JP3217651B2 - 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 pressure welding device used for butt-joining reinforcing bars and the like.

[0002]

2. Description of the Related Art This type of pressure welding apparatus is known as a device capable of stably providing high reliability with a stable process and quality regardless of the skill of an operator in pressure welding work of reinforcing bars and rails, for example, Japanese Patent Publication No. 53-46181. And disclosed in Japanese Patent Publication No.

[0003] A conventional pressure welding device will be described with reference to Figs.

FIG. 5 and FIG. 6 are a perspective view and a schematic view showing the whole of the press contact device. As is apparent from these drawings, the pressure welding device includes a supporter 5, a hydraulic cylinder 6, a pump unit 7, a heating device 8, and a control device 10.

[0005] The supporting device 5 functions as a supporting means for supporting the two rebars 12 and 13 as members to be pressed in such a manner that they can approach each other in the direction in which they are to be pressed. However, in this embodiment, the direction in which the pressing is performed is the vertical direction indicated by the arrow Z.

As is particularly apparent from FIG.
Includes a base 16 formed in a substantially cylindrical and long shape, and a pair of grip heads 17 and 18 provided near and at one end of the base 16, respectively. The grip heads 17 and 18 have head bodies 17 a and 18 a having a substantially U-shaped cross-section so as to surround a majority of the rebars 12 and 13 in the circumferential direction.
bolts 17b and 18b which are screwed into screw holes provided in the holes a and 18a and lock the reinforcing bars 12 and 13 at the sharp end portions.

[0007] One grip head 17 is attached to the base 16.
Is movable in the longitudinal direction. That is, FIG.
As shown in FIG.
a is a slider 2 slidably provided in the base 16.
0 through a bracket 17c.

The bracket 17c is attached to the base 1
The inside and outside of the base portion 16 are communicated through a guide hole 16a (see FIG. 5) formed in 6, and move along the guide hole 16a.

A substantially annular small bracket 23 is fixed to the base 16 in the vicinity of the bracket 17c, and a bolt 24 is screwed into a screw hole formed through the small bracket 23. . The bolt 24 biases the bracket 17c to one side so as to prevent rattling when the grip head 17 moves, and applies a biasing force by smoothly slidingly contacting the bracket 17c at its tip. .

The other grip head 18 is fixed to the base 16 via a bracket 18c and does not move.

Next, the hydraulic cylinder 6 and the pump unit 7 will be described. The hydraulic cylinder 6 and the pump unit 7 constitute a pressurizing unit that presses the rebars 12 and 13 close to each other and pressurizes them.

As shown in FIGS. 7 and 8, the hydraulic cylinder 6 includes a cylinder tube 27a and a head cover 27b.
And a piston rod 28 protruding and retracting from the cylinder. The piston rod 28
Is protruded when pressurized oil is supplied from the pump unit 7. However, the retraction of the piston rod 28 is performed by a return spring (not shown) provided in the cylinder.
Done by

In the vicinity of the distal end of the cylinder tube 27a, for example, three locking pins 27c are provided along the circumferential direction.
The L-shaped locking hole 16b (see FIG. 7) formed in the base portion 16 of the supporter 5 has the locking pin 2
The engagement of the hydraulic cylinder 6 causes the hydraulic cylinder 6 to be mounted on the support 5 in a fixed state.

That is, in FIG.
b comprises an axial hole 16c and a circumferential hole 16d extending in the axial direction and the circumferential direction of the base portion 16, respectively. When mounting the hydraulic cylinder 6 on the base 16 of the support 5, first,
The locking pin 27c is inserted into the base 16 while being introduced into the axial hole 16c. Then, by slightly rotating the hydraulic cylinder 6, the locking pin 27c is inserted into the above-mentioned circumferential hole 16d, whereby a fixed state is established. When removing the hydraulic cylinder 6 from the support 5, the reverse procedure may be followed.

On the other hand, although not shown, the pump unit 7 includes a hydraulic pump, a motor for operating the hydraulic pump, a tank for storing oil to be pressurized and supplied by the hydraulic pump, and the like. Have. The supply of the pressurized oil when the piston rod 28 is projected and the return of the oil during the retraction operation are performed through the hydraulic hose 31.

