JP4611793B2 - Tray return device and tray return method - Google Patents

Description

  The present invention relates to a tray return device and a tray return method, and more particularly to a tray return device and a tray return method for returning an empty tray after a workpiece is taken out from a tray supplied by a tray supply path.

  For example, in an automobile production line, a tray on which a workpiece is placed is conveyed toward a component assembling step by a workpiece carry-in path constituted by a roller conveyor or the like. In general, in such a production line, the trays carried in the part assembling process are sequentially supplied to the work take-out position, and the work taken out from the tray supplied to the work take-out position is assembled to the vehicle body. In such a production line, it is necessary to return a tray that has been emptied after the workpiece is taken out. Therefore, in the article carry-out monitor device of Patent Document 1, when a tray with an object to be inspected is placed at the entrance, the entrance conveyor is activated and the tray is automatically guided to the intermediate conveyor, and the upper surface detector Then, after the measurement of the radioactive contamination level of the inspection object and the determination of whether or not the inspection object can be carried out are carried out, the tray is conveyed by the intermediate conveyor to the free roller conveyor in the stocker unit.

  Then, the door of the stocker unit is opened by the measurer, the object to be inspected is taken out and the door is closed, and then the article removal confirmation button for confirming the removal of the article is operated. The article take-out confirmation button serves both as an article take-out confirmation and an instruction to return the tray to the entrance. At the same time as the article take-out confirmation button is operated, the entrance conveyor drive unit and the intermediate conveyor drive unit are opposite to the measurement operation. Moving in the direction, the tray is returned to the inlet. At the same time, one end of the free roller conveyor is raised by the roller raising / lowering drive device of the stocker unit and the free roller conveyor is inclined, so that the tray is moved to the intermediate conveyor by its own weight fall, and the tray is moved. Returned to the entrance. In addition, by operating the tray return confirmation button, which is used to confirm when the tray has returned to the entrance normally, and to give instructions to return the free roller conveyor to the origin, and to stop the entrance conveyor drive unit and the intermediate conveyor drive unit. Each drive unit stops in the standby state for the next measurement, and the tray return operation is completed.

However, in the article carry-out monitoring device, an electric motor is used for each of the drive source for driving the entrance conveyor and the intermediate conveyor and the drive source (actuator) for tilting the flare roller conveyor of the stocker unit. The apparatus becomes complicated and the maintenance becomes complicated, and the running cost increases. In addition, by including a drive source and a control unit for controlling the drive source, the apparatus is increased in size, requiring a large installation space and increasing the equipment cost. Furthermore, in the article carry-out monitoring device, the route for transporting the tray from the entrance to the stocker unit and the route for returning the tray from the stocker unit to the entrance are the same, so the next article is loaded until the tray return operation is completed. When the placed tray cannot be put in and the cycle time for taking out the article is short, the application is difficult. In addition, when it is necessary to take out the workpiece from the tray with both hands, it is difficult for the operator to operate the article take-out confirmation button. Thus, although it is conceivable to use a foot switch as the article take-out confirmation button, there is a safety problem.
JP-A-8-166458 (paragraph numbers 0008 to 0010, FIG. 1)

Therefore, the present invention has been made in view of the above circumstances, and a first object is to automatically return an empty tray after a work is taken out, and to simplify and reduce the size. To provide a tray return device.
A second object is to provide a tray return method that can automatically return an empty tray after a workpiece is taken out, and that can simplify and downsize the apparatus.

  In order to achieve the first object, the invention according to claim 1 of the present invention is such that a tray on which a workpiece is placed is provided in a workpiece conveyance line supplied by a tray supply path, and the workpiece is taken out. A tray return device for returning empty trays, a tray return path installed below the tray supply path for removing workpieces and transporting empty trays, and the tray return path A lifting table that can be moved up and down between the tray supply path and a lift table that is provided on the lifting table and is positioned at the rising end position so as to be connected to the tray supply path and the lifting table at the lower end position. A tray transfer path connected to the tray return path by positioning, a lowering operation restricting means for restricting a lowering operation of the lifting table located at the rising end position, and a tray supply By detecting that a workpiece has been taken out from the tray supplied to the tray delivery path by the path, and by detecting that the workpiece has been removed from the tray on the tray delivery path by the workpiece removal sensing means. The lowering operation restriction releasing means for releasing the restriction of the lowering operation of the lifting table by the lowering movement restricting means, the rising operation restriction means for restricting the lifting operation of the lifting table located at the lower end position, and the tray as a tray delivery path The tray carry-out sensing means that senses that the tray has been carried out to the tray return path, and the ascending operation restricting means by sensing that the tray has been carried out from the tray delivery path to the tray return path by the tray carry-out sensing means Lifting operation restriction releasing means for releasing the restriction of the lifting operation of the lifting table by the A chain member that is engaged with a fixed pulley provided at the end, and having one end connected to the lifting table and the other end suspended from the balance weight. When the restriction of the lowering operation of the lifting table by the restricting means is released, the lifting table on which the tray from which the workpiece has been taken out and emptied is placed is lowered, and by the lifting operation restricting means by the lifting operation restriction releasing means The weight is set so that the lifting table after the tray is carried out is lifted by releasing the lifting operation restriction of the lifting table.

