Adjustable heavy-load constant force device

Abstract

The invention discloses an adjustable heavy-load constant force device which comprises a shell, an elastic assembly, a swing arm assembly, a constant force adjusting assembly, a tail end output plate and a steel wire rope. The elastic assembly is connected with the swing arm assembly through a steel wire rope, the elastic assembly is used for providing elastic force changing along with displacement of the output end and mainly comprises a guide mechanism and an adjusting mechanism, and the adjusting mechanism comprises an adjusting plate; the swing arm assembly mainly comprises a swing arm supporting seat, a connecting rod and a plastic-coated bearing; the tail end of the steel wire rope is fixedly connected with the movable end of the connecting rod; the constant force adjusting assembly comprises an installation base, a motor, a lead screw nut mechanism and a synchronous belt transmission mechanism, the position of an adjusting plate in the elastic assembly is changed through the transmission mechanism, and accurate adjustment of the output constant force can be achieved. The device has the advantages of being simple in structure, high in reliability, adjustable in output constant force and high in engineering applicability, and has wide application prospects.

Description

Technical Field

[0001] This invention relates to a constant force loading device, and more particularly to an adjustable large load constant force device. Background Technology

[0002] A constant force mechanism is a mechanical device that uses its own geometric structure to output a constant force within a certain deformation range. It is widely used in mechanical engineering, mechanisms and robotics, and aerospace.

[0003] Existing constant force control methods mainly fall into two categories: active control and passive compensation. Active control can achieve precise force control through sensing and feedback systems, but its system structure is complex, large in size, and costly. Passive constant force mechanisms rely on the mechanical properties of the mechanism itself to achieve constant force output. Among them, compliant constant force mechanisms are more common in the fields of mechanisms and robotics, but their design methods are complex, their load-bearing capacity is limited, and their practicality is insufficient. In the aerospace field, rigid constant force mechanisms are often used for gravity compensation to verify spacecraft performance, but existing structures generally suffer from insufficient load-bearing capacity and non-adjustable output constant force.

[0004] Therefore, developing a constant force mechanism with a compact structure, strong load capacity, and precisely adjustable output constant force has significant engineering application value and broad application prospects. Summary of the Invention

[0005] In view of the above-mentioned prior art, the present invention provides a heavy-duty constant force device with simple structure, high reliability, strong load capacity and adjustable output constant force, so as to solve the problems existing in the above-mentioned existing constant force mechanisms.

[0006] To solve the above-mentioned technical problems, this invention proposes an adjustable large-load constant force device, comprising a housing, an elastic component, a swing arm assembly, a constant force adjustment component, an end output plate, and a steel wire rope; the elastic component includes a guiding mechanism and an adjustment mechanism; the guiding mechanism includes an adjustment guide rail fixed to the front panel of the housing and adjustment sliders A and B slidably connected to the adjustment guide rail; the adjustment mechanism includes a guide shaft and an adjustment plate fixed to the adjustment slider A, a movable pulley support is fixed to the adjustment slider B by bolts, a fixed pulley is mounted on the adjustment plate through a fixed pulley support, the adjustment plate has a through hole, the upper end of the guide shaft is slidably connected to the adjustment plate through the through hole, a compression spring is fitted on the guide shaft, a compression spring base is provided at the lower end of the guide shaft, a movable pulley is mounted on the compression spring base through a movable pulley support; the stroke of the adjustment mechanism is limited by the limiting block; the swing arm... The assembly includes a swing arm support, a connecting rod, and a pair of coaxial plastic-coated bearings. The swing arm support is fixedly mounted on the front panel of the housing. One end of the connecting rod is rotatably connected to the swing arm support, and the plastic-coated bearing is mounted on the other end of the connecting rod. The constant force adjustment assembly includes a mounting base fixed above the front panel of the housing. A motor is mounted on the mounting base. The motor drives a lead screw and nut mechanism via a synchronous belt drive mechanism. The lead screw and nut mechanism includes a lead screw, the upper end of which is fixed to the driven pulley of the synchronous belt drive mechanism. A lead screw nut, which is fixed to the adjustment plate, meshes with the lead screw. The lower end of the lead screw is supported by a lead screw support on the bottom plate of the housing. The end output plate is slidably connected to one side plate of the housing. The end output plate maintains contact with the circumferential surface of the plastic-coated bearing of the swing arm assembly. A steel wire rope connects the elastic component and the swing arm assembly.