As shown in FIG. 6, the pump unit 7
Inside, a potentiometer 33 as a displacement amount detecting means is provided.
Is provided. The potentiometer 33 has a resistor 33a and a contact 33b as a movable element that slides on the resistor 33a, and transmits a resistance value corresponding to the position of the contact 33b as a signal. A wire 35 is connected to the contact 33b at one end, and the other end of the wire 35 is connected to the piston rod 28 of the hydraulic cylinder 6 as shown in FIGS. However, as shown in FIGS. 7 and 8, the wire 35 is covered with a tube 36 (also shown in FIG. 5), and slides in the tube 36 to transmit a force.

As shown in FIGS. 5 and 6, a connection cable 38 is provided between the pump unit 7 and the control device 10.
The transmission of a signal from the potentiometer 33 to the control device 10 and the supply of power to the motor in the pump unit 7 through the control device 10 are performed via the connection cable 38. .

Next, the heating device 8 will be described.

The heating device 8 includes a reinforcing bar 1 as a material to be pressed.
It functions as a heating means for heating the mutual press contact portions 2 and 13 and the vicinity thereof.

As shown in FIGS. 5 and 6, the heating device 8
Is a crater arrangement pipe 41 having a substantially annular shape and a partially cut-out shape.
And a torch 42 having the crater arrangement pipe 41 attached to its tip.
And a burner driving device 45 that movably supports and moves the torch 42 in a predetermined direction.

As shown in FIGS. 5 and 6, the burner driving device 45 is provided with an arm 45a, and the burner driving device 45 is fixed to the supporter 5 with the arm 45a.
Specifically, as shown in FIGS. 5 and 7, a mounting shaft 47 having a male thread is fixed to the base 16 of the support 5, and the distal end of the arm 45 a and the vicinity thereof are respectively fixed. The burner driving device 45 can be easily attached by the principle of leverage based on engaging the attachment shaft 47 and the base portion 16 as an action point and a fulcrum. Similarly, the burner driving device 45 can be easily removed.

As is apparent from FIG. 7, a plurality of craters (not denoted by reference numerals) are juxtaposed along the inner circumference of the crater arrangement pipe 41, and acetylene and oxygen are supplied from each crater. Is supplied.

A torch 42 having the crater arrangement pipe 41 attached to the tip thereof supports the crater arrangement pipe 41 and introduces acetylene and oxygen into the crater arrangement pipe 41. The supply of acetylene and oxygen to the torch 42
As shown in FIG. 5 and FIG. 6, the operation is performed through an acetylene hose 49 and an oxygen hose 50 connected at one end to the rear end of the torch 42, respectively. The acetylene hose 49 and the oxygen hose 50 are short, and the other end is a burner driving machine 4.
5 are connected to various electromagnetic valves (not shown). Acetylene and oxygen supplied from the acetylene cylinder 53 and the oxygen cylinder 54 shown in FIG. 6 through another long acetylene hose 55 and the oxygen hose 56 reach these electromagnetic valves, and are appropriately supplied by switching the electromagnetic valves. You.

As shown in FIG. 5, a pilot burner 58 is attached to the torch 42, and acetylene is supplied to the pilot burner 58 through the electromagnetic valve. In the figure, reference numeral 59 designates a thin acetylene hose connected to the pilot burner 58 for introducing acetylene.

The burner driving device 45 includes the torch 4
2, a first support for supporting and moving the crater arrangement pipe 41 in a reciprocating (oscillating) manner in the axial direction (indicated by an arrow Z in FIGS. 5 and 7) of each of the reinforcing bars 12, 13; Driving means (not shown) and the first support driving means are movably supported in a plane perpendicular to the axial direction (a plane defined by arrows X and Y in FIGS. 5 and 7). And a second supporting and driving means for moving (circular movement).

As shown in FIGS. 5 and 6, a connection cable 63 is interposed between the burner driving device 45 and the control device 10. Power is supplied to the first and second support / drive units through the control device 10 through the connection cable 63.

The control device 10 is composed of a microcomputer, and controls the operation of the pump unit 7 and the burner driving device 45 based on a program stored in advance in a storage unit provided therein. This program is
These are set as optimal conditions based on many test data, and are set corresponding to reinforcing bars of various diameters.

More specifically, as shown in FIG. 9, the pressure welding step is divided into, for example, steps 1 to 14, and the set time, the set compression amount, the set burner amplitude, etc. of each step are standardized for each rebar size. The standard data of the rebar size is called according to the setting of the rebar size.