  According to a second aspect of the present invention, in the tray return device according to the first aspect, the lowering movement restricting means is provided so as to be rotatable around a first rotation shaft provided in the apparatus main body, and is formed by the upper end. A first rotary arm that supports the elevating table and whose lower end is restricted and its rotational movement is restricted; and a second rotary shaft that is provided in the apparatus main body, and is provided so as to be rotatable. And a second pivoting arm whose lower end is engageable with the upper end of the first pivoting arm, and the lowering movement restriction release means is supplied to the tray delivery path. The second rotating arm is rotated around the second rotating shaft by the tray, the work placed on the tray is taken out, and the tray is pushed back by the weight of the second rotating arm. The upper end of the first rotating arm is the second rotating arm. By being operated by the lower end, wherein the first rotating arm is configured such that the first is pivoted around the pivot shaft downward movement restricting means is released.

  According to a third aspect of the present invention, in the tray return device according to the first or second aspect, the ascending operation restricting means is formed in an L shape and around a third rotation shaft provided in the apparatus main body. A third rotary arm which is provided so as to be pivotable and whose one end can be engaged with the lifting table and whose other end is regulated and the pivoting operation is regulated; A fourth rotary arm that is rotatably provided around a fourth rotary shaft provided at one end, with one end protruding into the tray return path, and one end at the other end of the fourth rotary arm. A lifting member that is pivotably connected and is pivotally connected to a predetermined portion near the other end of the third pivoting arm. The fourth rotating arm is rotated around the fourth rotating shaft by the tray traveling on the Linkage as pivot arm is released the third is the rotation around the rotation axis increases movement limiting means is characterized in that it is configured.

  In order to achieve the second object, the invention according to claim 4 of the present invention is a method of returning a tray that has been emptied after the workpiece is taken out from the workpiece conveyance line, and the workpiece is removed from the tray. The removal is detected by the difference in weight between the tray on which the workpiece is placed and the tray from which the workpiece has been removed and is emptied. Is lowered and held at the lower end position, the empty tray is carried out to the tray return path, the empty tray is returned, and then the empty tray is loaded. The lifting table after the tray is carried out is lifted using a weight difference between the placed state and the state after the tray is carried out.

  Therefore, according to the first aspect of the invention, the tray on which the work is placed is supplied to the tray delivery path, and the work is taken out from the tray. The restriction of the lowering operation is released, and the lifting table on which the empty tray is placed is lowered from the rising end position toward the lowering end position. Then, when the empty tray is carried out from the tray delivery path to the tray return path, the lifting operation restriction releasing means lifts the lifting movement restriction of the lifting table, and the lifting table is moved from the lower end position. Raised toward the rising end position. When the lifting table reaches the rising end position, the tray delivery path is connected to the tray supply path, and the lowering operation of the lifting table is restricted by the lowering action restricting means.

In the second aspect of the invention, the second rotating arm is rotated around the second rotating shaft by the tray supplied to the tray delivery path, and the work placed on the tray is taken out. As a result, the tray is pushed back by the weight of the second rotating arm. As a result, the upper end of the first rotating arm is operated by the lower end of the second rotating arm, and the first rotating arm is rotated around the first rotating shaft to move down. The restriction means is released.
In the invention according to claim 3, the fourth rotating arm is rotated around the fourth rotating shaft by the tray carried out to the tray return path, and the third rotating arm is moved to the third rotation. The ascending motion restricting means is released by rotating around the moving shaft.
In the invention according to claim 4, the lifting table is automatically lowered using the weight difference between the tray and the tray that has been emptied and the empty tray is returned. The lifting table is raised using the difference in weight between the state where the tray is placed and the state after the tray is unloaded.

  It is possible to provide a tray return device and a tray return method capable of automatically returning a emptied tray after the workpiece is taken out and simplifying and downsizing the tray.

