Force detection device

Abstract

The invention discloses a force detection device. The force detection device includes: a housing; the force sensitive element is arranged in the shell and is suitable for generating elastic deformation under the action of external force; the strain gauges are attached to the force sensitive element and used for detecting the elastic deformation amount of the force sensitive element; the plurality of pins are fixed to the shell and extend into the shell; and the plurality of leads are used for electrically connecting the plurality of strain gauges and the plurality of pins into a Wheatstone bridge suitable for detecting the elastic deformation of the force sensitive element. The leads are directly and electrically connected to the strain gauges and the pins to achieve electrical connection with the strain gauges and the pins, and the multiple leads are spatially isolated from one another. According to the invention, a circuit board is not arranged in the shell, so that the internal space of the shell is saved, and more strain gauges can be arranged in the shell to improve the detection precision. In addition, the lead is directly and electrically connected with the strain gauge and the pin, so that the strain gauge can bear higher temperature, the strain gauge can be applied to a high-temperature environment, and the application range is expanded.

Description

Technical Field

[0001] The invention relates to a force detection device, in particular to a miniature force detection device. Background Art

[0002] In the prior art, a micro force detection device generally includes a housing, an elastic body, a strain gauge, a circuit board, leads and pins. The elastic body is installed in the housing, the strain gauge is attached to the elastic body, the circuit board is electrically connected to the strain gauge through the leads, and the pins are fixed to the housing and soldered to the circuit board.

[0003] For the miniature force detection device, due to its small size, in order to meet the basic space of the circuit board, the remaining space is only enough to place two strain gauges to form a Wheatstone bridge. The disadvantage of this design is that it is very sensitive to the external force applied to the shell, resulting in low detection accuracy. In addition, the pins need to be soldered to the circuit board. Since the solder paste cannot withstand excessively high temperatures, the force detection device cannot be used in high temperature environments, limiting its scope of application. Summary of the invention

[0004] The purpose of the present invention is to solve at least one aspect of the above-mentioned problems and defects in the prior art.

[0005] According to one aspect of the present invention, a force detection device is provided. The force detection device comprises: a housing; a force-sensitive element installed in the housing and adapted to undergo elastic deformation under the action of an external force; a plurality of strain gauges attached to the force-sensitive element and used to detect the elastic deformation of the force-sensitive element; a plurality of pins fixed to the housing and extending into the housing; and a plurality of leads, used to electrically connect the plurality of strain gauges and the plurality of pins into a Wheatstone bridge adapted to detect the elastic deformation of the force-sensitive element. The leads are directly electrically connected to the strain gauge and the pins to achieve electrical connection with the strain gauge and the pins, and the plurality of leads are spatially isolated from each other.

[0006] According to an exemplary embodiment of the present invention, the force detection device includes four strain gauges and four pins respectively adjacent to the four strain gauges, the four strain gauges are arranged diagonally, and the four pins are also arranged diagonally.

[0007] According to another exemplary embodiment of the present invention, the leads electrically connected between the strain gauges are at different heights and do not cross each other, so that the leads electrically connected between the strain gauges are spatially isolated from each other.

[0008] According to another exemplary embodiment of the present invention, three leads electrically connected between two adjacent strain gauges are respectively at three different heights and parallel to each other, so that the three leads electrically connected between two adjacent strain gauges are spatially isolated from each other.

[0009] According to another exemplary embodiment of the present invention, some leads electrically connected between the strain gauge and the pin are at different heights and cross each other, so that some leads electrically connected between the strain gauge and the pin are spatially isolated from each other.

[0010] According to another exemplary embodiment of the present invention, two leads respectively electrically connected to two different pins are at different heights and cross each other, so that the two leads respectively electrically connected to the two different pins are spatially isolated from each other.

[0011] According to another exemplary embodiment of the present invention, two leads electrically connected to the same pin are at different heights and do not cross each other, so that the two leads electrically connected to the same pin are spatially isolated from each other.

[0012] According to another exemplary embodiment of the present invention, the lead is directly bonded to the solder pads of the strain gauge and the pin by thermocompression bonding, ultrasonic bonding or thermoacoustic bonding; or the lead is directly welded to the solder pads of the strain gauge and the pin by thermocompression welding, ultrasonic welding or thermoacoustic welding.

[0013] According to another exemplary embodiment of the present invention, the pin has a first end located inside the shell and a second end located outside the shell; the lead is directly bonded to the first end of the pin, and the second end of the pin is used to be electrically connected to an external circuit to output a detection signal.

