CN111936250A

CN111936250A - Apparatus and method for forming a spring

Info

Publication number: CN111936250A
Application number: CN201880085407.5A
Authority: CN
Inventors: 西蒙·斯平克斯; 大卫·克莱尔
Original assignee: Harrison Spinks Components Ltd
Current assignee: HS Products Ltd; Harrison Spinks Components Ltd
Priority date: 2017-11-09
Filing date: 2018-11-02
Publication date: 2020-11-13
Also published as: GB201718529D0; GB2578720B; EP3706932A1; CA3082059A1; AU2018363284A1; WO2019092404A1; US20210187588A1; GB201817923D0; GB2578720A

Abstract

A spring forming apparatus is generally indicated at (200) in which a metal wire (220) is fed by a feed roller (230) from a supply (not shown) to a forming station (250) via an irregularity-generating roller (240). The forming station includes a first deflector (260) and a second deflector (270). When the spring S is completed, the spring S automatically separates from the rest of the wire (220) due to the presence of the irregularities (280), without the need for a cutting device.

Description

Apparatus and method for forming a spring

Technical Field

The invention relates to an apparatus for forming a spring and a method of forming a spring. And particularly, but not exclusively, to an apparatus and method for forming a coil spring constructed from wire.

Background

The manufacture of helical coil wire springs currently involves a number of steps. First, the wire is removed from a supply, typically a spool, using feed rollers and, if necessary, straightened to eliminate any kinks or twists. The wire is then formed into a helical coil using a first deflection tool to induce bending in a first direction, followed by inducing bending in a second direction using a second deflection tool arranged substantially perpendicular to the first deflection tool. This pushes the wire out of the plane and into a helix. The pitch tool controls the spacing of adjacent turns of the coil as desired, and the cutter severs the spring from the remainder of the wire when the coil has a predetermined length.

Fig. 1 schematically illustrates an example of a previously considered spring forming apparatus, generally designated 100. The spool 110 typically dispenses the wire 120 under the control of servo-driven pairs of feed rollers 130. The wire passes through guide rollers 140 to a forming station 150. The forming station includes a first deflector 160, the first deflector 160 deflecting the straight wire in a first direction having a vector component of about 90 degrees relative to the original axis of the wire. The wire then encounters the second deflector 170, and the second deflector 170 deflects the wire in a second direction having a vector component of about 90 degrees relative to both the original axis of the wire and the first direction. The result is a helical coil spring S.

There are several other previously considered methods of forming springs from wire. Almost all of these methods involve bending the wire, usually by pushing the wire against some kind of deflection tool.

The pitch tool (omitted from the drawings for clarity) determines the spacing between adjacent coils of the spring. When the spring reaches a predetermined length, the cutter 180 severs the spring from the remainder of the wire.

In order to perform a clean, accurate cut, the feeding of the wire must be temporarily stopped or at least significantly slowed down when the cutter is introduced. Immediately after cutting, the feed must be resumed. In the example shown, the cutter 180 includes a tool 190, the tool 190 being mounted for elliptical/rotational engagement with the wire, so that there is no need to completely stop movement of the wire for a clean cut.

Most of the wire is supplied from a reel, weighing hundreds of kilograms when the reel is full. Therefore, the reel and the feed roller must be servo-controlled to maintain the correct tension in the feed. When the wire undergoes an acceleration cycle, the motor driving the feed rollers must be powerful enough to operate the wire supply with considerable inertia. As higher production speeds are required, some current cushion unit manufacturers require springs to be produced at 300 springs per minute, the problem becomes more severe and more complex and thus expensive drive equipment is required.

Another example of the prior art is disclosed in WO 2015/007496. In this document, a weakening is introduced into the length of the spring wire on two diametrically opposed portions of the wire surface before the cutting device cuts the formed spring from the rest of the wire. However, this method does not solve the problem of temporarily stopping the feed for the purpose of deploying the cutting tool, and all the attendant drawbacks mentioned above.

Disclosure of Invention

Embodiments of the present invention aim to at least partially solve the aforementioned problems.

The invention is defined in the appended independent claims, to which reference should now be made. Further, preferred features may be found in the appended dependent claims.

According to one aspect of the present invention there is provided a method of manufacturing a spring from a spring medium, the method comprising creating an irregularity in a portion of the spring medium and then deflecting the spring medium to form it into a spring, whereby the deflection is arranged to cause a discontinuity in the spring medium at the location of the irregularity.

