JP2001071080A - Production of oval coil spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coil spring having excellent elastic effect by accommodating an original spring, in which a wire is coiled in several times to a prescribed coil diameter/pitch and has a round cross sectional shape, in a female die, pressing/deforming with using a male die fitting into the female die between the male/female dies in the direction orthogonal to the coil axis and making an oval shape having a large diameter at a center part and a small diameter at both ends. SOLUTION: By coiling a wire to a fixed coil diameter in plural times, an original coils spring 15 having a round cross section is formed, is accommodated in a die recessed part 21 of a female die 20 and is pressed with using a male die 30 fitting into the die recessed part 21 between female/male both dies in the direction orthogonal to the coil axis. The original spring 15 is deformed lat and is formed to an oval shape having a large diameter at the center part and a small diameter at both ends. Tension is applied to an oval coil spring, the torsional deformation generated to a coiled surface is eliminated by deforming the cross section from a round shape to an oval shape, successively, by quenching, an oval coil spring having a fixed pitch is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elliptical coil spring manufactured by winding a wire a plurality of times at a predetermined winding diameter and pitch, and a method for manufacturing the same.

[0002]

2. Description of the Related Art There is a coil spring of this type, which is generally called "Hako-spring". The Hako-spring has such a shape that the cross section of the coil portion is elongated and looks "box-shaped". (See FIG. 8). Hako spring d is used, for example, as a spring for pressing an elongated article such as a bullet, or in the field of toy guns, for pressing a bullet floor of a spherical bullet called a BB bullet. In the latter case, the bullets can be fed side by side in a zigzag manner (referred to as double columns), so that a larger number of bullets can be stored in the magazine g (FIG. 9). When this is performed with a normal round spring, it is necessary to pressurize the feed floor f with a stronger spring to push up two rows of bullets, and the round spring may bend (FIG. 10).
(A)), the contact size of the round spring becomes longer and the number of bullets becomes smaller (FIG. 10 (b)).

[0003] However, a problem with the Hako spring is that the manufacturing cost is several times or more that of the round spring. A device as shown in FIG. 6 is used for the manufacture of a box spring. In this device, a wire h is supplied to a cored bar i, and the cored bar i is used as a bending die, and one side is pressed by a press die k. After the preliminary bending, the main bending, and the feeding of the bending portion, the preliminary bending and the main bending of the other bending portion are performed (FIG. 7), so that the bending process must be repeated twice or more in total. Since such steps must be performed, the efficiency of manufacturing the box spring cannot be improved, and there is a limit in cost reduction. Therefore, the price is about ten times as expensive as the round spring.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above points, and its object is to provide a coil having a slender cross-sectional shape capable of exhibiting an elastic effect equivalent to that of a Hako spring. It is to provide a new coil spring. Another object of the present invention is to provide a method for efficiently manufacturing a novel coil spring.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an elliptical coil spring in which the cross section of the coil portion has an elliptical shape having a large diameter at the center and small diameters on both sides. It is. This elliptical coil spring is formed by winding a wire a plurality of times at a predetermined winding diameter and pitch to form an original coil spring having a circular cross-sectional shape. Using a mold, the original coil spring is crushed flat by applying pressure between the male and female molds in a direction substantially perpendicular to the coil axis, and the cross-sectional shape is transformed into an elliptical shape with a large diameter at the center and small diameters on both sides It is desirable to manufacture by doing. The elliptical cross-sectional shape can then be increased in pitch and further quenched.

[0006]

DETAILED DESCRIPTION OF THE INVENTION An elliptical coil spring according to the present invention
It is a kind of coil-shaped spring produced by winding a wire a plurality of times at a predetermined winding diameter and pitch.

The elliptical coil spring according to the present invention has an elliptical shape in which the cross section of the coil portion is large at the center and small on both sides (FIGS. 1 and 2 (c)). In general, an ellipse is sometimes confused with an oval, and it can be said that the horizontal cross-sectional shape of a box spring manufactured by the apparatus shown in FIGS. 6 and 7 corresponds to the oval. The ellipse in the present invention does not need to satisfy the condition of the ellipse defined by the geometry, but it does not need a straight line portion such as an ellipse, and may be considered to consist of a continuous curve.

By making the cross-sectional shape of the coil portion elliptical, a wide range of spring force can be applied in the same manner as a plurality of round springs arranged in parallel. Also, if a plurality of round springs are arranged in parallel, each round spring will work independently,
According to the elliptical coil spring of the present invention, a plurality of round springs are operated by a single spring, so that the acting force does not become uneven.

