiral spring
• FIG. IB is a cross-sectional view showing a bulging portion of a conventional spiral spring
• FIG. 2 is a schematic plan view of a fabricating apparatus of a spiral spring according to the present invention
• FIGs. 3 to 6 are schematic plan views of the apparatus of FIG. 2 according to a fabricating step
• FIG. 7 is a schematic cross-sectional view of the apparatus of FIG. 2;
• FIG. 8 is a schematic plan view of another embodiment of the present invention.
• FIG. 9 is a schematic flowchart showing a fabricating method using an apparatus according to the present invention.
• Feed roller 20 Spring-material
• the present invention provides a method of making a spiral spring including: transferring a spring-material; full bending one end of the transferred spring-material to correspond to a finished product; coiling the spring-material whose one end is bent by a forced contact to have a uniform pitch; forming a hook at the coiled spring-material and simultaneously cutting the coiled spring-material; and continuously half bending one end of a newly transferred spring-material.
• the "full bending” means a necessary bending to a finished product. Generally, it means that an angle between a spring-material and a bent portion is smaller than about 90°.
• the "half bending” means a bending with an angle larger than the angle of the "full bending”.
• a transfer of the spring-material is performed by a feed roller and a transfer speed may be variable.
• the present invention also provides an apparatus of making a spiral spring including: a feed roller transferring a spring-material; a first slider bending one end of the transferred spring-material, the first slider sliding along a transferring direction of the spring-material; a second slider having a contact portion contacting the spring-material whose one end is bent, a sliding distance of the second slider becoming shorter according to lapse of time, thereby a distance between the contact portion and a center of an wound spring-material becoming longer to form a pitch; and one pair of third and fourth sliders respectively having a corresponding hook-forming portion and a corresponding cutting portion, the one pair of third
• the contact portion of the second slider may have a shape of roller.
• the feed roller continuously transfers the spring-material. Sliding back and forth, and a sliding distance may be adjusted by a rotation of a cam at an outer end of each slider.
• the cam driving each slider may be rotated by a small gear linked to a large gear.
• each slider may be driven an individual cylinder or a servomotor.
• the cylinder is a hydraulic cylinder.
• FIG. 2 is a schematic plan view of a fabricating apparatus of a spiral spring according to the present invention.
• a fabricating apparatus is divided into a roller feed 10 transferring a spring-material 20 having a shape of line or plate by force, and a spring-fabricating portion 100 where a spring is fabricated by using the spring-material transferred from the roller feed.
• the shape of the roller feed 10 is an example and many shapes may be applied to the roller feed.
• the shape is not a point of the present invention and a means continuously transferring the spring-material is sufficient for the roller feed.
• the roller feed may transfer the spring-material 20 with a variable speed or a constant speed as shown in the embodiment. If the speed varies, the other elements of the spring-fabricating portion 100 may vary according to the speed.
• the spring- fabricating portion 100 includes: an output portion 110 where the spring- material 20 is ejected; a bending portion 120 bending one end of the spring-material 20 ejected and transferred form the output portion 110; a coiling portion 130 contacting and winding the spring-material 20 whose one end is bent by the bending portion 120 with a variable distance; and one pair of hook-forming portions 141 and 142 forming a hook at the other end of the spring-material 20 wound by the coiling portion 130, and cutting.
• the bending portion 120, the coiling portion 130 and one pair of hook-forming portions 141 and 142 slide, respectively. Thus, they may be referred to as sliders.
• a length of each slider is adjusted by a cam 105 and a return spring 107 is installed for the forced contact of each slider and the cam.
• the return spring 107 is an example and another shape may be adopted. Means that forcedly returns the slider pushed by the cam is sufficient and the means can be disposed at different positions.
• the output portion 110 does not slide but is fixed.
