JP2004315958A - Thermal spraying wire feeder, and arc thermal spraying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal spraying feeder where thermal spraying wires are fed toward arc generation points at an always fixed speed, so that arcs are stably generated. <P>SOLUTION: Thermal spraying wires 1 and 1' are fed by push side feeding mechanisms 11 and 11' and pull side feeding mechanisms 12 and 12'. The pull side feeding mechanisms 12 and 12' are composed in such a manner that the feeding speed of the thermal spraying wires is held to set value by performing the fixed speed control of the pull side motor 20. The push side feeding mechanisms are composed in such a manner that the push side feeding force is held to fixed value suitable for controlling the amount of the thermal spraying wires fed into guide tubes 10 and 10' in the process of thermal spraying to the range enabling the fixed speed control of the pull side motor 20. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a spray wire feeding device used for an arc spray device, and an arc spray device using the spray wire feeding device.

  As is well known, an arc spraying apparatus includes a spray gun having a plurality of wire guides for guiding a supplied spray wire to a forward arc generating point, and a plurality of wire guides in the spray gun. A plurality of spraying wire feeding devices for supplying a spraying wire, wherein a voltage is applied between the plurality of spraying wires fed to the spray gun to generate an arc between the plurality of spraying wires at an arc generating point. To form a sprayed film on the object to be sprayed by causing the melted metal to scatter forward by being put on the gas flow discharged through the spray gun.

  In the arc spraying apparatus, since the operator operates the spray gun by hand, it is necessary to reduce the weight of the spray gun as much as possible.

  Further, in order to form a good thermal spray coating with an arc spraying apparatus, it is necessary to maintain a state in which the arc is continuously generated without interruption and without fluctuation in the arc length.

  One of the causes of the phenomenon that the arc is interrupted or the arc length fluctuates is a fluctuation in the wire feeding speed. If the arc length fluctuates due to the fluctuation of the wire feeding speed, the droplet size becomes uneven, the surface of the sprayed coating becomes uneven, and if the fluctuation of the wire feeding speed is large, the arc breaks. . Even if the arc is interrupted, when the wire is short-circuited again, the state shifts to the arc generation state again.However, when the wire is short-circuited, spatter is apt to occur, so the wire feeding speed fluctuates greatly and the arc breaks. When frequent occurrences occur, the amount of spatter mixed with the sprayed metal and sprayed on the object to be sprayed increases, and the quality of the sprayed coating deteriorates.

  Therefore, in order to stabilize the feeding of the spray wire, as shown in Patent Document 1, a guide tube for receiving and guiding the spray wire, a push-side drive roller driven by a push-side motor, and a push-side drive roller A push-side feeding mechanism that feeds the guide tube from the rear end side of the guide tube with the spraying wire interposed between the push-side driven roller urged toward the drive roller side and a front end side of the guide tube. Then, the sprayed wire that has passed through the guide tube is pulled out from the guide tube by being sandwiched between a pull-side drive roller driven by a pull-side motor and a pull-side driven roller urged toward the pull-side drive roller. A thermal spray wire feeder with a pull-side feed mechanism has been proposed.

In this thermal spray wire feeder, a push-side motor having a larger driving force than the pull-side motor is used, and the feed speed by the push-side feed mechanism is detected, and the detected feed speed is used as the pull-side motor. Of the pull-side feeding mechanism, the feeding speed by the push-side feeding mechanism is always controlled to be the same as the feeding speed by the push-side feeding mechanism.
Japanese Patent Publication No. 3-5222

  As shown in Patent Literature 1, when a thermal spray wire is fed by a push-pull method including a push-side feeding mechanism and a pull-side feeding mechanism, a pull-side motor having a small driving force is used. Therefore, the weight of the spray gun can be reduced as compared with the case where only the pull-side feeding mechanism is provided.

  Further, if the push-side motor and the pull-side motor can be controlled so that the feed speed by the push-side feed mechanism and the feed speed by the pull-side feed mechanism are always the same, the feed of the thermal spray wire can be performed. It can be performed stably.

  However, since the push-side motor is large and has large inertial force, the push-side motor is pushed by the change in the curved shape of the guide tube, which is inevitable due to a change in the posture of the operator during the spraying operation or a change in the direction of the spray gun. When the load on the side motor fluctuates significantly, the rotational speed cannot be instantaneously converged to the target value following the load fluctuation. For this reason, as shown in Patent Document 1, when a configuration is adopted in which the push-side motor is controlled at a constant speed, it is difficult to keep the rotation speed constant during the spraying operation, and it is difficult to always maintain the rotation speed during the spraying operation. Every time the load on the push-side motor changes due to the resulting change in the curved shape of the guide tube, it is unavoidable that the feeding speed of the push-side feeding mechanism fluctuates.

  Therefore, as shown in Patent Document 1, the feed speed by the push-side feed mechanism is fed back to the control unit of the pull-side motor, and the feed speed by the pull-side feed mechanism is fed by the push-side feed mechanism. When the control is performed so as to match the speed, each time the shape of the guide tube changes during the spraying operation, the feed speed of the spray wire on the spray gun side changes. In order to generate an arc stably, it is necessary to keep the wire feed speed on the spray gun side constant at all times, and avoid fluctuations in the wire feed speed due to changes in the spraying attitude as much as possible. There is a need.

  As described above, according to the configuration of Patent Literature 1, it is difficult to keep the feed rate of the spray wire on the spray gun side constant during the spraying operation, so that the arc can be stably formed during the spraying operation. In some cases, the thermal spray coating cannot be generated, and the quality of the thermal spray coating may be reduced.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a spraying wire feeder and a spraying apparatus using the same, which can always keep the feed of the spraying wire on the spray gun side constant during the spraying operation. It is in.

