Resistance detection unit

Abstract

The utility model provides a resistance detection unit, which comprises a floating assembly, a bearing seat, a sensing element and a plurality of elastic sheets, the floating assembly comprises a floating seat and a bolt arranged on the floating seat, the bearing seat is arranged on the floating seat, an installation position of the elastic sheets is formed between the bearing seat and the bolt, and the plurality of elastic sheets are arranged on the installation position in a vertically stacked manner; the floating assembly can float relative to the bearing seat, the elastic piece can generate deformation due to floating, and the sensing element is arranged on the elastic piece located on the surface so as to detect the deformation and output a signal used for judging the resistance condition. The floating of the floating assembly relative to the bearing seat reflects the change of the loading force, the floating assembly, the bearing seat and the elastic piece are all tightly connected in movement and force conduction, the floating assembly directly bears the changed loading force when encountering resistance, the floating assembly floats relative to the bearing seat under the action of the elastic piece, and the elastic piece also deforms, so that the elastic piece is prevented from falling off. And the sensing element receives the deformation quantity.

Description

Technical Field

[0001] The utility model relates to the field of furniture, in particular to an obstruction detection unit. Background Art

[0002] Electric furniture, such as electric beds and electric tables, has functions such as automatic lifting and automatic flipping, which is convenient for users. In order to prevent electric furniture from pinching users during activities, electric furniture is usually equipped with an obstacle retraction function. That is, when the device senses an obstacle during movement, it will immediately move in the opposite direction to avoid the obstacle, thereby preventing damage to the furniture or pinching the user.

[0003] In existing devices for detecting resistance in lifting tables, in order to make the piezoelectric piece more sensitive, the elasticity of the component that carries the piezoelectric piece is often increased. There is also a solution to set the piezoelectric piece on a spring piece. However, even if the piezoelectric piece is set on the spring piece, its sensitivity is still poor, which is mainly reflected in the small difference between the signal waveform generated during normal operation and the signal waveform generated when encountering resistance. Therefore, it is not conducive to the control unit to make resistance judgments. Summary of the Invention

[0004] In order to solve the above technical problems, the utility model provides an obstruction detection unit, including a floating assembly, a bearing seat, a sensing element and a plurality of spring pieces, the floating assembly includes a floating seat and a bolt arranged thereon, the bearing seat is placed on the floating seat, and an installation position of the spring piece is formed between the bearing seat and the screw, and a plurality of spring pieces are stacked up and down and arranged at the installation position; the floating assembly can float relative to the bearing seat, and the spring piece will generate a deformation amount due to the floating, and the sensing element is arranged on the spring piece located on the surface to detect the deformation amount and output a signal for judging the obstruction situation; the floating assembly is relative to the bearing seat The floating of the seat reflects the change of the load force. The floating component, the bearing seat and the spring are closely connected in terms of movement and force transmission. When encountering resistance, the floating component is directly affected by the changed load force, and floats relative to the bearing seat under the action of the spring, and the spring is also deformed, so that the sensing element receives the deformation; the spring with the sensing element mainly outputs the deformation to the sensing element, and the other springs are responsible for bearing the main load force. Therefore, the functions of multiple springs are different, and each performs its own duties, so that the solution of multiple springs can ensure sufficient load-bearing capacity, while also improving the sensitivity and accuracy of resistance detection.

[0005] The technical solution of the present utility model is achieved as follows:

[0006] An obstruction detection unit, comprising:

[0007] The floating assembly includes a floating seat and a bolt disposed on the floating seat, the bolt having a head located at an upper end thereof; the floating assembly is configured to float in response to a change in load force when encountering resistance;

[0008] The bearing seat is placed on the floating seat, and a mounting position is formed between the bearing seat and the bolt head;

[0009] A plurality of spring sheets are stacked up and down and arranged at an installation position, and a bolt passes through all the spring sheets so that the spring sheets are located at the installation position; the spring sheets are configured to generate a deformation amount according to the floating of the floating assembly;

[0010] The sensing element is arranged on the spring sheet located on the surface and is configured to output a signal for judging an obstruction situation according to the deformation amount of the spring sheet.

[0011] After stacking, one spring element will be on the surface, with the other spring elements located between it and the mounting location. The sensing element is directly mounted on the spring element on the surface, making installation easy. The floating movement of the floating assembly relative to the support base reflects changes in the load force. The floating assembly, support base, and spring elements are closely connected in terms of movement and force transmission. When encountering resistance, the floating assembly is directly affected by the changed load force, causing it to float relative to the support base under the action of the spring elements. The spring elements are also deformed, causing the sensing element to receive this deformation. The spring elements with sensing elements mainly output the deformation to the sensing elements, while the other spring elements are responsible for bearing the main load force. Therefore, the functions of the multiple spring elements are different, each performing its own duties. This allows the multiple spring element solution to ensure sufficient load capacity while also improving the sensitivity and accuracy of resistance detection.

[0012] Preferably, there is a gap between the floating seat and the bearing seat. When resistance occurs, the change in load force causes the floating seat to float, and the size of the gap changes, which also reflects the deformation of the spring, so that the sensing element can sufficiently detect the deformation of the spring when resistance occurs.

[0013] Preferably, the bearing seat is provided with a relief hole, through which a bolt passes to connect to the floating seat. An elastic member is also provided in the relief hole, with its ends respectively contacting the spring clip and the floating seat. When resistance is encountered, the bearing seat and the floating seat float relative to each other. Furthermore, due to the connection between the bolt and the floating seat, the bearing seat and the bolt also float relative to each other, and the spring clip in the installed position is deformed by the action of the bolt head and the bearing seat.

[0014] Preferably, the elastic member is a silicone or rubber pad.

[0015] Preferably, the bearing seat is provided with a receiving groove at the mounting position, and in the vertical direction, the spring piece close to the bearing seat abuts against the end surface of the receiving groove, and the spring piece close to the head abuts against the head. The presence of the receiving groove facilitates the installation of the spring piece in the mounting position between the bearing seat and the bolt.

[0016] Preferably, the end surface of the receiving groove abuts against the outer ring portion of the spring sheet, and the head abuts against the inner ring portion of the spring sheet. When the floating assembly floats, the head acts on the spring sheet, causing the inner ring portion of the spring sheet to deform relative to the outer ring portion.

[0017] Preferably, a deformation groove is further provided on the end surface of the receiving groove. The deformation groove is configured so that when the inner ring portion of the spring sheet deforms under the action of the bolt head, the deformation groove avoids the spring sheet. The presence of the receiving groove can also reduce the overall thickness of the resistance detection unit, allowing the spring sheet to be stably mounted on the support seat. When the bolt passes from top to bottom through the opening of the spring sheet, the inner ring portion of the spring sheet deforms downward, and the deformation groove avoids the inner ring portion of the spring sheet.

[0018] Preferably, the plurality of spring fragments include a signal spring fragment and at least one load-bearing spring fragment. The signal spring fragment is configured as a plurality of spring fragments stacked and positioned on a surface for mounting a sensing element. The load-bearing spring fragment is positioned between the signal spring fragment and the mounting location, and is configured to bear a load. A single spring fragment is replaced by multiple spring fragments, with at least two spring fragments having different functions: the signal spring fragment is used to output a deformation variable to the sensing element, and the load-bearing spring fragment is used to bear the load. The signal spring fragment and the load-bearing spring fragment have clear divisions of labor and perform their respective functions. The load-bearing spring fragment bears most of the load for the signal spring fragment without affecting the deformation of the signal spring fragment. That is, after the load-bearing spring fragment bears the main load, the signal spring fragment is less affected by the load size and its changes, thereby enabling the signal spring fragment to have a more accurate, stable, and sensitive deformation variable output. The sensing element generates a signal based on the deformation variable of the signal spring fragment, thereby making the resistance retraction detection more accurate, sensitive, and stable.

[0019] Preferably, the thickness of the signal shrapnel is thinner than that of the load-bearing shrapnel. A thinner signal shrapnel is more conducive to deformation and has a stronger deformation capacity, thereby making the signal output by the sensing element more sensitive and accurate. A thicker load-bearing shrapnel can more stably bear most loads, minimizing the impact of excessive loads or load changes on the signal shrapnel's deformation capacity.

[0020] Preferably, the sensing element is a piezoelectric sheet. Using a piezoelectric sheet as a sensing element can effectively detect the deformation of the spring, is easy to implement and has low cost.

[0021] The design starting point, concept and beneficial effects of the utility model using the above technical solution are:

[0022] After stacking, one spring element will be on the surface, with the other spring elements located between it and the mounting location. The sensing element is directly mounted on the spring element on the surface, making installation easy. The floating movement of the floating assembly relative to the support base reflects changes in the load force. The floating assembly, support base, and spring elements are closely connected in terms of movement and force transmission. When encountering resistance, the floating assembly is directly affected by the changed load force, causing it to float relative to the support base under the action of the spring elements. The spring elements are also deformed, causing the sensing element to receive this deformation. The spring elements with sensing elements mainly output the deformation to the sensing elements, while the other spring elements are responsible for bearing the main load force. Therefore, the functions of the multiple spring elements are different, each performing its own duties. This allows the multiple spring element solution to ensure sufficient load capacity while also improving the sensitivity and accuracy of resistance detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the three-dimensional structure of the lifting column in the embodiment of the present utility model;

[0024] Figure 2 This is a cross-sectional view of the lifting column in an embodiment of the present utility model;

[0025] Figure 3 This is a schematic diagram of the three-dimensional structure of the transmission assembly, the end plate and the resistance detection device in the embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the three-dimensional structure of the gear box, end plate and resistance detection device in an embodiment of the present invention;

[0027] Figure 5 This is a side view of the gear box, end plate and resistance detection device in an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the three-dimensional structure of the bolts and the end plate in the embodiment of the present utility model;

[0029] Figure 7 This is a schematic diagram of the three-dimensional structure of the bearing seat and the gear box abutting in the embodiment of the present invention;

[0030] Figure 8 This is a waveform diagram of a single spring in the first set of experiments in the embodiment of the present invention;

[0031] Figure 9 This is a waveform diagram of the double springs in the first group of experiments in the embodiment of the present invention;

[0032] Figure 10 This is a waveform diagram of a single spring in the second group of experiments in the embodiment of the present invention;

[0033] Figure 11This is a waveform diagram of the double springs in the second group of experiments in the embodiment of the present invention;

[0034] Figure 12 This is a waveform diagram of a single spring in the third group of experiments in the embodiment of the present invention;

[0035] Figure 13 This is a waveform diagram of the double springs in the third group of experiments in the embodiment of the present invention;

[0036] Figure 14 This is a waveform diagram of a single spring in the fourth group of experiments in the embodiment of the present invention;

[0037] Figure 15 This is a waveform diagram of the double springs in the fourth group of experiments in the embodiment of the present invention;

[0038] Figure 16 is a cross-sectional view of the resistance detection unit when not working in the embodiment of the present invention;

[0039] Figure 17 This is a cross-sectional view of the floating seat moving downward when the floating seat encounters resistance in the embodiment of the utility model;

[0040] Figure 18 This is a cross-sectional view of the floating seat moving upward when encountering resistance when descending in the embodiment of the utility model.

[0041] The figures are marked as follows: supporting seat 1; mounting plate 101; protrusion 102; bolt 2; head 201; threaded portion 202; sensing element 3; signal spring 4; supporting spring 5; sleeve 6; transmission assembly 7; gear box 71; end plate, floating seat 8; opening 9; accommodating groove 10; deformation groove 11; connecting hole 12; gap 13; avoidance hole 14; elastic member 15. DETAILED DESCRIPTION

[0042] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other without conflict.

[0043] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0044] In the description of the present invention, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0045] The specific implementation of the utility model is as follows:

[0046] like Figure 1 、 3 As shown, the utility model provides an obstruction detection unit, comprising:

[0047] The floating assembly includes a floating seat 8 and a bolt 2 disposed on the floating seat 8, wherein the bolt 2 has a head 201 located at an upper end thereof; the floating assembly is configured to float in response to a change in load force when encountering resistance;

[0048] The bearing seat 1 is placed on the floating seat 8, and a mounting position is formed between the bearing seat 1 and the head of the bolt 2;

[0049] A plurality of spring sheets are stacked up and down and arranged at the installation position, and a bolt 2 passes through all the spring sheets so that the spring sheets are located at the installation position; the spring sheets are configured to generate a deformation amount according to the floating of the floating assembly;

[0050] The sensing element 3 is provided on the spring sheet located on the surface and is configured to output a signal for determining an obstruction situation according to the deformation amount of the spring sheet.

