JPH03210973A - Electric connector - Google Patents

Abstract

PURPOSE: To provide an electrical connector for a robot welding machine for carrying out resistance welding work in particular by effectively sealing electrical contacts with each other and evading the short-circuit by the leakage of water. CONSTITUTION: The electrical connector 30 for the robot welding machine includes a pair of electrical connectors 35, 60. One 35 of their contacts delineates a tubular socket 37 and another contact 60 delineates a pin 62 to be shrinkage fitted into a socket 37. The respective contact 35, 60 are provided with connectors 39, 41; 66, 67 for connection to conductors 40, 65. The respective portions of the contacts or the like are sealed into respective housings 36, 61 made of an insulating material. When the pin 62 engages the inside of the socket 37, sealing is provided by disposing an O-ring 81 between a sleeve 45 and a tubular component portion 75. A robot assembly 10 and a gun assembly 20 have interengaging connecting parts 15, 22 for compressed air and water and a housing 36 including the electrical connector 30 is fixed to the robot assembly 10. The housing 61 is fixed in a position complementary with the gun assembly 20. As a result, the electrical connector is made usable for transmission of other electric control signals or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to electrical connectors, and more particularly to electrical connectors for use in industrial robots employed to perform resistance welding operations.

Conventional technology In automated welding lines, for example for the production of car bodies, several pairs of robotic welding machines are each dedicated to different tasks, which are constrained by the design of the spot welding electrodes of the welding guns controlled by the robot. It is known that. It has been proposed to improve the flexibility of robotic welding machines by providing each robot with two or more interchangeable welding guns, thereby reducing the number needed and reducing the number of robots or one welding gun. It has been suggested that it is possible to switch to a different welding gun.

The welding guns used in these robotic welding machines typically have a 415V three-phase power supply and water supply for cooling, and a supply of compressed air to control the movement of the electrodes to clamp the workpiece between the electrodes. Requires supply. As a result, connectors are required for these service operations so that one gun can be removed from the robot and automatically replaced with another gun.

For maximum flexibility of the robot, we designed the components of the gun exchange system to be as compact as possible, thereby absorbing the robot's proximity to the welding position within the vehicle body, while at the same time being able to accommodate the robot's proximity to the welding location within the vehicle body. It is desirable to be held in place by a "frame assembly machine". Due to the limited space, the water connections are necessarily close to the electrical connections. Inevitably, during connection and disconnection of welding guns, water may leak from the connector and into the electrical connection, causing a short circuit between its contacts. A short circuit in an electrical connection can result in the blowing of a fuse in the equipment, thereby requiring the assembly line to be shut down until the fuse is replaced. Additionally, arcs can occur between electrical connections, causing spark corrosion of the contacts and insulation between the contacts, thus greatly reducing the life of the electrical connections and ultimately requiring extended outage periods. At the same time, it may be necessary to replace small parts within the gun replacement system.

SUMMARY OF THE INVENTION The present invention provides an electrical connector for a Rojo welding machine in which the electrical contacts are effectively sealed together, thereby avoiding short circuits due to water leakage.

SUMMARY OF THE INVENTION According to one aspect of the present invention, an electrical connector for a robotic welding machine having an automatically interchangeable welding gun includes a pair of electrical contacts, one of the contacts an electrical connector defining a tubular socket and having another contact or a coupling device defining an interference fit within the socket and connecting each contact to a conductor, the coupling device and the conductor coupled thereto; are sealed within respective housings made of an insulating material, the bottle and the socket protruding from their respective housings, and the portion of the socket that protrudes from the housing of the socket is made of an insulating material. sheathed by a sleeve of
The portion of the bottle extending from the bottle housing is surrounded by a tubular component of insulating material, the inner diameter of the tubular component is greater than the outer diameter of the sleeve, and the portion between the sleeve and the tubular component when the bottle is engaged into the socket. A device for forming a seal is provided.

Preferably, the connector includes a plurality of pairs of interengagable contacts, one contact of each pair or complementary contacts disposed in spaced relation in a common housing, or complementary contacts in a separate common housing. arranged in the same spaced relationship.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings.

