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CN-122003305-A - Connection system and method for feeding fasteners

CN122003305ACN 122003305 ACN122003305 ACN 122003305ACN-122003305-A

Abstract

Method for transporting fasteners and a connection system (10) for connecting fasteners (18) to a workpiece, comprising-a head (12) having a nose (14) provided with a holding device (16) for receiving fasteners to be connected to a workpiece, -a feeder for transporting fasteners from a storage magazine to the holding device, wherein the feeder comprises a feed tube adapted to receive fasteners from the storage magazine and to cause the fasteners to be driven to the nose (14) by entering the feed tube, -an air supply mechanism (S) comprising a source of compressed air (30) for delivering compressed air to the feeder (22) and driving fasteners from the storage magazine to the holding device within the feed tube (24), wherein the air supply mechanism (S) further comprises a plurality of valves (V1, V2, V3) arranged such that a plurality of compressed air pulses are provided to move fasteners (18) from the storage magazine to the holding device within the feed tube.

Inventors

  • Timo Kohlstedt
  • Hubert Ivor
  • MICHAEL MAYER
  • LIPPERT STEFAN
  • David Heather Ritchie
  • Wuwei Hurt
  • ADRIAN BECKER
  • Andre Atzbach

Assignees

  • 纽弗雷有限公司

Dates

Publication Date
20260508
Application Date
20241009
Priority Date
20231010

Claims (13)

  1. 1. A connection system (10) for connecting a fastener (18) to a workpiece, comprising: a head (12) having a nose (14) provided with a retaining means (16) for receiving a fastener to be connected to a workpiece, -A feeder for conveying fasteners from a magazine to the holding device, wherein the feeder comprises a feed tube adapted to receive fasteners from a magazine and cause the fasteners to be driven to the noses (14) by entering the feed tube; An air supply means (S) comprising a source of compressed air (30) for delivering compressed air to the feeder (22) and driving the fasteners from the magazine to the holding device within the feed tube (24), Characterized in that the air supply means (S) further comprises a plurality of valves (V1, V2, V3) arranged such that a plurality of compressed air pulses are provided to move the fastener (18) from the storage bin to the holding device within the feed tube.
  2. 2. The connection system (10) according to claim 1, wherein the air supply mechanism comprises at least: a first valve (V1) and a second valve (V2) connected in parallel, -A third valve (V3) connected in series with said first valve and said second valve.
  3. 3. The connection system (10) of claim 2, wherein the air supply mechanism includes a throttle valve (32), and wherein the first valve is adjustable by the throttle valve, wherein the second valve is a non-throttle valve.
  4. 4. A connection system (10) according to any one of claims 1 to 3, wherein the air supply mechanism comprises at least one quick acting valve, and wherein the third valve (V3) is a pulse valve.
  5. 5. The connection system (10) according to any one of claims 1 to 4, wherein the air supply mechanism (S) comprises a sensor unit (34) for measuring air consumption or detecting the presence of a fastener (18) in the feed tube (24).
  6. 6. A method of feeding fasteners into the nose (14) of a connector (12), comprising the steps of: -providing a connection system (10) according to any one of claims 1 to 5, -Providing a fastener and transporting the fastener with the feeder such that the fastener is moved up to the nose by pulsed air from the air supply mechanism such that: o during the delivery phase, the movement of the fastener is controlled by pulsed air; o in the arrival phase, the delivery of the fastener into the nose is controlled and at least one valve is closed.
  7. 7. The method according to claim 6, wherein the air supply mechanism (S) comprises a first valve and a second valve connected in parallel, and a third valve connected in series with the first valve and the second valve.
  8. 8. The method of claim 7, wherein in the first phase, the first valve and the second valve are turned on one after the other after a predetermined time X.
  9. 9. Method according to claim 7 or 8, wherein in the second phase the first and second valves (V1, V2) are opened and the third valve is pulsed with a predetermined pulse cadence.
  10. 10. The method according to any one of claims 7 to 9, wherein in the third phase the second and third valves (V2, V3) are closed one after the other, the first valve remaining closed.
  11. 11. The method of any of claims 6 to 10, wherein a sensor unit (34) detects the presence of fasteners in the feeder.
  12. 12. A method according to claim 11, wherein a control unit (36) adjusts the opening and closing of the valves (V1, V2, V3) in dependence of the data sent by the sensor unit.
  13. 13. A method according to any one of claims 6 to 12, wherein a control unit adjusts the opening and closing of the valves (V1, V2, V3) according to a predetermined given sequence.