[0051] After stacking, one spring element will be located on the surface, with the other spring elements positioned between it and the mounting location. The sensing element 3 is positioned directly on the spring element located on the surface, facilitating installation. The floating movement of the floating assembly relative to the support base 1 reflects changes in the load force. The floating assembly, support base 1, and spring elements are closely connected in terms of movement and force transmission. When encountering resistance, the floating assembly is directly subjected to the changed load force, causing the spring elements to float relative to the support base 1. This deformation of the spring elements causes the sensing element 3 to detect this deformation.

[0052] Specifically, in this embodiment, there are two springs, namely a signal spring 4 and a load-bearing spring 5. The load-bearing seat 1 is configured to be connected to the transmission assembly 7 of the lifting column, and the bolt 2 is configured to be connected to the sleeve 6 of the lifting column and transfer the load to the signal spring 4 and the load-bearing spring 5; the bolt 2 passes through the signal spring 4 and the load-bearing spring 5 from top to bottom and transfers the load to the signal spring 4 and the load-bearing spring 5; the sensing element 3 is arranged on the signal spring 4, and the load-bearing spring 5 is configured to bear the load. The signal spring 4 is configured to generate deformation when the load of the load-bearing spring 5 changes, and the sensing element 3 is configured to output a signal for judging the resistance situation according to the deformation amount of the signal spring 4; when the load changes, the load transmitted by the bolt 2 to the signal spring 4 and the load-bearing spring 5 changes, and the signal spring 4 and the load-bearing spring 5 generate corresponding deformation amounts. The sensing element 3 detects the deformation amount of the signal spring 4 and outputs a signal for judging the resistance situation.

[0053] A double spring sheet is used instead of a single spring sheet. The two spring sheets have different functions. The signal spring sheet 4 is used to output the deformation of the sensing element 3, and the load-bearing spring sheet 5 is used to bear the load. The signal spring sheet 4 and the load-bearing spring sheet 5 have clear division of labor and each performs its own function. The load-bearing spring sheet 5 bears most of the load for the signal spring sheet 4, but does not affect the deformation of the signal spring sheet 4. That is, after the load-bearing spring sheet 5 bears the main load, the influence of the load size and its changes on the signal spring sheet 4 is reduced, thereby making the signal spring sheet 4 have a more accurate, stable and sensitive deformation output. The sensing element 3 generates a signal according to the deformation of the signal spring sheet 4, so that the resistance retreat detection is more accurate, sensitive and stable.

[0054] The resistance detection device is applied to a lifting column, such as Figure 1-3 As shown, the lifting column includes a telescopic sleeve 6, a transmission assembly 7 that drives the sleeve 6 to extend and retract, and the aforementioned resistance detection device. The transmission assembly 7 is disposed within the sleeve 6. The sleeve 6 has an end plate 8 at its upper end, which has an opening 9 through which the transmission assembly 7 is exposed. The resistance detection device is mounted on the sleeve 6, with the bolt 2 connected to the end plate 8, and the mounting plate 101 connected to the transmission assembly 7 through the opening 9. In this embodiment, the transmission assembly 7 is connected to the support base 1, and the bolt 2 is connected to the end plate 8. When resistance occurs, a slight relative movement occurs between the transmission assembly 7 and the end plate 8, thereby causing the support base 1 and the bolt 2 to float relative to each other. Since the signal spring 4 and the bearing spring 5 are mounted on the support base 1 under the action of the bolt 2, when the support base 1 and the bolt float relative to each other, the signal spring 4 and the bearing spring 5 deform, allowing the sensing element 3 to detect the deformation of the signal spring 4, thereby achieving resistance detection. The end plate 8 is the floating seat 8.

