JP2726637B2 - Gas pressure welding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas pressure welding apparatus for joining a pair of metal bars in the axial direction by gas pressure welding.

[0002]

2. Description of the Related Art For example, a reinforcing bar arranged in a predetermined shape when reinforced concrete is constructed has a fixed length that is easy to handle in manufacturing or transportation. Therefore, when the length of the reinforced concrete to be constructed is equal to or longer than the entire length of the reinforcing bar, the reinforcing bar is connected in the axial direction and is used after being extended to a required length. There are various methods for connecting the reinforcing bars. There are lap joints for overlapping and fixing a part of two reinforcing bars, a sleeve joint for connecting a steel sleeve over a butt portion of the reinforcing bars, and an end surface of the reinforcing bar as an axis. Gas pressure welding in which heating is performed by gas or the like while pressing each other in the center direction with a predetermined force, or holding the end faces of the reinforcing bars at a predetermined distance from each other, heating and pouring a welding material between the end faces.
Although B welding and the like are used, gas pressure welding or CB welding or the like is preferable in terms of strength and reliability, and gas pressure welding is often used in terms of workability.

[0003] The above gas pressure welding is performed, for example, by a rod holding device for holding a pair of metal rods such as rebars in a state where their axial centers coincide with each other and their end faces are butted against each other. This is performed by a gas pressure contact device including a pressurizing device that presses a pair of rebars held by a material holding device in a direction of pressing each other, and a heating torch that heats the vicinity of the end surfaces of the pair of rebars from the outer peripheral side. .

[0004]

By the way, the gas pressure welding operation of the rebar using the gas pressure welding device has been conventionally performed as follows. First, as described above, a pair of rebars is held and pressurized to a predetermined pressing force, and primary heating is performed by heating the end faces from the outer peripheral side with a heating torch.
Then, after the end face softened by heating starts to expand in the radial direction (that is, after the end face is softened to an extent suitable for joining), heating is continued while reciprocating the heating torch in the axial direction of the reinforcing bar. As a result, secondary heating (width grilling) for heating the entire area between two positions separated by a predetermined distance from the end face to both sides in the axial direction is performed. At this time, the pressing force in the axial direction gradually decreases with the softening of the reinforcing bar. Then, after the pressing force is reduced to a predetermined pressure, the pressure is again applied by a pressurizing device and tertiary heating for heating the bulging portion is performed, and heating is performed after the bulging portion near the joining end surface has a predetermined size. Is stopped, the pair of reinforcing bars are joined.

[0005] However, in the conventional pressure welding method described above,
As described above, the primary to tertiary heating steps are required, so that the joining takes time, and in the secondary heating (width grilling), the work is complicated because the heating torch needs to be reciprocated, and therefore, There has been a problem that the joining conditions are likely to vary, and the reliability of the joining strength of the reinforcing bar cannot be sufficiently obtained. That is, in gas pressure welding, by heating and pressurizing, diffusion of atoms occurs between the end faces of the pair of reinforcing bars, so that both reinforcing bars are integrated,
Although high bonding strength can be obtained, when bonding conditions (pressure and temperature) are not appropriate, gaps are formed at the bonding interface and diffusion of atoms does not proceed sufficiently, or inclusions that hinder bonding are formed. Is deposited on the end face from inside the reinforcing bar, and both reinforcing bars cannot be integrated at the atomic level. Therefore, such a joint portion of the reinforcing bar is broken by a relatively low strength by pulling or bending, and the broken surface has a special smooth broken surface called a flat broken surface caused by the gap or inclusion (that is, a broken surface). The fracture surface is not a crystal fracture surface).

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to be able to join metal rods such as rebars in a short time and to have high reliability of joining strength. An object of the present invention is to provide an obtained gas pressure welding device.

[0007]

In order to achieve the above object, the gist of the present invention is a gas pressure welding apparatus as described above, wherein the heating torch comprises: A plurality of craters for a press-contact surface forming a frame (flame) directed to the end face for heating from the side, and (b) heating from the outer peripheral side a position separated from the end face by a predetermined distance on both sides in the axial direction. A plurality of width-fired craters forming a frame toward the position, and (c) the pressure-contact surface crater and the width-fired crater are provided at predetermined intervals, and the pressure-contact surface crater and the width-fired crater are provided at predetermined intervals. And a fuel supply pipe for supplying fuel to the fuel cell.

[0008]

In this manner, the gas pressure welding apparatus comprises a pressure contact crater forming a frame directed toward the end faces of the pair of metal bars, and a width grilling crater forming a frame directed near the axial direction of the end faces. And a fuel supply pipe having the press-contact surface crater and the width grilling crater provided at predetermined intervals. Therefore, when a pair of metal rods are pressed by gas, the end face is heated by the pressure contact crater, and at the same time, the heating in the vicinity of the end face in the axial direction is performed by the width grilling crater. Secondary heating required for gas pressure welding (bread grilling)
In this case, the reciprocating movement of the heating torch becomes unnecessary.

[0009]

As described above, since the heating of the end face and the baking are performed at the same time, the time required for heating and the bonding time are shortened, and the variation in the baking caused by the variation in the reciprocating movement of the heating torch is reduced. Since it cannot occur, uniform width printing can be performed, and the reliability of the bonding strength is improved. In addition, even when the gas pressure welding device is automated, there is no need to provide a reciprocating mechanism for moving the heating torch. Therefore, there is an advantage that the device is simplified and automation is facilitated.

[0010] For example, the plurality of press-contact surface craters are provided on a first plane including end surfaces of a pair of metal bars, and form a frame in a direction parallel to the first plane. The plurality of width grilling craters are provided, for example, on a pair of second planes parallel to the first plane separated by a predetermined distance on both sides in the axial direction of the end face, respectively, in a direction parallel to the first plane. Alternatively, the frame is formed in a direction forming a predetermined angle with the first plane so as to be separated from the end face toward the metal bar. Further, the plurality of width grilling craters are provided, for example, on the first plane, and the frames are formed on both sides in the axial direction of the metal bar in two directions forming a predetermined angle with the first plane. It may occur.

