DE102013206655B3 - Method and system for producing coil springs - Google Patents

Abstract

In a method and a system for manufacturing coil springs from wire, wire is conveyed from a wire supply to a numerically controlled spring manufacturing machine, sections of the wire are successively formed into coil springs in a forming operation in the spring manufacturing machine, each coil spring is separated from the supplied wire after the forming operation and severed coil springs are then transported to at least one downstream processing station. To transport helical springs, at least one spring transport magazine is used, which has a plurality of prepared receiving spaces for one helical spring each at defined positions of the spring transport magazine, with several separated helical springs provided in succession being distributed to different receiving spaces in a loading operation and as a spatially ordered group by means of of the spring transport magazine are transported in an orderly manner.

Description

BACKGROUND

The invention relates to a method for producing coil springs according to the preamble of claim 1 and to a system for producing coil springs according to the preamble of claim 11.

Coil springs are machine elements that are required in numerous applications in large numbers and different designs. Coil springs, also referred to as twisted torsion springs, are usually made of spring wire and are designed as tension springs or compression springs depending on the load involved in use. Compression springs, in particular suspension springs, are needed for example in large quantities in the automotive industry.

Coil springs are commonly manufactured today by first making a (raw) helical spring from a wire using a numerically controlled spring making machine in a forming process and then further processing it until the final finished product is obtained. For this purpose, one or more processing stations can be connected downstream of the spring production machine in the part flow.

In an automatic spring manufacturing machine, a wire (spring wire) coming from a wire supply is fed, under the control of an NC control program, by means of a feeder to a forming device of the spring manufacturing machine and formed into a coil spring by tools of the forming device.

Sometimes, the forming operation is to be followed by a heat treatment of the helical springs produced by forming, e.g. to improve the long-term elasticity by thermal aging. Since coil springs can be one of those products whose life can be significantly increased by shot peening, coil springs are occasionally reworked by shot peening. The spring end grinding is another frequently needed stage of further processing. In spring end grinding, the (axial) ends of the coil springs are machined by grinding to obtain flat spring end surfaces perpendicular to the spring axis. Finished coil springs can also be coated, painted, packaged or assembled immediately after forming or after one or more other operations.

Depending on the type of further processing or further processing, numerous different concepts for transporting coil springs have developed following the forming operation.

The WO 2007/028266 A1 describes by way of example a method for producing mattress spring cores, in which individual coil springs are produced by means of a spring coiling machine and individually picked up by a star conveyor rotating stepwise about an axis of rotation on the spring coiling machine and transported in succession over several stations arranged along the star conveyor until they are moved from taken over a pivoting conveyor and set for row formation on another conveyor.

In the apparatus and method for handling compression springs from the DE 38 09 494 A1 the compression springs are made in the manufacture by means of a device around an endless wire of small diameter and stored as a parts chain in a container. During further processing, the parts chain is fed to a device which removes the center wire and provides the parts individually at a defined location. The method can be used, for example, in the automatic assembly of compression springs and for automatically feeding springs to a spring end grinding machine.

The DE 2 058 795 describes a device for the thermal post-treatment of coil springs, in which the thermal treatment takes place immediately after the winding without the influence of external stress on the coil springs. This is achieved in that a coil winding machine transporting a coil conveyor conveying means and provided with a tubular channel heating furnace are immediately downstream. As a result, the coil springs can be subjected to the required heat treatment immediately after their winding during a continuous movement in a stress-free state. In one embodiment, the coiled coil springs leave the spring coiling machine via a chute, above which a bristle wheel is arranged, which is driven as a function of the operating speed of the spring manufacturing machine. The chute is followed by a heating furnace with a tubular channel through which the coil springs are pushed by means of the bristle wheel and fall into a container at the end of this channel or are fed to a packaging device.

The DE 1 910 711 describes a method and apparatus for separating and conveying coil springs from a spring coiling machine further processing points. In this case, each cut coil spring is directed at the beginning of a free fall in its path through a controlled directional plate in a designated conveyor trough. The transport of the coil spring to the processing point, such as an automatic grinder, takes place in the conveyor trough by means of a continuously variable electromagnetic drive, on which the conveyors are mounted in a lateral inclination. At the tapered outlet of the conveyor trough the springs fall into a length of the springs to be fitted funnel, which is placed on a sliding tube, in which the spring is guided in vertical alignment with the processing site.

The DE 24 17 685 describes a transport device for coil springs, which is provided in one embodiment, to transport coil springs from a spring capstan to a spring end grinder. The transport device comprises a pneumatic conveyor, which arranged at the beginning of the conveyor line suction device and a subsequent device for conveying the coil springs in the axial direction in the compressed air flow and a subsequent thereto pipeline and at the end of the pipeline before the workpiece holder of the machine and arranged by this having controlled singulation device.

TASK AND SOLUTION

The invention has for its object to provide a method and a system for producing coil springs, which make it possible to produce coil springs in a multi-stage manufacturing process with high productivity and consistently good quality.

To achieve this object, the invention provides a method having the features of claim 1. Furthermore, a system with the features of claim 11 is provided. Advantageous developments are specified in the dependent claims. The wording of all claims is incorporated herein by reference.

First, "raw" coil springs are produced with a defined spring geometry in a conventional manner with the help of an automated spring manufacturing machine by forming and separated from the supplied wire after the forming operation by means of a cutting device. Separated coil springs are then transported to at least one downstream processing station. As an aid to this transport at least one spring transport magazine is used, which has a plurality of prepared receiving spaces for each a single coil spring at defined positions of the spring transport magazine. Several successively provided separated coil springs are distributed by means of a loading device in a placement operation on different receiving locations of the spring transport magazine and transported ordered after completion of this placement operation as a spatially ordered group using the spring transport magazine.

