CN213239281U

CN213239281U - Force sensor assembly and engineering machinery

Info

Publication number: CN213239281U
Application number: CN202022097941.5U
Authority: CN
Inventors: 刘延斌; 郭伦文; 文杰; 付玲; 罗贤智; 蒋凯歌; 丁龙; 赵建阳
Original assignee: Zoomlion Heavy Industry Science and Technology Co Ltd
Current assignee: Zoomlion Heavy Industry Science and Technology Co Ltd
Priority date: 2020-09-22
Filing date: 2020-09-22
Publication date: 2021-05-18
Anticipated expiration: 2030-09-22

Abstract

The embodiment of the utility model provides a atress sensor assembly and engineering machine tool belongs to the engineering machine tool field. The force sensor assembly includes: the upper surface of the bearing area is used for bearing the load applied by the structure to be tested; a fixed region for mechanical connection with a structure under test, wherein the fixed region is disposed around the load-bearing region; the strain sensitive area is positioned below the fixed area and is provided with a cavity, and one or more groups of strain gauges are arranged on the inner wall of the cavity, wherein each group of strain gauges form a bridge circuit; and the supporting area is positioned below the strain sensitive area to play a supporting role, wherein the fixing area enables the stress sensor assembly to be mechanically connected with the structure to be measured through a transition connector structure, and at least one part of the upper surface of the fixing area is in clearance fit with the transition connector structure. The provision of a clearance fit may keep only the load bearing zone from bearing the load and avoid the fixing zone from bearing the load partially.

Description

Force sensor assembly and engineering machinery

Technical Field

The utility model relates to an engineering machine tool field specifically relates to a atress sensor assembly and engineering machine tool.

Background

In mechanical structures, force measurements are often necessary. For example, in a construction machine, it is necessary to measure a leg reaction force.

In order to improve the anti-overturning capability of engineering machinery (such as an automobile crane, a pump truck, a fire truck and the like) during operation, a supporting leg supporting structure generally extends to the periphery, and the supporting force of the supporting structure directly reflects the current supporting safety condition of the engineering truck, for example: (1) when the counter force of any supporting leg is larger than the designed bearing limit of the supporting leg, the supporting leg has the risk of instability and failure, and the whole machine has the possibility of rollover accidents; (2) when the counter force of any supporting leg is close to the bearing capacity of the ground, the supporting ground has a collapse and settlement risk, and the engineering machinery can be tipped over; (3) when the counter force of any supporting leg is close to zero, the supporting leg is indicated to generate a 'virtual leg', and construction potential safety hazards exist; (4) more seriously, when the counter force of any two adjacent supporting legs is close to zero, the engineering machinery has serious risk of overturning and instability. Therefore, it is very important to accurately monitor the counter force of the supporting leg of the engineering machinery in real time.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a stress sensor subassembly and engineering machine tool is one kind can with survey structural machine be connected, neotype stress sensor subassembly.

In order to achieve the above object, an embodiment of the present invention provides a force sensor assembly, the force sensor assembly includes: the upper surface of the bearing area is used for bearing the load applied by the structure to be tested; a fixed region for mechanical connection with a structure under test, wherein the fixed region is disposed around the load-bearing region; the strain sensitive area is positioned below the fixed area and is provided with a cavity, and one or more groups of strain gauges are arranged on the inner wall of the cavity, wherein each group of strain gauges form a bridge circuit; and the supporting area is positioned below the strain sensitive area to play a supporting role, wherein the fixing area enables the stress sensor assembly to be mechanically connected with the structure to be measured through a transition connector structure, and at least one part of the upper surface of the fixing area is in clearance fit with the transition connector structure.

Optionally, the support region is provided with an annular groove.

Optionally, the inner section of the annular groove is in the shape of a circular arc, the height of the annular groove is 1/10-1/2 of the diameter of the support region, and the necking diameter of the annular groove is 1/5-9/10 of the diameter of the support region.

Optionally, the opening of the annular groove faces horizontally outwards.

Optionally, the strain sensitive region is a cylindrical strain sensitive region, preferably a cylindrical strain sensitive region; and/or the supporting area is of a ball head type, and the supporting area of the ball head type can be in contact connection with the foot supporting plate through a ball head ball socket friction pair.

Optionally, the bearing area is a stop table.

Optionally, the stop table is a stop boss, wherein the stop boss is raised relative to the fixing region.

Optionally, the stop boss is annular, wherein the wall thickness of the stop boss is greater than the wall thickness of the strain sensitive area.

Optionally, the wall thickness of the strain sensitive region is 50% to 95% of the wall thickness of the stop boss.

Optionally, the structure of being surveyed is the landing leg, the fixed area passes through the transition piece structure makes the force sensor subassembly with the perpendicular support hydro-cylinder piston body of rod mechanical connection of landing leg, wherein, the transition piece structure is fixed in the perpendicular support hydro-cylinder piston body of rod department of landing leg, the fixed area pass through the fastener with transition piece structure mechanical connection.

