Variable-pitch double-layer pallet fork mechanism

Abstract

The invention discloses a variable-pitch double-layer pallet fork mechanism, and relates to the technical field of pallet forks. The equipment comprises an equipment shell, a double-layer frame is fixed in the equipment shell, fork devices are arranged on the two sides of the two layers of the double-layer frame, and each fork device comprises two U-shaped guide rails fixed to the top of a layer plate of the double-layer frame and two sliding plates slidably installed in the two U-shaped guide rails correspondingly. A first pallet fork arm, a second pallet fork arm and a third pallet fork arm are sequentially arranged on the sides, close to the center of the double-layer frame, of the two sliding plates, and a plurality of bearing wheels are evenly and rotationally installed on the outer wall of the first pallet fork arm and the outer wall of the second pallet fork arm at equal intervals. Through the arrangement of the pallet fork device, the function that only the middle turnover box is taken from a whole stack is achieved, the requirement for taking the middle turnover box from a single stack of products is met, a large amount of turnover time is saved, the number of layers of goods shelves can be reduced within the load range through the material taking mode of lifting flanges of the turnover boxes, and the utilization rate of the site space is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of forklift forks, and particularly to a variable pitch double-layer forklift fork mechanism. Background Art

[0002] Automatic material handling forklift forks are extremely widely used in the intelligent warehousing industry. With the continuous change of market demand, the requirements for forklift forks are also constantly updated. Automatic material handling forklift forks are a kind of equipment for material handling through an automated control system. It reduces manual operation, improves work efficiency, and can adapt to complex working environments, with high automation, precision and safety, and is especially suitable for efficient and precise warehouse management and material distribution.

[0003] However, most of the current forklift forks are for one-time whole picking of single-layer or single-pallet products. If there are multiple bins stacked on a stack of products and only the middle bin needs to be picked, it is relatively complex to implement the single forklift fork mode. Therefore, we propose a variable pitch double-layer forklift fork mechanism. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a variable pitch double-layer forklift fork mechanism, which solves the problems raised in the above background art.

[0005] To achieve the above object, the present invention is realized through the following technical solutions: A variable pitch double-layer fork mechanism, including an equipment housing, inside which a double-layer rack is fixed. On both sides of the two layers of the double-layer rack, there are fork devices. The fork device includes two U-shaped guide rails fixed on the top of the double-layer rack laminate, two sliding plates respectively installed inside the two U-shaped guide rails. On one side of the two sliding plates close to the center of the double-layer rack, there are successively a fork arm one, a fork arm two, and a fork arm three. On the outer walls of the fork arm one and the fork arm two, a number of bearing wheels are evenly and equidistantly rotatably installed. The number of bearing wheels corresponding to the fork arm one is used to guide and support the fork arm two, and the number of bearing wheels corresponding to the fork arm two is used to guide and support the fork arm three. The fork arm one, the fork arm two, and the fork arm three are driven by a conveyor chain assembly. The conveyor chain assembly is an existing device for driving the fork arm two and the fork arm three to move outwards from the fork arm one, and will not be elaborated here. Outside the fork arm one, there is a driving assembly, which is used to drive the fork arm one to move horizontally. The driving assembly includes a fixing plate, a gear sleeve, a lead screw, a toothed ring, and a servo motor. The fixing plate is fixed on the top of the double-layer rack laminate, the servo motor is fixed on the outer wall above the fixing plate, the toothed ring is fixed on the outer wall of the output end of the servo motor, the lead screw is fixed on the outer wall of the fork arm one, a round hole for the lead screw to pass through is opened on the lower outer wall of the fixing plate, the gear sleeve is rotatably installed on the outer wall of the fixing plate, and the inside of the gear sleeve is threadedly connected to the outside of the lead screw. On the top of one side of the fork arm three away from the fork arm two, a number of bearing plates are fixed. On the rear side of one side of the fork arm three away from the fork arm two, an electric push rod is fixed. On the front side of one side of the fork arm three away from the fork arm two, an elastic telescopic rod one is fixed. Between the telescopic ends of the electric push rod and the elastic telescopic rod one, a top plate is fixed. On the top of the top plate, a number of cushion blocks are fixed. The cushion blocks penetrate the bottom of the bearing plate, and the tops of the cushion blocks are at the same horizontal plane as the tops of the bearing plates. When there are multiple turnover boxes stacked on a stack of products and only the middle turnover box needs to be taken, the conveyor chain assemblies of the two layers respectively drive the fork arm two and the fork arm three of the two layers to move outwards from the fork arm one until the fork arm three of the two layers moves to the position of the turnover box, and the fork arm three drives the bearing plate to move to the flange edge of the turnover box. Then, first start the electric push rod of the upper layer. The telescopic end of the electric push rod of the upper layer pushes the top plate to drive the cushion block to move upwards. The cushion block of the upper layer jacks up the upper turnover box. At this time, the upper turnover box is separated from the lower turnover box up and down, and the upper turnover box is no longer stacked on the lower turnover box (the turnover box to be taken out). Then, start the electric push rod of the lower layer. The telescopic end of the electric push rod of the lower layer pushes the top plate to drive the cushion block to move upwards. The cushion block of the lower layer jacks up the lower turnover box (the turnover box to be taken out). Then, the conveyor chain assembly of the lower layer drives the fork arm two and the fork arm three of the lower layer to retract, and the lower turnover box (the turnover box to be taken out) is received into the double-layer rack, thus completing the picking operation of the turnover box.

[0006] According to the above technical solution, the forklift arm is provided with a limiting device at three places. The limiting device includes a U-shaped sleeve, a shaft block, and a V-shaped limiting rod. The shaft block is fixed to the front side of the third forklift arm. The middle of the V-shaped limiting rod is hinged to the bottom of the shaft block. A U-shaped rod is fixed to the bottom of the side of the V-shaped limiting rod close to the second forklift arm. The U-shaped sleeve is fixed to the side of the third forklift arm close to the second forklift arm. A resisting rod is slidably installed inside the U-shaped sleeve. A spring is provided between the rear side of the resisting rod and the outer wall of the U-shaped sleeve. A sliding column is fixed to the bottom of the front side of the resisting rod. The sliding column is slidably installed inside the U-shaped rod. The rear side of the resisting rod abuts against the inner wall of the equipment housing. After the second and third forklift arms are unfolded and moved from the first forklift arm each time, when the third forklift arm drives the resisting rod to move along with the U-shaped sleeve, the resisting rod does not abut against the inner wall of the equipment housing at this time. Under the elastic force between the resisting rod and the U-shaped sleeve, the resisting rod pops out from the U-shaped sleeve, and the resisting rod drives the sliding column to move backward. The sliding column slides along the U-shaped rod, and the sliding column pulls the U-shaped rod to drive the V-shaped limiting rod to swing (from the state where the V-shaped limiting rod is at a 90-degree angle with the third forklift arm to the state where the V-shaped limiting rod is horizontal with the third forklift arm), so that the V-shaped limiting rod does not form an obstruction at the third forklift arm. After the third forklift arm finishes picking up the goods and retracts, the third forklift arm drives the resisting rod to abut against the inner wall of the equipment housing again through the U-shaped sleeve. The resisting rod drives the sliding column to push the U-shaped rod to drive the V-shaped limiting rod to swing (from the state where the V-shaped limiting rod is horizontal with the third forklift arm to the state where the V-shaped limiting rod is at a 90-degree angle with the third forklift arm), and the V-shaped limiting rod re-forms an obstruction at the third forklift arm.

[0007] According to the above technical solution, a stacking device is provided at the equipment housing. The stacking device includes two Z-shaped rods and a U-shaped pushing plate. The two Z-shaped rods are respectively fixed to the bottom of the rear sides of the two second forklift arms on both sides. The U-shaped pushing plate is slidably installed at the bottom of the double-layer rack. Sliders are slidably installed on both sides of the rear side of the U-shaped pushing plate. Springs are provided between the sliders and the front sides of the outer walls below the Z-shaped rods. Positioning columns are fixed to the rear sides of the sliders, and the two positioning columns respectively penetrate the outer walls below the two Z-shaped rods. The front side of the U-shaped pushing plate is on the same horizontal plane as the front side of the equipment double-layer rack. Each time the second forklift arm is unfolded and moved from the first forklift arm, the second forklift arm drives the U-shaped pushing plate to move along with the Z-shaped rods, the sliders, and the springs corresponding to the sliders until the U-shaped pushing plate abuts against the outer wall of the turnover box below the lower turnover box (the turnover box to be taken out). As the second forklift arm drives the Z-shaped rod to continue to move, since the U-shaped pushing plate has already abutted against the outer wall of the lower turnover box, the U-shaped pushing plate will no longer move, while the Z-shaped rod moves along the outside of the positioning column and leans towards the U-shaped pushing plate. Under the elastic force of the spring corresponding to the slider, the slider can push the U-shaped pushing plate to closely adhere to the outer wall of the lower turnover box.

[0008] According to the above technical solution, the stacking device further includes two second elastic telescopic rods and two L-shaped telescopic column rods. The fixed ends of the two second elastic telescopic rods are respectively slidably installed on both sides of the bottom of the U-shaped push plate. On one side of the telescopic ends of the two second elastic telescopic rods that are away from each other, an L-shaped side blocking column is fixed. On the rear side below the two L-shaped side blocking columns, a Z-shaped track groove plate is fixed. A Z-shaped groove is opened at the top of the Z-shaped track groove plate. The two L-shaped telescopic column rods are respectively fixed on one side of the outer walls of the lower parts of the two Z-shaped rods that are away from each other. The end of the L-shaped telescopic column rod away from the Z-shaped rod is slidably installed inside the Z-shaped groove of the Z-shaped track groove plate. A spacing of fifty centimeters is left between the vertical columns of the two L-shaped side blocking columns and the front side of the double-layer rack. The two L-shaped side blocking columns are respectively located on both sides of the U-shaped push plate. When the Z-shaped rod moves along the outside of the positioning column and approaches the U-shaped push plate, the Z-shaped rod drives the L-shaped telescopic column rod to move along. The L-shaped telescopic column rod slides inside the Z-shaped groove of the Z-shaped track groove plate, and the L-shaped telescopic column rod pushes the Z-shaped track groove plate to drive the L-shaped side blocking column to move towards the center of the U-shaped push plate. The L-shaped side blocking column drives the second elastic telescopic rod to move along the bottom of the U-shaped push plate towards the center of the U-shaped push plate until the L-shaped side blocking column abuts against the side walls of the upper turnover box and the lower turnover box. After the lower turnover box (the turnover box to be taken out) is received into the double-layer rack, the L-shaped side blocking column and the U-shaped push plate are reset to the initial state. Then, the forklift mechanism is driven by an external lifting module to move down as a whole. At this time, the upper forklift device can place the upper turnover box lifted by the bucket on the top of the lower turnover box.

[0009] The present invention provides a variable-spacing double-layer forklift mechanism. It has the following beneficial effects: (1) Through the setting of the forklift device in the present invention, the function of only taking the middle turnover box in the whole stack is realized, which meets the requirement of taking the middle turnover box of a single-stack product, saves a large amount of turnover time, and through the material-taking method of lifting the turnover box flange, within the load range, the number of shelves can be reduced, and the utilization rate of the site space can be improved. At the same time, with the cooperation of the servo motor, the tooth ring, the gear sleeve, and the lead screw, the distance between the two forklift devices on both sides can be adjusted to adapt to turnover boxes of different models.

[0010] (2) Through the setting of the limiting device in the present invention, after the forklift arm three finishes taking goods and retracts, the forklift arm three, the U-shaped sleeve, the abutting rod, the equipment shell, the sliding column, and the U-shaped rod cooperate to drive the V-shaped limiting rod to swing. The V-shaped limiting rod forms a new block at the forklift arm three. The blocking effect of the V-shaped limiting rod can prevent the turnover box from shifting in the horizontal state of the forklift arm three. Especially when transporting the turnover box, it effectively prevents the goods from sliding or falling during the handling process, ensuring the safety of the goods in the turnover box.

[0011] (3) With the stacking device provided in the present invention, every time the second fork arm unfolds and moves from the first fork arm, the second fork arm, the Z-shaped rod, the slider, and the slider cooperate to drive the U-shaped push plate to closely adhere to the outer wall of the turnover box below, so that the fork mechanism of the present invention can stably grasp the lower turnover box during the object-taking process, avoiding the tilting or dropping of items caused by inaccurate docking between the lower turnover box and the turnover box below; at the same time, the Z-shaped rod, the positioning column, the U-shaped push plate, the L-shaped telescopic column rod, and the Z-shaped track groove plate cooperate to drive the L-shaped side baffle column to abut against the side walls of the upper turnover box and the turnover box below. The L-shaped side baffle column can correct the positions of the upper turnover box and the turnover box below, so that the L-shaped side baffle column can effectively prevent the fork mechanism of the present invention from tilting excessively when placing the turnover box. Especially when placing the upper turnover box, the problem of misalignment between the upper turnover box and the turnover box below can be avoided, thereby improving the safety of the entire operation process. Description of the Drawings

[0012] Figure 1 Schematic diagram of the whole of the present invention Figure 1 ; Figure 2 Schematic diagram of the whole of the present invention Figure 2 ; Figure 3 Schematic diagram of the whole of the present invention Figure 3 ; Figure 4 Schematic diagram of the fork device of the present invention Figure 1 ; Figure 5 Schematic diagram of the fork device of the present invention Figure 2 ; Figure 6 Schematic diagram of the limiting device of the present invention Figure 1 ; Figure 7 Schematic diagram of the limiting device of the present invention Figure 2 ; Figure 8 Schematic diagram of the stacking device of the present invention Figure 1 ; Figure 9 Schematic diagram of the stacking device of the present invention Figure 2 .

[0013] In the figure: 1, equipment housing; 2, double-layer rack; 3, forklift device; 31, U-shaped guide rail; 32, slide plate; 33, first forklift arm; 34, second forklift arm; 35, third forklift arm; 36, bearing wheel; 37, drive assembly; 371, fixing plate; 372, gear sleeve; 373, lead screw; 374, toothed ring; 375, servo motor; 38, bearing plate; 39, electric push rod; 310, top plate; 311, first elastic telescopic rod; 312, cushion block; 4, limiting device; 41, abutting rod; 42, U-shaped sleeve; 43, U-shaped rod; 44, sliding column; 45, V-shaped limiting rod; 46, shaft block; 5, stacking device; 51, Z-shaped rod; 52, positioning column; 53, slider; 54, U-shaped push plate; 55, second elastic telescopic rod; 56, L-shaped side stop column; 57, Z-shaped track groove plate; 58, L-shaped telescopic column rod. Detailed implementation manner

[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0015] Please refer to Figures 1 - 9, the present invention provides a technical solution: a variable pitch double-layer fork mechanism, including an equipment housing 1. Inside the equipment housing 1, a double-layer rack 2 is fixed. On both sides of the two layers of the double-layer rack 2, fork devices 3 are provided. The fork device 3 includes two U-shaped guide rails 31 fixed on the top of the laminate of the double-layer rack 2, and two slide plates 32 slidably installed inside the two U-shaped guide rails 31 respectively. On the side of the two slide plates 32 close to the center of the double-layer rack 2, a first fork arm 33, a second fork arm 34, and a third fork arm 35 are arranged in sequence. A number of bearing wheels 36 are rotatably installed on the outer walls of the first fork arm 33 and the second fork arm 34 at equal intervals. The number of bearing wheels 36 corresponding to the first fork arm 33 is used to guide and support the second fork arm 34, and the number of bearing wheels 36 corresponding to the second fork arm 34 is used to guide and support the third fork arm 35. The first fork arm 33, the second fork arm 34, and the third fork arm 35 are driven by a transmission chain assembly. The transmission chain assembly is an existing device used to drive the second fork arm 34 and the third fork arm 35 to expand and move from the first fork arm 33, and will not be elaborated here. An external driving component 37 is arranged on the first fork arm 33. The driving component 37 is used to drive the first fork arm 33 to move horizontally. The driving component 37 includes a fixing plate 371, a gear sleeve 372, a lead screw 373, a toothed ring 374, and a servo motor 375. The fixing plate 371 is fixed on the top of the laminate of the double-layer rack 2. The servo motor 375 is fixed on the outer wall above the fixing plate 371. The toothed ring 374 is fixed on the outer wall of the output end of the servo motor 375. The lead screw 373 is fixed on the outer wall of the first fork arm 33. A circular hole for the lead screw 373 to pass through is opened on the lower outer wall of the fixing plate 371. The gear sleeve 372 is rotatably installed on the outer wall of the fixing plate 371, and the inside of the gear sleeve 372 is threadedly connected to the outside of the lead screw 373. On the top of the side of the third fork arm 35 away from the second fork arm 34, a number of bearing plates 38 are fixed. On the rear side of the side of the third fork arm 35 away from the second fork arm 34, an electric push rod 39 is fixed. On the front side of the side of the third fork arm 35 away from the second fork arm 34, a first elastic telescopic rod 311 is fixed. A top plate 310 is fixed between the telescopic ends of the electric push rod 39 and the first elastic telescopic rod 311. A number of cushion blocks 312 are fixed on the top of the top plate 310. The cushion blocks 312 penetrate through the bottom of the bearing plate 38, and the tops of the cushion blocks 312 are on the same horizontal plane as the tops of the bearing plates 38. Through the setting of the above structure, the function of only taking the middle turnover box from the whole stack is realized, meeting the demand for taking the middle turnover box of a single stack of products, saving a large amount of turnover time. And through the material taking method of lifting the flange of the turnover box, within the load range, the number of shelves can be reduced, and the utilization rate of the site space can be improved. At the same time, the servo motor 375, the toothed ring 374, the gear sleeve 372, and the lead screw 373 cooperate to adjust the distance between the two fork devices 3 on both sides to adapt to turnover boxes of different models.

[0016] According to the above technical solution, a limiting device 4 is provided at the 35th position of the forklift arm three. The limiting device 4 includes a U-shaped sleeve 42, a shaft block 46, and a V-shaped limiting rod 45. The shaft block 46 is fixed to the front side of the forklift arm three 35. The middle part of the V-shaped limiting rod 45 is hinged to the bottom of the shaft block 46. A U-shaped rod 43 is fixed to the bottom of the side of the V-shaped limiting rod 45 close to the forklift arm two 34. The U-shaped sleeve 42 is fixed to the side of the forklift arm three 35 close to the forklift arm two 34. A contact rod 41 is slidably installed inside the U-shaped sleeve 42. A spring is provided between the rear side of the contact rod 41 and the outer wall of the U-shaped sleeve 42. A sliding column 44 is fixed to the bottom of the front side of the contact rod 41. The sliding column 44 is slidably installed inside the U-shaped rod 43. The rear side of the contact rod 41 abuts against the inner wall of the equipment housing 1. Through the setting of the above structure, after the forklift arm three 35 finishes picking up the goods and retracts, the V-shaped limiting rod 45 forms a block at the forklift arm three 35. The blocking effect of the V-shaped limiting rod 45 can prevent the turnover box from shifting in the horizontal state of the forklift arm three 35. Especially when transporting the turnover box, it effectively prevents the goods from sliding or falling during the handling process, ensuring the safety of the goods in the turnover box.

[0017] According to the above technical solution, a stacking device 5 is provided at the equipment housing 1. The stacking device 5 includes two Z-shaped rods 51 and a U-shaped push plate 54. The two Z-shaped rods 51 are respectively fixed to the rear bottom of the forklift arm two 34 on both sides. The U-shaped push plate 54 is slidably installed at the bottom of the double-layer rack 2. Sliders 53 are slidably installed on both sides of the rear side of the U-shaped push plate 54. A spring is provided between the slider 53 and the front side of the lower outer wall of the Z-shaped rod 51. A positioning column 52 is fixed to the rear side of the slider 53, and the two positioning columns 52 respectively penetrate through the lower outer walls of the two Z-shaped rods 51. The front side of the U-shaped push plate 54 is on the same horizontal plane as the front side of the equipment double-layer rack 2. When the forklift arm two 34 expands and moves from the forklift arm one 33 each time, through the setting of the above structure, the U-shaped push plate 54 is closely attached to the outer wall of the lower turnover box, so that the forklift mechanism can stably grab the lower turnover box (the turnover box to be taken out) during the picking process, avoiding the inclination or falling of the items caused by the inaccurate docking of the lower turnover box (the turnover box to be taken out) with the lower turnover box.

[0018] According to the above technical solution, the stacking device 5 further includes two second elastic telescopic rods 55 and two L-shaped telescopic column rods 58. The fixed ends of the two second elastic telescopic rods 55 are respectively slidably installed on both sides of the bottom of the U-shaped push plate 54. On the side where the telescopic ends of the two second elastic telescopic rods 55 are away from each other, an L-shaped side blocking column 56 is fixed. On the rear side below the two L-shaped side blocking columns 56, a Z-shaped track groove plate 57 is fixed. A Z-shaped groove is opened at the top of the Z-shaped track groove plate 57. The two L-shaped telescopic column rods 58 are respectively fixed on the outer walls of the lower sides of the two Z-shaped rods 51 away from each other. The end of the L-shaped telescopic column rod 58 away from the Z-shaped rod 51 is slidably installed inside the Z-shaped groove of the Z-shaped track groove plate 57. A distance of fifty centimeters is left between the vertical columns of the two L-shaped side blocking columns 56 and the front side of the double-layer rack 2. The two L-shaped side blocking columns 56 are respectively located on both sides of the U-shaped push plate 54. Through the setting of the above structure, the L-shaped side blocking columns 56 are in contact with the upper turnover box and the side walls of the lower turnover box. The L-shaped side blocking columns 56 can correct the positions of the upper turnover box and the lower turnover box, so that the L-shaped side blocking columns 56 can effectively prevent the forklift mechanism from tilting excessively when placing the turnover box. Especially when placing the upper turnover box, the problem of misalignment between the upper turnover box and the lower turnover box can be avoided, thereby improving the safety of the entire operation process.

[0019] During use, when multiple turnover boxes are stacked on a stack of products and only the middle turnover box needs to be taken, the two-layer conveyor chain assemblies respectively drive the second forklift arms 34 and the third forklift arms 35 of the two layers to expand and move from the first forklift arm 33 until the third forklift arms 35 of the two layers move to the position of the turnover box, and the third forklift arms 35 drive the bearing plate 38 to move to the flange edge of the turnover box. Then, first start the upper electric push rod 39. The telescopic end of the upper electric push rod 39 pushes the top plate 310 to drive the cushion block 312 to move upward. The upper cushion block 312 lifts the upper turnover box. At this time, the upper turnover box is separated from the lower turnover box up and down, and the upper turnover box is no longer stacked on the lower turnover box (the turnover box to be taken out). It should be noted that the displacement distance of the telescopic end of the lower electric push rod 39 here is only half of the displacement distance of the telescopic end of the upper electric push rod 39. Therefore, after the telescopic end of the lower electric push rod 39 extends, it will not drive the lifted lower turnover box (the turnover box to be taken out) to contact the bottom of the upper turnover box. Then, start the lower electric push rod 39. The telescopic end of the lower electric push rod 39 pushes the top plate 310 to drive the cushion block 312 to move upward. The lower cushion block 312 lifts the lower turnover box (the turnover box to be taken out). Then, the lower conveyor chain assembly drives the second forklift arms 34 and the third forklift arms 35 of the lower layer to retract, and the lower turnover box (the turnover box to be taken out) is received into the double-layer rack 2, thus completing the operation of taking the turnover box. In the forklift mechanism of the present invention, the traditional clamping method is changed to lifting the flange edge of the turnover box.

[0020] It should be noted that due to the different models of the turnover boxes, turnover boxes of different sizes are usually placed on the warehouse shelves. Before each use of the forklift mechanism, the distance between the two forklift devices 3 on both sides can be adjusted according to the width of the turnover box. The servo motor 375 is started, and the output end of the servo motor 375 drives the gear ring 374 to rotate. The gear ring 374 drives the gear sleeve 372 to rotate. The gear sleeve 372 drives the lead screw 373 to push the first forklift arm 33 to drive the slide plate 32 to displace inside the U-shaped guide rail 31, so that the first forklift arm 33 moves away from or approaches the center of the double-layer rack 2, so that the distance between the two forklift devices 3 on both sides can be adjusted to adapt to turnover boxes of different models.

[0021] After the second forklift arm 34 and the third forklift arm 35 are unfolded and moved from the first forklift arm 33 each time, when the third forklift arm 35 drives the contact rod 41 to move along with the U-shaped sleeve 42, the contact rod 41 does not abut against the inner wall of the equipment housing 1 at this time. Under the elastic force between the contact rod 41 and the U-shaped sleeve 42, the contact rod 41 pops out from the U-shaped sleeve 42, and the contact rod 41 drives the sliding column 44 to move backward. The sliding column 44 slides along the U-shaped rod 43, and the sliding column 44 pulls the U-shaped rod 43 to drive the V-shaped limiting rod 45 to swing (from the state where the V-shaped limiting rod 45 is at a 90-degree angle to the third forklift arm 35 to the state where the V-shaped limiting rod 45 is horizontal to the third forklift arm 35), so that the V-shaped limiting rod 45 does not form an obstruction at the third forklift arm 35. After the third forklift arm 35 finishes picking up the goods and retracts, the third forklift arm 35 drives the contact rod 41 to abut against the inner wall of the equipment housing 1 again through the U-shaped sleeve 42. The contact rod 41 drives the sliding column 44 to push the U-shaped rod 43 to drive the V-shaped limiting rod 45 to swing (from the state where the V-shaped limiting rod 45 is horizontal to the third forklift arm 35 to the state where the V-shaped limiting rod 45 is at a 90-degree angle to the third forklift arm 35). The V-shaped limiting rod 45 re-forms an obstruction at the third forklift arm 35. The blocking effect of the V-shaped limiting rod 45 can prevent the turnover box from shifting in the horizontal state of the third forklift arm 35. Especially when transporting the turnover box, it effectively prevents the goods from sliding or falling during the handling process, ensuring the safety of the goods in the turnover box.

[0022] Each time the fork arm two 34 moves outwards from the fork arm one 33, the fork arm two 34 drives the U-shaped push plate 54 to move along with it through the Z-shaped rod 51, the slider 53 and the spring corresponding to the slider 53 until the U-shaped push plate 54 abuts against the outer wall of the turnover box below the lower turnover box (the turnover box to be taken out). As the fork arm two 34 drives the Z-shaped rod 51 to continue moving, since the U-shaped push plate 54 has abutted against the outer wall of the lower turnover box, the U-shaped push plate 54 will no longer displace, while the Z-shaped rod 51 moves along the outside of the positioning column 52 and leans towards the U-shaped push plate 54. Under the elastic force of the spring corresponding to the slider 53, the slider 53 can push the U-shaped push plate 54 to closely adhere to the outer wall of the lower turnover box, so that the fork mechanism can stably grasp the lower turnover box (the turnover box to be taken out) during the object-taking process, avoiding the tilting or dropping of items caused by inaccurate docking between the lower turnover box (the turnover box to be taken out) and the turnover box below.

[0023] It should be noted that there is a through-hole for the Z-shaped rod 51 below the double-layer rack 2. When the fork arm one 33 moves away from or towards the center of the double-layer rack 2, the Z-shaped rod 51 will drive the slider 53 to move towards the center of the U-shaped push plate 54 through the positioning column 52, so that the presence of the Z-shaped rod 51, the positioning column 52 and the slider 53 will not interfere with the displacement of the fork arm one 33.

[0024] When the Z-shaped rod 51 moves along the outside of the positioning column 52 and leans towards the U-shaped push plate 54, the Z-shaped rod 51 drives the L-shaped telescopic column rod 58 to move along with it. The L-shaped telescopic column rod 58 slides inside the Z-shaped groove of the Z-shaped track groove plate 57, and the L-shaped telescopic column rod 58 pushes the Z-shaped track groove plate 57 to drive the L-shaped side baffle column 56 to move towards the center of the U-shaped push plate 54. The L-shaped side baffle column 56 drives the elastic telescopic rod two 55 to move towards the center of the U-shaped push plate 54 along the bottom of the U-shaped push plate 54 until the L-shaped side baffle column 56 abuts against the side walls of the upper turnover box and the lower turnover box. After the lower turnover box (the turnover box to be taken out) is received into the double-layer rack 2, the L-shaped side baffle column 56 and the U-shaped push plate 54 are reset to the initial state. Then, the fork mechanism is driven by an external lifting module to move downwards as a whole. At this time, the upper fork device 3 can place the upper turnover box lifted by the bucket on the top of the lower turnover box. The L-shaped side baffle column 56 can correct the positions of the upper turnover box and the lower turnover box, so that the L-shaped side baffle column 56 can effectively prevent the fork mechanism from tilting excessively when placing the turnover box. Especially when placing the upper turnover box, the problem of misalignment between the upper turnover box and the lower turnover box can be avoided, thus improving the safety of the entire operation process.

[0025] It should be noted that the overall downward movement of the fork mechanism is realized by an external lifting module. The external lifting module is an existing device used to control the up and down movement of the fork mechanism, and will not be elaborated here too much.

[0026] It should also be noted that, due to the telescopic structures of the second elastic telescopic rod 55 and the L-shaped telescopic column rod 58, after the L-shaped side blocking column 56 abuts against the side wall of the turnover box below, when the L-shaped side blocking column 56 continues to move, the telescopic ends of the second elastic telescopic rod 55 and the L-shaped telescopic column rod 58 will be stretched, so that the L-shaped side blocking column 56 can adapt to turnover boxes of different models.

[0027] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A variable pitch double-layer fork mechanism, comprising an equipment housing (1), characterized in that: Inside the device housing (1), a double-layer rack (2) is fixedly installed. On both sides of the two layers of the double-layer rack (2), a forklift device (3) is provided. The forklift device (3) includes two U-shaped guide rails (31) fixed to the top of the laminate of the double-layer rack (2), two sliding plates (32) respectively slidably installed inside the two U-shaped guide rails (31). On the side of the two sliding plates (32) close to the center of the double-layer rack (2), a first forklift arm (33), a second forklift arm (34), and a third forklift arm (35) are sequentially arranged. On the outer walls of the first forklift arm (33) and the second forklift arm (34), a number of bearing wheels (36) are evenly and equidistantly rotatably installed. The first forklift arm (33), the second forklift arm (34), and the third forklift arm (35) are driven by a conveyor chain assembly. A driving assembly (37) is arranged outside the first forklift arm (33). On the top surface of the side of the third forklift arm (35) away from the second forklift arm (34), a number of bearing plates (38) are fixed. On the rear side of the side of the third forklift arm (35) away from the second forklift arm (34), an electric push rod (39) is fixed. On the front side of the side of the third forklift arm (35) away from the second forklift arm (34), a first elastic telescopic rod (311) is fixed. Between the telescopic ends of the electric push rod (39) and the first elastic telescopic rod (311), a top plate (310) is fixed. On the top of the top plate (310), a number of cushion blocks (312) are fixed.