By using suitably designed spring transport magazines, the transport can be made simple and efficient. In addition, this facilitates the assembly of the at least one subsequent processing station, because the coil springs of this processing station can be fed by the spring transport magazine in an orderly form at defined positions. This facilitates the automated assembly of the subsequent processing station. The receiving spaces of the spring transport magazine are designed so that a position-oriented classification of the coil springs is possible. These should be oriented as far as possible axially parallel to each other and kept largely secured against tipping, falling over or rolling away at the receiving place. The design of the recording locations, the positions and orientations of the coil springs are set so that the handling of subsequent handling systems is facilitated.

The receiving locations can be configured, for example, as slots, which provide a receiving space for filling in each case a coil spring. A slot may also have a slip-on with an adapted to the inner contour of aufzusteckenden springs outer contour, on each of which a coil spring can be plugged.

Although it is possible for each of the separated coil springs to be sorted into a spring transport magazine for onward transport, in preferred embodiments, each of the manufactured coil springs is detected by a quality detection system that senses coil springs in response to signals from the quality detection system according to one or more predetermined criteria sorted and only such coil springs are promoted to the spring transport magazine, which meet one or more predetermined criteria. Here, therefore, a sorting of the coil springs between the separation of the supplied wire and the loading of the spring transport magazine. This can be achieved, for example, that the spring transport magazine contains only good parts. Depending on the reproducibility of the original spring production, it may be that not all separated Coil springs enter the spring transport magazine and be transported on to the next processing station. By such an early sorting of coil springs, which do not meet the quality requirements, the transport capacity of spring transport magazines and the processing capacity of downstream processing stations can be used efficiently.

It is also possible to sort coil springs by means of a sorting device in different classes and to transport the coil springs of several classes each with separate spring transport magazines on. For example, coil springs of the desired length and too long coil springs could be sorted via their own feeders in different spring transport magazines.

A spring transport magazine is preferably designed so that the coil springs can be transported with substantially vertical alignment of the spring axes. This makes it possible to accommodate many coil springs relatively close together, so that a high packing density of coil springs in the spring transport magazine can be achieved. In addition, the space required for the individual coil springs in this case is not dependent on the spring length, but oriented solely on the diameter of the coil springs. Spring magazines that can accommodate the coil springs with substantially horizontal alignment of the spring axes are also possible.

In order to achieve a simple and efficient equipping of spring transport magazines, it is provided in some embodiments that the coil springs are aligned substantially vertically by the loading device so that the coil springs can be moved by gravity with a vertical spring axis on or in receiving positions of the spring transport magazine. As a result, separate handling systems, such as grippers or the like, can be dispensed with in the assembly of spring transport magazines in many cases. A vertical orientation of coil springs can also facilitate the transfer to a downstream handling system for equipping a spring transport magazine.

The loading device is preferably configured such that a spring transport magazine can be moved in the loading operation in synchronism with the supply or the supply of coil springs relative to a stationary spring outlet of the loading device such that a free receiving space is provided for each of the conveyed coil springs. For this purpose, a spring transport magazine can be accommodated, for example, on a cross table, which successively positions one receiving station after the other under the spring outlet. Other assembly principles, such as the recording of separated coil springs individually or in groups by means of a gripper system, are also possible.

A spring transport magazine can contain its own safety features to improve process reliability. In some embodiments, the receiving locations of the spring transport magazine are adapted to the geometry of the male coil springs so that incorrectly dimensioned coil springs can not be accommodated. Accordingly, such a spring-specific spring transport magazine can only be equipped with springs of the correct size and / or shape, so that the further transport of wrong parts is prevented.

In order to make optimum use of the transport capacity of spring transport magazines can be provided to equip each of the receiving spaces with a coil spring before the group of coil springs is removed. In some embodiments, however, it is provided that the spring transport magazine is equipped so that at least one receiving space remains free. Often, two, three or four slots remain free. The number of free receiving spaces should be adapted to the transport capacity of subsequent placement devices, to allow that in a subsequent assembly of a downstream processing station initially one or more finished reworked coil springs can be inserted into the spring transport magazine, so that in the spring receiving device of the downstream processing station free Places are created, which can then be fitted individually or in groups with transported coil springs. As a result, the efficiency during loading and unloading of the subsequent processing station can be improved.

In many process variants, the forming operation for producing the (coarse) helical spring is followed by a grinding operation for processing the spring ends in a spring-end grinding machine. The deformed helical springs would therefore have to be transported directly or indirectly, for example with the interposition of a heat treatment operation, to the spring end grinding machine. During transport at least one spring transport magazine is used.

A numerically controlled spring end grinding machine typically has a grinding unit with two axially parallel rotatable grinding wheels, between which a grinding space is formed, as well a loading unit with at least one substantially axially parallel to the grinding wheels rotatable loading plate, which has a plurality of off-axis spring receptacles for receiving a respective helical compression spring. In general, the spring receptacles are arranged in several concentric with the axis of rotation of the loading plate circles in the loading plate.

In such systems, it can be provided that a loading plate of a spring end grinding machine is used as a spring transport magazine or as part of a spring transport magazine. When the cut-off coil springs are sorted directly by the loading device in the loading plate, when loading the Federendenschleifmaschine no conversion of coil springs longer required, so that a faster processing by spring end grinding is possible.

In many cases, it may be expedient if the receiving spaces of the spring transport magazine are distributed according to a rectangular grid on the defined positions. In some embodiments, however, it is provided that a spatial distribution of the defined positions or the receiving positions of the spring transport magazine deviates from a rectangular grid in order to achieve better adaptation to the placement of subsequent processing stations. In particular, the spatial distribution may correspond in groups to the spatial distribution of spring receptacles of a loading plate of a spring-end grinding machine. Then coil springs can be used to convert coil springs from a spring transport magazine in a loading tray of a handling system in groups of two or more coil springs and reacted without changing the spatial relative arrangement of the coil springs in groups in spring receptacles of the loading plate. As a result, an efficient implementation can be achieved with relatively simple handling systems.

