JP3098007B1 - Sensor mounting bracket for welding torch - Google Patents

Abstract

The present invention provides a simple sensor mounting bracket that effectively cools and protects a sensor without circulating a cooling medium through a sensor and a protective housing attached to a welding torch. SOLUTION: A grip portion 11 to be attached to a side wall of a water-cooled welding torch 3, a support surface 16 for mounting and fixing a sensor 2, and a light shielding plate 13 for blocking radiation emitted from a welding portion 31 to the sensor.
The support surface 16 is formed of a substantially heat conductive material, the support surface 16 supports the sensor through an insulating material 14 having electrical insulation, and the grip portion 11 thermally connects the welding torch 3 to the welding torch 3. It is formed so that it can adhere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sensor support device for attaching a sensor to a welding torch, and more particularly to a sensor mounting bracket for cooling and protecting a sensor attached to a water-cooled welding torch.

[0002]

2. Description of the Related Art Although the development of automatic welding equipment using a welding robot has been remarkable, in order to respond to more advanced demands such as high-speed and precise welding, and high-quality welding even for complicated welding lines, There is an increasing demand for measuring and observing the welded portion and the periphery of the welded portion as close as possible, and it is becoming increasingly necessary to fix and use a precision measuring instrument such as a visual sensor or a contact sensor near the welding torch. However, when the precision measuring device is installed near the welding torch, there is a fear that not only the measurement accuracy is reduced due to the failure due to the high heat generated by welding, but also the failure occurs.

For this reason, conventionally, for example, as shown in FIG.
Prepare a special measuring instrument that contains the sensors in a protective housing and form a cooling water channel inside, fix this measuring instrument to the welding torch, and circulate a cooling medium such as cooling water or cooling gas through the measuring instrument itself. Heat removal methods have been used. FIG. 2 is a block diagram showing a configuration example of a conventionally used sensor mounting portion. In the method illustrated here, the measuring instrument is installed close to the welding torch by attaching the mounting bracket to which the measuring instrument is fixed to the welding torch.

A circulation path is formed inside the measuring instrument, and coolant is supplied from an inlet, circulates through the inside, takes heat, and is discharged from an outlet. A light-shielding plate is attached to the distal end of the measuring instrument via a mounting table to prevent radiation from the arc light from entering the measuring instrument. The mount supports and fixes a transparent plate that covers and protects the detection port of the measuring instrument. The transparent plate is formed of an acrylic plate or the like that transmits light rays for measurement. The mounting bracket is formed of a material having good electrical insulation such as epoxy resin, and also has a function of insulating the measuring instrument from welding current.

The radiant heat received by the light-shielding plate from the arc is radiated to the surroundings or transferred to a cooling medium and discharged, so that the temperature of the measuring instrument does not rise. Further, the light shielding plate is provided with a purge port. Purge air is supplied from the back of the measuring instrument, cools the surroundings via the measuring instrument and the mounting table, and finally blows out from the purge port in parallel with the detecting port of the measuring instrument to prevent fumes from adhering to the transparent plate.

Since the measuring instrument is a precision electric device, it is not preferable to use a good electric conductor such as water as a coolant since a leak may cause a serious trouble accident. Therefore, insulating oil or cooling air is usually used as a coolant. When using insulating oil, the operating cost increases, and when using air, a sufficient cooling effect tends to be hardly obtained. In fact, it is difficult to apply to welding work having a large heat load such as lamination welding.

[0007] Further, when cooling by a medium is used, a dedicated measuring instrument must be manufactured, and the structure of the measuring instrument becomes complicated and large, and the equipment cost rises, for example, a cooling device dedicated to a sensor is required. . Furthermore, handling of the cooling medium causes operational difficulties. If the cooling water leaks, the insulation of the measuring instrument will deteriorate, and maintenance will be troublesome. It is to be noted that a method is also used in which the sensor is housed in a large-sized housing to increase the heat capacity to increase heat dissipation, or a double wall of the sensor itself is provided with a heat insulating function to suppress the temperature rise. However, any of these methods has a problem in that the structure of the measuring instrument is complicated, which leads to an increase in cost, and that the measuring instrument becomes large and difficult to mount on a welding torch.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sensor for cooling and effectively protecting a sensor without circulating a cooling medium through a sensor attached to a welding torch and a protective housing. It is to provide a mounting bracket. Another object of the present invention is to make it possible to directly use an ordinary sensor instead of a special heat-resistant structure manufactured for monitoring a welding state.

[0009]

In order to solve the above-mentioned problems, a sensor mounting bracket according to the present invention is used by being mounted on a water-cooled welding torch, and has a grip portion mounted on a side wall of the welding torch and a sensor. A heat-insulating material that includes a support portion to be fixed and a light-shielding plate that blocks radiation emitted from the welded portion to the sensor, and is substantially formed of a heat-conductive material, and has electrical insulation between the support portion and the sensor. And a grip portion is formed so as to be in thermal contact with the welding torch. Further, an air introduction nozzle may be provided in the support portion of the sensor mounting bracket, and an air circulation path may be formed inside the nozzle so that air is ejected to the front surface of the sensor.

