JPH0433665B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a pallet conveying device that carries objects to be conveyed, and particularly relates to a chain-driven pallet conveying device that conveys the pallets by running an endless chain. This invention relates to a pallet conveying device.

Technical Background of the Invention Conventionally, this type of pallet conveying device has been applied to an automatic soldering system, etc., and the configuration of this automatic soldering system will be described below. This system is equipped with a transport mechanism for soldering carriers (pallets) on which printed circuit boards are placed. This conveyance mechanism includes an endless chain, and the carrier is conveyed by the running of this chain. That is, this carrier has a protruding engagement pin that engages with the chain. The carrier is conveyed by running the chain with the engagement pin meshed with the chain. Further, the carrier is transported over the solder bath by the transport mechanism, and soldering to the printed circuit board is automatically performed during this transport. A conveyance direction converting section is arranged in front of the conveyance mechanism in the conveyance direction. This conveyance direction converter is configured to receive the carrier from the conveyance mechanism and to transfer it to a conveyance path different from the conveyance direction of the conveyance mechanism. By this,
After soldering, the printed circuit board is transferred to the next process together with the carrier.

Problems with the Background Art In the automatic soldering system with the above configuration, when the soldering carrier is transported by the transport mechanism,
It had the following shortcomings: That is, when a large number of carriers are continuously transported, it is difficult to match the transport interval of these carriers with the operation timing of the transport direction converting section. Therefore, if the conveyance interval is short, the carrier may reach the position of the conveyance direction converter and collide with the conveyance direction converter before the conveyance direction converter is ready to receive the carrier. As a result, there were problems such as the carriers being not reliably delivered at the conveyance direction changing section and the carriers being damaged due to collisions.

Purpose of the Invention This invention was made based on the above circumstances, and its purpose is to ensure that pallets (carriers) can be delivered at the conveyance direction changing section and to prevent damage to the pallets. An object of the present invention is to provide a pallet conveying device.

SUMMARY OF THE INVENTION This invention provides an engaging pin that can be projected and retracted from a pallet, a contact member that can be projected and retracted in the transport direction of a transport mechanism, and a contact member that can be projected and retracted in the transport direction of a transport mechanism. A stopper is provided at the conveyance end of the conveyance mechanism that can come into contact with the abutment part of the pallet being conveyed to the conveyance end, and the pallet has a transmission member that transmits the displacement of the abutment part to the engagement pin. and an engagement pin retraction mechanism for retracting the engagement pin into the pallet and releasing the engagement with the chain according to the abutment member that is retracted and displaced by contact with the stopper or the previous pallet. The present invention is characterized in that the pallet, which stops at the stopper position by disengaging the engagement pin and the chain, is transferred by the converter.

Embodiment of the Invention An embodiment of the invention will be described below based on the drawings.

FIG. 1 shows an automatic soldering system using the pallet conveying device of the present invention, where 1 is a carrier for soldering as a pallet. Objects to be transported, such as printed circuit boards A, can be placed on the carriers 1, respectively. Furthermore, an engagement pin 5 is provided protruding from the lower surface of the front side of the carrier 1 in the transport direction. The carriers 1 are transported by a transport mechanism 2. This conveyance mechanism 2 includes an endless chain 3. 4, 4 is roller chain 3
This is a sprocket that drives the vehicle. Therefore, the carrier 1 is conveyed by running the roller chain 3 with the engagement pin 5 meshed between the links of the roller chain 3. Further, the carriers 1 are configured to pass over the solder tank 6 by being transported by the transport mechanism 2, and soldering to the printed circuit boards A is performed during this passage. A loading/unloading section 7 for carrying printed circuit boards A is disposed at the rear of the conveying mechanism 2 in the conveying direction. The carry-in/out section 7 is configured to supply the printed circuit board A to the carrier 1 and send the carrier 1 to the transport mechanism 2.