  The present invention provides a spray tube between a guide tube that receives and guides a spray wire, a push-side drive roller driven by a push-side motor, and a push-side driven roller urged toward the push-side drive roller. A push-side feeding mechanism for sandwiching and feeding the guide tube from the rear end side of the guide tube, and a spraying wire arranged in a spraying gun arranged on the front end side of the guide tube and passing through the guide tube. And a pull-side feed mechanism for pulling out from the guide tube between the pull-side drive roller driven by the pull-side motor and the pull-side driven roller urged toward the pull-side drive roller. For feeding devices.

  In the present invention, the push-side feed force applied to the spray wire from the push-side drive roller is Fpush, the pull-side feed force applied to the spray wire from the pull-side drive roller is Fpull, and the pull-side feed force Fpull that can be obtained during the spraying operation. The maximum value is Fpullmax, the maximum value of the resistance applied to the sprayed wire from the guide tube during spraying is Fxmax, and the resistance applied to the sprayed wire from the guide tube when inserting the sprayed wire into an empty guide tube is Fxo. The tensile strength of the wire is Fw, the maximum value of the feed resistance acting on the sprayed wire downstream of the pull-side feed mechanism in the feed direction is C1, and the maximum value of the feed resistance acting on the sprayed wire is upstream of the push-side feed mechanism in the feed direction. Assuming that the maximum value of the feed resistance acting on the spray wire is C2, the pull-side feed mechanism keeps the pull-side feed force Fpull in the range of Fxmax-Fxo <Fpull <Fw during the spraying operation. The pull side motor with constant speed control, and to keep the feed rate of the spray wire through pull side feed mechanism to a set value. Further, the push-side feeding mechanism maintains the push-side feeding force Fpush during the spraying operation at a constant value set in a range of Fxmax−Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2, and controls the amount of the spray wire fed into the guide tube. It is configured to always fall within a range that allows constant speed control of the pull-side motor.

  As described above, the pull-side feed mechanism controls the pull-side motor at a constant speed in order to maintain a constant feed rate of the sprayed wire during the spraying operation, and the push-side feed mechanism uses the push-side feed force during the spraying operation. By keeping Fpush at a constant value set in the range of Fxmax-Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2, the amount of the sprayed wire fed into the guide tube is always kept within a range enabling constant speed control of the pull-side motor. With this configuration, when the load on the push-side motor changes due to a change in the curved shape of the guide tube caused by a change in the spraying position during the spraying operation, the change is absorbed and the wire by the pull-side feeding mechanism is always used. During the spraying operation, the necessary amount of spray wire can be fed into the guide tube to perform control to keep the feed rate constant. When the feed load changes due to the change in the shape of the guide tube, the feed speed of the spray wire by the pull side feed mechanism is prevented from fluctuating, and the feed speed of the spray wire on the spray gun side is always Can be kept constant. Therefore, by using the thermal spray wire feeder according to the present invention, an arc can always be stably generated, and the quality of the thermal spray coating can be improved.

  When starting thermal spraying, it is necessary to first perform a preparation operation for inserting a thermal spraying wire into an empty guide tube and feeding the wire to the pull-side feeding mechanism. If this preparation is to be performed automatically, the push-side feeding mechanism can feed the sprayed wire toward the pull-side feeding mechanism without buckling the sprayed wire in the guide tube. Need to be kept.

  Here, when inserting the thermal spray wire into the empty guide tube, the resistance given to the thermal spray wire from the guide tube is Fxo, and the thermal spray wire is inserted into the empty guide tube and fed to the pull side feed mechanism side. When the buckling limit feeding force, which is the magnitude of the push-side feeding force when the spraying wire starts to buckle, is defined as Fb, the spraying wire is inserted into an empty guide tube in order to perform the above-described preparation work. It is necessary to configure the push-side feeding mechanism so as to keep the push-side feeding force Fpush in the range of Fxo + C2 <Fpush <Fb. Also in this case, during the spraying operation, the amount of the spray wire fed into the guide tube during the spraying operation is maintained while the push-side feeding force Fpush is maintained at a value set in the range of Fxmax−Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2. The push-side feeding mechanism is configured to always keep the pressure within a range that enables the constant speed control of the pull-side motor.

  In practicing the present invention, the push-side motor may be electrically controlled so that the push-side feed force Fpush is maintained at a constant value set in the range of Fxmax−Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2. However, it is not always easy to detect a change in the feed load caused by the deformation of the guide tube.

  Therefore, in a preferred embodiment of the present invention, the push-side motor pushes from the push-side motor so that the push-side feed force Fpush applied to the spray wire from the push-side drive roller is set to a value in the range of Fxmax−Fpullmax + C1 + C2 <Fpush <Fpull + Fxmax + C1 + C2. A torque transmission coupling for transmitting torque to the side drive roller is provided between the push side motor and the push side drive roller.

  The torque transmission coupling is, for example, provided so as to rotate with an input shaft that is rotationally driven by a push-side motor and a push-side drive roller, and is arranged to face the input shaft while sharing an axis with the input shaft. An output shaft, a magnetic disk coupled to the input shaft, and a magnetic disk configured to be housed therein, mounted on the output shaft so as to rotate with the output shaft, and supported rotatably with respect to the input shaft. And a pair of permanent magnets which are arranged to face each other with a magnetic disk interposed therebetween and fixed to the inner surface of the rotor housing. In this case, the pair of permanent magnets are magnetized in multiple poles such that magnetic poles of different polarities are alternately arranged in the circumferential direction.

