JPH0245555B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an apparatus for coating a core wire of a coated arc welding rod with a coating material.

When manufacturing coated arc welding rods (hereinafter referred to as welding rods), the desired components are mixed around the core wire,
Wet-kneaded coating material (hereinafter referred to as flux)
It is well known that after coating a welding rod, it is sent to a drying process and dried to obtain a welding rod. However, it is required that the steps from the wet kneading step to the coating are carried out efficiently, and that the flux is coated uniformly around the core wire with sufficient adhesion strength. First, an example of a conventional flux coating apparatus will be explained based on the drawings.

Figure 1 shows the entire conventional coating equipment, and Figure 2 shows a plan cross-section, with the wet mixer omitted. In the figure, 1 supplies and stores flux sent from the wet mixer. A flux chute that can be cut out in predetermined amounts by an extrusion cylinder 2, 3 a flux forming and coating machine connected to the cutting opening position of the shoot 1, and 4 a base on which the forming and coating machine 3 is installed. stand, 20 is a core wire feeding machine, 18
1 is a cross conveyor, and 19 is a transport conveyor.

As shown in the figure, the flux forming and coating machine 3 is provided with two rotary disks 12 and 13 whose centers are fixed to a rotary shaft 9 which is supported by a rotary support part 14 on a base 4, A pair of flux cylinders 10, 11 are held symmetrically across the rotating shaft 9 by the rotating disks 12, 13, and one end side of the flux cylinders 10, 11 (opposite side of the die head) The pressure cylinder 5 for painting and the pressure cylinder 6 for molding are fixedly attached to a base 4 at intervals. On the other end sides of the pair of flux cylinders 10, 11, a forming presser cylinder 16 and a die head 17 are installed, which fit with the respective cylinders when the flux cylinders 10, 11 are stopped. Furthermore, when the pair of flux cylinders 10 and 11 stop at a predetermined position, the coating cylinder 5
The forming cylinder 6 is also provided at a position that coincides with the axis of the flux cylinders 10 and 11.
It is provided at a position that coincides with the axis of 1. moreover,
A flux receiver 15, which is integrated with the cutting opening of the flux shoot 1, is arranged between the forming cylinder 6 and the flux cylinder 10 or 11.

With this arrangement of the flux forming and coating machine 3, the piston 7 of the coating cylinder 5 is inserted into the flux cylinder 10 or 11 to supply flux under pressure to the die head 17, and also to supply flux to the die head 17 under pressure. The piston 8 is inserted through the flux receiver 15 into the flux cylinder 10 or 11, where it is inserted into the forming presser cylinder 16.
In combination with the piston, a flux molded product is formed. Moreover, by rotating the rotating disks 12 and 13 by 180 degrees, the pair of flux cylinders 10 and 11, which are arranged symmetrically across the rotation center line, coincide with the flux receiver 15 and the forming presser cylinder 16. It rotates alternately between a position corresponding to the die head 17 (flux forming position) and a position corresponding to the die head 17 (flux coating position). Note that the painting cylinder 5 and the forming cylinder 6 are generally hydraulic cylinders.

Further, the interchangeable operation of the pair of flux cylinders 10 and 11 is such that the flux cylinders can be accurately stopped at a predetermined position. Core wire feeder 20
consists of a cable storage box 20A and a feed roller 22, and supplies the cable to the die of the die head 17 at a desired speed via a cable guide. The direction in which the core wire is supplied and the direction in which the flux is supplied from the forming/coating machine 3 are arranged to be substantially perpendicular to each other.

In this way, a pair of flux cylinders 10, 1
The flux cylinder 10 is configured to be interchangeable by rotating the flux cylinder 10 in its respective position, and the tip surface 21 of the flux cylinder 10 that comes into contact with the die head 17 is provided with a groove for air bleeding along with the corresponding die head surface. .

When applying flux using the conventional coating equipment described above, a pair of flux cylinders can be used to apply flux.
The time from the completion of flux extrusion of one lot to the start of flux extrusion of the next lot is shortened, and the operating rate of the coating equipment is improved, resulting in higher productivity. However, since the molded flux is directly pressure-formed in a flux cylinder and lengthened by joining short cylindrical bodies, the molded flux is pressurized with air mixed in due to gaps, flakes of molded flux, etc. loaded. This flux cylinder can be rotated 180 degrees and used for painting. Therefore, although the air contained in the molding flux is vented in the gap 21 between the grooved surface of the flux cylinder and the die head, it is not sufficiently vented. In this case, the following problems occur in the painting process and the welding rod.

1. Due to the uneven distribution of air in the flux, the coating becomes eccentric.

2. The surface of the welding rod partially expands, making it soft and prone to surface flaws.

3. The degree to which the flux adheres to the core wire, the so-called degree of adhesion, is poor and causes the coating to fall off.