In front of the transport mechanism 2 in the transport direction,
A conveyance direction converting section 8 is arranged. The conveyance direction conversion unit 8 is configured to receive the carrier 1 conveyed by the conveyance mechanism 2 and then transfer the carrier 1 to the return conveyance path 9. That is, the conveyance direction of this return conveyance path 9 and the conveyance direction of the conveyance mechanism 2 are opposite directions. Also, 10
The carrier 1 is transferred from the return conveyance path 9 to the carry-in/out section 7.
This is a conveyance direction changing section that changes the direction of conveyance. Therefore, the circulation path of the carrier 1 is configured in the order of the carry-in/out section 7, the conveyance mechanism 2, the conveyance direction conversion section 8, the return conveyance path 9, the conveyance direction conversion section 10, and the carry-out/input section 7.

A stopper 11 is arranged at the transport end of the transport mechanism 2. This stopper 11 comes into contact with the carrier 1 and prevents the carrier 1 from being conveyed. Further, when the carrier 1 comes into contact with the stopper 11, the engagement pin 5 of the carrier 1 is retracted into the carrier 1 by an engagement pin retraction mechanism 12. That is,
The engagement pin retraction mechanism 12 is constructed as shown in FIGS. 3 and 4. First, the engagement pin 5 is slidably fitted into an insertion hole 13 passing through the carrier 1, and the lower end of the engagement pin 5 can protrude and retract from the lower surface of the carrier 1. A protruding/retracting guide hole 14 is formed in the intermediate portion of the engaging pin 5, and the protruding/retracting guide hole 14 is penetrated in a direction perpendicular to the axial direction of the engaging pin 5. An abutting rod 15 (corresponding to an abutting member) passes through the protruding and recessing guide hole 14. This contact rod 15 is provided in the carrier 1 so as to be slidable along the transport direction of the carrier 11, corresponding to the position of the stopper 11. The tip end of this contact rod 15 can protrude to the outside from a position where it contacts the stopper 11 on the front surface of the carrier 1 in the transport direction. Further, a pressure spring 16 is provided on the proximal end side of the contact rod 15, and this pressure spring 16 always urges the contact rod 15 in the direction of protrusion. It protrudes to the front in the transport direction so that it can be protruded and retracted. A plate cam 17 (corresponding to a transmission member) is attached to the contact rod 15. This plate cam 17 has a tapered surface 17a.
The tapered surface 17a is formed such that the protruding side of the abutment rod 15 faces upward. Then, when the contact rod 15 protrudes,
When the inner surface of the protruding/retracting guide hole 14 comes into contact with the lower side of the tapered surface 17a as shown in FIG. 3, the engaging pin 5 is set to be in a protruding state. Furthermore, when the abutment rod 15 is retracted, the tapered surface 17a deeply enters the protrusion/retraction guide hole 14 and pushes up the engagement pin 5, so that the engagement pin 5 is in the retracted state. It is something.

The automatic soldering system configured as described above supplies the printed circuit boards A to the carriers 1 in the loading/unloading section 7, and then transfers the carriers 1 to the transport mechanism 2. At this time, the engagement pin 5 protrudes from the bottom surface of each carrier 1 and connects the chain 3 of the transport mechanism 2.
As the chain 3 runs, the carriers 1 are conveyed.