  When the torque coupling as described above is provided, the push-side motor does not need to be particularly controlled, and only a motor that generates a torque corresponding to the maximum value of the expected required torque is used. Can be kept at the constant value.

  The present invention also provides a thermal spray gun having a plurality of wire guides for guiding the supplied thermal spray wire toward a forward arcing point, and supplying the thermal spray wires to a plurality of wire guides in the thermal spray gun. The present invention is applied to an arc spraying apparatus having a plurality of spraying wire feeding devices. In this case, the above-described configuration is used as each spraying wire feeding device.

  As described above, according to the present invention, the push-side feeding mechanism enables the constant-speed control of the pull-side motor by always controlling the amount of the sprayed wire fed into the guide tube without controlling the push-side motor at a constant speed. Since it is configured to fall within the range of the above, there is an advantage that the control for keeping the feeding speed of the sprayed wire fed toward the arc generating point constant can be performed stably and the spraying quality can be improved. .

  1 to 3 show an embodiment of an electric arc type thermal spraying apparatus according to the present invention.

  FIG. 1 is a perspective view schematically showing the configuration of the arc spraying device of the present embodiment, FIG. 2 is a longitudinal sectional view of a torque transmission coupling used in the arc spraying device of the present embodiment, and FIG. FIG. 3 is a perspective view showing an internal configuration of the coupling.

  As shown in FIG. 1, the electric arc type thermal spraying apparatus of the present embodiment includes wire guides 2 and 2 ′ for guiding two thermal spraying wires 1 and 1 ′ toward a forward arc generating point A. Thermal spray gun 3, two thermal spray wire feeders 4 and 4 'for supplying thermal spray wires 1 and 1' to wire guides 2 and 2 'in thermal spray gun 3, respectively, and thermal spray wire feeders 4 and 4' ′ Are provided with wire supply devices 5 and 5 ′ for supplying thermal spray wires 1 and 1 ′, respectively.

  The thermal spray gun 3 includes a housing 301 having a grip (not shown) at a lower portion thereof, and a nozzle portion 302 provided at a tip of the housing 301. Wire spray portions 2, 2 are provided inside the nozzle portion 302. 'Is arranged. The wire guides 2 and 2 'are formed of a tubular member whose tip is curved so as to be directed to a forward arc generating point A. Guide them to exchange. In this example, the wire guides 2, 2 'also serve as electrodes for supplying power to the spray wires 1, 1'. Although not particularly shown, a gas supply pipe is connected to the thermal spray gun 3 so that compressed air supplied through the gas supply pipe is jetted forward from the nozzle 302.

  The wire supply devices 5 and 5 'are rotatably supported directly above the containers 6 and 6' by the containers 6 and 6 'and the stands 7 and 7', respectively, in which the spray wires 1 and 1 'are coiled and accommodated. And the second guide rollers 9, 9 'disposed between the containers 6, 6' and the thermal spray wire feeders 4, 4 '. And the thermal spray wires 1, 1 'drawn out of the containers 6, 6', respectively, via the first guide rollers 8, 8 'and the second guide rollers 9, 9'. To supply.

  The thermal spray wire feeders 4 and 4 'receive guide tubes 10 and 10' for receiving and guiding the thermal spray wires 1 and 1 ', push-side feed mechanisms 11 and 11', and pull-side feed mechanisms 12 and 12 respectively. ´. The guide tubes 10 and 10 ′ are tubes made of a synthetic resin having flexibility such as polyethylene resin, and the front ends thereof are connected to the thermal spray gun 3.

  The push-side feeding mechanisms 11 and 11 ′ are respectively driven by push-side motors 13 and 13 ′ via torque couplings 14 and 14 ′, and push-side drive rollers 15 and 15 ′. On the 15 'side, there are provided push-side driven rollers 16, 16' urged by urging means (for example, springs) not shown, and the sprayed wires 1, 1 supplied from the wire supply devices 5, 5 ', respectively. Is inserted between the push-side drive rollers 15, 15 'and the push-side driven rollers 16, 16', and is fed into the two guide tubes from the rear end sides of the guide tubes 10, 10 '.

  The pull-side feeding mechanisms 12 and 12 ′ are arranged in the spray gun 3. One pull-side feeding mechanism 12 is attached to a pull-side drive roller 22 driven by a pull-side motor 20 via a speed reducer 21 and an urging means (for example, a spring) (not shown) is attached to the pull-side drive roller 22. It has a driven pull-side driven roller 23 and pulls out the thermal spray wire 1 that has passed through the guide tube 10 and feeds it to the wire guide portion 2 side.

  The other pull-side feeding mechanism 12 ′ has a rotating shaft coupled to the rotating shaft of the pull-side driving roller 22 via a transmission mechanism 25 including a timing belt and a pulley, and drives the pull-side feeding mechanism 12. A pull-side drive roller 22 ′ driven by the same motor as the pull-side drive roller 22 by the same motor as the pull-side drive roller 22, and a pull-side urged toward the pull-side drive roller 22 ′ by urging means (not shown). A driven roller 23 'is provided, and the sprayed wire 1' that has passed through the guide tube 10 'is pulled out and fed to the wire guide 2' side.

  The torque transmission couplings 14, 14 'are configured, for example, as follows. 2 and 3 show the configuration of one torque transmission coupling 14, but the other torque transmission coupling 14 'has the same configuration.

  The torque transmission coupling 14 shown in FIG. 2 and FIG. 3 is provided so as to rotate with the input shaft 13a rotated by the push-side motor and the push-side drive roller 15 and shares an axis with the input shaft 13a. An output shaft 15a opposed to the input shaft, a magnetic disk 30 made of a ferromagnetic material having a BH characteristic having hysteresis, and coupled to the input shaft 13a; The magnetic disk 30 is opposed to the rotor housing 33 which is configured to be loosely accommodated, is attached to the output shaft so as to rotate with the output shaft 15a, and is rotatably supported by the input shaft 13a. And a pair of permanent magnets 34 and 35 fixed to the inner surface of the rotor housing 33. The pair of permanent magnets 34 and 35 are magnetized in multiple poles such that magnetic poles of different polarities are alternately arranged in the circumferential direction.

  The input shaft 13a may be any shaft that is rotationally driven by the push-side motor, and is connected to the rotation shaft of the push-side motor itself or the rotation shaft of the motor directly or via a transmission mechanism such as a gear transmission mechanism. Any of the axes may be used. The output shaft 15a may be a shaft that rotates together with the push-side drive roller, and is connected to the rotation shaft of the push-side drive roller itself, or directly or via a transmission mechanism such as a gear transmission mechanism. Whichever axis is used.

  In the example shown in the figure, the rotor housing 33 is formed in two in the axial direction by cup-shaped half portions 33A and 33B, and one half portion 33A and the other half portion 33B are respectively provided in the bearings 31 and 33B. The disk-shaped permanent magnets 34 and 35 are attached to the bottom of the half portions 33A and 33B, respectively, and are rotatably supported by the input shaft 13a via the reference numeral 32. The half portions 33A and 33B constituting the rotor housing 33 are mutually fastened by through bolts (not shown), and the half portion 33B on the drive roller 15 side is fastened to a flange portion 15b provided at the tip of the output shaft 15a by bolts 36. I have.

  The axial dimensions of the half portions 33A and 33B constituting the rotor housing 33 and the thickness dimensions of the permanent magnets 34 and 35 are set to be equal to each other, and between the magnetic disk 30 and the magnet 34 and between the magnetic disk 30 and the magnet. 35, gaps G, G having the same gap length g are formed.

  As shown in FIG. 3, the pair of permanent magnets 34 and 35 are magnetized in multiple poles so that magnetic pole portions having different polarities are alternately arranged in the circumferential direction [thickness direction (axial direction of the input shaft and the output shaft). ), And is attached to the housing 33 in a state where the relative positional relationship between the magnetic poles in the circumferential direction can be adjusted.

  There are various mounting structures for mounting the magnets 34 and 35 so that the magnets 34 and 35 can be relatively adjusted in position. A disk-shaped magnet mounting plate 37 is rotatably supported, and one permanent magnet 34 is fixed to the magnet mounting plate 37. Teeth are engraved on the outer periphery of the magnet mounting plate 37, and a gear 38 meshed with the outer teeth of the magnet mounting plate 37 is rotatably supported by the half portion 33A in a state where it can be operated from the outside. . The other permanent magnet 35 is fixed to the housing half 33B by bonding or the like.

  In the illustrated example, the relative positional relationship between the magnetic pole portion of the permanent magnet 34 and the magnetic pole portion of the permanent magnet 35 can be adjusted by rotating the gear 38 and rotating the magnet mounting plate 37. It has become.

  In the illustrated torque transmission coupling 14, the magnetic flux generated from the permanent magnets 34 and 35 flows across the magnetic disk 30. When the magnetic disk 30 is rotated by the motor 13, a magnetic flux traversing the magnetic disk causes a force between the magnetic disk 30 and the permanent magnets 34 and 35 in a direction in which the relative rotation between the two is prevented. Works to transmit torque from the magnetic disk 30 to the rotor housing 33. The force transmitted from the magnetic disk 30 to the permanent magnets 34 and 35 is determined by the positional relationship between the magnetic poles of the permanent magnet 34 and the permanent magnet 35. The torque transmitted from the magnetic disk 30 to the permanent magnets 34 and 35 can be adjusted steplessly by adjusting the positional relationship between the permanent magnets 34 and 35 and changing the magnetic field between the two magnets. it can. In such a torque transmission coupling utilizing a magnetic coupling force, when the positional relationship between the magnetic pole of the permanent magnet 34 and the magnetic pole of the permanent magnet 35 is determined, the slip speed between the magnetic disk and the permanent magnet is determined. Irrespective of this, a constant torque is always transmitted. Assuming that the temperatures of the permanent magnet and the magnetic disk are constant, the torque transmitted from the motor 13 to the output shaft 15 a via the magnetic disk 30, the permanent magnets 34 and 35, and the rotor housing 33 is the rotational speed of the motor 13. Is kept constant even if changes.

  In the above-described arc spraying apparatus, when a voltage is applied between the spraying wires 1 and 1 'and both wires are fed toward the arc generating point A, the spraying wires 1 and 1' intersect at the arc generating point A and come into contact with each other. When this occurs, an arc is generated between both wires. Thereafter, by keeping the feed speed of the spray wires 1, 1 'constant, the arc between the two wires can be stably maintained. The constituent metal of the wire melted by the arc is scattered forward as fine droplets on the airflow flowing out of the nozzle portion 302, and adheres to the object to be sprayed disposed in front of the spray gun to form a spray coating. To form

  In order to obtain a high-quality thermal sprayed coating without surface roughness and without unevenness in thickness, it is necessary to stably maintain the arc without interruption, and for that purpose, aim at the arc generation point A. It is necessary to always feed the spray wires 1, 1 'at a constant speed.