  An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the tray return device 1 is provided in a part assembling process of an automobile production line, and a work 3 (exhaust pipe in this embodiment) placed on the tray 2 is a tray. The tray is supplied to the tray delivery path 5 by the supply path 4. Then, when the work 3 is taken out from the tray 2 supplied from the tray supply path 4 on the tray transfer path 5, the empty tray 2 is transferred from the tray transfer path 5 to the tray return path 6. The structure is returned. The tray supply path 4 is constituted by a roller conveyor, and the tray 2 on which the work 3 is placed is transported in the left direction in FIG. 1 by giving an inclination to the roller conveyor. Further, the tray return device 1 is configured such that the tray return path 6 is configured by a roller conveyor installed below the tray supply path 4, and the tray return path 6 has a reverse gradient with respect to the tray supply path 4. By giving the inclination, the tray 2 on the tray return path 6 is transported in the right direction in FIG.

  As shown in FIGS. 2 and 3, the tray return device 1 has a lifting table 9 guided in the vertical direction in FIG. 3 by four guide pillars 8 erected on the main body frame 7 (device main body). Prepare. The elevating table 9 has a structure in which a frame is formed in a rectangular shape and cylindrical guided portions 10 disposed at the four corners of the frame are guided by the guide pillars 8. On the upper surface of the elevating table 9, the tray delivery path 5 constituted by a roller conveyor is provided so as to be swingable (seesaw operation) around the swing shaft 11. The swing shaft 11 is disposed on the right side in FIG. 3 with respect to the tray transfer path 5 with respect to the position where the tray transfer path 5 is horizontal around the swing shaft 11. Accordingly, the tray delivery path 5 is configured such that the left side in FIG. 3 is lowered and has the same inclination with respect to the tray supply path 4. Further, the lift table 9 is provided with a pair of restricted members 12 (downward movement restricting means) on both sides in the width direction (vertical direction in FIG. 2) of the left end portion in FIG.

  As shown in FIGS. 2 and 3, the tray return device 1 includes the first rotation shafts on both sides in the width direction (vertical direction in FIG. 2) of the left end portion in FIG. 3 of the main body frame 7. A first turning arm 14 (downward movement restricting means) that can turn around 13 is provided. Each first rotating arm 14 is locked by a locking pin 16 projecting from the main body frame 7 with a locked portion 15 formed at the lower end thereof, so that the direction of 12 o'clock (in FIG. 3). Positioned in a state tilted in the clockwise direction in FIG. Further, at the upper end of each first rotating arm 14, a lowering restriction roller 17 (downward movement restricting means) whose axis is arranged in parallel with the rotating shaft of each turning arm 14 is provided. In a state where the locked portion 15 is locked by the locking pins 16, the lowering restriction rollers 17 are brought into contact with the lower surfaces of the restricted members 12. Thereby, in this tray return apparatus 1, as shown in FIG. 3, the said raising / lowering table 9 is positioned and hold | maintained to a raise end position, and the said tray delivery path 5 is connected to the said tray supply path 4. As shown in FIG. ing.

  As shown in FIGS. 2 and 3, the tray return device 1 includes the second rotation shafts on both sides in the width direction (vertical direction in FIG. 2) of the left end portion of the main body frame 7 in FIG. 3. A second turning arm 20 (downward movement restriction releasing means) that can turn around 19 is provided. Each second rotating arm 20 is attached to the main body frame 7 via each bracket 18, and a tray sensing part 21 is formed on one side and a lowering restriction releasing part 22 is formed on the other side. Then, as shown in FIG. 3, each second turning arm 20 is restricted from turning in the clockwise direction in FIG. 3 by a restriction pin 23 provided in each bracket 18, and FIG. As shown in FIG. 4, the rotation operation in the counterclockwise direction in FIG. 4 is restricted by the restriction pin 24 provided on each bracket 18. Further, as shown in FIG. 7, each second turning arm 20 has a lowering restriction releasing lever 26 (a lowering action restriction releasing means) that can be turned around a turning center 25 at a lowering restriction releasing portion 22. Is provided.