In order to efficiently manufacture such an elliptical coil spring, in the method of the present invention, an original coil spring having a circular cross-sectional shape is formed from a wire rod, and a step of processing the original coil spring is performed. It may be considered that the process of winding the wire a plurality of times at a predetermined winding diameter and pitch to form the original coil spring is the same as a conventional round spring.

The original coil spring is housed in a female mold, and is subjected to plastic working using a male mold that fits in the female mold, between the male and female molds, in a direction substantially perpendicular to the coil axis. Therefore,
It is necessary that the wire rod undergoes plastic deformation by processing. When a material that is not quenched and that can be quenched in a later step is used, the wire and quenching conditions may be the same as those generally used in spring manufacturing. Mild steel wire is one such material, but stainless steel wire is not hardened.

The coil axis is an axis extending in the winding direction of the coil, and the direction perpendicular to the coil axis is the direction of the winding diameter in the cross section of the coil, so that the original coil spring is crushed flat. As a result, the cross-sectional shape is transformed into an ellipse having a large diameter at the center and a small diameter on both sides. In other words, a large diameter has a small curvature, and a small diameter has a large curvature.

In the present invention, the elliptical coil spring will be described mainly with respect to the compression spring, but it can be used as a tension spring. In the case of a compression spring, an intermediate product of an elliptical coil spring deformed into an elliptical shape has a predetermined natural length by expanding the winding pitch by applying a tensile force in the coil axis direction, and further having a predetermined natural length. It becomes a spring. The predetermined winding diameter and pitch indicate that the winding diameter and pitch are constant, but this may be provided in the main part of the spring, and does not need to be the same at both ends.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the illustrated embodiments. FIG. 1 shows an elliptical coil spring 10 according to the present invention.
Is most simply shown. This elliptical coil spring 10
It has an elliptical cross-sectional shape with a large diameter at the center portion 11 and small diameters at both end portions 12 and 13. This coil spring 10 also has a constant pitch p (FIG. 2 (c)). However, the spring end 14 is processed according to the place where the spring is used, the purpose of use, the use, and the like. That is, any form of spring end 14
Can have The illustrated example intends to use the elliptical coil spring 10 as a compression spring, and has a spring end 14 that is substantially perpendicular to the coil axis A so that the compression member can be in contact with the entire end surface.

Such an elliptical coil spring 1 according to the present invention.
0 is processed according to the steps shown in FIGS. 2 (a), 2 (b) and 2 (c). That is, the wire is wound a plurality of times with a constant winding diameter R to form the original coil spring 15 having a circular cross section (FIG. 2A). Next, the formed original coil spring 1
5 is placed in the mold recess 21 of the female mold 20, and the original coil spring 15 is pressed between the male and female molds in a direction substantially orthogonal to the coil axis A using the male mold 30 fitted in the same mold recess 21. A flat crushed product 16 can be formed.

At the stage of the plastic working of the original coil spring 15, even if the third die is inserted into the original coil spring 15, the male mold 30 molds the original coil spring 15 in the female mold 20. good. Accordingly, since the molding pressure can be received by the third mold, excessive deformation can be prevented and a certain shape can be easily provided. The specific shape and method of providing the insert type are determined according to the purpose.

At this stage, the product 16 is still in FIG.
Similarly to the above, the initial winding state is maintained, but the cross-sectional shape is changed from a circular shape to an elliptical shape by the above-mentioned processing, so that the peripheral length is changed, and a slight twist deformation is caused on the winding surface (FIG. 2 (b)) is not shown). However, this torsional deformation disappears by the tensile processing on the product 16, and is further quenched to complete the compression spring 10 composed of an elliptical coil spring having a constant pitch p. The product 16 is processed into an elliptical cross-sectional shape, which is almost the same as the elliptical shape of the final product (10), but is considered to be slightly flattened due to the tensile processing. The compression spring 10 thus obtained has an elliptical cross-section with a large diameter at the center 11 and small diameters at both ends 12,13. The elliptical coil spring is considered to have a somewhat different spring constant in comparison with a round spring obtained by processing the same original coil spring.

When a wire made of stainless steel or a wire made of copper alloy or the like is used as a material, the elliptical coil spring according to the present invention is completed without quenching the product 16. Further, in the case of using a tension spring, the elliptical coil spring according to the present invention is completed without processing for expanding the pitch.