Optionally, the size of the gap satisfies the following condition:

wherein u is the size of the gap, F_mFor the rated load of landing leg, A does the locking boss the area of upper surface, k is factor of safety, h is the height of boss, E is the material elastic modulus of force sensor subassembly.

Optionally, the size of the gap ranges from 0.1mm to 1.0 mm.

Optionally, a sealant, preferably a soft sealant, is filled in the gap.

Optionally, each set of strain gauges includes a plurality of strain gauge pairs, and the strain gauge pairs are configured to be installed in a T shape or an inverted T shape, wherein each strain gauge pair in the same set of strain gauges is annularly and symmetrically arranged at the same height.

Optionally, the carrier region, the anchor region, the strain sensitive region, and the support region are integrally formed.

Correspondingly, the embodiment of the utility model provides a still provide an engineering machine tool, including foretell force sensor subassembly.

The embodiment of the utility model provides a atress sensor assembly has following advantage:

(1) in the loading process of the stress sensor assembly, the upper surface of the bearing area in the normal load transfer relation is a load bearing surface, however, the stress sensor assembly body can generate tiny compression elastic deformation, and the fixed area partially bears partial load. The arrangement of the anchor region in clearance fit with the transition piece structure maintains the load carrying region alone and avoids the anchor region from carrying loads in part.

(2) The device can be mechanically connected with a structure to be detected, and can be matched with a strain gauge arranged in a cavity of a strain sensitive area, so that the device can monitor stress in real time;

(3) the method has the advantages of high reliability, high comprehensive precision, good dynamic measurement performance, low delay and the like, can ensure the bearing safety and the protective performance, and has small change on the whole engineering machine and convenient maintenance and replacement when being applied to the engineering machine.

Other features and advantages of embodiments of the present invention will be described in detail in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the embodiments of the invention, but do not constitute a limitation of the embodiments of the invention. In the drawings:

fig. 1 shows a schematic view of an installation of a force sensor assembly as a leg reaction force sensor assembly according to an embodiment of the present invention;

fig. 2 shows a schematic view illustrating the structure and installation of a force sensor assembly as a leg reaction force sensor assembly according to an embodiment of the present invention;

fig. 3(a) shows a plan view of the leg reaction force sensor assembly shown in fig. 2, and fig. 3(b) shows a perspective view of the leg reaction force sensor assembly shown in fig. 2;

FIG. 4 shows a cross-sectional view of the leg reaction force sensor assembly shown in FIG. 2;

FIG. 5 illustrates the blocking effect of the annular groove on the distributed transmission of the foot support plate contact force;

FIG. 6 shows a dimensional schematic of the annular groove;

FIG. 7 shows a schematic diagram of a bridge circuit formed by strain gauges;

FIG. 8 shows a leg reaction load path transfer diagram;

fig. 9 is a schematic view showing the structure and installation of a force sensor assembly as a leg reaction force sensor assembly according to an embodiment of the present invention;

FIGS. 10(a) to 10(c) show a top view, a side view, and a perspective view, respectively, of the force sensor assembly shown in FIG. 9 as a leg reaction force sensor assembly; and

fig. 11 shows a cross-sectional view of the leg reaction force sensor assembly shown in fig. 9.

Detailed Description

The following describes in detail embodiments of the present invention with reference to the accompanying drawings. It is to be understood that the description herein is only intended to illustrate and explain embodiments of the present invention, and is not intended to limit embodiments of the present invention.

It should be noted that, the orientation relationship described in the embodiments of the present invention is described by taking the case where the force sensor assembly is vertically placed (the bearing area is above and the supporting area is below), and the orientation relationship involved may be correspondingly changed when the placing direction of the force sensor assembly is changed. The terms "surround", "annular" and the like mean a closed ring formed in various shapes such as a square, a circle and the like. Additionally, the utility model provides a atress sensor module can also be used for detecting the transverse force except being used for detecting vertical power.

An embodiment of the utility model provides a force sensor subassembly, it can include: the upper surface of the bearing area is used for bearing the load applied by the structure to be tested; a fixed region for mechanical connection with a structure under test, wherein the fixed region is disposed around the load-bearing region; the strain sensitive area is positioned below the fixed area, and one or more groups of strain gauges are arranged on the inner wall of the cavity of the strain sensitive area, wherein each group of strain gauges form a bridge circuit; and a support region below the strain sensitive region for supporting.

The load bearing zone, anchor zone, strain sensitive zone, support zone may each be a separate component, or preferably the load bearing zone, anchor zone, strain sensitive zone, support zone may be integrally formed.

The support region may be provided with an annular groove. The annular groove can block the dispersion of a force transmission path of the sensor assembly, so that the strain of the strain sensitive area is insensitive to the contact force distribution change at the bottom of the supporting area, and the measurement precision is improved. Set up the annular groove, make will the utility model provides a when the atress sensor subassembly measures the landing leg counter-force as landing leg counter-force sensor subassembly, can reduce landing leg counter-force contact surface distribution and change the influence to measuring, improve the measurement accuracy of landing leg counter-force.