Preferably, the method comprises feeding spring medium from a supply source to the spring forming apparatus.

The method may include creating an irregularity in the spring media, the creating the irregularity including forming at least one localized cut, indentation, notch, depression, deformation, or weakening in the spring media.

The method preferably includes creating irregularities in the spring medium using one or more rollers.

In a preferred arrangement, the irregularities are formed without stopping the movement of the spring media, and more preferably, without slowing the movement of the spring media.

According to another aspect of the invention, there is provided an apparatus for manufacturing springs from spring media, the apparatus comprising feeding means for feeding the spring media and spring forming means for forming the springs by deflecting the spring media, wherein the deflection applied by the spring forming means is arranged for creating a discontinuity in the spring media at the location of a previously formed irregularity.

Preferably, the apparatus further comprises irregularity forming means for forming irregularities in the spring medium.

In a preferred arrangement, the irregularity forming means is arranged to form an irregularity in the spring medium, the irregularity comprising at least one local cut, indentation, depression, deformation or weakening in the spring medium.

The irregularity forming means may include one or more rollers.

The spring medium preferably comprises a mass of substantially unbent material to form a spring by deflecting the material to bend it.

The spring medium may comprise a wire, and more preferably comprises a metal wire.

In a preferred arrangement, due to the irregularity, the spring medium is arranged to break by the deflecting action of the spring forming means, thereby separating the formed spring from the rest of the spring medium.

The invention also includes a program for causing an apparatus to perform a method of manufacturing a spring according to any statement herein.

According to another aspect of the present invention there is provided an apparatus comprising a processor and a memory having computer readable instructions therein, the processor being arranged to read the instructions to cause performance of a method according to any statement herein.

In another aspect, the invention provides a computer program product on a non-transitory computer readable storage medium, comprising computer readable instructions which, when executed by a computer, cause the computer to perform a method of manufacturing a spring according to any statement herein.

The invention also includes a spring formed by a method or apparatus according to any statement herein.

The invention may comprise any combination of features or limitations mentioned herein, except combinations of features that are mutually exclusive or mutually contradictory.

Drawings

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

figure 1 schematically illustrates a previously considered apparatus for forming a spring;

FIG. 2 schematically illustrates an apparatus for forming a spring according to an embodiment of the invention;

FIG. 3 illustrates a portion of a spring medium containing irregularities;

fig. 4 shows a pair of rollers used to form the irregularity of fig. 3.

Detailed Description

Turning to fig. 2, fig. 2 schematically illustrates a spring forming apparatus, indicated generally at 200, in accordance with an embodiment of the present invention. The wire 220 is fed from a supply source (not shown) to a forming station 250 via irregularity-generating rollers 240 by feed rollers 230. The forming station includes a first deflector 260 and a second deflector 270, the first deflector 260 and the second deflector 270 operating in substantially the same manner as the previously considered deflectors of the spring forming station described above with reference to fig. 1. However, in this embodiment there is no cutter. As will be described below, when the spring S is completed, the spring S automatically separates from the rest of the wire 220 due to the presence of the irregularity 280.

The pair of irregularity generating rollers 240 includes an upper roller 242 and a lower roller 244. Each roller has a channel 246 in which the wire 220 is guided. In most cases, roller 240 is stationary and wire 220 slides through channel 246. When an irregularity is to be introduced, the rollers rotate and the anvil 248 located in the channel of the upper roller becomes pressed against the wire, resulting in the introduction of an irregularity 280 in the wire.

The timing and movement of the rollers 240 is computer controlled so that the irregular positions can be accurately specified.

Fig. 3 is a more detailed view of the wire 220 including irregularities 280 formed by the rollers 240.

Fig. 4 shows

rollers

242 and 244. On the left side is the lower roller of fig. 2, showing the wire 220 in the channel 246. On the right side is the upper roller of fig. 2, showing the irregularly shaped anvil 248. When irregularities are to be formed, the

rollers

242 and 244 rotate and the anvil 248 presses the wire against the channel 246 of the lower roller. This allows the feature 280 to be in a precisely determined position as shown in fig. 3.

As the wire advances toward the spring forming station 250, the feature 280 will eventually encounter the first deflector 260. When this occurs, the wire will break cleanly, and the spring S formed before the feature 280 will separate from the rest of the wire 220. This is because the presence of the irregularities 280 concentrates the stress in the wire when it is subjected to bending forces.