[0007] Furthermore, in the adjustable large-load constant force device of the present invention:

[0008] The adjusting plate is provided with a fixing pin, and the fixing pin is provided with a radial hole. One end of the wire rope is fixed to the adjusting plate through the radial hole, and the other end of the wire rope passes through the movable pulley and the fixed pulley in sequence and is connected to one end of the connecting rod.

[0009] The side of the adjustment plate is provided with an indicator ear, and the housing is provided with a vertical through groove that is aligned with the indicator ear on the side plate close to the indicator ear.

[0010] The end output plate includes a load plate located outside the side plate of the housing. The load plate is an angle plate structure, and the angle plate includes a vertical back plate and a horizontal plate. The side plate of the housing is provided with the vertical output guide rail, and the back plate is provided with an output slider that slides with the output guide rail. An output plate is fixed on the output slider. The output plate has a fork-shaped opening in the middle position. The width of the fork-shaped opening is greater than the width of the movable end of the connecting rod. Two vertical through slots are provided on the side plate of the housing at positions corresponding to the two ends of the fork-shaped opening of the output plate. The output plate passes through the through slots to achieve a sliding connection with the side plate of the housing.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] The adjustable high-load constant force device of the present invention can achieve constant force output from the end output plate by reasonably selecting the stiffness and length parameters of the compression spring in the elastic component and the dimensions of the connecting rod in the swing arm component. The position of the adjusting plate in the elastic component can be adjusted by the constant force adjusting component, thereby changing the magnitude of the output force. When the position of the adjusting plate is not changed, the output force is constant; changing the position alters the magnitude of the output force. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the adjustable high-load constant force device of the present invention;

[0014] Figure 2 for Figure 1 A schematic diagram of the structure of the housing 1 shown in the figure;

[0015] Figure 3 for Figure 1 A schematic diagram of the structure of the elastic component 2 shown in the figure;

[0016] Figure 4 for Figure 1 A schematic diagram of the structure of the swing arm assembly 3 shown in the figure;

[0017] Figure 5 for Figure 1 A schematic diagram of the structure of the constant force adjustment component 4 shown in the figure;

[0018] Figure 6 for Figure 1 The diagram shows the structure of the end output board 5.

[0019] Figure label:

[0020] 1-Housing, 11-Vertical through slot, 12-Terminal block, 13-Diverter, 14-Limit switch, 15-Limit stop, 16-Support side screw support, 2-Elastic component, 21-Guide mechanism, 211-Adjusting guide rail, 212a-Adjusting slider A, 212b-Adjusting slider B, 22-Adjusting mechanism, 221-Adjusting plate, 222-Fixing pin, 223-Indicator lug, 224-Fixed pulley support, 225-Fixed pulley, 226-Moving pulley support, 227-Compression spring base, 228-Moving pulley, 229-Guide shaft, 2210-Compression Spring, 3-Swing arm assembly, 31-Swing arm support, 32-Connecting rod, 33-Pin, 331-Through hole, 34-Flange bearing, 35-Plastic coated bearing, 4-Constant force adjustment assembly, 41-Motor, 42-Mounting base, 43-Synchronous belt drive mechanism, 431-Motor output shaft, 432a-Driving wheel, 432a-Driving wheel, 433-Synchronous belt, 434-Fixed side screw support, 435-Screw, 436-Screw nut, 5-End output plate, 51-Output guide rail, 52-Output slider, 53-Output plate, 54-Load plate, 6-Wire rope. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention.

[0022] like Figure 1 As shown, the present invention provides an adjustable large load constant force device, including a housing 1, an elastic component 2, a swing arm component 3, a constant force adjustment component 4, an end output plate 5, and a steel wire rope 6.

