JPH08108238A - Swing cutting type wire rod cutting device of coiling machine - Google Patents

Abstract

PURPOSE: To select the most appropriate locus of a blade so as to always obtain clean cutting face by arbitrarily set the cutting tool arranged facing to a mandrel to the locus of a wedge shape blade by means of the action two cans for straight advancing and oscillating. CONSTITUTION: A straight advancing cam 23 and an oscillating cam 24 are turned, an oscillating base 13 is oscillated by the action of an oscillating cam 24 only around an oscillating center shaft 14 clockwise, the wedge shape blade 9a of cutting tool 9 reaches the final position. A coil spring is detached from the cut part as torn off, a broken face, which each chamfer plastic deformed by the wedge shape blade 7a of mandrel 7 and a wedge shape blade 9a of cutting tool 9 is separated by fracture extended, is formed at the cut part. By this method, no burr protruding from the outer/inner peripheries of coil and no sharp part of broken face are formed to the cut face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire rod cutting device for cutting a coil spring formed into a desired number of turns by a forming tool of a coiling machine by a cooperation of a cutting tool and a core metal to separate it from a wire rod. .

[0002]

2. Description of the Related Art Conventionally, a wire rod cutting device of a coiling machine has a D-type cutting device as shown in an enlarged view of a coil cutting portion of FIG.
Lower the cutting tool 99 from above the V-shaped cored bar 97,
A straight line cutting in which the coil spring S is cut by the upper cutting edge of the cored bar 97 and the lower cutting edge of the cutting tool 99 to separate it from the wire W is common. However, the core metal 97 and the cutting tool 99
Need to form a predetermined gap δ to prevent them from coming into contact with each other.

For this reason, for example, the "Handbook of Mechanical Engineering (New Edition)" issued by the Japan Society of Mechanical Engineers on April 15, 1987, Volume B2, Processing Science / Processing Equipment, page 106 As is well known in Chapter 4, Plastic Working, Section 4, 2.5, and Shearing, the cutting portion of the wire W is cut by the lowering of the cutting tool 99 so that the core metal 97 and the cutting tool 99 are cut.
When the cutting edge of the cutting tool bites into the wire W, the cutting tool 99 is further lowered, and the cutting edge of each cutting blade advances, as shown in FIG.
As shown in (b), "crack Cr" occurs near the tip of each blade.

When the cutting tool 99 is subsequently lowered, the cutting portions are broken and separated, but the cut surfaces of the respective cutting portions are cut by the cutting edge of the core metal 97 and the cutting tool 99 as shown in FIG. 5 (c). "Who Tr" caused by being pulled in by the blade
A “shear surface Sf” due to plastic deformation that is burnt in contact with the cutting edge, a “fracture surface Bf” separated by the “crack Cr”, and a “burr Bu” protruding from the inner and outer circumferences of the coil generated at the corner. Is formed. The size of the “burr Bu” protruding from the inner and outer circumferences of the coil changes depending on the value of the gap δ, but does not disappear as long as the gap δ exists.

When the coil spring having such a "burr Bu" on the cut surface is assembled to an electric device or the like made of, for example, a thermoplastic resin, the component parts are flawed and cause defects. Further, when a coil spring having a "burr Bu" is assembled to a device made of metal or the like, the "burr Bu" causes a deviation from a predetermined assembly position of the coil spring, and a predetermined spring characteristic cannot be obtained. There were drawbacks such as.

Rotational cutting shown in FIG. 6 is a technique developed as a wire rod cutting method in which such "burr Bu" does not appear.
This rotary cutting is performed by the wedge-shaped cutting edge 109a of the cutting tool 109.
By moving the cutting tool 109 in a descending direction, the wedge-shaped cutting edge 107a of the core metal 107 and the wedge-shaped cutting edge 109a of the cutting tool 109 bite into the wire W and move up and down by V. A “chamfer Ch” that is plastically deformed into a letter shape is formed, and as the biting progresses, a “crack Cr” occurs near the tip of the cutting edge as shown in FIG. 6B.

Subsequently, the cutting tool 109 is moved in a descending direction in an oblique direction away from the core bar to cut the coil spring S so as to tear it from the wire as shown in FIG. 6 (c). According to this rotary cutting, the wedge-shaped cutting edges 107a, 109a
By forming V-shaped “chamfered Ch” on the top and bottom of the wire W, it is possible to prevent the occurrence of “burr Bu”, but there is a disadvantage that the circular movement narrows the space at the coil forming position. By making the motion an elliptical motion, a large space for the coil forming position can be provided.

As a spring winding machine equipped with a wire rod cutting device for selectively performing such rotary cutting and the above-described straight line cutting, there is a technique known in Japanese Patent Laid-Open No. 4-284934. As shown in FIG. 7, a wire rod cutting device for rotationally cutting a spring winding machine includes a rocking table 112 that can rock about a rocking center shaft 111.
The tool holder 113 is provided so as to be linearly movable, and the upper end portion of the tool holder 113 and the crank pin portion 114a of the crank 114 are connected to the connecting rod members 115, 115, 115.
And the tool holder 11 is rotated by rotating the crank 114.
3 is moved up and down, and at the same time, the rocking base 112 is swung by the cam 116 fitted to the shaft portion of the crank 114 via the lever 117, so that the cutting blade portion of the cutting tool 118 is vertically elliptic. It is what makes me.

[0009]

A wire rod cutting device, which is known in Japanese Patent Laid-Open No. 4-284934 described in the prior art and which performs rotary cutting by elliptical motion, has a "chamfering Ch" as shown in FIG. 6 (d). The "fracture surface Bf" following "becomes slanted, and a" pointed portion b "similar to a" burr "is likely to be formed. This "pointed part b"
Is different depending on the material and the wire diameter of the wire W, and in particular, the higher the viscosity and the smaller the wire diameter, the greater the tendency for the wire cross-sectional area to become larger, which impairs the quality of the coil spring and, in the worst case, is a defective product. I have a problem.

In order to make this "pointed portion b" as small as possible, the amount of V-shaped chamfering (biting) plastically processed by a wedge-shaped cutting edge is adjusted optimally, and the "crack Cr" is broken to tear it. Although it is necessary to separate the wires, particularly in the case of a wire material having a small wire diameter, it is difficult to finely adjust the chamfering amount by rotational cutting by elliptic motion, and thus there is a problem that the "pointed portion b" is easily formed.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to freely combine the linear motion and the oscillating motion by two cams. In addition to conventional straight line cutting and rotary cutting, it is possible to set the movement locus of the cutting blade of the cutting tool most suitable for the material and wire diameter of the substantially triangular iso-wire material, as a structure with a small wire diameter and high viscosity. Even in the case of difficult-to-handle wire rods, the "burred Bu" shown in FIG.
It is an object of the present invention to provide a swing type wire rod cutting device which can obtain a clean cutting surface without the "pointed portion b" shown in (b) and further does not narrow the space at the coil forming position.

[0012]

In order to achieve the above object, a swing-cut type wire rod cutting device for a coiling machine according to the present invention uses a coil spring formed into a desired number of turns by a forming tool of the coiling machine as a core metal. In a wire rod cutting device that cuts with a cutting tool and separates it from the wire rod, a wedge-shaped cutting edge is formed at the upper end and a core metal attached to the front plate so as to project into the coil spring at the forming position, and a wedge-shaped end at the lower end. A cutting tool having a cutting edge formed thereon to cut a wire rod in cooperation with the core bar, a swing table supported by the front plate so as to be swingable in parallel with the surface of the front plate, and Two cams for rectilinear movement and swinging, which are detachably attached to the tip of a rotary shaft pivotally attached so as to penetrate the front plate at a position distant from the core metal, and the core on the swing table. It is provided so that it can move in a straight line toward the gold A slide in which a cutting tool is removably attached and a rear end of which is pivotally supported by a first cam follower that abuts against the straight-moving cam, and one end of which is fixed to the swing table and the other end of which is the swing cam. An arm to which a second cam follower is abutted, a means for driving the rotary shaft, a first spring for biasing the first cam follower to abut the straight cam, and a second cam follower. A second spring that urges the swinging cam so as to come into contact with the swinging cam is provided, and the movement locus of the wedge-shaped cutting edge of the cutting tool can be arbitrarily set by the shapes of the two cams.

The two cams, one for straight movement and the other for swinging, are attached to the rotary shaft so that their phases can be changed.

[0014]

The operation of the present invention constructed as described above will be described. By rotating the straight-moving cam and the swing-moving cam that share the rotation axis, the slide moves straight and the swing table that slidably supports the slide swings, and is attached to the slide tip. The moving locus of the wedge-shaped cutting edge of the cutting tool can be set arbitrarily.For example, the wedge-shaped cutting edge of the cutting tool vertically descends from the upper end position due to the cam shape of only the straight-moving cam, and the wedge-shaped cutting edge of the core metal. And the wedge-shaped cutting edge of the cutting tool bite into the wire to form a V-shaped plastically deformed "chamfer", and also generate a "crack" in the direction in which both cutting edges face each other, and then the swing cam. By the action of the only cam shape,
It is also possible to move the wedge-shaped cutting edge of the cutting tool laterally so that a "crack" grows and breaks, and to perform a wire rod cutting operation that separates the coil spring from the wire rod. It is possible to arbitrarily select the movement locus of the cutting blade of the cutting tool that is most suitable for difficult-to-cut materials that easily have "pointed portions".

Further, the mounting holes for the straight-moving cam and the swinging cam, which are attached to the rotary shaft, can be changed by, for example, arc-shaped elongated holes, and the wedge-shaped cutting of the cutting tool can be performed by changing the respective phases. Fine adjustment of the moving path of the blade is facilitated and setup time is reduced.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 are views showing a configuration of forming a right-handed coil spring and cutting a wire rod. When forming a left-handed coil spring and cutting a wire rod, the constituent elements that act for forming and cutting the wire rod are described in FIG. The line guide 4 is arranged symmetrically with respect to the horizontal axis.

FIG. 1 is a front view showing the entire structure of the coiling machine. A wire guide 4 for inserting and guiding a wire W is horizontally attached to the front surface of a front plate 2 erected on a machine base 1. In addition, a plurality of feed rollers 5 that sandwich the wire W and feed it forward (right side) are provided behind the line guide 4 (left side). Further, in front of the wire guide 4, forming tools 6F and 6S for forming the wire W into a coil C having a predetermined curvature and a pitch tool 8 for pressing the coil C in the forming direction to form a predetermined pitch are formed at a forming position 10. The coils C are attached so as to be able to move forward and backward.

The cored bar 7 is attached to the front plate 2 so as to project into the coil C at the molding position 10, has a substantially semicircular cross section, and has a wedge-shaped cutting edge 7a shown in FIG. Has been done. Cutting tool 9 for cutting the wire W in cooperation with the core metal 7
2 has a wedge-shaped cutting edge 9a shown in FIG. 2 (a) formed at the lower end thereof, and at the upper position facing the wedge-shaped cutting edge 7a of the core metal 7,
It is detachably attached to the slide 12 of the wire rod cutting device 11.

A swing base 13 that slidably supports the slide 12 in the vertical direction is swingably supported by the front plate 2 by a swing center shaft 14, and the slide 12 has an elongated mounting hole at its upper end. A roller base 16 formed on 16a is attached by bolts 17 so that the position can be adjusted vertically. Roller stand 1
A first cam follower 15 is pivotally supported by 6, and an adjusting screw 18 is screwed vertically downward to the lower end of the adjusting cam 1.
The lower end of 8 is brought into contact with the end surface 12a of the step portion of the slide 12, and the vertical position of the roller base 16 with respect to the slide 12 is changed, whereby the vertical position of the cutting tool 9 is adjusted.

Further, a bearing housing 21 is attached through the front plate 2 at a position above the swing base 13 of the front plate 2,
A rotary shaft 22 is pivotally supported by a plurality of bearings in a bearing housing 21, and a straight cam 23 is attached to a tip flange portion of the rotary shaft 22 and two plate cams of a swing cam 24 are detachably attached to the straight cam 23. It is worn. The swing cam 24 is screwed to the rectilinear cam 23 with a bolt 25, and the rectilinear cam 24
Are bolted to the end face of the flange portion of the rotary shaft 22 by bolts 26, and each bolt hole formed in the straight-moving cam 23 is formed in an arc-shaped elongated hole not shown centering on the rotary shaft center. Thus, the rectilinear cam 23 and the swing cam 2
It is possible to change the phase of the No. 4 rotary shaft 22 and the phase of the cams.

The slide 12 is biased upward by two springs 19 and 19, and the first cam follower 15 is constantly in pressure contact with the cam surface of the rectilinear cam 23. Furthermore, one end of the arm 27 is attached to the right shoulder of the swing table 13,
A second cam follower 28 is pivotally supported at the other end of the arm 27, and the arm 27 is supported by a spring 31 stretched in a spring box 29 fixed to the front plate 2 via a pusher 32 as shown in FIG.
The second cam follower 28 is constantly pressed against the cam surface of the swing cam 24.