• One end of the output portion has a shape of a straight line 121 to secure a space for sliding of one end of the bending portion 120. Since this shape is an example to secure a space of the bending portion 120, another shape can be adopted.
• FIG. 3 is a schematic plan view showing a bending process.
• One end 20a of a spring-material 20 transferred through the output portion 110 which is half bent in a previous fabricating process, is full bent when a bending portion 120 slides from an opposite direction to the output portion 110 due to a rotation of the cam 105, and grazes the output portion 110.
• a coiling process (a winding process) is performed as a coiling portion 130 slides and contacts a spring-material 20 due to a rotation of a cam 105 of the coiling portion 130.
• an outer coil having a uniform pitch from an imier coil is formed when the coiling portion 130 is pushed back according to a shape of the cam 105.
• the pitch may be adjusted by changing the shape of the cam 105. Even though a contact portion of the coiling portion 130 with the spring-material 20 may be simple, i.e., not be a shape of roller 132, the shape of roller 132 is preferable to reduce a frictional force during the coiling process.
• a sliding direction of the coiling portion 130 is at a specific angle with a transfening direction of the spring-material 20.
• FIG. 5 is a schematic plan view showing a forming process of a shape of hook.
• One pair of hook-forming portions 141 and 142 as also shown in FIG. 2, have hook-shape portions 143 a and 143b, and a cutting portion.
• the hook-shape portions 143 a and 143b have uneven shapes to fonn a hook 4 (of FIG. 1A).
• the cutting portion has a groove 145 of a shape of slit at one hook-forming portion 142 and a protrusion 147 fitted to the groove 145 at the other hook-forming portion 141.
• the one pair of hook-forming portions 141 and 142 are at about right angles to the transferring direction.
• shapes of cams driving first and second hook-forming portions 141 and 142 are different from each other.
• the first hook-forming portion 141 moves to the right side of FIG. 6 and half bends a newly transferred spring-material 20 by pushing one end thereof while the second hook-forming portion 142 returns to the right side of FIG. 6.
• the cam driving the first hook-forming portion 141 has first and second big diameters "dl” and "d2" (of FIG. 2) and the second big diameter "d2" is longer than the first big diameter "dl”.
• FIG. 7 is a schematic cross-sectional view of the apparatus of FIG. 2, showing a driving principle of the cam 105.
• the cam 105 is rotated by a small gear 112. Further, each small gear 112 may be combined with and linked to a large gear 114. Or each small gear 112 may be driven individually.
• a direction of each cam 105 is shown roughly and is an example because each cam may be driven independently.
• the large gear 114 is driven by a motor "M" through a gear train 116 of diverse shapes or structures.
• the shape or structure of the gear train 116 may be adequately selected considering the motor "M”, the large gear 114 and a number of rotations.
• FIG. 8 is a schematic plan view of another embodiment of the present invention. Even though FIG. 8 is similar to FIG. 2, FIG. 8 shows that each slider 120, 130, 141 or 142 may be driven not by a cam but by an individual cylinder 106 operated by a control unit (not shown).
• the cylinder 106 is a hydraulic cylinder and each slider of the present invention may be driven by a servomotor.
• FIG. 9 is a schematic flowchart showing a fabricating method using an apparatus according to the present invention.
• the fabricating method includes: a full bending step "SI" of one end 20a of a spring- material 20 half bent in a previous step by a bending portion 120 (a first slider); a coiling step “S2" of the spring-material 20 by a contact with a coiling portion 130 (a second slider); a forming and cutting step "S3" of a hook at the coiled spring-material 20 by one pair of hook- forming portions 141 and 142 (third and fourth sliders); and a half bending step "S4" of one end of a newly transferred spring-material through an output portion 110 by the third slider.
• finished products are collected by free fall.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Wire Processing (AREA)
• Springs (AREA)

Applications Claiming Priority (2)

Publications (1)

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Cited By (1)

Families Citing this family (10)

Citations (4)

• 2001
  • 2001-04-16 KR KR10-2001-0020245A patent/KR100374799B1/ko not_active Expired - Fee Related
  • 2001-06-04 WO PCT/KR2001/000950 patent/WO2002083336A1/en active Application Filing

Patent Citations (4)

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