RU2373016C1 - Assembly for winding steel springs - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: assembly consists of installed on base unit of wound material supply, also material is supplied in form of steel rod, of inductor for rod heating located on case of unit of wound rod supply along axis of supply, of rotating mandrel with rotation drive and axial transfer drive in form of driven screws and nut and of cooling device. The rotating mandrel is arranged horizontally, and the cooling device is made in form of a sprayer installed on the base coaxially with the rotating mandrel at a distance from a wound coil of the spring determined in dependence on value of mandrel supply for each grade of spring steel.

EFFECT: raised efficiency of process of fabrication of large dimension steel springs of hot winding and increased operation life of springs.

2 cl, 1 dwg

Description

The invention relates to mechanical engineering technology and can be used for the production of large-sized steel springs of any design - cylindrical, conical, with pinched and unpressed turns, etc., obtained by hot winding.

A device for winding springs is known, comprising a feed assembly of the material to be mounted mounted on a bed and mounted to move along a circular path centered on the winding site, a heating assembly, a cooling bath and a vertical mandrel with a rotation and axial movement drive in the form of a copying device (see St. USSR No. 1348040, class B21F 3/04, claimed 1982.06.16, publ. 1987.10.30).

A disadvantage of the known device is its low productivity due to the need for sequentially performing winding operations, holding in the quenching bath and returning the mandrel with the spring to the spring removal zone before starting to wind the new spring.

Closest to the proposed technical essence, selected for the prototype, is an assembly for winding springs, mounted on a bed, with the ability to change the angle between them, a rotating vertical mandrel with an axial displacement drive, a feed unit for winding material, a heating unit located on the unit body supply of winding material along the feed axis, a cooling bath located on the bed in the place of lowering the mandrel, and the feed node is placed in the guides of the bed with the ability to move along to angular path with a center in the place of winding by means of a power cylinder, and the drive axial movement of the mandrel is made in the form of a drive screw and nut (see ed. St. USSR No. 816634, class B21F 3/04, announced 04/14/77, publ. 30.03. 81).

The disadvantage of the prototype is also its low productivity due to the fact that the winding of a new spring is possible after sequential passage through the previous spring of the operations of winding, cooling with holding in the bath and returning to the starting position. The use of unregulated cooling in the bath in this device makes the strength and geometric characteristics of the spring unstable along the length of the spring.

The technical problem solved by this invention is to increase the productivity of the manufacturing process of large-sized steel springs by hot winding with increased and stable strength and geometric characteristics along the spring length.

The stated technical problem is solved due to the fact that in the unit for winding steel springs containing a feed assembly of the material to be wound in the form of a steel bar, an inductor for heating the bar placed on the casing of the wire feed unit along the feed axis, a rotating mandrel with a rotation drive and axial movement in the form of a drive screw and nut, a cooling device. The rotating mandrel is located horizontally, and the cooling device is made in the form of a sprayer placed coaxially with the rotating mandrel at a distance from the winding coil of the spring, depending on the magnitude of the mandrel feed for each grade of spring steel, providing post-injection shutter speed necessary to complete the polygonization adjustment of the structure, formed during the winding process.

In this case, the sprayer can be made sectional.

The drawing shows a kinematic diagram of the inventive device.

The unit contains a drive 2 for feeding the material to be mounted mounted on the bed 1 — a steel bar, an inductor 3 for heating the bar under winding, a guide sleeve 4 for the moving bar, a rotation and axial movement unit 5 of the spindle 6 with a hollow mandrel 7. A gripping mechanism is located inside the hollow mandrel 7 the front end of the bar, equipped with a tooth 8. The node 5 of rotation and axial movement of the spindle 6 with the mandrel 7 includes a rotation mechanism 9 with an electric motor 10, a spline sleeve 11 and a lead screw 12, as well as a mechanism 13 with an electric motor 1 4 and a nut 15 for changing the axial displacement in accordance with the pitch of the turns of the winding spring. The magnitude of the axial displacement in one revolution - the supply of the mandrel, equal to the distance between the turns of the spring (winding step), is provided by the ratio of the rotational speeds of the screw 12 and nut 15, which are set by the program of the command device 16. A cooling device 17 is installed coaxially with the mandrel 7 on the bed, a sprayer, which occurs rotational cooling of the coil spring as it enters the device. The sprayer 17 is installed on the bed at a distance from the place of formation of the coil of the winding spring, which depends on the size of the mandrel for each type of spring steel. This distance should provide post-wound shutter speed required to complete the polygonization restructuring of the structure formed during the winding process.