  Then, as shown in FIGS. 3 and 4, the tray return device 1 is supplied to the tray delivery path 5 from the tray supply path 4 and travels on the tray delivery path 5 by each tray 2. When the tray sensing unit 21 of the rotating arm 20 is pushed in, each second rotating arm 20 is rotated around each second rotating shaft 19 in the counterclockwise direction in FIG. ing. At this time, in the tray return device 1, the lowering restriction release levers 26 of the second rotation arms 20 are released from the lowering restriction provided on the first rotation arms 14 coaxially with the lowering restriction roller 17. A state in which each second rotating arm 20 shown in FIG. 4 is raised by rotating in the clockwise direction in FIG. 7 around each rotation center 25 while being in contact with the roller 27 (lowering operation restriction releasing means). Then, one side of each descent restriction release lever 26 is directed downward by its own weight. Then, as shown in FIG. 6, the empty tray 2, whose workpiece 3 is taken out and reduced in weight, is pushed back to the right in FIG. 4 by the weight of each second rotating arm 20, thereby Each descent restriction release lever 27 has one end locked to a restriction pin 28 (see FIG. 7) and its rotation operation in the counterclockwise direction in FIG. The other end of 26 is pushed in.

  In the tray return device 1, each lowering restriction release roller 27 is pushed in by each lowering restriction release lever 26, so that each first turning arm 14 moves around each first turning shaft 13 as shown in FIG. Is rotated counterclockwise. Thereby, the engagement between each lowering restriction roller 17 and each regulated member 12 is released, and the lowering restriction of the lifting table 9 is released, whereby the empty tray 2 from which the workpiece 3 has been taken out becomes the tray delivery path 5. The elevating table 9 placed thereon is guided by the guide pillars 8 and lowered. As shown in FIG. 3, the tray return device 1 is provided with fixed pulleys 29 on both sides of the body frame 7 in the width direction (vertical direction in FIG. 2), and each fixed pulley 29 has one end. A chain member 31 fixed to the lifting table 9 and having a balance weight 30 suspended from the other end is engaged. As shown in FIGS. 3 and 8, the tray return device 1 is provided as an ascending operation restriction means and ascending action restriction release means on both sides in the width direction (vertical direction in FIG. 2) below the start end of the tray return path 6. The link mechanism 32 is configured.

  As shown in FIG. 8, each link mechanism 32 includes an L-shaped substrate 33 attached to the main body frame 7, and a third circuit formed in the L-shape and provided on the main body frame 7. A third turning arm 35 that can turn around the moving shaft 34, and a fourth turn that can turn around a fourth turning shaft 36 that is formed in an L shape and is provided on the substrate 33. A moving arm 37, and a flange member 38 having one end rotatably connected to the third rotating arm 35 and the other end rotatably connected to the fourth rotating arm 37. Is done. Note that reference numeral 39 shown in FIG. 8 is the same as that in FIG. 8 around the third rotating shaft 34 of the third rotating arm 35 because one end of the third rotating arm 35 is locked. A restricting pin that restricts the clockwise rotation operation, and reference numeral 40 denotes a fourth pin of the fourth rotating arm 37 by locking the side end surface of the fourth rotating arm 37. 4 is a restriction pin that restricts the turning operation in the counterclockwise direction in FIG. Hereinafter, the state in which the rotation operation of each of the rotation arms 35 and 37 is restricted by the restriction pins 39 and 40 is referred to as an initial state of each link mechanism 32.

  As shown in FIG. 8, in each link mechanism 32, in the initial state, the ascending restriction roller 41 provided at the other end of the third rotating arm 35 is disposed in the ascending / descending path of the ascending / descending table 9. In addition, the tip of the tray sensing unit 42 provided on one side of the fourth rotating arm 37 is configured to protrude onto the tray return path 6. As a result, the tray return apparatus 1 is configured so that the elevating table 9 on which the empty tray 2 is placed on the tray delivery path 5 immediately before the elevating table 9 descends from the ascending end position and reaches the descending end position. When the restricting member 43 disposed on both sides in the width direction (vertical direction in FIG. 2) of the right end portion in FIG. 3 presses the ascending restriction roller 41 of each link mechanism 32, the third rotating arm 35. Is rotated around the third rotation shaft 34 in the counterclockwise direction in FIG. Further, in the tray return device 1, when the lifting table 9 reaches the lower end position, the third rotating arm 35 rotates around the third rotating shaft 34 in the clockwise direction in FIG. By returning to the initial state, the regulated member 43 is locked by the elevation regulating roller 41, and the raising operation of the lifting table 9 is regulated.