[0014] According to another exemplary embodiment of the present invention, the housing is an injection-molded part formed on the plurality of pins by insert injection molding, so that the housing and the plurality of pins become an integral part.

[0015] According to another exemplary embodiment of the present invention, the force-sensitive element comprises: an outer peripheral wall, which encloses an inner cavity; a central column, which is centrally arranged in the inner cavity; and a bottom wall portion, which is connected between the outer peripheral wall and the bottom of the central column. The thickness of the bottom wall portion is less than a predetermined value, so that the bottom wall portion can be elastically deformed under the action of an external force applied to the central column; the strain gauge is attached to the bottom surface of the bottom wall portion of the force-sensitive element, and is used to detect the elastic deformation amount of the bottom wall portion of the force-sensitive element.

[0016] According to another exemplary embodiment of the present invention, a top opening is formed on the top wall of the shell, and the force sensitive element is installed in the top opening of the shell; a radial step is formed on the inner circumferential surface of the top opening of the shell, and a radial flange is formed on the outer circumferential surface of the force sensitive element, and the radial flange is axially supported on the radial step of the shell.

[0017] According to another exemplary embodiment of the present invention, the outer circumferential surface of the radial flange of the force sensitive element cooperates with the inner circumferential surface of the top opening of the shell, and the outer circumferential surface of the radial flange of the force sensitive element and the inner circumferential surface of the top opening of the shell are non-circular to prevent the force sensitive element from rotating.

[0018] According to another exemplary embodiment of the present invention, a first planar portion and a second planar portion are respectively formed on the inner circumferential surface of the top opening of the shell and the outer circumferential surface of the radial flange of the force sensitive element, and the first planar portion and the second planar portion cooperate with each other to prevent the force sensitive element from rotating.

[0019] According to another exemplary embodiment of the present invention, a bottom opening is formed on the bottom of the housing, and the force detection device further includes a bottom cover installed in the bottom opening.

[0020] In the aforementioned exemplary embodiments of the present invention, no circuit board is provided in the housing, and the lead wires are directly electrically connected to the strain gauges and pins, thereby saving the internal space of the housing and enabling more strain gauges to be provided in the housing to improve the detection accuracy. In addition, since the lead wires are directly electrically connected to the strain gauges and pins, they can withstand higher temperatures, enabling the force detection device to be applied to high temperature environments, thus expanding its application range.

[0021] Other objects and advantages of the present invention will become apparent from the following description of the present invention with reference to the accompanying drawings, which will help to provide a comprehensive understanding of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic perspective view from the top showing a force detection device according to an exemplary embodiment of the present invention;

[0023] Figure 2 A schematic perspective view showing a force detection device according to an exemplary embodiment of the present invention as viewed from the bottom;

[0024] Figure 3 A schematic perspective view showing a force detection device according to an exemplary embodiment of the present invention as viewed from the bottom, wherein the bottom cover is removed;

[0025] Figure 4 A schematic perspective view showing a force detection device according to an exemplary embodiment of the present invention as viewed from the bottom, wherein the housing and the bottom cover are removed;

[0026] Figure 5 A perspective cross-sectional view showing a force detection device according to an exemplary embodiment of the present invention when viewed from the top;

[0027] Figure 6 An exploded schematic diagram showing a force detection device according to an exemplary embodiment of the present invention;

[0028] Figure 7 A perspective cross-sectional view of a force detection device according to an exemplary embodiment of the present invention as viewed from the bottom is shown. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further specifically described below by examples and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation of the present invention.

[0030] In addition, in the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the disclosed embodiments. However, it is apparent that one or more embodiments may be implemented without these specific details. In other cases, known structures and devices are embodied in a schematic manner to simplify the accompanying drawings.

[0031] According to an overall technical concept of the present invention, a force detection device is provided. The force detection device includes: a housing; a force-sensitive element installed in the housing and suitable for elastic deformation under the action of an external force; a plurality of strain gauges attached to the force-sensitive element for detecting the elastic deformation of the force-sensitive element; a plurality of pins fixed to the housing and extending into the housing; and a plurality of leads for electrically connecting the plurality of strain gauges and the plurality of pins into a Wheatstone bridge suitable for detecting the elastic deformation of the force-sensitive element. The leads are directly electrically connected to the strain gauge and the pins to achieve electrical connection with the strain gauge and the pins, and the plurality of leads are spatially isolated from each other.