If air remains in the forming flux in this way, it will have a negative effect on the painting work and the welding rod, so a forming flux with a long cylindrical shape and high density that does not contain any air is required.

In addition, there is a technology to continuously form and paint flux using a screw under vacuum, but it is difficult to supply a fixed amount of flux to the die head at a constant pressure, and it is difficult to efficiently produce uniform, high-quality welding rods. is problematic.

The present invention was developed to solve the above-mentioned problems, and the gist of the present invention is to provide a forming cylinder having a main part with an inner diameter larger than that of the flux cylinder, a conical drawing part, and a vacuum degassing hole at the flux forming position. It is a device that is installed in a machine to create a long shaped flux that does not contain air, and uses this to coat the core wire with the flux. In a coating coating device that has a coating die head for discharging the coating at the front and is held interchangeably between two coating coating positions, the coating forming position has a coating die head located at the rear of the coating cylinder and coaxially therebetween. A molding cylinder having a main part with an inner diameter larger than that of the agent cylinder and a conical constriction part and having a vacuum degassing hole is provided, and a molding pressure cylinder is further provided at a position downstream of the cylinder, and a molding pressure cylinder is installed at a position downstream of the coating material cylinder at the position where the coating material is applied. A coating coating apparatus for a coated arc welding rod is provided with a pressurizing cylinder for coating, and a driving device for adjusting the longitudinal position is independently attached to a pair of coating cylinders.

Next, the structure of the coating material coating apparatus of the present invention will be explained using FIGS. 3 and 4.

FIG. 3 is a plan view of the entire coating coating apparatus of the present invention including a partial cross section, and FIGS. 4A, 4B, and 4C are plan views showing the process of flux forming. In the figure, 23 is a chute that supplies the flux sent from the wet mixer to the forming cylinder 54.
The base 55 has a forming cylinder 54 connected to the chute 23, and a flux cylinder 28 and a forming pressure cylinder 3 coaxially arranged before and after the forming cylinder 54.
6 is provided, and 29 is a flux cylinder in a flux coating position that rotates around the flux cylinder 28 and the rotating shaft 32 via a connecting rod 34;
A die head 42 and a coating pressure cylinder 41 are coaxially disposed before and after the flux cylinder 29.
46 is a core wire feeder, 43 is a cross conveyor, 44
is a conveyor for welding rods.

Further, the flux cylinders 28 and 29 are held by flux cylinder holders 30 and 31, and the flux cylinder holders 30 and 31 are held by flux cylinder holders 30 and 31.
Air cylinders 33 and 33', which are driving devices for sliding the flux cylinders 28 and 29, are attached to the cylinders 33 and 33', which are rotated 180 degrees around a rotating shaft 32 by a driving device (not shown) to move the flux forming position and the flux. It has a structure that accurately stops at the painting position alternately. The flux cylinder 28 at the coating material forming position is moved to the rear position (to the right in the drawing) by the air cylinder 33 and the tip 2 of the forming cylinder 54 is moved to the rear position (rightward in the drawing) by the air cylinder 33.
It is joined with 7. The forming cylinder 54 has a cylindrical main part 25 having a larger diameter than the inside diameter of the flux cylinder 28, a conical constriction part 26 having a predetermined angle θ, and a short cylinder having the same diameter as the inside diameter of the flux cylinder 28 at the tip. It has a structure with a shaped part. A molding pressure piston 35 and a molding pressure cylinder (hydraulic type) are provided at the rear of the molding cylinder 54, and a vacuum degassing hole 49 connected to a vacuum device (not shown) is provided in the chute 23 connected to the molding cylinder 54. An air cutoff valve 50 and a device (air cylinder) 52 for driving the air cutoff valve are attached. Furthermore, a forming presser cylinder 39 and a forming presser piston 37 are coaxially provided in front of the flux cylinder 28.

Next, the flux cylinder 29 in the flux coating position is held by a flux cylinder holder 31 and joined to the die head 42 by a sliding air cylinder 33'.
A painting pressurizing piston 40 and a painting pressurizing cylinder (hydraulic) 41 are provided at a rear position of the flux cylinder 29.

Feed roller 47 of core wire feeder 46, guide pipe 48, die head 42, cross conveyor 4
3 are installed coaxially and horizontally, and the flux forming position is below the guide pipe 48.

