Pallet fork distance adjusting device

Abstract

The invention belongs to the technical field of carrying machinery, and particularly relates to a fork distance adjusting device. A pallet fork distance adjusting device comprises a side shifter, a pallet fork frame connecting piece, two pallet fork mounting plates and two driving assemblies. The side shifter comprises a frame and an oil cylinder, the oil cylinder is installed on the frame, and the two ends of the fork arm carrier connecting piece are connected with the oil cylinder and the forklift respectively. The two pallet fork mounting plates are mounted on the frame in a sliding manner; and each pallet fork mounting plate is connected with a pallet fork. The driving assemblies are mounted in the frame, and the two driving assemblies are connected with the two pallet fork mounting plates correspondingly. The driving assembly comprises a motor, a lead screw, a fixing plate and a nut, and the nut is connected with the pallet fork mounting plate. The adjusting mode of the motor and the lead screw is adopted, multiple oil pipelines do not need to be arranged in the pallet fork distance adjusting device, the structure of the pallet fork distance adjusting device is simplified, meanwhile, the lead screw is adopted, the moving stroke of the pallet fork mounting plate can be increased in the limited space of the frame, the pallet fork distance adjusting device can be suitable for different scenes, and the practicability of the pallet fork distance adjusting device is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of handling machinery, and in particular relates to a fork distance adjusting device. Background Art

[0002] With the rapid development of the logistics industry, all walks of life are looking for effective ways to improve handling efficiency and increase storage capacity. Among them, forklifts, as an important tool in the production and transportation process, can easily carry large, regular-shaped heavy objects or pallets, which not only improves handling efficiency, but also greatly reduces the labor burden of workers. For some places with narrow passages and high space utilization requirements (such as large containers, aircraft cargo holds, etc.), in order to increase the storage capacity, it is necessary to stack the goods as close to the wall of the box as possible. At this time, a side shifter is needed to drive the two forks to move left and right relative to the vehicle body as a whole, so as to achieve fork picking of goods in such places. If the forked goods are irregular in space, it is necessary to adjust the position of each fork separately, and sometimes even need to adjust both forks to the end face of the vehicle body so that the forks are as close to the position of the cargo hold as possible. In this way, it is necessary to add a single fork distance adjustment structure on the basis of the traditional side shifter.

[0003] The existing single-fork distance adjustment structure can only adjust the displacement of a single fork during the adjustment process. And because its power source is a hydraulic cylinder, it is limited by the difficulty and cost of manufacturing a multi-position valve body and the limitation of the space size occupied by the valve body itself, making the types of traditional forklifts with side shifters and single-fork distance adjustment functions very few. If the existing rod cylinder is used to realize the separate movement of two forks, 4 oil pipes need to be added, thereby increasing the complexity of the hydraulic pipeline in the entire distance adjustment structure under the limited size of the fork frame, and increasing the processing difficulty and manufacturing cost of the entire fork distance adjustment device. Moreover, due to the complex structure of the hydraulic cylinder and the size of the cylinder body, the range of movement of the fork adjusted by the single-fork distance adjustment structure is very narrow, generally not exceeding half the length of the side shifter slide rail, and it is impossible to achieve the movement of a single fork on the full track. This results in the fork adjusted by the existing single-fork distance adjustment structure being unable to meet the requirements of forking goods with special bottom space or very close to the warehouse wall as a whole, making its practicality poor. Summary of the invention

[0004] In order to solve the problem in the prior art that the adjustment range of a single-fork distance-adjustable fork is very narrow and the positions of two forks cannot be adjusted arbitrarily, the present invention provides a fork distance-adjusting device.

[0005] The present invention is implemented by the following technical scheme: a fork distance adjustment device, which includes a side shifter, a fork frame connecting piece, two fork mounting plates and two driving assemblies; the side shifter includes a frame and a cylinder, and the cylinder is installed on the frame; one end of the fork frame connecting piece is fixedly connected to the cylinder, and the other end of the fork frame connecting piece is connected to the body mast of the forklift; the fork frame connecting piece is driven by the cylinder to reciprocate on the frame, so that the fork frame connecting piece and the frame can move relative to each other; the two fork mounting plates are arranged along the length direction of the frame and slidably installed on the frame; each fork mounting plate is used to connect the forks, and the two forks are driven by the two fork mounting plates to move on the frame to adjust the positions of the two forks; the two driving assemblies are installed on the frame The frame is provided with two driving assemblies which are centrally symmetrical about the intersection of the diagonals of the frame; the driving assembly comprises a motor, a screw rod, a fixing plate and a nut, one end of the fixing plate is fixedly mounted on the frame, the screw rod is arranged along the length direction of the frame, one end of the screw rod is rotatably mounted on one end of the frame, and the other end of the screw rod is placed along the length direction of the frame and connected to the fixing plate through a bearing; the motor is fixedly mounted on the fixing plate and connected to the screw rod, and the nut is mounted on the screw rod; the nuts on the two driving assemblies are respectively fixedly connected to the two fork mounting plates; the screw rod is driven to rotate by the motor, and the screw rod drives the nut to move along the axial direction of the screw rod, so as to realize driving the fork mounting plate to move along the length direction of the frame.

[0006] As a further improvement of the present invention, an absolute encoder is installed on the motor, and the absolute encoder is used to provide real-time feedback of the position of the fork mounting plate on the screw rod.

[0007] As a further improvement of the present invention, the motor and the screw rod are installed side by side on the fixing plate along the width direction of the frame, and the motor and the screw rod are connected by a chain.

[0008] As a further improvement of the present invention, a support core shaft is provided between the screw rod and the frame, one end of the support core shaft is mounted on the frame, and the other end of the support core shaft is connected to the screw rod via bearing 2.

[0009] As a further improvement of the present invention, the second bearing is a deep groove ball bearing.

[0010] As a further improvement of the present invention, a pair of slide grooves 1 are provided on the frame, and the pair of slide grooves 1 are symmetrically arranged in the length direction of the frame. Both ends of the fork mounting plate are respectively inserted into the slide grooves 1, so that the fork mounting plate can slide along the slide grooves 1 in the length direction of the frame.

[0011] As a further improvement of the present invention, the oil cylinder is a double-rod hydraulic cylinder, which includes a rod body and a cylinder body, the two ends of the rod body are respectively fixed on the frame, the cylinder body is sleeved on the outside of the rod body, the cylinder body is fixedly connected to the fork frame connecting piece, and the fork frame connecting piece is driven to move by the cylinder body moving along the axial direction of the rod body.

[0012] As a further improvement of the present invention, the fork mounting plate includes a mounting plate body and a connecting plate, the mounting plate body is slidably installed in the frame along the length direction of the frame, the connecting plate includes a plate body one, a plate body two and a limiting ring, the plate body one is fixedly installed on the mounting plate body, the plate body two is fixedly installed on the plate body one, the limiting ring is sleeved on the nut, the plate body two is provided with a through hole, the nut is inserted into the plate body two through the through hole, the nut is provided with a plurality of screw holes one, the plate body two is provided with a plurality of screw holes two, the limiting ring is provided with a plurality of screw holes three, one end of the screw hole two is aligned with the screw hole one, and the other end of the screw hole two is aligned with the screw hole three; the screw passes through the screw hole one, the screw hole two and the screw hole three in sequence to fix the nut and the plate body two.

[0013] As a further improvement of the present invention, the aperture of the through hole is larger than the outer diameter of the nut; the inner diameter of the limiting ring is larger than the outer diameter of the nut and smaller than the aperture of the through hole.

[0014] As a further improvement of the present invention, a slider is provided on the cylinder body, a second slide groove is provided on the frame, the second slide groove is arranged along the length direction of the frame, the second slide groove is parallel to the first slide groove, and the slider is slidably installed in the second slide groove.

[0015] The technical solution provided by the present invention has the following beneficial effects:

[0016] (1) The fork distance adjustment device of the present invention is provided with two drive components, each of which controls a single fork mounting plate, so that the adjustment of the two forks is independent of each other. In the actual adjustment process, the two forks can be adjusted to move to the left side of the frame or to the right side of the frame by the two drive components, and the distance between the two forks can also be adjusted. Compared with the prior art in which the two forks can only move synchronously and the moving distance is very short by adjusting the oil cylinder, the forks are adjusted by adjusting the motor and the screw rod of the present invention, so that the moving range of the forks is larger and can be applied to more usage scenarios.

[0017] (2) The fork distance adjustment device of the present invention adopts the adjustment method of the motor and the screw rod, and does not need to set multiple oil pipes in the fork distance adjustment device, which can effectively avoid the disadvantage of complex structure caused by multiple oil pipes when the oil cylinder is driven. The drive assembly of the present invention has a simple structure, and the use of the screw rod can increase the moving stroke of the fork mounting plate within the limited space of the frame, thereby improving the practicality of the entire fork distance adjustment device.

[0018] (3) The motor and the lead screw in the fork distance adjustment device of the present invention are connected by a chain instead of a coupling, thereby further increasing the length of the lead screw within the limited range of the frame, thereby increasing the moving stroke of the fork, so that the fork distance adjustment device of the present invention can fork goods in more scenarios.

[0019] (4) The present invention sets an absolute value encoder on the motor, which can provide real-time feedback on the position of the fork mounting plate on the screw rod. The position of the fork can be determined by the position of the fork mounting plate. Therefore, in actual operation, the absolute value encoder can be set to improve the accuracy of the fork when it is inserted into the cargo fork picking point when picking up cargo. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A three-dimensional diagram of the fork distance adjusting device provided by the present invention.

[0021] Figure 2 This is a front view of the fork distance adjusting device provided by the present invention.

[0022] Figure 3 For the present invention Figure 2 Enlarged view of the cross section along AA.

[0023] Figure 4 It is a partial structural schematic diagram of the driving assembly when it is installed on the frame in the present invention.

[0024] Figure 5 It is a partial structural schematic diagram of another angle when the driving assembly in the present invention is installed on the frame.

[0025] Figure 6 For the present invention Figure 4 main view.

[0026] Figure 7 For the present invention Figure 6 A partial enlarged schematic diagram of the cross section along BB in the middle.

[0027] Markings in the figure are: 111, short rod; 112, long rod; 113, slide 1; 114, slide 2; 12, cylinder; 121, cylinder body; 122, rod body; 123, slider; 2, fork frame connecting piece; 31, mounting plate body; 321, plate body 1; 322, plate body 2; 323, limit ring; 324, through hole; 41, motor; 42, screw rod; 43, fixing plate; 44, nut; 45, support spindle; 46, bearing 2. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0029] In the description of the present invention, it should be noted that for directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating directions and positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific protection scope of the present invention. The terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. The terms "including" and "having" in the specification and claims of the present invention and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device including a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] This embodiment provides a fork distance adjustment device, please refer to Figure 1 and Figure 2, which includes a side shifter, a fork frame connector 2, two fork mounting plates and two drive components. The side shifter includes a frame and a cylinder 12, and the cylinder 12, the two fork mounting plates and the two drive components are all installed on the frame. One end of the fork frame connector 2 is fixedly connected to the cylinder 12, and the other end of the fork frame connector 2 is connected to the body gantry of the forklift. The fork frame connector 2 is driven by the cylinder 12 to reciprocate on the frame, so that the fork frame connector 2 and the frame can move relative to each other. In the actual adjustment process, the fork frame connector 2 is first fixedly connected to the body gantry of the forklift. Then, according to the position of the forked cargo, the frame is driven by the cylinder 12 to move relative to the fork frame connector 2. In the actual operation process, because the fork frame connector 2 is fixedly connected to the body gantry of the forklift, the position of the frame is adjusted by the drive of the cylinder 12. For example, when there is an obstacle on the left side of the goods to be forked, the oil cylinder 12 can be used to drive the frame to move rightward relative to the fork frame connector 2, so that the frame can move rightward as a whole, thereby avoiding the obstacle on the left side of the goods to be forked. Or after the forked goods are dumped to the designated location, the goods need to be placed closer to the wall. At this time, the forklift itself is not easy to move. The oil cylinder 12 can be used to drive the frame to move, so that the frame drives the goods to move to a position close to the wall through the fork mounting plate and the fork. By setting a side shifter, the forklift can be used in these scenarios, thereby improving the practicality of the entire fork distance adjustment device.

[0031] Please refer to Figure 1 and Figure 2 , the frame may include two short rods 111 and two long rods 112, and the rectangular structure of the frame may be formed by the two short rods 111 and the two long rods 112. The oil cylinder 12 is a double-rod hydraulic cylinder, which includes a rod body 122 and a cylinder body 121. The two ends of the rod body 122 are respectively fixed on the two short rods 111, the cylinder body 121 is sleeved on the outside of the rod body 122, and the rod body 122 is solidly connected to the fork frame connecting member 2. The cylinder body 121 moves back and forth along the axis direction of the rod body 122 to drive the fork frame connecting member 2 to move relative to the frame. In this embodiment, since the fork distance adjustment device is fixedly connected between the fork frame connecting member 2 and the body mast of the forklift during the installation process, under the drive of the oil cylinder 12, the frame is actually moved relative to the fork frame connecting member 2. Through this setting, the frame as a whole can move relative to the forklift, thereby driving the fork mounting plate installed on the frame to move, thereby adapting to the fork picking operation of goods in different positions.

[0032] Please refer to Figure 3The frame is provided with a pair of slide grooves 113 and a pair of slide grooves 114. The pair of slide grooves 113 are symmetrically arranged on the two long rods 112 of the frame along the length direction of the long rod 112, and the pair of slide grooves 114 are also symmetrically arranged on the two long rods 112 of the frame along the length direction of the long rod 112. The slide groove 113 on the same long rod 112 is located below the slide groove 114. A slider 123 is fixed on the side of the cylinder body 121 close to the slide groove 113, and the slider 123 is slidably installed in the slide groove 114. By providing the slider 123 and the slide groove 114, the stability of the cylinder body 121 when moving along the axial direction of the rod body 122 can be improved.

[0033] In this embodiment, there are two fork frame connectors 2, and both fork frame connectors 2 are arranged in parallel along the width direction of the frame. Among them, the side of each fork frame connector 2 close to the oil cylinder 12 is fixed to the cylinder body 121 by screw connection, and the other end of the fork frame connector 2 is slidably installed on the long rod 112 away from the cylinder body 121. A guide block is also provided on the side where the fork frame connector is connected to the long rod 112, and the guide block is inserted into the second slide groove 114. By providing the guide block, the stability of the fork frame connector 2 when relative movement occurs with the frame can be further improved.

[0034] The fork frame connecting member 2 may also be provided with a mounting hole three, and the mounting hole three is used to connect with the body mast of the forklift.

[0035] The two fork mounting plates are arranged in parallel along the length direction of the long rod 112, and the two ends of each fork mounting plate are slidably mounted on the slide slot 113, so that the fork mounting plate can move along the length direction of the long rod 112. Each fork mounting plate is used to connect the forks, and the two forks are driven to move on the frame by the two fork mounting plates to adjust the positions of the two forks.

[0036] Please refer to Figure 4 and Figure 5 The two drive assemblies are mounted on the frame, and the two drive assemblies are centrally symmetrical about the intersection of the diagonal lines of the frame. The central symmetry can reasonably distribute the structure of the two drive assemblies within the limited space of the existing frame, making the overall structure compact, and the two drive assemblies can each drive the fork mounting plate to move along the axial direction of the screw rod 42, while increasing the range of movement of the two forks without additionally increasing the size of the frame.

[0037] Please refer to Figure 4 and Figure 5The drive assembly includes a motor 41, a screw rod 42, a fixed plate 43 and a nut 44. The screw rod 42 is arranged along the length direction of the frame. For ease of understanding, the two short rods 111 are respectively referred to as short rod 111-1 and short rod 111-2. The fixed plate 43 is fixed on one of the long rods 112 and is close to the short rod 111-1. One end of the screw rod 42 is rotatably mounted on the short rod 111-2, and the other end of the screw rod 42 is connected to the fixed plate 43 through a bearing 1. The motor 41 is fixed to the fixed plate 43 and connected to the screw rod 42. The nut 44 is mounted on the screw rod 42. The nuts 44 on the two drive assemblies are respectively fixedly connected to the two fork mounting plates. The motor 41 drives the screw rod 42 to rotate, and the screw rod 42 drives the nut 44 to move along the axial direction of the screw rod 42, so as to drive the fork mounting plate to move along the length direction of the frame. In this embodiment, by setting the motor 41 and the screw rod 42, there is no need to set multiple oil pipes, which can effectively avoid the disadvantages of the oil cylinder 12 drive, making the structure of the entire fork distance adjustment device simpler, and at the same time can increase the travel of the fork in the frame to meet the fork to effectively fork the goods in different positions. In addition, in this embodiment, by setting two drive components, the two drive components are respectively connected to the two fork mounting plates, so that each drive component can control a single fork mounting plate separately, and the fork mounting plate is connected to the fork. Therefore, the adjustment of the two forks in this embodiment is independent of each other, so that the two forks move to the left side of the frame, or move to the right side of the frame. In addition, the spacing between the two forks can be adjusted at will. Compared with the prior art, the two forks can only move synchronously and the moving distance is very short through the adjustment method of the oil cylinder 12. The adjustment method of this embodiment makes the adjustment of the two forks more free and without limitations, so that it can be applied to more usage scenarios. Furthermore, by providing a screw rod 42, one end of the screw rod 42 is rotatably connected to the short rod 111 of the frame, and the other end of the screw rod 42 is connected to the fixing plate 43 through a bearing. By selecting the screw rod 42, the moving stroke of the fork mounting plate can be increased within a limited space, that is, the movable range of the fork in the frame can be increased to the maximum extent, thereby improving the practicality of the entire fork distance adjustment device.

[0038] It is understandable that the bearing 1 can be a derivative of a conventional double-row angular contact bearing, which has its own outer ring bearing seat, making its external dimensions small and suitable for such places with a relatively compact structure. The bearing can withstand radial force and axial force, and in this embodiment, the connection between the screw rod and the fixed plate will be subject to the friction force of the axial fork movement and the radial tension of the chain. By installing a bearing 1 at the connection between the screw rod and the fixed plate, it is possible to simultaneously withstand the friction force of the axial fork movement and the radial tension of the chain, so that there is no need to use two bearings to withstand the forces in these two directions respectively, thereby simplifying the structure of the entire device.

[0039] Furthermore, the motor 41 and the lead screw 42 are arranged side by side along the length direction of the short rod 111. The side by side arrangement can further increase the limit stroke of the lead screw 42, thereby increasing the movement stroke of the fork mounting plate, so that the two forks connected to the fork mounting plate can be moved freely along the axial direction of the lead screw 42, so as to adjust the positions of the two forks according to the actual positions of the goods to be forked, thereby realizing the forking operation of goods in different positions or conditions, and improving the practicality of the entire device.

[0040] The screw rod 42 can be a screw rod 42 with a small lead. In the present embodiment, the torque of the motor is relatively large. By selecting a screw rod 42 with a small lead, it can provide a relatively large axial thrust while also allowing the nut 44 to move very slowly along the axial direction of the screw rod 42, so that it can also be used as a reducer. Therefore, there is no need to set a reducer in the present embodiment, thereby saving space and manufacturing costs.

[0041] Please refer to Figure 6 In this embodiment, the motor 41 may be a servo motor 41. The motor 41 and the screw rod 42 may be connected by a chain. The chain transmission method can increase the length of the screw rod 42 as much as possible while eliminating the coupling. The increase in the length of the screw rod 42 means that the range of motion of the fork is increased, so that the fork can adjust its position according to the goods in different positions, so that the forklift can use the fork to fork goods in more working conditions, thereby improving the practicality of the forklift.

[0042] It is understandable that the motor 41 may also be provided with an absolute encoder, which can provide real-time feedback on the position of the fork mounting plate on the screw rod 42, and the position of the fork can be determined by the position of the fork mounting plate. Therefore, in the actual operation process, the fork can be accurately moved to the specified position according to the demand through the cooperation of the absolute encoder, the motor 41 and the control system. The absolute encoder is encoded by mechanical position determination, it does not need to be memorized, does not need to find a reference point, and does not need to count all the time. When the position needs to be known, its position is read. Therefore, the use of an absolute encoder can accurately know the real-time position of the fork and improve the accuracy of the fork adjustment process. Specifically, in the present embodiment, the absolute encoder can accurately feedback to the control system how many times the motor 41 has rotated, and when the motor 41 rotates different numbers of times, the corresponding position of the fork mounting plate is also different, so the absolute encoder can be used to understand the real-time position of the fork mounting plate, that is, to understand the position of the fork. When actually picking up goods, the fork can be accurately moved to the specified position to pick up the goods through the cooperation of the control system, the motor 41 and the absolute encoder, thereby improving the accuracy of the fork in picking up the goods. In the prior art, even if the absolute encoder is installed on the oil cylinder 12, the start and stop positions of the oil cylinder 12 will have a certain delay in feedback, which will cause the position of the fork mounting plate read by the absolute encoder to be inaccurate, resulting in a deviation between the actual position of the fork and the position that needs to be adjusted, thereby reducing the accuracy of the fork in picking up the goods.

[0043] Furthermore, the fork distance adjusting device in this embodiment can be installed on an unmanned forklift, and then the unmanned forklift itself and the fork distance adjusting device can be controlled by a control system to achieve fully automatic forking operation of the goods.

[0044] Please refer to Figures 5 to 7 A support mandrel 45 is provided between the screw rod 42 and the short rod 111, one end of the support mandrel 45 is mounted on the short rod 111, and the other end of the support mandrel 45 is connected to the screw rod 42 through a bearing 2 46. In this embodiment, a mounting hole 1 is provided on the short rod 111, and the support mandrel 45 is inserted into the mounting hole 1 and fixed to the short rod 111 through a fixing plate. The axial movement and rotation of the support mandrel 45 itself can be restricted by providing a fixing plate. It can be understood that, in this embodiment, compared with the processing method of directly installing the bearing on the frame, the present application can simplify the processing requirements of the frame and reduce the production and manufacturing cost of the entire fork distance adjustment device by providing the support mandrel 45.

[0045] The bearing 2 46 can be a deep groove ball bearing, which can limit the movement of the screw 42 in the radial direction, but the screw 42 can still move in a small range in the axial direction. By selecting a deep groove ball bearing, the stability of the screw 42 can be ensured while preventing the screw 42 from stress concentration when it is deformed by axial force, thereby extending the service life of the screw 42. The deep groove ball bearing makes the connection between the screw 42 and the support mandrel 45 a floating connection, which can absorb the error between the screw 42 and the support mandrel 45 during the manufacturing process, thereby reducing the assembly accuracy between the support mandrel 45 and the screw 42.

[0046] It is understandable that when the screw rod 42 is vertically arranged during use, the end thereof away from the motor 41 may not be fixed. When the screw rod 42 is horizontally arranged during use and the length of the screw rod 42 is long, the deep groove ball bearing and the support mandrel 45 are required to limit the radial movement of the screw rod to improve the stability of the movement of the screw rod 42.

[0047] Furthermore, in this embodiment, by providing a support mandrel 45 to limit and fix the end of the screw rod 42 away from the motor 41, the deflection of the end of the screw rod 42 away from the motor 41 due to its own weight can be reduced. The deflection here refers to the displacement difference between the actual position of the end of the screw rod 42 away from the motor 41 and the ideal position when the screw rod 42 rotates. By reducing the displacement difference, the screw rod 42 can be prevented from colliding with other parts when rotating, thereby improving the stability of the screw rod 42 when rotating.

[0048] Please refer to Figures 5 to 7The fork mounting plate includes a mounting plate body 31 and a connecting plate. The two ends of the mounting plate body 31 are respectively inserted into the slide grooves 113 of the two long rods 112, so that the mounting plate body 31 can move along the two slide grooves 113 in the length direction of the long rods 112. The mounting plate body 31 is also provided with a plurality of mounting holes 2, and the fork is fixed to the mounting plate body 31 through the plurality of mounting holes. The connecting plate includes a plate body 1 321, a plate body 2 322 and a limiting ring 323. The plate body 1 321 is fixedly mounted on the mounting plate body 31, and the plate body 2 322 is fixedly mounted on the plate body 1 321, and the position where the plate body 2 322 is mounted on the plate body 1 321 is aligned with the screw rod 42. The plate body 2 322 is provided with a through hole 324, and the nut 44 is inserted into the plate body 2 322 through the through hole 324, and the limiting ring 323 is sleeved on the nut 44. Nut 44 is provided with multiple screw holes 1, plate body 2 322 is provided with multiple screw holes 2, and stop ring 323 is provided with multiple screw holes 3. Along the axial direction of screw rod 42, one end of screw hole 2 is aligned with screw hole 1, and the other end of screw hole 2 is aligned with screw hole 3. Screws are passed through screw hole 1, screw hole 2 and screw hole 3 in sequence to fix nut 44 and plate body 2 322. Nut 44 is fixed to plate body 2 322 and both sides of mounting plate body 31 are slidably mounted in slide groove 1 113, so that when motor 41 drives screw rod 42 to rotate through chain, nut 44 drives mounting plate body 31 to slide along slide groove 1 113 through connecting plate, thereby adjusting the position of fork on screw rod 42.

[0049] Please refer to Figures 5 to 7 In this embodiment, the aperture of the through hole 324 is slightly larger than the outer diameter of the nut 44, and the screw between the fixing nut 44 and the plate body 322 is a hexagon socket head shoulder screw with dimensional accuracy. By selecting this screw and combining the aperture of the through hole 324 that is slightly larger than the outer diameter of the nut 44, when the screw is fixing the nut 44 and the plate body 322, the nut 44 can still move axially in the through hole 324, and the amplitude of this movement is very small, which will not affect the normal rotation of the screw 42. However, this small range of movement can effectively eliminate the radial force on the mounting plate body 31 when the screw 42 drives the mounting plate body 31 to move along the slide groove 1 113 due to the processing error between the mounting plate body 31 and the slide groove 1 113.

[0050] The inner diameter of the limiting ring 323 is larger than the outer diameter of the nut 44 and smaller than the aperture of the through hole 324. By limiting the inner diameter of the limiting ring 323 as above, the nut 44 can be inserted into the limiting ring 323, and the screw can also fix the nut 44 and the second plate 322 by passing through the screw hole 1, the screw hole 2 and the screw hole 3 in sequence, thereby eliminating the stress that the nut 44 may be subjected to when moving along the axial direction of the screw rod 42 and improving the stability of the nut 44 moving along the axial direction of the screw rod 42.

[0051] The above describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention to be protected. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A fork distance adjustment device, characterized in that: It includes: A side shifter comprising a frame and a cylinder (12), wherein the cylinder (12) is mounted on the frame; A fork frame connecting member (2), one end of the fork frame connecting member (2) is fixedly connected to the oil cylinder (12), and the other end of the fork frame connecting member (2) is connected to the body mast of the forklift; the oil cylinder (12) drives the fork frame connecting member (2) to reciprocate on the frame, so that the fork frame connecting member (2) and the frame can move relative to each other; Two fork mounting plates, both of which are arranged along the length direction of the frame and slidably mounted on the frame; each fork mounting plate is used to connect a fork, and the two forks are driven to move on the frame by the two fork mounting plates to adjust the positions of the two forks; Two drive assemblies, both drive assemblies are mounted on the frame, and the two drive assemblies are centrally symmetrical about the intersection of the diagonals of the frame; the drive assembly comprises a motor (41), a screw rod (42), a fixing plate (43) and a nut (44), one end of the fixing plate (43) is fixedly mounted on the frame, the screw rod (42) is arranged along the length direction of the frame, one end of the screw rod (42) is rotatably mounted on one end of the frame, and the other end of the screw rod (42) is connected to the fixing plate (43) through a bearing. 43); the motor (41) is fixedly mounted on the fixing plate (43) and connected to the screw rod (42), and the nut (44) is mounted on the screw rod (42); the nuts (44) on the two driving assemblies are respectively fixedly connected to the two fork mounting plates; the screw rod (42) is driven to rotate by the motor (41), and the screw rod (42) drives the nut (44) to move along the axial direction of the screw rod (42), so as to drive the fork mounting plate to move along the length direction of the frame.