The strain sensitive region may be any suitable structure provided with a cavity, and may be, for example, a cylindrical strain sensitive region, preferably a cylindrical strain sensitive region, but is not limited thereto, and may also be, for example, a square cylindrical strain sensitive region or other types of strain sensitive regions.

The support area is preferably of the ball head type. Under the condition that the supporting area is the supporting area, a bottom foot supporting plate can be further arranged, and the supporting area of the ball head type and the bottom foot supporting plate can be in contact connection through a ball head and ball socket pair, so that the supporting effect is achieved. The support areas may also be of a cuboid shape, in which case the footing support plates may not be provided.

The inner side section of the annular groove is in a circular arc shape or other transitional circular arc shapes. The annular groove may be provided in the lower half of the support region. The groove ring of the annular groove can be in a shape of equal height or in a shape of unequal height. The groove height (or average height) is too small to easily form stress concentration on the inner side, the height is too large to reduce the structural strength, and there is a safety risk, and a suitable groove height is 1/10 to 1/2 of the diameter of the support region. Similarly, the annular groove has a neck diameter that is too large and the contact force breaking effect is insignificant, and too small, affecting structural strength, so suitable neck diameters are 1/5 to 9/10 of the diameter of the support zone. In the case of a support zone of the ball-head type, the diameter of the support zone is the diameter of the ball-head type. In the case of a support zone of the cuboid type, the diameter of the support zone is the cuboid transverse width.

The opening of the annular groove may preferably face horizontally to the outside, but the embodiment of the present invention is not limited thereto, and the opening direction of the annular groove may be set to be arbitrary, and the opening direction may face a direction at an arbitrary angle with the horizontal direction, for example, the opening direction may be obliquely upward or obliquely downward. The provision of a horizontally outwardly facing annular groove opening is more advantageous to machine than annular grooves in other directions and such an arrangement minimizes material removal and structural load bearing losses.

The fixation region may mechanically connect the force sensor assembly to the structure under test via a transition piece structure, and the fixation region may mechanically connect to the transition piece structure via a fastener. The fasteners may be, for example, bolts or the like. In an alternative, the fastening region may also be fastened to the transition piece structure by welding. Additionally, it will be appreciated that the use of a transition piece structure may not be required if the structure being measured matches the structure of the force sensor assembly. The fixed area is directly connected with the tested structure mechanically.

The bearing area can be arranged as a stop table, and the stop table has the advantages of resisting horizontal lateral force and avoiding the sliding dislocation of the bearing area. The stop land may be a stop boss or a stop recess land. It will be appreciated that the location of the load bearing zone is not limited to a stop and may be other types of load bearing zones, for example, the middle of the load bearing zone may not have a cavity as the stop.

The stop abutment may preferably be a stop boss, since the upper surface of the stop boss is located at a greater distance from the strain gauge on which the strain sensitive area is located, thus providing greater measurement accuracy. The stop boss may be annular and the wall thickness of the stop boss may be arranged to be greater than the wall thickness of the strain sensitive region. The transition between the stop lug and the strain sensitive region may have a thickness variation such that the wall thickness of the stop lug is greater than the wall thickness of the barrel-type strain sensitive region. This may be advantageous to reduce the strain effect of the detent boss contact force distribution on the barrel strain sensitive area. This is because the contact surface of the stopper boss is increased, so that the contact stress is reduced; and the thickness of the opening of the stop boss is increased, the structural rigidity is increased, and the contact stress distribution is not easily influenced by deformation. The beneficial effect who sets up like this is that the distribution of strain of barrel-type strain sensitive area is very even, is favorable to eliminating the precision influence that foil gage process error brought for measurement accuracy is very high.

In order to form the strain sensitive region required by the strain gauge, while making the stress distribution of the sensing region more uniform, and considering the structural strength safety, the wall thickness of the strain sensitive region is preferably reduced to 50% to 95% of the wall thickness of the stop boss.

The fixation section and transition piece structure may be configured to be a tight fit or a clearance fit, preferably both. In the loading process of the stress sensor assembly, the upper surface of the bearing area in the normal load transfer relation is a load bearing surface, however, the stress sensor assembly body can generate tiny compression elastic deformation, and the fixed area partially bears partial load. In order to keep only the bearing region carrying the load and to avoid that the fixing region carries the load partially, at least a part of the upper surface of the fixing region may be arranged to be clearance-fitted with the transition piece structure, i.e. at least a part of the gap may be arranged between the fixing region and the connection face of the transition piece structure. For example, it may be particularly provided that a portion of the upper surface of the fixing zone is in close contact with the transition piece structure and another portion is in clearance fit with the transition piece structure. For example, one half of the upper surface of the fixation section may be provided in intimate contact with the transition piece structure and the other half of the upper surface may be provided in clearance fit with the transition piece structure. Alternatively, the upper surfaces of the fixation areas may all be provided in clearance fit with the transition piece structure.