[0011] Preferably, the gas pressure welding device includes:
(d) a pressing force detecting device for detecting a pressing force by the pressing device, and (e) pressing means for pressing the pressing device until the pressing force becomes higher than a first pressure set in advance. Pressurizing and holding means for maintaining a pressurized state by the pressurizing device; heating means for heating the vicinity of the end faces of the pair of metal bars by the heating torch; and heating of the pair of metal bars. When the detected pressure is lower than the second pressure set lower than the first pressure determined by the diameter of the pair of metal bars, the pair of metal bars by the heating torch is used. Heating stop means for stopping the heating of the material, and the pressurizing device until the pressure becomes a third pressure set higher than the first pressure when the pressure becomes lower than the second pressure. Re-pressurizing means for pressurizing again A control device, and further comprising.

[0012] According to this configuration, when performing gas pressure contact, while the pressing force of the pressurizing device is detected by the pressing force detecting device, based on the detected pressing force, the control device is controlled by the pressurizing means. The pressurizing force is applied until the applied pressure becomes higher than the first pressure, and the pressurized state is held by pressurizing and holding means. The heating means heats the vicinity of the end faces of the pair of metal bars by the heating torch. When the pressing force becomes lower than the second pressure, the heating is stopped by the heating stopping means, and the pressing force is increased to the third pressure by the re-pressurizing means. Therefore, after the bar holding device and the heating torch are arranged at predetermined positions, all the steps of pressing and heating are performed by the control device, and the reliability of the joining strength is further improved. Either stop of heating by the heating stop means or start of pressurization by the re-pressurizing means may be performed first. However, when the pressurization is started first, it is preferable that the heating is stopped before the pressure is relatively low and the pressure is not increased to the third pressure.

Preferably, (f) the fuel supply pipes of the heating torch are separated from each other by a distance larger than the diameter of the metal bar at the distal end and are connected to each other at the base end. The gas pressure welding device comprises a pipe section and a common pipe section connected to a base end of the branch pipe section, and (g) the fuel supply pipe, wherein the pair of metal rods are formed of the branch pipe. The moving device further includes a moving device configured to move to a protruding position surrounded by the portion and a retracted position to be pulled out of the distal end of the branch pipe portion.

With this configuration, the fuel supply pipe of the heating torch continues from the branch pipe part whose distal end is separated from the metal rod by a distance larger than the diameter of the metal bar and the base end of the branch pipe part. On the other hand, the gas pressure welding device has a projecting position in which a pair of metal rods are surrounded by the branch pipe portion, and a retraction position in which the fuel supply pipe is pulled out from the tip of the branch pipe portion. And a moving device for moving the moving device to the second position. For this reason, the fuel supply pipe of the heating torch is located at the protruding position when heating the pair of metal bars, while the pair of metal bars is sufficiently heated, and the heating is not required. Later, before the pressure is increased to the third pressure to form a large bulge near the end face, the pair of metal rods is located at the retracted position where the metal rod is pulled out from the tip of the branch pipe. Let me do.

As described above, when the bulging portion is formed, the fuel supply pipe can be located at the retracted position. Therefore, the fuel supply pipe of the heating torch, the crater for the pressure contact surface, the crater for width grilling, and a pair of metal rods are provided. Is sufficient if the bulges are formed so as not to interfere with each other before the bulges are formed near the end faces of the pair of metal bars, and it is possible to reduce the distance between them as much as possible. It is possible. Therefore, the time required for heating can be further reduced by increasing the heating efficiency near the end faces of the pair of metal rods, and the necessary parts can be reliably heated even when performing pressure welding under strong wind to improve the bonding strength. Reliability is further improved.

Preferably, (h) the bar holding device is provided at a cylindrical portion having an open end and at the other end of the cylindrical portion, and includes a pair of metal bars. A first member having a first holding portion for holding one of the first and second members, a fitting portion fitted to the cylindrical portion and the cylinder so as to be relatively movable in a direction parallel to the axis and to be relatively non-rotatable about the axis; A second member having a second holding portion provided on one end side of the fitting portion and holding the other of the pair of metal bars,
(i) the pressurizing device includes one of the first member and the second member attached to the other of the first member and the second member such that the first holding portion and the second holding portion approach each other. The hydraulic cylinder is pressed in the axial direction.

According to this structure, the bar holding device includes the first member having the cylindrical portion and the first holding portion for holding one of the pair of metal bars, and the other metal bar. A second member having a second holding portion to be held and a fitting portion fitted to the cylindrical portion so as to be relatively movable in a direction parallel to the axial direction and to be incapable of relative rotation around the axial center; On the other hand, the pressurizing device includes a hydraulic cylinder that presses one of the first member and the second member toward the other. Therefore, the first holding unit and the second holding unit of the bar holding device are the first holding unit and the second holding unit.
When the cylindrical portion of the member and the fitting portion of the second member are pressed in the axial direction so as to approach each other, a pressing force in a direction approaching each other is given. Given by Therefore, by appropriately maintaining the hydraulic pressure of the hydraulic cylinder, the pressure applied to the pair of metal bars at the time of gas pressure welding can be set to an appropriate value, and the reliability of the joining strength can be further enhanced.

[0018]

An embodiment of the present invention will be described below with reference to the drawings. In the following description, the dimensional ratios in the drawings are not necessarily drawn accurately.

FIG. 1 shows an embodiment of a gas pressure welding apparatus according to the present invention, in which an automatic gas pressure welding apparatus 10 is used to attach a vertical reinforcing rod 12a to another reinforcing rod 12b. FIG. 4 is a diagram schematically illustrating a use state of connecting the two. The automatic gas pressure welding device 10 includes a rebar 12
a rod holding device 14 for holding a and b with their axial directions aligned and end faces abutting each other; a pressing cylinder 16 for applying a pressing force to the reinforcing bars 12a and b in a direction of pressing each other by hydraulic pressure; , A heating device 18 for heating the rebar 12, and a control device 20 for controlling the operation thereof. In the present embodiment, the reinforcing bar 12 corresponds to a metal bar, and the pressing cylinder 16 corresponds to a pressing device.

