JP5089197B2 - Wire rod forging machine and forging method - Google Patents

Description

  The present invention relates to a wire rod forging machine that expands the diameter of a wire rod by installing the tip of the wire rod, and a forging method thereof.

A wire forging machine and a forging method of this type are disclosed in Patent Document 1, for example. In the forging machine and the forging method of Patent Document 1, the tip of the wire is protruded by a predetermined length and gripped by a chuck, and in this state, the tip of the wire is hit by a forging punch and installed, and the outer diameter of the tip is reduced. The diameter is constantly expanded.
Japanese Patent Publication No.52-476

  In the forging machine and the forging method of Patent Document 1 described above, the installation of the wire by the forging punch is repeated for a predetermined number of wires, and after the forging machine reaches a steady operating environment, the tip of the wire is removed. Although the diameter can be expanded to the specified outer diameter, the tip of the wire cannot be expanded to the desired outer diameter before reaching the steady operating environment. Smaller than outer diameter.

Therefore, when the upsetting of the wire is repeated, the occurrence of an upsetting failure cannot be avoided in the initial stage, and a defective processed product is manufactured. This becomes conspicuous in the ambient temperature of the forging machine, that is, in winter when the room temperature is low.
The present invention has been made based on the above-mentioned circumstances, and the purpose thereof is to stably expand the tip of the wire to a prescribed outer diameter from the first wire uptake regardless of the ambient temperature. The object is to provide a wire rod forging machine and a forging method.

In order to achieve the above object, the wire rod forging machine according to the present invention is arranged in the wire transfer path, allows the wire to pass through, and can grip the wire with the tip of the wire protruding to the downstream side of the transfer route. A chuck device, and an upsetting device that is disposed downstream of the chuck device in the transfer path and installs the tip of the wire held by the chuck device with a forging punch to expand the diameter. The upsetting device includes preheating means for preheating the forging punch, and the chuck device is disposed on each side of the transfer path and has an axis extending along the transfer path, and is rotatable and transferred about the axis. A pair of chuck cylinders supported so as to be relatively close to and away from each other in the transverse direction of the path, and formed so as to face the outer peripheral surfaces of the pair of chuck cylinders with the transfer path interposed therebetween, and a wire holding path in the middle of the transfer path A pair of chuck groove to secure, a pair of chuck cylinder taken away relatively against the said transverse direction, and tightening clamping means the wire in the clamping passage in between the chuck groove when brought close pair of chuck cylinder, Rotating means for rotating the pair of chuck cylinders in opposite directions and reciprocating the pair of chuck grooves along the circumferential direction of the corresponding chuck cylinder to expand and contract the separation distance between the pair of chuck grooves. Item 1).

Preferably, the preheating means preheats the forging punch to a steady temperature at which the temperature of the forging punch reaches after the wire material is repeatedly installed a predetermined number of times.
According to the forging machine of claims 1 and 2, prior to the start of the upsetting of the wire rod, that is, prior to the operation of the forging machine, the forging punch of the upsetting apparatus is preheated by the preheating means, and reaches the above-described steady temperature. Preheated.
In this state, the tip end of the wire rod is installed by the forging punch, and the diameter is expanded as the installation end. After that, the chuck device rotates the pair of chuck cylinders in the opposite directions to each other, so that the pair of chuck grooves The distance between them is increased. As a result, the wire is pulled back along the transfer path regardless of the upset end with the enlarged diameter.

Specifically, the preheating means can include an induction heating coil that is disposed in the transfer path and can surround the forging punch (Claim 3), and the induction heating coil has the tip end of the wire at the upsetting temperature. It is preferable to use also as a heater to heat (Claim 4). In this case, the induction heating coil is used not only for preheating the forging punch but also for heating the tip of the wire rod.
Further, the present invention provides a wire rod forging method in which the tip end of the wire rod is protruded from the chuck device, the wire rod is gripped by the chuck device of claim 1, and the tip end of the wire rod is installed and expanded in this state by a forging punch. In the forging method of the present invention, the forging punch is preheated before the wire material is repeatedly set up (Claim 5).

