JPH03189036A - Manufacture of tapered coil spring - Google Patents

Abstract

PURPOSE:To efficiently form the spring by forming a hardened tapered wire having repeatedly a tapered part, and subsequently, bringing it to tempering and feeding it to a spring forming device, and forming continuously the spring. CONSTITUTION:An element wire W fed from a supply device 1 is heated by a heating device 2b, tension is applied thereto by a tension roller 2d, quenched by cooling 2c and a hardened tapered wire TW having repeatedly a tapered part is formed. In a tempering furnace 3, the hardened tapered wire TW from a taper forming device 2 is brought to tempering continuously. Subsequently, while giving prescribed tension by a pair of constant torque pinch rollers 4, the tempering processing is executed, and after the wire is adjusted to a pre scribed temperature by a temperature regulating device 7, it is cut separately as a tapered spring stock TR by a running cutting machine 8. Next, it is fed into a buffer device 5 through a guide pipe 9, and a transfer speed is converted and adjusted. By a spring forming device 6, the stock TR is formed successively to a barrel-like tapered coil spring TS.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a tapered coil spring used as a suspension spring for a vehicle such as a passenger car.

[Conventional technology]

In recent years, tapered coil springs with nonlinear characteristics have been widely used as suspension springs to improve ride comfort, running stability, vehicle posture, etc. of passenger cars and railway vehicles.

Previously, in manufacturing these tapered coil springs,
A wire rod or steel bar of the same diameter is cut using a beering process or a swaging process to create a material with tapered parts at both ends, and this material is hot or cold spring-formed.
A method was adopted in which the material was then subjected to quenching and tempering treatments.

However, with these conventional manufacturing methods, the material yield during taper processing is low, and coil springs with complex shapes such as barrel springs may be deformed during heat treatment after spring forming. This method has drawbacks such as the need to add additional steps, resulting in low productivity and high costs.

From this point of view, a temperature gradient in the axial direction is applied to a steel material of the same diameter, such as a wire rod or a steel bar, using an appropriate heating means, and the difference in plastic deformation based on this temperature gradient is used to perform dieless elongation of the temperature gradient part. A method (Japanese Patent Application Laid-open No. 5816728) was developed to obtain a material with a tapered part by rolling the material. By continuously applying partial heating and tension to the wire, and then cooling it, it is formed into a hardened tapered wire having repeated tapered parts, and then tempered in-line. An apparatus (Japanese Patent Application Laid-Open No. 60-56416) has been developed to efficiently obtain heat-treated chill-by four filaments having repeated taper parts. Tapered coil springs formed by spring-forming in between are in practical use.

[Problem to be solved by the invention]

However, the device following R in the prior art (Japanese Unexamined Patent Publication No. 6
According to No. 0-56416), a long tapered filament as a material can be obtained at low cost, but by continuously forming a spring using this tapered filament, the productivity can be further increased. This leads to the following problems.

In other words, when a long tapered filament is used as a raw material, the tapered filament is used in a coiled state, so when it is continuously formed into a spring, In this case, it is necessary to straighten the coil after it has been wound into a coil.

Since these tapered filaments have repeated tapered parts and have unequal diameters in the axial direction, if they are wound into a coil as they are, they will have a tendency to wind better than the narrow diameter part. Is the packaging of the coil circular? Because it is a stiff chick, it is usually wound with a bend in the large diameter part, and it is also heat-treated, so it is not easy to straighten these parts, and it is relatively large. Because it requires strength,
This correction requires a special correction device.

On the other hand, in order to eliminate the need for straightening, if the unit is cut in a straight line without being wound up with a winder and then used, the units Due to length restrictions, bundling, packaging, transportation,
Not only does unpacking become complicated, but also the problem arises that continuous spring forming cannot be carried out efficiently and the chicks cannot be formed.

In view of the problems mentioned in 2., the present invention has been developed by winding a tapered wire as a continuously manufactured material into a coil shape,
It is an object of the present invention to provide a method for manufacturing a T-bafil spring, which can be continuously formed into a spring without straightening it into a straight shape, and which can greatly improve its productivity.

[Means to solve the problem]

In order to achieve the above object, the present invention has the following configuration. Zunawaji, the method for manufacturing a tapered coil spring according to the present invention is to apply heat and tension to a continuously fed wire, and then rapidly cool it, thereby forming a quenched coil spring having repeated tapered portions. The tapered filament that has been formed into a finished tapered filament and subsequently tempered is fed to a spring forming device via a buffer device, and is continuously heated by the residual heat from the tempering process. It is spring-formed.