The sprayer 17 can be made sectional (as shown in the drawing), which allows the use of different cooling media in each section, performing cooling with different intensities in the temperature ranges of the spring cooling process, for example, accelerated cooling at high temperatures and slowed down to prevent cracking in the interval martensitic transformation.

The unit works as follows,

At the initial moment, the mandrel 7 is in the extreme right position, while the tooth 8 of the capture of the end of the bar is located on the supply line of the bar, which is tangential to the outer surface of the mandrel. The rod enters the rollers of the feed unit 2, moves through the inductor 3 at a speed sufficient to warm the rod throughout the volume to a temperature that homogenizes the high-temperature phase of the steel in carbon and alloying elements. A rod through the guide sleeve 4 enters between the mandrel 7 and the tooth 8, the electric motor 10 of the rotation mechanism 9 and 14 of the movement mechanism 13 are turned on, providing a predetermined spring winding step. In this case, the spindle 6 with the mandrel 7 receive rotation from the mechanism 9 of the rotation of the mandrel by means of a spline connection 11, and the axial movement corresponding to the step of winding the spring, by connecting the screw 12 and nut 15. There is a winding of the spring. Upon completion of the movement of the rod through the inductor 3 upon reaching the set heating temperature, the inductor is turned off. The winding spring is rotational, continuously with an axial displacement equal to the winding pitch, together with the mandrel enters the sprayer 17, ensuring the same time interval before the start of cooling of each coil. By placing all the turns of the spring in the sprayer 17, the command device 16 gives a command to release the mandrel 7 from the spring and accelerate the return of the mandrel to its original position. The spring remains in the sprayer 17. The winding cycle is repeated. At the end of the stroke of the mandrel 7 with a new coil spring, the remaining from the previous cycle of the spring is ejected from the sprayer 17 and replaced with a newly wound spring. This cycle repeats further - each subsequent spring pushes the previous one.

During hot winding of the spring along the diameter of the rod, plastic deformation occurs, thermomechanical hardening occurs, in order to maintain and maintain its stability along the length of the spring, cooling of each coil of the spring should begin after a constant time from winding of the coil, determined by the chemical composition of the material (steel). Before the start of cooling, the polygonization restructuring of the steel substructure should be completed, and with rotational quenching, constancy of the dynamic strength and geometric characteristics along the spring length is ensured. The necessary and constant time before the start of cooling of each coil of the spring is provided by placing a cooling sprayer at a distance from the winding coil, depending on the size of the mandrel feed.

The operation of the unit was tested during winding of springs made of steel 60S2A. A bar with a diameter of 15 mm was heated in the inductor by high-frequency currents to a temperature of 1000-1050 ° C. After winding each coil, its cooling began in 15 seconds and until it was completely quenched. Springs of diameter 70-100 mm were wound. Measurement of the inter-turn gap (winding step) after a trial draft until the spring turns come into contact has shown that its value fluctuates within ± 0.1 mm (10 mm pitch). This, as well as the constancy of the fine-grained polygonized structure over all the turns of the spring indicate the constancy of the properties along the entire length of the spring.

Measurement of the inter-turn gap for springs manufactured in known installations where the entire spring is quenched, after 20-30 seconds after winding it, showed that the fluctuations in the inter-turn gap after trial draft are 2-3 mm at a winding pitch of 10 mm.

The durability of the springs manufactured on the claimed unit, during fatigue tests was 3-5 times higher than that of springs made on known units.

Thus, the inventive unit for winding steel springs in comparison with the prototype provides increased productivity, increased and constant along the length of the spring level of quality and dynamic strength, which increases the durability of the manufactured springs.

Claims (2)

1. A unit for winding steel springs, comprising a feed assembly of a winding material mounted on a bed in the form of a steel bar, an inductor for heating the bar, placed on the casing of a feed assembly of a winding rod along the feed axis, a rotating mandrel with a rotation drive and an axial displacement drive in the form of a drive screw and nuts, a cooling device, characterized in that the rotating mandrel is located horizontally, and the cooling device is made in the form of a sprayer placed on the frame coaxially with the rotating mandrel n distance from the wound spring coil, which depends on the magnitude of feed mandrels for each grade of spring steel secured poslenavivochnoy exposure required for complete poligonizatsionnoy adjustment structure formed in the process of winding. 2. The unit according to claim 1, characterized in that the sprayer is made sectional.

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