The rod holding device 14 is integrally fixed to the large-diameter sleeve 22 and the large-diameter sleeve 22 and the small-diameter sleeve 24 fitted so as to be relatively movable in the axial direction and relatively rotatable around the axial center. A reinforcing bar receiving member 26 is provided, and a reinforcing bar receiving member 28 is integrally fixed to the small-diameter sleeve 24. The reinforcing bar receiving members 26, 28 are fixed to the reinforcing bars 12b, a by tightening bolts 30, 32, respectively. It is designed to be fixed. In this embodiment, the large-diameter sleeve 2
2 corresponds to the cylindrical portion, the small-diameter sleeve 24 corresponds to the fitting portion, the reinforcing bar receiving members 26 and 28 correspond to the first holding member and the second holding member, respectively, and the large-diameter sleeve 22 and the reinforcing bar receiving member 2 correspond to each other.
6 constitutes a first member, and the small diameter sleeve 24 and the reinforcing bar receiving member 28 constitute a second member.

2, the notch 34 is formed in the large-diameter sleeve 22, which is a cross-sectional view taken along the line II-II of FIG. It projects outside from the notch 34 and is rotatable within a predetermined angle range. The angular position of the rebar receiving member 28 is determined by a pair of position adjusting bolts 40 screwed to a nut 38 attached to the large-diameter sleeve 22 via a notched ring member 36.
Thereby, the rebars 12a and 12b are adjusted so as to be positioned substantially concentrically. The small-diameter sleeve 24 is urged downward in FIG. 1 by a compression coil spring 42, and is always fitted in a socket 44 screwed to the large-diameter sleeve 22.
8 is held at the lower end position where it contacts, and is pressed upward by the pressing cylinder 16 locked by the socket 44 so that the reinforcing bar 12b contacts the reinforcing bar 12a.

The heating device 18 includes a heating torch 4
6, a moving device 48 for moving the heating torch 46 toward or away from the rebar 12, and a heating torch 46.
And an L-shaped fixing portion 54 having a reinforcing bar receiving member 52 having a structure similar to that of the reinforcing bar receiving member 26 of the bar holding device 14 at the distal end. Along with being provided on the upper side of 12 axial directions,
An L-shaped support portion 58 having an abutment member 56 at the distal end thereof, which is brought into contact with the reinforcing bar 12a, is provided on the lower side in the axial direction.
By fixing the contact member 56 directly on the reinforcing bar 12a while fixing it directly above the reinforcing bar receiving member 26 of the heating torch 4b.
6 is fixed to the reinforcing bar 12 in a state where it is located at the same height direction position as the end surfaces of the reinforcing bars 12a and 12b.

As shown in FIG. 3A, the heating torch 46 is connected to a common pipe 62 extending in a direction perpendicular to the axial direction of the reinforcing bar 12, and to the common pipe 62 at the base end. In addition, a fuel supply pipe is provided which includes a branch pipe section 63 which is separated from the rebar 12 by a distance equal to or slightly larger (for example, about 5 mm) than the diameter of the reinforcing bar 12 at the distal end. The branch pipe section 63 includes a pair of branch pipes 64a and 64b.
2, a pair of arc-shaped portions 66, 66 following the outer peripheral surface
Are formed respectively. These arc-shaped portions 66, 66
The three craters 68 for the press-contact surface each protruding toward the inner peripheral side and the two craters 68 between the three craters 68 for the press-contact surface are provided.
At the position, as shown in FIG.
2 are provided at both ends of the branch pipe 70 projecting from both sides in the axial direction in a direction parallel to the axial direction, for example, separated by about ten to several tens mm in the axial direction. 8 in total
And two width grilling craters 72.

The pressure contact crater 68 is provided such that its axial center is included in a first plane including a pressure contact surface 78 which is an end face of the rebars 12a and 12b which abut each other. The width grilling crater 72 has a pair of second planes (from the first plane) parallel to the first plane such that the axial direction of the crater 72 is separated from the first plane as the axial direction moves toward the inner peripheral side of the arc-shaped portion 66. Tens to several tens of mm on both sides of the reinforcing bar 12 in the axial direction
A predetermined angle from a plane at a distance
It is provided to form an angle of about °. For this reason,
As shown in FIG. 3 (c), the direction from the press-contact surface crater 68 to the direction parallel to the press-contact surface 78, that is, the direction perpendicular to the axial direction of the reinforcing bar 12, and from the width grilling crater 72 toward the inner peripheral side. In a direction forming an angle of, for example, about 10 ° with respect to the press contact surface 78 so as to be separated from the press contact surface 78 in the axial direction,
A flame (flame) is generated in each case, and the crater 68 for the press-contact surface heats the press-contact surface 78, and the crater 72 for the width grilling has its press-contact surface 7.
For example, a position is heated at a distance of about ten to several tens of mm above and below in the axial direction from 8. That is, the crater 68 for the press-contact surface forms a frame directed toward the press-contact surface 78, that is, the end face, and the crater 72 for width grilling forms a frame that is away from the press-contact surface 78 by a predetermined distance on both sides in the axial direction.

The two types of craters 68 and 72 are provided with high heat resistance by, for example, wrapping a thread made of a heat insulating material around the outer peripheral surface and further solidifying the outer peripheral surface with a water-soluble heat-resistant cement. Have been. Further, as shown in FIG. 1, the common pipe portion 62 is housed in the heating device main body 76 in a state of being fitted in the sleeve 74 so as not to move in the axial direction. In this embodiment,
As is apparent from the above configuration, the fuel supply pipe (that is, the common pipe section 62 and the branch pipe section 63) is moved by moving the entire heating torch 46.

In FIG. 1, the heating torch 46 is omitted for the sake of convenience, and is drawn in a state in which the branch pipe portion 63 is inclined. 78 are located on the same plane. In FIG. 3C, reference numeral 80 denotes a fuel supply passage formed inside the fuel supply pipe. FIG. 3 (c)
Shows only the right half of the section taken along the line cc in FIG. 3 (a).