A suitable gap size u (also referred to as height) is required to prevent the portion of the clearance fit from taking part of the load due to the compressive elastic deformation. The size u (which may be referred to as height) of the gap is set to satisfy the requirement of equation 1 below:

wherein, F_mFor the rated load of the supporting leg, A is the area of the upper surface of the stop boss (namely the area of the load acting surface), h is the height of the boss, E is the elastic modulus of the material of the stress sensor assembly, and k is a safety coefficient and is a known value.

The size u of the gap must have sufficient redundancy design in consideration of machining errors, but the excessive gap brings requirements on sealing, safety, protection and the like, so the comprehensive consideration of the surface gap u is preferably in the range of 0.1mm to 1.0 mm. It should be noted that the size of the gap according to the embodiment of the present invention refers to the size of the gap when the load sensor assembly is not loaded.

The gap may be filled with a sealant, which will not be described herein. May be used to seal dust or the like from outside the sensor assembly. The sealant is preferably a soft sealant, such as a weatherable soft sealant. Because the elastic modulus difference of the metal and the soft sealant is very large, the force transmitted by the sealant can be ignored, and the detection precision is not influenced.

(1) the annular groove is formed in the supporting area, so that the force transmission path of the sensor assembly can be blocked from being dispersed, the strain of the strain sensitive area is insensitive to the contact force distribution change at the bottom of the supporting area, and the measurement precision is improved;

The utility model provides a force sensor subassembly can be the counter-force that is used for measuring any structure of being surveyed, perhaps can be used for measuring horizontal yawing force etc. (under the condition of force sensor subassembly slope). Alternatively, the force sensor assembly may be used as a leg reaction force sensor assembly to measure leg reaction forces.

In the related art, a method for detecting the magnitude of the counterforce of the support leg by the engineering machine is generally realized by detecting the oil pressure of the support leg oil cylinder, but the method has the following defects: (1) an oil pressure sensor needs to be arranged in the oil cylinder for detecting the oil pressure, so that the risk of oil leakage is increased; (2) due to the factors of friction, lateral load, pressure abandoning and the like, the oil pressure thrust and the supporting force are possibly greatly different, so that the measurement precision is very low, and the maximum error is more than 15%; (3) the oil pressure measurement mode is that the landing leg load is transmitted to the pressure sensor through hydraulic oil, is an indirect measurement of the reaction force, has serious hysteresis of signal, and the maximum hysteresis is more than 5 s. Will the utility model provides a landing leg counter-force is measured as landing leg counter-force sensor subassembly to the force sensor subassembly, can avoid above-mentioned defect.

When the sensor assembly is applied as a supporting leg reaction force sensor assembly, the fixed area can be mechanically connected with a vertical oil cylinder piston rod body of a supporting leg through a transition connecting piece structure, wherein the transition connecting piece structure is fixed at the vertical supporting oil cylinder piston rod body of the supporting leg.

The force sensor assembly of the present invention will be exemplified as a leg reaction force sensor assembly by way of example. In each embodiment, the bearing region is a movable boss, the strain sensitive region is a cylindrical strain sensitive region, and the support region is a ball-head support region, i.e., the force sensor assembly is exemplified by using the preferred embodiment of the bearing region, the strain sensitive region, and the support region. It will be appreciated that in other embodiments, the implementation of the load bearing, strain sensitive, and support regions may be a combination of any of these alternative implementations. In the embodiments described below, the force sensor assembly is also referred to as a leg reaction force sensor assembly.

Fig. 1 shows an installation diagram of a force sensor assembly as a leg reaction force sensor assembly according to an embodiment of the present invention. As shown in fig. 1, the leg reaction force sensor assembly 3 can be mechanically connected to the piston rod body of the vertical support cylinder 2 of the leg and installed below the leg beam of the construction machine. The leg reaction force signals detected by the leg reaction force sensor assembly 3 can be transmitted to the main controller by wire (e.g. by cable) or wirelessly (e.g. by radio), and the main controller derives further operation instructions by integrating the leg reaction force signals of a plurality of legs, or calculates required information such as the total weight, the position of the center of gravity, the safety state, etc.

The embodiment of the utility model provides a first embodiment of landing leg reaction force sensor subassembly is shown in fig. 2 to 4. As shown in fig. 2, the leg reaction force sensor assembly 3.2b may be mechanically connected to the vertical support cylinder piston rod body 2.1 (a portion of which is shown in fig. 2) of the leg by a transition piece structure 3.1 b. The transition piece structure 3.1b may be integrally connected to the vertical support cylinder ram body 2.1, for example, by a filler weld process, the weld location being shown as b-1. The transition piece structure 3.1b may be cylindrical to match the shape of the vertical support cylinder ram body 2.1, and the overall width of the transition piece structure 3.1b may be slightly greater than the diameter of the vertical support cylinder ram body 2.1 or both may be substantially the same. The bottom of the transition piece structure 3.1a may be hollowed out in a portion, and the diameter of the hollowed out portion may be the same as the diameter of the stop boss, respectively, to accommodate the stop boss.