Flux forming by the flux cylinder 28, forming cylinder 54, forming pressurizing piston 35, and forming presser piston 37 provided coaxially in the above-mentioned flux forming apparatus will be described in detail using Fig. 4 A, B, and C. do. When a predetermined amount of flux 56 corresponding to the internal volume of the flux cylinder 29 is supplied from the chute 23, the air cutoff valve 50 is moved by the air cylinder 52 to a position 50 shown by a broken line to shut off and create an airtight state. At the same time, the flux cylinder 28 is connected to the air cylinder 3.
3 in an airtight manner with the forming cylinder 54, and the forming presser piston 37 is advanced by the presser cylinder (hydraulic type) 39 to the distal end 27 of the flux cylinder 28 as shown in FIG. 38 brings the airtight state. The rear part of the flux cylinder 28, on the other hand, is made airtight by a seal 24 which contacts the piston rod of a forming pressure piston 35 mounted on the inner surface of the rearmost part of the forming cylinder. With such a configuration, the molding cylinder 54 is brought into a sealed state, and then the air is evacuated through the evacuation hole 49. After vacuum degassing, the molding pressurizing piston 35 is advanced to pressurize the flux 56 as shown in FIG.
It is press-fitted into the cylindrical main part 25 of the forming cylinder 54, and is squeezed to a predetermined diameter by the conical drawing part 26, and is extruded from the forming cylinder 54 as a forming flux. Press the molded flux onto the molding piston 3
At step 7, the molding presser piston 38 receives a pressure slightly lower than the pressing force of the molding pressurizing piston 35, and the molding presser piston 38 sequentially retreats (to the left position in the drawing) to start flux molding, and as shown in FIG. 28 and completes the flux forming process. Vacuum degassing is preferably started at the same time as the molding cylinder is sealed and continued until the flux molding is completed.

On the other hand, the flux cylinder 29 in the flux coating position is slid against the flux cylinder holder 31 by the air cylinder 33' and is press-connected to the die head 42, and the piston 40 at the rear of the flux cylinder 29 moves forward. The molded flux in the flux cylinder 29 is extruded and coated on the core wire.

As soon as the flux forming and coating of the flux cylinders 28, 29 is completed, each piston retreats, and then the air cylinders 33, 33'
After the flux cylinders 28, 29 are disconnected from the forming cylinder 54 and the die head 42 by the , the flux cylinders 28, 29 are rotated 180 degrees around a rotating shaft 32 connected to a drive source (not shown). and stops at a predetermined position, and the next flux forming coating is immediately started again in the same manner as described above. Therefore, the flux cylinders 28 and 29 are rotated alternately between the coating material forming position and the coating position and are interchanged to perform continuous coating. In the second and subsequent flux forming steps, the airtightness at the tip of the forming cylinder 54 becomes even higher due to the flux 56' filled in the previous flux forming and remaining in the conical constricted portion 26 of the forming cylinder 54.

The above illustrated example shows an example of the present invention, and can be modified as appropriate within the scope of the technical idea of the present invention. For example, changing the position of the vacuum degassing hole 49 to the main part 25 of the forming cylinder 54, installing the air cylinder 33 on the base 55, and connecting the air cylinder drive shaft and the flux cylinder when the flux cylinders 28 and 29 are stopped. It is possible to adopt a change to a structure in which the seal is slid by hand, a change in an air-blocking seal structure, etc. as appropriate. Note that although the chute 23 is erected, the chute 23 is shown in a plan view for convenience in the drawings.

Next, the operation of applying flux to a welding rod core wire using the apparatus of the present invention will be explained.

First, the molding pressure piston 35 is located at the rearmost position (FIG. 4A), the flux cylinder 28 is joined to the molding cylinder 54 by the air cylinder 33, and the molding presser piston 37 is located at the frontmost position (FIG. 4A). In this state, a predetermined amount of flux 5 is applied from the chute 23.
6 is turned on, and the shutoff valve 50 provided in the chute 23 is advanced to the 50' position to shut off the outside air.
Therefore, the inside of the molding cylinder 54 into which the flux 56 has been introduced is isolated from the outside air, and the vacuum degassing hole 49 is closed.
When the inside of the molding cylinder 54 is deaerated and becomes a vacuum state (approximately -700 mmHg), the molding pressure piston 35 is advanced, and the flux 56 is pressurized into the main part 25 of the molding cylinder 54. At the same time as above, the flux presser piston 37 is moved back to a predetermined pressure to move the densely formed flux into the flux cylinder 28, and the forming pressure piston 35 shown in FIG. Flux forming is completed with the presser piston 37 at the rearmost position. Next, the flux cylinder 28 filled with flux is transferred to the air cylinder 3.
3, the molding flux is slid (for example, several mm, a rotatable distance) to release the connection with the molding cylinder 54, and is rotated by the rotating shaft 32 to shear the integral molding flux, The flux cylinder 29 is rotated by 180 degrees and is replaced with the flux cylinder 29 which was in the flux coating position and stopped at the flux coating position, and the flux cylinder 29 is rotated and stopped at the flux forming position. The flux cylinder 29 moved to this flux coating position is molded and filled with flux by the same operation as described above, but the high-density flux 56' from the previous flux molding is applied to the molding cylinder 54.
Since the gas remains densely in the constricted end portion 26 of the molding cylinder 54, the airtightness at the front portion of the forming cylinder 54 is improved, and the degassing efficiency is increased from the second time onwards.