The common pipe section 62 is also branched at an end opposite to the branch pipe section 63, and is branched via, for example, flow control devices 82 and 83 having solenoid valves and the like. Each is connected to an oxygen cylinder 84 and an acetylene cylinder 86. Therefore, the heating torch 46
A mixed gas having a mixing ratio determined by the flow rate adjusting devices 82 and 83 is supplied to the fuel supply pipe of the above.

The moving device 48 includes, for example, a drive motor 88, a pinion gear 89 attached to a rotation shaft of the drive motor 88, and a rod 90 having a rack gear meshed with the pinion gear 89. A connecting member 92 for connecting the rod 90 and the sleeve 74 so as to be relatively immovable in a direction parallel to the axial direction; and the sleeve 74 is relatively movable in the axial direction and axial direction in the heating device body 76. And a through-hole 94 penetrated so as to be relatively immovable in a direction perpendicular to the direction. In the moving device 48, the rod 90 is protruded from the heating device main body 76 by the rotation of the driving motor 88, so that the heating torch 46 is moved in a direction perpendicular to the axial direction so as to approach the rebar 12. On the other hand, when the rod 90 is drawn into the heating device main body 76 by the rotation of the driving motor 88, the heating torch 46 is moved in a direction perpendicular to the axial direction so as to be separated from the reinforcing bar 12. Thereby, the heating torch 46 (fuel supply pipe) is moved to a protruding position in which the rebar 12 is surrounded by the branch pipe 63 and a retraction position in which the rebar 12 is pulled out from the tip of the branch pipe 63.

The drive motor 88 is connected to the control device 2
The rotation direction is controlled by control relays CR1 and CR2, which will be described later, which are provided in 0. Also, the control device 2
0 is provided with a pump 96 for generating a hydraulic pressure applied to the pressing cylinder 16 connected to the bar holding device 14, and the hydraulic pressure is supplied to the pressing cylinder 16 according to the operation of a solenoid valve (not shown). The control device 20
The press-start switch 98 for starting the pump 96, the press-start switch 100 for starting the automatic gas pressure welding device 10, and the rebar 1
A diameter setting switch 102 for applying an appropriate pressure to the cylinder 16 according to the outer diameter of the cylinder 2 is provided.

FIGS. 4A and 4B are diagrams showing an electric control circuit and a hydraulic control circuit of the automatic gas pressure welding device 10, respectively. 4A, the control device 20 receives a pressure signal of the pressing cylinder 16 detected by the pressure sensor 104, a start signal of the preload start switch 98, and a start signal of the press-contact start switch 100, respectively. On the other hand, based on those input signals, a start signal SM for starting the motor 106 of the pump 96 and the pressing cylinder 16
Drive signal SSV1 for driving the solenoid valve of FIG.
Drive signal SSV for driving the 2,83 solenoid valves respectively
2, SSV2, and drive signals SR1 and SR2 for the drive relays CR1 and CR2 for driving the drive motor 88. In the present embodiment, the pressure sensor 104 corresponds to a pressure detection device.

In FIG. 4B, when the pump 96 is operated, the oil in the oil tank 108 is sent to the solenoid valve 114 of the pressing cylinder 16 via the check valves 110 and 112. When the drive signal SSV1 is not sent from the control device 20, the solenoid valve 114 is at the position shown in the figure and the input port and the output port are connected to apply pressure to the pressing cylinder 16. When the SSV1 is being input, the input port and the discharge port are connected by the operation of the solenoid, and the hydraulic pressure of the pressing cylinder 16 is reduced. In addition,
In the figure, reference numeral 120 denotes a pressure gauge for displaying the pressure of the hydraulic circuit, and reference numerals 122 and 124 denote relief valves for preventing the pressure of the hydraulic circuit from becoming excessive.

When the reinforcing bars 12a and 12b are connected by the automatic gas pressure welding apparatus 10 constructed as described above, first, the pressing surfaces 78 of the reinforcing bars 12a and 12b are respectively flat in the axial direction and flat with oxide. Process so that it does not. For this processing, for example, a cutting machine equipped with a disk-shaped rotary cutting tool having a processing blade made of a cemented carbide or the like on the outer peripheral surface is suitably used. It is to be noted that the rebar 12 whose end face (pressure contact face 78) is flattened by a sander or the like after fusing by an acetylene burner or the like can be similarly gas-pressure-contacted. Since it is desired to be as flat as possible, it is preferable to use a cutting machine as described above. After the rebar 12 is processed in this manner, as shown in FIG. 1, the pair of rebars 12a and 12b is held by the bar holding device 14 such that the end faces thereof abut each other with their axes substantially aligned. Then, the pressing cylinder 16 is mounted on the socket 44. Next, the heating device 18 is connected to the reinforcing bar 12b.
When the control device 20 is started by operating a start switch (not shown), the rebar 12
Gas pressure welding of a and b is performed. Hereinafter, the operation of the control device 20 will be described with reference to the flowchart shown in FIG. 5 and the pressure change diagram shown in FIG.

In step S1, it is determined whether or not the preload start operation has been performed, that is, whether or not the preload start switch 98 has been turned on. While the determination is negative, the process proceeds to step S17, where the drive signal SS
V1 is sent to the electromagnetic valve 114, and the pressing cylinder 16 is made to stand by in a state of being retracted. At time t _1,
If the above determination is affirmed, the routine proceeds to step S2, where the motor 1
06, the drive signal SM is sent to start the pump 96,
In step S3, the pressing cylinder 16 is advanced. Thereby, the reinforcing bar 12a is pressed toward the reinforcing bar 12b. In the following step S4, the rebar diameter D set in the diameter setting switch 102 is read. At this time, no drive signal is sent to the solenoid valve 114, and the solenoid valve 114 is located at the switching position shown in FIG.
In this embodiment, steps S2 to S6 correspond to a pressing unit.