2. The variable pitch double-layer fork mechanism according to claim 1, characterized in that: The driving assembly (37) is used to drive the first forklift arm (33) to move horizontally. The driving assembly (37) includes a fixing plate (371), a gear sleeve (372), a lead screw (373), a toothed ring (374), and a servo motor (375). The fixing plate (371) is fixed to the top of the laminate of the double-layer rack (2). The servo motor (375) is fixed to the outer wall above the fixing plate (371). The toothed ring (374) is fixed to the outer wall of the output end of the servo motor (375). The lead screw (373) is fixed to the outer wall of the first forklift arm (33). A circular hole for the lead screw (373) to pass through is opened on the lower outer wall of the fixing plate (371). The gear sleeve (372) is rotatably installed on the outer wall of the fixing plate (371), and the inside of the gear sleeve (372) is threadedly connected to the outside of the lead screw (373).

3. The variable pitch double-layer fork mechanism according to claim 1, characterized in that: The corresponding number of bearing wheels (36) of the first forklift arm (33) are used to guide and support the second forklift arm (34). The corresponding number of bearing wheels (36) of the second forklift arm (34) are used to guide and support the third forklift arm (35).

4. A variable pitch double-layer fork mechanism according to claim 1, characterized in that: The cushion blocks (312) penetrate through the bottom of the bearing plates (38), and the tops of the cushion blocks (312) are on the same horizontal plane as the tops of the bearing plates (38).

5. The variable pitch double-layer fork mechanism according to claim 1, characterized in that: A limiting device (4) is provided at the forklift arm three (35). The limiting device (4) includes a U-shaped sleeve (42), a shaft block (46), and a V-shaped limiting rod (45). The shaft block (46) is fixed to the front side of the forklift arm three (35). The middle of the V-shaped limiting rod (45) is hinged to the bottom of the shaft block (46). A U-shaped rod (43) is fixed to the bottom of the side of the V-shaped limiting rod (45) close to the forklift arm two (34). The U-shaped sleeve (42) is fixed to the side of the forklift arm three (35) close to the forklift arm two (34). A contact rod (41) is slidably installed inside the U-shaped sleeve (42). A spring is provided between the rear side of the contact rod (41) and the outer wall of the U-shaped sleeve (42). A sliding column (44) is fixed to the bottom of the front side of the contact rod (41). The sliding column (44) is slidably installed inside the U-shaped rod (43).

6. The variable pitch double-layer fork mechanism according to claim 5, characterized in that: The rear side of the contact rod (41) abuts against the inner wall of the equipment housing (1).

7. The variable pitch double-layer fork mechanism according to claim 1, characterized in that: A stacking device (5) is provided at the equipment housing (1). The stacking device (5) includes two Z-shaped rods (51) and a U-shaped push plate (54). The two Z-shaped rods (51) are respectively fixed to the bottom rear sides of the forklift arms two (34) on both sides. The U-shaped push plate (54) is slidably installed at the bottom of the double-layer rack (2). Sliders (53) are slidably installed on both rear sides of the U-shaped push plate (54). A spring is provided between the slider (53) and the front side of the outer wall below the Z-shaped rod (51). A positioning column (52) is fixed to the rear side of the slider (53), and the two positioning columns (52) respectively penetrate through the outer walls below the two Z-shaped rods (51).

8. The variable pitch double-layer fork mechanism according to claim 7, characterized in that: The front side of the U-shaped push plate (54) is on the same horizontal plane as the front side of the equipment double-layer rack (2).

9. The variable pitch double-layer fork mechanism according to claim 7, wherein: The stacking device (5) further includes two elastic telescopic rods two (55) and two L-shaped telescopic column rods (58). The fixed ends of the two elastic telescopic rods two (55) are respectively slidably installed on both sides of the bottom of the U-shaped push plate (54). L-shaped side blocking columns (56) are fixed to the sides of the telescopic ends of the two elastic telescopic rods two (55) away from each other. Z-shaped track groove plates (57) are fixed to the rear sides below the two L-shaped side blocking columns (56). A Z-shaped groove is provided at the top of the Z-shaped track groove plate (57). The two L-shaped telescopic column rods (58) are respectively fixed to the sides of the outer walls below the two Z-shaped rods (51) away from each other. The end of the L-shaped telescopic column rod (58) away from the Z-shaped rod (51) is slidably installed inside the Z-shaped groove of the Z-shaped track groove plate (57).

10. The variable pitch double-layer fork mechanism according to claim 9, wherein: A spacing of fifty centimeters is left between the vertical columns of the two L-shaped side blocking columns (56) and the front side of the double-layer rack (2). The two L-shaped side blocking columns (56) are respectively located on both sides of the U-shaped push plate (54).

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