EXAMPLE The connector assembly illustrated in the accompanying drawings includes a robot assembly 10 as illustrated in FIG. 1 mounted on a robot arm and as illustrated in FIG. 2 forming a pair of welding guns. gun assembly 20.

The robot assembly IO includes a generally cylindrical housing 11. A series of conical nozzles [5] extend from the end face 12 of the housing 2 remote from the robot arm. Nozzle 15
is connected to a mouth 16 by which the nozzle can be connected to an external service via a flexible hose. Nozzle 15 includes a spring-loaded valve system that is opened when robot assembly 10 and gun assembly 20 are engaged and closed when assemblies 10 and 20 are separated.

Gun assembly 20, which has a generally cylindrical shape, has a series of mouths 22 corresponding to conical nozzles 15 on an end face 21 opposite face 11 of robot assembly IO. Mouth 22 has a seal engageable with nozzle 15 to form a seal therebetween, and also has a valve arrangement similar to that of nozzle 15 to open and close mouth 22.

The nozzle 15 and the complementary mouth 22 provide a connection for compressed air for controlling the orientation and clamping of the welding electrode and for cooling purposes to the transformer forming part of the welding electrode and the welding gun. connections for supplying and discharging water from them.

Three angularly spaced conical bins 17 on robot assembly 11 are connected to corresponding conical holes 23 on gun assembly 20.
A retaining absorbing arrangement is provided within the assembly to provide alignment of the two assemblies IO and 20 when the two assemblies IO and 20 are brought together. The robot assembly 10 also includes three similarly spaced pneumatically actuated dogs 18, which are connected to the assembly 1.
0 and 20 are adapted to engage into corresponding lugs 25 on gun assembly 20 to clamp assemblies IO and 20 together when engaged.

Robot assembly 10 and gun assembly 20 are also provided with interengagable low voltage electrical connectors 19 and 26 by which control signals can be communicated to the welding gun.

The welding current, typically 12,000 amps at 40 volts, is supplied by a transformer that constitutes part of the welding gun. This transformer is powered at 70 amps by a 415 volt three phase power supply, which is connected to the welding gun by a three pin electrical connector 30, illustrated in more detail in FIG. Electrical connector 30 connects socket assembly 31 mounted in the center of robot assembly 10 and gun assembly 2.
and a plug assembly 32 mounted in a corresponding position of 0.

Socket assembly 31 includes three contacts 35 disposed in spaced relation in a housing 36 made of an insulating material, for example an acetal resin such as Delrin®. Contact 35 includes a tubular socket portion 37 extending partially from housing 36 and a base portion 38 that spreads the axial loads applied to socket portion 37 when plug and socket assemblies 32 and 31 are engaged and separated. exists. A hole 39 transverse to the socket portion 37 is provided on the base portion 38 into which the conductor 30 can be engaged, the conductor 40 being a headless screw that engages in a threaded cross hole 42. 41 into the hole 39. Conductor 40 has an insulated sheath and exits housing 36 through its sidewall.

Each socket portion 37 of the contact 35 is connected to the housing 3
It is sheathed by a tubular sleeve in the form of an insulating material similar to 6. A flange portion 46 at one end of the sheath 45 abuts the base member 38 while the other end of the sleeve 45 extends beyond the end of the socket portion 37 so that the live contact 35
prevent accidental contact with A sleeve 45 is disposed through a hole 47 in housing 36, the inner end of which is counterbored to fit flange portion 46. A partition 48 is provided in housing 36 to separate contacts 35 and conductors 40 from each other.

A cover member 50 is fastened to the housing 36 by a series of screws 51 to close the housing 36. The sealing device 52 is provided between the cover member 50 and the housing 36 to ensure that any voids left between the contacts 35, conductors 40 and bulkhead 48 insulate the contacts 35 and conductors 40 from each other and prevent fluid from entering the connector. Filled with insulating sealant to ensure no damage. Suitable insulating sealants include silicone formulations: silicone rubbers, pastes or formulations, two-part room temperature vulcanization formulations; acrylic sealants: polyurethane formulations, or epoxy potting formulations.

Socket assembly 31 is secured to recess 54 in face 11 of robot assembly 10 by screws 55 .

Plug portion 32 of electrical connector 30 has three contacts 60 disposed in a housing made of an insulating material similar to housing 36.