Then, in step S5, as shown in FIG.
High pressure line pressure P of the indicated hydraulic circuit _L2(Pressure sensor 10
4) is read, and the process proceeds to step S6.
Is set to the first pressure P₁Larger than
It is determined whether or not it is gone. This first pressure P₁After
The third pressure P which is the secondary set pressure described above_ThreeSmaller than eg
 200-400kgf / cm^Two(However, the cross-sectional area of the reinforcing bar 12 is 1cm^TwoHit
Pressure. The following pressures are all the same).
Rebar diameter, rebar cross section 1cm^TwoPressure and pressure
It is determined by the pressure receiving area of the cylinder 16,
Diameter setting switch 1 read in step S4
The value corresponding to the rebar diameter D set by 02 is, for example,
The data stored in the RAM (not shown) in the control device 20 is stored in advance.
It is selected from the correspondences exemplified in Table 1 and used.
You. The third pressure P_ThreeAchieves a sufficiently high bonding strength
The pressing force of the reinforcing bar 12 is, for example, 350 kgf / cm^Twothat's all
It is determined to be.

[0035]

[Table 1]

If the determination in step S6 is affirmative, the process proceeds to step S7. If the determination is negative, the process returns to step S2 and the steps up to step S6 are repeated. When the high pressure line pressure P _L2 becomes larger than the first pressure P _{1 at} time t ₂ , step S
6 is affirmative, and in step S7, the motor 10
6, the drive signal SM is not sent, and the pump 96 is stopped. It should be noted that the check valve 110,
Since the backflow of oil is prevented by 112, the oil pressure of the pressing cylinder 16 cannot be reduced.

When a predetermined time (for example, about 3 seconds) has elapsed since the pump 96 was stopped and time t ₃ is reached, in step S8, the press-contact start switch 10 of the control device 20 is turned on.
It is determined whether or not 0 is turned on. If this determination is denied, the process returns to step S7 and waits.
If affirmative, the process proceeds to step S9, where the pilot torch 50 ignites the heating torch 46. And
When the drive signal SR1 (forward) is sent to the drive relay CR1 of the drive motor 88 in step S10, the rod 90 is protruded from the heating device main body 76, and the heating torch 46 is advanced toward the rebar 12. The rebar 12 is positioned at the position shown in FIG. 1 (ie, the protruding position at which the rebar 12 is surrounded by the branch pipe 63), and heating of the rebar 12 is started. At this time, in order to prevent oxidation of the press contact surface 78 of the reinforcing bar 12, the drive signals SSV2 and SSV3 are sent to electromagnetic valves (not shown) of the flow rate adjusting devices 82 and 83, thereby mixing the mixed gas supplied to the heating torch 46. The ratio is acetylene excess, and the reinforcing bar 12 is heated by the reducing flame. In this embodiment, step S7 corresponds to the pressure holding unit, and steps S9 and S10 correspond to the heating unit.

After the heating of the reinforcing bar 12 is started, the diameter of the reinforcing bar
A predetermined time defined by D (for example, the rebar diameter D is the nominal diameter
After about 40 seconds for D-25,
Since the vicinity of the press contact surface 78 gradually softens, the reinforcing bar 12 is pressed.
It is deformed by the pressure of the pressure cylinder 16.
You. Therefore, the pressing force of the pressing cylinder 16, that is, the pressure
High pressure line pressure P detected by sensor 104_L2The figure
T as shown in FIG. _ThreeAfter a lapse of a predetermined time from_Four
Until P₁To P_TwoGradually lowered towards
You. That is, the rebar 12 is kept until immediately after the heating is started.
Maintains the original shape as shown in Fig. 7 (a).
However, after a predetermined time has passed from the start of heating,
When softened, the nearby area is softened as shown in FIG. 7 (b).
The side is gradually expanded in the radial direction by the axial pressing force
A bulge 126 is formed. For this reason, high line pressure
P_L2Is reduced.

In step S11 following step S10,
The high pressure line pressure P reduced as described above._L2
Is a predetermined second pressure P_TwoIs smaller than
Is determined. If this judgment is denied, step
Returning to step S10, if affirmative, step S12
The following is performed: The second pressure P_TwoIs the first pressure P ₁
Than for example 20-40kgf / cm^Two Set to be low
Value.

At time t ₄ , the high pressure line pressure P _L2
It becomes less than the pressure P _2, the determination in step S11 is affirmative the process proceeds to step S12. Step S12
When the pump 96 is started by the drive signal SM being sent to the motor 106, the pressing cylinder 16
Is supplied to the rebar 12, and pressurization of the rebar 12 is started. When the pump 96 is time t ₅ has elapsed e.g. 2-3 seconds are allowed to start, when a drive signal SR2 (backward) is sent to the drive relay CR2 of the drive motor 88, the heating torch 46 Figure 1 is retracted toward the left side so as to be separated from the reinforcing bar 12. As a result, the heating torch 46 is positioned at the most retracted position where the rebar 12 is pulled out from the distal end of the branch pipe portion 63. When the drive signals SSV2 and SSV3 are no longer sent to the electromagnetic valves of the flow rate adjusting devices 82 and 83, respectively, the supply of gas to the heating torch 46 is stopped and the fire is extinguished. In this embodiment, steps S11 and S13 correspond to the heating stop means, and steps S11 and S12
Correspond to the re-pressurizing means, respectively.

When the pump 96 is started, as shown in FIG. 6, the pressing force of the reinforcing bar 12, that is, the high pressure line pressure P _L2 is gradually increased, and the reinforcing bar 12 has a bulging portion 126 which is larger than the state shown in FIG. 7 is increased in diameter and thickness.
You are directed to the state shown in (c). After the pump 96 is restarted, in step S14, it is determined whether or not the high-pressure line pressure P _L2 has become higher than a third pressure P ₃ set in advance. This third pressure P ₃ is
For example, the pressure is set to be higher than the first pressure P by about 50 kgf / cm ² .

