Conveyance device and conveyance method using the same

Abstract

To provide a conveyance device and a conveyance method capable of shortening the return process of an available conveyance tool while pulling an article to be conveyed using a conveyor chain and utilizing a structure for conveying the article.SOLUTION: This conveyance device includes a conveyor chain 4 of an endless track installed between chain wheels 10 and 14 of a driving unit 2 and a driven unit 3. Conveyance tools 5 are respectively attached to symmetrical positions bisecting the endless track on the outgoing and returning sides of the conveyor chain 4, and movable positioning stoppers 17 and 18 which can stop / pass the conveyance tools 5 are provided on the carrying-in and carrying-out sides of the article. The conveyance tools 5 are structured so as not to block bending of the conveyor chain 4 on the driving and driven units.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a conveying device in which a conveyor chain is stretched between a drive unit and a driven unit of chain wheels, and a conveying method using the same. [Background technology]

[0002] For example, in a casting molding line, a conveyor chain is stretched between a drive unit and a driven unit of chain wheels as a means for conveying a surface plate cart carrying a mold, and the conveyor chain is switched in the moving direction to move the surface plate cart back and forth between a carry-in position and a carry-out position to be conveyed (Patent Document 1, Patent Document 2). An example of such a conventional conveyor device 101 is shown in Figs. 9 and 10.

[0003] In these figures, the driving unit 102 has a driving shaft 111 driven by a reduction motor 113 and a drive chain 112. The driven unit 103 has a driven shaft 115 pulled by a take-up 116. A conveyor chain 104 is stretched between a chain wheel 110 fixed to the driving shaft 111 and a chain wheel 114 attached to the driven shaft 115, forming a transport unit 106. A transport jig 105 for transporting an object 7 is attached to the conveyor chain 104. Fixed stoppers 117 and 118 are provided on the carry-out side 108 and the carry-in side 109, respectively, to regulate the stopping positions of the transport jig 105.

[0004] The article 7 is placed on the transport jig 105 at the carry-in side 109, and is transported to the carry-out side 108 by driving the conveyor chain 104. After the transport jig 105 has been emptied of the article 7, it is returned to the carry-in side 109 by driving the conveyor chain 104 in the reverse direction. A transport device with such a structure has the advantage that it is not affected by elongation of the conveyor chain 104 due to aging, since the stopping position of the transport jig 105 can be regulated by the fixed positioning stoppers 117, 118.

[0005] Also, compared to a self-propelled transport jig, there is no need to consider the coefficient of friction between the wheels and rails, so acceleration and deceleration can be performed without slipping, making it possible to increase speed, and there is no need to mount a motor on the transport jig 105, so there is no need for a Cableveyor (registered trademark), and the structure can be simplified. However, there is a problem in that the transport jig 105 is moved back and forth on the way there and back, and the empty transport jig is returned to its original position on the way back, which creates a waste of time in the way back. The waste of time in the way back is the same when a self-propelled transport jig is used. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2015-13697 A [Patent Document 2] Patent No. 3620629 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a conveying device and a conveying method using the same that make use of a structure for conveying objects using a conveyor chain and can shorten the return process of an empty conveying jig. [Means for solving the problem]

[0008] The present invention, which has been made to solve the above problems, is a conveying device in which an endless track conveyor chain is suspended between a drive unit and a driven unit of chain wheels, and is characterized in that conveying jigs for carrying objects to be conveyed are attached to symmetrical positions that divide the endless track of the conveyor chain in half, and movable positioning stoppers that can stop and allow the conveying jigs to pass are provided on the loading side and the unloading side, respectively.

[0009] The transport jig must have a structure that does not impede bending of the conveyor chain at the driving section and the driven section. Also, the transport jig is preferably provided with a structure that distributes and applies the load of the mold to a plurality of rollers of the conveyor chain.

[0010] The transported object may be a surface plate cart carrying a mold.

[0011] In addition, the conveying method of the present invention, which has been devised to solve the above-mentioned problems, uses the above-mentioned conveying device, loads the object to be conveyed onto one of the conveying jigs attached at a symmetrical position that divides the endless track in half at an entrance position, and drives the conveyor chain to convey the object to an exit position, while simultaneously moving the other conveying jig via the back side of the conveyor chain to a waiting position just before the entrance position, and then drives the conveyor chain further to stop the other conveying jig at the entrance position, repeating this cycle.