The fixing area of the leg reaction sensor assembly may be arranged as a ring, the diameter of which may be substantially the same as the diameter of the transition piece structure 3.1b, in the alternative, the fixing area may also be arranged as a square, etc. In this embodiment, the fixed area is an annular area, and the fixed area is referred to as an annular area in the detailed description. The annular region may be mechanically connected to the transition piece structure 3.1b by fasteners. The fastener may be, for example, bolt b-2. As shown in fig. 3(a) to 3(b), the annular region may be provided with a plurality of bolt holes, which may be evenly distributed. The transition piece structure 3.1b is provided with the same number of bolt holes to achieve a mechanical connection of the two by means of bolts b-2.

The annular region upper surface b-3 is clearance fit with the transition piece structure 3.1b, preferably in the range of 0.1mm to 1.0mm, or may be determined according to equation (1). The gap may be filled with, for example, a weather resistant soft sealant.

The upper surface b-4 of the stop boss is in intimate contact with the transition piece structure 3.1 b. The upper surface b-4 of the stop boss can bear the load of the support leg during operation. The stop boss may be an annular stop boss.

The structure of the support region may be a portion of a spherical structure or substantially the entire spherical structure. As shown in fig. 2, the overall width of the support region may be greater than that of the cylinder-type strain sensitive region and less than that of the annular region. The support area can be in contact connection with the foot support plate 4b through a ball-and-socket friction pair b-5. The surface portion of the support area in contact with the foot support plate 4b is arcuate. When the supporting leg is retracted, the supporting base of the foot can be hung at the contraction part of the supporting leg reaction force sensor assembly through structures such as an upper cover plate or a locking pin.

As shown in fig. 4, in this embodiment, the leg reaction force sensor assembly includes: a stop boss 3.2b-1, an annular zone 3.2b-2, the annular zone comprising a plurality of bolt holes, a cylindrical strain sensitive zone 3.2b-3 and a support zone 3.2 b-4. N1 in fig. 4 represents the applied load (i.e., the load carried by the upper surface of the stopper boss), and the broken line represents the load path in the leg reaction force sensor assembly, and F represents the resultant contact load force. The counterforce of the support leg is the vertical component of the resultant force of the contact load. A schematic diagram of the positive pressure force of the leg reaction force sensor assembly is shown in fig. 4. The stop boss 3.2b-1, the annular zone 3.2b-2, the barrel-type strain sensitive zone 3.2b-3 and the support zone 3.2b-4 may be integrally formed.

The wall thickness of the stop boss 3.2b-1 may be set larger than the wall thickness of the barrel-type strain sensitive area 3.2 b-3. The stop boss 3.2b-1 may have a thickness variation at the transition 3.2b-6 to the barrel-type strain sensitive area 3.2b-3 such that the wall thickness of the stop boss 3.2b-1 is greater than the wall thickness of the barrel-type strain sensitive area 3.2 b-3. This may be advantageous to reduce the strain effect of the detent boss contact force distribution on the barrel strain sensitive area. This is because the contact surface of the stopper boss is increased, so that the contact stress is reduced; and the thickness of the opening of the stop boss is increased, the structural rigidity is increased, and the contact stress distribution is not easily influenced by deformation. The beneficial effect who sets up like this is that the distribution of strain of barrel-type strain sensitive area is very even, is favorable to eliminating the precision influence that foil gage process error brought for measurement accuracy is very high.

In order to form the strain sensitive region required for the strain gauge, while making the stress distribution of the sensing region more uniform, and considering the structural strength safety, the wall thickness of the barrel-type strain sensitive region is preferably reduced to 50% to 95% of the wall thickness of the stopper boss.

The embodiment of the utility model provides a also have certain restriction to the bolt pretightning force of using with transition piece structure mechanical connection. As can be seen from the load path shown by the dotted line in fig. 4, the bolt pretightening force transmission path does not pass through the cylindrical strain sensitive area and is far away from the installation position of the strain patch, so that the influence on the measurement result of the support leg reaction force sensor assembly is small. However, when the pretightening force of the bolt is too large, the cylindrical structure can be radially deformed, and the transverse strain can be deviated. Therefore, when the supporting leg reaction force sensor assembly is used, the pretightening force of the bolt needs to be adjusted within a reasonable range, and the stability of initial output is ensured. Preferably, the bolt pretension force is reasonably in the range of 10 N.m to 80 N.m.

