JP4454110B2 - Synthetic resin coil spring manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing method capable of efficiently and continuously manufacturing a synthetic resin coil spring in which short cylindrical seats are integrally connected to both ends.
[0002]
[Prior art]
Conventionally, coil spring manufacturing methods include a method of winding a wire rod around a rotating rod body at a predetermined pitch, a method of integrally forming with a mold, and the like. In addition, there is a problem that it cannot be efficiently manufactured. Therefore, the inventors of the present application have developed a synthetic resin coil spring manufacturing method as described in Japanese Patent Publication No. 6-49342.
[0003]
In other words, the synthetic resin coil spring is manufactured by rotating the cutter around the synthetic resin tube at the exit of the die against the synthetic resin tube extruded from the extruder. The coiled wire is continuously cut and then cooled, and this manufacturing method has an advantage that a synthetic resin coil spring can be efficiently manufactured with a simple device.
[0004]
[Problems to be solved by the invention]
However, according to the method of manufacturing the synthetic resin coil spring, the synthetic resin tube extruded from the extruder is formed into a continuous long coiled filament. After that, when the coiled wire is cut in a direction perpendicular to the center line and cut into a synthetic resin coil spring having a predetermined length, both ends of the coil spring are gradually thinned toward the tip. In addition, there is a possibility that the end portion may be lost during handling or use, and it may not be able to be used. In addition, the spring characteristics and the spring constant with other parts are different, and the stretch is uniform over the entire length. There is a problem that it becomes impossible to exhibit the sex.
[0005]
Furthermore, when mounting on various devices, devices, tools, etc., the seating on the mounting seat surface is poor, and even if a washer is used, there is a possibility that it will be in an unstable mounting state and it will be difficult to achieve an accurate spring action. is there.
[0006]
The present invention has been made in view of such problems. The object of the present invention is to form a short cylindrical seat that can be stably mounted without forming both ends of the coil spring. the synthetic resin coil spring comprising Te simple and to provide a manufacturing method of efficiently be prepared synthetic resin coil spring.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a synthetic resin coil spring manufacturing method according to claim 1 of the present invention is a method in which a synthetic resin tube extruded from an extruder is inserted into a cutter at the die outlet of the extruder. A process of continuously cutting into a coiled wire having a predetermined length by rotating around a synthetic resin tube, and after forming the coiled wire, the cutter is moved backward to move the synthetic resin tube. A step of forming a cylindrical portion of a predetermined length continuous with the coiled wire by extruding from the extruder as it is, and after forming the cylindrical portion, the cutter is advanced again and extruded from the extruder. The step of continuously cutting the tube made of synthetic resin into a coiled wire having a predetermined length is repeated, and the coiled wire and the tube portion that are alternately connected are cooled, and then the tube portion is Its head Successively in the direction of the middle portion, sequentially to the coil spring portion consisting of the coiled filament of predetermined length which are provided integrally short cylindrical seat at each end by cutting, and forming.
[0008]
In the method for manufacturing a synthetic resin coil spring, the invention according to claim 2 is a method of arranging a pair of cutters on both sides of the die outlet of the extrusion molding machine and extruding the synthetic resin tube extruded from the extrusion molding machine. It is characterized by cutting into a double coil spring part.
[0009]
[Action]
Synthetic resin coil springs are provided with a short cylindrical seat at both ends so that they are easy to handle and are not easily damaged, and can be used for a long time. It can be easily and stably attached to equipment, devices, tools, and the like, and the coil spring can exhibit uniform elastic expansion and contraction over the entire length. In addition, a screw or a locking groove for connection or attachment can be formed on the outer peripheral surface or inner peripheral surface of the short cylindrical seat at both ends, which can be used for convenience.
[0010]
In order to continuously manufacture such a synthetic resin coil spring, the synthetic resin tube is extruded at a predetermined extrusion speed by an extruder, and the die outlet is placed between the inner and outer peripheral surfaces of the synthetic resin tube. When the cutter is rotated in the circumferential direction of the synthetic resin tube in a state where the blade portion is passed through, the synthetic resin tube is continuously cut in a spiral shape and formed into a coiled filament. After the coiled wire is formed for a predetermined length, when the cutter is retracted, a spiral groove whose depth of cut with respect to the synthetic resin tube being extruded from the extruder is gradually reduced becomes the synthetic resin. It leaves | separates from the outer peripheral surface of a synthetic resin tube, forming in the outer peripheral surface of the tube made from.
[0011]
Thus, when the cutting action by the cutter on the synthetic resin tube is stopped for a certain period of time, the synthetic resin tube is extruded as it is from the extruder during that time, and the cylindrical cylindrical portion continuous to the coiled filament is formed. It is formed. After the cylindrical part is formed for a predetermined length, when the cutter is advanced toward the synthetic resin tube continuously extruded from the extrusion molding machine, the spiral of the synthetic resin tube gradually deepens by the cutter. After the groove is cut and formed, the cutter penetrates the synthetic resin tube, and the coiled filament is continuously formed in the same manner as described above.
[0012]
After the synthetic resin tube extruded from the extrusion machine is cooled while being continuously and alternately formed into a predetermined length of coiled filament and a cylindrical portion connected to the coiled filament, the cylindrical portions are sequentially When cut in a ring shape from the intermediate portion in the length direction, the above-described synthetic resin coil spring having a constant diameter and a fixed length, which is integrally provided with a short cylindrical seat at both ends, can be obtained. The length of the spring part and the short cylindrical seat part of this synthetic resin coil spring is determined by the cutting and forming time of the coiled filament due to the advance of the cutter with respect to the synthetic resin tube extruded at a predetermined extrusion speed from the extruder. It can be adjusted according to the cut-off time due to the stoppage.
[0013]
Further, in the method of manufacturing a coil spring made of synthetic resin, as described in claim 2 , a synthetic resin extruded from an extruder by arranging a pair of cutters on both sides of the die outlet of the extruder. Manufactures synthetic resin coil springs in which the end of each coil spring part is connected to both sides on the diameter line of the opposing surface of the short cylindrical seat part by cutting the tube made into a double coil spring part Therefore, it is possible to provide a synthetic resin coil spring that exhibits more stable attachment and spring action.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, specific embodiments of the present invention will be described with reference to the drawings. FIGS. 1 and 2 show a coil spring A made of synthetic resin having a predetermined length and a predetermined diameter, which is constant over the entire length. The same synthetic resin short cylindrical seat 4B ′ formed at the same diameter as the outer diameter of the synthetic resin coil spring portion 4A ′ at both ends of the synthetic resin coil spring portion 4A ′ formed at the inner and outer diameters , 4B 'is formed by continuously connecting these short cylindrical seats 4B' and 4B 'with the center of the coil spring portion 4A' being aligned with the center line of the synthetic resin coil spring 4A '. Both ends of the coil spring 4A ′ are connected to the outer peripheral ends of the opposed surfaces of the short cylindrical seats 4B ′ and 4B ′.
[0015]
The manufacturing method of the synthetic resin coil spring having such a structure will be described. FIG. 3 shows a manufacturing apparatus of the synthetic resin coil spring. Reference numeral 1 denotes an extrusion molding machine, which is made of a cylindrical molten synthetic resin. A synthetic resin tube 4 having a constant diameter and a constant thickness is extruded from a die 3 provided with an extrusion passage 2 downward at a constant extrusion speed.
[0016]
Reference numeral 5 denotes a ring-shaped rotary cutter base which is rotatably mounted around the die 3 via a bearing 10 on the outer peripheral surface of the lower end portion of the die 3, and is mounted with an advancing / retreating mechanism 7 of the cutter 6 and its outer peripheral surface. A gear 8 is formed on the die 3, and the gear 8 is meshed with a small gear 11 fixed to a rotation shaft of a drive motor 9 installed on one side of the extruder 1, and the drive motor 9 surrounds the die 3. Is configured to be driven to rotate.
[0017]
The advancing / retracting mechanism 7 of the cutter 6 is composed of a cylinder mounted at an appropriate position on the lower surface of the rotary cutter base 5 toward the inner and outer diameter directions of the die 3, and a cutter mounting bracket 12 is attached to the tip of the piston rod 7a facing outward. The base end portion of the cutter 6 is fixed to the cutter mounting bracket 12, and the blade portion 6a of the cutter 6 is disposed along the lower surface of the die 3 so as to advance and retract in the inner and outer diameter directions of the die 3. ing. The advance / retreat mechanism 7 is not limited to the above-described cylinder, and an appropriate mechanism such as a mechanism for advancing / retreating the cutter 6 by rotating a screw rod can be employed.
[0018]
A cooling water tank 13 is provided below the extruder 1 and is continuously extruded from the extrusion passage 2 of the die 3 of the extruder 1 with its water surface close to the lower surface of the die 3 of the extruder 1. The synthetic resin tube 4 is cooled. In addition, an abutment 14 having an outer diameter that is substantially the same as the inner diameter of the synthetic resin tube 4 is suspended from the central portion of the extruder 1 so as to be immersed in the cooling water tank 13. In the cooling water tank 13, the metal wire 14A is slid in contact with the outer peripheral surface of the coiled wire 4A spirally cut by the cutter 6 on both sides of the wire 14 in the center. Rotating rollers 15 and 15 that are pulled downward using 14 as a guide are pivotally supported.
[0019]
Further, the inside of the metal 14 is formed into a hollow 16, and the cooling water in the cooling water tank 13 is taken into the hollow part 16 and penetrates from the hollow part 16 toward the outer peripheral surface of the metal 14. The inner peripheral surface of the synthetic resin tube 4 on the metal 14 or the inner peripheral surface of the coiled wire 4A formed by cutting the synthetic resin tube 4 in a spiral shape with a cutter 6 through a plurality of small-diameter holes 17. Is configured to cool. Further, although not shown in the drawing, the cooling water tank 13 is formed in a U-shaped cross section, and a synthetic resin coil spring 40 that is continuously manufactured by cooling the coiled filament 4A is passed through an appropriate guide roll. A predetermined portion of the synthetic resin coil spring 40 that is passed through the cooling water tank 13 and pulled out from the cooling water tank 13 is sequentially cut at predetermined lengths by a cutting blade (not shown).
[0020]
Next, a method of manufacturing a synthetic resin coil spring using the apparatus configured as described above will be described. A semi-molten synthetic resin tube 4 is extruded from the extrusion passage 2 of the die 3 at a constant extrusion speed from the extruder 1 and the advancing / retracting mechanism 7 of the cutter 6 is contracted to cause the cutter 6 to move to the synthetic resin tube 4. When the cutter base 5 is rotated at a predetermined speed by the drive motor 9 in a state of being penetrated to the inside, the synthetic resin tube 4 rotates along the lower surface of the die 3 immediately before entering the cooling water tank 13. The cutter 6 is continuously cut into a coiled wire 4A having a constant width (constant thickness) according to the extrusion speed of the synthetic resin tube 4.
[0021]
The coiled wire 4A is immediately received on the metal 14 and the metal 14 slides downward on the metal 14 while holding the inner diameter of the coiled wire 4A at a constant diameter. The coiled wire 4A is forcibly sent downward at a speed higher than the extrusion speed of the extrusion molding machine 1 by the rotating rollers 15 and 15 disposed on the outer side of the rotating machine 15, and the rotating rollers 15 and 15 rotate. A coiled wire 4A having a coil pitch corresponding to the speed is formed. Then, after the coiled wire 4A passes through the rotary rollers 15 and 15, it is cooled and fixed with the coil pitch.
[0022]
After the coiled filament 4A is formed for a predetermined length, when the advancing / retreating mechanism 7 is operated to retract the cutter 6 from the synthetic resin tube 4 in the outer diameter direction, the tip of the synthetic resin tube 4A is formed. The formation of the coiled wire 4A is finished when the synthetic resin tube 4 is retracted from the inner peripheral surface into the synthetic resin tube 4, and the synthetic resin tube is further moved as the cutter 6 is retracted to the outer peripheral surface of the synthetic resin tube 4. The depth of cut with respect to 4 gradually decreases, and the spiral groove 41 is formed on the outer peripheral surface of the synthetic resin tube 4, leaving the outer surface of the synthetic resin tube 4 outward. The spiral groove 41 is formed between the circumference of the synthetic resin tube 4 and less than one circumference.