[0018]

Since the present invention is constructed and operates as described above, it is possible to provide a novel elliptical coil spring capable of exhibiting an elastic effect equivalent to that of a Hakospring. As described above, a long working time is not required, and it is possible to produce the sheet with very high efficiency mainly by press working. For this reason, the manufacturing cost is about a fraction of that of the Hakobane, and the performance is not different from that of the Hakobane.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of an elliptical coil spring according to the present invention.

FIG. 2A is a cross-sectional view and a side view of an original coil spring. (B) Cross-sectional view and side view of an intermediate product. (C) Cross-sectional and side views of the final product.

FIG. 3 is a perspective view of an apparatus used for manufacturing the present invention.

FIG. 4A is a cross-sectional view of a state where an original coil spring is set in a female mold. (B) A longitudinal sectional view of a state where the original coil spring is set in a female mold.

FIG. 5A is a cross-sectional view of a state where an original coil spring is crushed. (B) A longitudinal sectional view of a state where the original coil spring is crushed.

FIG. 6 is an explanatory view showing an example of a device for manufacturing a box spring.

FIG. 7 is an explanatory view showing a manufacturing process of the box spring.

FIG. 8 is a perspective view showing an example of a box spring.

FIG. 9 is a perspective view showing a usage example of a box spring;

FIG. 10A is a perspective view showing a usage example of a round spring. (B) A perspective view showing an example of use of a round spring.

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[Procedure amendment]

[Submission date] June 20, 2000 (2006.2.
0)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Method of manufacturing it if elliptical coil [Title of the Invention]

[Claims]

1. A method of manufacturing a spring having a coil portion formed by winding a wire a plurality of times at a predetermined winding diameter and pitch and having a cross section of an elliptical shape, wherein the wire has a predetermined winding diameter and pitch. The original coil spring having a circular cross-sectional shape is formed by winding a plurality of turns, and the original coil spring is housed in a female mold and a male mold that fits into the female mold is used. A method for manufacturing an elliptical coil spring, characterized in that the original coil spring is crushed flat by applying pressure in an orthogonal direction, and the cross section is deformed into an elliptical shape having a large diameter at the center and small diameters at both sides.

2. A crushed raw coil spring flattened to deform the cross-sectional shape to an oval composed of small diameter larger sides at the central portion, an ellipse according to claim 1, wherein subsequently characterized by enlarging the pitch Manufacturing method of coil spring.

3. A crushing raw coil spring flatly, claim 1 to deform the cross-sectional shape to an oval composed of small diameter larger sides at the central portion, characterized by further quenching
Or a method for manufacturing an elliptical coil spring according to 2 .

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to guess if elliptical coil which is manufactured wound plural times the wire to a predetermined winding diameter and pitch
And a method for producing the same.

[0002]

2. Description of the Related Art There is a coil spring of this type, which is generally called "Hako-spring". The Hako-spring has such a shape that the cross section of the coil portion is elongated and looks "box-shaped". (See FIG. 8). Hako spring d is used, for example, as a spring for pressing an elongated article such as a bullet, or in the field of toy guns, for pressing a bullet floor of a spherical bullet called a BB bullet. In the latter case, the bullets can be fed side by side in a zigzag manner (referred to as double columns), so that a larger number of bullets can be stored in the magazine g (FIG. 9). When this is performed with a normal round spring, it is necessary to pressurize the feed floor f with a stronger spring to push up two rows of bullets, and the round spring may bend (FIG. 10).
(A)), the contact size of the round spring becomes longer and the number of bullets becomes smaller (FIG. 10 (b)).

[0003] However, a problem with the Hako spring is that the manufacturing cost is several times or more that of the round spring. A device as shown in FIG. 6 is used for the manufacture of the box spring. In this device, a wire h is supplied to a metal core i, and the metal core i is used as a bending die, and one side is formed by a press die k. After the preliminary bending, the main bending, and the feeding of the bending portion, the preliminary bending and the main bending of the other bending portion are performed (FIG. 7), so that the bending process must be repeated twice or more in total. Since such steps must be performed, the efficiency of manufacturing the box spring cannot be improved, and there is a limit in cost reduction. Therefore, the price is about ten times as expensive as the round spring.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above points, and its object is to provide a coil having a slender cross-sectional shape capable of exhibiting an elastic effect equivalent to that of a Hako spring. to provide a method for producing good performance index novel coil spring with.

