Nonlinear force measuring device

Abstract

The utility model provides a nonlinear force measuring device, and relates to the field of dynamometers. The non-linear force measuring device comprises a fixed chassis and a sliding block, the surface of the fixed chassis is rotatably connected with two rotating shafts, the surface of each rotating shaft is fixedly connected with a force measuring spring, the two force measuring springs are fixedly connected with the sliding block, the surface of the sliding block is fixedly connected with a tension bar, and the tension bar is fixedly connected with the sliding block. And the bottom end of the tension rod is fixedly connected with a tension hook. According to the nonlinear force measuring device, a heavy object is hung through a tension hook, a tension rod pulls a sliding block to move, two groups of force measuring springs are pulled through the sliding block, reverse tension is provided for the sliding block through elastic tension of the force measuring springs, a force pointer is driven to move through the sliding block, and scales corresponding to the surface of a force scale panel, the non-linear force measuring device is sensitive to small force, can measure a small force and can also measure a large force, and the force measuring range is widened.

Description

Technical Field

[0001] The utility model relates to a force measuring device, in particular to a nonlinear force measuring device, belonging to the technical field of dynamometers. Background Art

[0002] An instrument that uses the elasticity of metal to make a scale to measure the magnitude of force is called a "dynamometer". Dynamometers have various structural forms, but their main parts are bent elastic steel sheets or spiral springs. When external force causes the elastic steel sheet or spring to deform, the pointer is driven to rotate through a transmission mechanism such as a lever. The position where the pointer stops on the dial is the value of the external force.

[0003] The utility model with patent number CN219455345U relates to the technical field of physical experimental instruments, and particularly to a spring dynamometer, wherein the front plate and the shell are detachably connected via two first connecting parts, the first connecting part comprising a first buckle, a button slider and a reset spring, the shell being provided with a first buckle groove and a slider groove, one end of the first buckle is fixedly connected to the front plate and the other end can be slidably inserted into the first buckle groove, the button slider can be slidably inserted into the slider groove, one end of the reset spring is fixedly connected to the slider groove and the other end is fixedly connected to the button slider, the button slider having a first position of clamping the first buckle and a second position of making the buckle movable by squeezing the reset spring, and the clamping cooperation of the first buckle and the button slider effectively improves the assembly strength between the front plate and the shell, prevents the front plate from moving, prevents the scale from not corresponding to the pointer, and reduces the reading error.

[0004] Mechanics experiments are common experiments in middle schools and universities, and spring dynamometers are needed in the experiments. The device in the above patent is insensitive to smaller forces because the direction of the spring is consistent with the direction of the pulling force, and the small-range dynamometer cannot test larger forces. It is difficult to test both a smaller force and a larger force in a spring dynamometer. Therefore, we provide a nonlinear force measuring device to solve the above problems. Utility Model Content

[0005] 1. Technical issues to be resolved

[0006] The purpose of the present utility model is to provide a nonlinear force measuring device in order to solve the above problems, so as to solve the problem in the reference document that it is difficult to measure a smaller force and a larger force in the same force measuring instrument.

[0007] (II) Technical solution

[0008] The utility model is realized through the following technical scheme: a nonlinear force measuring device.

[0009] It includes a fixed chassis and a sliding block. The surface of the fixed chassis is rotatably connected to two rotating shafts. The surface of each rotating shaft is fixedly connected to a force measuring spring, and the two force measuring springs are fixedly connected to the sliding block. The surface of the sliding block is fixedly connected to a tension rod, and the bottom end of the tension rod is fixedly connected to a tension hook.

[0010] Preferably, a force scale panel is fixedly connected to the surface of the fixed chassis, a force pointer is fixedly connected to the surface of the sliding block, and the force pointer is slidably connected to the force scale panel. The scale corresponding to the surface of the force scale panel is read by the force pointer to obtain the measured force value.

[0011] Preferably, a sliding groove is opened in the middle of the fixed chassis, and the sliding block slides inside the sliding groove, a lifting ring is fixedly connected to the top of the fixed chassis, and a level indicator is fixedly connected to the surface of the fixed chassis. The position of the sliding block is fixed through the sliding groove so that the sliding block can only move along the center line of the fixed chassis.

[0012] Preferably, a sliding ring is fixedly connected to the bottom end of the fixed chassis, and the bottom end of the tension rod passes through the sliding ring and is slidably connected to the sliding ring. The sliding ring reduces the friction between the tension rod and the fixed chassis, thereby reducing the error during force measurement.

[0013] Preferably, a protective shell is hinged on the surface of the fixed chassis, and a fixing mechanism is provided on the surface of the fixed chassis. The fixing mechanism includes a rotating pressure plate, and the rotating pressure plate is hinged to the fixed chassis, and the device on the surface of the fixed chassis is protected by the protective shell.

[0014] Preferably, a fixed slot is provided on the surface of the protective shell, a fixed buckle is fixedly connected to the surface of the rotating pressure plate, and the fixed buckle is adapted to the fixed slot, and the protective shell is fixed to the surface of the fixed chassis by snapping the fixed buckle and the fixed slot together.

[0015] Preferably, a support spring is fixedly connected to the surface of the rotating pressure plate, and one end of the support spring away from the rotating pressure plate is fixedly connected to the fixed chassis, and the support spring enables the fixed buckle and the fixed slot to be more tightly engaged.

[0016] The utility model provides a nonlinear force measuring device, which has the following beneficial effects:

[0017] 1. The nonlinear force measuring device hangs a heavy object through a tension hook, so that the tension rod pulls the sliding block to move, and the sliding block pulls two sets of force measuring springs. The elastic tension of the force measuring springs provides a reverse pulling force to the sliding block, and the accurate force value is obtained according to the moving distance of the sliding block. The nonlinear spring dynamometer is sensitive to smaller forces and can test a smaller force as well as a larger force, thereby improving the range of force measurement.

[0018] 2. The nonlinear force measuring device drives the force pointer to slide on the surface of the force scale panel by sliding the sliding block up and down. The force pointer reads the scale corresponding to the surface of the force scale panel to obtain the measured force value. The position of the sliding block is fixed by the sliding groove so that the sliding block can only move along the center line of the fixed chassis, so that the force measuring spring is more evenly stressed, thereby improving the accuracy of the force measurement of the device. The position of the tension rod is fixed by the sliding ring, and the friction between the tension rod and the fixed chassis is reduced, thereby reducing the error during force measurement and improving the accuracy of force measurement.

[0019] 3. The nonlinear force measuring device protects the device on the surface of the fixed chassis through a protective shell to prevent damage to the force measuring spring caused by external force, thereby improving the accuracy of the force measurement of the device. The protective shell is fixed to the surface of the fixed chassis by clamping the fixed buckle and the fixed slot together to prevent the protective shell from loosening and improve the stability of the device operation. The supporting spring provides thrust to the rotating pressure plate to make the fixed buckle and the fixed slot clamped more tightly. Through the horizontal indicator, the user can understand whether the fixed chassis is vertical, reduce the influence of external force during use, and improve the accuracy of force measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0021] Figure 2 It is a partial cross-sectional view of the utility model;

[0022] Figure 3 For this utility model Figure 1 A-section structure enlarged view

[0023] Figure 4 This is a schematic diagram of the force scale plate of the utility model;

[0024] Figure 5 It is a schematic diagram of the displacement relationship curve of the utility model.

[0025]

Main component symbol description

[0026] 1. Fixed chassis; 2. Force scale panel; 3. Sliding slot; 4. Sliding block; 5. Force pointer; 6. Tension rod; 7. Tension hook; 8. Rotating shaft; 9. Force measuring spring; 10. Protective shell;

[0027] 11. Fixing mechanism; 1101. Rotating pressure plate; 1102. Fixing buckle; 1103. Fixing slot; 1104. Support spring;

[0028] 12. Lifting ring; 13. Sliding ring; 14. Level indicator. DETAILED DESCRIPTION

[0029] The embodiment of the utility model provides a nonlinear force measuring device.

[0030] See also Figure 1 and Figure 2 , including a fixed chassis 1 and a sliding block 4, a protective shell 10 is hinged on the surface of the fixed chassis 1, a fixing mechanism 11 is arranged on the surface of the fixed chassis 1, the fixing mechanism 11 includes a rotating pressure plate 1101, and the rotating pressure plate 1101 is hinged to the fixed chassis 1, and the device on the surface of the fixed chassis 1 is protected by the protective shell 10 to avoid damage to the force measuring spring 9 caused by external force, thereby improving the accuracy of the force measurement of the device.

[0031] Please refer again Figure 1 and Figure 3 A fixed slot 1103 is provided on the surface of the protective shell 10, and a fixed buckle 1102 is fixedly connected to the surface of the rotating pressure plate 1101, and the fixed buckle 1102 is adapted to the fixed slot 1103. The fixed buckle 1102 and the fixed slot 1103 are snapped together to fix the protective shell 10 on the surface of the fixed chassis 1, thereby preventing the protective shell 10 from loosening and improving the stability of the device operation.

[0032] A support spring 1104 is fixedly connected to the surface of the rotating pressure plate 1101, and one end of the support spring 1104 away from the rotating pressure plate 1101 is fixedly connected to the fixed chassis 1. The support spring 1104 provides a thrust to the rotating pressure plate 1101, so that the fixed buckle 1102 and the fixed slot 1103 are more tightly connected, preventing the protective shell 10 from swinging at will.

[0033] A tension rod 6 is fixedly connected to the surface of the sliding block 4, and a tension hook 7 is fixedly connected to the bottom end of the tension rod 6. A heavy object is hung through the tension hook 7 so that the tension rod 6 pulls the sliding block 4 to move, and an accurate force value is obtained according to the moving distance of the sliding block 4.

[0034] The bottom end of the fixed chassis 1 is fixedly connected with a sliding ring 13, and the bottom end of the tension rod 6 passes through the sliding ring 13 and is slidingly connected with the sliding ring 13. The sliding ring 13 is used to fix the position of the tension rod 6, and reduce the friction between the tension rod 6 and the fixed chassis 1, thereby reducing the error during force measurement and improving the accuracy of force measurement.

[0035] The surface of the fixed chassis 1 is rotatably connected to two rotating shafts 8, and the surface of each rotating shaft 8 is fixedly connected to a force measuring spring 9, and the two force measuring springs 9 are fixedly connected to the sliding block 4. The two groups of force measuring springs 9 are pulled by the sliding block 4, and the elastic tension of the force measuring springs 9 provides a reverse pulling force to the sliding block 4, and an accurate force value is obtained according to the moving distance of the sliding block 4.

[0036] A force scale panel 2 is fixedly connected to the surface of the fixed chassis 1, a force pointer 5 is fixedly connected to the surface of the sliding block 4, and the force pointer 5 is slidably connected to the force scale panel 2. The sliding block 4 slides up and down, driving the force pointer 5 to slide on the surface of the force scale panel 2. The scale corresponding to the surface of the force scale panel 2 is read by the force pointer 5 to obtain the measured force value.

[0037] A sliding groove 3 is provided in the middle of the fixed chassis 1, and the sliding block 4 slides inside the sliding groove 3. A lifting ring 12 is fixedly connected to the top of the fixed chassis 1, and a level indicator 14 is fixedly connected to the surface of the fixed chassis 1. The position of the sliding block 4 is fixed through the sliding groove 3, so that the sliding block 4 can only move along the center line of the fixed chassis 1, so that the force measuring spring 9 is more evenly stressed, thereby improving the accuracy of the force measurement of the device. Through the lifting ring 12, it is convenient for personnel to use the device, and through the level indicator 14, the user can understand whether the fixed chassis 1 is vertical, thereby reducing the influence of external force during use and improving the accuracy of force measurement.

[0038] The embodiment is set as follows: two rotating shafts 8 are A and B, the sliding block 4 is O, the midpoint of A and B is C, ∠AOC=∠BOC=θ, two springs AO and BO of the same length and elastic coefficient are installed symmetrically, points A and B are fixed, the two springs are connected at point O, and the center line of the system is CO. When a force F is applied downward along the center line CO at point O, the spring will deform.

[0039] Assume that the elastic coefficient of the spring is k, ∠AOC=∠BOC=θ, in the initial state, the initial length of the spring is l0, the angle between the spring and the center line CO ∠AOC=∠BOC=θ0, then the initial length of CO is l0cosθ0, AC=BC=l0sinθ0, take point O as the origin, establish a downward x-axis, after point O is subjected to the downward force F, the new coordinate of point O is x, and the elastic forces in the two springs are FOA and FOB respectively. F, FOA, FOB, CO, BO, θ are regarded as functions of x, that is, F(x), FOA(x), FOB(x), CO(x), BO(x), θ(x). In any state, there is the following set of equations (1) consisting of geometric relationships, physical relationships and the equilibrium relationship of the upward force on x:

[0040]

[0041] Solving equation (1), we can obtain

[0042]

[0043] This is a nonlinear function.