Contact 60 is connected to housing 6 in the same spaced relationship as contact 35.
placed in 1. Each contact 60 has a pin portion 62, an enlarged diameter intermediate portion 63, and a larger diameter base portion 64. Pin portion 62 is located on the outside of housing 60. An intermediate portion 63 disposed within housing 60 provides a connector that can be connected to conductor 65 or contact 60.

A transverse hole 66 is provided in the intermediate portion 63 so that the conductor 65 can be engaged in the hole 66, and a headless screw 67 or a threaded hole 68 is provided so that the conductor 65 can be engaged in the hole 66. 66.

Base portion 64 serves to spread the axial loads applied to pin portion 62 of contact 60 when plug and socket assemblies 32 and 31 are engaged and separated.

Each contact 60 is surrounded by a tubular component 70 made of insulating material. Component portion 70 engages stem portion 64 and intermediate portion 63 of contact 60 within housing 61, and portion 75 extends halfway along pin portion 62 to form housing 6
1 or radially spaced apart from the pin portion 62 . It is tubular and located in the counterbore 74.

Conductor 65 has an insulating sheath that exits housing 61 through its sidewall. As in socket assembly 31,
Housing 6I is partitioned to separate contacts 60 and conductors 65 from each other.

The cover member 76 is threadedly fitted within the housing 61 and a sealing device 77 is provided therebetween.

The voids in the housing 61 may be filled with a seal, such as silicone, to prevent fluid ingress, similar to the socket assembly 31.

Portion 75 of tubular component 70 has an inner diameter greater than the diameter of sleeve 45 so that pin portion 62 of contact 60 forms an electrical connection when plug and socket assemblies 32 and 31 are brought together. The sleeve 45 extends into the tubular component 70 . A circumferential groove 80 or an elastomeric O-ring 81 is provided on each inner diameter of the tubular component 70.
The sleeve 45 engages the O-ring 81 when the connection is made.
and tubular component 70, thereby preventing fluid from reaching contacts 35 and 60.

The socket part 3 of the contact 35 to ensure good electrical contact with the tubular spring element 83 or the pin part 62 of the contact 60.
7. Alternatively, pin portion 62 of contact 60 can be axially split and springed apart.

The plug assembly 32 is positioned in a recess in the face 21 of the gun assembly 20 by shoulder locking screws 84, which locking screws have a small diameter to accommodate small misalignments of the socket and plug assemblies 31 and 32. is passed through an oversized elongated hole 85 in the housing song 61 to allow transverse movement of the housing.

Various modifications may be made without departing from the invention. For example, in the above embodiments the sleeve 4S and tubular component 70 are formed separately from the respective housings 31 and 61, or they can be molded as an integral part of the housing. Alternatively, each housing includes contacts 35 and 60 and associated conductors 4.
It can be of monolithic construction molded directly around 0 and 65. Also, the total number and arrangement of contacts 35 and 60 can be changed as desired.

Electrical contacts 35 and 60 may be made of a suitable conductive material, such as silver-plated brass.
and 60, or other removable or permanent fixing devices may be used, such as re-heading, heading, criss-crossing, cold soldering,
High temperature soldering or brazing may be used.

Although the invention has been described in connection with a robot-controlled resistance welding machine, the connector may also be used in other applications, particularly where there is a risk that conductive fluids may come into contact with the connector, such as multi-stage or press welding machines with rapid change equipment. can be used in However, the connector can be used where conductive fluid leakage is not a significant problem, for example in electrical connections between robots and stud welding equipment. Although the connector of the invention is particularly advantageous for use in high voltage applications, the connector can also be used for low voltage applications, for example without causing short circuits between contacts or equipment malfunctions. It can be used to transmit certain electrical control signals.