In order to facilitate the transfer of coil springs from a spring transport magazine to the intended receiving stations at or in a downstream processing station, it can be provided that a spring transport magazine can be moved from a transport position into a transfer position, wherein in the transport position, coil springs on or in receiving locations, for example mechanically, electrically , are held magnetically or in another way and are released groupwise from the receiving locations in the transfer position. This can be achieved for example by appropriate slide or by a relative rotation of units of the spring transport magazine to each other. It is also possible to assign the holding spaces separate holding elements, which are brought for the transport in engagement with the coil springs to be held and which can be disengaged or disabled for the transfer. For example, it can be achieved that coil springs can fall in groups from a spring transport magazine into an underlying loading plate of a spring-end grinding machine.

Federtransportmagazine can have many different configurations, which can be selected depending on the application. In a simple design, a spring transport magazine can essentially be formed by a torsion-resistant plate in which correspondingly dimensioned receiving bores or recesses for accommodating a respective helical spring are introduced at the defined positions provided for the receiving positions. If the inner diameter of the receiving bore is dimensioned so that a male coil spring largely free of play, but fits without jamming, a reliable removal of the coil springs is possible.

The term "receiving bore" here generally stands for a recess which can be produced by drilling, but possibly also in another way, in a basic body. A receiving bore may have a cylindrical shape, if necessary, other shapes, e.g. with polygonal cross-section, possible.

A spring transport magazine can also be designed as a variable spring transport magazine such that the receiving stations for receiving coil springs with different spring shape and / or size can be converted, preferably without the aid of tools. If, for example, a spring transport magazine has a multiplicity of receiving bores, the size of the receiving opening can be reduced by inserting dimension sleeves into the receiving bores so that even smaller coil springs can fit in reliably and with an anti-tilting effect.

In some embodiments, the spring transport magazine has a grid plate and a plurality of fasteners attachable to the grid plate in different configurations that, when attached to the grid plate in a holding configuration, collectively define the plurality of slots. Such a spring transport magazine can be constructed according to the modular principle. As holding elements, for example, dividers or strips come into consideration, which can be attached to the grid plate with different distances and / or different orientation, and define intermediate compartments that form the receiving places. Retaining elements can also be formed by pins or wire pieces or wire elements, for example, U-shaped can be bent. The holding elements can be plugged into the holes or holes of the grid plate in a suitable spatial arrangement and possibly plugged for a different configuration of recording places.

It is also possible that a spring transport magazine has a carrier plate with a plurality of holding pins at the defined positions of the carrier plate. In order to obtain a variable spring transport magazine, the retaining pin groups can be assigned in each case groups of attachable to a retaining pin holding sleeves with different outer contour. As a support plate, for example, a grid plate with grid holes are used, are screwed into the retaining pin. On the retaining pins holding sleeves of different outer contour can optionally be plugged, which can then act as an inner holder for plugged coil springs.

A spring transport magazine may have a base support with a plurality of receiving holes at the defined positions, wherein the receiving bores are dimensioned for receiving in each case a single helical spring. The inner diameter should be adapted to the outer diameter of the coil spring so that there is little play. The game should typically be smaller than the wire diameter, so that on the one hand easy loading and unloading without jamming is possible, but the coil spring on the other hand with sufficient positional accuracy remains at the defined position to allow further handling using automated handling systems.

In order to enable coil springs of different outer dimensions to be reliably received in a receiving bore, in some embodiments each receiving bore is associated with a spring-loaded retaining element system for centering and fixing coil springs of different shape and / or size in the receiving bore. It may, for example, be two to four radially movable retaining elements, which are themselves designed resilient or loaded with separate springs to hold the type of jaws an inserted coil spring reliably at the defined position can. The holding force can then be easily overcome in a later removal of the coil spring by a handling system.

Spring transport magazines and their components can be made entirely of heat-resistant material, e.g. from a steel material or one or more other metallic materials. For example, a wire basket with suitable compartments could serve as a spring transport magazine. Then it is possible to transport a spring transport magazine with coil springs contained therein into a heat treatment station, e.g. in a tempering furnace. The coil springs may then be e.g. be started in a continuous process. It is also possible to manufacture a spring transport magazine partially or completely made of plastic. If necessary, receiving bores and / or retaining pins can be produced in an injection molding process in one step together with a base carrier. Spring transport magazines can also be made using natural materials such as wood.

The invention also relates to the use of a transport magazine having a plurality of prepared, suitable for receiving a respective coil spring receiving spaces at defined positions of the transport magazine as a spring transport magazine for transporting a group of coil springs from a spring manufacturing machine to at least one downstream processing station of a system for producing coil springs made of wire , The transport magazine may originally have been intended for other purposes. If the recording places are e.g. can be used as a spring transport magazine, if necessary, because of their dimensions for position-locking recording each a coil spring.

The invention also relates to spring transport magazines of the different constructions described in this application.