[0032] Figure 1 A schematic perspective view from the top showing a force detection device according to an exemplary embodiment of the present invention; Figure 2 A schematic perspective view showing a force detection device according to an exemplary embodiment of the present invention as viewed from the bottom; Figure 3 A schematic perspective view of a force detection device according to an exemplary embodiment of the present invention as viewed from the bottom, wherein the bottom cover 6 is removed; Figure 4 A schematic perspective view of a force detection device according to an exemplary embodiment of the present invention as viewed from the bottom, wherein the housing 1 and the bottom cover 6 are removed; Figure 5 A perspective cross-sectional view showing a force detection device according to an exemplary embodiment of the present invention when viewed from the top; Figure 6An exploded schematic diagram showing a force detection device according to an exemplary embodiment of the present invention; Figure 7 A perspective cross-sectional view of a force detection device according to an exemplary embodiment of the present invention as viewed from the bottom is shown.

[0033] like Figures 1 to 7 As shown, in an exemplary embodiment of the present invention, a force detection device is disclosed. The force detection device includes: a housing 1, a force sensitive element 2, a plurality of strain gauges 3, a plurality of pins 4 and a plurality of leads 5. The force sensitive element 2 is installed in the housing 1 and is suitable for elastic deformation under the action of an external force. A plurality of strain gauges 3 are attached to the force sensitive element 2 for detecting the elastic deformation of the force sensitive element 2. The elastic deformation is also called strain. A plurality of pins 4 are fixed to the housing 1 and extend into the housing 1. A plurality of leads 5 are used to electrically connect a plurality of strain gauges 3 and a plurality of pins 4 into a Wheatstone bridge suitable for detecting the elastic deformation of the force sensitive element 2. The leads 5 are directly bonded to the strain gauge 3 and the pins 4 to achieve electrical connection with the strain gauge 3 and the pins 4, and the plurality of leads 5 are spatially isolated from each other.

[0034] In the present invention, since the lead wire 5 is directly bonded to the strain gauge 3 and the pin 4, there is no need to set a circuit board in the housing 1, thereby saving the internal space of the housing 1, so that more strain gauges 3 can be set in the housing 1 to improve the detection accuracy. In addition, since the lead wire 5 is directly bonded to the strain gauge 3 and the pin 4, it can withstand higher temperatures, so that the force detection device can be used in high temperature environments, expanding its application range.

[0035] like Figures 1 to 7 As shown, in the illustrated embodiment, the force detection device includes four strain gauges 3 and four pins 4 respectively adjacent to the four strain gauges 3, the four strain gauges 3 are arranged diagonally, and the four pins 4 are also arranged diagonally. However, please note that the arrangement of the strain gauges 3 and the pins 4 of the present invention is not limited to the illustrated embodiment, and other arrangements may be adopted according to actual needs.

[0036] like Figures 1 to 7 As shown, in the illustrated embodiment, the leads 5 electrically connected between the strain gauges 3 are at different heights and do not cross each other, so that the leads 5 electrically connected between the strain gauges 3 are spatially isolated from each other.

[0037] like Figures 1 to 7 As shown, in the illustrated embodiment, the three leads 5 electrically connected between two adjacent strain gauges 3 are respectively at three different heights and parallel to each other, so that the three leads 5 electrically connected between two adjacent strain gauges 3 are spatially isolated from each other.

[0038] like Figures 1 to 7As shown, in the illustrated embodiment, some leads 5 electrically connected between the strain gauge 3 and the pin 4 are at different heights and cross each other, so that some leads 5 electrically connected between the strain gauge 3 and the pin 4 are spatially isolated from each other.

[0039] like Figures 1 to 7 As shown, in the illustrated embodiment, two leads 5 respectively electrically connected to two different pins 4 are at different heights and cross each other, so that the two leads 5 respectively electrically connected to two different pins 4 are spatially isolated from each other.

[0040] like Figures 1 to 7 As shown, in the illustrated embodiment, the two leads 5 electrically connected to the same pin 4 are at different heights and do not cross each other, so that the two leads 5 electrically connected to the same pin 4 are spatially isolated from each other.

[0041] like Figures 1 to 7 As shown, in an exemplary embodiment of the present invention, the lead 5 can be directly bonded to the pads of the strain gauge 3 and the pin 4 by thermocompression bonding, ultrasonic bonding or thermoacoustic bonding.

[0042] like Figures 1 to 7 As shown, in another exemplary embodiment of the present invention, the lead wire 5 can be directly welded to the pads of the strain gauge 3 and the pin 4 by thermocompression welding, ultrasonic welding or thermosonic welding.