The setting of pressing conditions such as the diameter of a reinforcing bar to be pressed is performed by an operator operating a keyboard 10a provided on a front panel of the control device 10 (see FIG. 5). Above and to the side of the keyboard 10a, a display unit 10b and a printing unit 1 for sending out recording paper, respectively.
0c is provided so that the pressure contact condition can be confirmed and the examination material can be obtained.

Next, a description will be given of the principle and operation of the operation control of the press-contact device having the above-described configuration.

First, the principle of operation control is as follows.

Gas pressure welding of reinforcing bars, rails, and the like is a type of solid-state welding, and the quality of the joining condition is affected by variations in temperature, pressure, deformation of the joining surface, degree of oxidation, and the like. Therefore, in order to perform the pressure welding automatically, it is necessary to consider all the factors related thereto, but if the fluctuations of these factors are fixed, the pressure welding process can be controlled by the duration of each step.

That is, if the heating gas flow rate and the heating width expansion schedule are fixed, the temperature and the temperature distribution of the heating section become substantially constant, and if the maximum pressurizing pressure and the pressurizing schedule are determined, the size of the bulge of the joint is reduced. The amount of compression is almost fixed. This is the basic principle of temporally controlling the automatic pressure welding. When the pressure welding is performed on a fixed schedule, the amount of compression and its progress well correspond to the time progress of the pressure welding process.

By the way, the method of controlling the pressing process by time as described above is based on the premise that there is a certain correlation between the pressing and heating time, the heating temperature and the compression amount. However, if this relationship greatly changes due to external factors that cannot be controlled, for example, temperature or weather, time control will not be established.

Therefore, in the pressure welding apparatus, in addition to the time control described above, in a required step, the amount of compression of the rebar, that is, the amount of shrinkage, is shown in FIG.
3 and automatically detects the detected value.
You are going to give feedback. In particular,
When the value of the detected shrinkage reaches the shrinkage set and stored in advance, the process proceeds to the next step, and an error due to a change in the heating state during the program control period due to time is corrected.

That is, since the amount of shrinkage of the rebar is generated as a result of heating and pressurizing, if this is detected and used as an index for process control, direct control is different from indirect time control. It can be carried out. As described above, by using both the time control and the control based on the shrinkage allowance, it is possible to perform more reliable process control without being influenced by external factors. However, it is of course possible to perform control based on only the shrinkage allowance or control based on only time.

The operation of the pressure welding apparatus will be described based on the process chart shown in FIG. 9 and FIG. However, a description will be given for each of the dividing steps 1 to 14 shown in FIG.

The controller 10 controls this operation and various checks performed during the operation.

Step 1 in FIG. 9 is a step of preparing for the start of pressure welding, in which it is checked whether the initial conditions are satisfied. More specifically, the operator switches the start switch (not shown: burner driving device 45 shown in FIG. 5) from the state of step 0.
Is turned on once, first, it is checked whether or not the rebar size is specified. If the size is not set, the burner (general term of the crater arrangement pipe 41 and the torch 42) is retracted. An alarm (buzzer and lamp lighting on burner driver 45) is issued in the state. In this case, a worker operates a stop switch (not shown: burner driving device 4).
5) is turned on to release the alarm, and the size is set by operating the keyboard 10a provided in the control device 10.

When the size setting is completed, the position of the pressurizing piston rod 28 is checked based on the output of the potentiometer 33, that is, the position of the contact 33b. The position of the contact 33b may deviate from a predetermined range depending on how the wire 35 that transmits the movement of the piston rod 28 to the contact 33b is bent. In this case, the burner moves to the center and an alarm is issued. When the alarm is issued, the operator confirms and turns on the stop switch to stop the alarm, remove the cause such as the bending of the wire 35, and restart the operation.

If the position of the piston rod 28 is within a predetermined range, a check for slippage is continued.
That is, the motor in the pump unit 7 is rotated to operate the hydraulic pump, pressurize the rebars 12 and 13, sample the position of the piston rod 28 (output of the potentiometer 33) after 2 seconds, and then After pressurizing for 2 seconds, the piston rod position is sampled again and
If a difference of (mm) or more occurs, it is determined that slippage has occurred between the gripping heads 17 and 18 of the support 5 and the rebar, and an alarm is issued after pressurization is stopped. In this case, as in the preceding paragraph, the operator cancels the alarm with the stop switch, then retightens the grip heads 17 and 18 and restarts.

When the alarm does not sound, the operator operates the burner position setting knob (not shown) on the burner driving device 45 to set the burner position.
When the start switch is turned on again in accordance with (see FIG. 7), the process proceeds to step 2.