These and other features will become apparent from the claims but also from the description and drawings, wherein the individual features each alone or more in the form of sub-combinations in an embodiment of the invention and in other fields be realized and advantageous and protectable Can represent versions. Embodiments are illustrated in the drawings and are explained in more detail below.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

1 shows a schematic view of an embodiment of a system for producing helical coil springs with a spring coiling machine, a spring end grinding machine and a transport system for transporting coil springs from the spring coiling machine to the spring end grinding machine;

2 shows in 2A a schematic plan view of the spring coiling machine and associated means for equipping a spring transport magazine, in 2 B a side view and in 2 B a plan view of means for transfer of spring transport magazines between the loading device and a conveyor belt;

3 schematically shows a plan view of a loading plate of a spring end grinding machine, as well as on a handling system which coil springs transported in groups by a spring transport magazine in the loading plate;

4 shows in 4A a fragmentary plan view of an embodiment of a spring transport magazine with receiving holes and spring-loaded holding elements for holding coil springs and in 4B Sectional views of details in the area of a receiving bore;

5 shows in 5A a plan view of another embodiment of a spring transport magazine with a perforated plate and attached separating elements and in 5B an oblique perspective view of the separating elements;

6 shows a side view of an embodiment of a spring transport magazine with retaining pin and diameter sleeves for attaching coil springs;

7 shows a side view of an embodiment of a spring transport magazine with a slider; and

8th shows an embodiment of an adjustable spring transport magazine.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The schematic overview in FIG 1 shows an embodiment of a system 100 for producing coil springs made of wire. The coil springs are also referred to below as "springs"

The system includes an automatic spring manufacturing machine 110 in the form of a computer-numerically controlled spring coiling machine. This one has pick rollers 106 equipped feeding device, the successive portions of a wire from a supply of wire and guided by a straightening unit, not shown wire 104 with a numerically controlled feed rate profile in the horizontal direction in the area of a forming device 108 moves in. The wire is made using numerically controlled tools of the forming device 108 formed in a Federwindeoperation to a helical compression spring F. The forming tools include two angularly offset by 90 °, aligned radially to the desired spring axis numerically controlled wind pens 109 and a pitch tool to numerically control the local pitch of the developing spring at any given time. Furthermore, a cutting device 112 is provided, which separates after completion of a forming operation a finished bent helical compression spring with a vertical working movement of the supplied wire.

The machine axes of the CNC machine belonging to the movable components are controlled by a computer numerical control device 105 controlled.

The spring coiling machine is equipped with a camera-based optical measuring system for the non-contact, real-time acquisition of data on the geometry of a currently manufactured spring. The measuring system includes a CCD video camera 107 , which is installed so that its image field can capture a portion of the developing spring near the tools of the forming device. By means of image acquisition, data about the spring geometry of the spring produced can be determined from the camera images, which are stored in a computer of the control unit 105 be compared with corresponding data for a desired target geometry. As a result, it is possible in a timely manner with the spring production to detect whether the produced spring is a good part (spring geometry in the tolerance range) or a bad part to be sorted out (spring geometry outside the tolerance range). The optical measuring system functions as part of a quality detection system.

The separated coil springs F are after separation from the wire by means of a transport system 120 automatically to a spring-end grinder 190 transported, which is located several meters away from the spring coiling machine and as part of the system 100 performs a downstream machining operation on the supplied coil springs, which is called "spring end grinding". The spring end grinding is known to serve at the spring ends at right angles to the spring axis to create a flat bearing surface for connection body.

This is a vertically constructed spring end grinding machine 190 , which is designed for the dry machining of helical compression springs in the double-sided surface grinding process with unstressed springs in the delivery process. The machine is built in single construction with two grinding spindles and a single loading plate. It essentially comprises a grinding unit 192 and a loading unit 195 , which can be controlled coordinated by means of a control unit, not shown. The grinding unit 192 has two grinding wheels co-axially rotatable by means of suitable drives 193-1 and 193-2 , between which during operation of the machine a grinding room 194 is formed. The variable in height grinding space is limited up and down by the frontal flat surfaces of the grinding wheels. The next to the grinding unit 192 arranged loading unit 195 includes a loading plate 196 by means of a rotary drive about a vertical axis of rotation 197 is rotatable.

As in the top view of 3 can be clearly seen, the loading plate has a variety of off-axis to its axis of rotation arranged spring retainers 198 which are each to receive a single helical compression spring F for processing. The spring mounts are in the example in three concentric rings around the axis of rotation 197 arranged around. The center distance between the center of rotation of the grinding wheels and the axis of rotation of the loading plate is dimensioned such that all spring retainers are transported on rotation of the loading plate about its axis of rotation on a circular arc-shaped grinding track or track through the grinding space between the rotating grinding wheels.

During this rotational movement, the opposite spring ends are ground simultaneously to produce plane contact surfaces. Since the structure and operation of spring end grinding machines are known per se, they will not be further described here.

For transporting in the spring coiling machine 110 produced and then separated from the wire coil springs F to Federendenschleifmaschine 190 is the transport system 120 provided, which for different phases of the transport has different, cooperating devices or subsystems.

The separated coil springs are immediately after detachment from the supplied wire by means of a first transport device 130 to a sorting device 140 promoted with a sorting diverter. The sorting device is activated in response to signals from the camera-based quality detection system via the control device 105 the spring coiling machine activated. In the example, the sorter has two independently electrically or pneumatically pivoted guide plates, which forward the incoming coil springs one of three outlet channels. A middle outlet channel 142 is intended for good parts that meet the quality criteria specified for the desired end product with regard to their geometry (length and / or diameter). Two lateral outlet channels are provided, for example, for too long and too short springs.

Between the forming device 108 and the sorter 140 Devices are provided which help the severed helical compression springs in the rhythm of their creation exactly to the sorter 140 supply and allow a precise control of the sorter.

A guide device has on its side facing the forming tools a trapping section in the form of a funnel, which captures the separated springs and an attached below, slanted guide channel 132 forwarded to the inlet of the sorting gate 140 leads. The guide channel is essentially formed by a cross-sectionally U-shaped component with a smooth, flat or curved bottom on which the springs can slide in the direction of sorting gate, without being able to move laterally. The bottom of the guide channel serves as a guide surface 164 , These devices help to guide the separated springs on their way to the sorting gate, so that each spring is detected by the sorting.

The holding-down device attached to the holder of the cutting tool prevents the spring from jumping upwards so that each spring only has the possibility of flying downwards in the direction of the catching section. The additionally attached hold-down device thus prevents "erroneous" upward and thereby optimizes the production process.