[0055] The sensing element 3 is a piezoelectric sheet, which is annular and is attached to the upper surface of the signal shrapnel 4. The annular sensing element 3 can also avoid the bolt 2 in the middle. Using a piezoelectric sheet as the sensing element 3 can effectively detect the deformation of the signal shrapnel 4, is easy to implement and has low cost.

[0056] like Figure 3-6 As shown, the bolt 2 also has a threaded portion 202 with a diameter smaller than the head 201. The bolt 2 passes through the signal shrapnel 4 and the load-bearing shrapnel 5 from top to bottom. The head 201 can apply a pre-tightening force to the signal shrapnel 4 and the load-bearing shrapnel 5, and the threaded portion 202 can be threadedly connected to the end plate 8; the signal shrapnel 4 and the load-bearing shrapnel 5 are both annular sheets with an opening in the center. The bolt 2 passes through the opening from top to bottom, so the main deformation position of the signal shrapnel 4 and the load-bearing shrapnel 5 is located near the center of the circle.

[0057] The bearing seat 1 includes a mounting plate 101 and a convex portion 102 protruding downward from the mounting plate 101. A recessed receiving groove 10 is provided on the mounting plate 101. The bearing spring 5 is arranged in the receiving groove 10. The lower surface of the bearing spring 5 abuts against the receiving groove 10. The signal spring 4 rests on the upper surface of the bearing spring 5. The sensing element 3 is attached to the upper surface of the signal spring 4. The head 201 of the bolt 2 abuts against the signal spring 4. The bottom surface of the receiving groove 10 is also provided with a recessed deformation groove 11. The deformation groove 11 is provided with a plurality of grooves. 1 is located at the center of the accommodating groove 10. The deformation groove 11 is configured so that when the supporting spring piece 5 deforms downward, the deformation groove 11 can avoid the supporting spring piece 5. More specifically, when the supporting spring piece 5 deforms downward, the portion of the supporting spring piece 5 near the opening deforms downward, that is, the inner ring portion deforms downward, and the deformation groove 11 can avoid the supporting spring piece 5. The presence of the accommodating groove 10 can reduce the overall thickness of the resistance detection device and also facilitate the positioning and installation of the supporting spring piece 5, allowing the supporting spring piece 5 to be stably set on the supporting base 1. The end surface of the accommodating groove 10 abuts the outer ring portion of the spring piece, and the head abuts the inner ring portion of the spring piece. The bottom surface of the accommodating groove 10 is the end surface of the accommodating groove 10.

[0058] Furthermore, in order to realize the resistance detection specifically, the deformation of the signal spring piece 4 and the bearing spring piece 5 must be realized first. If the deformation of the signal spring piece 4 and the bearing spring piece 5 is realized, the movement of the bearing seat 1 and the bolt 2 must be realized first. Specifically, if Figure 2-7As shown, the transmission assembly 7 includes a gear box 71 and a screw nut assembly at the upper end, a connecting hole 12 is opened in the middle position of the bearing seat 1, and the connecting hole 12 passes through the mounting plate 101 and the protrusion 102 in the vertical direction, the lower end of the bearing seat 1 abuts on the gear box 71 and is connected to the gear box 71 by arranging a bolt in the connecting hole 12, so as to realize the synchronous movement of the bearing seat 1 and the transmission assembly 7; wherein, the protrusion 102 abuts on the gear box 71 of the transmission assembly 7 downward from the opening 9; and in the vertical direction, there are gaps 13 between the gear box 71 of the transmission assembly 7 and the end plate 8, and between the mounting plate 101 and the end plate 8; moreover, an avoidance hole 14 passing through the mounting plate 101 is opened on the bottom surface of the deformation groove 11, and an elastic member 15 is provided in the avoidance hole 14, the bolt 2 is inserted in the elastic member 15, and the upper end of the elastic member 15 abuts against the bearing spring piece 5, and the elastic member The lower end of 15 abuts against the end plate 8; giving the bearing seat 1 and the end plate 8 the ability to float relative to each other is equivalent to giving the bearing seat 1 and the bolt 2 the ability to float relative to each other; when resistance occurs, a small relative movement occurs between the transmission assembly 7 and the end plate 8 of the sleeve 6. Since the bearing seat 1 is connected to the transmission assembly 7, under the action of the elastic member 15, relative floating can also occur between the bearing seat 1 and the end plate 8. Since the bolt 2 is connected to the end plate 8, the bearing seat 1 and the bolt 2 also float relatively. Under the action of the bolt 2 and the bearing seat 1, the signal spring piece 4 and the bearing spring piece 5 are deformed; the elastic member 15 abuts against the bearing spring piece 5, and can also more intuitively give the deformation result of the bearing spring piece 5 after the bearing seat 1 floats, and can also prevent the signal spring piece 4 and the bearing spring piece 5 from excessive deformation and creep, thereby weakening the effect of resistance detection; in addition, the elastic member 15 is a silicone or rubber cushion.