  Here, as shown in FIG. 4, Fpush is the push-side feeding force applied to the spraying wire 1 from the push-side drive roller 15, Fpull is the pull-side feeding force applied to the spraying wire from the pull-side drive roller 22, The resistance force applied to the spray wire from the middle guide tube is Fx, the maximum value is Fxmax, and the feed resistance force acting on the spray wire 1 from the wire guide portion 2 or the like downstream from the pull-side feed mechanism 12 in the feed direction. C11, the feed resistance acting on the thermal spray wire 1 upstream of the push-side feed mechanism 11 in the feed direction is C22, the maximum pull-side feed force Fpull that can be obtained during the spraying operation is Fpullmax, and an empty guide tube. The resistance given to the spray wire from the guide tube when the spray wire 1 is inserted into 10 is Fxo, and the tensile strength of the spray wire 1 is Fw. Further, when a sprayed wire is inserted into the empty guide tube 10 and the wire is fed toward the pull-side feeding mechanism, the feeding force on the push side when the sprayed wire starts to buckle is reduced to a buckling limit feeding force. Fb. The buckling limit feeding force is determined by the degree of curvature of the guide tube, the inner diameter of the guide tube, the diameter of the spray wire, the material of the spray wire, and the like.

  Each feeding force and resistance force are forces applied in the length direction of the sprayed wire. The push-side feed force Fpush and the pull-side feed force Fpull can be calculated from the output torque of the push-side motor and the output torque of the pull-side motor, respectively.

  Further, the resistance force applied from each part was required when the wire was fed without the resistance force and when the wire was fed with the resistance force present. It can be obtained from the difference from the feeding power.

  For example, the maximum value of the resistance applied to the spraying wire from the guide tube is required when the spraying wire, which is in an unconstrained state, is fed only by the pull-side feeding mechanism without passing through the guide tube. It can be determined from the difference between the supplied power (calculated from the output torque of the motor) and the maximum value of the required power when the sprayed wire in the same state is fed through the guide tube.

  Further, the maximum value C1 of the feeding resistance force C11 acting on the spraying wire downstream of the pull-side feeding mechanism in the feeding direction is, for example, when the spraying wire is fed without passing through the wire guide portion. It can be obtained from the difference between the maximum value of the feeding force required for the feeding mechanism and the maximum value of the feeding force required for the pull-side feeding mechanism when the thermal spray wire is fed through the wire guide.

  Furthermore, the maximum value C2 of the feed resistance force C22 acting on the spraying wire on the upstream side of the push-side feed mechanism in the feed direction is not restricted as much as possible, for example, without providing a wire feeder (in a coil shape). The maximum value of the feeding force required for the push-side feeding mechanism when the spraying wire (not wound) is fed, and the push-side feeding mechanism when the spraying wire supplied from the wire feeder is fed. Can be obtained from the difference from the maximum value of the required feeding force.

  At the start of preparation for the thermal spraying operation, it is necessary to first pass the thermal spray wire through the guide tube, so that the push-side feeding force Fpush needs to satisfy the following relationship.

Fxo + C2 <Fpush ... (1)
At this time, in order to insert the thermal spray wire into the guide tube without buckling, Fxo needs to satisfy the relationship of Fxo <Fb. That is, in the case where the preparation operation for passing the thermal spray wire through the empty guide tube is automatically performed using the push-side feeding mechanism, the push-side feeding force Fpush needs to be set so as to satisfy the following expression.

Fxo + C2 <Fpush <Fb (2)
At the time of thermal spraying, the guide tube curves with various movements of the thermal spray gun, and the curved shape changes. Along with this change in the shape of the guide tube, the resistance force Fx applied from the guide tube to the spray wire during thermal spraying greatly changes, and the feed force (= Fpush + Fpull) required to overcome this resistance and feed the spray wire. ) Also changes. In order to be able to feed the spray wire during the spraying operation, the following relationship must be satisfied.

Fpull + Fpush> Fxmax + C1 + C2 (3)
In the present invention, the amount of the sprayed wire fed into the guide tube is kept at a constant value set to a size necessary to always keep the amount of the sprayed wire within a range that allows the constant speed control of the pull-side motor 20. Set the push-side feed force Fpush.

  As described above, in the present invention, since the push-side feeding force Fpush is maintained at a constant value, the pull-side feeding force Fpull needs to exceed the resistance (mainly the resistance due to friction) Fx of the guide tube.

  In the pull-side feeding mechanism, a servo motor that feeds back the rotation speed is used as the pull-side motor 20, and constant speed control is performed so that the pull-side feeding force Fpull is always maintained at a set value. In this type of motor, when an external force acting to change the rotation speed acts to maintain the rotation speed, the torque increases or decreases to maintain the rotation speed at a set value. If the rated torque of the pull-side motor is set so that the pull-side feed force Fpull necessary to maintain the rotation speed at the set value is obtained, the pull-up is performed so that the feed speed of the spray wire is maintained at the set value. The side motor can be controlled at a constant speed.

  In order to enable control to keep the feed rate of the sprayed wire by the pull-side feed mechanism constant during the spraying operation, the push-side feed force Fpush and the wire feed rate by the pull-side feed mechanism are kept constant. Therefore, the following relationship needs to be satisfied between the pull-side feeding force Fpull and the maximum value Fpullmax that can be obtained during the spraying operation.