Other facilities will further improve the removal and even more reliable sorting. A significant contribution to this is made by the brush transport device 135 , which contributes to receiving the separated springs and for transporting the finished springs from the area of the forming device. The brush transport device has in the example a single transport brush in the form of a flat belt brush 136 , which is guided in the manner of a conveyor belt over the peripheral surfaces of two pulleys. The belt brush runs upright, the axes of rotation of the pulleys run horizontally, the bristles are directed outwards. One of the pulleys is driven during operation of the spring drum machine not shown brush drive at a continuous speed so that the peripheral speed of the rotating belt is greater than the feed speed of the separated springs. As a result, a molded part accumulation at the inlet of the transport brush can be avoided. In addition, this can be set by a distance between each directly consecutive coil springs to win in continuous operation time for the clocking of the switch and the spring transport magazine or the charging device.

The belt brush has in the area between the pulleys a substantially straight line section, which is parallel to the through the bottom of the guide channel 132 formed guide surface extends at a distance above the guide surface. The tips of the bristles have only a small distance of a few millimeters or centimeters with respect to the parallel, opposite guide surface. This distance is significantly less than the outer diameter of the transported springs. By contrast, the flat belt carrying the bristles has a distance from the guide surface which is significantly larger than the outer diameter of the springs to be transported. This ensures that a spring, which is guided by the catching portion in the space between the belt brush and the guide surface, gently but reliably detected by the bristles of the transport brush and is moved along the guide surface at a well-defined transport speed, which corresponds to the rotational speed of the belt brush , The distance can be adjusted depending on the size of the molded part.

In order to further increase the accuracy of the control of the sorting gate, in the region of the transport path, which is formed between the straight section of the belt brush and the opposite guide surface, a molded part pass sensor is arranged with a light barrier, which generates a pass signal when a coil spring the area of the light barrier happens. Since the distance between the mold part sensor and the inlet of the sorter 140 is known and continue the transport speed of the springs in this area due to the positive guidance by the continuously driven transport brush 136 is exactly known, the switching times for the control movements of the plate-shaped distribution devices can be synchronized with the arrival of the springs exactly, so that a mis-sorting can also be excluded in this respect.

In this embodiment, it is thus possible that the control signal for the sorting gate must also be released via the light barrier integrated in the guide channel, so that the sorting gate can wait until the next spring actually approaches. Switching rhythm and spring flow are synchronized. Embodiments without such a spring pass detection system are also possible.

To the outlet of the canal 142 for the good parts is followed by a loading device 150 to which a second transport device 152 belongs. This is set up for the "good" coil springs behind the sorter 140 initially with horizontal spring axis to promote and then deflect the springs so in the vertical direction, that the coil springs a downward spring outlet 154 the loading device in a vertical orientation, ie with a vertical spring axis, can leave.

The second transport device is also provided with a vertically circulating belt brush 156 equipped as a transport element. This is guided over three guide rollers arranged in triangular arrangement, one of which is controlled by means of a drive via the control device 105 can be driven at a predetermined speed. An upper horizontal rectilinear portion extends below an upper portion of a guide plate 152 , which merges in the area of the front upper deflection roller in a 90 ° circular arc, which is followed by a vertical rectilinear section downwards. The clear distance between the belt brush and the guide plate is practically constant over the entire length of the angled guide plate and dimensioned so that the springs gently, but reliably along the inside of the guide plate initially transported with horizontal spring axis in the horizontal direction of the sorting diverter and then in the vertical Direction to be deflected so that they are the spring outlet 154 can leave with vertical spring axis. In the area of the spring outlet is a pneumatically actuated retaining element, which can temporarily restrain incoming springs before they are released by switching the retaining element at the right time. In these phases of mechanically impeded locomotion of a spring, the flexible bristles of the belt brush may come off the spring or wipe along it, without causing damage to the transport element or the spring. Variants without separate holding elements are also possible.

With the help of the assembly device 150 becomes in the situation shown a spring transport magazine 160 equipped, which is another component of the transport system 120 is and will be described in more detail later.

The facilities that promote the coil springs from the spring coiling machine to the spring transport magazine can be divided into two successive transport subsystems with possibly different or differently adjustable transport speed and thus form a two-part spring transport system. That with the first transport device 130 equipped first subsystem, which is associated with the spring coiling machine and this follows immediately, accelerates the springs quickly away from the machine towards sorter 140 , This avoids backflow in the area of the forming tools. The following behind the sorting device second subsystem, which with the second transport means 150 equipped, brakes the springs and transports the springs only so fast that successively coming springs do not abut each other, but have a small distance from each other. Due to the speed reduction in the second area (behind the sorting device), the spring can be fed to the spring transport magazine with low kinetic energy. A jumping out can be prevented. The second, slower transport subsystem can be modular. Several sub-transport systems can be combined to realize individual transport lengths and routes.

The essentially plate-shaped spring transport magazine 160 has a variety of prepared recording places 162 , in each of which a single coil spring can be accommodated. The seats are located at defined positions of the spring transport magazine and can, as in 2 shown, for example, in a rectangular grid in the form of rectilinear rows and columns are arranged at equal intervals. Other spatial arrangements are possible (see 3 ).

The receiving places are in the example by cylindrical, closed down holes in a steel plate-shaped body 161 formed the spring transport magazine. The bores each have an inner diameter which is slightly larger (for example 0.5 mm to 1.5 mm) than the outer diameter of the male coil springs F. This makes it possible for those through the spring outlet 154 released coil springs alone fall under the effect of gravity from above into the receiving places and there can be largely secured against tilting at a defined position with an accuracy of less than 1 mm position.