  Specifically, as in the above-described forging machine, preheating of the forging punch is performed to a steady temperature at which the temperature of the forging punch reaches after the wire material has been repeatedly installed a predetermined number of times (claimed). Item 6).

  In the wire rod forging machine and the forging method according to claims 1 to 6, prior to the repeated installation of the wire rod, that is, prior to the operation of the forging machine, the forging punch of the upsetting device is preheated. Regardless of the ambient environmental temperature, from the first installation of the wire, the tip of the wire can be reliably expanded to a specified outer diameter, and processing defects can be effectively prevented.

If the preheating of the forging punch is performed until the steady temperature is reached, the tip of the wire rod after the upsetting can be accurately matched with a specified outer diameter.
Furthermore, if the induction heating coil for preheating the forging punch is also used for heating the tip of the wire, the forging machine has a simple configuration.

FIG. 1 schematically shows a wire rod forging machine according to an embodiment.
The forging machine includes a transfer path 2 for the wire A, and the transfer path 2 extends horizontally. Here, the wire A is made of a PC (prestressed concrete) steel rod, and has a plurality of spiral grooves (not shown) on the outer peripheral surface thereof.
An upsetting device 4 is arranged at the downstream end of the transfer path 2, and a wire A transferring device is arranged at the upstream side of the upsetting device 4. In FIG. 1, the transfer device is shown only by a pair of pinch rollers 6. These pinch rollers 6 are arranged with the transfer path 2 interposed therebetween and can be brought into contact with and separated from each other. When the wire A is reciprocally transferred along the transfer path 2 by the transfer device, the transfer is guided. That is, the wire A can be advanced and retracted with respect to the upsetting device 4.

Further, a chuck device 8 is disposed between the pair of pinch rollers 6 and the upsetting device 4, and the chuck device 8 will be described later.
The upsetting device 4 includes a cylinder block 10, which has a cylinder bore 12 that is coaxial with the transfer path 2. A plunger 14 is slidably fitted to the cylinder bore 12, and the plunger 14 protrudes from the cylinder bore 12 toward the chuck device 8. A pressing punch 16 is attached to the protruding end of the plunger 14, and the pressing punch 16 is positioned on the transfer path 2.

On the other hand, a double-acting forging cylinder 18 is connected to the cylinder bore 12, and the forging cylinder 18 has a piston rod 20 that enters the cylinder bore 12.
Further, a cylinder bore 22 parallel to the cylinder bore 12 is formed in the cylinder block 10, and a piston rod 26 of a double acting type extracting cylinder 24 is slidably fitted in the cylinder bore 22. The piston rod 26 projects from the cylinder block 10 toward the chuck device 8, and the projecting ends of the plunger 14 and the piston rod 26 are connected to each other via an arm 28.

  More specifically, although the arm 28 is fixed to the plunger 14, the piston rod 26 can move only to the right from the state shown in FIG. That is, the protruding end portion of the piston rod 26 is formed with a small-diameter portion at the tip side, and has a step surface at the boundary with the small-diameter portion. Therefore, the arm 28 is in contact with the step surface of the piston rod 26 in the state shown in the figure.

On the other hand, a spring seat 30 is provided at the tip of the piston rod 26, and a compression coil spring 32 is bridged between the spring seat 30 and the arm 28. The compression coil spring 32 presses and urges the arm 28 toward the step surface of the piston rod 26.
Further, a rack 34 is attached to the arm 28, and the rack 34 is connected to a rotary encoder 38 via a pinion 36. The rotary encoder 38 is fixed to the cylinder block 10 side.

  The forging cylinder 18 and the sizing cylinder 24 described above operate by receiving pressure oil supplied from the hydraulic circuit 40 shown in FIG. Specifically, the hydraulic circuit 40 includes a hydraulic source 42, and the hydraulic source 42 includes a motor-driven hydraulic pump 43. Electromagnetic direction switching valves 44 and 46 are disposed between the hydraulic source 42 and the pressure cylinder 18, and these electromagnetic direction switching valves 44 and 46 control supply and discharge of pressure oil to the pressure cylinder 18 by their switching operation. The piston rod 20 of the forging cylinder 18 is reciprocated.