Description

Connection system and method for feeding fasteners Technical Field The present invention relates to a connection system for connecting a fastener to a workpiece, and a method for feeding a fastener into the nose of a connection head by compressed air. Background In the present context, the term "fastening" or "connection" is intended to mean all methods of attaching elements to components, in particular metal or plastic elements to metal or plastic components, for example by means of adhesive bonding, screw connection, form-fitting connection (e.g. riveting, self-piercing riveting, blind riveting of rivets or nuts, rivetless riveting) or material fusion connection (e.g. welding, including short-cycle arc welding or drawn arc welding). Short cycle arc welding is commonly referred to as stud welding, although studs are not the only parts welded in this manner. Self-piercing rivets and related tools or devices for securing two or more pieces of material to one another are well known in the automotive industry. Self-piercing rivets are commonly used for non-critical joining to join two or more pieces of material to one another, such as assembling an automotive body using self-piercing rivets at a frame station. Stud welding is mainly used for, but not limited to, automotive production. In this context, metal elements, such as threaded and unthreaded metal studs, slings, nuts, etc., are welded to a metal plate or work piece of the vehicle body. These metal elements then serve as anchor points or mounting elements, for example for connecting passenger compartment trim, lines, wiring harnesses, etc., to the body metal. The metal element may be a weld stud having a shank and a head having a diameter slightly larger than the shank of the stud. The head is welded to the workpiece. Such connecting or fastening means are usually connected to a movable frame, in particular a robot, and comprise a joint with a nose provided with holding means for receiving and holding a connecting element to be connected to a workpiece. The drive mechanism may move the retaining device in the attachment direction to attach the fastener to the workpiece. Once the fastener is disposed in the holding device, conventional fastening or connecting methods may be performed. For example, a conventional stud welding process may be performed as follows, preferably using a drawn arc method. The fastener is first placed on the workpiece by the drive mechanism and the retaining device. A pilot current is then turned on, which current flows through the fastener and the workpiece. The fastener (or stud) is then lifted relative to the component by a drive mechanism (e.g., the drive mechanism is a linear drive). An arc is formed. The system then switches to the welding current. The opposite end surfaces of the fastener and the workpiece (or component) begin to melt due to the high welding current. The fastener is then lowered again onto the workpiece, causing the two melts to bond. The welding current is turned off at or slightly before the contact member and the arc are shorted. All molten material solidifies and a welded connection is established. The fastener needs to be fed to the connector and the holding means. For this purpose, the feeder is equipped with a feed tube for conveying the fasteners (or connecting elements) from the magazine to the holding device. Typically, a fixed supply separates the fasteners and then delivers them to the connector via a feed tube by compressed air. Individual separate fasteners (e.g., studs) are blown from the storage bin to the connector by compressed air through a feed tube or hose. While compressed air is widely used in such connection systems to deliver fasteners, this approach has some drawbacks. It is well known that compressed air systems are less energy efficient than other power sources. The process of compressing air requires a lot of energy and there may be energy losses during the transmission and conversion. Such inefficiency results in higher energy consumption and operating costs. In order to promote energy conservation and "green manufacturing" in the connection system, alternative power sources or increased efficiency of the compressed air system must be considered and measures taken to reduce energy waste and environmental impact. Various solutions have been proposed to remedy these problems. US2018222696A1 discloses a connection device in which the residual momentum and gravity can be used to interrupt the supply of compressed air at the end of the travel of the fastener along the feed tube to ensure that the fastener reaches the connection head. A connecting element passage sensor is provided so that when the sensor detects the presence of a fastener, the compressed air is shut off. Such a system may reduce compressed air consumption. However, a specific design of the supply or feeding device is required. Disclosure of Invention It is therefore an object of the present invention to provide a co