[Brief explanation of drawings]

FIG. 1 illustrates in plan view one portion of a connector assembly that may be coupled to an arm of a welding gun or robot controller;
The figures illustrate complementary surfaces of other parts of the connector assembly illustrated in FIG. 1 in plan view, and FIG. 3 shows a cross-section of the high voltage electrical connector of the connector assembly illustrated in FIGS. Illustrated in the figure. 10... Robot assembly, 15... Nozzle, 20.
...Gun assembly, 22...Mouth, 30...Electrical connector, 35...Contact, 36...Housing, 37...
... Tubular socket part, 39 ... Hole, 40 ... Conductor, 41 ... Headless screw, 45 ... Tubular sleeve,
48... Partition wall, 5' cutting bar member, 60... Housing, 61... Housing, 62... Pin portion, 6
5... Conductor, 66... Hole, 67... Headless piece, 7
5... Portion of tubular component, 76... Cover member,
80...groove, 81...0-ring.

Claims (1)

Claims: (1) An electrical connector (30) for a robotic welding machine having an automatically interchangeable welding gun, comprising a pair of electrical contacts (35, 60), one of the contacts (35) defines a tubular socket (37) and another contact (60) defines a pin (62) for an interference fit within the socket (37), and each contact (35, 60) indicates that it is a conductor. (40, 65
) can be connected to a coupling device (39, 41; 66, 67)
an electrical connector (30) having a coupling device (3
9, 41; 66, 67) and conductors connected thereto (
40, 65) are sealed within respective housings (36, 61) made of insulating material, with pins (62) and sockets (37) Their respective housings (61
, 36), and the portion of the socket (37) that projects from the socket housing (36) is provided with an outer sheath of insulating material (
The portion of the pin (62) extending from the pin housing (61) is surrounded by a tubular component (75) of insulating material, the inner diameter of the tubular component (75) being the outer diameter of the sleeve (45). larger than , and with pins (6
2) when the sleeve (4) is engaged into the socket (37).
5) and a tubular component (75), characterized in that a device (81) is provided for creating a seal between the tubular component (75). (2) a plurality of contacts (35) are arranged in spaced relationship in one housing (36), and a corresponding number of complementary contacts (60) are arranged in another housing (61);
2. The electrical connector of claim 1, wherein the electrical connectors are arranged in the same spaced relationship in the same spaced relationship. (3) Socket portion (37) of the one contact (35)
Electrical connector according to claim 1 or 2, characterized in that a sleeve (45) of insulating material sheathing extends beyond the end of the socket part (37). (4) a tubular component (75) surrounding said another contact (60);
4. Electrical connector according to claim 1, characterized in that the pins (62) extend only partway along the pins (62). (5) the circumferential groove (80) is connected to said tubular component (75);
an elastomeric ring (81) is disposed in said groove (80) so that when the pin (62) engages the socket (37), the sleeve (
Electrical connector according to any one of claims 1 to 4, characterized in that the electrical connector is engaged by the sleeve (45) and forms a fluid-tight seal between the sleeve (45) and the tubular component (75). . (6) The housing (36, 61) has a cover member (50,
76), and the cover member (50, 76)
6. Electrical connector according to any one of claims 1 to 5, characterized in that the connector (36, 61) forms a fluid-tight seal with the housing (36, 61). (7) Connection device (39, 4) for one contact (35, 60)
1; 66, 67) and the conductor (40, 65
) arranged in the housing (36, 61) and separated from those of the further contacts (35, 60) by a partition (48). Electrical connectors listed in paragraph 1. (8) The connecting device (39, 41; 66, 67) and the part of the conductor (40, 65) connected thereto are embedded in a sealing material. An electrical connector as described in any one of the clauses. (9) Claim 8, wherein the sealing material is a silicone compound; a silicone rubber, paste or compound; a two-part room temperature vulcanization compound; an acrylic sealant; a polyurethane compound; or an epoxy potting compound. Electrical connectors listed in . (10) Robot assembly (10) and gun assembly (20)
), and the robot and gun assembly (10, 20) includes interengaging connections (15, 2) for compressed air and water.
2) and comprising an electrical connector (30), wherein the electrical connector (30) is as defined in any one of claims 1 to 9. A housing (36) containing contacts (35) defining a tubular socket (37) is secured to the robot assembly (10) and a housing (61) having contacts (60) defining a pin (62). ) is fixed in a complementary position to the gun assembly (20). (11) Gun assembly (20)
Claim characterized in that the housing (61) is fixed in such a way as to allow limited lateral movement to accommodate slight misalignments of the pin (62) and the socket (37). Connector assembly according to item 10.