JPH0147265B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot coil spring manufacturing apparatus.

Conventionally, devices for manufacturing coil springs by hot forming have been equipped with a freely rotatable lead screw with a spiral groove around its outer periphery adjacent to a core metal that rotates at a constant speed. The tip of the wire is fixed to the core metal through the lead screw, and by holding the wire with the lead screw and rotating the core metal, the wire is fed along the spiral groove and spiraled around the outer circumference of the core metal. Something that can be wrapped around the shape is used,
In such a device, the strands are heated and become soft as they are guided by the lead screw.
There was a problem in which the wires were scratched due to the strong rubbing of the spiral grooves, especially the sharp edges.

The present invention was completed in view of the above circumstances, and is a novel device that does not use lead screws in order to avoid damaging the wires when manufacturing coil springs by hot forming. The purpose is to provide

Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

Reference numeral 1 denotes a core metal which is rotatably supported for winding the strand a, and a drive shaft 2 fixed to one end of this core metal 1 is connected to a first motor 3, and one end side of the drive shaft 2 is fixed to one end of the core metal 1. A material clamp 4 for fixing the starting end of the strand a is attached to the outer periphery of the core bar 1, and a presser roller 5 is mounted on the upper surface of the core bar 1 so as to be movable up and down.

A guide bar 7 and a first feed screw 8 are installed on the side of the core metal 1 at intervals parallel to the axial direction of the core metal 1, and the guide bar 7 is inserted between the bearings 9, 9. The first feed screw 8 is rotatably supported by bearings 10, 10, and one end thereof is connected to the second motor 11. An elongated rectangular cylindrical moving body 6 is installed on the upper surface of the screw 8 so as to face in a direction perpendicular to the axial direction of the core metal 1. The protrusion 12 is slidably fitted into the guide bar 7, and the protrusion 13 on the right side is screwed onto the first feed screw 8.

Inside this movable body 6, there is a second
A feed screw 15 is inserted into the movable body 6, and is rotatably supported by bearings 16 fitted to both ends of the movable body 6, one end of which is connected to the third motor 20. A locking body 21 is attached to the locking body 6 so as to be able to freely slide in the axial direction along a guide groove 22 formed on the upper surface thereof, and the lower end of this locking body 21 is attached to the second feed screw 15 described above. The portion that is screwed together and protrudes from the top surface of the movable body 6 is adapted to fix the terminal end of the strand a.

Further, a torque meter 23 for measuring the torque is connected to the drive shaft 2 of the core metal 1, and a signal for controlling the rotational speed of the third motor 20 is sent to the torque meter 23. A motor drive control circuit 24 is connected, and when the torque of the drive shaft 2 is larger than a predetermined value, the rotation speed of the third motor 20 increases, and conversely, when the torque is small, the rotation speed increases. It's getting late.

Next, the operation of this embodiment will be explained.

First, as shown by the solid line in FIG. 1, the movable body 6 is moved to a position corresponding to the winding start end of the core bar 1, and the locking body 21 is moved to the third motor 20 side, and
With the presser roller 5 retracted to the upper position as shown by the chain line in FIG.
The starting end is fixed to the material grip 4 of the core bar 1, and the terminal end is fixed to the locking body 21.

Then, the first motor 3 is started to rotate the core bar 1 counterclockwise in FIG. 2 at a constant rotation speed, and the second motor 11 is started to rotate the moving body 6
is moved toward the winding end of the core bar 1 at a constant moving speed depending on the pitch of the coil spring to be manufactured, and at the same time, the third motor 20 is started to move the locking body 21 to the core. It moves toward the core metal 1 at a speed corresponding to the rotation speed of the metal 1.

Throughout this winding process, as the tension of the wire a increases, the torque of the drive shaft 2 increases, so the rotation speed of the third motor 20 is increased by the control signal from the motor drive control circuit 24. , as the locking body 21 moves quickly, the force that pulls the wire a becomes weaker, and the tension becomes smaller.
Conversely, when the tension of the strand a decreases, the torque of the drive shaft 2 decreases, so the rotational speed of the third motor 20 is lowered, and the moving speed of the locking body 21 is slowed down. When a is pulled, the tension increases, and the tension of the strand a is automatically maintained at a constant value.

Then, as shown by the chain line in FIG.
When the end of the wire a reaches the position corresponding to the winding end of the core metal 1, the end of the strand a is released from the locking body 21, and the presser roller 5
is lowered, and the strand a is pressed between the core bar 1 and the presser roller 5 to form a coil spring.

Next, another embodiment of the device for controlling the moving speed of the locking body 21 is shown. When a tensile load is applied to the locking body 21, the second feed screw 15 screwed therewith is pulled The tensile stress of the second feed screw 15 increases or decreases depending on the magnitude of the tension of the strand a, so by keeping this tensile stress at a constant value, the tension of the strand a can be reduced. A strain gauge 25 for measuring tensile stress is connected to the protruding end of the second feed screw 15 on the third motor 20 side. The motor drive control circuit 24 described above is connected, and when the tensile stress of the second feed screw 15 increases, the motor drive control circuit 24
The rotational speed of the third motor 20 is increased by the control signal from the 3rd motor 20, the locking body 21 moves quickly, the tension of the strand a becomes smaller, and conversely, when the tensile stress of the second feed screw 15 becomes smaller, The rotational speed of the third motor 20 is lowered, the moving speed of the locking body 21 is reduced, and the tension of the strand a is increased.
The tension of the strand a is kept at a constant value.

In addition, as another embodiment not shown, the locking body 2
1 is provided with a braking device that applies a braking force to apply tension to the strand a, and a torque meter 23 detects fluctuations in the torque of the drive shaft 2 of the core metal 1, and this detection signal is detected by a torque meter 23. The tension of the strand a may be maintained at a constant value by controlling the braking force of the braking device according to the above.

Furthermore, the movable body 6 may be moved not by the feed screw but by other moving means such as a hydraulic cylinder.

As specifically explained in the above embodiment,
The hot coil spring manufacturing apparatus of the present invention includes a core metal that locks one end of a heated strand and is driven to rotate in one direction at a desired speed to spirally wind the strand, and the core metal. a movable body that moves in one direction parallel to the axial direction of the core metal at a desired speed corresponding to the rotational speed of the core metal; A locking body that moves in a direction perpendicular to the axial direction of the wire, and a control device that controls the moving speed of the locking body to maintain the tension of the wire at a substantially constant value. Since there is no lead screw for guiding the strands, there is no risk of damaging the strands, and the tension of the strands is maintained at a constant value. This has the effect of making it possible to manufacture coil springs with different diameters.

[Brief explanation of drawings]

1 to 3 show an embodiment of the device of the present invention, FIG. 1 is a partially cutaway plan view and block diagram, FIG. 2 is a vertical sectional view, and FIG. 3 is a partially cutaway sectional view of the main part. It is a diagram. DESCRIPTION OF SYMBOLS 1: Core metal, 2: Drive shaft, 6: Moving body, 15: Second feed screw, 20: Third motor, 21: Locking body, 23: Torque meter, 24: Motor drive control circuit, 25: Strain meter, a: bare wire.

Claims (1)

[Scope of Claims] 1. A core metal that locks one end of a heated strand and is driven to rotate in one direction at a desired speed to spirally wind the strand, and a core metal that corresponds to the rotational speed of the core metal. a moving body that moves in one direction parallel to the axial direction of the cored metal at a desired speed; A hot coil spring comprising: a locking body that moves in a perpendicular direction; and a control device that controls the moving speed of the locking body to maintain the tension of the wire at a substantially constant value. Manufacturing equipment.