  As shown in FIG. 5, the tray return device 1 is configured so that the tray delivery path 5 moves around the swing shaft 11 in the clockwise direction in FIG. 5 when the lifting table 9 reaches the lowered end position. , The tray delivery path 5 is configured so that the inclination of the tray delivery path 5 is aligned with the inclination of the tray return path 6 and the tray delivery path 5 is connected to the tray return path 6. Thereby, in the tray return device 1, when the lifting table 9 reaches the lower end position, the empty tray 2 is transferred from the tray transfer path 5 to the tray return path 6. The empty tray 2 is structured to be returned to the right in FIG. Then, as shown in FIG. 8, each link mechanism 32 is operated by the tray sensing part 42 of the fourth rotating arm 37 being operated by the tray 2 traveling in the right direction in FIG. The fourth rotating arm 37 is rotated around the fourth rotating shaft 36 in the clockwise direction in FIG. 8, so that the third rotating arm 35 is rotated around the third rotating shaft 34. It is structured to be rotated counterclockwise in FIG.

  As a result, in the tray return device 1, the engagement between the rise restricting roller 41 of the third rotation arm 35 of each link mechanism 32 and each regulated member 43 of the lift table 9 is released, and the lift table 9 is lifted. The lifting table 9 is lifted by the weight of the balance weight 30 by releasing the restriction of the operation. Each link mechanism 32 is returned to the initial state by its own weight after the tray 1 passes through the tray sensing unit 42 of the fourth rotating arm 37. The tray return device 1 is configured such that immediately before the ascending / descending table 9 reaches the ascending end position, the descending restriction rollers 17 of the first rotating arms 14 are moved by the regulated members 12 of the ascending / descending table 9. By being operated, each of the first rotating arms 14 is rotated around each first rotating shaft 13 in the counterclockwise direction in FIG. Further, when each regulated member 12 passes through each descending regulation roller 17, each first rotation arm 14 is rotated around each first rotation shaft 13 in the clockwise direction in FIG. 3. Returning to the original position, the lowering restricting roller 17 of each first rotating arm 14 is brought into contact with the lower surface of each regulated member 12, so that the lowering operation of the lifting table 9 that has reached the rising end position is performed. It has a regulated structure.

  As shown in FIG. 3, in the tray supply path 4, the leading tray 2 on the tray supply path 4 has a predetermined timing on both sides in the width direction (vertical direction in FIG. 2) of the lower left end in FIG. Thus, a tray supply mechanism 44 that is supplied to the tray delivery path 5 is provided. Each tray supply mechanism 44 includes a shaft member 45 that is rotatably supported around an axis, a lever 46 that is fixed to one end of the shaft member 45 and has a weight attached to an intermediate position in the longitudinal direction, and the shaft member. The first stopper 47 is fixed to the other end of the shaft 45 and positioned at a predetermined angular phase around the shaft center of the shaft member 45 with respect to the lever 46, and is fixed to the longitudinal intermediate portion of the shaft member 45. And a second stopper 48 which is positioned at a predetermined angular phase around the axis of the shaft member 45 with respect to the first stopper 47. As shown in FIG. 5, in each tray supply mechanism 44, the shaft member 45 is rotated around the shaft center by the moment of the weight of the lever 46 in a state where the lifting table 9 is located at the lower end position. As a result, the second stopper 48 is engaged with the convex portions 49 disposed on both sides in the width direction (vertical direction in FIG. 2) of the leading tray 2 so that the leading tray 2 waits. Yes.

  In addition, each tray supply mechanism 44 is operated so that the lever 46 of each tray supply mechanism 44 is operated by each operation plate 50 of the elevating table 9 rising from the descending end position toward the ascending end position, and the shaft member 45 is rotated about the axis. 3 and is held horizontally, as shown in FIG. 3, the engagement between the convex portions 49 on both sides in the width direction of the front tray 2 and the second stopper 48 is released, and the front The tray 2 is configured to be supplied in the left direction in FIG. As shown in FIG. 4, the tray 2 to be supplied next is moved leftward in FIG. 4 by engaging the first stopper 47 of each tray supply mechanism 44 with each convex portion 49. The movement is held in a restricted state. Then, as shown in FIG. 5, the tray 2 to be supplied next moves the shaft member 45 by the moment due to the weight of the lever 46 when the elevating table 9 is moved from the ascending end position toward the descending end position. By rotating around the axis, the engagement between each convex portion 49 and the first stopper 47 of each tray supply mechanism 44 is released.

  As a result, the tray 2 to be supplied next is moved by a predetermined distance in the left direction in FIG. 5, and each convex portion 49 is engaged with the second stopper 48 of each tray supply mechanism 44. The supply path 4 is on standby at the left end in FIG. Each tray supply mechanism 44 is provided with a roller to be brought into contact with the operation plate 50 and each convex portion 49 of the tray 2 at the tip of each of the lever 46, the first stopper 47, and the second stopper 48. .