An electromagnetic direction switching valve 48 is also disposed between the hydraulic pressure source 42 and the dimensioning cylinder 24. The electromagnetic direction switching valve 48 controls the supply and discharge of pressure oil to the dimensioning cylinder 24 by the switching operation. The piston rod 26 of the take-out cylinder 24 is reciprocated.
Further, an induction heating coil 50 is provided between the forging punch 16 and the chuck device 8 described above. The induction heating coil 50 is arranged concentrically with the transfer path 2 and is transferred as is apparent from FIG. It extends along the path 2. The induction heating coil 50 is electrically connected to a power supply (not shown) via a lead wire, and can receive power from this power supply.

When the forging punch 16 is in the induction heating coil 50 in the state shown in FIG. 1, when the induction heating coil 50 is supplied with power, the dielectric heating coil 50 is moved to the forging punch 16. In this way, the forging punch 16 is preheated.
Next, the above-described chuck device 8 will be described.
As apparent from the chuck device 8 shown in the lower part of FIG. 1, the chuck device 8 includes a pair of chuck cylinders 52 _L and 52 _R. These chuck cylinders 52 _L and 52 _R are arranged on both sides of the transfer path 2 with the transfer path 2 in between, and have axes parallel to the transfer path 2. Chuck cylinder 52 _L, 52 _R are rotatably supported on their axes around the receiving member 53 for covering these outer peripheral surface partially also with respect to the chuck cylinder 52 _L, the chuck cylinder 52 _R its receiving member 53 It is possible to contact and separate in a direction crossing the transfer path 2 via That is, in this embodiment, the chuck cylinder 52 _R is movable in the horizontal direction.

Further, when viewed from the transfer path 2, the upstream end faces of the pair of chuck cylinders 52 _L and 52 _R are supported by end plates 55, respectively. The end plates 55 are attached to the chuck device 8 depicted in the upper part of FIG. It is clearly shown.
As is clear from the chuck device 8 depicted in the lower part of FIG. 1, a chuck cylinder 54 is disposed on the side of the chuck cylinder 52 _R , and this chuck cylinder 54 is a piston 56 facing the chuck cylinder 52 _R. including. The piston 56 has a front end surface exposed toward the chuck cylinder 52 _R, the distal end surface is in contact with the receiving member 53 which forms a chucking cylinder 52 _R and set via the pressing member (not shown).

Moreover, the chuck cylinder 54 is provided with a pull rod 60, the pull rod 60 and the inner end 58 screwed into the receiving member 53 of the chuck cylinder 52 _R, projecting outwardly from the end wall forming the barrel of the chuck cylinder 54 A pull spring 62 made of a compression coil spring is bridged between the outer end and the outer cylinder. The pull spring 62 biases in a direction away of the piston 56 from the chuck cylinder 52 _R.

On the other hand, the chuck cylinder 54 is also connected to the hydraulic circuit 40 described above, and an electromagnetic direction switching valve 64 and a boost cylinder 66 are sequentially arranged between the hydraulic source 42 and the chuck cylinder 54 from the hydraulic source 42 side. The electromagnetic direction switching valve 64 controls supply / discharge of pressure oil to / from the boost cylinder 66 by the switching operation, and operates the boost cylinder 66.
When the boost cylinder 66 is operated in response to the switching operation of the electromagnetic direction switching valve 64 from the rest position to the operation position (the position shown in the drawing), the boost cylinder 66 supplies high pressure oil to the chuck cylinder 54, thereby , the piston 56 of the chuck cylinder 54 via the pressing member and the receiving member 53, presses the chuck cylinder 52 _R from its rest position to the chuck cylinder 52 _L. Therefore, the pull rod 60 connected to the receiving member 53 resists the urging force of the pull spring 62 and is moved toward the chuck cylinder 52L together with the receiving member 53 while contracting the pull spring 62.

