JPS5950425B2 - Waterproof underwater stud welding gun - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a waterproof underwater stud welding gun, and is intended to improve and put into practical use the invention of the same name disclosed in Japanese Patent Application Laid-Open No. 55-33877, which was previously developed by one of the inventors.

The main features are that the gun body for normal stud welding that uses a ferrule is housed in a waterproof housing, that compressed gas is put in the housing, and that the gun body side bearing of the operating shaft that attaches the stud to the tip has elasticity. This includes the provision of a seal section. Compressed gas leaks out of the elastic seal when the internal pressure of the housing exceeds the external pressure, and by keeping the internal pressure of the housing almost in balance with the external pressure at all times, the movement of the operating shaft in and out is affected by the difference in internal and external pressure. In addition, gas is allowed to leak from the seal portion to facilitate sliding of the operating shaft sliding portion, and to prevent welding spatter from entering and adhering to the operating shaft sliding portion. In addition, as a second invention, in order to wipe away moisture on the stud tip and the surface of the base material and dry it,
The entire amount of compressed gas in the ferrule holding part is injected at high pressure from the gap between the stud and the ferrule without escaping elsewhere.

The above-mentioned invention of JP-A No. 55-33877 removes moisture from the welded part, which is the most problematic issue in underwater stud welding, by sending compressed gas into the outer cylinder surrounding the outer circumference of the stud, and the compressed gas removes the water inside the outer cylinder. This is the basic invention that solved the problem for the first time by a method in which moisture is removed and at the same time is ejected from the gap between the stud and ferrule to wipe away the moisture on the tip of the stud and the surface of the base material.

However, in practice, the following problems arose.

In other words, the issue of making the gun body itself water-resistant can be solved by impregnating it with resin, etc., but with studs attached, water and impurities can enter the sliding parts of the operating shaft and bearing that go in and out of the gun body, causing dielectric breakdown. There remained a difficult problem in implementation, such as welding spatters becoming stuck and obstructing the movement in and out. Also, even if the compressed gas sent to eliminate the water in the outer cylinder is ejected from the gap between the stud and ferrule,
The ferrule holding part that holds the ferrule in its mouth usually has two to four vertical grooves cut in it to provide a spring action in order to securely hold the ferrule in place. It was easy for defects to appear.

As mentioned above, this invention eliminates the initial problem by using the waterproof housing of the gun body and the elastic seal part of the operating shaft bearing, and sends high-pressure gas that does not escape to the gap between the stud and ferrule, thereby solving the later problems. I lost it.

Next, the configuration and embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of one embodiment of this invention, and its main components are: a gun body 1 for stud welding using a ferrule 14; A waterproof housing 2 with a cylindrical portion 6 attached thereto, a funirule holding portion 10 provided inside the cylindrical portion 6, an operating shaft 3 with a stud gripping fitting 23 attached to the tip, and an operating shaft 3 that moves in and out of the gun body 1 by an arter length; Gun body side bearing 30
The elastic seal portion 4 provided in the housing 2, the air supply pipe 29 for sending compressed air into the housing cylindrical portion 6, and the like.

Since the gun body 1 is housed in the waterproof housing 2, it can be used as is for normal use on land.

In this case, the inside of the cylindrical part 6 attached to the front part of the housing 2 is divided into front and rear parts by an intermediate wall 31 having a ferrule holding part 10, and communicated through a through hole 32 (see FIG. 3). The rear part of the cylindrical part 6 is hard like the housing 2, but the front part 16 in contact with the base material M is made of a permeable material, such as steel wool or sponge, into a cylindrical shape, which fragments the gas pushed into the water and creates small bubbles. It has the effect of releasing it. If you make large bubbles and put them out, water will seep in the moment they come out, so make them into small bubbles. As shown in FIG. 2, since the ferrule 14 is normally stepped, the inner cylinder 9 with a vertical slit of the ferrule holding part 10 is held in the upper part of the ferrule 14, and the outer cylinder 10a without a vertical slit is placed in the lower part of the ferrule. This prevents the compressed gas from escaping.

That is, the ferrule holding part 10 is attached to the center hole of the intermediate wall 31, and in this embodiment, an outer cylinder 10a with a flange attached to the front surface of the intermediate wall 31, and an elastic clamping body (with a flange attached to the rear surface).
The inner cylinder (9) with vertical slits cut into the cylinder forms a double-structured ferrule support cylinder, as shown in Fig. 2.
The upper end protrusion of the ferrule 14 is held between the clamping bodies 9,
Outer cylinder 10a with no vertical grooves on the outer peripheral surface of the lower ferrule
The ends are tucked in. A compressed gas introduction path 8 provided in the intermediate wall 31 communicates with the ferrule holding portion 10, and receives compressed gas that is not depressurized from the air supply pipe 29 via a branch pipe 27 and a valve 7. As mentioned above, the high pressure gas is ejected from the gap between the stud 15 and the ferrule 14 to blow away the moisture in the weld area and then dry it. The compressed gas is preferably a dry gas, and may be air, carbon dioxide gas, or argon gas. The operating shaft 3 that enters and exits from the gun body 1 is the same as the known one.