[0044] See also Figure 5, taking k = 1N / mm, l0 = 50mm, θ0 = 80°, the curve of Fx can be obtained from formula (2), which is obviously nonlinear. When F is less than 10N, a small force is applied, and the hook of the dynamometer produces a large deformation, that is, the hook of the dynamometer is easy to pull; when F is greater than 10N, the curve is close to a straight line, that is, the hook of the dynamometer becomes difficult to pull, and the reference values ​​are shown in the figure below.

[0045] F / N x / mm 0.1 4.3 1 6.6 2 9 3 11.3 4 13.4 5 15.5 6 17.4 7 19.2 8 20.8 9 22.4 10 23.9 12 26.7 14 29.1 16 31.3 18 33.2 20 35 25 38.9 30 42,2 35 45.5 40 48.8 45 52.3 50 55.9 60 63.1

[0046] See also Figure 4 , the x value corresponding to the key F value can be obtained by formula (2). According to the F value and x value in the scale value table, the scale value can be marked at a specific position on the panel of the nonlinear spring dynamometer. This nonlinear spring dynamometer is sensitive to smaller forces and can test a smaller force as well as a larger force.

[0047] When the utility model is in use: the fixed chassis 1 is lifted up through the lifting ring 12 to keep the device in a vertical state; the device is determined to be vertical by observing the horizontal indicator 14 to reduce the error during force measurement; a heavy object is hung through the tension hook 7 to make the tension rod 6 pull the sliding block 4 to move; two groups of force measuring springs 9 are pulled through the sliding block 4; a reverse pulling force is provided to the sliding block 4 through the elastic pulling force of the force measuring spring 9 to make the sliding block 4 hover on the surface of the force scale panel 2; the scale corresponding to the surface of the force scale panel 2 is read through the force pointer 5 to obtain the measured force value; the nonlinear spring dynamometer is sensitive to smaller forces and can test a smaller force as well as a larger force, thereby improving the force measuring range of the dynamometer.

[0048] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. A nonlinear force measuring device, comprising a fixed chassis (1) and a sliding block (4), characterized in that: The surface of the fixed chassis (1) is rotatably connected to two rotating shafts (8), the surface of each rotating shaft (8) is fixedly connected to a force measuring spring (9), and the two force measuring springs (9) are fixedly connected to the sliding block (4), the surface of the sliding block (4) is fixedly connected to a tension rod (6), and the bottom end of the tension rod (6) is fixedly connected to a tension hook (7).

2. The nonlinear force measuring device according to claim 1, characterized in that: A force pointer (5) is fixedly connected to the surface of the sliding block (4), and the force pointer (5) is slidably connected to the force scale panel (2).

3. The nonlinear force measuring device according to claim 1, characterized in that: A sliding groove (3) is provided in the middle of the fixed chassis (1), and the sliding block (4) slides inside the sliding groove (3). A lifting ring (12) is fixedly connected to the top of the fixed chassis (1), and a level indicator (14) is fixedly connected to the surface of the fixed chassis (1).

4. The nonlinear force measuring device according to claim 1, characterized in that: The bottom end of the fixed chassis (1) is fixedly connected to a sliding ring (13), and the bottom end of the tension rod (6) passes through the sliding ring (13) and is slidably connected to the sliding ring (13).

5. The nonlinear force measuring device according to claim 1, characterized in that: A protective shell (10) is hingedly connected to the surface of the fixed chassis (1), and a fixing mechanism (11) is provided on the surface of the fixed chassis (1). The fixing mechanism (11) comprises a rotating pressure plate (1101), and the rotating pressure plate (1101) is hingedly connected to the fixed chassis (1).

6. The nonlinear force measuring device according to claim 5, characterized in that: A fixed card slot (1103) is provided on the surface of the protective shell (10), a fixed buckle (1102) is fixedly connected to the surface of the rotating pressure plate (1101), and the fixed buckle (1102) is adapted to fit the fixed card slot (1103).

7. The nonlinear force measuring device according to claim 5, characterized in that: A support spring (1104) is fixedly connected to the surface of the rotating pressure plate (1101), and one end of the support spring (1104) away from the rotating pressure plate (1101) is fixedly connected to the fixed chassis (1).

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