While the determination in step S14 is negative, oil is supplied to the pressing cylinder 16 to
Although the high-pressure line pressure P _L2 is gradually increased, if it is determined at time t ₆ that the high-pressure line pressure P _L2 has become greater than the third pressure P ₃ , the process proceeds to step S15, where the drive signal SM is transmitted to the motor 106. Pump 96 is stopped by the stoppage of the pump. However, not been sent drive signal to the solenoid valve 114, and allowed to position the switching position shown in FIG. 4, as shown in FIG. 6, the pump 96 after stopping even pressure coercive in P ₃ I'm dripping. And
In step S16, after the pressing force is held for a predetermined period of time (for example, about 2 to 3 seconds), the time t
₇ , when the drive signal SSV1 is sent to the solenoid valve 114 in step S17, the pressing cylinder 16
Is retracted, and the gas pressure welding operation of the rebar 12 ends. FIG. 7C shows the state of the reinforcing bar 12 after the end of the gas pressure welding. The diameter of the bulging portion 126 is about 1.4 times the diameter D of the reinforcing bar, and the thickness is about 1.2 times the diameter D of the reinforcing bar.

Here, according to the present embodiment, the automatic gas pressure welding device 10 includes a pressure contact surface crater 68 that forms a frame directed to the pressure contact surface 78 for heating the pressure contact surface 78 of the reinforcing bars 12a and 12b. In order to heat a position near the axial center of the press contact surface 78, a width grilling crater 72 forming a frame directed to the position, and the pressure contact surface crater 68 and the width grilling crater 72 are provided at predetermined intervals. And a heating torch 46 having a fuel supply pipe (that is, a common pipe section 62 and a branch pipe section 63) for supplying fuel thereto. Therefore, when the rebars 12a and 12b are pressurized by gas, the press-contact surface crater 68 forms the press-contact surface 78.
At the same time as the heating, the heating in the vicinity of the axial center of the pressure contact surface 78 is performed by the width firing crater 72, and the secondary heating (width firing) required in the conventional gas pressure welding is performed.
In this case, the reciprocating movement of the heating torch 46 becomes unnecessary.

Accordingly, since the heating and the width burning of the press contact surface 78 are simultaneously performed, the time required for heating and the joining time are shortened, and the reciprocating movement of the heating torch 46 becomes unnecessary, resulting from the reciprocating movement. Therefore, uniform width printing can be performed, and the reliability of the bonding strength can be improved. Moreover, in the automatic gas pressure welding apparatus 10 as in the present embodiment, there is no need to provide a reciprocating mechanism for moving the heating torch 46, so that the apparatus is simplified.

Further, in the present embodiment, the width grilling crater 72 of the heating torch 46 is provided at a predetermined angle (for example, about 10 °) with respect to the first plane including the pressure contact surface 78. Since the frame is inclined with respect to the axial direction of the reinforcing bar 12, there is an advantage that backfire (flashback) hardly occurs.

Further, in the present embodiment, the pressure (high pressure line pressure) P _L2 by the pressing cylinder 16 is detected by the pressure sensor 104 during the gas pressure contact.
Based on the detected pressure P _L2 , the control device 20
The steps S2 to S6 corresponds to a pressurizing means with its pressure P _L2 is pressurized to be higher than the first pressure P _1, and held by the step S7 corresponding to the pressurized state to the pressure retaining means, heating Step S9 corresponding to the means
The rebar 12 is heated by the heating torch 46 by S10 and S10, and when the applied pressure P _L2 during heating becomes lower than the second pressure P ₂ , Step S11 corresponding to the heating stop means.
And to stop the heating by S13, the steps S11 and S12 corresponds to the re-pressurizing means pressurizing the pressure P _L2 to a third pressure P _3. for that reason,
After disposing the bar holding device 14 and the heating device 18 at predetermined positions, the control device 20 performs all the steps of pressing and heating, and the reliability of the joining strength of the reinforcing bar 12 is further enhanced.

In this embodiment, the heating torch 4
The fuel supply pipe of No. 6 has a branch pipe part 63 whose distal end is separated from each other by a distance larger than the diameter D of the reinforcing bar 12, and a common pipe part 62 continuing from the base end of the branch pipe part 63. On the other hand, the heating device 18 is provided with a moving device 48 for moving the fuel supply pipe to a protruding position where the rebar 12 is surrounded by the branch pipe portion 63 and a retraction position for pulling out the tip of the branch pipe portion 63. Have been. Therefore, while heating the rebar 12, the fuel supply pipe is located at the protruding position, while the rebar 12 is sufficiently heated and the heating is not required (that is, the determination in step S11 is affirmed). later, before the pressure P _L2 is large bulge 126 is formed on the pressed surface 78 near the third pressure P ₃ is boosts the rebar 12, as described above, the branch of the heating torches 46 in step S13 It is located at a retracted position where it is pulled out of the distal end of the tube portion 63.

Therefore, the branch pipe portion 6 of the heating torch 46
3 and the distance between the craters 68 and 72 and the reinforcing bar 12
Before the bulging portions 126 are formed near the second pressure contact surface 78, it is sufficient if the bulging portions 126 are formed so as not to interfere with each other, and the interval therebetween can be made as small as possible. Therefore, the time required for heating can be further shortened by increasing the heating efficiency of the press contact surface 78 of the reinforcing bar 12, and the necessary portion is reliably heated even when performing the press contact work under strong wind, so that the reliability of the joining strength is improved. Can be further enhanced.

According to the present embodiment, the bar holding device 1
4 is a first member having a rebar receiving member 26 for holding one rebar 12b and a large-diameter sleeve 22, and the other rebar 1
Reinforcement receiving member 28 holding 2a and its large-diameter sleeve 2
And a second member having a small-diameter sleeve 24 fitted so as to be relatively movable in the axial direction with the second cylinder 2. Of the rebar receiving member 26 side. Therefore, the rebar receiving members 26 and 28 of the rod holding device 14 are pressed in the axial direction so that the large-diameter sleeve 22 and the small-diameter sleeve 24 approach each other, so that the pressing force in the direction approaching each other is reduced. The pressing force is provided by a pressing cylinder 16 which is a hydraulic cylinder. Therefore, by keeping the hydraulic pressure of the pressing cylinder 16 appropriate,
Pressure P applied to reinforcing bar 12 when performing gas pressure welding
_L2 can be set to an appropriate value, and the reliability of bonding strength can be further improved.