The one with the second transport device 152 equipped part of the equipment 150 is fixed in place, leaving the spring outlet 154 is in a fixed position in the room. In order to be able to populate one after another the mutually offset receiving positions of the spring transport magazine, this is on a support plate of a mechanical stage 158 clamped, which serves as part of the loading device to move the spring transport magazine in time with the supplied coil springs relative to the spring outlet in a horizontal plane in two dimensions so that a free receiving space is provided for each of the transported coil springs below the spring outlet before the coil spring through Actuation of the holding element, not shown, from the upper part of the loading device is released by the spring outlet and falls down.

When the desired number of coil springs in the spring transport magazine is reached, the coil springs recorded as a spatially ordered group predominantly by horizontal movement of the spring transport magazine in the direction of Federendenschleifmaschine 190 transported. This is a horizontal conveyor line 170 with an endless circulating conveyor as another component of the system 100 intended.

In the variant of 2 B and 2C become empty Federtransportmagazine by means of a first conveyor belt 171 transported to the area of the cross table. For removal from the cross table 158 to the spring end grinding machine is arranged in a straight line with the first conveyor belt second conveyor belt 172 which leads to the spring end grinding machine. Between these conveyor belts exists in area of the cross table 158 a gap in which the with a support plate 159 equipped part of the cross table can drive. On the support plate is a spring transport magazine. The cross table can in this way empty spring transport magazines from the first conveyor belt 171 pick up, to the loading device 150 transfer and after feeding (filling) back to the conveyor line 170 transport back and to the second conveyor belt 172 to hand over.

It is possible that the conveyor belt will continue to be indexed as soon as the cross table 158 is in a position outside the filling change position and pushes through this clocking the full spring transport magazine in the direction of the spring sanding machine and another, empty spring transport magazine is clocked on the cross table.

It can be provided that the loading device can be clocked via the spring transport magazines. Federtransportmagazine can lie on a clocked conveyor belt and after filling a spring transport magazine, the next clocked in the loading position. For distributing the springs over the various receiving locations, for example, a flexible hose or proboscis or the like may be used, whose inlet end is stationary on the machine side in the region of the spring outlet 154 is located and whose outlet end is clocked in two dimensions horizontally via the spring transport magazines.

With the help of the conveyor belt is a ready-loaded spring transport magazine in the transport direction 121 (Arrow) by rectilinear motion to an area near the spring end grinder 190 transported to an unloading position in which the spring transport magazine is precisely positioned, for example by means of pins and / or stop elements. The spring transport magazine is then located in the working area of a loading and unloading device 180 in the form of an industrial robot whose structure resembles a human arm and which is therefore also referred to as a horizontal articulated arm robot (cf. 3 ). At the free lower end of a vertical articulated arm is a multiple gripper 182 attached, the three synchronously operable gripping elements in the form of electrically or pneumatically actuated inner grippers, which can be synchronously inserted into the interior of three coil springs to be taken and expanded there. The gripping elements are not arranged in a straight row, but according to the arrangement for the corresponding spring retainers 198 in the loading plate 196 mounted in an angled arrangement to each other, so that the gripping elements can each directly equip a group of three substantially radially to each other lying spring receptacles on the loading plate simultaneously. The angled geometry of the three adjacent spring housings can also be found in the positions of the recording positions 362 in the spring transport magazine 360 in 3 again. Due to the design with multiple gripper, the required cycle times during loading and unloading of the loading plate can be reduced.

The number of seats of a spring transport magazine can be at least as large as the number of spring receptacles in the loading plate, so that in a single spring transport magazine all coil springs for complete loading of the loading plate can be provided as an ordered group. In typical embodiments of spring transport magazines, the number of receiving locations depending on the spring geometry is between 30 and 200, in particular between 80 and 150, other numbers being possible.

In preferred method variants, the finished ground helical springs are unloaded from the loading plate in a spring transport magazine and loaded in alternation so new, still to be ground coil springs from the spring transport magazine in the spring receptacles of the loading plate in one operation. For this purpose, it is advantageous if during the loading of the spring transport magazine with uncut coil springs, a number of receiving spaces remains free, which corresponds to the number of simultaneously tangible coil springs, so here three seats. These remain free in the loading on the spring coiling machine receiving spaces are in 3 as a separate group to the left of the multiple gripper 182 shown.

The loading and unloading process on the spring end grinding machine begins with the multiple gripper picking up a group of three finished ground coil springs from the loading plate and depositing them into the free receiving spaces of the spring transport magazine. Thereafter, the multiple gripper seizes three adjacent, still uncut coil springs and transported them as a group to the three just emptied spring receptacles in the loading plate. Thereafter, an adjacent group of ground springs is removed and transported to the spring transport magazine. This alternately unloading and loading is continued until all ground coil springs are removed from the loading plate and the spring seat of the loading plate are newly equipped with untwisted coil springs. The loading plate is rotated cyclically. Thereafter, the ground coil springs can be fed as an ordered group by means of the spring transport magazine to a next processing station while the grinding process for the new springs begins.

Of course it is also possible to use spring transport magazines with smaller transport capacity and to remove the new coil springs from two or more spring transport magazines when fitting a loading plate.

In the 1 to 3 For example, spring transport magazines are shown whose receiving positions have a fixed predetermined receiving dimension and serve as slots for the coil springs to be transported.

It is also possible to use adaptable or variable spring transport magazines, which are suitable for receiving different sized coil springs or can be adapted in a few steps to different dimensions of coil springs.

