Precision drive screwdriver

Abstract

The application provides a precise transmission electric screwdriver, which comprises a shell, a sensor body, a main shaft and a transmission assembly. The precise transmission electric screwdriver of the application is sleeved with the sensor body on the outer ring of the main shaft, and the motor and the main shaft are connected and driven inside the sensor body, so that the force consumption and torque loss at the connection between the motor and the main shaft are avoided. The top end of the sensor body is connected with a rotating part, and a transmission assembly is arranged between the top end of the sensor body and the rotating part. Through the connection of the transmission assembly, the close cooperation between the sensor body and the rotating part is realized. The connection design ensures the accurate torque transmission and accurate collection of sensor data. Through the connection between the top end of the sensor body and the rotating part and the bottom end and the shell, the sensor can directly contact and perceive the torque force, so as to accurately collect the meridian torque data and avoid the inaccurate detection problem existing in the traditional electric screwdriver.

Description

Technical Field

[0001] This invention relates to the field of electric screwdrivers, and in particular to an electric screwdriver with precise transmission. Background Technology

[0002] An electric screwdriver, also known as an electric screwdriver or electric screwdriver, is a power tool used to tighten and loosen screws and nuts. It is an indispensable tool in the assembly industry.

[0003] In traditional electric screwdrivers, the sensor is usually located at the motor output. This may result in some force loss and torque loss at the connection between the motor and the spindle, leading to inaccurate torque detection results.

[0004] Therefore, it is necessary to provide an electric screwdriver with precise transmission to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a precision-driven electric screwdriver to solve the problem that in the prior art, the electric screwdriver sensor is usually located at the motor output, which results in a certain amount of force consumption and torque loss at the connection between the motor and the spindle, leading to inaccurate torque detection results.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: an electric screwdriver with precise transmission, comprising:

[0007] shell;

[0008] An electric motor is disposed inside the housing, and a rotating part is provided at the bottom end of the electric motor, and a drive shaft is provided on the rotating part;

[0009] A main spindle, disposed within the housing, is connected at one end to the drive shaft and at the other end to a bit; and

[0010] The sensor body has a hollow cylindrical structure, and a strain gauge is provided in the middle of the sensor body. The strain gauge is used to collect meridional torque data.

[0011] A transmission assembly is provided between the top of the sensor and the rotating part. The top of the sensor body is connected to the rotating part through the transmission assembly. The sensor body is sleeved on the outer ring of the main shaft, and the bottom of the sensor body is connected to the outer shell.

[0012] In this invention, the transmission assembly includes:

[0013] A connecting flange, the bottom end of which is connected to the sensor body, and the top end of which is connected to the rotating part; and

[0014] A steel ring is fitted around the outer ring of the connecting flange, and the outer ring of the steel ring is in contact with the inner wall of the outer shell.

[0015] In this invention, the transmission assembly further includes a steel shaft, which is disposed between the outer ring of the connecting flange and the inner wall of the steel ring, and the axial extension direction of the steel shaft is parallel to the axial extension direction of the main shaft.

[0016] In this invention, a first groove is provided on the outer side of the connecting flange, the steel shaft is received in the first groove, and one side of the outer surface of the steel shaft is in contact with the inner wall of the steel ring.

[0017] In this invention, the transmission assembly further includes a steel sheet disposed between the top of the connecting flange and the rotating part, and the bottom surface of the steel sheet defines the position of the top surface of the steel shaft.

[0018] In this invention, the sensor body includes:

[0019] A first connecting part is located at the top of the sensor body, and the first connecting part is connected to the connecting flange;

[0020] A second connecting part is located at the bottom end of the sensor body, and the second connecting part is connected to the outer casing; and

[0021] The deformation section is located in the middle of the sensor body, and the cross-sectional diameter of the deformation section is smaller than the cross-sectional diameter of the first connecting section and the cross-sectional diameter of the second connecting section. The deformation section is connected to a strain device on its outer side.

[0022] In this invention, the first connecting part is provided with a plug-in groove;

[0023] The connecting flange includes:

[0024] A first fixing part is inserted into the insertion slot, and the first fixing part is connected to the first connecting part; and

[0025] The second fixing part is located above the first connecting part, and the second fixing part is connected to the rotating part.