The support areas 3.2b-4 may be provided with annular grooves 3.2b-7 which may reduce the strain effect of variations in the contact force distribution of the support areas on the cartridge type strain sensitive areas. As can be seen from the load transmission path shown by the dotted line in fig. 4, the load is concentrated at the bottom portion of the foot supporting plate, thereby blocking the dispersed transmission of the contact force of the foot supporting plate, so that the cylinder type strain sensitive region strain is insensitive to the variation of the contact force distribution. The blocking effect of the annular groove is shown in fig. 5. The transmission path of the leg reaction force in the leg reaction force sensor assembly is shown by the dark area in the figure.

As shown in fig. 6, the inside cross-section of the annular groove is in the shape of a circular arc or other transitional circular arc. The annular groove may be provided in the lower half of the support region. The groove ring of the annular groove may be of the same height as shown or of different heights. The groove height is too small, stress concentration on the inner side is easy to form, the height is too large, the structural strength can be reduced, and safety risk exists, and a proper groove height dimension H is 1/10D-1/2D, wherein D is the diameter of the supporting area. Similarly, the necking diameter of the annular groove is too large, the contact force breaking effect is insignificant, and the necking diameter is too small, affecting the structural strength, so that suitable necking diameters D are 1/5D to 9/10D, where D is the diameter of the support zone.

The design of the annular groove has the beneficial effects that when a large load is applied, the contact relation is severe, or the offset load is applied, the annular groove enables the strain of the cylindrical strain sensitive area to be insensitive to the contact force distribution change of the bottom of the ball head, so that high measurement precision is formed.

One or more groups of strain gauges 3.2b-5 can be stuck to the appropriate height position of the inner wall of the cavity of the cylinder type strain sensitive area 3.2b-3, and each group of strain gauges can comprise 4 strain gauge pairs which are annularly and symmetrically arranged. The strain gage pair may include transversely and longitudinally arranged strain gages arranged in the same position to form a T-shape or an inverted T-shape. Each set of strain gages may form a bridge circuit. The proper height is the place where the strain of the stress analysis is more uniform. The utility model discloses in arbitrary embodiment, the foil gage is only preferred mode to arranging with T style of calligraphy or the style of calligraphy of falling T, and is optional, and the foil gage is to also arranging with L type or the type of falling L, or any other types.

Fig. 7 shows a schematic diagram of a bridge circuit formed by strain gauges. In fig. 7, Rv1 and Rh1, Rv2 and Rh2 … … are strain gauge pairs, respectively, where Rv1, Rv2 … … denote vertically arranged strain gauges, and Rh1, Rh2 … … denote laterally arranged strain gauges. Ui is the input voltage of the bridge circuit, and Uo is the output voltage. The side of the annular area can be provided with a cable hole, and a cable connected with the output of the bridge circuit extends out of the supporting leg reaction force sensor assembly through the cable hole. The output of the bridge circuit may also be transmitted wirelessly.

In this embodiment, one set of strain gauges is only used for example, and multiple sets of strain gauges may be disposed in the cavity of the barrel-type strain sensitive area. Different strain gauge groups can be arranged at different heights or the same height, and each strain gauge pair of the same strain gauge group is arranged at the same height.

Fig. 8 shows a leg reaction force load path transfer diagram. As shown in fig. 8, the leg reaction force load path is: the ground is greater than a footing support plate, a landing leg counter-force sensor component, a vertical oil cylinder, a combined landing leg beam and an engineering machine frame, wherein the ground is in contact with the footing support plate, the footing support plate is in contact connection with the landing leg counter-force sensor component through a ball head and ball socket pair, the landing leg counter-force sensor component is welded with the vertical oil cylinder through a transition connecting piece structure, the vertical oil cylinder is mechanically connected with the combined landing leg beam, and the combined landing leg beam and the engineering machine frame are stressed through a sliding block. Landing leg reaction force sensor subassembly direct embedding is in landing leg reaction force transmission route, therefore does not have other transmission routes to share the landing leg reaction and leads to landing leg reaction force sensor subassembly to measure the deviation, and the dynamometry direction of landing leg reaction force sensor subassembly is the vertical atress direction of perpendicular hydro-cylinder to structure itself is movable bulb structure, can effectively reduce the influence of side load to measurement accuracy.

The second embodiment of the leg reaction force sensor assembly according to the embodiment of the present invention is shown in fig. 9 to 11. As shown in fig. 9, the leg reaction force sensor assembly 3.2a may be mechanically connected to the vertical support cylinder piston rod body 2.1 (a portion of which is shown in fig. 2) of the leg by a transition piece structure 3.1 a. The transition piece structure 3.1a may be integrally connected to the vertical support cylinder ram body 2.1, for example, by a filler weld process, the weld location being shown as a-1. The transition piece formation 3.1a may be cylindrical to match the shape of the vertical support cylinder ram body 2.1 and may be substantially the same diameter. The bottom of the transition piece structure 3.1a may be hollowed out in a portion, and the diameter of the hollowed out portion may be the same as the diameter of the stop boss, respectively, to accommodate the stop boss.

The fixing area of the leg reaction sensor assembly may be arranged as a ring, the diameter of which may be substantially the same as the diameter of the transition piece structure 3.1a, in the alternative, the fixing area may also be arranged as a square, etc. In this embodiment, the fixed area is an annular area, and the fixed area is referred to as an annular area in the detailed description. The annular region may be mechanically connected to the transition piece structure 3.1a by fasteners. The fastener may be, for example, bolt a-2. As shown in fig. 10(a) to 10(c), the annular region may be provided with a plurality of bolt holes, which may be evenly distributed. The transition piece structure 3.1a is provided with the same number of bolt holes to achieve a mechanical connection of the two by means of bolts a-2.

One part of the upper surface of the annular region is in close contact with the transition piece structure 3.1a, and the other part a-3 is in clearance fit with the transition piece structure 3.1a, and the clearance can be filled with a weather-resistant soft sealant for example. For example, one half of the upper surface of the annular region may be provided in intimate contact with the transition piece structure 3.1a and the other half of the upper surface may be provided in clearance fit with the transition piece structure 3.1 a.

The upper surface a-4 of the stop boss is in intimate contact with the transition piece structure 3.1 a. The upper surface a-4 of the stop boss can bear the load of the support leg during operation. The stop boss may be an annular stop boss. In this embodiment, the stop boss, the annular region and the barrel-type strain sensitive region have cavities of substantially the same diameter. The diameter of the cavity of the cylinder type strain sensitive area can also be larger than the diameter of the cavity of the stop boss and the annular area, so that a better strain sensitive effect can be formed in the cylinder type strain sensitive area.

The structure of the support region may be a portion of a spherical structure or substantially the entire spherical structure. As shown in fig. 3(b), the overall width of the support region may be greater than that of the cylinder-type strain sensitive region and less than that of the annular region. The support area can be in contact connection with the foot support plate 4a via a ball-and-socket friction pair a-5. The surface portion of the support area in contact with the foot support plate 4a is arcuate. When the supporting leg is retracted, the supporting base of the foot can be hung at the contraction part of the supporting leg reaction force sensor assembly through structures such as an upper cover plate or a locking pin.

As shown in fig. 4, in this embodiment, the leg reaction force sensor assembly includes: a stop boss 3.2a-1, an annular zone 3.2a-2 containing a plurality of bolt holes, a cylindrical strain sensitive zone 3.2a-3 and a support zone 3.2 a-4. N1 in fig. 4 represents the applied load (i.e., the load carried by the upper surface of the stopper boss), and the broken line represents the load path in the leg reaction force sensor assembly, and F represents the resultant contact load force. The counterforce of the support leg is the vertical component of the resultant force of the contact load. A schematic diagram of the positive pressure force of the leg reaction force sensor assembly is shown in fig. 4. The stop boss 3.2a-1, the annular zone 3.2a-2, the barrel-type strain sensitive zone 3.2a-3 and the support zone 3.2a-4 may be integrally formed. The landing leg reaction force sensor assembly provided by the embodiment has the advantages of simple and compact structure, high reliability, high unbalance loading resistance, high safety and the like.

The wall thickness of the stop boss 3.2a-1 may be set substantially equal to the wall thickness of the barrel-type strain sensitive area 3.2 a-3. Alternatively, the wall thickness of the stop boss 3.2a-1 may be made greater than the wall thickness of the barrel-type strain sensitive area 3.2a-3, similar to the first embodiment, to reduce the effect of the stop boss contact force distribution on the barrel-type strain sensitive area strain.

One or more groups of strain gauges 3.2a-5 can be stuck on the inner wall of the cavity of the cylinder type strain sensitive area 3.2a-3 at proper height, and each group of strain gauges can comprise 4 strain gauge pairs which are annularly and symmetrically arranged. The strain gage pair may include transversely and longitudinally arranged strain gages arranged in the same position to form a T-shape or an inverted T-shape. Each set of strain gages may form a bridge circuit. The proper height is the place where the strain of the stress analysis is more uniform. The utility model discloses in arbitrary embodiment, the foil gage is only preferred mode to arranging with T style of calligraphy or the style of calligraphy of falling T, and is optional, and the foil gage is to also arranging with L type or the type of falling L, or any other types.

In this embodiment, the bridge circuit formed by the strain gauge is the same as the bridge circuit shown in fig. 7, and will not be described again here. In addition, similarly, multiple groups of strain gauges can be arranged in the cavity of the cylinder type strain sensitive area. Different strain gauge groups can be arranged at different heights or the same height, and each strain gauge pair of the same strain gauge group is arranged at the same height.

In this embodiment, the restriction of the size of clearance in the clearance fit, the restriction of bolt pretightning force, landing leg counter-force load path transmission etc. all with the embodiment of the utility model provides a landing leg counter-force sensor subassembly's first embodiment is the same, will not be repeated here.

The embodiment of the utility model provides a following advantage has when the atress sensor assembly is as landing leg reaction force sensor subassembly:

(1) the device is less influenced by installation and is insensitive to a contact boundary, particularly, the arranged annular groove can block the force transmission path dispersion of the sensor assembly, so that the strain of the cylindrical strain sensitive area is insensitive to the contact force distribution change at the bottom of the supporting area, the influence of the distribution change of the counterforce contact surface of the supporting leg on measurement is reduced, and the measurement precision is improved.

(2) When the supporting legs deflect, the connecting bolt is enabled to be hardly subjected to shearing force due to the design of the stop boss, the deflecting load is borne by the contact force of the front face and the side face of the boss, the fracture risk of the bolt is reduced, and the anti-deflecting load safety is high.

(3) The transition connecting piece structure and the oil cylinder piston rod body are welded into a whole, the supporting leg reaction force sensor assembly is disassembled and assembled only by fastening or loosening the connecting bolt, and the initial output (zero deviation) is insensitive to the variation of the pretightening force of the bolt because the bolt installation position is not between the supporting leg reaction force action position and the strain measurement area, so that the installation and the maintenance are convenient.

(4) On the other hand, the strategy of the annular groove in the supporting zone can reduce errors caused by uncertainty of contact points in the supporting zone structurally, and improves the measurement accuracy of counter force of the supporting leg under the conditions of lateral loads such as deformation of the supporting leg, inclination of a supporting plate of the bottom leg, oblique-pulling and oblique-hanging and the like.

Correspondingly, the embodiment of the utility model provides a still provide an engineering machine tool, this engineering machine tool can include according to the utility model discloses arbitrary embodiment the force sensor subassembly.

It is to be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in the process, method, article, or apparatus that comprises the element.

The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A force sensor assembly, comprising:

the upper surface of the bearing area is used for bearing the load applied by the structure to be tested;

a fixed region for mechanical connection with a structure under test, wherein the fixed region is disposed around the load-bearing region;

the strain sensitive area is positioned below the fixed area and is provided with a cavity, and one or more groups of strain gauges are arranged on the inner wall of the cavity, wherein each group of strain gauges form a bridge circuit; and

a support region under the strain sensitive region for supporting,

wherein the fixation region mechanically connects the force sensor assembly to the structure under test via a transition piece structure, and at least a portion of the fixation region upper surface is clearance fit with the transition piece structure.

2. The force sensor assembly of claim 1, wherein the support region is provided with an annular groove.

3. The force sensor assembly of claim 2 wherein the annular groove has an inner cross-section in the shape of a circular arc, a height of the annular groove being 1/10 to 1/2 of the diameter of the support region, and a necked-down diameter of the annular groove being 1/5 to 9/10 of the diameter of the support region.

4. The force sensor assembly of claim 3, wherein the opening of the annular groove faces horizontally outward.

5. The force sensor assembly of claim 1,

the strain sensitive area is a cylindrical strain sensitive area; and/or

The supporting area is of a ball head type, and the supporting area of the ball head type can be in contact connection with the bottom foot supporting plate through a ball head ball socket friction pair.

6. The force sensor assembly of claim 5, wherein the strain sensitive region is a cylindrical strain sensitive region.

7. The force sensor assembly of claim 1, wherein the bearing region is a stop.

8. The force sensor assembly of claim 7, wherein the stop ledge is a stop boss, wherein the stop boss is raised above the fixation area.

9. The force sensor assembly of claim 8, wherein the stop boss is annular, wherein a wall thickness of the stop boss is greater than a wall thickness of the strain sensitive area.

10. The force sensor assembly of claim 9, wherein the wall thickness of the strain sensitive region is 50% to 95% of the wall thickness of the stop boss.

11. The force sensor assembly of claim 8 or 9, wherein the structure under test is a leg, the attachment region mechanically connects the force sensor assembly to a vertical support cylinder ram body of the leg via the transition piece structure,

the transition connecting piece structure is fixed at the position of a vertical supporting oil cylinder piston rod body of the supporting leg, and the fixing area is mechanically connected with the transition connecting piece structure through a fastening piece.

12. The force sensor assembly of claim 11, wherein the size of the gap satisfies the following condition:

13. The force sensor assembly of claim 11, wherein the gap has a size in a range of 0.1mm to 1.0 mm.

14. The force sensor assembly of claim 1, wherein the gap is filled with a sealant.

15. The force sensor assembly of claim 14, wherein the sealant is a flexible sealant.

16. The force sensor assembly of claim 1, wherein each set of strain gages includes a plurality of strain gage pairs configured to be mounted in a T-shape or inverted T-shape,

and all the strain gauge pairs in the same group of strain gauges are circularly and symmetrically arranged at the same height.

17. The force sensor assembly of claim 1, wherein the load-bearing zone, the anchor zone, the strain-sensitive zone, and the support zone are integrally formed.

18. A work machine comprising a force sensor assembly as claimed in any one of claims 1 to 17.