Based on 4A and 4B is an embodiment of a variable spring transport magazine 460 described, which has a fixed number of receiving spaces, which can accommodate coil springs of different outer diameter reliable and centered with the help of spring-loaded retaining elements. The spring transport magazine has a solid base plate 461 , For example, made of steel, in the evenly spaced cylindrical through holes are introduced, the individual receiving places 462 define. At each bore are three radially spring loaded retaining elements 463 provided, which are arranged at equal angular intervals (120 °) to each other circumferentially offset. Each retaining element is by means of a spring anchored in the base plate 464 spring loaded in the direction of the bore center. These receiving locations can accommodate coil springs of different diameters and geometric shapes (cylindrical, conical, double conical, etc.), since the holding elements can automatically adapt within certain limits to the geometry of the coil springs. As 4B shows, the holding elements are provided on their radial inner sides with inclined surfaces, both during insertion of the coil springs as well as in the removal of the coil springs cause that during an axial movement of the coil spring, the corresponding holding elements can be displaced radially. When inserting the springs, these retaining elements for a short time back and then clamp the inserted coil spring, which is centered by the star-shaped arrangement of the holding elements in the receiving bore. With the help of this principle of the resilient bores an automatic adjustment of the individual recording positions to different spring dimensions is possible within certain limits.

In a non-illustrated embodiment, two diametrically opposed spring-loaded retaining elements are provided, which each have V-shaped notches on the mutually facing, radially inner sides. The holding elements are arranged one above the other in the axial direction of the bore, so that they can be displaced in the radial direction relative to one another in an overlapping manner. Thus, between the mutually facing inner sides of the V-shaped cutouts forms a more or less large, square gap whose size is larger or smaller depending on the radial position of the holding elements. As a result, a centric fixation and holding the coil springs in the manner of a pair of pliers can be realized, which is why this principle is also referred to as a forceps principle.

In the case of 5A and 5B explained embodiment has the spring transport magazine 560 a rectangular base plate 561 in the form of a perforated plate or a grid plate into which a plurality of axially parallel small holes 565 are introduced according to a square grid at close intervals to each other. The holes, whose diameter is substantially smaller than the diameter of the male springs, are used for fastening holding elements 565 in the form of strip-shaped dividers, with different distances and / or different orientation on the base plate 561 can be attached. As a result, different fan sizes can be inserted variably depending on the spring size of the male coil springs. In the example, the resulting subjects or recording places 562 rectangular in cross-section, wherein the inner diameter of the compartments is dimensioned so that it only slightly exceeds the outer diameter of the male coil springs. If coil springs of other dimensions are to be transported, the retaining plates are reconnected to form compartments of suitable size or smaller dimensions.

In 5A compartments of different sizes and shapes are shown to demonstrate that eg non-square compartments are possible. Compartments or receiving openings with different diameters in mutually perpendicular directions may be particularly useful in the transport of coil springs with non-round cross-section, eg magazine springs.

Based on 6 another embodiment of spring transport magazines is explained. In the spring transport magazine 660 are the reception places 662 designed as slip-ons. The spring transport magazine has a plane-parallel base plate 661 in a rectangular grid arrangement, a plurality of vertically projecting, cylindrical holding pins or pins 663 has, which are located at those positions in which the spring axes of the plugged coil springs should lie. The outer diameter of the retaining pin is adapted to the inner diameter of the smallest aufzusteckenden coil springs so that they can be plugged with little lateral play (typically less than 1 mm on the retaining pin.

In order to use the spring transport magazine for coil springs of other dimensions, belongs to the spring transport magazine a set of attachable to the retaining pins holding sleeves 665 , which have a central bore in order to attach the retaining sleeves largely free of play on the retaining pin can. This results in an effective increase in the effective diameter of the retaining pin. The outer diameter of the retaining sleeves is each dimensioned so that a aufzusteckende coil spring essentially without play, but without clamping, can be plugged onto the retaining sleeve from above. The effective diameter of the retaining pin can therefore be varied by attaching additional sleeves.

Based on 7 becomes a spring transport magazine 760 explained, which allows a particularly fast filling of a loading plate of a spring end grinding machine. The spring transport magazine has a base plate 761 with from one to the other plate side continuous cylindrical bores, which at the positions of the receiving places 762 sit or form these. At the bottom is a sliding parallel to the plate plane slider 763 attached, which closes the receiving holes down in the illustrated inserted state. The mounting holes are arranged in the same spatial arrangement to each other as the spring retainers 198 of the to be loaded 196 Charging plate. After loading the spring transport magazine this is transported with a closed slide to be filled to the loading plate and placed above the loading plate so that the central axes of the mounting holes of the spring transport magazine are aligned with the central axes of the underlying spring receptacles of the loading plate. After the correct position is set, the slider will 763 pulled away laterally, so that the mounting holes open down and the coil springs can fall into the spring receptacles of the loading plate. In this way, larger numbers of coil springs can be transferred almost simultaneously from the spring transport magazine to the loading plate in no time.

In 8th is schematically a continuously adjustable spring transport magazine 860 shown in two different usage configurations. The spring transport magazine can be converted or adjusted without the aid of tools for receiving coil springs with different spring shape and / or size. The spring transport magazine has two groups of mutually parallel plate-shaped holding elements, which cross at intersections or come together at the intersection. The holding elements can be connected to one another in an articulated manner at the points of intersection, so that adjacent holding elements of the groups can be pivoted relative to one another. The holding elements limit rhombic receiving places. In the configuration of 8A the holding elements of the groups are perpendicular to each other, so that square receiving seats are formed for springs with a relatively large diameter. In the configuration of 8B opposite side edges of the spring transport magazine are moved parallel to each other, so that oblique diamonds arise with pairs of unequal interior angles. The recording stations can now record feathers with smaller diameters largely free of play.

In the system exemplified here, an automated removal of the coil springs from the spring manufacturing machine in conjunction with a separation of the coil springs and a position-oriented classification takes place in a spring transport magazine. The spring transport magazine can be adapted to the requirements of the subsequent process. The follow-up processes carried out in downstream processing stations may comprise, for example, a heat treatment, a grinding of the helical springs, a shot peening of the helical springs and / or other machining processes en route to the desired end product. When using spring-specific spring transport magazines, the random entry of wrong coil springs into a production order can be prevented, so that process reliability is improved.