A motor 33 for driving the rotary shaft 22
Is attached to a rear plate (not shown), and the gear 34 fitted to the output shaft 33a of the motor 33 is meshed with the gear 35 fitted to the rear end of the rotary shaft 22. Is rotated by a motor 33 in association with a coil forming mechanism of a coil spring, one rotation per cycle.
Further, the swing table 13 is provided with bolt holes 13a for fixing it substantially vertically to the front plate 2 by three mounting bolts (not shown), and when the swing table 13 is fixed to the front plate 2, The swinging cam 24 can be removed, and only the linear movement of the slide 12 can be used as the pitch tool device for forming the left-handed coil spring.

Next, the operation of the present embodiment constructed as described above will be described with reference to the wire rod cutting operation diagrams of FIGS. 3 (a) and 4 (a) are views showing the state before cutting the wire rod, in which the rotation of the rotary shaft 22 causes the rectilinear cam 23 and the swing cam 24 to stop at a position where they have reached a predetermined standby position, and the wire is cut. The tool 9 stands by at an upper position 9u facing the cored bar 7.

Then, the coil forming progresses to reach a predetermined length, the motor 33 is rotated by a signal that the feeding of the wire W is stopped, the rotary shaft 22, the linear cam 23, and the swing cam 24 are rotated, and the linear cam 23. The cutting tool 9 descends together with the slide 12 by the action of the chisel, and the wedge-shaped cutting blade 9a of the cutting tool 9 comes into contact with the cutting portion of the wire W and then further descends to the upper end position 9
The position 9 m at the initial stage of cutting is reached from u, and the position shown in FIG.
The state shown in FIG.

In this state, the wedge-shaped cutting edge 7a of the core metal 7 and the wedge-shaped cutting edge 9a of the cutting tool 9 bite into the wire W from above and below, and are plastically deformed into a V shape to form "chamfer Ch". A "crack Cr" occurs in the direction in which the wedge-shaped cutting edge 7a of the core metal 7 and the wedge-shaped cutting edge 9a of the cutting tool 9 face each other.

Subsequently, the rectilinear cam 23 and the swing cam 24 are rotated, and the swing base 13 swings clockwise around the swing center shaft 14 by the action of only the swing cam 24, and the cutting tool 9
The wedge-shaped cutting edge 9a of the blade is moved from the initial position 9m to the final position 9d.
To reach the state shown in FIGS. 3 (c) and 4 (c). In this state, the coil spring S is separated so as to be torn from the cut portion of the coil C, and the cut portion has a wedge-shaped cutting edge 7a of the core metal 7 and a wedge-shaped cutting of the cutting tool 9 as shown in FIG. 4 (d). Each of the “chamfering C” plastically deformed by the blade 9a
"Fracture surface Bf" where "h" and "crack Cr" are extended and separated
And are formed. Therefore, no "burr" or "pointed portion" is formed in the "broken surface Bf" protruding from the inner and outer circumferences of the coil at the cut portion.

When the wedge-shaped cutting blade 9a has a substantially right-angled triangular shape as described above, it is better to make the "chamfer Ch" relatively large in order to cause cracks.
As the wire diameter increases, the load applied to the cutting tool 9 increases, but fortunately, if the wire diameter of the wire W is large, the "pointed portion" of the fracture surface may be flawed in other components when it is assembled to an electric device or the like. However, it is unlikely to be a cause of misalignment.

Therefore, for the coil spring S having a large wire diameter, an angle θ formed by a straight line between the upper end position 9u and the initial cutting position 9m and a pseudo straight line between the initial cutting position 9m and the final cutting position 9d.
Is 90 ° or more, the depth of the “chamfer Ch” can be made relatively small. In this case, the straight cam 23
It is possible only by changing the cam shape of.

By changing the cam shapes of the straight-moving cam 23 and the swinging cam 24 to eccentric cams, it is possible to change the locus of the wedge-shaped cutting blade 9a provided on the cutting tool 9 into an ellipse, which is suitable for conventional rotary cutting. Can also handle. Also, by changing the swing cam 24 to a simple concentric disc, it is possible to cut straight lines.
In this case, slide 1 by changing the diameter of the disc.
It is possible to change the moving direction of 2 vertically or diagonally.

Straight line cutting is also possible by removing the swing cam 24 or the arm 27 and bolting the swing base 13 to the front plate 2.

[0031]

Since the present invention is configured as described above, it has the following effects. Since the cutting tool, which is arranged facing the core metal, can set the trajectory of the wedge-shaped cutting edge formed on the cutting tool by the action of the two cams for straight movement and swing, "Back" and "points"
It is possible to select the locus of the cutting edge that is most suitable for a wire rod that is easily formed, and a clean cut surface is always obtained, so that the defective rate is reduced and the quality is improved. Also, since the locus of the cutting edge can be freely selected without narrowing the space of the forming position, the degree of freedom of the spring forming mechanism increases,
It leads to improvement of production efficiency.

Further, the motor for driving the two cams is interlocked with the coil forming mechanism to form a coil spring having a desired number of coil windings by the forming tool, and subsequently the coil spring is automatically automatically formed by the core metal and the cutting tool. Since the wire is separated from the wire, automation can be facilitated, and labor saving and efficiency improvement can be achieved.

Further, since the two cams can be attached to the rotary shaft so that the respective phases can be changed, the fine adjustment in the initial setting of the locus of the cutting edge of the cutting tool is facilitated and the setup time is reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an entire coiling machine in which a swing cut type wire rod cutting position of an embodiment according to the present invention is assembled.

FIG. 2 is a configuration diagram of a swing cut type wire rod cutting device of the present embodiment, showing a state before the wire rod is cut, (a) is a front view,
(B) is a sectional view taken along the line AA of (a).

3A and 3B are explanatory views of the operation of the swing cut type cutting apparatus of the present embodiment, where FIG. 3A is a state before cutting, FIG. 3B is an initial state of cutting, and FIG. .

FIG. 4 is an enlarged explanatory view of the wire cutting portion of the operation of the present embodiment,
(A) is a state before disconnection, (b) is an initial state of disconnection,
(C) shows the state after cutting, respectively, (d) is a figure showing the shape of the cut surface of a wire rod cutting local part.

5A and 5B are enlarged explanatory views of a wire rod cutting portion of an action by a straight line cutting of a conventional technique, FIG. 5A shows a configuration of a core bar and a cutting tool after the wire rod is cut, and FIG. 5B is an initial cutting of the wire rod cutting local portion. And (c) is a diagram showing a state after cutting the wire cutting local portion.

FIG. 6 is an enlarged explanatory view of a wire rod cutting portion of the operation by the conventional rotary cutting, (a) shows a state before cutting, (b)
FIG. 4A is a diagram showing a state at an initial stage of cutting, FIG. 8C is a diagram showing a state after cutting, and FIG.

FIG. 7 is a front view of a wire cutting device of a conventional spring winding machine.

[Explanation of symbols]

 7 core metal 7a, 9a wedge-shaped cutting blade 9 cutting tool 10 forming position 11 wire rod cutting device 12 slide 13 swinging table 14 swing center shaft 15 first cam follower 19,31 spring 22 rotary shaft 23 rectilinear cam 24 swing cam 28 28th 2 Cam follower 33 Motor Bf Fracture surface C Coil Ch Chamfer Cr Crack S Coil spring Sf Shear surface W Wire rod

Claims (2)

[Claims] 1. A wire rod cutting device for cutting a coil spring formed into a desired number of turns by a forming tool of a coiling machine with a core metal and a cutting tool to separate the coil spring from a wire rod.
A core metal attached to the front plate so that a wedge-shaped cutting edge is formed at the upper end and protrudes into the coil spring at the forming position, and a wedge-shaped cutting edge is formed at the lower end to cut the wire rod in cooperation with the core metal. A cutting tool, a swing table supported by the front plate so as to be swingable parallel to the surface of the front plate, and a front plate at a position away from the swing table on the side opposite to the core bar. Two cams for rectilinear movement and swinging, which are detachably attached to the tip of the rotating shaft to be pivotally attached, and linearly movable toward the core metal on the swing base, and the cutting is provided at the tip. A slide to which a tool is detachably attached and a first cam follower that abuts against the straight-moving cam is pivotally supported at a rear end, and one end is fixed to the swing base and the swing cam is abutted at the other end. An arm to which a contacting second cam follower is pivotally attached, and means for driving the rotating shaft,
A first spring for urging the first cam follower to come into contact with the straight-moving cam, and a second spring for urging the second cam follower to come into contact with the swing cam. Swing-cut type wire rod cutting device for a coiling machine, characterized in that the movement locus of the wedge-shaped cutting edge of the cutting tool can be set arbitrarily by the shape of the cam. 2. A cam for straight movement and a cam for swinging are attached to a rotary shaft so that the respective phases can be changed.
Swing-cut type wire rod cutting device for the coiling machine described.