[0026] In this invention, a first limiting ring is provided on the outer side of the main shaft;

[0027] The second connecting portion is provided with a first fixing groove and a second fixing groove, the first fixing groove being located above the second fixing groove, and the cross-sectional diameter of the first fixing groove being less than or equal to the cross-sectional diameter of the second fixing groove; the electric screwdriver further includes:

[0028] A horizontal bearing assembly, sleeved outside the main shaft and located above the first limiting ring, rotatably connects the top surface of the first limiting ring to the top wall of the first fixing groove; and

[0029] A longitudinal bearing assembly is sleeved on the outside of the main shaft and located below the first limiting ring. The longitudinal bearing assembly rotatably connects the outer surface of the main shaft to the side wall of the second fixing groove.

[0030] In this invention, the outer ring of the spindle is provided with a first groove, the first groove is located below the longitudinal bearing assembly, the first groove is connected to the retaining ring, and the retaining ring is used to support the longitudinal bearing assembly.

[0031] In this invention, the outer shell includes:

[0032] The main housing is a hollow cylindrical structure with an opening at its bottom. The motor is located inside the main housing, and the outer side of the second connecting part is connected to the main housing.

[0033] A front cover is connected to the main housing and is used to close the opening. The bottom end of the sensor body is connected to the front cover.

[0034] Compared to existing technologies, the advantages of this invention are as follows: The precision-driven electric screwdriver of this invention uses a sensor body fitted around the outer ring of the spindle. The motor and spindle are connected and driven inside the sensor body, avoiding force consumption and torque loss at the connection between the motor and the spindle. The top of the sensor body connects to the rotating part, and a transmission assembly is provided between the top of the sensor body and the rotating part. This transmission assembly ensures a tight fit between the sensor body and the rotating part. This connection design guarantees precise torque transmission and accurate acquisition of sensor data. Through the connection between the top of the sensor body and the rotating part, and the bottom of the sensor body and the outer shell, the sensor can directly contact and sense the torque force, thereby accurately acquiring radial torque data. The bottom of the sensor body connects to the outer shell: through this connection, the sensor body maintains a stable position during operation, preventing displacement or loosening, ensuring the accuracy of sensor acquisition. Directly connecting the sensor body to the spindle and the rotating part achieves more accurate and reliable torque detection, avoiding the inaccurate detection problems present in traditional electric screwdrivers.

[0035] The transmission assembly incorporates a steel ring on the periphery of the connecting flange, which contacts the outer casing. This steel ring can rotate relative to the upper surface of the sensor body, thus ensuring that it does not affect the measurement of torque by the deformation plane. The structure of the connecting flange and steel ring effectively prevents external interference from affecting the sensor body. The steel ring, located between the top of the sensor body and the rotating part, forms a physical barrier, preventing external interference from entering the sensor body area and improving the stability and accuracy of the sensor. When the lower part of the sensor body receives a horizontal force, the force is first applied to the outer casing through the steel ring. If the outer casing has high rigidity, it can protect the deformation plane of the sensor body from the influence of the horizontal force, ensuring the accuracy of the sensor's detection. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments are briefly introduced below. The drawings described below are only the corresponding drawings of some embodiments of the present invention.

[0037] Figure 1 This is a schematic diagram of the overall structure of the electric screwdriver according to a preferred embodiment of the present invention.

[0038] Figure 2 This is a cross-sectional view of the overall structure of the electric screwdriver according to a preferred embodiment of the present invention.

[0039] Figure 3 This is an exploded view of the electric screwdriver structure according to a preferred embodiment of the present invention.

[0040] Figure 4 This is a schematic diagram of the sensor body and connecting flange according to a preferred embodiment of the present invention.

[0041] Figure 5 This is a cross-sectional view of the overall structure of the electric screwdriver according to a preferred embodiment of the present invention.

[0042] Figure 6 for Figure 2 A magnified view of the local structure.

[0043] Figure 7 A schematic cross-section of the sleeve in use according to a preferred embodiment of the present invention. Figure 1 .