As described, a spring coiling machine can be used for spring production as part of the system. Alternatively, it is also possible to use a spring winding machine. In spring winders, the coil springs are formed by winding around a winding mandrel. After completing a forming operation, in either case, a finished coil spring is separated from the supplied wire under the control of an NC control program by a cutter.

Claims (19)

A method of manufacturing wire coil springs, wherein: wire is fed from a wire supply to a numerically controlled spring manufacturing machine, portions of the wire in the spring manufacturing machine are successively deformed into coil springs in a forming operation, each coil spring is separated from the supplied wire after the forming operation and separated coil springs are then transported to at least one downstream processing station, characterized in that for transporting coil springs at least one spring transport magazine is used, which has a plurality of prepared receiving spaces for each coil spring at defined positions of the spring transport magazine, wherein a plurality of successively provided separated coil springs in a loading operation on distributed different recording places and after completion of a placement operation as a spatially ordered group e be transported by the Federtransportmagazins ordered. A method according to claim 1, characterized in that each of the coil springs produced is detected by means of a quality detection system, the coil springs are sorted according to signals of the quality detection system according to one or more predetermined criteria and only such coil springs are conveyed to the spring transport magazine, which meet predetermined criteria. A method according to claim 1 or 2, characterized in that the coil springs are vertically aligned by a loading device such that the coil springs are moved by gravity with a vertical spring axis alone or in receiving locations of the spring transport magazine. Method according to one of the preceding claims, characterized in that the spring transport magazine is moved during the loading operation synchronized with the supply of coil springs relative to a spring outlet of the loading device such that a free receiving space is provided for each of the conveyed coil springs. Method according to one of the preceding claims, characterized in that a spring transport magazine is used in the receiving seats are adapted to the geometry of the coil springs such that incorrectly dimensioned coil springs are not receivable. Method according to one of the preceding claims, characterized in that the spring transport magazine is equipped so that at least one receiving space remains free. Method according to one of the preceding claims, characterized in that adjoins the forming operation for producing the coil spring, a grinding operation for processing the spring ends in a spring end grinding machine, wherein coil springs are transported directly or indirectly using at least one spring transport magazine to the spring end grinding machine. A method according to claim 7, characterized in that a loading plate of the spring end grinding machine is used as a spring transport magazine or part of a spring transport magazine A method according to claim 7, characterized in that a spatial distribution of the receiving locations of the spring transport magazine deviates from a rectangular grid and corresponds to the spatial distribution of spring receiving openings of a loading plate of the spring end grinding machine. A method according to claim 9, characterized in that for converting coil springs from a spring transport magazine into a loading plate coil springs are gripped by a handling system in groups of two or more coil springs and implemented in groups in spring receptacles of the loading plate. A system for producing helical coil springs comprising: a spring manufacturing machine having a feeder for feeding wire ( 104 ) to a forming device ( 108 ), which has at least forming tool for forming the wire into a helical spring, and with a cutting device ( 112 ) for cutting a finished coil spring from the supplied wire after completion of a forming operation; and a transport system ( 120 ) for transporting separated coil springs to a subsequent processing station; characterized in that the transport system has at least one spring transport magazine ( 160 . 360 . 460 . 560 . 660 . 760 ), which has a plurality of prepared receiving places ( 162 . 362 . 462 . 562 . 662 . 762 ) for each one coil spring at defined positions of the spring transport magazine, and that the spring manufacturing machine ( 110 ) a loading device ( 150 ), which is configured to distribute a plurality of sequentially provided separated coil springs to different receiving locations of the spring transport magazine. System according to claim 11, characterized by a sorting device ( 140 ) with a sorting switch, which between the forming device ( 108 ) and the loading device ( 150 ) is arranged and at least one distribution device, which via a control device ( 105 ) of the spring manufacturing machine in response to signals of a quality detection system between different positions is switchable. System according to claim 11 or 12, characterized in that a spring transport magazine as a variable spring transport magazine ( 560 . 660 . 860 ) is designed such that recording places for the reception of coil springs with different spring shape and / or size can be converted, preferably without the aid of tools. System according to claim 13, characterized in that the spring transport magazine ( 560 ) a grid plate ( 561 ) and a plurality of fastened to the grid plate in different configurations holding elements ( 565 ), which after attachment to the grid plate in a holding configuration together the plurality of receiving places ( 562 ) define. System according to claim 13, characterized in that the spring transport magazine ( 660 ) a carrier plate ( 661 ) with a plurality of retaining pins ( 663 ) has at the defined positions of the support plate, wherein preferably the retaining pin groups of attachable to a retaining pin holding sleeves ( 665 ) are associated with different outer contour. System according to claim 11 or 12, characterized in that a spring transport magazine ( 460 ) has a plurality of receiving bores at the defined positions, wherein the receiving bores are dimensioned for receiving in each case a single helical spring, wherein preferably each receiving bore is a system with spring-loaded retaining elements (US Pat. 463 ) is associated with the centering and fixing of springs of different shape and / or size in the receiving bore. System according to claim 11 or 12, characterized in that a spring transport magazine ( 760 ) is convertible from a transport position into a transfer position, wherein in the transport position Coil springs on or in receiving places ( 762 ) are kept and released in the transfer position from the receiving places. Use of a transport magazine with a plurality of prepared, each for receiving a coil spring receiving slots at defined positions of the transport magazine as a spring transport magazine for transporting a group of coil springs from a spring manufacturing machine to at least one downstream processing station of a system for producing helical coil springs. Spring transport magazine ( 160 . 360 . 460 . 560 . 660 . 760 ) with a large number of prepared places ( 162 . 362 . 462 . 562 . 662 . 762 ) for each a coil spring at defined positions of the spring transport magazine, wherein the spring transport magazine is characterized by the features of the characterizing portion of at least one of claims 13 to 17.

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