  Next, the operation of the tray return device 1 will be described. First, as shown in FIGS. 3 and 4, when the tray 2 on which the work 3 is placed is supplied from the tray supply path 4 to the tray delivery path 5, the tray sensing unit 21 of each second rotating arm 20. However, when the tray 2 traveling on the tray delivery path 5 is pushed in the left direction in FIG. 3, each second rotating arm 20 rotates counterclockwise around each second rotating shaft 19. The tray 2 on the tray delivery path 5 is positioned at the workpiece take-out position (position shown in FIG. 4) by each of the standing tray sensing units 21 that are moved. Each descent restriction release lever 26 (descent operation restriction release means) is turned by rotating each second turning arm 20 counterclockwise around each second turning shaft 19. Each lowering restriction roller 17 (lowering restriction release roller 27) is moved from the left side to the right side in FIG. 7 while rotating around the moving center 25 in the clockwise direction in FIG. Further, as shown in FIG. 4, the tray 2 to be supplied next is engaged with the first stopper 47 of each tray supply mechanism 44 in the left direction in FIG. The movement is restricted and the vehicle waits at the position shown in FIG.

  Next, in the state shown in FIG. 4, when the work 3 of the tray 2 at the work take-out position is taken out and the total weight of the tray 2 (weight including the work 3 of the tray 2) is reduced, FIG. As shown in the drawing, each second rotating arm 20 is rotated by its own weight around each second rotating shaft 19 in the clockwise direction in FIG. 6, and the empty tray 2 ( Hereinafter, the empty tray 2 is simply pushed in a right direction in FIG. 6 by a predetermined distance. On the other hand, when each second rotation arm 20 is rotated about each second rotation shaft 19 in the clockwise direction in FIG. 6 and each tray sensing unit 21 is tilted, each lowering restriction release lever 26 is moved. Accordingly, each lowering restriction release roller 27 is operated, and each first rotation arm 14 is rotated counterclockwise around each first rotation shaft 13. As a result, the engagement between each lowering restriction roller 17 of each first rotating arm 14 and each regulated member 12 (lowering movement restriction means) of the lifting table 9 is released, as shown in FIG. The lifting table 9 on which the empty tray 2 is placed on the tray delivery path 5 is lowered against the weight of the balance weight 30.

  As shown in FIG. 5, in the state where each second rotating arm 20 is returned to the initial state (the state in which the rotating operation is restricted by the restriction pin 23), each first turning arm 14. Is restored to its initial state (the locked portion 15 is locked by the locking pin 16) by its own weight. When the elevating table 9 is lowered, the shaft member 45 of each tray supply mechanism 44 is rotated so that each first stopper 47 is engaged with each convex portion 49 of the tray 2 to be supplied next. When the tray 2 to be supplied next is released and moved to the left in FIG. 4, and the convex portions 49 are locked by the second stoppers 48, the tray 2 to be supplied next is the tray 2. It waits in the left end part in FIG. And just before the raising / lowering table 9 reaches | attains a descent | fall end position, the raising control roller 41 of each link mechanism 32 (ascending operation restriction means, raising action restriction release means) is pressed by each regulated member 43 of the raising / lowering table 9. The third turning arm 35 is turned around the third turning shaft 34 in the counterclockwise direction in FIG.

  As shown in FIG. 5, when the lifting table 9 reaches the lower end position, the third rotating arm 35 rotates around the third rotating shaft 34 in the clockwise direction in FIG. Returns to the initial state. As a result, the regulated member 43 is locked by the ascent regulating roller 41 and the ascending operation of the elevating table 9 is regulated. When the elevating table 9 reaches the lower end position, the tray delivery path 5 is rotated in the clockwise direction in FIG. 5 around the swing shaft 11, and the inclination of the tray delivery path 5 is changed to the tray return path. 6 and the tray delivery path 5 is connected to the tray return path 6. As a result, the empty tray 2 is transferred from the tray transfer path 5 to the tray return path 6, and the empty tray 2 is returned to the right in FIG. 5 by the tray return path 6. Then, as shown in FIG. 8, the tray sensing unit 42 of the fourth rotating arm 37 of each link mechanism 32 is operated by the tray 2 to be returned, and each fourth rotating arm 37 is moved to each of the first rotating arms 37. 8 is rotated in the clockwise direction in FIG. 8, so that the third rotating arm 35 of each link mechanism 32 is rotated around the third rotating shaft 34 in the direction opposite to that in FIG. 8. It is rotated clockwise.