[0023] like Figure 2 As shown, the housing 1 can be made of aluminum alloy and has a box-type structure. The housing 1 includes a front panel, two side panels, and a bottom plate, which are used to support and position the internal components. A limit stop 15 is provided on the upper inner wall of the front panel of the housing 1 to limit the stroke of the adjustment mechanism 22 in the elastic component 2. A stroke stop and a limit switch 14 are provided on the inner wall of the side panel on the same side as the end output plate 5 of the housing 1, which are used for limiting and detecting the stroke of the end output plate 5 and can be used as a condition for judging the adjustment state of the device. A terminal block 12 is provided on the side panel on the other side of the housing 1, and a splitter 13 is provided on the lower inner wall of the front panel of the housing 1. The terminal block 12 and the splitter 13 are used to connect the motor output line and the limit switch signal line. A support side screw support 16 is provided on the bottom plate to maintain the straightness requirement of the screw 435 in the constant force adjustment component 4, while allowing a certain degree of axial freedom.

[0024] like Figure 3As shown, the elastic component 2 includes a guide mechanism 21 and an adjustment mechanism 22; the guide mechanism 21 includes an adjustment guide rail 211 and two adjustment sliders. The adjustment guide rail 211 is fixed to the front panel of the housing 1 by bolts, and the two adjustment sliders, namely adjustment slider A 212a and adjustment slider B 212b, are slidably connected to the adjustment guide rail 211. The adjusting mechanism 22 includes a guide shaft 229 and an adjusting plate 221 fixed to the adjusting slider A 212a. A movable pulley support 226 is bolted to the adjusting slider B 212b. The adjusting plate 221 has a vertical through hole. The upper end of the guide shaft 229 is slidably connected to the adjusting plate 221 through this vertical through hole. A compression spring 2210 is fitted onto the guide shaft 229. A compression spring base 227 is provided at the lower end of the guide shaft 229. The lower end of the compression spring 2210 abuts against the compression spring base 227, and the upper end of the compression spring 2210 abuts against the adjusting plate 221 to prevent longitudinal bending deformation of the compression spring 2210 during compression. The compression spring base 227 and the movable pulley 228 are coaxially fixedly mounted on the movable pulley support 226. The adjusting mechanism 22 can move synchronously along the adjusting guide rail 211 with the adjusting sliders A 212a and B 212b. The adjusting plate 221 is provided with a fixing pin 222, which has a radial hole for securing the wire rope 6. The side of the adjusting plate 221 is provided with an indicator lug 223. A vertical through groove 11, aligned with the indicator lug 223, is provided on the side plate of the housing 1 closest to the indicator lug 223. This vertical through groove allows direct observation of the position of the adjusting plate 221 from outside the housing 1, thereby determining the output force. A fixed pulley support 224 is fixed to the adjusting plate 221, and a fixed pulley 225 is mounted on the fixed pulley support 224.

[0025] like Figure 4 As shown, the swing arm assembly 3 includes a swing arm support 31, a connecting rod 32, and a pair of coaxial plastic-coated bearings 35. The swing arm support 31 is fixedly installed on the front panel of the housing 1. Both ends of the connecting rod 32 are equipped with flange bearings 34. One end of the connecting rod 32 is rotatably connected to the swing arm support 31. The other side of the connecting rod 32 is hinged to a pin 33. The pin 33 has a through hole in the middle for fixing the end of the wire rope 6.

[0026] like Figure 5As shown, the constant force adjustment component 4 includes a mounting base 42 fixed above the front panel of the housing 1. A motor 41 and a fixed-side lead screw support 434 are mounted on the mounting base 42. The motor output shaft 431 drives a lead screw and nut mechanism via a synchronous belt transmission mechanism 43. The synchronous belt transmission mechanism 43 includes a driving pulley 432a, a driven pulley 432b, and a synchronous belt 433. The mounting base 42 has a slotted hole for tensioning the synchronous belt 433. The lead screw and nut mechanism includes a lead screw 4... 35. The upper end of the lead screw 435 is installed in the fixed-side lead screw support 434. The driving wheel 432a and the driven wheel 432b are respectively fixed to the upper end of the motor output shaft 431 and the lead screw 435 through set screws. The lead screw 435 is engaged with a lead screw nut 436 fixed to the adjusting plate 221. The lower end of the lead screw 435 is supported by the support-side lead screw support 16 set on the bottom plate of the housing 1. The lead screw 435 can rotate with the inner ring of the fixed-side lead screw support 434. The motor 41 drives the lead screw 435 to rotate through the synchronous belt transmission mechanism 43. The lead screw 435 and the lead screw nut 436 cooperate to convert the rotational motion of the lead screw 435 into the linear motion of the lead screw nut 436. Since the lead screw nut 436 is fixed to the adjusting plate 221, the linear motion of the lead screw nut 436 drives the adjusting plate 221 to move up and down, thereby changing the distance between the adjusting plate 221 and the swing arm support 31, and realizing precise adjustment of the output constant force.