[0044] Figure 8 A schematic cross-section of the sleeve in use according to a preferred embodiment of the present invention. Figure 2 .

[0045] Reference numerals: 11. Outer shell; 111. Main shell; 1111. Third screw hole; 112. Front cover; 1121. Fourth screw hole; 113. Third screw; 114. Fourth screw; 12. Motor; 121. Rotating part; 1211. Drive shaft; 13. Main shaft; 131. First mounting groove; 132. First limiting ring; 133. Second mounting groove; 134. Positioning hole; 135. Snap ring; 136. First positioning groove; 14. Screwdriver bit; 141. Second positioning groove; 15. Sensor body; 151. First connecting part; 1511. Insertion groove; 1512. First clearance groove; 152. Deformation part; 153. Second connecting part; 1531. Second connecting groove; 15 33. Sealing groove; 1534. First fixing groove; 1535. Second fixing groove; 16. Connecting flange; 161. First fixing part; 1611. Second clearance groove; 162. Second fixing part; 1622. First groove; 1623. Second screw; 1624. First screw; 17. Steel shaft; 18. Steel ring; 191. Horizontal bearing assembly; 1911. Upper steel ring; 1912. Lower steel ring; 1913. Second steel ball; 192. Longitudinal bearing assembly; 1921. Inner steel ring; 1922. Outer steel ring; 1923. First steel ball; 193. Sliding sleeve; 1931. Receiving groove; 194. Positioning ball; 195. Elastic element; 196. Elastic retaining ring; 20. Steel sheet. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] The directional terms mentioned in this invention, such as "up", "down", "front", "back", "left", "right", "inner", "outer", "side", "top" and "bottom", are only for reference to the orientation of the accompanying drawings. The directional terms used are for the purpose of explaining and understanding this invention, and are not intended to limit this invention.

[0048] The terms "first" and "second" used in the terminology of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, nor as limiting the order of events.

[0049] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0050] The following is a preferred embodiment of an electric screwdriver for precise transmission that can solve the above-mentioned technical problems provided by the present invention.

[0051] Please refer to Figure 1 , Figure 2 and Figure 3 ,in Figure 1 This is a schematic diagram of the overall structure of the electric screwdriver according to a preferred embodiment of the present invention. Figure 2 This is a cross-sectional view of the overall structure of the electric screwdriver according to a preferred embodiment of the present invention. Figure 3 This is an exploded view of the electric screwdriver structure according to a preferred embodiment of the present invention.

[0052] In the diagram, units with similar structures are represented by the same labels.

[0053] This invention provides an electric screwdriver, comprising a housing 11, a motor 12, a spindle 13, and a sensor body 15. The motor 12 is housed within the housing 11, with a rotating part 121 at its bottom and a drive shaft 1211 mounted thereon. The spindle 13 is also housed within the housing 11, with one end connected to the drive shaft 1211 and the other end having a screwdriver bit 14. The sensor body 15 is a hollow cylindrical structure, with a strain gauge located in its center for collecting radial torque data. A transmission assembly is provided between the top of the sensor body 15 and the rotating part 121, connecting the top of the sensor body 15 to the rotating part 121. The sensor body 15 is fitted around the outer ring of the spindle 13, and its bottom end is connected to the housing 11.

[0054] The sensor body 15 is sleeved on the outer ring of the main shaft 13. The top end of the sensor body 15 is connected to the rotating part 121, and the bottom end of the sensor body 15 is connected to the outer shell 11.

[0055] The sensor body 15 enables the electric screwdriver to acquire radial torque data in real time, accurately monitoring and recording the torque magnitude during operation. The sensor body 15 is fitted around the outer ring of the spindle 13. The motor 12 and spindle 13 are connected and driven internally within the sensor body 15, ensuring stable rotation of the screwdriver bit 14 by the spindle 13. The top of the sensor body 15 connects to the rotating part 121, and the bottom connects to the outer casing 11, forming a tight structural connection. Torque is generated between the upper part of the sensor body 15 and the lower part of the sensor, effectively transmitting torque force for detection and avoiding energy loss and sensor displacement. This electric screwdriver, with its key components including the outer casing 11, motor 12, spindle 13, and sensor body 15, meets the normal operating requirements of the electric screwdriver while ensuring accurate acquisition and transmission of torque data. The electric screwdriver acquires radial torque data through the strain gauge of the sensor body, improving the accuracy and reliability during operation and achieving more efficient work.

[0056] The transmission assembly in this embodiment will be described in detail below:

[0057] Combination Figure 4 and Figure 5 In this embodiment, the transmission assembly includes a connecting flange 16, a steel shaft 17, a steel ring 18, and a steel sheet 20; wherein the bottom end of the connecting flange 16 in the transmission assembly is connected to the sensor body 15, and the top end of the connecting flange 16 is connected to the rotating part 121; the steel ring 18 is fitted on the outer ring of the connecting flange 16, and the outer ring of the steel ring 18 is in contact with the inner wall of the outer shell 11.

[0058] By providing a steel ring 18 that contacts the outer casing 11 around the periphery of the connecting flange 16, the steel ring 18 can rotate relative to the upper surface of the sensor body 15. Therefore, the steel ring 18 does not affect the measurement of torque by the deformation plane. The structure of the connecting flange 16 and the steel ring 18 effectively prevents external interference from affecting the sensor body 15. The steel ring 18, located between the top of the sensor body 15 and the rotating part 121, forms a physical barrier, preventing external interference from entering the sensor body 15 area and improving the stability and accuracy of the sensor body 15. When the lower part of the sensor body 15 is subjected to a horizontal force, the force is first applied to the outer casing 11 through the steel ring 18. If the outer casing 11 has high hardness, it can protect the deformation plane of the sensor body 15 from the influence of the horizontal force, ensuring the accuracy of the sensor body 15's detection.

[0059] Furthermore, the transmission assembly also includes a steel shaft 17, which is disposed between the outer ring of the connecting flange 16 and the inner wall of the steel ring 18. The axial extension direction of the steel shaft 17 is parallel to the axial extension direction of the main shaft 13. The steel shaft 17 ensures the rotation of the connecting flange 16 relative to the steel shaft 17, improving the stability of the connecting flange 16 structure during the use of the electric screwdriver.

[0060] Furthermore, a first groove 1622 is provided on the outer side of the connecting flange 16, and the steel shaft 17 is housed in the first groove 1622, which improves the stability of the connection between the connecting flange 16 and the steel shaft 17. One side of the outer surface of the steel shaft 17 is in contact with the inner wall of the steel ring 18, ensuring the stable rotation of the steel shaft 17.

[0061] The transmission assembly also includes a steel plate 20, which is disposed between the top of the connecting flange 16 and the rotating part 121. The bottom surface of the steel plate 20 defines the position of the top surface of the steel shaft 17. In this embodiment, the bottom end of the steel shaft 17 is supported by the top surface of the sensor body 15, and the top end of the steel shaft 17 is limited by the steel plate 20 to prevent the steel shaft 17 from falling off. In addition, in this embodiment, the steel plate 20 and the connecting flange 16 are connected by a first screw 1624 for easy assembly and disassembly.

[0062] The sensor body 15 in this embodiment will be described in detail below:

[0063] Combination Figure 2 The sensor body 15 includes a first connecting part 151, a second connecting part 153, and a deformation part 152. The first connecting part 151 is located at the top of the sensor body 15 and is connected to a connecting flange 16. The second connecting part 153 is located at the bottom of the sensor body 15 and is connected to a housing 11. The deformation part 152 is located in the middle of the sensor body 15, and the cross-sectional diameter of the deformation part 152 is smaller than the cross-sectional diameters of the first connecting part 151 and the second connecting part 153. A strain gauge is connected to the outside of the deformation part 152. The upper part of the sensor body 15 is connected to the output of the motor 12 through the connecting flange 16. The lower part of the sensor body 15 is connected to the housing 11. The strain gauge installed in the deformation part 152 can detect the torque difference between the upper and lower parts of the sensor.

[0064] Combination Figure 3 and Figure 4 The connection between the sensor body 15 and the connecting flange 16 is described below:

[0065] The first connecting portion 151 is provided with a insertion groove 1511; the connecting flange 16 includes a first fixing portion 161 and a second fixing portion 162; the first fixing portion 161 is inserted into the insertion groove 1511 and connected to the first connecting portion 151; the second fixing portion 162 is located above the first connecting portion 151 and is connected to the rotating portion 121. In this embodiment, the first connecting portion 151 and the first fixing portion 161 of the connecting flange 16 are also connected by a second screw 1623, which improves the stability of the connection between the connecting flange 16 and the sensor body 15.

[0066] Furthermore, the second fixing part 162 and the rotating part 121 are connected by the first screw 1624, which facilitates the assembly and disassembly of the sensor body 15 and the connecting flange 16. The top of the first connecting part 151 is also provided with a first clearance groove 1512, which is used to accommodate the first screw 1624 and improve the stability of the connection between the sensor body 15 and the connecting flange 16.

[0067] In this embodiment, the first fixing part 161 is provided with a second relief groove 1611, which is spliced ​​with the first relief groove 1512 to engage the first screw 1624, thereby increasing the contact surface between the first connecting part 151 and the connecting flange 16 connected by the first screw 1624, and making the structural connection more stable.

[0068] In this embodiment, the second fixing part 162 is provided with a first groove 1622 on its periphery. The electric screwdriver also includes a steel shaft 17, which is disposed in the first groove 1622. One side of the outer surface of the steel shaft 17 is in contact with the inner wall of the outer casing 11, thereby ensuring the stability of the connecting flange 16 relative to the outer casing 11.

[0069] In this embodiment, several groups of steel shafts 17 are provided, and the steel shafts 17 are arranged in a ring array around the connecting flange 16, which improves the stability of the electric screwdriver during use.

[0070] In the preferred embodiment, the second fixing part 162 is fitted with a steel ring 18 on its outer ring, and the steel shaft 17 moves relative to the steel ring 18. The steel ring 18 prevents the outer shell 11 from being deformed, thereby affecting the detection accuracy of the sensor body 15.

[0071] Combination Figure 2 and Figure 6 The connection structure between the sensor body 15 and the main shaft 13 is described below:

[0072] A first limiting ring 132 is provided on the outer side of the main shaft 13, and a first fixing groove 1534 and a second fixing groove 1535 are provided on the inner ring of the second connecting part 153 of the sensor body 15. The first fixing groove 1534 is located above the second fixing groove 1535, and the cross-sectional diameter of the first fixing groove 1534 is less than or equal to the cross-sectional diameter of the second fixing groove 1535.

[0073] The electric screwdriver in this embodiment includes a horizontal bearing assembly 191 and a vertical bearing assembly 192. The horizontal bearing assembly 191 is sleeved on the outside of the spindle 13 and is located above the first limiting ring 132. The horizontal bearing assembly 191 rotatably connects the top surface of the first limiting ring 132 to the top wall of the first fixing groove 1534. The vertical bearing assembly 192 is sleeved on the outside of the spindle 13 and is located below the first limiting ring 132. The vertical bearing assembly 192 rotatably connects the outer surface of the spindle 13 to the side wall of the second fixing groove 1535.

[0074] The electric screwdriver, through the arrangement of the first limiting ring 132, the horizontal bearing assembly 191, and the longitudinal bearing assembly 192, achieves stable transmission between the spindle 13 and the sensor body 15. The inner ring of the sensor body 15 is provided with a first fixing groove 1534 and a second fixing groove 1535, wherein the cross-sectional diameter of the first fixing groove 1534 is less than or equal to the cross-sectional diameter of the second fixing groove 1535. This design enhances the connection stability between the sensor body 15 and the spindle 13. While ensuring accurate sensor detection of the spindle 13's transmission, the horizontal bearing assembly 191 and the longitudinal bearing assembly 192 effectively protect the spindle 13 from impacts from external forces in various directions. During use, the electric screwdriver applies downward pressure when screwing; the horizontal bearing assembly 191 and the longitudinal bearing assembly 192 prevent rotational wear between the sensor body 15 and the spindle 13. This structure reduces friction and vibration during transmission.

[0075] The longitudinal bearing assembly 192 includes an inner steel ring 1921, an outer steel ring 1922, and first steel balls 1923. The inner steel ring 1921 is sleeved on the spindle 13, and a first receiving groove is provided on the outer side of the inner steel ring 1921. The outer steel ring 1922 is disposed in a second fixed groove 1535, and a second receiving groove is provided on the inner side of the outer steel ring 1922, which corresponds to the first receiving groove. A plurality of first steel balls 1923 are provided, and the plurality of first steel balls 1923 are rotatably disposed between the inner steel ring 1921 and the outer steel ring 1922. One side of the first steel ball 1923 is received in the first receiving groove, and the other side of the first steel ball 1923 is received in the second receiving groove. The relative movement of the inner steel ring 1921 and the outer steel ring 1922 prevents the spindle 13 from shifting in the left and right directions.

[0076] Furthermore, the electric screwdriver in this embodiment also includes a retaining ring 135, which is sleeved on the spindle 13 and located below the longitudinal bearing assembly 192. The linear retaining ring is used to support and limit the position of the longitudinal bearing assembly 192, thereby improving the stability of the electric screwdriver.

[0077] The outer ring of the spindle 13 is provided with a first groove, and the retaining ring 135 is embedded in the first groove to prevent the retaining ring 135 from falling off the spindle 13.

[0078] In this embodiment, the horizontal bearing assembly 191 includes an upper steel ring 1911, a lower steel ring 1912, and a second steel ball 1913. The upper steel ring 1911 and the lower steel ring 1912 are both sleeved on the main shaft 13, and the top surface of the upper steel ring 1911 is in contact with the top surface of the first fixing groove 1534, and the bottom surface of the lower steel ring 1912 is connected to the top surface of the first limiting ring 132. The second steel ball 1913 is rotatably disposed between the upper steel ring 1911 and the lower steel ring 1912. The horizontal bearing assembly 191 prevents the main shaft 13 from shifting in the vertical direction.

[0079] Combination Figure 1 and Figure 3 The connection structure between sensor 15 and housing 11 is described below:

[0080] In this embodiment, a second connecting groove 1531 is provided on the outer side of the second connecting part 153, and a third screw hole 1111 is provided on the side of the outer shell 11. The sensor body 15 is connected to the second connecting groove 1531 by a third screw 113 passing through the third screw hole 1111, which improves the stability of the sensor body 15 installation.

[0081] Furthermore, in this embodiment, the outer casing 11 includes a main casing 111 and a front cover 112. The main casing 111 is a hollow cylindrical structure with an opening at its bottom. The motor 12 is located inside the main casing 111, and a third screw hole 1111 is located around the main casing 111. The front cover 112 is connected to the main casing 111 and is used to close the opening. The sensor body 15 has a third connecting groove at its bottom, and the front cover 112 has a fourth screw hole 1121. The sensor body 15 is connected to the third connecting groove via a fourth screw 114 passing through the fourth screw hole 1121. The connection between the bottom of the sensor body 15 and the front cover 112 increases the contact surface between the sensor body 15 and the outer casing 11, ensuring the accuracy of the sensor body 15's detection.

[0082] In this embodiment, the bottom end of the outer steel ring 1922 contacts the top surface of the front cover 112. The first limiting ring 131 and the front cover 112 limit and clamp the longitudinal bearing assembly 192, which improves the practicality of the longitudinal bearing assembly 192. The longitudinal bearing assembly 192 can also prevent wear between the sensor body 15 and the main shaft 13.

[0083] In this embodiment, a sealing groove 1533 is also provided on the outer side of the second connecting part 153 of the sensor body 15. The sealing groove 1533 is used to embed the sealing ring to improve the sealing and stability of the connection between the bottom end of the sensor body 15 and the outer shell 11.

[0084] Combination Figure 2 and Figure 6 The connection between the spindle 13 and the motor 12 in this embodiment will be described as follows:

[0085] In this embodiment, a first mounting groove 131 is provided at the top of the main shaft 13, and the drive shaft 1211 is inserted into the first mounting groove 131 to facilitate the assembly of the sensor body 15 and the main shaft 13. In this embodiment, the cross-section of the mounting groove 131 can be a polygonal structure such as a triangle or quadrilateral. The cross-sectional structure of the drive shaft 1211 matches the cross-section of the first mounting groove 131, which improves the stability of the insertion between the main shaft 13 and the first mounting groove 131 and avoids wear errors between the main shaft 13 and the drive shaft 1211.