A well-known stud gripping metal fitting 23 is fitted to this tip, and a welding current is sent to this, and during energization, it is pulled back into the gun body 1 by the arc length by magnetic force, and when energization is finished, it is returned by a spring. At that time, it is also well known that the ends of the studs and the fused portions of the base material surface are crimped together. As the elastic seal portion 4 of the gun body 1 side bearing 30 that prevents the lateral vibration of the operating shaft 3,
In this embodiment, a lip seal 4 is fixed with a retaining ring 24 as shown in FIG.

As is well known, when the external pressure is high, the lip seal 4 is pressed against the shaft 3 to strengthen the sealing action, and when the internal pressure is high, the lip seal 4 weakens the sealing action and allows the gas inside the housing to leak. Air pipe 2
A needle regulating valve 5 is interposed between 9 and the housing 2, and the original pressure on the water is appropriately reduced and fed.

The adjustment of the regulating valve 5 is carried out by an underwater worker, and it can be seen that if the pressure inside the housing 2 is lower than the water pressure, no gas leaks from the elastic seal portion 4, and if it is higher, leakage occurs and bubbles are produced. In this example, the water in the cylinder 6 is removed by the leaked gas, and no special gas receiving mark for water removal is provided. A tripod 3 is attached to the outer periphery of the intermediate wall 31 of the cylindrical portion 6 to which the ferrule holding portion 10 is attached.
3, 33, and 33a come out, and each support bolt 13 is attached to the base material M.
It is oriented perpendicular to.

The protrusion length of each bolt 13 can be adjusted using a nut. Next, a supplementary explanation of the details and the operation of this embodiment will be given.

FIG. 1 shows the state before the gun is pressed against the base material M, and the stud bolt fitted into the gripper fitting 23. The ferrule 15 protrudes slightly in front of the ferrule 14 fitted into the ferrule holding portion 10. Adjust the protruding length of the tripod bolt 13 appropriately, then hold the grip of the gun housing 2 and tighten the stud 15.
When the tip is pressed against the base material M, the stud 15 and the gripper 23 compress the spring in the main body 1 and move back a little, making them electrically conductive with the base material M. The gas leaked from the elastic seal part 4 is filled into the cylindrical part 6 by the regulating valve 5 which has already been adjusted to open, and water is removed.

In the horizontal position shown in FIG. 1, water is pushed out through the hole 12 opened at the lower part of the intermediate wall 31 and the front part 16 of the breathable cylinder, and then the pushed out leaked gas forms bubbles and comes out. In the case of the downward position, the hole 11 at the bottom of the cylinder part 6 and the hole 12 at the bottom of the intermediate wall 31
Most of the water flows out through the front part 16 of the cylinder because a blind plug is placed in the cylinder. 2. In case of upward posture, hole 1 at the bottom of intermediate wall 31
In order to put a blind stopper only in 2, it comes out through the hole 11 on the lower side of the cylindrical part 6 and the front part 16 of the cylindrical part.

Unlike the above-mentioned basic invention, this invention eliminates the water in the cylindrical part 6, blows away the moisture near the welded part, and dries it. is different. Therefore, the flow rate (flow rate) of gas leaking from the seal portion 4 only needs to be small enough to prevent water from flowing back in the front portion 16 of the cylinder portion.

As a rough guide, it is sufficient that the bubbles come out without interruption through either the hole 12 at the bottom of the intermediate wall 31 or the hole 11 at the bottom of the cylindrical part J6.

Immediately before the start of welding, the cap 7 of the air supply branch pipe 27 is opened for a short time for 5 seconds, and the compressed gas at the original pressure is directly introduced into the ferrule holding part 1.0 through the gas introduction path 8 in the intermediate wall 31.

The high-pressure gas moves inside the outer cylinder 10a of the ferrule holding cylinder along the studs 15 and is ejected from the gap between the ferrules 14, blowing away moisture remaining on the tips of the studs 15 and the surface of the base material M, and drying them. In this case, if there is only an inner cylinder that holds the upper part of the ferrule, since the inner cylinder 9 has a vertical slit, the compressed gas escapes from this and may not pass between the ferrule and the stud.

In order to prevent this, concentrate the entire amount of compressed air in the gap between the ferrule and the studs, and ensure the blow drying effect, an outer cylinder 10a without a vertical slit is provided to hold the lower part of the ferrule. This compressed air is supplied to the front part 16 of the cylinder part
Go inside, then go outside into the water. When the waterproof start switch 18 is turned on, the welding current cord 2 connected to the housing 2 via the waterproof connectors 21 and 22
0, the stud 15, the base material M by the control current code 19
During this period, a short circuit current initially flows, and after the stud 15 is pulled up for a certain period of time to generate an arc, stud welding is completed by a well-known mechanism in which the stud 15 is pressed against the molten surface of the base metal by a spring.