[0023]
Thus, when the cutting and processing of the coiled filament 4A by the cutter 6 with respect to the synthetic resin tube 4 extruded from the extrusion molding machine 1 are not performed, the synthetic resin tube 4 is cut and formed first. After the wire 4A, it is continuously extruded from the extrusion molding machine 1 as it is, and is fed onto the metal 14 in the cooling water tank 13 while being formed in the cylindrical part 4B connected to the coiled wire 4A.
[0024]
When the cylindrical portion 4B having a predetermined length is formed by the synthetic resin tube 4 continuously extruded from the extruder 1 into the cooling water tank 13, the cutter table 5 is rotated again at a predetermined rotational speed. Then, the advancing / retreating mechanism 7 is operated to allow the cutter 6 to penetrate from the outer peripheral surface of the synthetic resin tube 4 toward the inner peripheral surface. Until the insertion of the cutter 6 reaches the inner peripheral surface of the synthetic resin tube 4, a spiral groove 42 whose depth of cut gradually increases is formed on the outer peripheral surface of the synthetic resin tube 4. When the spiral groove 42 is formed in the circumferential length portion of the synthetic resin tube 4 that is less than one circumference, the cutter 6 penetrates to the inner peripheral surface of the synthetic resin tube 4 and is continuously extruded from the extruder 1. The resin tube 4 is cut into a coiled wire 4A as described above.
[0025]
Then, when the coiled filament 4A is formed to a predetermined length, the cutter 6 is moved backward from the synthetic resin tube 4 again in the same manner as described above, so that the coiled filament 4A with respect to the synthetic resin tube 4 is retreated. The forming process is stopped, and the synthetic resin tube 4 continuously extruded from the extrusion molding machine 1 is sent out to the cooling water tank 13 as it is to form a cylindrical portion 4B having a predetermined length. Note that the length of the cylindrical portion 4B can be set by the length of the rest time of the cutter 6 and the extrusion speed of the synthetic resin tube 4 from the extrusion molding machine 1.
[0026]
In this way, the synthetic resin tube 4 continuously extruded from the extruder 1 at a constant extrusion speed is cooled while being alternately formed into the coiled filament 4A and the cylindrical portion 4B for each predetermined length. By cooling and solidifying the inside of the water tank 13 while proceeding, the coiled wire 4A is made into a coil spring part 4A ', and this coil spring part 4A' and the cooled cylindrical part 4B are continuously connected from the cooling water tank 13. As shown in FIG. 4, each cylindrical body portion 4B is sequentially divided from the middle portion in the length direction into a ring shape, that is, in a direction perpendicular to the center line of the coil spring 40, as shown in FIG. As shown in FIG. 2, a synthetic resin coil spring A having a constant diameter and a predetermined length, in which short cylindrical seat portions 4B 'and 4B' consisting of half of the cylindrical body portion 4B are integrally provided at both ends. Are manufactured in large numbers.
[0027]
The constant length synthetic resin coil spring A thus obtained is used in a state in which the annular end faces of the short cylindrical seats 4B 'and 4B' at both ends thereof are in close contact with the seating surface. If necessary, a connecting portion or an engaging portion such as a screw or a cut may be formed on the outer peripheral surface or inner peripheral surface of the short cylindrical seat portions 4B ′ and 4B ′.
[0028]
Moreover, although the synthetic resin coil spring having a single winding structure and the manufacturing method thereof have been described in the above embodiments, even a synthetic resin coil spring having a double winding structure can be manufactured by the same method. That is, in the synthetic resin coil spring manufacturing apparatus, a pair of cutters may be disposed on both side portions on the diameter line of the rotary cutter base 5 so as to be able to advance and retract. If comprised in this way, the synthetic resin tube 4 extruded from the extrusion molding machine 1 by these cutters will be cut into a double-wound coiled filament, and these double windings will be made by retracting these cutters. A continuous cylindrical body portion can be provided on the coiled filament, and after cooling, the central portion in the longitudinal direction of the cylindrical body portion is divided into two parts to divide the double-wound coil spring portion by the coiled filament. A synthetic resin coil spring in which short cylindrical seats are integrally provided at both ends can be obtained.