[0012] The transport jig can be stopped at the carry-in position and the carry-out position by movable positioning stoppers provided on the carry-in side and the carry-out side. Effect of the Invention

[0013] According to the present invention, an endless track conveyor chain is used that is stretched between the chain wheels of the drive unit and the driven unit, and an object to be transported is loaded on one of the transport jigs attached to the conveyor chain, and transported from the carry-in position to the carry-out position. The transport jig is not affected by the stretching of the conveyor chain, because the stop position is regulated by a movable positioning stopper. Moreover, in parallel with the transport by one of the transport jigs, the other transport jig that has become empty can be moved to a standby position just before the carry-in position via the back side of the conveyor chain. This makes it possible to shorten the time required for the return process of the empty transport jig, thereby shortening the transport process time. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a front view of the transport device according to the first embodiment. [Diagram 2] FIG. 2 is a plan view of the transport device according to the first embodiment. [Diagram 3] 2 is an enlarged front view of a portion of the transported object on the carry-in side of the first embodiment. FIG. [Figure 4] 3 is an enlarged front view of a portion of the transported object on the discharge side in the first embodiment. FIG. [Diagram 5] 2 is a partially cutaway side view of the loading side portion (a cross-sectional view taken along the line AA in FIG. 1). [Figure 6] 1. FIG. 4 is a partially cutaway side view of the unloading side portion (a cross-sectional view taken along the line BB in FIG. 1). [Figure 7a] FIG. [Figure 7b] FIG. 13 is a front view showing the positioning stopper alone in a closed state. [Figure 7c] FIG. 13 is a front view showing the positioning stopper alone in an open state. [Figure 8a] FIG. 11 is a front view showing a state in which the positioning stopper is closed when using a single conveyor chain attachment. [Figure 8b] FIG. 11 is a front view showing a state in which the positioning stopper is open when using a single conveyor chain attachment. [Figure 8c] FIG. 11 is a front view showing a state in which the positioning stopper is closed when the conveyor chain double attachment is used. [Figure 8d] FIG. 11 is a front view showing a state in which the positioning stopper is open when the conveyor chain double attachment is used. [Figure 9] FIG. 1 is a front view of a prior art conveying device. [Figure 10] FIG. 1 is a plan view of a prior art conveying device. [Figure 11] 1 is a diagram showing a conveying process of a conveying device of the present invention and a conveying device of a related art; [Figure 12] FIG. 11 is a front view of a transport device according to a second embodiment capable of receiving a heavy load. [Figure 13] FIG. 11 is a plan view of a transport device according to a second embodiment. [Figure 14] FIG. 11 is an enlarged front view of a carry-in side portion of a transport device according to a second embodiment. [Figure 15] FIG. 11 is an enlarged front view of a discharge side portion of a transport device according to a second embodiment. [Figure 16] 13 is a partially cutaway side view of the loading side portion (a cross-sectional view taken along the line CC in FIG. 12). [Figure 17] 13 is a partially cutaway side view of the unloading side portion (a cross-sectional view taken along the line DD in FIG. 12). FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] An embodiment of the present invention will be described below. As shown in Figs. 1 to 6, a conveying device 1 of the present invention includes a conveying section 6 composed of a driving section 2, a driven section 3, and a conveying jig 5 attached to two places of a conveyor chain 4, and conveys an object 7. As shown in Figs. 3 and 4, the object 7 in this embodiment is a surface plate carriage 7b carrying a mold 7a. In general, the driving section 2 is disposed on the carry-out side 8 of the object 7, and the driven section 3 is disposed on the carry-in side 9. As will be described below, the object 7 is mounted on the conveying jig 5 and conveyed from the carry-in side 9 to the carry-out side 8.

[0016] As shown in Fig. 4, the driving unit 2 is structured to rotate a driving wheel 11, to which a chain wheel 10 is attached, by a reduction motor 13 via a drive chain 12. Also, as shown in Fig. 3, the driven unit 3 is structured to pull a driven shaft 15, to which a chain wheel 14 is attached, by a take-up 16 to take up slack in the stretched conveyor chain 4. Between the chain wheel 10 of the driving unit 2 and the chain wheel 14 of the driven unit 3, the endless track conveyor chain 4 is stretched.