Particularly, in arc welding, the main cause of the rise in the temperature of the sensor is direct radiant heat from the arc. Unless the temperature in the welding environment is particularly high, the amount of heat transferred from the surrounding atmosphere to the sensor is not a problematic quantity compared to the amount of radiation received from the arc light. Therefore, it is important to prevent the arc light from directly irradiating the sensor in order to effectively prevent the temperature rise of the sensor. In addition, a large welding torch used in an automatic welding machine uses cooling water to prevent temperature rise in order to protect against heat generated during welding. Cooling water is passed through a circulation path provided inside the torch portion, for example, to cool to about 200 ° C. at the tip of the torch and to about 60 ° C. for the torch body.

The present invention focuses on the fact that the welding torch is strongly cooled by cooling water, and uses a water-cooled welding torch as a cold heat source instead of providing the measuring device with a cooling function. It is. The sensor mounting bracket of the present invention has the light shielding plate, so that light from the welding arc does not reach the set sensor, and since the bracket is formed of a heat conductive material, heat injected into the light shielding plate passes through the bracket. Since the cooling torch escapes to the torch, the temperature of the bracket is restricted by the temperature of the torch body, so that it is possible to suppress an increase in the temperature of the attached sensor.

By using a heat-insulating material for the sensor support surface, even if the temperature of the sensor mounting bracket rises somewhat, heat transfer to the sensor is suppressed, so that the sensor does not overheat and maintains measurement accuracy. be able to. Further, a large current is applied to the welding torch, and electric noise is generated as an arc is formed. Therefore, if the sensor mounting bracket is formed of a material such as a metal having good heat conductivity and good conductivity, it will have a significant effect on the measurement accuracy of the measuring instrument. Therefore, it is preferable to maintain the measurement accuracy by forming the sensor support surface with an electrically insulating material and blocking the influence on the measuring instrument.

In the conventional sensor mounting method, since heat is removed by introducing a cooling liquid or cooling air into the sensor housing or the protective housing, a medium passage is formed in the sensor main body or the housing, a cooling medium pipe to the sensor, and a medium. Prevention of leakage, treatment at the time of leakage,
Although the operation of the cooling device and the like could not avoid the complexity of the structure of the device itself and the increase in operational difficulties, these problems could be solved by using the sensor mounting bracket of the present invention. . Also, if the sensor is mounted on the sensor mounting bracket of the present invention, the sensor can be maintained at a normal operating temperature, so that the sensor and a measuring instrument incorporating the sensor are not special and inexpensive with measures against high temperatures. Inexpensive and highly reliable products commonly used can be used. In the case where the air introduction nozzle and the air circulation path are formed in the support portion of the sensor mounting bracket to allow the purge air to pass through, the cooling function is achieved by the low temperature air flowing inside the bracket in addition to the cooling by the heat transfer of the bracket. And by purging the front surface of the sensor with air, it is possible to prevent welding spatter or the like from adhering to lower the sensor function.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments with reference to the drawings. FIG. 1 is a side view showing a mounted state of the sensor mounting bracket of the present embodiment.
The sensor mounting bracket 1 according to the present embodiment has a measuring device 2 mounted thereon and fixed to a welding torch 3 so that a very close vicinity of a welded portion can be measured. The measuring device 2 may be an optical measuring device such as a one-dimensional laser sensor for distance measurement, a two-dimensional laser sensor for area measurement, or a CCD camera for monitoring a welded portion.

The sensor mounting bracket 1 comprises a grip 11, a bridge 12, a light shielding plate 13, a sensor pad 14, and a seal sheet 15. The grip portion 11 fixes the sensor mounting bracket 1 to the welding torch 3 by sandwiching the body of the welding torch 3. The bridge 12 has an L-shaped cross section, connects the grip 11 and the light shielding plate 13, and forms a mounting surface 16 for stopping the measuring instrument 2 inside the side where the grip 11 is provided. The grip 11 and the bridge 12 are formed of an aluminum alloy having good heat conductivity. A purge air circulation path is provided inside the bridge 12, and purge air introduced from a supply nozzle 18 provided at the upper end cools the bridge 12 through the circulation path, and is opened from the base of the light shielding plate 13. 17 is spouted out.

The light shielding plate 13 is attached to the outside of the other side of the bridge 12. An opening 17 is provided in a portion corresponding to a position corresponding to the observation port of the measuring instrument 2 attached to the attachment surface 16. The opening 17 penetrates through the bridge 12, the light shielding plate 13, and the seal sheet 15, but is formed as small as possible without interfering with the measurement. Opening 1
An acrylic transparent plate (not shown) is provided inside 7 to protect the optical system of the measuring instrument. The light shielding plate 13 is provided with a retaining wall of an appropriate height on the side of the welding torch 3, and the light from the arc 31 formed by the welding torch 3 is disposed in the depth of the opening 17. No more than two shots. The light shielding plate 13 is formed of a material such as chromium copper to which welding spatter is unlikely to adhere.