Note that, in the above-described embodiment, FIG.
As shown in (a) to (c), the branch pipe 70 provided on the arc-shaped portion 66 is provided with a width grilling crater 72 which is provided at an angle of about 10 ° with respect to the press contact surface 78. Heating torch 46
However, for example, a heating torch 128 as shown in FIGS. 8A to 8C can be used.

The heating torch 128 has substantially the same shape as the heating torch 46, but the width grilling crater 7 provided in the branch pipe 70 is provided.
2 is provided so that the axial direction thereof is parallel to the first plane including the press contact surface 78. Therefore, as shown in FIG. 8 (c), the frame generated from the width grilling crater 72 is parallel to the pressing surface 78 in the same manner as the frame generated from the pressing surface crater 68. Is heated and the width grilling is performed at the same time, so that the same effect as in the above-described embodiment can be obtained.

FIGS. 9 (a) to 9 (c) show the gas pressure welding apparatus 1 described above.
FIG. 9 is a view showing still another heating torch 129 that can be used for the heating torch 129. The heating torch 129 also has substantially the same shape as the heating torch 46 as a whole, but as shown in FIGS. 9 (a) and 9 (b),
The branch pipe 70 is not provided in the arc-shaped portion 66, and the width firing crater 130 is provided in the arc-shaped portion 66 similarly to the pressure-contact surface crater 68. This width grilling crater 130 is shown in FIG.
As shown in (c), a fuel injection passage 132 is provided at the base portion, which is communicated with the fuel supply passage 80, and is branched at the distal end portion so as to extend toward both sides in the axial direction of the reinforcing bar 12. For this reason, when a mixed gas of oxygen and acetylene, for example, similar to that of the above-described embodiment is supplied through the fuel supply passage 80, as shown on the right side of FIG. A frame is formed at an angle of, for example, about 10 ° with respect to the plane including the surface 78, and thereby, a width-sintering process is performed to heat a position separated from the pressing surface 78 by, for example, about tens to several tens mm in the axial direction. The press-contact surface crater 68 forms a frame in a direction parallel to a plane including the press-contact surface 78 and heats the press-contact surface 78 as in the case of the heating torches 46 and 128 described above.

While the embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be embodied in other embodiments.

For example, in the above-described embodiment, the heating torches 46, 128, and 129 are each provided with three press-contact surface craters 68 and four width grilling craters 72 on the branch pipes 64a, b, respectively. Although two firing craters 130 were provided, each having the same size, for example, in the heating torches 46 and 128,
0 may be provided at each of the three arc-shaped portions 66, 66, and two pressure-contact craters 68 may be provided therebetween so that the positions of the two pressure-contact craters 68 are opposite to each other. May be larger than the width grilles 72, 130. These numbers and sizes can be appropriately changed so that the press-contact surface 78 of the reinforcing bar 12 and the vicinity thereof are in a heating state suitable for gas-pressure welding.

Further, the heating position of the reinforcing bar 12 by the width grilling craters 72 and 130 is set to a position separated from the press-contact surface 78 by about ten to several tens mm, but this distance depends on the reinforcing rod diameter D and the like. It is changed as appropriate. That is, the thickness (length in the axial direction) of the bulging portion 126 formed after the gas pressure welding is preferably about 1.2 D as described above.
Since it is necessary to soften to some extent up to a position separated by about 0.6 D, the axial distance of the heating position by the width grilling craters 72 and 130 must be increased as the rebar diameter D increases. In addition, a gap is generated between the portion heated by the frame formed by the crater 68 for the pressure contact surface and the portion heated by the frame formed by the craters 72 and 130 for the width grilling, since the rebar diameter D is large.
When a low temperature portion is formed, for example, the inner diameter of any of the craters is increased to increase the frame diameter, or
The width grilling craters 72 may be arranged in two or more stages in one direction separated from the pressure contact surface crater 68, or two or more width grilling craters 130 having different directions (angles) toward the frame may be provided.

In the embodiment, the crater 6 for the pressure contact surface is used.
8 and width grilling crater 72 (or 130) are both provided in a common fuel supply pipe (common pipe section 62 and branch pipe section 63) to supply fuel gas to these craters 68, 72 (or 130). Although the supply path 80 is common, a fuel supply pipe provided with the crater 68 for the pressure contact surface and a fuel supply pipe provided with the crater 72 (or 130) for the width grilling are separately provided, and the fuel supply pipes are provided separately. May be configured to supply the fuel gas. In this case, for example, by providing the flow rate adjusting devices 82 and 83 in the respective fuel supply pipes, the amount and the mixing ratio of the supplied gas are separately set for the pressure contact crater 68 and the width grilling crater 72 (or 130). , It is possible to change the size of the frame generated from both craters according to the rebar diameter D.

As the pressurizing device, in addition to the hydraulic cylinder (pressing cylinder 16) shown in the embodiment, a motor for simply driving the small-diameter sleeve 24 or the like may be used. However, in order to increase the reliability of the joining strength, the pressing force of the reinforcing bar 12 needs to be maintained at an appropriate value determined by the reinforcing bar diameter D. It is preferable to use a hydraulic cylinder that can provide the following. In the embodiment, the pressing cylinder 16 is configured to be detachable from the bar holding device 14, but may be integrally configured so as not to be removable.

A gear device including a drive motor 88, a pinion gear 89, and a rack gear has been used as a moving device 48 for separating the heating torch 46 from the rebar 12, but the moving device 48 is, for example, a ball screw. It may be constituted by a mechanism, a hydraulic cylinder or the like.

In the embodiment, the bar holding device 1
Although the heating device 4 and the heating device 18 are separately provided and attached to the reinforcing bar 12, they may be integrally formed.