[0017] As shown in Fig. 5, a carry-in device (not shown) is provided on the carry-in side 9 of the transported article 7, and carries in the transported article 7 from a direction perpendicular to the transport direction. Also, as shown in Fig. 6, a carry-out device (not shown) is provided on the carry-out side 8, and carries out the transported article 7 from a direction perpendicular to the transport direction. The carry-in position 30 and the carry-out position 31 of the transported article 7 are shown in Figs. 1 to 4.

[0018] In the present invention, the transport jigs 5a and 5b are attached to symmetrical positions that divide the endless track of the conveyor chain 4 into two equal parts. In the first embodiment shown in Figs. 1 to 6, the transport jig 5a has a structure in which a pair of separate parts 5a1 and 5a2 are attached to the links 4a and 4b of the conveyor chain 4 as shown in Fig. 3, and is structured so as not to hinder the bending of the conveyor chain 4 at the driving part 2 and the driven part 3. The links 4a and 4b are on both the left and right sides, and each link has two rollers at the front and back, so that the load of the transported object 7 placed on the transport jig 5a is distributed to a total of eight rollers. In this way, the structure is such that the load of the transported object 7 is distributed and applied to the multiple rollers of the conveyor chain 4, so that the wear of the rollers can be reduced.

[0019] The other transport jig 5b has the same structure as the transport jig 5a. When one transport jig 5a is at the position of the carry-in side 9 shown in Fig. 3, the other transport jig 5b is at the back side (lower side) of the carry-out side 8 of the conveyor chain 4 as shown in Figs. 1 and 4. In this way, the pair of transport jigs 5a, 5b are always located in point-symmetrical positions with respect to the center of the endless track, and when one is on the outward side of the conveyor chain 4, the other is on the return side.

[0020] In the second embodiment shown in Figs. 12 to 17, the transport jigs 5c and 5d have an integrated structure capable of bearing a heavy load. The transport jigs 5c and 5d are attached to one link 4c at their centers, and as shown in Figs. 14 and 15, the structure does not hinder the bending of the conveyor chain 4 in the driving unit 2 and the driven unit 3. As shown in Figs. 14 and 15, the transport jigs 5c and 5d are provided with adjustment bolts 26 at the front and rear, and when the transported object 7 is placed on the transport jig 5c, the lower surface of the transport jigs 5c and 5d is supported by the front and rear links 4d and 4e via the adjustment bolts 26 in addition to the central link 4c. That is, the load is distributed to three links at the front and rear, and six links on both sides, and each link has two rollers at the front and rear, so that the load of the transported object 7 placed on the transport jigs 5c and 5d is distributed to a total of 12 rollers. When the transported object 7 is carried into the transport jigs 5c and 5d, the adjustment bolts 26 come into contact with the links 4d and 4e, thereby enabling stable transport of the transported object 7. As shown in Fig. 14 and Fig. 15, the transport jigs 5c and 5d of the second embodiment are also always positioned point-symmetrically with respect to the center of the endless track.

[0021] In order to stop these transport jigs 5 accurately at the carry-in position 30 and the carry-out position 31 even if the conveyor chain 4 is stretched, movable positioning stoppers 17, 18 that can stop and allow the transport jigs 5 to pass are provided on the carry-in side 9 and the carry-out side 8 of the transported goods 7, respectively. The positioning stoppers 17, 18 have a structure in which an arm 22 with a stopper bolt 21 attached to the tip is attached to a shaft 24 penetrating a bearing 23 as shown in Fig. 7, and the arm 22 is swung by a cylinder 25.

[0022] Since the parallelism between a pair of transport jigs 5a1, 5a2 attached to the conveyor chain 4 changes due to the elongation of the chain, the position of the transported item 7 is determined by using the transport jig 5a2 on the side that is in contact with the stopper 18 or 17 as a reference, and the wheels of the transport cart placed on the transport jig 5a2 side as both flanges, and the wheels of the transport cart for the transported item 7 placed on the transport jig 5a1 side, whose pitch and parallelism change due to the elongation of the chain, are made flangeless.