[0005]

Means for Solving the Problems] To solve the above problems, the present invention, since the cross sectional shape of the coil portion, to provide an elliptical coil spring having an elliptical consisting small diameter larger sides at the central portion The wire is wound a plurality of times at a predetermined winding diameter and pitch to form an original coil spring having a circular cross-sectional shape, and the original coil spring is housed in a female mold and a male mold that fits into the female mold is used. Manufactured by compressing the original coil spring flat by applying pressure between the male and female molds in a direction substantially perpendicular to the coil axis, and transforming the cross-sectional shape into an ellipse with a large diameter at the center and small diameters at both sides. It is desirable to do. After changing the cross-sectional shape to an oval shape, take measures to expand the pitch and further harden it
It is a thing .

[0006]

DETAILED DESCRIPTION OF THE INVENTION An elliptical coil spring according to the present invention
It is a kind of coil-shaped spring produced by winding a wire a plurality of times at a predetermined winding diameter and pitch.

The elliptical coil spring according to the present invention has an elliptical shape in which the cross section of the coil portion is large at the center and small on both sides (FIGS. 1 and 2 (c)). In general, an ellipse is sometimes confused with an oval, and it can be said that the horizontal cross-sectional shape of a box spring manufactured by the apparatus shown in FIGS. 6 and 7 corresponds to the oval. While satisfying the condition need not of ellipse defined by the geometric oval in the present invention, have name also mean that requires linear portion such as oval.

By making the cross-sectional shape of the coil portion elliptical, a wide range of spring force can be applied in the same manner as a plurality of round springs arranged in parallel. Also, if a plurality of round springs are arranged in parallel, each round spring will work independently,
According to the elliptical coil spring of the present invention, a plurality of round springs are operated by a single spring, so that the acting force does not become uneven.

In order to efficiently manufacture such an elliptical coil spring, in the method of the present invention, an original coil spring having a circular cross-sectional shape is formed from a wire rod, and a step of processing the original coil spring is performed. It may be considered that the process of winding the wire a plurality of times at a predetermined winding diameter and pitch to form the original coil spring is the same as a conventional round spring.

[0010] The original coil spring housed in the female, with a full male fitting in the female, is pressurized in a direction substantially perpendicular to the coil axis at between male and female mold undergoes plastic working. Therefore, it is necessary for this wire to undergo plastic deformation by processing. When a material that is not quenched and that can be quenched in a later step is used, the wire and quenching conditions may be the same as those generally used in spring manufacturing. Mild steel wire is one such material .

The coil axis is an axis extending in the winding direction of the coil, and the direction perpendicular to the coil axis is the direction of the winding diameter in the cross section of the coil, so that the original coil spring is crushed flat. As a result, the cross-sectional shape is transformed into an ellipse having a large diameter at the center and a small diameter on both sides. In other words, a large diameter has a small curvature, and a small diameter has a large curvature.

In the present invention, the elliptical coil spring will be described mainly with respect to the compression spring, but it can be used as a tension spring. In the case of a compression spring, an intermediate product of an elliptical coil spring deformed into an elliptical shape has a predetermined natural length by expanding the winding pitch by applying a tensile force in the coil axis direction, and further having a predetermined natural length. It becomes a spring. The predetermined winding diameter and pitch indicate that the winding diameter and pitch are constant, but this may be provided in the main part of the spring, and does not need to be the same at both ends.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the illustrated embodiments. FIG. 1 shows an elliptical coil spring 10 according to the present invention.
Is most simply shown. This elliptical coil spring 10
It has an elliptical cross-sectional shape with a large diameter at the center portion 11 and small diameters at both end portions 12 and 13. This coil spring 10 also has a constant pitch p (FIG. 2 (c)). However, the spring end 14 is processed according to the place where the spring is used, the purpose of use, the use, and the like. That is, any form of spring end 14
Can have In the illustrated example, the elliptical coil spring 10 is intended to be used as a compression spring, and has a spring end 14 that is substantially perpendicular to the coil axis A so as to be able to contact the compression member at all end faces.

Such an elliptical coil spring 1 according to the present invention.
0 is processed according to the steps shown in FIGS. 2 (a), 2 (b) and 2 (c). That is, the wire is wound a plurality of times with a constant winding diameter R to form the original coil spring 15 having a circular cross section (FIG. 2A). Next, the formed original coil spring 1
5 as shown in FIG. 3 and FIG.
5 using a male mold 30 that fits into the same type recess 21 .
By applying pressure between the male and female molds in a direction substantially perpendicular to the coil axis A, a product 16 in which the original coil spring 15 is squashed flat can be formed as shown in FIG.

