Forklift counterweight structure

Abstract

The present invention discloses a counterweight structure for a forklift, which includes a counterweight chute opened at the rear end of the forklift. A counterweight mechanism is provided in the counterweight chute. The counterweight mechanism includes a counterweight block slidably connected to the counterweight chute and a moving component for pushing the counterweight block to slide back and forth. An adjustment cavity is formed in the counterweight block, and an adjustment component is provided in the adjustment cavity. The adjustment component includes an adjustment slider slidably connected to the inner wall of the adjustment cavity and a transmission component for driving the adjustment slider to slide. A balance detection mechanism is provided at the bottom of the forklift. The balance detection mechanism includes two measurement components respectively used for detecting the heights of the front side and the rear side of the forklift from the ground and a comparison component for detecting the difference between the measurement values of the two measurement components. The comparison component is electrically connected to a PLC, and the PLC is electrically connected to the moving component and the transmission component. The present invention can well balance gravity and prevent the forklift from tipping forward and backward.

Description

Technical Field

[0001] The present invention relates to the technical field of forklifts, and specifically to a counterweight structure of a forklift. Background Art

[0002] A forklift is an industrial handling vehicle, referring to various wheeled handling vehicles for loading, unloading, stacking, and short-distance transportation of palletized goods. Since a forklift transports goods through a fork frame at the front side, when the goods are heavy, the forklift may tip forward. To solve this problem, a counterweight block is provided at the rear end of the forklift, so that the forklift can maintain balance when stacking goods. Currently, the counterweight blocks at the rear ends of most forklifts put into use in factories are fixedly connected to the forklifts. For example, in a forklift counterweight structure with the application number CN201721814371.9, a formed enclosure is welded to the counterweight frame assembly, and the position of the counterweight block cannot be adjusted to increase the load of the forklift, and it is extremely easy for the forklift to tip forward when transporting heavy goods. Summary of the Invention

[0003] In order to solve at least one technical problem mentioned in the background art, the purpose of the present invention is to provide a forklift counterweight structure to balance gravity and prevent the forklift from tipping forward.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] A forklift counterweight structure includes a counterweight chute opened at the rear end of the forklift. A counterweight mechanism is provided in the counterweight chute. The counterweight mechanism includes a counterweight block slidably connected to the counterweight chute and a moving component for pushing the counterweight block to slide back and forth. An adjustment cavity is formed in the counterweight block, and an adjustment component is provided in the adjustment cavity. The adjustment component includes an adjustment slider slidably connected to the inner wall of the adjustment cavity and a transmission component for driving the adjustment slider to slide. A balance detection mechanism is provided at the bottom of the forklift. The balance detection mechanism includes two measurement components respectively for detecting the heights of the front side and the rear side of the forklift from the ground and a comparison component for detecting the difference between the measurement values of the two measurement components. The comparison component is electrically connected to a PLC, and the PLC is electrically connected to the moving component and the transmission component.

[0006] Compared with the prior art, the beneficial effects of the present invention are:

[0007] The heights from the front and rear of the forklift to the ground are respectively detected by two measuring components. The two heights are compared by a comparison component. If the front side is closer to the ground, the moving component / adjusting component is controlled by the PLC to move the counterweight / adjusting slider to the rear end of the forklift; if the rear side is closer to the ground, the moving component / adjusting component is controlled by the PLC to move the counterweight / adjusting slider to the front end of the forklift, so as to adjust the center of gravity of the forklift and prevent the forklift from tilting forward and backward; and the counterweight is larger than the adjusting slider and also heavier than the adjusting slider. At the moment of lifting or lowering the goods, the balance change of the forklift is relatively large. Therefore, when the forklift lifts or lowers the goods, the counterweight is used to adjust the balance; during driving, usually when the road surface is uneven or when accelerating / decelerating, an unstable phenomenon occurs. At this time, the unstable phenomenon can be balanced by adjusting the slider.

[0008] Preferably, transmission grooves are formed on both sides of the counterweight. The moving component includes two racks respectively fixed on the inner walls of the two transmission grooves, two gears respectively meshing and driving with the two racks, and a first motor respectively driving the two gears to rotate. The first motor is fixed on the inner wall of the counterweight chute, and the PLC is electrically connected to the first motor.

[0009] Preferably, the two racks are a long rack and a short rack respectively. Among them, the gear meshing with the short rack drives the counterweight to move to the rear side of the forklift, and the gear meshing with the long rack drives the counterweight to move to the front side of the forklift; the length of the long rack is equal to the length of the transmission groove, the length of the short rack is smaller than the length of the transmission groove by the radius of a gear, and the short rack extends from the rear side to the front side of the forklift.

[0010] Preferably, the two measuring components are respectively located at the front and rear ends of the forklift. The measuring component includes a cylinder fixed at the bottom of the forklift, a piston slidably connected to the inner wall of the cylinder, a push rod fixed at the bottom of the piston, a wheel frame fixed at the bottom of the push rod, and a pulley rotatably connected to the wheel frame. A compression spring is sleeved on the push rod, and the other two force-receiving ends of the compression spring are respectively fixed on the wheel frame and the cylinder, and the pulley abuts against the ground.

[0011] Preferably, the comparison component includes an air cavity fixed on the forklift, a conductor slider slidably connected to the air cavity, and first metal sheets fixed at both ends of the air cavity; air pipes for communicating the cylinder with the air cavity are respectively arranged between the front and rear sides of the cylinder and the two air cavities, and the first metal sheets are connected to the PLC through wires.

[0012] Preferably, four second metal sheets are arranged on the inner wall of the air cavity, and the second metal sheets are connected to the PLC through wires; initially, the conductor slider is located at the middle position of the air cavity, and the four second metal sheets are symmetrically distributed in pairs on both sides of the conductor slider.

[0013] Preferably, the transmission assembly includes a screw rod threadedly connected to the adjustment slider and a second motor for driving the screw rod to rotate. The second motor is electrically connected to the PLC. A stop block for preventing the adjustment slider from slipping out is provided at the end of the adjustment cavity, and the stop block is sleeved on the end of the screw rod.

[0014] Preferably, a slide rail assembly is provided at the bottom of the counterweight. The slide rail assembly includes a slide rail fixed to the bottom wall of the counterweight chute and a slider fixed to the bottom of the counterweight. The slider is slidably connected to the slide rail.

[0015] Preferably, a pressing groove is formed at the top of the counterweight, and a roller is rotatably connected in the counterweight chute. The roller abuts against the bottom wall of the pressing groove.

[0016] Preferably, a limiting plate is provided at the rear end of the counterweight. The end face of the limiting plate is larger than the notch of the counterweight chute. When the counterweight is completely located in the counterweight chute, the limiting plate abuts against the rear end of the forklift. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 is a side cross-sectional view of the present invention;

[0019] Figure 3 is Figure 2 a partial enlarged view at "A";

[0020] Figure 4 is Figure 2 a partial enlarged view at "B";

[0021] Figure 5 is Figure 2 a partial enlarged view at "C";

[0022] Figure 6 is Figure 2 a cross-sectional view at "D-D";

[0023] Figure 7 is a schematic diagram of the structure of the counterweight mechanism of the present invention;

[0024] Figure 8 is Figure 7 a rear view of

[0025] In the figure:

[0026] 1. Forklift; 11. Counterweight chute; 2. Counterweight mechanism; 20. Limit plate; 21. Counterweight block; 210. Adjustment cavity; 211. Pressing groove; 212. Transmission groove; 22. Adjustment assembly; 221. Screw; 222. Adjustment slider; 223. Stopper; 224. Second motor; 23. Roller; 24. Slide rail assembly; 241. Slide rail; 242. Sliding part; 25. Moving assembly; 250. Motor fixing plate; 251. First motor; 252. Gear; 253. Rack; 253a. Long rack; 253b. Short rack; 3. Balance detection mechanism; 30. Air pipe; 31. Measuring assembly; 311. Cylinder; 312. Push rod; 313. Piston; 314. Wheel carrier; 315. Compression spring; 316. Pulley; 32. Comparison assembly; 321. Air cavity; 322. Conductor slider; 323. Second metal sheet; 324. First metal sheet. Specific embodiments

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] Please refer to Figures 1-4 , this embodiment provides a forklift counterweight structure, including a balance detection mechanism 3 located at the bottom of the forklift 1. The balance detection mechanism 3 includes two measuring assemblies 31 respectively used to detect the heights of the front side and the rear side of the forklift 1 from the ground, and a comparison assembly 32 used to detect the difference between the measured values of the two measuring assemblies 31. The comparison assembly 32 is electrically connected to a PLC.

[0029] Please refer to Figure 2 , Figure 3 , in this embodiment, the two measuring assemblies 31 are respectively located at the front and rear ends of the forklift 1, and the closer the front measuring assembly 31 is to the head of the forklift 1 and the closer the rear measuring assembly 31 is to the tail of the forklift 1, the better the detection effect. The measuring assembly 31 includes a cylinder 311 fixed to the bottom of the forklift 1, a piston 313 slidably connected to the inner wall of the cylinder 311, a push rod 312 fixed to the bottom of the piston 313, a wheel carrier 314 fixed to the bottom of the push rod 312, and a pulley 316 rotatably connected to the wheel carrier 314. A compression spring 315 is sleeved on the push rod 312, and the other two force-receiving ends of the compression spring 315 are respectively fixed to the wheel carrier 314 and the cylinder 311. The compression spring 315 presses the pulley 316 against the ground.

[0030] Please refer to Figure 2 , Figure 4, in this embodiment, the comparison component 32 includes an air chamber 321 fixedly arranged on the forklift 1, a conductor slider 322 slidably connected to the air chamber 321, and first metal sheets 324 fixedly arranged on the front and rear sides of the air chamber 321. The front and rear sides of the air chamber 321 refer to the front and rear sides relative to the forklift 1. A trachea 30 for connecting the cylinder 311 and the air chamber 321 is arranged between the two ends of the cylinder 311 and the two air chambers 321 respectively. The first metal sheet 324 is connected to the PLC through a wire. When the conductor slider 322 contacts the first metal sheet 324, current passes through the wire, the first metal sheet 324 and the conductor slider 322, and the PLC converts this current into an electrical signal, enabling the PLC to receive the signal that the conductor slider 322 touches the first metal sheet 324. Four second metal sheets 323 are arranged on the inner wall of the air chamber 321, and the second metal sheets 323 are connected to the PLC through wires. Initially, the conductor slider 322 is located at the middle position of the air chamber 321. The four second metal sheets 323 are symmetrically distributed in pairs on both sides of the conductor slider 322. The two second metal sheets 323 on the same side are located on the opposite inner walls of the air chamber 321 (as Figure 4 shown). When the conductor slider 322 contacts the second metal sheet 323, current sequentially passes through the wire connected to the upper second metal sheet 323, the upper second metal sheet 323, the conductor slider 322, the lower second metal sheet 323, and the wire connected to the lower second metal sheet 323. The PLC converts this current into an electrical signal, enabling the PLC to receive the signal that the conductor slider 322 touches the second metal sheet 323. It should be noted that the current flowing into the conductor slider 322 from the first metal sheet 234 is on both sides of the conductor slider 322, and the current flowing into the conductor slider 322 from the second metal sheet 323 is in the middle of the conductor slider 322, and there is an insulator between the two, that is, the current flowing into the conductor slider 322 from the first metal sheet 234 is not connected to the current flowing into the conductor slider 322 from the second metal sheet 323, so there will be no short - circuit phenomenon.

[0031] Please refer to Figure 1 , Figure 2 , Figure 7 , Figure 8, in this embodiment, a counterweight chute 11 is provided at the rear end of the forklift 1. A counterweight mechanism 2 is provided in the counterweight chute 11. The counterweight mechanism 2 includes a counterweight block 21 slidably connected to the inner wall of the counterweight chute 11, and a moving assembly 25 for pushing the counterweight block 21 to slide back and forth. Transmission grooves 212 are formed on both sides of the counterweight block 21. The moving assembly 25 includes two racks 253 (one rack 253 is installed in the inner wall of each of the two transmission grooves 212, for a total of two racks 253), two gears 252 respectively meshing and driving with the two racks 253, and first motors 251 respectively driving the two gears 252 to rotate. The first motors 251 are fixedly arranged on the inner wall of the counterweight chute 11. The PLC is electrically connected to the first motors 251.

[0032] It should be noted that, in order to prevent the counterweight block 21 from moving backward too much, causing the gear 252 to disengage from the rack 253, the two racks 253 are respectively a long rack 253a and a short rack 253b. Among them, the gear 252 meshing with the short rack 253b drives the counterweight block 21 to move to the rear side of the forklift 1, and the gear 252 meshing with the long rack 253a drives the counterweight block 21 to move to the front side of the forklift 1; the length of the long rack 253a is equal to the length of the transmission groove 212, the length of the short rack 253b is smaller than the length of the transmission groove 212 by the radius of one gear 252, and the short rack 253b extends from the rear side to the front side of the forklift 1. Among them, the gear 252 meshing with the short rack 253b drives the counterweight block 21 to move to the rear side of the forklift 1, and the gear 252 meshing with the long rack 253a drives the counterweight block 21 to move to the front side of the forklift 1, which can effectively prevent the counterweight block 21 from moving backward too much, and the gear 252 and the long rack 253a are always meshed.

[0033] In order to fix the first motors 251, a motor fixing plate 250 is provided in the counterweight chute 11, and the first motors 251 are fixedly arranged on the motor fixing plate 250.

[0034] Please refer to Figure 1 、 Figure 2 、 Figure 5 、 Figure 6 , in this embodiment, an adjustment cavity 210 is formed in the counterweight block 21. An adjustment assembly 22 is provided in the adjustment cavity 210. The adjustment assembly 22 includes an adjustment slider 222 slidably connected to the inner wall of the adjustment cavity 210, a screw rod 221 threadedly connected to the adjustment slider 222, and a second motor 224 for driving the screw rod 221 to rotate. A stop block 223 for preventing the adjustment slider 222 from sliding out is provided at the end of the adjustment cavity 210. The stop block 223 is sleeved on the end of the screw rod 221. The adjustment assembly 22 can finely adjust the center of gravity position of the forklift 1 by changing the position of the adjustment slider 222.

[0035] Please refer to Figure 6, in order to prevent the counterweight 21 from shifting in position, resulting in poor meshing between the two gears 252 and the rack 253, in this embodiment, a slide rail assembly 24 is provided at the bottom of the counterweight 21. The slide rail assembly 24 includes a slide rail 241 fixed to the bottom wall of the counterweight chute 11, and a slider 242 fixed to the bottom of the counterweight 21. The slider 242 is slidably connected to the slide rail 241. As can be seen from Figure 6 , the cross-sections of the slide rail 241 and the slider 242 are L-shaped and are snap-connected to each other, so that the counterweight 21 can only slide along the direction of the slide rail 241.

[0036] Please refer to Figures 5-7 , in order to prevent the counterweight 21 from tilting due to gravity after sliding out, in this embodiment, a pressing groove 211 is formed at the top of the counterweight 21, and a roller 23 is rotatably connected in the counterweight chute 11. The roller 23 abuts against the bottom wall of the pressing groove 211, effectively preventing the counterweight 21 from tilting after sliding out of the counterweight chute 11.

[0037] Please refer to Figure 1 , Figure 5 , in this embodiment, a limiting plate 20 is provided at the rear end of the counterweight 21. The end face of the limiting plate 20 is larger than the notch of the counterweight chute 11. When the counterweight 21 is completely located in the counterweight chute 11, the limiting plate 20 abuts against the rear end of the forklift 1.

[0038] The working principle of the balance detection mechanism 3 is as follows. When the forklift 1 tilts forward, the front push rod 312 pushes the piston 313 upward, pushing the gas in the front cylinder 311 into the front trachea 30; the rear push rod 312 drives the piston 313 downward under the action of the compression spring 315, generating negative pressure in the rear cylinder 311, and sucking the gas at the rear side of the air chamber 321 into the rear cylinder 311 through the rear trachea 30; causing the conductor slider 322 to move backward, and the conductor slider 322 will contact the rear second metal sheet 323. If the forklift 1 lifts the goods, it will cause the forklift 1 to suddenly tilt forward. At this time, the conductor slider 322 will not only contact the rear second metal sheet 323, but also contact the rear first metal sheet 324. When the forklift 1 tilts backward, the rear push rod 312 pushes the piston 313 upward, pushing the gas in the rear cylinder 311 into the rear trachea 30; the front push rod 312 drives the piston 313 downward under the action of the compression spring 315, generating negative pressure in the front cylinder 311, and sucking the gas at the front side of the air chamber 321 into the front cylinder 311 through the rear trachea 30; causing the conductor slider 322 to move forward, and the conductor slider 322 will contact the front second metal sheet 323. If the forklift 1 lowers the goods, it will cause the forklift 1 to suddenly tilt backward. At this time, the conductor slider 322 will not only contact the front second metal sheet 323, but also contact the front first metal sheet 324.

[0039] When the forklift 1 picks up a heavy object instantaneously, the forklift 1 will have a large forward tilt instantaneously. The conductor slider 322 will move backward instantaneously and abut against the first metal sheet 324 at the rear side. Current passes through the wire, the first metal sheet 324 at the rear side and the conductor slider 322. At this time, the PLC converts the current into an electrical signal to start the first motor 251. The PLC controls the first motor 251 on the side of the short rack 253b to start, driving the gear 252 to mesh with the short rack 253b, so that the counterweight 21 moves backward until the counterweight 21 moves to the position of front-back balance. At this time, the conductor slider 322 is located at the middle position of the air cavity 321; When the forklift 1 puts down the heavy object instantaneously, the forklift 1 will have a large backward tilt instantaneously. The conductor slider 322 will move forward instantaneously and abut against the first metal sheet 324 at the front side. Current passes through the wire, the first metal sheet 324 at the front side and the conductor slider 322. At this time, the PLC converts the current into an electrical signal to start the first motor 251. The PLC controls the first motor 251 on the side of the long rack 253a to start, driving the gear 252 to mesh with the long rack 253a, so that the counterweight 21 moves forward until the counterweight 21 moves to the position of front-back balance. At this time, the conductor slider 322 is located at the middle position of the air cavity 321.

[0040] During the handling process, if the front-back force is unbalanced, the conductor slider 322 will slide slightly forward and backward under the action of air pressure and will contact the second metal sheet 323 at this time; If a forward tilt occurs, the conductor slider 322 contacts the two second metal sheets 323 at the rear side. Current passes through the second metal sheet 323 at the rear side and the conductor slider 322. The PLC converts the current into an electrical signal to start the second motor 224 to rotate forward. The PLC controls the second motor 224 to rotate forward, so that the screw 221 drives the adjustment slider 222 to move backward; If a backward tilt occurs, the conductor slider 322 contacts the second metal sheet 323 at the front side. Current passes through the second metal sheet 323 at the front side and the conductor slider 322. The PLC converts the current into an electrical signal to start the second motor 224 to rotate reversely. The PLC controls the second motor 224 to rotate reversely, so that the screw 221 drives the adjustment slider 222 to move forward to finely adjust the center of gravity of the forklift 1.

[0041] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. Forklift counterweight structure, characterized in that, It includes a counterweight chute (11) opened at the rear end of a forklift (1). A counterweight mechanism (2) is provided in the counterweight chute (11). The counterweight mechanism (2) includes a counterweight block (21) slidably connected to the counterweight chute (11), and a moving component (25) for pushing the counterweight block (21) to slide back and forth; an adjustment cavity (210) is opened in the counterweight block (21), and an adjustment component (22) is provided in the adjustment cavity (210). The adjustment component (22) includes an adjustment slider (222) slidably connected to the inner wall of the adjustment cavity (210) and a transmission component for driving the adjustment slider (222) to slide; a balance detection mechanism (3) is provided at the bottom of the forklift (1). The balance detection mechanism (3) includes two measurement components (31) respectively for detecting the height from the ground of the front side and the rear side of the forklift (1), and a comparison component (32) for detecting the difference between the measurement values of the two measurement components (31); the comparison component (32) is electrically connected to a PLC, the PLC is electrically connected to the moving component (25), and the PLC is electrically connected to the transmission component.

2. The forklift counterweight structure according to claim 1, characterized in that, Driving grooves (212) are opened on both sides of the counterweight block (21). The moving component (25) includes two racks (253), two gears (252) respectively meshing and driving with the two racks (253), and a first motor (251) respectively driving the two gears (252) to rotate. The first motor (251) is fixed on the inner wall of the counterweight chute (11). The PLC is electrically connected to the first motor (251). One rack (253) is installed in the inner wall of each of the two driving grooves (212), and there are two racks (253) in total.

3. The forklift counterweight structure according to claim 2, characterized in that, The two racks (253) are respectively a long rack (253a) and a short rack (253b). Among them, the gear (252) meshing with the short rack (253b) drives the counterweight block (21) to move towards the rear side of the forklift (1), and the gear (252) meshing with the long rack (253a) drives the counterweight block (21) to move towards the front side of the forklift (1); the length of the long rack (253a) is equal to the length of the driving groove (212), the length of the short rack (253b) is smaller than the length of the driving groove (212) by the radius of one gear (252), and the short rack (253b) extends from the rear side to the front side of the forklift (1).

4. The forklift counterweight structure according to claim 1, characterized in that, The two measurement components (31) are respectively located at the front and rear ends of the forklift (1). The measurement component (31) includes a cylinder (311) fixed at the bottom of the forklift (1), a piston (313) slidably connected to the inner wall of the cylinder (311), a push rod (312) fixed at the bottom of the piston (313), a wheel frame (314) fixed at the bottom of the push rod (312), and a pulley (316) rotatably connected to the wheel frame (314). A compression spring (315) is sleeved on the push rod (312). The other two force-receiving ends of the compression spring (315) are respectively fixed on the wheel frame (314) and the cylinder (311). The pulley (316) abuts against the ground.

5. The forklift counterweight structure according to claim 4, characterized in that, The comparison component (32) includes an air chamber (321) fixed on the forklift (1), a conductor slider (322) slidably connected to the air chamber (321), and first metal sheets (324) fixed at both ends of the air chamber (321); there is an air pipe (30) for connecting the cylinder (311) and the air chamber (321) between the front and rear sides of the cylinder (311) and two air chambers (321) respectively, and the first metal sheet (324) is connected to the PLC through a wire.

6. The forklift counterweight structure according to claim 5, characterized in that, The inner wall of the air chamber (321) is provided with four second metal sheets (323), and the second metal sheets (323) are connected to the PLC through wires; initially, the conductor slider (322) is located at the middle position of the air chamber (321), and the four second metal sheets (323) are symmetrically distributed in pairs on both sides of the conductor slider (322).

7. The forklift counterweight structure according to claim 1, characterized in that, The transmission component includes a screw rod (221) threadedly connected to the adjustment slider (222), and a second motor (224) for driving the screw rod (221) to rotate. The second motor (224) is electrically connected to the PLC. A stop block (223) for preventing the adjustment slider (222) from sliding out is provided at the end of the adjustment cavity (210), and the stop block (223) is sleeved on the end of the screw rod (221).

8. The forklift counterweight structure according to claim 1, characterized in that, The bottom of the counterweight block (21) is provided with a slide rail assembly (24). The slide rail assembly (24) includes a slide rail (241) fixed on the bottom wall of the counterweight chute (11), and a slider (242) fixed on the bottom of the counterweight block (21). The slider (242) is slidably connected to the slide rail (241).

9. The forklift counterweight structure according to claim 1, characterized in that, A pressing groove (211) is formed at the top of the counterweight block (21), and a roller (23) is rotatably connected in the counterweight chute (11). The roller (23) abuts against the bottom wall of the pressing groove (211).

10. The forklift counterweight structure according to claim 1, characterized in that, A limiting plate (20) is provided at the rear end of the counterweight block (21). The end face of the limiting plate (20) is larger than the notch of the counterweight chute (11). When the counterweight block (21) is completely located in the counterweight chute (11), the limiting plate (20) abuts against the rear end of the forklift (1).

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