[Effect]

In the method for manufacturing a tapered coil spring according to the present invention,
The continuously fed wire is formed into a hardened tapered filament having repeated taper parts, and then the tempered tapered filament is fed to a spring forming device to continuously form the wire. Since the material is spring-formed, it is possible to perform efficient spring-forming without winding the tapered wire as a material into a coil or forming it into a straight C2 curve.

Also, since the spring forming is performed warmly using residual heat from the tempering process, it is possible to form the spring with a relatively low force.
- In addition, the shape and dimensions of each spring after molding can be made highly accurate with little variation.

Additionally, there is a difference in the time required between the process of forming a wire into a heat-treated tapered filament and the process of spring forming this tapered filament, and the time required for spring forming is usually shorter. However, in the present invention, the tempered Cheapai single filament is fed to the spring forming device through the buffer device, so the buffer device absorbs the difference in the required time and produces a continuous and efficient spring. Can be molded.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual explanatory diagram of a manufacturing facility for a taper coil spring according to an embodiment of the present invention. In FIG. The strands W are sequentially unwound and fed continuously.

(2) is a taper forming device, the taper forming device F
(2) is a constant speed feed roller (2a
), a heating device (2b), a cooling device (2C), and a tension roller (2d).
The heating device (2b) applies heat to the strand W sent from 1), and the tension roller (2d) applies tension in the direction of the arrow in the figure, followed by the cooling device (2).
By rapid cooling in step c), the wire W is formed into a hardened tapered filament TW having repeated tapered portions, as shown in FIG. 2a.

The taper forming device (2) is also equipped with a non-contact dimension measuring device and display means (not shown here), which are used to measure the dimensions of the tapered filament formed and to measure the dimensions of the tapered filament. As shown in Figure a, markings M are made to indicate the positions to be cut at each boundary of the tapered spring material.

(3) is a tempering furnace, and the tempering furnace (3) is a normal continuous heat treatment furnace, which is disposed following the taper forming device (2), and is used for quenching from the taper forming device (2). Finished tapered filament T
- is continuously tempered. In addition, a tempering furnace (
3) A pair of constant torque pinch rollers (4) disposed on the exit side of the tempering furnace (3)
It is tempered under constant tension and continuously fed out with high straightness.

(5) is a buffer device, the buffer device (5)
is disposed at the rear of the exit side of the tempering furnace (3), and includes a plurality of pairs of feed rollers (5a) whose rotational speeds can be changed and adjusted.

Further, between the buffer device (5) and the tempering furnace (3), a temperature control device (7) equipped with a cooling means and a traveling cutting machine (8) are installed in order from the side of the tempering furnace (3). ) and a guide pipe (9) are arranged, and the heat-treated tapered wire wire continuously sent out from the tempering furnace (3) is kept within a predetermined range by the temperature control device (7). After the temperature is adjusted, the tapered spring material TR is individually cut by a traveling cutting machine (8) as shown in FIG. sent to,
The transfer speed is converted and adjusted within this buffer device (5).

(6) is a spring forming device, the spring forming device (6)
is arranged at the rear of the outlet side of the buffer device (5), and stores the tapered spring material TR that is individually and intermittently fed from the buffer device (5) into a barrel as shown in FIG. 2C. These are sequentially formed into a tapered coil spring TS having a shape.

On the other hand, the tapered filament T is sent out from the tempering furnace (3)
The temperature at 14 varies depending on the size, material, molding conditions, etc., but the temperature during spring forming by the spring forming device (6) is preferable in order to increase the precision of the shape and dimensions of each spring after forming (for example, 400 to The temperature is adjusted by the temperature control device (7) so that the temperature range is approximately 450°C.

In addition, the forming speed of the taper forming apparatus (2) in this embodiment varies depending on the size and material of the wire, the shape of the tapered part to be formed, etc., but is approximately 20 to 30 seconds per tapered spring material TR. Comparison, spring forming equipment (6)
The forming speed is 5 to 1 per tapered coil spring TS.
It is about 3 times faster at about 0 seconds, but the difference in forming speed between the two is due to the individual cutting by the traveling cutting machine (8) and the conversion and adjustment (mainly acceleration) of the transfer speed by the buffer device i (5). be compensated.