Fpush−Fxmax−C1−C2 <Fpullmax (4)
If the value of the push-side feed force Fpush exceeds the value satisfying the expression (4), the load torque applied to the pull-side motor changes excessively, and the feed speed of the spray wire by the pull-side feed mechanism is to be kept constant. (Can exceed the set value).

  From equations (4) and (3), the push-side feeding force Fpush needs to be set in the following range.

Fxmax−Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2
… (5)
When the push-side feeding force Fpush (constant) is set so as to satisfy the expression (5), the amount of the spray wire fed into the guide tube is always controlled by the pull-side feeding mechanism to control the pull-side motor at a constant speed. The constant speed control of the pull-side motor is performed stably, and the wire feeding speed by the pull-side feeding mechanism is kept constant.

  The pull-side feeding force Fpull takes a constant value satisfying the following equation.

Fxmax−Fxo <Fpull <Fw (6)
That is, in the thermal spray wire feeder according to the present invention, the pull-side feed mechanism 12 controls the pull-side motor at a constant speed while maintaining the pull-side feed force Fpull during the spraying operation in the range of Fxmax−Fxo <Fpull <Fw. By controlling, the feeding speed of the spray wire by the pull-side feeding mechanism is maintained at a set value.

  Further, the push-side feed mechanism 11 keeps the push-side feed force Fpush in the range of Fxo + C2 <Fpush <Fb when inserting the spray wire into the empty guide tube, and reduces the push-side feed force Fpush to Fxmax− during the spraying operation. Keeping the constant value set in the range of Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2 so that the amount of the sprayed wire fed into the guide tube during the spraying operation is always within the range that enables the constant speed control of the pull-side motor. Is configured.

  With the above configuration, if the push-side feeding force Fpush is set as large as possible within a range satisfying the expression (5), the value of the pull-side feeding force Fpull obtained from the pull-side motor satisfies the expression (6). A value near the minimum value of the range, that is, a value slightly exceeding Fxmax-Fxo may be used. Therefore, a small-sized motor having a small rated output torque can be used as the pull-side motor, and the size and weight of the spray gun can be reduced, and the spraying workability can be improved.

  In addition, the spraying wire can be constantly supplied to the arc generating point at a constant speed during the spraying operation so that the arc can be generated stably without interruption, so that the quality of the sprayed coating can be improved.

  According to the results of experiments conducted by the present inventors, for example, when a polyethylene tube having a length of 5 [m] is used as a guide tube and the inner diameter of the guide tube is set to 1.5 times the wire diameter of the sprayed wire, pulling is performed. When the side feed force Fpull = 30 [N] and the push side feed force Fpush = 50 [N], the arc could be stably maintained, and good thermal spraying results were obtained.

  Note that, depending on the length and inner diameter of the guide tube, the push-side feeding force Fpush may be smaller than the pull-side feeding force Fpull. In this case, the pull-side motor cannot be made smaller than the push-side motor, but the effect of stably generating the arc without breaking the arc and improving the spraying quality can be obtained.

  In the above example, the case where two spray wires are fed to the spray gun is taken as an example. However, three spray wires are fed to the spray gun, and three-phase AC voltage is applied to the three spray wires. The present invention can also be applied to a case where an arc is generated by applying a voltage.

  In the above embodiment, the two spray wires 1, 1 'may be made of the same metal material or may be made of different metal materials.

  In the above-described embodiment, the push-side motors for driving the push-side feed mechanisms 11 and 11 ′ are separately provided in the respective feed mechanisms. However, a common motor is used as the push-side motor for both push-side feed mechanisms. Can also be used.

  In order to maintain a constant feed rate of a plurality of spray wires on the spray gun side, it is preferable to use a common motor as the motor of the pull-side feed mechanisms 12, 12 'as in the above embodiment. A pull-side motor may be separately used for each of the side feeding mechanisms 12 and 12 ′, and constant speed control may be performed so that both motors rotate at the same set speed.

  In the above embodiment, the preparation work for inserting the spray wire into the empty guide tube is automatically performed before the start of the spraying, but this preparation work is performed by observing the situation where the spray wire is inserted. Alternatively, it may be performed by manually operating a knob for adjusting the output of the push-side motor. As described above, when the preparatory work is performed manually, the push-side feeding mechanism sets the push-side feeding force Fpush to a fixed value in the range of Fxmax−Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2 (Equation (5)). It is sufficient that the amount of the sprayed wire fed into the guide tube is always kept within a range that allows constant control of the pull-side motor while keeping the value.

FIG. 1 is a perspective view schematically showing a configuration of an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a configuration example of a torque transmission coupling used in the present embodiment. FIG. 3 is a perspective view schematically showing an internal structure of the torque transmission coupling of FIG. 2. It is explanatory drawing for demonstrating the force applied to a thermal spray wire.

Explanation of reference numerals

1, 1 'Thermal spray wire 3 Thermal spray gun 4, 4' Thermal spray wire feeder 10, 10 'Guide tube 11, 11' Push side feed mechanism 12, 12 'Pull side feed mechanism 13, 13' Push side motor 14 , 14 'Torque transmission coupling 15, 15' Push-side drive roller 16, 16 'Push-side driven roller 20 Pull-side motor 22, 22' Pull-side drive roller 23, 23 'Pull-side driven roller.

