CN1626305A - Method for connecting hard metals through successive built up welding - Google Patents

Abstract

The present invention is a hard alloy continuous surfacing welding method and its device, which comprises a clamping box equipped with welding rods. The clamping box has an outlet in front and an inlet in the rear. When the previous welding rod melts to the tail, the system will send out a signal to drive the second welding rod to be sent out from the cartridge box, and to top the tail of the welding rod. After entering the argon chamber, the system will send out a signal to start an argon arc welding machine. The welding rod is ignited at the contact point. When the arc current reaches a certain value, the current is cut off due to the fusing short circuit, and the magnetic thruster pushes the welding rod up for the second time so that the previous welding rod and the next welding rod are melted at the head and tail to complete the welding, and then The magnetic thruster returns to the original state, and waits for the second automatic welding of the hard alloy electrode, so as to realize the automatic connection of the hard alloy electrode in the surfacing welding.

Description

Cemented carbide continuous surfacing welding connection method and device

technical field

The invention belongs to a hard alloy continuous surfacing welding connection method and its device, in particular to a welding rod connection technology and mechanism for hard alloy continuous surfacing welding.

Background technique

Overlay welding refers to depositing a wear-resistant layer on a carbon steel or bottom carbon steel substrate. A thin layer of corrosion-resistant metal that brings the worn working surface back to its original size. Doing so can have the advantages of prolonging the service life of workpieces or equipment, reducing production costs, improving labor productivity, and rationally utilizing materials. However, the surfacing welding technology is relatively difficult, and it requires pre-treatment of the workpiece in advance. For heat treatment and reprocessing after heat welding, it is especially required that the electrode and the substrate match during surfacing, so that the chemical composition and performance of the surfacing layer meet the predetermined requirements. At the same time, the high density, uniformity, and flatness of the joint surface between the surfacing layer and the substrate are required to reduce the processing hours of the subsequent process.

As we all know, the existing cemented carbide electrodes cannot be curled due to their brittle and hard materials; their toughness is poor, and the electrodes that can only be cut into a certain length cannot realize automatic continuous surfacing welding during operation and can only be operated manually. Surfacing operation, it is difficult to meet the above-mentioned technical requirements such as good compactness between the surfacing layer and the substrate, uniform surfacing layer, and flatness. Some workpieces, such as the surfacing welding on the surface of large rollers, must adopt automatic surfacing welding process. In order to meet the technical requirements of automatic surfacing welding, only flexible welding wire with unlimited length can be used as welding rod. The hardness of this flexible welding rod; The level will be greatly reduced, which is very different from the performance of the welding layer using hard alloy electrodes for overlay welding. Therefore, it is of great practical significance and remarkable economic benefit to invent a technology and mechanism that can realize automatic continuous surfacing welding by using a hard alloy electrode with limited length.

Contents of the invention

The purpose of the present invention is to propose a special mechanism, which can realize automatic continuous surfacing welding even with hard alloy electrodes, so as to meet the requirements of workpieces that can only meet the technical requirements with alloy electrodes, and can realize automatic continuous surfacing welding.

The cemented carbide automatic surfacing welding device of the present invention at least includes an electrode clamping box, a signal sensor, a magnetic thruster, a welding rod clamping transmission mechanism, an argon chamber and an external argon arc welding machine to connect two cemented carbide electrodes Automatically connect, so as to ensure the continuous and smooth progress of the carbide welding rod in the automatic surfacing welding.

There is an outlet in the front of the welding rod cartridge and an inlet in the back, in which several welding rods are housed. The cartridge is fixed on the plate, when the previous electrode melts to the end, a signal will be sent out, so that the second electrode will be sent out from the cartridge, and the end of the electrode will be topped, and after entering the argon chamber, a signal will be sent to start a second electrode. An argon arc welding machine ignites the electrode and the contact point. When the arc current reaches a certain value, the current is cut off due to the fusing short circuit, and the magnetic thruster pushes the electrode up for the second time so that the previous electrode and the next electrode are at the beginning and end. The welding is completed in the molten state, and then the magnetic thruster returns to the original state, waiting for the second automatic welding of the hard alloy electrode.