There is no need for a cutter and therefore no need to slow down the feed, let alone stop the feed. This allows the spring to be manufactured at a greater rate.

Thus, the heavy and expensive feed rollers currently used in the apparatus shown in fig. 1 are no longer required.

Other arrangements for forming irregularities may be used. For example, in another embodiment (not shown), the wire may be pressed between two opposing irregularly-formed anvils, or for example between one anvil on one roller and a pair of complementary supports on the other roller. Further, while the example of the irregularity 280 above is a V-shape, it is understood that the irregular shape and/or depth may be different.

By varying the pressure applied by the rollers 240 and/or the distance of the one or more anvil features 248 from the wire, adjustments may be made for wires of different diameters.

The timing of the irregularity forming operation can be accurately controlled by controlling the operation of the roller 240 or the operation of only the single roller 242 in the illustrated example.

One or more rollers need not be used to form the irregularities. Other mechanical means may be employed to create the weakening in the wire. In practice, the means for forming the irregularities need not be mechanical. For example, an energy source such as an arc or laser may also be used to introduce a weakening in the wire at a predetermined location.

Further, while the above example has irregularities formed after (i.e., downstream of) the feed roller, in another embodiment (not shown), the irregularities may be formed before (i.e., upstream of) the feed roller.

In some cases, the irregularities may be preformed on the wire, for example on another device, prior to introducing the wire into the spring forming apparatus.

The present invention is particularly effective in increasing the speed of spring manufacture when combined with an alternative supply source; the alternative supply comprises, for example, wire looped around the inside of a drum, the wire being substantially straight from the supply without tension. .

Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the applicant claims protection in respect of any patentable feature or combination of features whether or not particular emphasis has been placed thereon and/or shown in the drawings.

Claims

1. A method of manufacturing a spring from a spring medium, the method comprising creating an irregularity in a portion of the spring medium and then deflecting the spring medium to cause it to form a spring, whereby the deflection is arranged to cause a separation in the spring medium at the location of the irregularity.

2. The method of claim 1, wherein the method includes feeding the spring media from a supply to a spring forming apparatus.

3. The method of claim 1 or 2, wherein the method comprises creating irregularities in the spring medium, the irregularities comprising at least one localized cut, indentation, notch, depression, deformation, or weakening in the spring medium.

4. The method according to any one of the preceding claims, wherein the method comprises using one or more rollers to create the irregularities in the spring medium.

5. The method of any of the preceding claims, wherein the irregularity is formed without stopping movement of the spring media.

6. The method of any of the preceding claims, wherein the irregularity is formed without slowing movement of the spring medium.

7. An apparatus for manufacturing springs from spring medium, the apparatus comprising feeding means for feeding the spring medium and spring forming means for forming springs by deflecting the spring medium, wherein the deflection applied by the spring forming means is arranged for creating a separation in the spring medium at the location of previously formed irregularities.

8. The apparatus of claim 7, further comprising irregularity forming means for forming irregularities in the spring medium.

9. The apparatus of claim 8, wherein the irregularity forming device is arranged to form the irregularity in the spring medium comprising at least one localized cut, indentation, notch, depression, deformation, or weakening in the spring medium.

10. An apparatus according to claim 8 or 9, wherein the irregularity forming means comprises one or more rollers.

11. The apparatus of any of claims 7-10, wherein the spring medium comprises a mass of substantially unbent material to form a spring by deflecting the material to bend it.

12. The apparatus of any of claims 7-11, wherein the spring medium comprises a metal wire.

13. The apparatus of any one of claims 7 to 12, wherein due to the irregularity the spring medium is arranged to break by a deflecting action of the spring forming means, thereby separating the formed spring from the rest of the spring medium.

14. A program for causing an apparatus to execute the method of manufacturing a spring according to any one of claims 1 to 6.

15. An apparatus comprising a processor and a memory having computer readable instructions therein, the processor being arranged to read the instructions to cause performance of the method according to any one of claims 1 to 6.

16. A computer program product on a non-transitory computer readable storage medium, the computer program product comprising computer readable instructions which, when executed by a computer, cause the computer to perform a method of manufacturing a spring according to any one of claims 1 to 6.

17. A spring formed by the method of any one of claims 1 to 6 or by the apparatus of any one of claims 7 to 13 or 15.