From step 2, the process enters the pressure welding step.

First, the electromagnetic valve of acetylene for combustion is opened and ignited by the acetylene flame of the pilot burner 58 (see FIG. 5). Then, after 0.5 seconds, the electromagnetic valves of acetylene for oxygen and reducing flame are opened. It is ignited and heating begins under a reducing atmosphere.

This step 2 is controlled by time and is continued for a set time. When the set time elapses, the process proceeds to step 3.

Step 3 is intended to check slippage between both grip heads 17 and 18 of the support 5 and the rebar during the step control by the shrinkage allowance in the following steps 4 to 6. That is, the hydraulic pumps are operated to pressurize the rebars 12 and 13. If the set shrinkage allowance in step 4 is reached in step 3, it is determined that slippage has occurred, and an alarm is issued during the period of step 3. .

If slippage occurs, the process control based on the shrinkage margin becomes inaccurate.
The process control in the process 6 is made independent of the shrinkage allowance, and is stepped by time control or manually by a start switch.

Step 4 is a step of primary pressurization in which the reinforcing bars are brought into close contact with each other to perform initial bonding. If the above-mentioned slippage does not occur, the process is performed based on the set shrinkage allowance. That is, a contraction allowance is detected based on the output of the potentiometer 33, and when the contraction allowance is reached, the process proceeds to the next step 5. In step 4, a time is also set, which is used when it is determined in step 3 that the slippage has occurred.

In step 5, a small amplitude (FIGS. 5 and 7) is applied to the burner in order to sufficiently raise the temperature near the rebar joint surface.
(Reciprocating motion in the direction of arrow Z). Then, pressurization is performed while detecting the shrinkage allowance by the potentiometer 33, and when the set shrinkage allowance is reached, the process proceeds to the next step.

The amplitude of the burner (reciprocating motion in the direction of arrow Z) is also given in steps 6 to 11 hereinafter.

In the process chart of FIG. 9, the expression "burner swing" means that the burner (consisting of the crater arrangement pipe 41 and the torch 42) is moved circularly in the XY plane in FIG. In this way, the heating is efficiently performed by such movement. This swing of the burner is performed from step 2 to step 11
Continuously.

The step 6 is often used mainly for joining an extremely large-diameter reinforcing bar, and is set according to heating conditions when a large amount of shrinkage is required in the first pressurization. However,
In step 6, unlike steps 4 and 5, when either the set shrinkage margin or the set time is satisfied, the process proceeds to the next step.

Steps 7 to 10 are performed under time control, the hydraulic pump is stopped, and the burner amplitude is gradually increased by steps 3 to 6 with a standard flame by decompression, and the burner amplitude is uniformly increased to the center of the reinforcing bar. Heat to the temperature.

Step 11, as shown in FIG. 10, is a step in which the joint between the reinforcing bars 12, 13 is subjected to a large deformation by secondary pressurization to increase the adhesive strength of the press contact, and is controlled by the shrinkage allowance. And time control are used together.

In step 12, the burner is extinguished, the swing of the burner is stopped, the burner is retracted, and only the hydraulic pump is operated to perform the boost. Also in this step 12, the control based on the shrinkage allowance and the time control are performed.

In step 13, the hydraulic pump is also stopped, and the residual pressure in the hydraulic hose 31 is maintained, and is controlled by time.

In step 14, which is the final step, the hydraulic pressure release valve of the hydraulic pump is opened by the same time control, and the piston rod 28 is retracted (retracting operation).
At the time of entering this step 14, the total shrinkage is
At the end of Step 4, the total time is displayed on the display unit 10b of the control device 10.

[0058]

In the above-described conventional pressure welding apparatus, in addition to time control, in an important step, the shrinkage allowance of the reinforcing steel joint is automatically detected, and the detected value is set to a predetermined reference value. When the shrinkage has been reached, the next step is being advanced. Therefore, it is said that a desired pressure welding is performed by correcting an error due to a change in the heating state during the program control period with time.

However, in the conventional pressure welding device, the contraction margin, that is, the distance is detected by the potentiometer 33 which follows the movement of the piston rod 28 via the wire 35. In such a configuration, when the wire 35 is compressed by the movement of the piston rod 28, the tube 36 contracts, and the amount of deformation indicated by the potentiometer 33 may temporarily change.