[0027] like Figure 1 As shown, the end output plate 5 is slidably connected to one side plate of the housing 1, and one end of the end output plate 5 located on the inner wall of the side plate maintains contact with the circumferential surface of the plastic-coated bearing 35 of the swing arm assembly 3; as Figure 1 , Figure 2 and Figure 6The end output plate 5 shown includes a load plate 54 located outside the side plate of the housing 1. The load plate 54 is an angle plate structure, which includes a vertical back plate and a horizontal plate. The side plate of the housing 1 is provided with the vertical output guide rail 51, and the back plate is provided with an output slider 52 that slides with the output guide rail 51. The output slider 52 can move linearly along the direction of the output guide rail 51. The load plate 54 is fixed to the output slider 52 by a threaded connector. An output plate 53 is also fixed to the output slider 52 by a threaded connector. The output plate 53 has a fork-shaped opening in the middle, and the width of the fork-shaped opening is greater than the width of the movable end of the connecting rod 32. Two vertical through slots are provided on the side plate of the housing, corresponding to the two ends of the fork-shaped opening of the output plate. The output plate 53 passes through the through slots to achieve a sliding connection with the side plate of the housing. At the same time, the output plate 53 and the load plate 54 can move synchronously with the output slider 52. When the swing arm assembly 3 acts on the output plate 53, the plastic-coated bearing 35 in the swing arm assembly 3 contacts and engages with the output plate 53, and the potential energy stored in the compression spring is transferred to the end output plate 5 by the steel wire rope 6. Under the condition that the load plate 54 bears the external load, constant force compensation can be achieved for the load acting on the load plate 54.

[0028] like Figure 1 As shown, the steel wire rope 6 connects the elastic component 2 and the swing arm assembly 3. Specifically, one end of the steel wire rope 6 is fixed to the adjusting plate 221 through a radial hole on the fixing pin 222, and the other end of the steel wire rope 6 passes sequentially around the movable pulley 228 and the fixed pulley 225 to change the direction of force transmission. Finally, it passes through the through hole of the pin 33 located at the movable end of the connecting rod 32, and is fixed to the pin 33 by bolts. A pair of plastic-coated bearings 35 in the swing arm assembly 3 are respectively installed at both ends of the pin 33 and always form a rolling contact with the output plate 53, using the steel wire rope 6 to transfer the elastic potential energy stored in the compression spring 23 to the swing arm assembly 3. When the load plate 54 is subjected to an external load, the swing arm assembly 3 can provide a compensating force to the load plate 54 in the opposite direction and with a basically constant magnitude, thereby achieving constant force compensation for the load acting on the load plate 54.

[0029] When the load plate 54 is displaced under external load, the swing arm assembly 3 rotates around the swing arm support 31, simultaneously driving the movable pulley 228 to passively generate a compensating motion opposite to the displacement direction of the output plate 53, so as to maintain a constant output force. Given a fixed spring constant of the compression spring 23, the magnitude of the constant output force depends only on the distance between the fixed pulley 225 and the swing arm support 31.

[0030] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many improvements and changes under the guidance of the present invention without departing from the spirit of the present invention, and these improvements and changes are all within the protection scope of the present invention.

Claims

1. An adjustable high-load constant force device, comprising a housing (1), an elastic component (2), a swing arm component (3), a constant force adjustment component (4), an end output plate (5), and a steel wire rope (6), characterized in that, The elastic component (2) includes a guide mechanism (21) and an adjustment mechanism (22); the guide mechanism (21) includes an adjustment guide rail (211) fixed to the front panel of the housing (1) and adjustment sliders A (212a) and B (212b) slidably connected to the adjustment guide rail (211); the adjustment mechanism (22) includes a guide shaft (229) and an adjustment plate (221) fixed to the adjustment slider A (212a); a movable pulley support (226) is fixed to the adjustment slider B (212b) by bolts; the adjustment plate (212a) is fixed to the adjustment slider B (212b) by bolts. 21) A fixed pulley (225) is installed on the fixed pulley support (224). The adjusting plate (221) is provided with a through hole. The upper end of the guide shaft (229) is slidably connected to the adjusting plate (221) through the through hole. A compression spring (2210) is fitted on the guide shaft (229). A compression spring base (227) is provided at the lower end of the guide shaft (229). A movable pulley (228) is installed on the compression spring base (227) through the movable pulley support (226). The stroke of the adjusting mechanism (22) is limited by the limiting block (15). The swing arm assembly (3) includes a swing arm support (31), a connecting rod (32), and a pair of coaxial plastic-coated bearings (35); the swing arm support (31) is fixedly installed on the front panel of the housing (1), one end of the connecting rod (32) is rotatably connected to the swing arm support (31), and the plastic-coated bearings (35) are installed on the other end of the connecting rod (32); The constant force adjustment component (4) includes a mounting base (42) fixed above the front panel of the housing (1). A motor (41) is mounted on the mounting base (42). The motor (41) drives a lead screw nut mechanism through a synchronous belt transmission mechanism. The lead screw nut mechanism includes a lead screw (435). The upper end of the lead screw (435) is fixed to the driven wheel of the synchronous belt transmission mechanism. A lead screw nut (436) fixed to the adjustment plate (221) is engaged on the lead screw (435). The lower end of the lead screw (435) is supported by a support-side lead screw support (16) provided on the bottom plate of the housing (1). The end output plate (5) is slidably connected to one side plate of the housing (1), and the end output plate (5) is in contact with the circumferential surface of the plastic-coated bearing (35) of the swing arm assembly (3); The wire rope (6) is connected between the elastic component (2) and the swing arm component (3).

2. The adjustable large-load constant force device according to claim 1, characterized in that, The adjusting plate (221) is provided with a fixing pin (222), and the fixing pin (222) is provided with a radial hole. One end of the wire rope (6) is fixed to the adjusting plate (221) through the radial hole, and the other end of the wire rope (6) passes through the movable pulley (228) and the fixed pulley (225) in sequence and is connected to one end of the connecting rod (32).

3. The adjustable large-load constant force device according to claim 1, characterized in that, The side of the adjustment plate (221) is provided with an indicator ear (223), and the housing (1) is provided with a vertical through groove (11) aligned with the indicator ear (223) on the side plate close to the indicator ear (223).

4. The adjustable large-load constant force device according to claim 1, characterized in that, The end output plate (5) includes a load plate (54) located outside the side plate of the housing (1). The load plate is an angle plate structure, and the angle plate includes a vertical back plate and a horizontal plate. The side plate of the housing (1) is provided with the vertical output guide rail (51). The back plate is provided with an output slider (52) that slides with the output guide rail (51). An output plate (53) is fixed on the output slider (52). A fork-shaped opening is provided in the middle of the output plate. The width of the fork-shaped opening is greater than the width of the movable end of the connecting rod (32). Two vertical through slots are provided on the side plate of the housing, at positions corresponding to the two ends of the fork-shaped opening of the output plate. The output plate (53) passes through the through slots to achieve a sliding connection with the side plate of the housing.

5. The adjustable large-load constant force device according to claim 4, characterized in that, The output slider (52) slides with the output guide rail (51), and the output plate (53) and the load plate (54) move synchronously with the output slider (52). When the swing arm assembly (3) acts on the output plate (53), the load plate (54) is subjected to external load, and constant force compensation is achieved for the load acting on the load plate (54).

6. The adjustable large-load constant force device according to claim 1, characterized in that: The housing (1) has a limit block (15) on the upper part of the inner wall of the front panel for limiting the travel of the adjustment mechanism (22); the housing (1) has a travel block and a travel switch (14) on the inner wall of the side plate on the same side as the end output plate (5) for limiting and detecting the travel of the end output plate (5); the housing (1) has a terminal block (12) on the side plate that is close to the motor (42); the housing (1) has a splitter (13) on the lower part of the inner wall of the front panel of the housing (1); the terminal block (12) and the splitter (13) are used to connect the motor output line and the travel switch signal line.

7. The adjustable large-load constant force device according to claim 1, characterized in that, By reasonably selecting the stiffness and length parameters of the compression spring (2210) and the size of the connecting rod (32), the constant force output of the end output plate (5) can be achieved.

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