The second object of the present invention is to propose a continuous surfacing welding connection method for cemented carbide.

The method is to place several welding rods in the welding rod clamping box, the clamping box is fixed on the flat plate, there is an outlet in the front, and an inlet in the rear, when the previous welding rod melts to the tail, a signal will be sent to make the second welding rod go out of the clamping box. It is sent out from the box, and the tail of the welding rod is topped. After entering the argon chamber, a signal is sent to start an argon arc welding machine to ignite the welding rod and the contact point. When the arc current reaches a certain value, it is cut off due to the fusing short circuit. Current, the magnetic thruster pushes the electrode up for the second time so that the previous electrode and the next electrode are melted at the beginning and end to complete the welding, and then the magnetic thruster returns to the original state, waiting for the second automatic welding of the carbide electrode.

Description of drawings

Fig. 1. Mechanism schematic diagram of the present invention

Fig. 2. The electrical principle diagram of signal sensor in the present invention

Example

Below in conjunction with accompanying drawing, the present invention will be further described:

With reference to accompanying drawing 1, workpiece 30, welding torch 50, three major elements when tungsten carbide electrode 40 is overlay welding, welding torch 50 is fixed on the flat plate 70 by fixed chuck 60, welding rod 40 is clamped by passive clamping wheel 80, passive clamping wheel The tightness of the compression spring 90 and the compression nut 10 are adjusted. The active clamping wheel 2 and the passive clamping wheel 8 form the welding rod clamping and conveying mechanism. The active clamping wheel 20 is driven by the driving motor 10, as long as the welding torch 50 is adjusted to a certain angle Give start, rotate workpiece 30 with another group of machinery, start welding rod by drive motor 10 and send into clamping wheel, and build-up welding just carries out smoothly. The problem is that if the connection between the front and rear electrodes is not resolved, then the surfacing welding can only be carried out in gaps. To carry out automatic surfacing welding, it becomes the technical key to solve the smooth connection between the front and rear electrodes.

First a large amount of welding rod is packed in the clip box 18 as bullet clip, and the shape of this clip box 18 can be flat shape, also can be triangular shape. There is front block 14 at the front end of clip box 18, and a welding rod outlet 22 is arranged below, and a welding rod inlet 24 is arranged on the rear top of clip box 18, and the outside of the bottom is connected with magnetic thruster 21, and a block 19 is also arranged at the rear end of clip box 18, front and rear The function of the block is to make the welding rods be arranged naturally and orderly in the box, and the box 18 is connected with the flat plate 70, and the two are insulated and separated by the insulating plate 15. Driven by the stepping motor 10, the active clamping wheel 20 can rotate according to the required angle, but cannot move up and down. Compression spring 90 is realized, and the outlet of cartridge 18 is connected with argon chamber 12 again, and argon enters argon chamber 12 by argon hole 11 and connects an argon arc welding machine (not shown).

The specific working steps are described as follows:

When the electrode 40 being welded runs normally to the outlet of the contact tip 13, the signal sensor acts, the electrode 40 is disconnected from the entire electrode holder 18, 1 and 2 in Fig. 2 are disconnected, and a signal is sent, and the relay J2 starts Work. Make the time relay J1 also start counting, send a signal to make the magnetic thruster start and be used to connect the electrode 16 to push out the electrode holder 18, and withstand the electrode tail being welded, enter in the argon gas 12 together, cut off simultaneously on the Fig. 2 The 5; 6 connection also cuts off the connection between the 5'; 6' two points. Make the J4 relay work, the J4 normally open contact is closed, that is, the current of the external argon arc welding machine is closed, and the magnetic thruster 21 stops advancing at this time, so that there is a gap between the welding rod 4 and the head and tail of the welding rod 16, which is conducive to The high-frequency arc ignition input high-frequency pulse signal is sent from 11 to argon gas to ignite the arc, so that the front and rear electrodes 40 generate an arc between the ends of 16, and when the current measured by the current relay reaches a certain value, the ends of the electrodes are melted and short-circuited. Immediately send a signal to make the magnetic thruster 21 start for the second time, and the second welding rod 16 is pushed up to join with the previous welding rod 4 tails again, so that the two welding rods in the melting state are connected end to end. At this moment, the welding rod 4 continues to be sent into the molten pool between the welding torch 50 and the workpiece 30 under the action of the active clamping wheel 20 and the passive clamping wheel 80, and the two points 7 and 8 on the electrical control schematic diagram (shown in Figure 2) are closed simultaneously. , so that the relay J6 starts working. The time relay J2 is set to 2 seconds in advance, and when the time is up, the power supply is cut off immediately, and everything is restored to the original state, waiting for the automatic welding of the two electrodes before and after the second time.

Compared with the prior art, the present invention has the following obvious advantages:

1. Connect the hard alloy surfacing electrodes with limited length into infinitely long electrodes. Solve a key difficulty for any electrode can be transferred to automatic welding. And because be a welding rod will carry out the connection of the second root again when running out. So the organization is not big.

2. The shape of the connecting joint is smooth and not protruding, and it will not be caught in the clamping wheel during automatic welding and cannot move.

3. Due to the use of butt joints, the material is squeezed and is not prone to cracks.

4. Because the current and the amount of collision are controlled, and the time is extremely short, the influence on the alloy composition of the welding material can be ignored.

Claims (6)

1. A tungsten carbide continuous overlay welding device, comprising at least an argon chamber and an externally connected argon arc welding machine, is characterized in that it also includes an electrode cartridge 18, a magnetic thruster 21, a signal sensor, and an electrode clamp delivery mechanism. 2. The cemented carbide continuous surfacing device according to claim 1, characterized in that the front end of the clamp box 18 has a front stopper 14, a welding rod outlet 22 is located below, and a welding rod inlet 24 is located at the rear and upper part of the clamp box , the outside of the bottom is connected with the magnetic thruster 21, and there is a block 19 at the rear end of the box. The function of the front and rear blocks is to make the welding rods be arranged naturally and orderly in the box. The box 18 is connected with the hanging plate 7, and an insulating plate is used between the two 15 insulation separated. 3. The tungsten carbide continuous surfacing device according to claim 1 or 2, characterized in that the shape of the clip box 18 can be flat like self-clamping, or triangular. 4. The cemented carbide continuous surfacing device according to claim 1 or 2, characterized in that the clamping and conveying mechanism is composed of driving clamping wheels 20 and passive clamping wheels 80 . 5. The cemented carbide continuous surfacing device according to claim 4, characterized in that a compression spring 90 is set on the passive clamping wheel 8 and is controlled by a torsion screw 10. 6. A continuous surfacing welding connection method for hard alloys, including a system composed of an electrode holder, a signal sensor, a magnetic thruster, an electrode clamping transmission mechanism, an argon chamber and an external argon arc welding machine, its characteristics The reason is that a number of welding rods are placed in the welding rod cartridge, and the cartridge is fixed on the plate. There is an outlet in the front and an inlet in the rear. When the previous welding rod melts to the tail, a signal will be sent to make the second welding rod be sent out from the clamping box. And top the tail of the electrode, after entering the argon chamber, send a signal to start an argon arc welding machine, so that the electrode and the contact point are ignited. When the arc current reaches a certain value, the current is cut off due to the fusing short circuit, and the magnetic thrust The pusher pushes the electrode up for the second time so that the last electrode and the next electrode are melted at the head and tail to complete the welding, and then the magnetic thruster returns to the original state, waiting for the second automatic welding of the hard alloy electrode.

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