Further, when the wire 35 is forcibly bent due to some cause at the site where the pressure welding operation is performed, for example, when the worker is forcibly bent by hooking a limb, or when the wire 35 is naturally bent due to bending or the like, There is a concern that an axial distortion of 35 will occur and an error will occur in the detected value of the shrinkage allowance. Therefore, normal bonding may not be performed due to such a detection error.

For this reason, the present inventor has paid attention to the fact that perfect joining work may not be performed at the most important time in the pressure welding work in the above-mentioned conventional apparatus. That is, the detection of the shrinkage allowance occurring at the initial stage of the primary processing such as the step 4 shown in FIG. 9 is most important in this type of joining. In other words, since a constant pressing force as shown in FIG. 9 is applied to the piston rod 28, the condition of what temperature the heating temperature should be when shrinking by several mm is experimentally known. Therefore, when the heating temperature is sufficient and the shrinkage allowance is large under a certain temperature, that is, as in steps 12 and 13 in FIG. 9, the error in the detected value of the shrinkage allowance is controlled by the entire shrinkage allowance. So there is not much effect,
In the stage where the heating temperature is not sufficient at the initial stage such as the process 4, if an error in the detected value occurs, the apparatus determines that the temperature is sufficient and shifts to the next process. There's a problem.

As described above, if the heating temperature is not sufficient, it is determined that the shrinkage allowance is a predetermined detection value, and if it is determined that the temperature has reached the predetermined temperature, sufficient shrinkage can be performed in the subsequent steps. Even if a margin is obtained, a perfect joining state cannot be obtained.

In steps 7 to 10 shown in FIG. 9 of the related art, as shown in steps 4 to 6, there is little change in the shrinkage allowance, and it is not suitable to increase the burner amplitude using this amount of deformation. For this reason, after the primary pressurization of the step 6, the hydraulic pump is stopped, and the step of the burner amplitude 3 to 6 is performed while performing time control by the timer. However, although the switching of the burner amplitude is a necessary step, the time control may be performed under the condition that the device is used in a stable space. It is not always used under optimal conditions due to the effect of the burner strength and the like, and there is a possibility that optimal control may not be performed so that a uniform temperature is reached up to the center of the reinforcing bar.

Accordingly, an object of the present invention is to provide a pressure contact device capable of always accurately detecting a shrinkage allowance and a suitable hydraulic cylinder equipped with the pressure contact device. It is an object of the present invention to make it possible to control the pressure welding step by observing the depressurized pressure while keeping the residual pressure.

[0065]

[0066]

According to the present invention, there is provided a press-contact apparatus comprising: a support means for supporting each of the press-contact members so as to be freely accessible in a direction in which the press-contact members are to be pressed; A hydraulic cylinder to be pressurized, displacement amount detecting means mounted in the hydraulic cylinder, the movable element being engaged with the movable body, and the movable element being driven, and outputting the position of the movable element as an electric signal. A pump unit for supplying pressurized oil thereto, pressure detecting means provided in the pump unit for detecting a pressure applied to the movable body and a residual pressure (including a reduced pressure), and a pressure-contact member. Heating means for heating, and control means for performing control and time control based on information such as an output signal from the displacement amount detecting means and a pressure detected by the pressure detecting means, wherein the control means comprises the displacement amount detecting means To Detecting whether the shrinkage allowance has reached a predetermined set amount in a state of being pressurized in a predetermined pressurization region by the operation of the pump unit, and when the shrinkage allowance has reached a predetermined set amount, When the operation of the pump unit is stopped and the pressure detecting means observes the pressure reducing step and the pressure reaches a predetermined set pressure, the pump unit is operated again to pressurize the movable body. is there.

[0067]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a pressure contact device (including a hydraulic cylinder) as an embodiment of the present invention will be described with reference to FIGS. However, the pressure welding device of the present embodiment has the same configuration as the conventional pressure welding device described with reference to FIGS. 5 to 10 except for the portions described below, and a description of the configuration and operation of the entire device. Are omitted because they overlap, and only the main part will be described.

In the following description, the same components as those of the above-described conventional pressure welding device are denoted by the same reference numerals.

In the pressure welding apparatus according to the present invention, the hydraulic cylinder 70 and the pump unit 71 constituting the pressurizing means for bringing the two rebars 12 and 13 close to each other and pressurizing them are configured as follows.