[0043] like Figures 1 to 7 As shown, in the illustrated embodiment, the pin 4 has a first end 4a located inside the housing 1 and a second end 4b located outside the housing 1. The lead 5 is directly bonded to the first end 4a of the pin 4, and the second end 4b of the pin 4 is used to be electrically connected to an external circuit (not shown) to output a detection signal, such as a voltage signal.

[0044] like Figures 1 to 7 As shown, in the illustrated embodiment, the housing 1 is an injection molded part formed on the plurality of pins 4 by insert injection molding, so that the housing 1 and the plurality of pins 4 become an integral part.

[0045] like Figures 1 to 7 As shown, in the illustrated embodiment, the force sensitive element 2 includes: an outer peripheral wall 21, a central column 22 and a bottom wall portion 23. The outer peripheral wall 21 encloses an inner cavity 201. The central column 22 is centrally disposed in the inner cavity 201. The bottom wall portion 23 is connected between the outer peripheral wall 21 and the bottom of the central column 22. The thickness of the bottom wall portion 23 is less than a predetermined value, so that the bottom wall portion 23 can be elastically deformed under the action of an external force applied to the central column 22. The strain gauge 3 is attached to the bottom surface of the bottom wall portion 23 of the force sensitive element 2, and is used to detect the elastic deformation amount of the bottom wall portion 23 of the force sensitive element 2.

[0046] like Figures 1 to 7 As shown, in the illustrated embodiment, a top opening 101 is formed on the top wall of the housing 1, and the force sensitive element 2 is installed in the top opening 101 of the housing 1. A radial step 14 is formed on the inner circumference of the top opening 101 of the housing 1, and a radial flange 24 is formed on the outer circumference of the force sensitive element 2, and the radial flange 24 is axially supported on the radial step 14 of the housing 1.

[0047] like Figures 1 to 7 As shown, in the illustrated embodiment, the outer circumferential surface of the radial flange 24 of the force sensitive element 2 cooperates with the inner circumferential surface of the top opening 101 of the shell 1, and the outer circumferential surface of the radial flange 24 of the force sensitive element 2 and the inner circumferential surface of the top opening 101 of the shell 1 are non-circular to prevent the force sensitive element 2 from rotating.

[0048] like Figures 1 to 7 As shown, in the illustrated embodiment, a first planar portion 14a and a second planar portion 24a are respectively formed on the inner circumferential surface of the top opening 101 of the shell 1 and on the outer circumferential surface of the radial flange 24 of the force sensitive element 2, and the first planar portion 14a and the second planar portion 24a cooperate with each other to prevent the force sensitive element 2 from rotating.

[0049] like Figures 1 to 7 As shown, in the illustrated embodiment, a bottom opening 102 is formed on the bottom of the housing 1 , and the force detection device further includes a bottom cover 6 installed in the bottom opening 102 .

[0050] The assembly process of the force detection device will be briefly described below with reference to the accompanying drawings.

[0051] First, attach the strain gauge 3 to the bottom surface of the force sensitive element 2;

[0052] Then, the force-sensitive element 2 is installed into the top opening 101 of the housing 1;

[0053] Then, the lead wire 5 is electrically connected to the strain gauge 3 and the pin 4 through the bottom opening 102 on the housing 1;

[0054] Finally, the bottom cover 6 is installed into the bottom opening 102 of the housing 1 .

[0055] Those skilled in the art will appreciate that the embodiments described above are exemplary and may be improved upon by those skilled in the art. The structures described in the various embodiments may be freely combined without causing any conflicts in structure or principle, and these changes should fall within the scope of protection of the present invention.

[0056] Although the present invention has been described in conjunction with the accompanying drawings, the embodiments disclosed in the accompanying drawings are intended to exemplify the preferred implementations of the present invention and should not be construed as limiting the present invention.

[0057] Although some embodiments of the general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the claims and their equivalents.

[0058] It should be noted that the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. In addition, any element reference signs in the claims shall not be construed as limiting the scope of the present invention.

Claims

1. A force detection device, characterized in that: include: Housing (1); A force-sensitive element (2) is installed in the housing (1) and is suitable for elastically deforming under the action of an external force; A plurality of strain gauges (3) are attached to the force-sensitive element (2) and are used to detect the elastic deformation of the force-sensitive element (2); A plurality of pins (4) fixed to the housing (1) and extending into the housing (1); and a plurality of leads (5) for electrically connecting the plurality of strain gauges (3) and the plurality of pins (4) to form a Wheatstone bridge suitable for detecting the elastic deformation of the force sensitive element (2); The lead wire (5) is directly electrically connected to the strain gauge (3) and the pin (4) to achieve electrical connection with the strain gauge (3) and the pin (4), and the plurality of lead wires (5) are spatially isolated from each other.

