RU2003416C1 - Method of manufacturing springs with non-circular cross-section of wire - Google Patents

Description

crumple the spring billet and subject it to wiring.

When crimping, the workpiece wire is between the punch 3, plate 2 (Fig. 2, c), the surface of the cage and the surface of the inner mandrel inserted into the mold (the mandrel is shown by a dashed line, see Fig. 2, c). Moreover, the cylindrical surface of the inner mandrel and the holes of the casing are located coaxially, coaxially, with an equal gap on the sides. The diameter of the mandrel on which the billet wire is wound, and the diameter of the inner mandrel are equal or close. The diameters of the frame and the holes of the mold differ by an amount equal to (2 b). where b is the width of the coil of a non-circular spring profile.

There is a small and equal gap on both sides between the workpiece and the side surfaces. By varying the gap, for example, by changing the diameter of the mandrel or wire, the value b (and hence e) of the spring coil profile is controlled, so as to create a controlled closed volume for deformation of the workpiece material, i.e. prerequisites for producing springs of varying stiffness.

Typically, the diameter of the mandrel is (DCp - b), and the diameter of the hole of the mold holder (Dcp - b). When crimping, an internal mandrel is used, which is constantly located in the holder, or a short mandrel with a wound wire (see Fig. 2, b). The length of the inner mandrel is greater than the height of the wound wire-workpiece. As a rule, blanks for crimping are obtained from multi-turn blanks of large length, from which blanks of the required height are cut, and the ends are ground out.

The created conditions of plastic deformation in a closed volume lead to some difficulties and increased friction against the walls of the cage and mandrel. For favorable plastic deformation, special lubrication, heating in the treatment zone and other means, for example, the application of ultrasonic vibrations, are necessary.

In the manufacture of springs from round wire with a diameter of 5-8 mm without lubrication, heating and ultrasound, unevenness in thickness a of the coil of the spring is often observed. The spread reaches 10-22%. Moreover, the contribution of factors is almost the same. No lubrication - the variation in a is 8-10%. there is no heating or ultrasonic exposure - the parameter is non-uniform and is 5-8% of each factor. Special solid lubricants and deformers of several stages reduce unevenness to small values, but this is due to the technological difficulties of producing flat springs.

Exposure to heating and ultrasound allows controlling the structure of the material 5 of the spring. This affects its performance. Together, these factors increase the cyclic resistance of the springs by 10-20%. Therefore, the application of ultrasonic vibrations and heating, performed at the 0 stage of crimping, are the features of the method, they contribute to the creation of highly resistant springs.

The choice of wiring method depends on the type of springs, production traditions, and the degree of automation of the process.

When wiring a screw (Fig. 2,3), the workpiece, screw, or both the screw and the workpiece rotate. The screw is a rod with a helical surface. Diameter

0 The shaft is smaller than the internal diameter DBH of the spring. The protruding screw surface is made with a certain pitch. Taking into account the stresses in the spring, subsequent relaxation and greening

5, it is necessary that the step of the helical surface is slightly larger than the step of the spring being produced, but in any case, the step should not be less than the step of the coil required by the spring drawing.

0 Depending on the diameter of the spring, ratios (bx), friction conditions during wiring, the screw surface protruding above the shaft is made rectangular, inclined or trapezoidal

5 shapes similar to the lead screws of metal cutting equipment.

The wiring method (Fig. 2, e) consists in the fact that initially the wedge is inserted between the turns

0 spring blanks. The spring is rotated around its axis and fed to the desired step. To reduce wear, the wedge reciprocates relative to the axis of the spring. As a rule, due to the tilt of the turns, the wedge is located at a certain angle to the axis of the spring.

When wiring with a rotating disk or several disks (Fig. 2f), the latter are inclined relative to the axis of the spring. The spring is rotated and shifted. They are ready to drive, the drives are autonomous. The disk system (or spring) makes a movement similar to the movement of the machine support when threading with a given step.

In all cases, ample lubrication is required during wiring.

PRI me R. From a wire 51 KhFA 14963-78 of circular cross section with a diameter of 4.0 mm, a spring blank is wound onto a cylindrical mandrel with a diameter of 9.8 mm. Then the workpiece is deformed in the mold with a compressive force Q 467 kI and a spring is obtained, the turns of which after wiring have a non-circular profile with parameters ai 2 mm, bi 4.5 mm. The spring is opened by a screw with a pitch of 5.4 mm. Obtaining a spring with the same parameters by the prototype method is extremely difficult (bending a strongly elongated section).

After deformation of the round billet wire with a force of Q 300 kN, the profile with parameters ai 1.5 mm, b1 5.2 mm is studied.

The application of great effort in the compression allows you to get even more flattened coil. It is impossible to obtain a spring with such a wire profile by the prototype method; In addition, the inner hole will be tapered.

The springs according to the known method (without crimping) were made from a Hput-shaped rectangular profile by winding with a given step. The cross-sectional size of the coil of spring (Lx) for experiments No. 33.6 was 3.6 mm. for experiments No. 4-3.0 -3.0 mm.

The manufactured springs according to the proposed method (with winding and crimping) had the parameters shown in the table, series 1 and 2. The parameters of the series 2 and 4 springs, including the cross-sectional area, are almost the same, the difference is in the Q manufacturing methods, and therefore the spring resistance is different. At

of the proposed method, the performance of the springs is 2.5 times higher. Note that Opar is 18.4 mm, Oen is 9.8 mm, and t is 5.4 mm. The tests established the following: under more stringent conditions (freedom length Ho 45 mm to 77 mm, cross-sectional area 9.0 mm2 to 12.9 mm2) springs made by the proposed method (series 1) work even at 48% compression from size But with a cycle of 5.2-105 moves;

springs made by the known method No. 3. only with 28 compression have worse cyclicities - 4.8-10J strokes.

Thus, the application of the proposed method improves the durability

springs nz35-52%, reduce the mass and dimensions respectively in 2.0 and 1.7 times in comparison with springs made according to the traditional prototype method. Springs made according to the proposed

method, they can work with large technological efforts and in more stringent conditions without loss of performance.

(56) Copyright certificate of the USSR No. 1266623. cl. At 21 F 35/00. 1986.

Claims (1)

1. METHOD FOR MANUFACTURING SPRINGS WITH A CIRCULAR SECTION OF WIRE about several cuts, including winding of coils of wire, forming by crimping a non-circular profile of a cross-section of coils by crimping a blank on a stamp having a mold, wiring the spring and heat treatment, characterized in that it is wound by mandrels, and the turns on the latter have a close, plastic deformation of the workpiece material carry out along the coaxial surfaces of the mandrel and the holder of the mold, equally spaced along the entire contour from each other by a size corresponding to the thickness of the cross section of the coil created by crimping the spring; moreover, at the stages of forming a round cross-section of the spring coil in the interrogation zone, the workpiece is heated and ultrasonic vibrations are applied, and the resulting spring-workpiece is wired using means to obtain a specific spring pitch. 35