Here, a mark detector 0 is installed on the entry side of the traveling cutting machine (8).
1), and upon receiving the electrical signal from the mark detector 00, the traveling cutting machine (8) moves to follow the movement of the tapered filament T-, and locates the mark M shown in FIG. 2a. Cut securely. In addition, two tip detectors 021 and θ are disposed on the inlet and outlet sides of the buffer device (5), respectively, to detect the entry and exit of the tapered spring material TRO into the buffer device (5), and the spring A tip detector 04 is also arranged on the entrance side of the molding device (6), and these tip detectors 021.0ω, 04
Electric signals from the feed roller (5a) of the buffer device (5) are sent to a control device (not shown), and control signals from the control device based on these electric signals control the rotational speed of the feed roller (5a) of the buffer device (5). , spring forming equipment (6
) is adjusted and set.

In the manufacturing method of the tapered coil spring of this embodiment based on the equipment configuration and manufacturing procedure described above (1 year, after obtaining a tapered wire as a raw material continuously from a strand of equal diameter, ζ, Tapered coil springs can be obtained efficiently, and the manufacturing process requires (4) coil winding, straightening, etc.
Processing of the culm is not required at all, and productivity can be greatly increased.

In addition, in the taper coil spring manufacturing equipment B1- of the embodiment described in 10, the forming speed of the taper forming device (2),
The difference in forming speed with the spring forming device (6) is compensated by individual cutting of the tapered spring material by the traveling cutter (8) and conversion/adjustment of the individual transfer speed by the buffer 5R (5). and 62, but this is a conceptual explanatory diagram of another aspect (as shown in Figure 3, a tempering furnace (3)! followed by a temperature control device (7), and a spring forming device i) f ( 6
), instead of installing the traveling cutting machine (8) and the Hanosoa device (5) of the configuration shown in the first part, a horizontal loop type looper 00 is installed between the incinerator ( The tapered filament TW sent out from 3) can be configured to be continuously fed to the spring forming device (6) without being cut individually. Furthermore, as shown in FIG. 4, which is a conceptual explanation of yet another aspect of the invention, a vertical loop type looper surface comprising a pitch P and a dancer roller 0 is provided, and the tempering is performed. It is also possible to have a configuration in which the tapered line TW sent out from the furnace (3) is continuously fed to the spring forming device IG) without being cut individually.

Here, in the example in which the configuration shown in FIG. 3 is adopted, the tapered filament TW is looped in an arc shape, so it is intended for a relatively small diameter one, and the minimum radius of the loop forming the arc shape is is set so that the stress caused by bending does not exceed the elastic limit of the heat-treated tapered filament.

In addition, in the example in which the configuration shown in Figures 3 and 4 is adopted, the length of the bobber-attached filament at its shortest in each looper 05) and Q7) (in Figures 3 and 4) is The length of the tapered filament TW+ shown by the solid line), the length when it is looped at its longest length (the length of the tapered filament TW shown by the two-dot chain line in Figs. 3 and 4), The relationship between the above-mentioned taper forming device (2) 2: Spring Forming W (
6). In addition, in these examples, as shown in Figures 3 and 4, , 2. A mark detector 0ω is arranged on the entry side of the spring-molded W (6), and this mark detector 0ω detects the 4' mark M indicating the cutting position attached to the tapered filament TW, Based on the electric signal, the cutter (6a) built into the spring-molded cutter (6) cuts the pieces individually.

When adopting the configurations of these examples, the equipment configuration becomes simpler and the power required is lower than that of the configuration in which the traveling cutter (8) and buffer device (5) shown in FIG. 1 are provided. I can do it.

〔Effect of the invention〕

As described above, according to the method for manufacturing a T-V coil spring according to the present invention, a tapered filament as a continuously formed material can be wound into a coil shape or straightened into a straight shape. It is possible to form springs continuously and efficiently without any process, and the productivity can be greatly improved.

[Brief explanation of drawings]

Fig. 1 is a conceptual explanatory diagram of a manufacturing facility for a taper coil spring according to an embodiment of the present invention, Figs. A conceptual explanatory diagram of a taper coil spring manufacturing equipment DU1 according to another embodiment of the present invention. FIG. 4 is a conceptual explanatory diagram of a taper coil spring manufacturing equipment according to still another embodiment of the present invention.

Claims (1)

[Claims] The continuously fed wire is heated and stretched, and then rapidly cooled to form a hardened tapered wire having repeated tapered portions, followed by tempering treatment. A method for manufacturing a tapered coil spring, characterized in that the tapered filament is fed to a spring forming device via a buffer device, and is continuously spring-formed in a warm state using residual heat from the tempering process.