[0029]
【The invention's effect】
Method for producing a synthetic resin coil spring of the present invention, as described above, as described in claim 1, a cutter at the exit of the die exit pressing the synthetic resin tube which is extruded from the extruder molder above A process of continuously cutting into a coiled wire having a predetermined length by rotating around a synthetic resin tube, and after forming the coiled wire, the cutter is moved backward to leave the synthetic resin tube as it is. A step of forming a cylindrical portion having a predetermined length connected to the coiled wire by extrusion from the extruder, and after forming the cylindrical portion, the cutter is advanced again to be extruded from the extruder. Since the process of continuously cutting and forming a synthetic resin tube into a coiled wire having a predetermined length is repeatedly performed, a synthetic resin coil having a cylindrical body part having the same diameter as the coil spring part at both ends. The spring can be manufactured easily and efficiently. In addition, the length of the coiled wire and the length of the cylindrical portion are the extrusion speed of the synthetic resin tube from the extruder and the length of the cutting time by the cutter. Can be easily set to a desired length.
[0030]
Further, after cooling while continuously forming a coiled filament and a cylindrical portion of a certain length alternately in this way, the cylindrical portion is sequentially cut at an intermediate portion in the length direction so that a short tube is formed at both ends. Since a coil spring of a certain length is provided sequentially with a cylindrical seat portion, a synthetic resin coil of a constant diameter and a constant length is provided with a short cylindrical seat portion integrally at both ends. The spring can be mass-produced efficiently.
[0031]
Further, in such a method of manufacturing a synthetic resin coil spring, the invention according to claim 2 is a composition in which a pair of cutters are arranged on both sides of the die outlet of the extruder and are extruded from the extruder. Since the resin tube is cut into a coil spring portion composed of a double-wound coiled wire, both ends of the double-winding coil spring portion are opposed to the short cylindrical seat portion. Synthetic resin coil springs can be efficiently manufactured with a 180 ° phase difference on both sides of the surface diameter line, and a more stable mounting and spring action can be provided. To get.
[Brief description of the drawings]
FIG. 1 is a front view of a coil spring made of synthetic resin.
FIG. 2 is a perspective view thereof.
FIG. 3 is a simplified longitudinal front view of an apparatus for continuously producing coil springs,
FIG. 4 is a front view showing a part of a continuous coil spring to be manufactured.
[Explanation of symbols]
A Synthetic resin coil spring 1 Extruder 3 Die 4 Synthetic resin tube
4A coiled wire
4A 'coil spring
4B cylinder
4B 'Short cylindrical seat 5 Rotating cutter base 6 Cutter 7 Retracting mechanism
13 Cooling water tank

Claims (2)

  The synthetic resin tube extruded from the extruder is continuously cut into a coiled wire having a predetermined length by rotating a cutter around the synthetic resin tube at the die outlet of the extruder. And after the formation of the coiled filament, the cutter is moved backward to extrude the synthetic resin tube as it is from the extruder to form a cylindrical portion having a predetermined length connected to the coiled filament. And a step of continuously cutting the synthetic resin tube extruded from the extrusion molding machine into a predetermined length of a coiled filament after the formation of the cylindrical portion again. In addition, after cooling the coiled filaments and the cylindrical body portions that are alternately connected to each other, the cylindrical body portions are sequentially divided at the middle portion in the length direction so that the short cylindrical seat portions are integrally provided at both ends. Carp of a certain length Sequentially to the coil spring portion consisting of Jo streak method for producing a synthetic resin coil spring and forming. A pair of cutters are arranged on both sides of the die outlet of the extrusion molding machine, and the synthetic resin tube extruded from the extrusion molding machine is cut into a coil spring portion composed of a double-wound coiled filament. The method for producing a synthetic resin coil spring according to claim 1 .

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