Claims (8)

A guide tube that receives and guides the sprayed wire, and a guide that sandwiches the sprayed wire between a push-side drive roller driven by a push-side motor and a push-side driven roller that is biased toward the push-side drive roller. A push-side feeding mechanism that feeds the inside of the guide tube from the rear end side of the tube, and a spraying wire that is arranged in a spraying gun arranged on the front end side of the guide tube and passes through the guide tube. Thermal spray wire feeder comprising a pull-side feed roller driven by a pull-side motor and a pull-side feed mechanism that is pulled out of the guide tube between a pull-side driven roller urged toward the pull-side drive roller. In the feeding device,
Fpush is the push-side feeding force applied to the spraying wire from the push-side driving roller, and Fpull is the pull-side feeding force applied to the spraying wire from the pull-side driving roller. In order to keep the feeding speed at a set value, the maximum value of the pull-side feeding force Fpull can be Fpullmax, the maximum value of the resistance force applied to the spraying wire from the guide tube during the spraying operation is Fxmax, the empty guide. When inserting the spray wire into the tube, the resistance given to the spray wire from the guide tube is Fxo, the tensile strength of the spray wire is Fw, and the spraying is performed on the downstream side in the feeding direction from the pull-side feeding mechanism. The maximum value of the feed resistance acting on the wire is C1, and the maximum value of the feed resistance acting on the sprayed wire upstream of the push-side feeding mechanism in the feeding direction is C2. Come
The pull-side feed mechanism controls the pull-side motor at a constant speed while maintaining the pull-side feed force Fpull in the range of Fxmax−Fxo <Fpull <Fw during the spraying operation, and spraying by the pull-side feed mechanism. It is configured to keep the wire feed speed at the set value,
The push-side feed mechanism maintains the push-side feed force Fpush during spraying at a constant value set in a range of Fxmax−Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2, and feeds the spray wire into the guide tube. Is always within the range that allows constant speed control of the pull-side motor,
A spray wire feeding device characterized by the above-mentioned. A guide tube that receives and guides the sprayed wire, and a guide that sandwiches the sprayed wire between a push-side drive roller driven by a push-side motor and a push-side driven roller that is biased toward the push-side drive roller. A push-side feeding mechanism that feeds the inside of the guide tube from the rear end side of the tube, and a spraying wire that is arranged in a spraying gun arranged on the front end side of the guide tube and passes through the guide tube. Thermal spray wire feeder comprising a pull-side feed roller driven by a pull-side motor and a pull-side feed mechanism that is pulled out of the guide tube between a pull-side driven roller urged toward the pull-side drive roller. In the feeding device,
Fpush is the push-side feeding force applied to the spraying wire from the push-side driving roller, and Fpull is the pull-side feeding force applied to the spraying wire from the pull-side driving roller. In order to keep the feeding speed at a set value, the maximum value of the pull-side feeding force Fpull can be Fpullmax, the maximum value of the resistance force applied to the spraying wire from the guide tube during the spraying operation is Fxmax, the empty guide. When inserting the thermal spray wire into the tube, the resistance given to the thermal spray wire from the guide tube is Fxo, and when the thermal spray wire is inserted into the empty guide tube and fed to the pull side feed mechanism side The buckling limit feeding force, which is the magnitude of the push-side feeding force when the spraying wire starts to buckle, is Fb, the tensile strength of the spraying wire is Fw, C1 is the maximum value of the feed resistance acting on the spray wire on the downstream side in the feed direction from the feed mechanism on the nozzle side, and the feed force acting on the spray wire on the upstream side in the feed direction from the push mechanism on the push side. When the maximum value of the resistance is C2,
The pull-side feed mechanism controls the pull-side motor at a constant speed while maintaining the pull-side feed force Fpull in the range of Fxmax−Fxo <Fpull <Fw during the spraying operation, and spraying by the pull-side feed mechanism. It is configured to keep the wire feed speed at the set value,
The push-side feed mechanism keeps the push-side feed force Fpush in a range of Fxo + C2 <Fpush <Fb when inserting the spray wire into an empty guide tube, and keeps the push-side feed force Fpush during the spraying operation. Fxmax−Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2 The value of the spray wire fed into the guide tube during the spraying operation is kept within a range enabling constant control of the pull-side motor during the spraying operation. Is configured to fit into
A spray wire feeding device characterized by the above-mentioned.   The push-side drive roller and the push-side drive roller maintain the push-side feed force Fpush applied from the push-side drive roller to the spray wire at a constant value set in the range of Fxmax−Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2. 3. The thermal spray wire feeding device according to claim 1, wherein a torque transmission coupling for transmitting torque to the push wire is provided between the push-side motor and the push-side drive roller. The torque transmission coupling is provided so as to rotate with the input shaft that is rotationally driven by the push-side motor and the push-side drive roller, and is disposed to face the input shaft in a state of sharing the axis with the input shaft. An output shaft, a magnetic disk coupled to the input shaft, and a magnetic disk configured to be housed therein, attached to the output shaft so as to rotate with the output shaft, and with respect to the input shaft. A rotor housing rotatably supported and a pair of permanent magnets that are arranged to face each other with the magnetic disk interposed therebetween and fixed to the inner surface of the rotor housing,
The pair of permanent magnets are magnetized in multiple poles such that magnetic poles of different polarities are alternately arranged in the circumferential direction;
The thermal spray wire feeding device according to claim 3, characterized in that: A spray gun having a plurality of wire guides for guiding the supplied sprayed wire toward the forward arcing point, and a plurality of sprays for supplying the sprayed wires to the plurality of wire guides in the spray gun, respectively. An arc spraying device having a wire feeding device,