As shown in FIG. 2, the hydraulic cylinder 70
The cylinder includes a cylinder composed of a cylinder tube 73a and a head cover 73b, and a piston rod 75 as a movable member that protrudes and retracts from the cylinder. The piston rod 75 is connected to the hydraulic hose 3 from the pump unit 71.
When the pressurized oil is supplied through 1, it protrudes.
However, the retraction of the piston rod 75 is performed by a return spring 76 provided in the cylinder.

In the drawings, reference numeral 78 indicates an oil seal interposed between the cylinder and the piston rod 75.

In the vicinity of the distal end of the cylinder tube 73a, for example, three locking pins 73c are provided along the circumferential direction.
Are provided, and the base portion 16 of the support 5 (see FIG. 1) is provided.
The hydraulic cylinder 70 is fixedly mounted on the support 5 by engaging the locking pin 73c with the L-shaped locking hole 16b (see FIG. 7) formed in the hydraulic cylinder 70.

That is, referring to FIG. 7, the locking hole 16b comprises an axial hole 16c and a circumferential hole 16d extending in the axial direction and the circumferential direction of the base portion 16, respectively. When mounting the hydraulic cylinder 70 on the base 16 of the support 5,
First, the locking pin 73c is inserted into the base 16 while being introduced into the axial hole 16c. Then, by slightly rotating the hydraulic cylinder 70, the locking pin 73c is inserted into the circumferential hole 16d, whereby a fixed state is established. To remove the hydraulic cylinder 70 from the supporter 5, the reverse procedure may be followed.

An ultrasonic displacement sensor 80 as displacement amount detecting means is integrally mounted on the hydraulic cylinder 70.

As shown in FIG. 2, the ultrasonic displacement sensor 80 has a magnetostrictive member 82 formed in a substantially columnar shape and a permanent magnet 83 formed in an annular shape. Then, the magnetostrictive member 82 is attached to the cylinder on the fixed side,
A permanent magnet 83 is attached as a movable element to a piston rod 75 as a movable body that is a movable side. That is, the mover engages with the movable body provided on the output side of the pressurizing means and is driven. More specifically, a male screw 85a is formed in the sensor main body 85 holding the magnetostrictive member 82, and the male screw 85a is fixed by screwing into a screw hole formed in the head cover 73b. The magnetostrictive member 82 itself is loosely inserted into a hole 75 a formed in the piston rod 75.

The permanent magnet 83 is fitted in the vicinity of the opening of the hole 75 a and is loosely fitted to the magnetostrictive member 82, and moves in the axial direction of the magnetostrictive member 82 with the movement of the piston rod 75. The position changes.

Here, the principle of the ultrasonic displacement sensor 80 will be described with reference to FIG. However, this FIG.
Are for understanding the principle, and therefore, the permanent magnet 83 is schematically shown as a flat plate.

In the figure, when a current pulse as shown by an arrow A is given to the magnetostrictive member 82, a circumferential magnetic field is generated in the magnetostrictive member 82. An axial magnetic field is applied only to the position where the permanent magnet 83 exists, and as a result, an oblique magnetic field as shown by a dotted line is generated. Therefore, torsion occurs in this portion of the magnetostrictive member 82. This phenomenon is called the Wiedemann effect. Since this torsion is a kind of vibration, the torsion propagates in the axial direction of the magnetostrictive member 82 at a specific speed of sound. The ultrasonic displacement sensor 80 measures the propagation time of the ultrasonic wave, and detects the position of the permanent magnet 83 with respect to the magnetostrictive member 82, that is, the amount of movement of the piston rod 75, that is, the amount of shrinkage of both rebars 12, 13 based on this. I do. Specifically, for example, the moving permanent magnet 83
Is 0 with respect to the effective stroke length of the magnetostrictive member 82.
A voltage converted into an analog electric signal of V to 10 V is extracted.

The supply of current to the magnetostrictive member 82 is controlled by a controller 87 in the pump unit 71 shown in FIGS. Therefore, the magnetostrictive member 82 and the controller 87 are connected by the connection cable 88 which is an electric wire.

On the other hand, the pump unit 71 is configured as follows.

As shown in FIG. 2, a high-pressure plunger pump 91 and a low-pressure pump 92
And an electric motor 94 for operating both pumps,
A tank 95 for storing oil to be pressurized and fed by each of the pumps is provided. Also, the hydraulic control valve 97,
Electromagnetic on-off valve 98, pressure sensor 1 as pressure detecting means
A built-in electronic pressure gauge 101 and the like as display means are provided. Pressure sensor 10 as this pressure detecting means
0 also detects the pressurized pressure and the residual pressure (including pressure reduction) in the path of the pump and the like.