In this example, since the valve 7 of the branch pipe 27 is closed, the pressure of the compressed gas to be injected is adjusted by the original pressure, and is approximately 7 kg/Cm2, which dries the surface moisture after water has been removed. let

Adjustment of the tripod bolt 13 is a well-known technique, so the explanation is omitted, but the point is to make the stud 15 stand at right angles to the base material M, and any support legs may be used. .

The method of fixing the gun body 1 and the housing 2 is left to the designer, but as shown in Fig. 4, the front part of the housing 2 is attached to the front part of the main body 1 through an airtight seal (O-ring) 25 with a screw 34 with a sealing pad 35. Recommend tightening.

The drain holes 11 and 12 may also be made into valves that can be opened and closed. In addition, the embodiments of the present invention may be varied and applied in various ways according to the well-known skills of the designer without changing the gist of the invention.

This invention is a gun for underwater stud welding, and by housing the gun body in a waterproof housing, the gun body for land use can be used as is.

Further, by providing an elastic seal portion that acts as a non-return seal on the operating shaft that protrudes from the main body or housing to the outside, a great effect has been produced. In other words, if the internal pressure of the housing is lower than the water pressure, water intrusion is stopped, and if the internal pressure is raised higher than the external pressure using the regulating valve, the seal part acts as a safety valve to maintain a minute pressure difference between the inside and outside of the housing, thereby preventing interference with the movement of the operating shaft due to the pressure difference between the inside and outside of the housing. What is important is that the gas leaking outward from the elastic seal reduces the friction between the bearing sliding surface and the operating shaft, and the airflow leaking from the elastic seal prevents welding spatter from adhering. In addition, there is no need for a troublesome automatic adjustment mechanism to adjust the regulating valve that sends compressed gas to the housing according to the water depth, and the operator can easily adjust the amount of air bubbles leaking from the seal by hand. Furthermore, in the second invention, the compressed gas jetted out from the gap between the ferrule and the studs is of high pressure and is directly introduced into the ferrule support tube, resulting in a strong moisture removal effect.During the jetting, the ferrule is in contact with the base material. There is no risk of it being blown away.

In this way, we achieved lightness in the movement of the actuating shaft, increased impact force during crimping, and complete removal of moisture from the weld.When we examined the cross-section of the weld in the underwater test of the above-mentioned example gun by polishing and corroding it, we found that: Excellent results, comparable to those obtained on land, were obtained. This invention has demonstrated the superiority of the principle of the above-mentioned basic invention, and has a great technical effect in that it has made it possible for inexperienced underwater workers to carry out underwater welding widely by improving its durability and welding quality.

[Brief explanation of drawings]

FIG. 1 is an explanatory cross-sectional view of one embodiment of this invention, FIG. 2 is an enlarged cross-sectional view of the tip thereof, FIG. 3 is a bottom view thereof, and FIG. 4 is an explanatory cross-sectional view of the vicinity of the elastic seal portion. 1...Gun body, 2...Waterproof housing, 3...Operating shaft, 4...Elastic seal portion, 27, 29... Air pipe, 10...
Ferrule support part.

Claims (1)

[Claims] 1. A stud welding gun body using a ferrule;
The gun body includes a waterproof housing that airtightly encloses the outer periphery of the main body except for the front part, and has a cylindrical part surrounding the stud in the front part, a ferrule holding part provided in the cylindrical part, and a stud gripping fitting attached to the tip. It is equipped with an operating shaft that moves in and out by an arc length, an elastic seal part provided on the gun body side of this operating shaft, and an air supply pipe that sends compressed gas into the housing, and when the internal pressure of the housing is higher than the surrounding water pressure, A waterproof underwater stud welding gun, characterized in that compressed gas leaks from the elastic seal portion at a flow rate suitable for reducing friction. 2 A stud welding gun body that uses a ferrule,
The gun body includes a waterproof housing that airtightly encloses the outer periphery of the main body except for the front part, and has a cylindrical part surrounding the stud in the front part, a ferrule holding part provided in the cylindrical part, and a stud gripping fitting attached to the tip. An operating shaft that moves in and out by an arc length from the ferrule, an elastic seal provided on the gun body side of the operating shaft that loosens due to internal pressure, and an air supply path that sends compressed gas into the housing and into the ferrule holding section A waterproof underwater stud welding gun characterized by a mechanism in which almost all of the high-pressure compressed gas sent to the holding part is ejected from the ferrule and the gap between the studs, thereby drying the moisture on the stud tips and the base metal surface. .