  As a result, the engagement between the ascending restriction roller 41 of the third rotating arm 35 of each link mechanism 32 and each regulated member 43 of the elevating table 9 is released, and the elevating operation restriction of the elevating table 9 is released. As a result, the lifting table 9 is raised by the weight of the balance weight 30. Then, immediately before the elevating table 9 reaches the ascending end position, the lowering restricting rollers 17 of the first rotating arms 14 are operated by the respective regulated members 12 of the elevating table 9, whereby each first 5 is rotated in the counterclockwise direction in FIG. 5 around each first rotation shaft 13. Further, when each regulated member 12 passes through each descending regulation roller 17, each first rotation arm 14 is rotated around each first rotation shaft 13 in the clockwise direction in FIG. Returning to the position, the lowering restricting roller 17 of each first rotating arm 14 is brought into contact with the lower surface of each regulated member 12, so that the lowering operation of the lifting table 9 that has reached the rising end position is restricted. The

This embodiment has the following effects.
In the tray return device 1, the tray 2 on which the workpiece 3 is placed is supplied to the tray delivery path 5 on the lifting table 9 that is positioned and held at the rising end position by the lowering movement restricting means. Then, by using the difference in weight between the tray 2 on which the work 3 is placed and the tray 2 that has been emptied after the work 3 is taken out, the descent operation restriction release means is activated, and the empty tray 2 is placed. The lifting table 9 is lowered against the weight of the balance weight 30. Further, when the lifting table 9 reaches the lower end position, the ascending operation restricting means becomes effective, the lifting table 9 is positioned and held at the lower end position, and the empty tray 2 is moved from the tray delivery path 5 to the tray return path. 6 is moved. Then, when the link mechanism 32 is operated by the empty tray 2 moving on the tray return path 6, the lifting operation restriction canceling means is operated, and the lifting table 9 from which the tray 2 is carried out is lifted by the weight of the balance weight 30. Is done. Further, when the lifting table 9 reaches the rising end position, it is positioned and held at the rising end position by the lowering movement restricting means.

  Therefore, the tray return device 1 does not require an actuator such as an air cylinder or an electric motor, and a control device associated with the actuator, and can be simplified and reduced in size as compared with a device requiring a conventional actuator. Become. As a result, the tray return apparatus 1 can be reduced in equipment costs and maintenance costs, and can be moved and maintained easily because a driving source such as an air source and a power source is unnecessary. Further, in the present tray return apparatus 1, the tray 2 from which the workpiece 3 has been taken out is automatically and promptly returned and the next tray 2 on which the workpiece 3 is placed is automatically and promptly supplied. It is done. Further, there is no need to operate a switch such as a push button switch or a foot switch, and the weight difference between the tray 2 on which the work 3 is placed and the tray 2 that has been emptied after the work 3 is taken out is detected. Since the tray 2 is automatically returned, the operator can take out the workpiece 3 from the tray 2 with both hands, and work efficiency and work safety can be improved.

It is a general view of this tray return apparatus. It is a top view of this tray return apparatus. It is explanatory drawing of this tray return apparatus, Comprising: It is a figure which shows the state immediately before the tray which mounted the workpiece | work in particular is supplied to a tray delivery path. It is explanatory drawing of this tray return apparatus, Comprising: It is a figure which shows the state in which the tray detection part of the 2nd rotation arm was especially pushed in by the tray which mounted the workpiece | work. It is explanatory drawing of this tray return apparatus, Comprising: It is a figure which shows the state by which the raising / lowering table was positioned and hold | maintained in the falling end position especially. It is explanatory drawing of this tray return apparatus, and it interlock | cooperates with rotation operation | movement of this 2nd rotation arm especially, when the tray which was emptied after the workpiece | work was taken out is pushed back by the 2nd rotation arm. It is a figure which shows the structure where a 1st rotation arm is rotated and a descent | fall operation | movement control means is cancelled | released. It is explanatory drawing of this tray return apparatus, Comprising: It is a figure for demonstrating especially operation | movement of a descent | fall control action cancellation | release means. It is explanatory drawing of this tray return apparatus, Comprising: It is a figure for demonstrating operation | movement of a link mechanism especially.