On the other hand, when the directional control valve 64 is returned to the rest position, the pull rod 60 is pulled back by the urging force of the pull spring 62, along with this, the receiving member 53 is pulled back with a chuck cylinder 52 _R, thereby The piston 56 of the chuck cylinder 54 and the piston of the boost cylinder 66 are also returned to the rest position.
Since the chuck cylinders 52 _L and 52 _R have the same structure, the structure of the chuck cylinders 52 _L will be described below with a focus on one chuck cylinder 52 _L.

The chuck cylinders 52 _L and 52 _R have a plurality of chuck grooves on their outer peripheral surfaces, and these chuck grooves are arranged at equal intervals in the circumferential direction of the chuck cylinder 52. In FIG. 1, only one chuck groove in each of the chuck cylinders 52 _L and 52 _R is shown.
Each chuck groove of the chuck cylinder 52 has a circular arc shape in cross section and extends along the axis of the chuck cylinder 52 over the entire length, but their sizes are different from each other.

As is apparent from the chuck device 8 depicted in the lower part of FIG. 1, the chuck grooves of the chuck cylinders 52 _L and 52 _R have the same size facing each other across the transfer path 2 according to the diameter of the wire A, A clamping passage 78 for the wire A is formed between the chuck grooves, and the clamping passage 78 is arranged on the transfer path 2.
1 is in an open state, and the wire A can pass through the clamping passage 78 when the wire A is transferred along the transfer path 2. Thereafter, the chuck cylinder 54 as described above pushes the piston 56, since the axis distance between the pair of the chuck cylinder 52 _L, 52 _R is narrowed, closed clamping passage 78, a pair of chucks which form the clamping passage 78 The wire A is firmly tightened between the grooves 68.

On the other hand, the pair of chuck cylinders 52 _L and 52 _R are connected to a rotating device 80, and the rotating device 80 will be described below.
The rotating device 80 includes a discharge cylinder 82 as a drive source. The discharge cylinder 82 is disposed below the pair of chuck cylinders 52 _L and 52 _R , and has a piston rod 84 that extends upward toward the chuck cylinders 52 _L and 52 _R. A rod end 86 is attached to the upper end of the piston rod 84, and the rod end 86 is connected to the chuck cylinder 52 on the corresponding side via link arms 88 and 90 one by one on the left and right.

More specifically, the upper link arm 90 is attached to a shaft 92, and this shaft 92 is connected to the corresponding chuck cylinder 52 via a plurality of connecting bolts (not shown).
When the piston rod 84 of the discharge cylinder 82 is contracted from the state shown in the drawing, the rod end 86 is lowered, and this lowering is converted into the rotation of the corresponding chuck cylinder 52 via the pair of left and right link arms 88 and 90. The In this case, the pair of chuck cylinders 52 _L and 52 _R rotate in opposite directions so that the pair of chuck grooves forming the clamping passage 78 move upward. Therefore, these chuck grooves are separated from each other, and thereby the holding passage 78 is opened.

Thereafter, when the piston rod 84 of the discharge cylinder 82 is extended, the pair of chuck cylinders 52 _L and 52 _R are rotated in opposite directions, so that the chuck groove sandwiches the transfer path 2, and holds the clamping path 78. Form again.
In order to extend and contract the piston rod 84 of the discharge cylinder 82 described above, the discharge cylinder 82 is also connected to the hydraulic circuit 40 described above, and an electromagnetic direction switching valve 94 is disposed between the hydraulic source 42 and the discharge cylinder 82. Yes. The electromagnetic direction switching valve 94 controls supply / discharge of pressure oil to / from the discharge cylinder 82 by the switching operation, and expands / contracts the piston rod 84 of the discharge cylinder 82.

If necessary, a proximity switch 96 is disposed in the vicinity of the piston rod 84, while a detection element 98 that turns the proximity switch 96 on and off is attached to the rod end 86. These proximity switches 96 and the detector 98, if the automatic operation of the forging machine is implemented, the operation of the discharge cylinder 82, i.e., is used to detect the rotation of the chuck cylinder 52 _L, 52 _R.

Next, the forging method of the wire A performed using the forging machine described above will be described with reference to FIGS.
2 and 3, the posture of the rotating device 80 and the pair of pinch rollers 6 is shown in a state different from the actual posture for the convenience of drawing.
First, before the forging machine is operated, the forging machine performs the preheating operation shown in FIG.

  In this preheating operation, the above-described dimensioning cylinder 24 is extended, and the forging punch 16 is moved together with the plunger 14 of the setting device 4 toward the above-described induction heating coil 50 via the arm 28, and the inside of this induction heating coil 50. To the predetermined position. In this state, the induction heating coil 50 is energized from the power supply, and the induction heating coil 50 preheats the forging punch 16. The preheating temperature here is a steady temperature at which the temperature of the forging punch 16 reaches after a later-described upsetting operation shown in FIG. 3 is repeatedly performed on a predetermined number of wires A. Specifically, the steady temperature is about 400 ° C., and therefore the forging punch 16 is preheated to about 400 ° C.

When preheating of the forging punch 16 is completed, energization to the induction heating coil 50 is stopped, and the upsetting operation shown in FIG. 3 can be performed.
This upsetting operation, first, as shown in FIG. 3 (a), the line material A is transported towards the upset device 4 More transfer device, the line material A is passed through the nipping passage 78 of the chuck unit 8 Thereafter, the tip thereof is brought into contact with the tip of the forging punch 16. That is, the transfer of the wire A is stopped when the tip of the wire A comes into contact with the tip of the pressing punch 16, and at this time, the tip of the wire A protrudes from the clamping passage 78 by a certain length, and together with the pressing punch 16 It is in a state surrounded by the induction heating coil 50 described above.

  When the tip of the wire A comes into contact with the forging punch 16, the chuck cylinder 54 is operated, while the dimensioning cylinder 24 is contracted, and the induction heating coil 50 is energized again from the power supply, and the wire A Is rapidly heated to a predetermined upsetting temperature (FIG. 3B). The upsetting temperature here is about 700 ° C., and the induction heating coil 50 functions not only as the preheating of the forging punch 16 described above, but also as a heater for heating the tip of the wire A to the upsetting temperature.

The chuck cylinder 54 as described above since the push toward the chuck cylinder 52 _R in the chuck cylinder 52 _L, wires A in the clamping passages 78, clamped in between a pair of chucks grooves forming a clamping channel 78, the chuck It is firmly chucked between the cylinders 52 _L and 52 _R.
When the tip of the wire A reaches the upsetting temperature, the dimensioning cylinder 24 brings the forging punch 16 into contact with the tip of the wire A (FIG. 3c). Thereafter, the forging cylinder 18 is extended, and the plunger 14 is rapidly pushed toward the one end of the wire A together with the forging punch 16 through the piston rod 20. As a result, the forging punch 16 is struck against the tip of the wire A, so that the tip of the wire A is subjected to upsetting and formed into an upset end B having an enlarged diameter (FIG. 3D). At this time, the pressing of the forging punch 16 contracts the compression coil spring 32 of the measuring cylinder 24, and the encoder 38 pushes in after the pressing punch 16 comes into contact with the tip of the wire A, that is, the amount of upsetting. Measure.

When the installation is completed, the chuck cylinder 54 is released and the wire A is clamped by the pair of cylindrical chucks 52 _L and 52 _R. Thereafter, the forging cylinder 18 is further operated and the forging punch 16 is passed through. The set-up end B of the wire A is pushed back toward the pair of cylindrical chucks 52 _L and 52 _R (FIG. 3D). Such pushing of the upsetting end B causes the upsetting end B to escape from the induction heating coil 50.

Thereafter, as shown in FIG. 3E, the rotating device 80, that is, the discharge cylinder 82 thereof is operated, and the chuck cylinders 52 _L and 52 _R are rotated in opposite directions. Therefore, the clamping passage 78 is opened as described above, the wire A is released from the chuck cylinders 52 _L and 52 _R, and the portion of the wire A on the upset end B side is lifted above the chuck cylinder 52.
Thereafter, when the pinch roller 6 described above is operated, the wire A is pulled back along the transfer path 2 without the interference of the set-up end B of the chuck cylinders 52 _L and 52 _R (FIG. 3F). ).

Here, as shown in FIG. 3 (f), the transfer device is provided with a whisker-like detection element 152 and a limit switch 154 immediately upstream of the pair of pinch rollers 6, and the upsetting end B of the wire A Passes through the detection element 152, the detection element 152 is released from the wire A, and the limit switch 154 is turned on. In response to this ON operation, the pair of pinch rollers 6 are separated from each other so as to allow passage of the upset end B as shown in FIG. Thus, regardless of the presence of these pinch rollers 6, the wire rod A further retracted to a predetermined position, whereas, by heading cylinder 1 8 moves back, heading machine returns to the state shown in FIG. 3 (a) To do.

As apparent from FIG. 3A, when the wire A is transferred toward the chuck device 8 and passes through the pair of pinch rollers 6, the wire A comes into contact with the detection element 152 and is detected. The child 152 is separated from the limit switch 154, and the limit switch 154 is turned off.
In addition, the processed wire A is transferred from the transfer path 2 toward the subsequent stage (not shown), and then the forging machine is supplied with a new wire A, and the new wire A is described above. 3 (a) to 3 (g) are repeated.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, the specific structure of the forging machine of the present invention can be arbitrarily changed without departing from the gist of the present invention. For example, the preheating of the forging punch 16 and the heating of the tip portion of the wire A may be performed by an induction heating coil arranged separately. Further, the wire is not limited to the PC steel rod.

It is a figure which shows schematically the forging machine of one Example. It is a figure for demonstrating the preheating operation | movement of a forging punch. It is the figure which showed the upsetting operation | movement with respect to the front-end | tip part of the wire A in the order of (a)-(g).

Explanation of symbols

2 Transfer path 4 Upsetting device 8 Chuck device 16 Forging punch 50 Induction heating coil (preheating means)

Claims (6)

A chuck device that is disposed in a wire transfer path, allows the wire to pass therethrough, and can grip the wire in a state where a tip of the wire protrudes downstream of the transfer path;
An upsetting device that is disposed downstream of the chuck device in the transfer path, and that installs the tip of the wire held by the chuck device with a forging punch to expand the diameter;
The upsetting device includes preheating means for preheating the forging punch,
The chuck device includes:
A pair of chuck cylinders disposed on both sides of the transfer path, having an axis extending along the transfer path, supported so as to be rotatable about the axis and relatively movable in the transverse direction of the transfer path. When,
A pair of chuck grooves formed on the outer peripheral surfaces of the pair of chuck cylinders so as to face each other with the transfer path interposed therebetween, and securing a holding path for the wire rod in the middle of the transfer path;
Wherein the pair of chuck cylinder taken away relatively against the said transverse direction, and fastening means Tighten the wire in the clamping passage in between the chuck grooves when the pair of chuck cylinder is close,
Rotating means for rotating the pair of chuck cylinders in directions opposite to each other and reciprocating the pair of chuck grooves along the circumferential direction of the corresponding chuck cylinder to expand or contract the separation distance between the pair of chuck grooves. A wire rod forging machine characterized by including.   2. The wire rod forging machine according to claim 1, wherein the preheating unit preheats the forging punch to a steady temperature at which the temperature of the forging punch reaches after the wire rod is repeatedly installed a predetermined number of times. .   3. The wire rod forging machine according to claim 1, wherein the preheating means includes an induction heating coil that is disposed in the transfer path and can surround the forging punch. 4.   4. The wire forging machine according to claim 3, wherein the induction heating coil also serves as a heater for heating the tip of the wire to an upsetting temperature. In the forging method of the wire rod, the tip end of the wire rod is protruded from the chuck device, the wire rod is gripped by the chuck device of claim 1, and in this state, the tip end of the wire rod is installed by a forging punch to expand the diameter.
A method for forging a wire, wherein the forging punch is preheated before the wire is repeatedly installed.   6. The method of forging a wire according to claim 5, wherein the preheating of the forging punch is performed to a steady temperature at which the temperature of the forging punch reaches after the wire has been repeatedly installed a predetermined number of times.

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