In FIG. 2, reference numerals 103 and 1
Reference numeral 05 denotes a pressurized oil discharge port and a handle, respectively.

As shown in FIG. 1, the pump unit 7
A connection cable 107 (a part of which is also shown in FIG. 2) made of an electric wire is interposed between the controller 1 and the controller 10. The connection cable 107 transmits an electric signal from the ultrasonic displacement sensor 80 via the controller 87 to the control device 10 and supplies power to the electric motor 94 and the like.

In the pressure welding apparatus, when the two rebars 12 and 13 are pressed, the signal obtained by the ultrasonic displacement sensor 80 is used as a shrinkage allowance, whereby the pressure welding step is advanced. However, the step of the pressing process is performed in the same manner as the conventional pressing device shown in FIGS.

As is apparent here, the permanent magnet 83 of the ultrasonic displacement sensor 80 as a movable element is
It engages with a movable body provided on the output side of the pressurizing means and is driven by it. More specifically, the permanent magnet 83 is integral with a piston rod 75, and the piston rod 75 has a high rigidity through the slider 20 (see FIG. 7) and the grip head 17 (also see FIG. 7) provided on the support 5 and has a high rigidity. 12 is engaged.

Then, a signal corresponding to the position of the permanent magnet 83, ie, the amount of shrinkage of the rebar is output to the control device 10 as an electric signal.

According to such a configuration, the amount of shrinkage of the reinforcing bar is directly detected by the ultrasonic displacement sensor 80, and the detected value is always accurate without any error as in the conventional pressure welding apparatus via the wire 35 for signal transmission. Is obtained, and highly accurate pressure welding can be performed.

In the pressure welding apparatus according to the present invention, the connection cable 88 for transmitting a signal from the ultrasonic displacement sensor 80 is provided.
And 107 are electric wires, so that no matter how they are bent, there is no effect.

In the pressing apparatus, the ultrasonic displacement sensor 80 is integrally mounted on the hydraulic cylinder 70, and the permanent magnet 83 as a movable element of the ultrasonic displacement sensor 80 is attached to the piston rod 75 of the hydraulic cylinder 70. It is connected to. Thus, the configuration in which the ultrasonic displacement sensor 80 is integrated into the hydraulic cylinder 70 is compact, and effects such as easy movement and handling of the device can be obtained.

Next, the outline of the residual pressure holding step shown in steps 7 to 10 shown in FIG. 9 will be described with reference to the flowchart shown in FIG.

As shown in FIG. 4, in step S ₁ , the pumps 91, 92 are moved to a pressurization region where primary pressurization shown in FIG. 9 is reached.
Activate In this primary pressurizing step, it is detected whether or not the shrinkage allowance has reached the set amount of the primary pressurizing step, and the primary pressurizing step is advanced (step S ₂ ).

Next, when the set amount in the primary pressurizing step is reached, that is, when the step 6 shown in FIG.
The operations of Steps 1 and 92 are stopped to hold the residual pressure (Step S ₃ ). In step S _4, by observing the reduced pressure steps as shown in steps 7-10 of FIG. 9 by the pressure sensor 100,
The detected pressure signal is fed back to the control device 10. The burner amplitude is moved to the next step every time the switching set pressure is reached in this pressure reduction step. This process is repeated a required number of times (Step S _5).

Then, at the stage when the set pressure shown in the step 10, that is, the set pressure stored in the storage unit of the control device 10 is reached, the pump is operated to perform the pressurization up to the second pressurization (step S ₆ ). In this secondary pressurizing step, it is next determined whether or not the shrinkage allowance has reached a set amount (step S ₇ ).
In performing the extinguishing of the burner (step _S 8). And
In step S ₉ performs pressurizing pump stop. In other steps, the control is substantially the same as in the conventional step shown in FIG. The electronic manometer 101 as a display means constantly displays the pressure.

As described above, according to the present invention, the pressure (residual pressure or reduced pressure) is detected in the burner swinging steps 7 to 10, which are important steps in the pressure contact step, by using the pressure sensor as the pressure detecting means. Since the detected pressure signal is fed back to the control device 10, the work in each process can be reliably performed without being affected by the wind outside or the strength of the burner. In addition, this pressure detection step is not limited to the above-described steps, and can be controlled by feeding back a pressure signal in other steps, and the shrinkage margin and time control can be used together with this pressure detection. Of course.