2. The force detection device according to claim 1, characterized in that: The force detection device comprises four strain gauges (3) and four pins (4) respectively adjacent to the four strain gauges (3); the four strain gauges (3) are arranged diagonally, and the four pins (4) are also arranged diagonally.

3. The force detection device according to claim 1, characterized in that: The leads (5) electrically connected between the strain gauges (3) are respectively located at different heights and do not cross each other, so that the leads (5) electrically connected between the strain gauges (3) are spatially isolated from each other.

4. The force detection device according to claim 3, characterized in that: The three leads (5) electrically connected between two adjacent strain gauges (3) are respectively located at three different heights and are parallel to each other, so that the three leads (5) electrically connected between two adjacent strain gauges (3) are spatially isolated from each other.

5. The force detection device according to claim 1, characterized in that: Some leads (5) electrically connected between the strain gauge (3) and the pin (4) are respectively at different heights and cross each other, so that some leads (5) electrically connected between the strain gauge (3) and the pin (4) are spatially isolated from each other.

6. The force detection device according to claim 5, characterized in that: Two leads (5) electrically connected to two different pins (4) are at different heights and cross each other, so that the two leads (5) electrically connected to two different pins (4) are spatially isolated from each other.

7. The force detection device according to claim 5, characterized in that: The two leads (5) electrically connected to the same pin (4) are at different heights and do not cross each other, so that the two leads (5) electrically connected to the same pin (4) are spatially isolated from each other.

8. The force detection device according to claim 1, characterized in that: The lead wire (5) is directly bonded to the pads of the strain gauge (3) and the lead (4) by thermocompression bonding, ultrasonic bonding or thermoacoustic bonding; or The lead wire (5) is directly welded to the welding pads of the strain gauge (3) and the pin (4) by means of hot pressing welding, ultrasonic welding or thermosonic welding.

9. The force detection device according to claim 1, characterized in that: The pin (4) has a first end (4a) located inside the housing (1) and a second end (4b) located outside the housing (1); The lead wire (5) is directly bonded to the first end (4a) of the pin (4), and the second end (4b) of the pin (4) is used to be electrically connected to an external circuit to output a detection signal.

10. The force detection device according to claim 1, characterized in that: The housing (1) is an injection-molded part that is molded on the plurality of pins (4) by means of embedded injection molding, so that the housing (1) and the plurality of pins (4) form an integral part.

11. The force detection device according to any one of claims 1 to 10, characterized in that: The force sensitive element (2) comprises: An outer peripheral wall (21) encloses an inner cavity (201); a central column (22) centrally disposed in the inner cavity (201); and A bottom wall portion (23) is connected between the outer peripheral wall (21) and the bottom of the central column (22). The thickness of the bottom wall portion (23) is less than a predetermined value, so that the bottom wall portion (23) can be elastically deformed under the action of an external force applied to the center column (22); the strain gauge (3) is attached to the bottom surface of the bottom wall portion (23) of the force sensitive element (2) and is used to detect the elastic deformation of the bottom wall portion (23) of the force sensitive element (2).

12. The force detection device according to claim 11, characterized in that: A top opening (101) is formed on the top wall of the housing (1), and the force-sensitive element (2) is installed in the top opening (101) of the housing (1); A radial step (14) is formed on the inner circumferential surface of the top opening (101) of the shell (1), and a radial flange (24) is formed on the outer circumferential surface of the force sensitive element (2), and the radial flange (24) is axially supported on the radial step (14) of the shell (1).

13. The force detection device according to claim 12, characterized in that: The outer circumference of the radial flange (24) of the force-sensitive element (2) cooperates with the inner circumference of the top opening (101) of the shell (1), and the outer circumference of the radial flange (24) of the force-sensitive element (2) and the inner circumference of the top opening (101) of the shell (1) are non-circular to prevent the force-sensitive element (2) from rotating.

14. The force detection device according to claim 13, characterized in that: A first planar portion (14a) and a second planar portion (24a) are respectively formed on the inner circumferential surface of the top opening (101) of the shell (1) and the outer circumferential surface of the radial flange (24) of the force sensitive element (2), and the first planar portion (14a) and the second planar portion (24a) cooperate with each other to prevent the force sensitive element (2) from rotating.

15. The force detection device according to claim 11, characterized in that: A bottom opening (102) is formed on the bottom of the housing (1), and the force detection device further comprises a bottom cover (6) installed in the bottom opening (102).

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