2. The fork distance adjustment device according to claim 1, characterized in that: An absolute value encoder is installed on the motor (41), and the absolute value encoder is used to provide real-time feedback of the position of the fork mounting plate on the screw rod (42).

3. The fork distance adjustment device according to claim 1, characterized in that: The motor (41) and the screw rod (42) are installed side by side on the fixing plate (43) along the width direction of the frame, and the motor (41) and the screw rod (42) are connected by a chain.

4. The fork distance adjustment device according to claim 1, characterized in that: A support core shaft (45) is provided between the screw rod (42) and the frame. One end of the support core shaft (45) is mounted on the frame, and the other end of the support core shaft (45) is connected to the screw rod (42) via a second bearing (46).

5. The fork distance adjustment device according to claim 1, characterized in that: The second bearing (46) is a deep groove ball bearing.

6. The fork distance adjustment device according to claim 1, characterized in that: The frame is provided with a pair of slide grooves (113), which are symmetrically arranged in the length direction of the frame. The two ends of the fork mounting plate are respectively inserted into the slide grooves (113), so that the fork mounting plate can slide along the slide grooves (113) in the length direction of the frame.

7. The fork distance adjustment device according to claim 6, characterized in that: The oil cylinder (12) is a double-rod hydraulic cylinder, comprising a rod body (122) and a cylinder body (121); both ends of the rod body (122) are respectively fixed on the frame; the cylinder body (121) is sleeved on the outside of the rod body (122); the cylinder body (121) is fixedly connected to the fork frame connecting member (2); and the cylinder body (121) moves along the axial direction of the rod body (122) to drive the fork frame connecting member (2) to move.

8. The fork distance adjustment device according to claim 1, characterized in that: The fork mounting plate comprises a mounting plate body (31) and a connecting plate. The mounting plate body (31) is slidably mounted in the frame along the length direction of the frame. The connecting plate comprises a plate body 1 (321), a plate body 2 (322) and a limiting ring (323). The plate body 1 (321) is fixedly mounted on the mounting plate body (31). The plate body 2 (322) is fixedly mounted on the plate body 1 (321). The limiting ring (323) is sleeved on the nut (44). The plate body 2 (322) is provided with a through hole ( 324), the nut (44) is inserted into the plate body 2 (322) through the through hole (324), the nut (44) is provided with a plurality of screw holes 1, the plate body 2 (322) is provided with a plurality of screw holes 2, the limiting ring (323) is provided with a plurality of screw holes 3, one end of the screw hole 2 is aligned with the screw hole 1, and the other end of the screw hole 2 is aligned with the screw hole 3; the screws pass through the screw hole 1, the screw hole 2 and the screw hole 3 in sequence to fix the nut (44) and the plate body 2 (322).

9. The fork distance adjustment device according to claim 8, characterized in that: The aperture of the through hole (324) is larger than the outer diameter of the nut (44); the inner diameter of the limiting ring (323) is larger than the outer diameter of the nut (44) and smaller than the aperture of the through hole (324).

10. The fork distance adjustment device according to claim 7, characterized in that: The cylinder body (121) is provided with a slider (123), the frame is provided with a second slide groove (114), the second slide groove (114) is arranged along the length direction of the frame, the second slide groove (114) is parallel to the first slide groove (113), and the slider (123) is slidably installed in the second slide groove (114).

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