[0023] Figures 8a and 8b show the operation of the positioning stoppers 17 and 18 when a single conveyor chain attachment is used, and Figures 8c and 8d show the operation of the positioning stoppers when a double conveyor chain attachment is used. Figures 8a and 8c show the state in which the arm 22 lowers the stopper bolt 21 to stop the transport jig 5, and Figures 8b and 8d show the state in which the arm 22 lifts the stopper bolt 21 to allow the transport jig 5 to pass. In this way, the positioning stoppers 17 and 18 can swing the arm 22 to allow the transport jig 5 to pass or stop it at a specified position.

[0024] Specifically, the method of stopping the transport jig 5 is as follows: after detecting that the transport jig 5a2 or 5b2 has arrived at the transport-out section or the load-in section using a proximity switch or the like (not shown) provided at the transport-out section or the load-in section, in order to prevent the transport jig 5a2 or 5b2 from bouncing back due to the elasticity of the conveyor chain 4 when pressed against the stopper 18 or 17, a delay timer is used to press the transport jig 5a2 or 5b2 against the stopper 18 or 17 for a certain period of time to position it, and then the brake of the reduction motor 13 is applied, and then the power to the reduction motor 13 is cut off.

[0025] Next, a method for transporting the article 7 by the transport device of the present invention will be described. First, the positioning stopper 18 installed on the carry-in side 9 is closed, one of the transport jigs 5 is stopped at the carry-in position, and the transported object 7 is transported to the transport jig 5. Next, the positioning stopper 17 installed on the carry-out side 8 is closed, the positioning stopper 18 installed on the carry-in side 9 is opened, and the conveyor chain 4 is driven to transport the transport jig 5 to the carry-out side 8 and stop it at the carry-out position. In this way, the positioning stoppers 17 and 18 can accurately regulate the stop position of the transport jig 5, so that the stop position deviation due to the stretching of the conveyor chain 4 can be prevented. In addition, when the transport jig 5 approaches the carry-in position 30 or the carry-out position 31, the deceleration motor 13 may be controlled so that the moving speed of the transport jig 5 is decelerated. This makes it possible to suppress damage to the transported object 7 caused by the impact when the transport jig 5 stops.

[0026] While one transport jig 5a moves from the carry-in position 30 to the carry-out position 31, the other transport jig 5b moves along the back side of the conveyor chain 4 to a standby position just before the carry-in position 30. After the transported object 7 is carried out at the carry-out side 8, the positioning stopper 17 at the carry-out side 8 is opened, and the positioning stopper 18 installed at the carry-in side 9 is closed. After that, the conveyor chain 4 is driven further in the same direction, and the other transport jig 5b is stopped at the carry-in position by the positioning stopper 18. The same cycle is repeated thereafter.

[0027] In this way, according to the present invention, when one transport jig 5a is located at the unloading position 31, the other transport jig 5b has moved to the standby position just before the load position 30, and the moving distance from there to the load position 30 is short. Therefore, the moving time of the empty transport jig 5b can be made shorter than in the conventional reciprocating transport device 101 shown in Figs. 9 and 10.

[0028] FIG. 11 shows a time chart comparing the cycle time of the transport device of the present invention with that of a conventional transport device. If the time required for loading and unloading, and the time required for transport are the same, the conventional transport device has a total cycle time of 43 seconds because it takes longer to return the empty transport jig. In contrast, the transport device of the present invention can shorten the movement time of the empty transport jig, so the cycle time is 33.5 seconds, which is shortened by about 78%. In FIG. 11, the calculation is based on the transport distance of 12 m, the transport speed of 0.8 m / sec, the movement distance of the transport jig from the standby position to the loading position of 2.4 m, and the movement speed of 1 m / sec. If these values ​​change, the absolute value of the cycle time will change, but the cycle time of the transport device of the present invention will still be shorter than that of the conventional transport device.

[0029] The conveying device of the present invention has the advantage that the acceleration and deceleration can be increased to speed up the device without slipping because it is not necessary to consider the coefficient of friction between the wheels and the rails, and the conveying time can be further reduced by shortening the conveying process of the empty conveying cart. In this way, the conveying speed can be slower than that of a conventional conveying device that moves back and forth if the operating process time is the same, which contributes to the stable operation of the equipment and the long life of consumables and spare parts, thereby contributing to the SDGs. In addition, the conveying device of the present invention uses a structure in which the rollers of the conveyor chain directly bear the load, making it possible to eliminate the need for wheels on the conveying jig.