Explanation of symbols

  1 tray return device, 2 trays, 3 workpieces, 4 tray supply passages, 5 tray delivery passages, 6 tray return passages, 7 body frame (device body), 9 lift table, 12 restricted member (downward movement restricting means), 13 1st rotation axis, 14 1st rotation arm, 17 descent | fall control roller (descent | fall operation | movement control means), 19 2nd rotation axis | shaft, 20 2nd rotation arm, 26 descent | fall restriction release lever (down movement) (Regulation release means), 27 descent restriction release roller (down movement restriction release means), 29 fixed pulley, 30 balance weight, 31 chain member, 32 link mechanism (upward movement restriction means, up movement restriction release means), 34 third Rotating shaft, 35 3rd rotating arm, 36 4th rotating shaft, 37 4th rotating arm, 38 杆 member

Claims (4)

A tray return device in which a tray on which a workpiece is placed is provided in a workpiece conveyance line supplied by a tray supply path, and the tray that is emptied after the workpiece is taken out is returned,
A tray return path that is installed below the tray supply path and transports the tray that has been emptied by taking out the workpiece; and a lifting table that can move up and down between the tray return path and the tray supply path. The lift table is provided on the lift table and is connected to the tray supply path when the lift table is positioned at the rising end position, and the tray return path is positioned when the lift table is positioned at the lower end position. The tray transfer path to be connected, the lowering operation restricting means for restricting the lowering operation of the lifting table located at the rising end position, and the work is taken out from the tray supplied to the tray transfer path by the tray supply path. A workpiece take-out sensing means for sensing that the tray has been placed on the tray delivery path by the workpiece take-out sensing means. The lowering movement restriction releasing means for releasing the restriction of the lowering movement of the lifting table by the lowering movement restricting means by sensing that the workpiece has been taken out, and the lifting table positioned at the lower end position. Ascending operation restricting means for restricting the ascending operation, tray unloading sensing means for sensing that the tray has been carried out from the tray delivery path to the tray return path, and the tray unloading sensing means for causing the tray to move to the tray. An ascending operation restriction releasing means for releasing the restriction of the lifting operation of the lifting table by the ascending action restricting means upon sensing that the tray has been carried out from the delivery path to the tray return path, and an apparatus body. A chain that is engaged with a fixed pulley, one end of which is connected to the lifting table and the other end is suspended from a balance weight. And comprising: a down member,
The balance weight has the tray on which the work is taken out and the tray is emptied by releasing the lowering restriction of the lifting table by the lowering action restricting means by the lowering action restriction releasing means. The lifting table is lowered, and the lifting operation restriction of the lifting table by the lifting action restriction means is released by the lifting action restriction releasing means, whereby the lifting table after the tray is carried out is raised. As described above, the tray return device is characterized in that the weight is set. The lowering operation restricting means is provided so as to be rotatable around a first rotating shaft provided in the apparatus main body, and the upper and lower tables are supported by the upper end and the lower end is restricted, and the rotating operation is restricted. A first pivot arm that is pivotable about a second pivot shaft provided in the apparatus main body, an upper end protruding into the tray delivery path and a lower end of the first pivot arm. A second pivoting arm engageable with the upper end of the pivoting arm,
The lowering operation restriction release means is configured such that the second rotation arm is rotated around the second rotation axis by the tray supplied to the tray delivery path, and is placed on the tray. When the workpiece is taken out, the tray is pushed back by the weight of the second rotating arm, and the upper end of the first rotating arm is operated by the lower end of the second rotating arm. The tray return device according to claim 1, wherein the pivot arm is configured to be pivoted about the first pivot axis to release the descending movement restricting means. The ascending motion restricting means is formed in an L shape and is pivotable around a third pivot shaft provided in the apparatus main body, and has one end engageable with the lift table. A third rotating arm whose other end is restricted and its turning operation is restricted; and an L-shaped arm that is rotatable around a fourth turning shaft provided in the apparatus main body. A fourth pivoting arm having one end protruding into the tray return path, one end pivotably connected to the other end of the fourth pivoting arm, and the other end pivoting to the third pivoting arm. A hook member rotatably connected to a predetermined portion near the other end of the arm,
The ascending restriction release means is configured such that the third rotating arm is moved by rotating the fourth rotating arm around the fourth rotating shaft by the tray traveling on the tray return path. The tray return device according to claim 1 or 2, wherein the link mechanism is configured so as to be rotated around the third rotation axis to release the ascending operation restricting means. A method of returning a tray that has been emptied after a workpiece is taken out on a workpiece transfer line,
The removal of the work from the tray is sensed by a weight difference between the tray on which the work is placed and the tray that is empty after the work is taken out, and then the empty The elevator table on which the tray is placed is lowered by using the weight difference and held at the lower end position, and then the empty tray is carried out to the tray return path to return the empty tray. Then, using the difference in weight between the state in which the tray that has been emptied is placed and the state after the tray is unloaded, the lifting table after the tray is unloaded is raised. Tray return method characterized by letting you.

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