At the stage of the plastic working of the original coil spring 15, even if the third die is inserted into the original coil spring 15, the male mold 30 molds the original coil spring 15 in the female mold 20. good. Accordingly, since the molding pressure can be received by the third mold, excessive deformation can be prevented and a certain shape can be easily provided. The specific shape and method of providing the insert type are determined according to the purpose.

In FIG . 2B , the product 16 is still in FIG.
As in (a), the initial winding state is maintained, but the cross-sectional shape is changed from a circular shape to an elliptical shape by the above-mentioned processing, so that the peripheral length is changed and a slight twist deformation is caused on the winding surface. are (not shown in Figure 2 (b)). However, this torsional deformation disappears by the tensile processing on the product 16, and is further quenched to complete the compression spring 10 composed of an elliptical coil spring having a constant pitch p. The product 16 is processed into an elliptical cross-sectional shape, which is almost the same as the elliptical shape of the final product (10), but is considered to be slightly flattened due to the tensile processing. The compression spring 10 thus obtained has an elliptical cross-section with a large diameter at the center 11 and small diameters at both ends 12,13. The elliptical coil spring is considered to have a somewhat different spring constant in comparison with a round spring obtained by processing the same original coil spring.

When a wire made of stainless steel or a wire made of copper alloy or the like is used as a material, the elliptical coil spring according to the present invention is completed without quenching the product 16. Completing an elliptical coil spring also that by the present invention without the processing of the pitch expansion in the case of a further tension spring.

[0018]

Since the present invention is constructed and operates as described above, it is possible to provide a novel elliptical coil spring capable of exhibiting an elastic effect equivalent to that of a Hakospring. As described above, a long working time is not required, and it is possible to produce the sheet with very high efficiency mainly by press working. For this reason, the manufacturing cost is about a fraction of that of the Hakobane, and the performance is not different from that of the Hakobane.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of an elliptical coil spring according to the present invention.

FIG. 2A is a cross-sectional view and a side view of an original coil spring. (B) Cross-sectional view and side view of an intermediate product. (C) Cross-sectional and side views of the final product.

FIG. 3 is a perspective view of an apparatus used for manufacturing an elliptical coil spring according to the present invention.

FIG. 4A is a cross-sectional view of a state where an original coil spring is set in a female mold. (B) A longitudinal sectional view of a state where the original coil spring is set in a female mold.

FIG. 5A is a cross-sectional view of a state where an original coil spring is crushed. (B) A longitudinal sectional view of a state where the original coil spring is crushed.

FIG. 6 is an explanatory view showing an example of a device for manufacturing a box spring.

FIG. 7 is an explanatory view showing a manufacturing process of the box spring.

FIG. 8 is a perspective view showing an example of a box spring.

FIG. 9 is a perspective view showing a usage example of a box spring;

FIG. 10A is a perspective view showing a usage example of a round spring. (B) A perspective view showing an example of use of a round spring.

Claims (4)

[Claims] 1. A coiled spring produced by winding a wire a plurality of times at a predetermined winding diameter and pitch, wherein the cross-sectional shape of the coil portion is large at the center and small at both sides. An elliptical coil spring characterized by having: 2. A method of manufacturing a spring having a coil portion having an elliptical cross section, which is produced by winding a wire a plurality of times at a predetermined winding diameter and pitch, wherein the wire is wound at a predetermined winding diameter and pitch. A plurality of turns to form an original coil spring having a circular cross-sectional shape, and enclose the original coil spring in a female mold and use a male mold that fits into the female mold. A method for manufacturing an elliptical coil spring, characterized in that the original coil spring is crushed flat by applying pressure in directions substantially orthogonal to each other, and the cross section is deformed into an elliptical shape having a large diameter at the center and small diameters at both sides. 3. The elliptic according to claim 2, wherein the original coil spring is crushed flat, the cross-sectional shape is deformed into an ellipse having a large diameter at the center and small on both sides, and thereafter the pitch is increased. Manufacturing method of coil spring. 4. The method according to claim 2, wherein the original coil spring is crushed flat, the cross-sectional shape is transformed into an elliptical shape having a large diameter at the center and a small diameter at both sides, and further quenching.
Or a method for manufacturing an elliptical coil spring according to item 3.