Further, in the embodiment, the pressing cylinder 16 is held so that the pressing force during the gas pressure contact is maintained at P ₁ , P ₂ , and P ₃ respectively for a predetermined time as shown in FIG.
Has been driven, but the pressing force may be driven so as to be fluctuated by a relatively small width.

Further, in the embodiment, the case where the gas pressure welding device of the present invention is applied to the operation of connecting the reinforcing steel 12b to the reinforcing bar 12a standing upright has been described. Of course, the present invention can be similarly applied to a connection operation of the reinforcing bars 12 arranged in the horizontal direction, a connection operation of the reinforcing bars 12 that have not been constructed yet, and the like.

Further, in the embodiment, the case of performing the gas pressure welding of the reinforcing bar 12 as the metal bar is described.
The present invention can be similarly applied to gas pressure welding of various other metal bars.

Although not specifically exemplified, the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a use state of a gas pressure welding device according to one embodiment of the present invention.

FIG. 2 is a view showing a cross-sectional structure perpendicular to the axial direction of a rod holding device of the gas pressure welding device of FIG. 1;

3 (a) is a plan view showing in detail a heating torch used in the gas pressure welding device of FIG. 1, and FIG. 3 (b) is a plan view of FIG.
FIG. 3B is a cross-sectional view taken along a line b, and FIG. 3C is a cross-sectional view taken along a line c-c in FIG.

4 (a) is a diagram showing an electric circuit configuration of the gas pressure welding device of FIG. 1, and FIG. 4 (b) is a diagram showing a hydraulic circuit configuration.

FIG. 5 is a flowchart showing an example of an operation of a control device of the gas pressure welding device in FIG. 1;

FIG. 6 is a diagram showing a change in pressure of a reinforcing bar when gas pressure welding is performed according to the flowchart of FIG. 5;

7A and 7B are diagrams showing changes in the vicinity of the pressure contact surface of the reinforcing bar during gas pressure welding, wherein FIG. 7A shows a state before heating, FIG. 7B shows a state where heating and pressurization are performed, and FIG. Indicates the state after the end of the gas pressure welding.

FIG. 8 is a view showing another heating torch used in the gas pressure welding device of FIG. 1, wherein (a) to (c) are respectively (a) to (c) of FIG.
It is a figure corresponding to (c).

FIG. 9 is a view showing another heating torch used in the gas pressure welding apparatus of FIG. 1, wherein (a) to (c) are (a) to (c) of FIG.
It is a figure corresponding to (c).

[Explanation of symbols]

 12: Reinforcing bar (metal bar) 46: Heating torch 68: Crater for pressure contact surface 72: Crater for width grilling {62: Common pipe section 62, branch pipe section 63} (fuel supply pipe)

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location F23D 14/58 F23D 14/58 B (56) References JP-A-51-137647 (JP, A) JP-A-60-148686 (JP, A) JP-A-54-145344 (JP, A) JP-A-51-114351 (JP, A) Fully open Showa 53-124324 (JP, U) Really open Showa 52-41331 (JP, U) JP 7-9577 (JP, U) JP 35-32628 (JP, Y1) JP 32-7162 (JP, Y1) JP 30-3063 (JP, B1)

Claims (4)

(57) [Claims] 1. A bar holding device for holding a pair of metal bars with their axial directions aligned and their end faces abutting each other, and a pair of metal bars held by the bar holding device. A pressurizing device for pressing the metal bars in a direction of pressing each other, and a heating torch for heating the vicinity of the end surfaces of the pair of metal bars from the outer peripheral side thereof, and heating the pair of metal bars. A plurality of pressure contact surface craters forming a frame facing the end surface to heat the end surface from the outer peripheral side thereof, wherein the heating torch comprises: From a plurality of width grilling craters forming a frame directed toward the position to heat a position separated from the outer peripheral side by a predetermined distance on both sides in the axial direction from the outer peripheral side, the pressure contact surface crater and the width grilling crater are Predetermined A gas pressure welding device, comprising: a pressure supply surface crater and a fuel supply pipe for supplying fuel to the width grilling crater. 2. A pressurizing force detecting device for detecting a pressurizing force by the pressurizing device; a pressurizing means for pressurizing the pressurizing device until the pressurizing force becomes higher than a preset first pressure; Pressure holding means for holding the pressurized state by the pressurizing device, heating means for heating the vicinity of the end surfaces of the pair of metal bars by the heating torch, and during heating of the pair of metal bars, When the detected pressure is lower than the second pressure set lower than the first pressure defined by the diameter of the pair of metal bars, the pair of metal bars by the heating torch is used. Heating stop means for stopping the heating of the pressurizing device, and the pressurizing device until the pressurizing force becomes a third pressure set higher than the first pressure when the pressurizing force becomes lower than the second pressurizing force. A re-pressurizing means for re-pressurizing the Further gas pressure welding apparatus of claim 1, which comprises. 3. The fuel supply pipe of the heating torch is separated from each other by a distance larger than the diameter of the metal bar at the distal end, and is connected to each other at the base end. And a common pipe portion connected to a base end of the portion. The fuel supply pipe is formed by projecting a position where the pair of metal rods are surrounded by the branch pipe portion and a tip end of the branch pipe portion. 3. The gas pressure welding device according to claim 1, further comprising a moving device for moving to a retracted position to be pulled out. 4. A rod holding device, wherein the rod holding device is provided at a second end of the cylindrical portion with an open end and holds one of the pair of metal bars. A first member having a holding portion, a fitting portion fitted relative to the cylindrical portion and being relatively movable in a direction parallel to the axis and non-rotatable relative to the axis, and one end of the fitting portion. A second member having a second holding portion provided to hold the other of the pair of metal bars, and wherein the pressing device includes the first holding portion and the second holding portion. The first member and the second member so that
The gas pressure welding device according to any one of claims 1 to 3, wherein the device is a hydraulic cylinder that presses one of the members in the axial direction toward the other of the first member and the second member.