On the other hand, the flux cylinder 28 that has been moved to the flux coating position slides forward within the flux cylinder holder 30 by the drive of the air cylinder 33 and is joined to the die head 42. At the same time as the joining is detected, the coating pressurizing piston 40 moves forward and is inserted into the flux cylinder 28, and pressurizes the flux so that the flux passes through the die head 42 and is extruded from the tip die.
On the other hand, the core wire is continuously and concentrically fed from the core wire feeder 46 at a predetermined speed to the tip end die of the die head 42, and the flux is uniformly applied around the core wire and extruded from the die to coat the core wire. The welding rod becomes a welding rod, passes through the cross conveyor 43, collides with the contact plate 45, is placed on the conveyor 44, and is sent to the next process.

At the same time that all the flux in the flux cylinder 28 at the flux coating position is pushed out under pressure, the coating pressurizing piston 35 moves back and is no longer inserted into the flux cylinder 28. The connection is also released and it becomes possible to rotate and move. During the time that the flux cylinder 28 is in the flux coating position, the flux cylinder 29 in the flux forming position has completed the entire flux forming and filling process and is ready to be rotated. Then rotate it 180 degrees to make it interchangeable, and immediately repeat the above operation.

The present invention uses the structure and operation detailed above to coat the core wire with flux, and the forming cylinder maintains an airtight structure during flux forming, and is press-formed after vacuum degassing to form a high-pressure film without air being mixed in. A flux having a certain density can be loaded into a flux cylinder, and the molded flux can be supplied for painting while being loaded into the flux cylinder.

That is, in order for wet-mixed flux in a loose state to become an ideal forming flux, the pressurized flux flows in the conical drawing part of the forming cylinder and becomes a dense forming flux.
The long cylindrical body of one cylinder of flux (e.g., 1 m in length, 50 to 60 kg of flux) that has passed through this constriction has a uniform density and does not contain any air, so it can be used as a coated welding rod without eccentricity. A high-quality welding rod with a uniform coating outer diameter can be coated.

The preferred angle θ of the constricted portion of the forming cylinder of the present invention is in the range of 50 to 90°. If the aperture angle exceeds 90°, the flow of the flux will become non-uniform, and there will be areas where the flow is delayed at corners, resulting in non-uniform density. On the other hand, when the angle is less than 50°, the distance of the conical drawing portion is long, and as a result, there is no flow effect due to only pressing, and there is also a large amount of residual flux, resulting in poor molding efficiency. In addition to this angle θ, the drawing ratio of the conical drawing part (cross-sectional area of the main part - cross-sectional area of the tip of the drawing part/cross-sectional area of the main part x 100) is preferably 60% or more.

As described in detail above, the coating coating apparatus of the present invention pressurizes flux under vacuum and draws it to form a long cylindrical shaped flux, which is immediately applied for coating. This method solves the various problems associated with molding fluxes and allows for extremely high efficiency and very good coating. In other words, there is no variation in the outer diameter of the welding rod, eccentricity, cracking of the coating, etc. that occur with conventional molded flux coating, and the appearance of the welding rod is beautiful, resulting in a high-quality welding rod that can be coated and improve yields. will also be greatly improved.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view showing a specific example of a conventional coating device, FIG. 2 is a plan view of FIG. 1, FIG. 3 is a plan view showing an embodiment of a coating device according to the present invention, and FIG. A, B, and C are cross-sectional views illustrating the operation of the device of the present invention. 23... Shoot, 24... Seal, 25...
Main part, 26... Conical throttle part, 28, 29... Flux cylinder, 30, 31... Flux cylinder holder, 32... Rotating shaft, 33, 33'...
...Air cylinder, 37...Forming presser piston, 3
9...Forming press cylinder, 41...Painting pressure cylinder, 42...Die head, 49...Vacuum degassing hole, 50...Air cutoff valve, 54...Forming cylinder, 56...Flux.

Claims (1)

[Claims] 1. In a coating material coating device, in which a pair of coating material cylinders are held interchangeably between two positions: a coating material forming position and a coating die head discharging a coated welding rod at the front, the coating material is At the molding position, a molding cylinder having a main part with an inner diameter larger than that of the coating cylinder, a conical drawing part, and a vacuum degassing hole is provided coaxially with the coating cylinder at a rear position, and a molding cylinder is provided at a rear position of the coating cylinder. A pressurizing cylinder is installed at the rear of the coating cylinder at the coating position, and a driving device for adjusting the longitudinal position is installed independently on each of the pair of coating cylinders. Features coating coating equipment for coated arc welding rods.