The measuring instrument 2 is fixed to a mounting surface 16 via a sensor pad 14. The sensor backing plate 14 is formed of a material that insulates heat and electricity, such as ceramics and epoxy resin. In addition, the outer wall of the measuring instrument 2 has a double structure, and the purge air introduced from the purge air supply port 21 flows through the space of the outer wall, and then passes through a hole provided in the bridge 12 to open a hole from the base of the light shielding plate 13. 17 may be configured to be ejected to the front surface. The seal sheet 15 is formed of an epoxy resin plate or the like, and prevents air leakage and cuts off heat conduction from the bridge 12.

The measuring instrument 2 receives a driving power supply via a cable connected to the socket 22, and outputs a measurement signal. The welding torch 3 is a large water-cooled torch. Cooling water is supplied from a supply port 32, circulates to the tip of the torch, and returns from a discharge port 33 to a cooling device (not shown). With this cooling system, for example, even when the welding current is 300 A and the apparatus is operated for 20 minutes, the torch tip temperature can be suppressed to 200 ° C. and the surface temperature of the torch body can be suppressed to about 60 ° C. The holding portion 11 contacts the wall of the cooled torch body on a wide surface and is in close contact in a thermal sense.

When the measuring instrument 2 is mounted on the welding torch 3 using the sensor mounting bracket 1 of the present embodiment, the radiation from the arc 31 generated at the tip of the welding torch is blocked by the light shielding plate 13, so that the measuring instrument 2 is not directly heated. . Further, the radiant heat received by the light shielding plate 13 is conducted through the bridge 12 having good thermal conductivity and flows out to the cooled welding torch 3 via the holding portion 11, so that the sensor mounting bracket 1 including the light shielding plate 13 has a high temperature. Never be. Furthermore, since the measuring device 2 is mounted on the mounting surface 16 of the bridge 12 via the sensor abutting plate 14 having good heat insulating properties, heating by heat transfer is small.

Conventionally, the measuring instrument has been insulated from the welding current by using an insulating bracket. However, in the sensor mounting bracket 1 of the present invention, welding is performed by using a material having high insulation performance for the sensor backing plate 14. Eliminates the effects of current. The sensor mounting bracket 1 of the present embodiment uses the water-cooled welding torch 3 as a cold heat source to cool the sensor without using a special cooling device or cooling mechanism, thereby achieving accurate measurement and extending the life of the measuring instrument. can do. In addition, since the cooling medium is not recirculated inside the sensor, the structure of the sensor can be simplified, and a normal-type instrument can be used with a simple modification. Furthermore, since a conductive liquid such as water is not used, there is no need to worry about a decrease in insulation due to leakage.

[0021]

As described above, by using the sensor mounting bracket of the present invention, the measuring device can be cooled and the welded portion can be accurately measured without providing a special utility device for cooling the sensor. be able to.
Further, there is no need to use a special-purpose welding measuring instrument having a special structure for enhancing the cooling function, and the intended measurement can be performed using a low-cost and high-accuracy ordinary measuring instrument. Also, unlike the water-cooled type, there is no fear of insulation deterioration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an application example of a sensor mounting bracket according to the present invention.

FIG. 2 is a block diagram showing an example of a conventional sensor mounting bracket.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sensor mounting bracket 11 gripping portion 12 bridge 13 light shielding plate 14 sensor backing plate 15 seal sheet 16 mounting surface 17 opening 18 purge air supply port 2 measuring instrument 21 purge air supply port 22 socket 3 welding torch 31 arc 32 cooling water supply port 33 cooling Water outlet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI G12B 15/00 G12B 15/00 (56) References JP-A-8-309556 (JP, A) JP-A-9-141433 (JP) JP-A-53-52260 (JP, A) JP-A-7-80645 (JP, A) JP-A-8-132235 (JP, A) JP-A-2-299779 (JP, A) 2-15880 (JP, A) Japanese Utility Model 63-118516 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 9/095 B23K 9/29 B23K 9/32 B23K 31 / 00 G12B 9/08 G12B 15/00

Claims (2)

(57) [Claims] [Claim 1 further comprising a grip portion and a sensor attached to the side wall of the water-cooled welding torch from the support portion and the welding portion to be mounted integrally fixed to the light shielding plate for shielding the radiation irradiating to the sensor, the support portion is the said gripping portion Connect the light shield plate and the sensor
It is one that supports with other in contact with the sensor through the thermally insulating material with electrical insulating properties is formed in a substantially thermally conductive material, gripping portions substantially thermally conductive material
It is formed so as to be in close contact with the welding torch, and is characterized by flowing heat from the welding portion using the water-cooled welding torch as a cold heat source to suppress a rise in temperature. Sensor mounting bracket. 2. The sensor according to claim 1, wherein an air introduction nozzle is provided in the support portion, and an air flow path is formed inside the support portion so that air is ejected to the front surface of the sensor. Sensor mounting bracket.