Note that even during this transportation, the printed circuit board A...
It is soldered to the When the first carrier 1 reaches the transport end of the transport mechanism 2, the abutment rod 15 of the carrier 1 abuts against the stopper 11 and is retracted. By this,
As shown in FIG. 4, the engagement pin 5 is pushed up by the plate cam 17 and recessed into the carrier 1, and the engagement between the engagement pin 5 and the chain 3 is released. Therefore, at this time, the driving force from the chain 3 is not transmitted to the carrier 1,
This carrier 1 is kept in a standby state in contact with the stopper 11. Further, when the next carrier 1 that is transported comes into contact with the first carrier 1, the engagement between the engagement pins 5 and the chain 3 is released, and the transport is temporarily stopped. . In this way, the carriers 1 . In such a state, the carriers 1 .
can be transferred to. As a result, the carrier 1 is returned to the unloading section 7 via the return conveying path 9 and the conveying direction converting section 10. Also, the soldered printed circuit board A is taken out from the carrier 1 here. Note that after the printed circuit board A is taken out, a new printed circuit board A is supplied to the carrier 1 and transferred to the transport mechanism 2. When the first carrier 1 is transferred from the transport mechanism 2 to the return transport path 9 by the transport direction converter 8, the transport of this carrier 1 is stopped immediately before the transport direction of the carrier 1 at the next position. There's nothing left to do. Therefore, when the abutting rod 15 is projected from the front surface of the carrier 1, the engagement pin 5 is again projected from the bottom surface of the carrier 1. As a result, the engagement pin 5 and the chain 3 of the conveyance mechanism 2 engage again, and the carrier 1 is conveyed to the position of the stopper 11. Further, when the stopper 11 reaches the position, the abutment rod 15 is moved to the stopper 11.
1, the engagement between the engagement pin 5 and the chain 3 is released. As a result, the carrier 1 at the next position is transported to the stopper 11 position and waits at this position. Similarly, the carriers 1 are transported one after another and are kept on standby behind the stopper 11 in the transport direction. Therefore, according to the conveying device of this embodiment, since the carriers 1 are sequentially waited behind in the conveying direction from the position of the stopper 11, the conveying direction converting section 8 changes the carriers at its own operation timing. 1... can be exchanged, and this exchange can be carried out reliably. As a result, there is no need to match the transport interval of the carriers 1 in the transport mechanism 2 with the operation timing of the transport direction converter 8, resulting in excellent workability. Further, the carrier 1 does not collide with the conveyance direction converting section 8, and damage to the carrier 1 can be prevented.

Note that this invention is not limited to the above embodiment. For example, the pallet conveying apparatus of the present invention is applicable not only to automatic soldering systems, but also to many other conveying systems.

Effects of the Invention As explained above, according to the present invention, the pallets conveyed by the conveyance mechanism can be kept waiting sequentially at the rear from the stopper position. Therefore,
Pallets can be delivered at the conversion unit's own operating timing. Therefore, it is possible to reliably deliver the pallets, and also to prevent damage to the pallets, which provides various excellent effects.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a configuration diagram of an automatic soldering system, FIG. 2 is an enlarged view of the conveyance end side of the conveyance mechanism, and FIGS. 3 and 4.
The figure is an enlarged sectional view of the front portion of the carrier, showing the protruding and recessed states of the engagement pins. 1...Carrier (pallet), 2...Transportation mechanism,
3... Chain, 5... Engaging pin, 8... Conveying direction conversion unit, 12... Engaging pin retraction mechanism, 15...
Contact rod (contact member), 17...plate cam (transmission member).

Claims (1)

[Scope of Claims] 1. A pallet on which an object to be transported is placed and transported; an engaging pin protruding from the pallet that can be projected and retracted; and an engaging pin that is engaged with an endless chain. a chain-driven conveyance mechanism that continuously conveys the pallet as the chain runs; and an abutment member that protrudes from the front of the pallet in the conveyance direction and that can protrude and retract in the conveyance direction of the conveyance mechanism. and a stopper disposed at the conveyance end of the conveyance mechanism in correspondence with the abutment member and capable of abutting against the contact portion of the pallet being conveyed to the conveyance termination end; It has a transmission member that transmits the displacement of the abutting portion to the engaging pin, and the engaging pin is moved into the pallet according to the abutting member that is retracted and displaced by contact with the stopper or the previous pallet. an engagement pin retraction mechanism for releasing the engagement with the chain by recessing the engagement pin into the chain; and a conversion unit for transferring the pallet that stops at the stopper position when the engagement between the engagement pin and the chain is released. A pallet conveying device characterized by: