CN106556488A - A kind of strain-type six-dimension force sensor - Google Patents

Abstract

The invention discloses a strain type six-dimensional force sensor, which comprises a bottom cover, a base, a circuit board, an elastic body and a top cover, the bottom cover is connected with the bottom surface of the base, the circuit board is located on the base Inside the seat, the four elastic bodies are evenly distributed in the base, the outer end of the sensitive element of the elastic body is connected with the base, the inner end of the sensitive element of the elastic body is connected with the top cover, and the The top cover is supported on the base by elastic body. The strain-type six-dimensional force sensor of the present invention can well eliminate inter-dimensional coupling due to the use of multiple elastic bodies and a reasonable bridge design of strain gauges. Through the elastic body with a special structure, the strain-type six-dimensional force sensor It has high stiffness and good sensitivity.

Description

A strain gauge six-dimensional force sensor

technical field

The invention belongs to the technical field of sensors, and relates to a resistance strain sensor capable of simultaneously detecting three-dimensional force and three-dimensional moment.

Background technique

The six-dimensional force/torque sensor is a newly developed sensor in the force sensor, which can convert multi-dimensional force/torque signals into electrical signals at the same time, and can be used to monitor force and torque with changing directions and sizes. With the development of aerospace, modern robots and other fields, there are more and more applications of six-dimensional force sensors.

In the strain gauge multi-dimensional force sensor, the elastomer structure is the main factor affecting the performance of the sensor. According to the structural form of the elastomer, the elastomer can be divided into a one-piece structure and a composite structure. A monolithic structure is generally a single geometric shape, with elastic strain distributed across different regions of the elastomer surface. The composite structure is mostly a multi-plane combined structure, and the elastic strain is distributed in different regions on different surfaces of the elastomer.

According to the acquisition method of each independent component in the force vector, the elastic body structure of the multidimensional force sensor can be divided into two types: direct output type sensor (uncoupled type) and indirect output type sensor (coupled type). The elastic body of the direct output sensor has no coupling effect, and the force vector can be obtained directly from the output of the sensor and the structural constant. The structure of this elastomer is simple, but the volume is large, and the non-integral component will produce a large hysteresis. The elastic body of the indirect output sensor is small in size, light in weight and small in hysteresis, but the data processing is more complicated.

At present, judging from the six-dimensional force sensor put into use, the structure basically adopts an indirect output composite structure. The problems in the design of this structure are mainly manifested in the contradiction between sensitivity and stiffness, and the coupling between dimensions.

Contents of the invention

In view of the shortcomings of the six-dimensional force sensor in the prior art, such as inter-dimensional coupling and stiffness-sensitivity contradictions, the purpose of the present invention is to provide a strain-type six-dimensional force sensor that can structurally solve the problem of inter-dimensional coupling and ensure stiffness and sensitivity at the same time.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A strain-type six-dimensional force sensor, comprising a bottom cover, a base, a circuit board, an elastic body and a top cover, the bottom cover is connected to the bottom surface of the base, the circuit board is located inside the base, four The two elastic bodies are evenly distributed in the base, the outer end of the sensitive element of the elastic body is connected with the base, the inner end of the sensitive element of the elastic body is connected with the top cover, and the top cover is elastically The body is supported on the base.

The base includes a cylindrical base and a base boss that is located on the plane of the cylindrical base and extends upwards. The outer edge of the base is provided with several U-shaped grooves, and the outer edge of the base is provided with several The base groove is used for easy handling and eyebolts are set on the base groove, the outer wall of the base boss is provided with socket holes for installing sockets, and the inner wall of the base boss is provided with four evenly distributed The elastic body installation groove is connected to the end surface of the outer end of the sensitive element of the elastic body, and the circuit board installation plane for installing the circuit board is arranged in the boss of the base.

The outer diameter of the circuit board mounting plane is the same as the outer diameter of the circuit board.

The boss of the base is circular.

The plane of the elastic body installation groove is provided with a first positioning pin hole for positioning the position of the elastic body on the base, a first through hole for connecting the outer end of the sensitive element and the base, and the four first The through holes are distributed in a rectangular shape, corresponding to the first screw holes on the outer end of the sensitive element, and the first positioning pin holes are located at the centers of the four first through holes.

The elastic body includes a sensitive element, a strain gauge, a strain gauge terminal, and a protective cover for the sensitive element. The four strain gauges are evenly distributed on the sensitive area of the sensitive element, and the two strain gauge terminals are located on the sensitive element step of the sensitive element. On the plane, the two sensitive element protective covers are located outside the sensitive area, the two sensitive element protective covers are fastened to each other, and the fastened sensitive element protective covers are fixed on the outer end of the sensitive element by screws , leaving a gap between the inner side of the sensitive element.

The sensitive element is in the shape of a dumbbell, and the outer end of the sensitive element is provided with a second through hole for fixing the protective cover of the sensitive element, a second positioning pin hole for positioning the elastic body on the base, and a second positioning pin hole for connecting the outer end of the sensitive element and the first screw hole of the base, and the inner end of the sensitive element is provided with a second screw hole for connecting the inner end of the sensitive element and the top cover.

The second positioning pin hole is located at the center of the outer end surface of the sensitive element, the two second through holes are symmetrically distributed on both sides of the second positioning pin hole, and the four first screw holes are arranged in the circumferential direction. The four second screw holes are evenly distributed on the inner end of the sensitive element in the circumferential direction, corresponding to the third through holes on the installation plane of the elastic body.

The shape of the strain gauge terminal is a semi-circular ring, two strain gauge terminals form a circular ring and are located on the step of the sensitive element, and the leads of the strain gauge are welded on the pads on the strain gauge terminal.

The shape of the sensitive element protective cover is semi-circular, and a wire passing hole is arranged on the sensitive element protective cover.

The top cover includes a cylindrical structure and a cylindrical boss located at the center of the bottom surface of the cylindrical structure and extending downwards.

There are several third screw holes on the upper plane of the cylindrical structure, which are used to install and fix the objects to be monitored. With the center of the cylindrical structure as the center, several circles of evenly distributed shallow grooves are provided for improving The installation accuracy of the object to be monitored.

Cylindrical structure grooves are uniformly distributed around the cylindrical boss on the bottom surface of the cylindrical structure.

The bottom surface of the cylindrical boss is provided with evenly distributed cylindrical boss grooves, and the outer wall of the cylindrical boss is provided with four evenly distributed elastic body installation planes, and the elastic body installation plane is in contact with the The end surface of the inner end of the sensitive element is connected, and four third through holes are uniformly distributed on the elastic mounting plane and correspond to the four second screw holes on the inner end of the sensitive element.

Owing to adopting above-mentioned technical scheme, the present invention has following advantage and beneficial effect:

The strain-type six-dimensional force sensor of the present invention can well eliminate inter-dimensional coupling due to the use of multiple elastic bodies and a reasonable bridge design of strain gauges. Through the elastic body with a special structure, the strain-type six-dimensional force sensor It has high stiffness and good sensitivity.

Description of drawings

FIG. 1 is a schematic diagram of the overall structure of a strain gauge six-dimensional force sensor according to an embodiment of the present invention.

Fig. 2 is an exploded view of a strain gauge six-dimensional force sensor according to an embodiment of the present invention.

Figure 3 is an exploded view of the elastomer.

Figure 4 is a front view of the sensitive element.

Fig. 5 is a structural schematic view looking up at the top cover at a certain angle.

Fig. 6 is a schematic diagram of the structure of the base.

Among them: 1 is the bottom cover, 2 is the base, 211 is the base, 212 is the boss of the base, 213 is the U-shaped groove, 214 is the groove of the base, 215 is the socket hole, 216 is the elastic body installation groove, 217 is the circuit board Mounting plane, 218 is the first positioning pin hole, 219 is the first through hole, 3 is the circuit board, 4 is the elastic body, 411 is the sensitive element, 412 is the strain gauge, 413 is the strain gauge terminal, 414 is the protective cover of the sensitive element , 4111 is the outer end of the sensitive element, 4112 is the inner end of the sensitive element, 4113 is the sensitive area, 4114 is the step of the sensitive element, 4115 is the second positioning pin hole, 4116 is the second through hole, 4117 is the first screw hole, 4118 is The second screw hole, 4141 is the wire hole, 5 is the top cover, 51 is the third screw hole, 52 is a shallow groove, 53 is a cylindrical structure, 54 is a cylindrical boss, 55 is a cylindrical structure groove, 56 It is a cylindrical boss groove, 57 elastic body mounting planes, and 58 is the third through hole.

detailed description

The present invention will be described in further detail below in conjunction with the embodiments shown in the accompanying drawings.

Example 1

A strain-type six-dimensional force sensor, as shown in Figure 1 and Figure 2, Figure 1 is a schematic diagram of the overall structure of the strain-type six-dimensional force sensor of the embodiment of the present invention; Figure 2 is a schematic diagram of the strain-type six-dimensional force sensor of the embodiment of the present invention An exploded view, including a bottom cover 1, a base 2, a circuit board 3, an elastic body 4 and a top cover 5, the bottom cover 1 is connected to the bottom surface of the base 2, and the circuit board 3 is located on the base 2 Inside, the four elastic bodies 4 are evenly distributed in the base 2, the outer end 4111 of the sensitive element of the elastic body 4 is connected to the base 2, and the inner end 4112 of the sensitive element of the elastic body 4 is connected to the The top cover 5 is connected, and the top cover 5 is supported on the base 2 through the elastic body 4 .

The base 2 includes a cylindrical base 211 and a base boss 212 that is arranged on the plane of the cylindrical base 211 and extends upwards. The outer edge of the base 211 is provided with several U-shaped grooves 213. Through the T The strain-type six-dimensional force sensor is fixed on the T-slot platform by the groove bolt. When the strain-type six-dimensional force sensor is used, the strain-type six-dimensional force sensor is fixed on the T-slot platform with the T-slot bolt. Installed on the top cover 5 through screw connection; the outside of the base 211 is provided with a number of base grooves 214 for easy handling and eyebolts are arranged on the base grooves 214, and the eyebolts are used to lift the entire strain-type six-dimensional force For the sensor, the outer wall of the base boss 212 is provided with a socket hole 215 for installing a socket, and the inner wall of the base boss 212 is provided with four evenly distributed elastic body installation grooves 216, and the elastic body installation grooves The groove 216 is connected to the end surface of the outer end 4111 of the sensitive element of the elastic body 4 , and a circuit board mounting plane 217 for mounting the circuit board 3 is provided in the base boss 212 . The structure of the base 2 is shown in FIG. 6 , which is a schematic structural view of the base.

The outer diameter of the circuit board installation plane 217 is the same as the outer diameter of the circuit board 3 .

The base boss 212 is circular.

The plane of the elastic body mounting groove 216 is provided with a first positioning pin hole 218 for positioning the position of the elastic body 4 on the base 2, and a first through hole 219 for connecting the outer end 4111 of the sensitive element with the base 2 , the four first through holes 219 are distributed in a rectangular shape, corresponding to the first screw hole 4117 on the outer end 4111 of the sensitive element, and the first positioning pin hole 218 is located at the center of the four first through holes 219 .

The elastic body 4 includes a sensitive element 411, a strain gauge 412, a strain gauge terminal 413, and a protective cover 414 for the sensitive element. The four strain gauges 412 are evenly distributed on the sensitive area 4113 of the sensitive element 411, and the two strain gauges The terminal 413 is located on the plane of the sensitive element step 4114 of the sensitive element 411, and the two sensitive element protective covers 414 are located outside the sensitive area 4113, and the two sensitive element protective covers 414 are fastened to each other, and are fastened together by screws. The sensitive element protective cover 414 is fixed on the outer end 4111 of the sensitive element, and there is a certain gap between the inner end 4112 of the sensitive element. In order to protect the strain gauge 412 from dust, impurities and the like. There are four elastic bodies 4 on the strain-type six-dimensional force sensor, and the four elastic bodies 4 are evenly distributed on the base 2 and the top cover 5 along the circumferential direction, and cooperate with each other to achieve the purpose of monitoring force/moment in six directions . The structure of the elastic body is shown in Figure 3, and Figure 3 is an exploded view of the elastic body.

The sensitive element 411 is in the shape of a dumbbell, and the outer end 4111 of the sensitive element is provided with a second through hole 4116 for fixing the protective cover 414 of the sensitive element, and a second positioning pin hole 4115 for positioning the position of the elastic body 4 on the base 2, The first screw hole 4117 is used to connect the outer end 4111 of the sensitive element with the base 2 , and the inner end 4112 of the sensitive element is provided with a second screw hole 4118 for connecting the inner end 4112 of the sensitive element with the top cover 5 .

The second positioning pin hole 4115 is located at the center of the end surface of the outer end 4111 of the sensitive element, the two second through holes 4116 are symmetrically distributed on both sides of the second positioning pin hole 4115, and the four first screw holes The holes 4117 are evenly distributed on the end surface of the outer end 4111 of the sensitive element in the circumferential direction, and the four second screw holes 4118 are evenly distributed on the inner end 4112 of the sensitive element in the circumferential direction, and are connected with the elastic body mounting plane 57 The third through hole 58 is corresponding. The structure of the sensitive element 411 is shown in FIG. 4 , which is a front view of the sensitive element.

The shape of the strain gauge terminal 413 is a semicircular ring, and the two strain gauge terminals 413 can just form a circular ring and be installed on the step 4114 of the sensitive element. The leads of the strain gauge 412 are soldered to the pads on the strain gauge terminal 413 .

The sensitive element protective cover 414 is in the shape of a semicircular ring, and a wire passing hole 4141 is provided on the sensitive element protective cover 414 .

The top cover 5 includes a cylindrical structure 53 and a cylindrical boss 54 located at the center of the bottom surface of the cylindrical structure 53 and extending downward. The structure of the top cover 5 is shown in Figure 5, and Figure 5 is a structural schematic view of the top cover at a certain angle.

The upper plane of the cylindrical structure 53 is provided with several third screw holes 51, which are used to install and fix the object to be monitored. With the center of the cylindrical structure 53 as the center of the circle, several circles of evenly distributed shallow grooves 52 are provided. , used to improve the installation accuracy of the object to be monitored. As shown in Figure 1, Figure 1 is a schematic diagram of the overall structure of a strain-type six-dimensional force sensor according to an embodiment of the present invention;

Cylindrical structure grooves 55 are uniformly distributed around the cylindrical boss 54 on the bottom surface of the cylindrical structure 53 . The arrangement of the cylindrical structural groove 55 not only ensures the rigidity of the top cover 5 but also reduces the mass of the top cover 5 .

The bottom surface of the cylindrical boss 54 is provided with evenly distributed cylindrical boss grooves 56, and the outer wall of the cylindrical boss 54 is provided with four evenly distributed elastic body mounting planes 57. The installation plane 57 is connected to the end surface of the inner end 4112 of the sensitive element, and the elastic body installation plane 57 is provided with four holes uniformly distributed on the inner end 4112 of the sensitive element, corresponding to the four second screw holes 4118. a third through hole 58.

When assembling the strain-type six-dimensional force sensor, four strain gauges 412 are evenly distributed on the outer circumference of the sensitive area 4113 on the sensitive element 411, and two strain gauge terminals 413 are pasted on the plane of the step 4114 of the sensitive element, The strain gauge terminal 413 is a semicircle, and the two are put together to form a ring, and the two sensitive element protective covers 414 are fastened outside the sensitive area 4113, and the two sensitive element protective covers 414 are just assembled into a cylindrical ring , just covering the outside of the sensitive area 4113, and fixed on the sensitive element 411 by means of screw connection. The lead wire of the strain gauge 412 is welded to the strain gauge terminal 413 first, and then the lead wire from the strain gauge terminal 413 is led out to the outside of the elastic body 4 through the wire hole 4141 provided on the protective cover 414 of the sensitive element, and connected to the circuit board 3 superior. Connect the bottom cover 1 to the bottom of the base 2 by screws, the circuit board 3 is mounted on the circuit board installation plane 217 of the base 2 by screws, and the inner end 4112 of the sensitive element of the elastic body 4 is fixed by screws On the elastic body installation plane 57 of the top cover 5, the outer end 4111 of the sensitive element of the elastic body 4 is installed in the elastic body installation groove 216 of the base 2, and the first positioning pins of the base 2 are passed through first with the positioning pins The hole 218 and the second positioning pin hole 4115 of the sensitive element 411 position the elastic body 4, and then connect with screws to complete the assembly of the strain gauge six-dimensional force sensor.

When the strain gauge six-dimensional force sensor measures a certain load, the load is applied to the top cover 5 of the sensor by the screw connecting the object to be detected and the top cover 5, and then the sensitive element connecting the top cover 5 and the sensitive element 411 is connected to the screw Acting on the sensitive element 411, the transmitted load makes the sensitive area 4113 of the sensitive element 411 elastically deformed, and the deformation of the sensitive area 4113 causes the strain gauge 412 attached to the sensitive element 411 to strain accordingly, and the strain of the strain gauge 412 causes strain The sheet resistance value changes, and the changed resistance value breaks the balance of the corresponding bridge to generate an output voltage, and the size of the output voltage reflects the size of the measured load. Due to the special fabric and bridge method, when a load in a certain direction acts on the strain gauge six-dimensional force sensor, the strain gauge 412 used to measure this direction generates strain, and the bridge composed of it generates an output voltage, and the other strain gauges 412 either does not produce strain under the action of load in this direction, or even if it produces strain, the balance of the bridge composed of it does not break the output voltage and remains unchanged. Therefore, the strain gauge six-dimensional force sensor of the present invention eliminates inter-dimensional coupling structurally.

The above description of the embodiments is for those of ordinary skill in the art to understand and apply the present invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative efforts. Therefore, the present invention is not limited to the embodiments herein. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (10)

1. A strain type six-dimensional force sensor is characterized in that: it comprises a bottom cover, a base, a circuit board, an elastic body and a top cover, the bottom cover is connected with the bottom surface of the base, and the circuit board is located at the Inside the base, the four elastic bodies are evenly distributed in the base, the outer end of the sensitive element of the elastic body is connected with the base, and the inner end of the sensitive element of the elastic body is connected with the top cover, The top cover is supported on the base by elastic body. 2. The strain gauge six-dimensional force sensor according to claim 1, wherein the base comprises a cylindrical base and a base boss which is arranged on the plane of the cylindrical base and extends upward, and the base There are several U-shaped grooves on the outer edge of the base, and there are several base grooves on the outside of the base for easy handling and eyebolts are set on the base grooves, and the outer wall of the base boss is provided for installation The socket hole of the socket, the inner wall of the base boss is provided with four evenly distributed elastic body installation grooves, the elastic body installation grooves are connected with the end surface of the outer end of the sensitive element of the elastic body, and the base convex A circuit board mounting plane for mounting circuit boards is provided in the table. 3. The strain gauge six-dimensional force sensor according to claim 2, characterized in that: the outer diameter of the circuit board mounting plane is the same as the outer diameter of the circuit board; Preferably, the boss of the base is circular. 4. The strain gauge six-dimensional force sensor according to claim 2, characterized in that: the plane of the elastic body mounting groove is provided with a first positioning pin hole for positioning the position of the elastic body on the base, for The first through hole connecting the outer end of the sensitive element to the base, the four first through holes are distributed in a rectangular shape, corresponding to the first screw holes on the outer end of the sensitive element, and the first positioning pin holes are located in the four the center of the first through hole. 5. The strain gauge six-dimensional force sensor according to claim 1, characterized in that: the elastic body includes a sensitive element, a strain gauge, a strain gauge terminal, and a protective cover for the sensitive element, and the four strain gauges are all distributed on the sensitive element. On the sensitive area of the element, the two strain gauge terminals are located on the plane of the sensitive element step of the sensitive element, the two sensitive element protective covers are located outside the sensitive area, and the two sensitive element protective covers are snapped together, And the fastened sensitive element protective cover is fixed on the outer end of the sensitive element by screws, leaving a gap between the inner end of the sensitive element and the sensitive element. 6. The strain gauge six-dimensional force sensor according to claim 5, characterized in that: the sensitive element is in the shape of a dumbbell, and the outer end of the sensitive element is provided with a second through hole for fixing the protective cover of the sensitive element for positioning the elastic The second positioning pin hole at the position of the body on the base is used to connect the outer end of the sensitive element with the first screw hole of the base, and the inner end of the sensitive element is provided with a second screw hole for connecting the inner end of the sensitive element with the top cover. 7. The strain gauge six-dimensional force sensor according to claim 6, characterized in that: the second positioning pin hole is located at the center of the outer end face of the sensitive element, and the two second through holes are symmetrically distributed on the The two sides of the second positioning pin hole, the four first screw holes are evenly distributed on the outer end surface of the sensitive element in the circumferential direction, and the four second screw holes are evenly distributed on the inner end of the sensitive element in the circumferential direction on, corresponding to the third through hole on the installation plane of the elastic body; Preferably, the shape of the strain gauge terminal is a semi-circular ring, two strain gauge terminals form a circular ring and are located on the step of the sensitive element, and the lead wire of the strain gauge is welded on the pad on the strain gauge terminal; Preferably, the sensitive element protective cover is in the shape of a semi-circular ring, and a wire passing hole is provided on the sensitive element protective cover. 8 . The strain gauge six-dimensional force sensor according to claim 1 , wherein the top cover comprises a cylindrical structure and a cylindrical boss located in the center of the bottom surface of the cylindrical structure and extending downward. 9. The strain gauge six-dimensional force sensor according to claim 8, characterized in that: the upper plane of the cylindrical structure is provided with several third screw holes for the installation and fixing of the object to be monitored, with the The center of the cylindrical structure is the center of the circle, and there are several evenly distributed shallow grooves, which are used to improve the installation accuracy of the objects to be monitored; Preferably, uniformly distributed cylindrical structure grooves are arranged around the cylindrical boss on the bottom surface of the cylindrical structure. 10. The strain gauge six-dimensional force sensor according to claim 8, characterized in that: the bottom surface of the cylindrical boss is provided with evenly distributed cylindrical boss grooves, and the outer wall of the cylindrical boss There are four evenly distributed elastic body installation planes, and the elastic body installation plane is connected with the end face of the inner end of the sensitive element. four third through holes corresponding to the second screw holes.