Each of the spraying wire feeding devices includes a guide tube having a front end connected to the spraying gun and configured to receive and guide the spraying wire from a rear end, and a push-side driving roller driven by a push-side motor. A push-side feeding mechanism that feeds the spraying wire between the guide tube and the push-side driven roller urged toward the push-side driving roller, and feeds the guide tube into the guide tube from the rear end side of the guide tube; The thermal spray wire, which is disposed in the gun and has passed through the guide tube, is pinched between a pull-side driving roller driven by a pull-side motor and a pull-side driven roller urged toward the pull-side driving roller. A pull-side feed mechanism that is pulled out from the guide tube.
Fpush is a push-side feeding force applied to the spraying wire from the push-side driving roller, Fpull is a pull-side feeding force applied to the spraying wire from the pull-side driving roller, and a spraying wire by a pull-side feeding mechanism during the spraying operation. The maximum value of the value that the pull-side feeding force Fpull can take to keep the feeding speed at the set value is Fpullmax, the maximum value of the resistance force applied to the spraying wire from the guide tube during the spraying operation is Fxmax, The resistance applied to the spraying wire from the guide tube when inserting the spraying wire into the guide tube is Fxo, the tensile strength of the wire is Fw, and the spraying is performed on the downstream side in the feeding direction from the pull-side feeding mechanism. The maximum value of the feed resistance acting on the wire is C1, and the maximum value of the feed resistance acting on the sprayed wire upstream of the push-side feeding mechanism in the feeding direction is C2. Come
The pull-side feed mechanism controls the pull-side motor at a constant speed while maintaining the pull-side feed force Fpull in the range of Fxmax−Fxo <Fpull <Fw during the spraying operation, and spraying by the pull-side feed mechanism. It is configured to keep the wire feed speed at the set value,
The push-side feed mechanism maintains the push-side feed force Fpush during spraying at a constant value set in a range of Fxmax−Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2, and feeds the spray wire into the guide tube. Is always within the range that allows constant speed control of the pull-side motor,
An arc spraying apparatus characterized in that: A spray gun having a plurality of wire guides for guiding the supplied sprayed wire toward the forward arcing point, and a plurality of sprays for supplying the sprayed wires to the plurality of wire guides in the spray gun, respectively. An arc spraying device having a wire feeding device,
Each of the spraying wire feeding devices includes a guide tube having a front end connected to the spraying gun and configured to receive and guide the spraying wire from a rear end, and a push-side driving roller driven by a push-side motor. A push-side feeding mechanism that feeds the spraying wire between the guide tube and the push-side driven roller urged toward the push-side driving roller, and feeds the guide tube into the guide tube from the rear end side of the guide tube; The thermal spray wire, which is disposed in the gun and has passed through the guide tube, is pinched between a pull-side driving roller driven by a pull-side motor and a pull-side driven roller urged toward the pull-side driving roller. A pull-side feed mechanism that is pulled out from the guide tube.
Fpush is a push-side feeding force applied to the spraying wire from the push-side driving roller, Fpull is a pull-side feeding force applied to the spraying wire from the pull-side driving roller, and a spraying wire by a pull-side feeding mechanism during the spraying operation. The maximum value of the value that the pull-side feeding force Fpull can take to keep the feeding speed at the set value is Fpullmax, the maximum value of the resistance force applied to the spraying wire from the guide tube during the spraying operation is Fxmax, When inserting the thermal spray wire into the guide tube, the resistance force applied to the thermal spray wire from the guide tube is Fxo, and the thermal spray wire is inserted into the empty guide tube and fed to the pull-side feed mechanism side. In this case, the buckling limit feed force, which is the magnitude of the push-side feed force when the sprayed wire starts to buckle, is Fb, the tensile strength of the wire is Fw, C1 is the maximum value of the feed resistance acting on the spray wire on the downstream side in the feed direction from the feed mechanism on the nozzle side, and the feed force acting on the spray wire on the upstream side in the feed direction from the push mechanism on the push side. When the maximum value of the resistance is C2,
The pull-side feed mechanism controls the pull-side motor at a constant speed while maintaining the pull-side feed force Fpull in the range of Fxmax−Fxo <Fpull <Fw during the spraying operation, and spraying by the pull-side feed mechanism. It is configured to keep the wire feed speed at the set value,
The push-side feed mechanism keeps the push-side feed force Fpush in a range of Fxo + C2 <Fpush <Fb when inserting the spray wire into an empty guide tube, and keeps the push-side feed force Fpush during the spraying operation. Fxmax−Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2 The value of the spray wire fed into the guide tube during the spraying operation is kept within a range enabling constant control of the pull-side motor during the spraying operation. Is configured to fit into
An arc spraying apparatus characterized in that:   The push-side drive roller and the push-side drive roller maintain the push-side feed force Fpush applied from the push-side drive roller to the spray wire at a constant value set in the range of Fxmax−Fpullmax + C1 + C2 <Fpush <Fpullmax + Fxmax + C1 + C2. 7. The arc spraying device according to claim 5, wherein a torque transmission coupling that transmits torque to the push-side motor and the push-side drive roller is provided. 8. The torque transmission coupling is provided so as to rotate with the input shaft that is rotationally driven by the push-side motor and the push-side drive roller, and is disposed to face the input shaft in a state of sharing the axis with the input shaft. An output shaft, a magnetic disk coupled to the input shaft, and a magnetic disk configured to be housed therein, attached to the output shaft so as to rotate with the output shaft, and with respect to the input shaft. A rotor housing rotatably supported and a pair of permanent magnets that are arranged to face each other with the magnetic disk interposed therebetween and fixed to the inner surface of the rotor housing,
The pair of permanent magnets are magnetized in multiple poles such that magnetic poles of different polarities are alternately arranged in the circumferential direction;
The arc spraying device according to claim 7, wherein:

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