[0059] The gap 13 between the transmission assembly 7 and the end plate 8 and the gap 13 between the mounting plate 101 and the end plate 8 allow the transmission assembly 7 and the end plate 8 to float up and down, and the mounting plate 101 can also float up and down relative to the end with the transmission assembly 7, so that the mounting plate 101 is equivalent to the bolt 2 connected to the end plate 8 floating up and down, causing deformation of the signal spring piece 4 and the load-bearing spring piece 5.

[0060] In order to achieve bidirectional resistance detection, during installation, the head 201 of the bolt 2 needs to apply pre-tightening force to the signal spring piece 4 and the load spring piece 5, so that the signal spring piece 4 abuts against the bolt 2, and the load spring piece 5 abuts against the receiving groove. During installation, the bolt 2 passes through the signal spring piece 4 and the load spring piece 5 from top to bottom and applies pre-tightening force to the signal spring piece 4 and the load spring piece 5, such as Figure 16-18 As shown, when the floating seat 8 floats upward, the elastic member will give the spring piece an upward deformation, and when the floating seat 8 floats downward, the head will give the spring piece a downward deformation, thereby achieving the effect of two-way resistance detection.

[0061] In addition, in order to further enhance the effect of clear division of labor of the double shrapnel, the thickness of the signal shrapnel 4 is smaller than the thickness of the load-bearing shrapnel 5. When the thicker load-bearing shrapnel 5 is located below the signal shrapnel 4, the load-bearing shrapnel 5 can share most of the load for the signal shrapnel 4, allowing the signal shrapnel 4 to focus on deformation; the signal shrapnel 4 is thinner, more conducive to deformation, and has a stronger deformation ability, thereby making the signal output by the sensing element 3 more sensitive and accurate; the load-bearing shrapnel 5 is thicker, and can bear most of the load more stably, minimizing the impact of excessive load or load changes on the deformation ability of the signal shrapnel 4.

[0062] Furthermore, the supporting base 1 has two installation positions for springs, that is, two groups of signal springs 4, supporting springs 5 ​​and sensing elements 3 are provided on the supporting base 1, and the supporting base 1 is obliquely placed on the end plate 8, and the two groups of signal springs 4, supporting springs 5 ​​and sensing elements 3 are diagonally arranged on the end, so as to obtain a more accurate resistance detection signal.

[0063] The traditional single-shrapnel method is improved to a double-shrapnel method, which greatly improves the performance of resistance detection: the bolt 2 applies a pre-tightening force to the signal shrapnel 4 and the load-bearing shrapnel 5. When the bolt 2 is lifted from rest to normal lifting, the force (load) transmitted by the bolt 2 to the signal shrapnel 4 and the load-bearing shrapnel 5 changes, and the signal shrapnel 4 and the load-bearing shrapnel 5 are deformed. Among them, the load-bearing shrapnel 5 bears the main role of bearing the load, and the signal shrapnel 4 bears the role of giving the sensing element 3 a deformation variable. The sensing element 3 converts the detected deformation variable into a signal value and transmits it to the control unit. If the signal value is less than the trigger threshold for retreating when encountering resistance, the lifting table continues to work; when the lifting table goes from normal lifting to encountering resistance, The force (load) transmitted by the bolt 2 to the signal shrapnel 4 and the load-bearing shrapnel 5 is further changed, and the load-bearing shrapnel 5 still bears the main load, reducing the influence of the load size and its changes on the signal shrapnel 4, thereby having a more accurate, stable and sensitive deformation output. Therefore, the sensing element 3 generates a signal value according to the deformation of the signal shrapnel 4 and transmits it to the control unit. At this time, the signal value is greater than the trigger threshold, and the control unit controls the lifting table to retreat when encountering resistance; due to the design of double shrapnel, the deformation and signal value are more accurate, stable and sensitive. Compared with the existing technology, the signal value when encountering resistance can significantly exceed the trigger threshold, making the retreat when encountering resistance more accurate, sensitive and stable.