In this embodiment, the case where the rebar is used as the material to be pressed is shown. However, it is needless to say that the present invention can be applied to pressure welding of other things such as rails. When handling another type of material to be pressed, the configuration of the support 5 and the like can be appropriately changed according to the shape.

In the present embodiment, acetylene and oxygen are used as the heating means. However, various heating means can be applied, for example, a method in which a current is applied to the press-contact portion to heat by the electric resistance of the press-contact portion. .

Further, in this embodiment, Wiedem
Although the ultrasonic displacement sensor 80 based on the ann effect is used as the displacement amount detecting means, various sensors using other principles can of course be used.

In this embodiment, the permanent magnet 83 is used as a movable element in the ultrasonic displacement sensor 80. On the contrary, the permanent magnet 83 is used as a fixed side and the magnetostrictive member 82 is used as a movable element. It is good also as a form.

[0099]

As described above, in the pressure contact device according to the present invention, the displacement amount detecting means for detecting the shrinkage allowance of the material to be pressed is engaged with the movable body and is driven to detect the displacement amount. Since the signal from the means is output to the control means as an electric signal, the displacement can be reliably detected. Further, in the pressure contact device according to the present invention, since the pressure on the movable body is detected by the pressure detecting means, the pressure change can be reliably detected, and the operation such as heating by the heating means can be reliably performed. Further, according to the present invention, since the shrinkage allowance of the material to be pressed is directly detected by the displacement amount detecting means, an accurate detection value can always be obtained without causing an error, and highly accurate pressure welding can be performed. .

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a press-contact device as an embodiment of the present invention.

FIG. 2 is a side view including a partial cross section showing a hydraulic cylinder and a pump unit which are main parts of the press-contact device shown in FIG.

FIG. 3 is a diagram for explaining the principle of an ultrasonic displacement sensor incorporated in the hydraulic cylinder shown in FIG. 2;

FIG. 4 is a flowchart when control is performed using the pressure sensor shown in FIG. 2;

FIG. 5 is a perspective view of a conventional pressure welding device.

FIG. 6 is a diagram schematically showing the press-contact device shown in FIG. 5;

FIG. 7 is a perspective view of a part of the pressure welding device shown in FIG. 5;

FIG. 8 is a perspective view of a part of the press contact device shown in FIG. 5;

FIG. 9 is a view showing a step in the press-contact device shown in FIG. 5;

FIG. 10 is a perspective view showing a state of a part of a process in the press-contact device shown in FIG. 5;

[Explanation of symbols]

 REFERENCE SIGNS LIST 5 support 8 heating device (heating means) 10 control device (control means) 12, 13 rebar (pressure-contacting member) 16 base portion 17 of support device 17, 18 grip head 31 hydraulic hose 41 crater arrangement pipe 42 torch 45 Burner drive 49,55 Acetylene hose 50,56 Oxygen hose 53 Acetylene cylinder 54 Oxygen cylinder 70 Hydraulic cylinder 71 Pump unit 75 Piston rod 80 Ultrasonic displacement sensor 82 Magnetostrictive member 83 Permanent magnet 87 Controller 88 Connection cable 91 High pressure plunger pump 92 Low pressure pump 94 Electric motor 95 Tank 107 Connection cable

Claims (1)

(57) [Claims] A supporting means for supporting each of the pressure-contact members so as to be freely accessible in a direction in which the pressure-contact members are to be pressed; A displacement amount detecting means which is mounted on the movable body, and which is engaged with the movable body and the movable element is driven to output the position of the movable element as an electric signal; and a pump which supplies pressurized oil to the hydraulic cylinder. A pressure detection unit provided in the pump unit and configured to detect a pressure applied to the movable body and a residual pressure (including a reduced pressure); a heating unit configured to heat the material to be pressed; and a displacement detection unit Control means for performing control and time control based on information such as an output signal from the pressure detection pressure of the pressure detection means, and the control means operates the pump unit by the displacement amount detection means. Detects whether the shrinkage allowance has reached a predetermined set amount in a state of being pressurized in a constant pressurization range, and stops the operation of the pump unit when the shrinkage allowance has reached a predetermined set amount. The pressure contact device is characterized in that when the pressure is detected by the pressure detecting means and a predetermined set pressure is reached, the pump unit is operated again to pressurize the movable body.