[0030] Furthermore, recent technological innovations have made it possible to adopt conveyor chains that use bearings to connect the links. Compared to conventional conveyor chains that use pins and bushes to connect the links, this allows for reduced power consumption due to reduced running resistance, longer life for the conveyor chain due to reduced wear on the links, and a smaller size for the conveyor chain due to increased load capacity that the rollers of the conveyor chain can withstand.

[0031] Specifically, the load capacity of a conveyor chain using bearings to connect links and a conventional conveyor chain using pins and bushes to connect links is 10-14kN for the bearing specification and 4-8kN for the pin bush specification when the chain size is RF17, so the bearing specification has about twice the load capacity. Also, the difference in friction coefficient is 0.03 for the bearing specification and 0.08-0.14 for the pin bush specification when the roller diameter is 65mm to 100mm, so the bearing specification can reduce the friction coefficient to about 1 / 4. Therefore, by using a conveyor chain with bearing specifications, it is possible to further enhance the effects of the present invention.

[0032] In the above embodiment, the transported object 7 is the surface plate cart 7b carrying the mold 7a, but what is loaded onto the surface plate cart 7b is not limited to the mold, and may be a carrier plate, a weight, a pallet, a work (e.g., casting, cast product), etc. Furthermore, as long as it can be carried in by a carry-in device and carried out by a carry-out device, the surface plate cart 7b is not essential, and the transported object 7 may be one that is not loaded onto a surface plate cart. In this way, the present invention can be widely used for transporting various transported objects. [Explanation of symbols]

[0033] 1. The conveying device of the present invention 2 Drive unit 3 Driven part 4 Conveyor Chain 5. Transport fixture 6. Conveyor 7a Mold 7b Surface plate cart 7. Transport items 8. Unloading side 9. Loading side 10 Chain Wheel 11 Drive wheels 12 Drive Chain 13 Reduction motor 14 Chain Wheel 15 Driven axis 16 Take Up 17 Movable positioning stopper 18 Movable positioning stopper 21 Stopper bolt 22 Arm 23 Bearings 24 Axis 25 cylinders 26 Adjusting bolt 30 Loading position 31 Unloading position 101 Conventional reciprocating conveying device 102 Drive unit 103 Driven part 104 Conveyor Chain 105 Transport fixture 106 Conveyor 108 Unloading side 109 Loading side 110 Chain Wheel 111 Drive shaft 112 Drive Chain 113 Reduction motor 114 Chain Wheel 116 Take Up 115 Driven axis 117 Fixed stopper 118 Fixed stopper

Claims

1. A conveying device in which an endless track conveyor chain is stretched between a drive part and a driven part of a chain wheel, A conveying jig for carrying an object is attached to each of symmetrical positions that divide the endless track of the conveyor chain into two equal parts, A conveying device in which movable positioning stoppers capable of stopping and passing the conveying jig are provided on the carry-in side and the carry-out side, respectively.

2. 2. The conveying device according to claim 1, wherein the conveying jig is structured so as not to hinder bending of the conveyor chain at the driving section and the driven section.

3. 3. The conveying device according to claim 1, wherein the conveying jig has a structure for distributing and applying a load of the conveyed object to a plurality of rollers of the conveyor chain.

4. 3. The conveying device according to claim 1, wherein the article to be conveyed is a surface plate carriage on which a mold is mounted.

5. A conveying method using the conveying device according to claim 1, The transport method involves loading an item at a loading position onto one of the transporting jigs attached at a symmetrical position dividing the endless track in two, driving the conveyor chain to transport it to an unloading position, and simultaneously moving the other transporting jig via the back side of the conveyor chain to a waiting position just before the loading position, and then further driving the conveyor chain to stop the other transporting jig at the loading position, repeating this cycle.

6. 6. The transport method according to claim 5, wherein the transport jig is stopped at the carry-in position and the carry-out position by movable positioning stoppers provided on the carry-in side and the carry-out side.

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