[0064] During installation, the bearing seat 1 is set on the end plate 8, and its lower end is in contact with the gear box 71. The bolt 2 passes through the spring plate and the bearing seat 1 from top to bottom and is locked on the end plate 8. Since the lower end of the bearing seat 1 is in contact with the gear box 71, the force balance is maintained. Therefore, under normal circumstances, the whole is in force balance.

[0065] First, the macroscopic movement is decomposed into a series of tiny movements. For example, the single lifting of the lifting table, that is, the extension of the column, is achieved by the gear box repeatedly pushing up the end plate. Then, from a microscopic perspective, focus on the tiny movements of the components around the shrapnel to analyze the lifting table's rise, fall, resistance when rising, and resistance when falling. Figure 16-18 As shown:

[0066] When the lifting table rises, the gear box 71 floats upward, and the gear box 71 pushes up the supporting base 1, and the bolt 2 remains stationary. Under the limit of the head of the bolt 2, the spring piece is deformed, and the sensing element 3 detects the deformation of the spring piece at this time and generates the basic waveform when rising; when the lifting table encounters resistance during the rising process, while the gear box 71 floats upward, the end plate 8 is subjected to a downward load force, and the end plate 8 and the bolt 2 both float downward, and the head 201 of the bolt 2 further deforms the spring piece. At this time, the sensing element 3 detects a larger deformation of the spring piece, and generates an resistance waveform with a larger peak than the basic waveform. The control unit can easily determine that resistance has occurred.

[0067] When the lifting table descends, when the gear box 71 floats downward, the screws between the gear box 71 and the supporting base 1 drive the supporting base 1 to float downward. After the elastic deformation of the spring piece, its elastic force can drive the elastic part 15 and the end plate 8 to float downward. The sensing element 3 detects the deformation of the spring piece at this time and generates a basic waveform during descent; when the lifting table encounters resistance during the descent process, while the gear box 71 floats downward, the end plate 8 is subjected to an upward load force, and the end plate 8, the elastic part 15 and the bolt 2 all float upward. The elastic part 15 gives the spring piece an upward deformation. Similarly, the sensing element 3 generates a resistance waveform with a larger peak than the basic waveform, and the control unit can easily determine that resistance has occurred.

[0068] The sensing element 3 transmits the signal value to the control unit at all times, so a wave is formed, such as Figure 8 、 9 As shown, no matter when stationary, rising or falling normally or when encountering resistance, the wave formed in the single-shrapnel form will be smoother than the wave formed in the double-shrapnel form. Especially when encountering resistance, the difference between the wave crest generated by the single-shrapnel resistance device and the normal situation is smaller, which makes it difficult to break through the trigger threshold, and the sensitivity and accuracy of resistance detection are poor. The double-shrapnel resistance device has a larger wave crest, which solves this problem and makes resistance detection more sensitive and accurate.

[0069] In order to further illustrate the superior effect of the double spring clip, resistance experiments were carried out on two identical lifting tables using a single spring clip and a double spring clip respectively, and the experimental data were compared; in this experiment, a single spring clip with a thickness of 1.8mm was selected and the experimental data was transmitted by it, and a double spring clip with a thickness of 0.6mm+1.2mm was selected, and the experimental data was transmitted by a spring clip with a thickness of 0.6mm. Four groups of comparative experiments were carried out. In the first group of experiments, the lifting table was empty and ascended; in the second group of experiments, the lifting table descended with a load of 10kg, and the 10kg load was removed to restore the empty load, to simulate the situation where the lifting table encountered resistance when descending; in the third group of experiments, the lifting table was loaded with a load of 20kg and ascended; in the fourth group of experiments, the lifting table descended with a load of 30kg, and the 10kg load was removed to restore the load to 20kg, to simulate the situation where the lifting table encountered resistance when descending. After the above four groups of experiments, the waveforms generated by the four groups of experiments were obtained, and the experimental data were obtained. In the waveform diagram, the horizontal coordinate represents time, in ms or s, and the vertical coordinate represents the piezoelectric signal value generated by the deformation of the spring, in mv; the waveform of the experiment is as follows Figure 8-15 The experimental data table is shown below:

[0070]

[0071]

[0072]

[0073]

[0074] The first and third groups of experiments are both experiments under normal rising conditions of the lifting table. For reference, the maximum value represents the maximum value of the piezoelectric signal waveform, and the minimum value represents the minimum value of the piezoelectric signal waveform; in the second and fourth groups of experiments, the maximum value before removal represents the maximum value of the piezoelectric signal waveform under normal working conditions, and the maximum value after removal represents the maximum value of the piezoelectric signal waveform generated when resistance occurs. The larger the difference between the two, the more conducive it is to judging whether resistance occurs; from the second group of experiments, it can be seen that when a single spring element encounters resistance, the peak difference generated is 72, and when a double spring element encounters resistance, the peak difference generated is 240, which is significantly greater than that of a single spring element, which means that the double spring element is easier to judge the occurrence of resistance, that is, the sensitivity of resistance detection is better; similarly, in the fourth group of experimental data, the peak difference generated by a single spring element when resistance occurs is 116, and the peak difference generated by a double spring element when resistance occurs is 261. The double spring element is also easier to judge the occurrence of resistance, and the sensitivity of resistance detection is better.

Claims

1. An obstruction detection unit, characterized in that: include: The floating assembly includes a floating seat and a bolt disposed on the floating seat, the bolt having a head located at an upper end thereof; the floating assembly is configured to float in response to a change in load force when encountering resistance; The bearing seat is placed on the floating seat, and a mounting position is formed between the bearing seat and the bolt head; A plurality of spring sheets are stacked up and down and arranged at an installation position, and a bolt passes through all the spring sheets so that the spring sheets are located at the installation position; the spring sheets are configured to generate a deformation amount according to the floating of the floating assembly; The sensing element is arranged on the spring sheet located on the surface and is configured to output a signal for judging an obstruction situation according to the deformation amount of the spring sheet.

2. The obstruction detection unit according to claim 1, characterized in that: There is a gap between the floating seat and the bearing seat.

3. The resistance detection unit according to claim 2, wherein: An avoidance hole is provided on the bearing seat, and the bolt passes through the avoidance hole and is connected to the floating seat. An elastic member is also provided in the avoidance hole, and two ends of the elastic member are respectively in contact with the spring piece and the floating seat.

4. The obstruction detection unit according to claim 3, characterized in that: The elastic member is a silicone or rubber pad.

5. The resistance detection unit according to claim 1, wherein: The supporting seat is provided with a receiving groove at the installation position. In the up and down directions, the elastic piece close to the supporting seat abuts against the end surface of the receiving groove, and the elastic piece close to the head abuts against the head.

6. The resistance detection unit according to claim 5, characterized in that: The end surface of the accommodating groove abuts against the outer ring portion of the elastic piece, and the head abuts against the inner ring portion of the elastic piece.

7. The resistance detection unit according to claim 5, characterized in that: A deformation groove is also provided on the end surface of the accommodating groove. The deformation groove is configured so that when the inner ring portion of the spring piece is deformed under the action of the head of the bolt, the deformation groove avoids the spring piece.

8. The resistance detection unit according to claim 1, characterized in that: The multiple springs include a signal spring and at least one load-bearing spring. The signal spring is configured as multiple springs stacked and located on the surface for mounting the sensing element. The load-bearing spring is located between the signal spring and the mounting position and is configured to carry a load.

9. The obstruction detection unit according to claim 8, characterized in that: The thickness of the signal shrapnel is smaller than the thickness of the load-bearing shrapnel.

10. The resistance detection unit according to claim 1, characterized in that: The sensing element is a piezoelectric piece.

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