[0086] Combination Figure 6 , Figure 7 and Figure 8 The connection between the spindle 13 and the bit 14 in this embodiment will be described as follows:

[0087] In this embodiment, the bottom end of the spindle 13 is provided with a second mounting groove 133. The bit 14 is inserted into the second mounting groove 133 and the bit 14 is inserted into the spindle 13 for easy replacement of different types of bit 14.

[0088] Furthermore, a positioning hole 134 is provided on the side of the spindle 13, which penetrates the side wall of the spindle 13 and communicates with the second mounting groove 133; the electric screwdriver also includes a sliding sleeve 193 and a positioning bead 194; the sliding sleeve 193 is slidably connected to the outside of the spindle 13, and the sliding sleeve 193 is correspondingly provided on the outside of the positioning hole 134, and a storage groove 1931 is provided on the inner side of the sliding sleeve 193; the positioning bead 194 is movably disposed in the positioning hole 134, and the cross-sectional width of the positioning bead 194 is greater than the length of the positioning hole 134.

[0089] The movement trajectory of the positioning bead 194 along the straight line extending from the positioning hole 134 includes a fixed position and a movable position, with the fixed position located outside the movable position. When the positioning bead 194 is in the fixed position, it engages with the second positioning groove 141, and the inner wall of the sliding sleeve 193 closes the outer side of the positioning hole 134. When the positioning bead 194 is in the movable position, it engages with the storage groove 1931, and the outer side of the bit 14 closes the inner side of the positioning hole 134.

[0090] The bit 14 is inserted into the second mounting slot 133, which facilitates the replacement of different types of bit 14, thereby enabling the disassembly and assembly of different screws; the sliding sleeve 193 facilitates the quick disassembly and assembly of bit 14 and spindle 13, and improves the stability of the connection between bit 14 and spindle 13.

[0091] The electric screwdriver in this embodiment also includes a second limiting ring, a spring retainer 196, and an elastic element 195. The second limiting ring is located outside the spindle 13, below the longitudinal bearing assembly 192, and below the positioning hole 134. The spring retainer 196 is sleeved on the spindle 13, below the positioning hole 134. A sliding sleeve 193 is located between the spring retainer 196 and the second limiting ring, and the spring retainer 196 is used to limit the position of the sliding sleeve 193. The elastic element 195 is located between the second limiting ring and the top of the sliding sleeve 193, and the elastic element 195 elastically presses the sliding sleeve 193 into contact with the second limiting ring. Preferably, the second limiting ring in this embodiment is a retaining ring 135, but it can also be an annular structure integrated with the spindle 13.

[0092] The elastic element 195 elastically compresses the sliding sleeve 193 to contact the second limiting ring, so that the positioning bead 194 is kept in a fixed position, preventing the sliding sleeve 193 from loosening due to the vibration of the electric screwdriver during use.

[0093] Furthermore, a first positioning groove 136 is provided on the outer side of the spindle 13, and the elastic retaining spring 196 is engaged with the first positioning groove 136, which improves the stability of the connection between the elastic retaining spring 196 and the spindle 13 and prevents the elastic retaining spring 196 from falling off.

[0094] Working principle of the invention:

[0095] I. During the use of electric screwdrivers:

[0096] In this embodiment, the sensor body 15 has a deformation part 152 that is an elastic element. The deformation part 152 is equipped with a strain device, and the position of the deformation part 152 corresponds to the outer ring position of the main shaft 13.

[0097] The upper part of the sensor body 15 is fixedly connected to the output part of the motor 12 via the connecting flange 16.

[0098] 3. The lower part of the sensor body 15 is fixedly connected to the outer shell 11, and the strain device installed on the deformation part 152 can detect the torque difference between the upper and lower parts of the sensor.

[0099] 4. The motor 12 and the spindle 13 are connected and driven inside the sensor body 15. The rotational force of the motor 12 is transmitted to the upper part of the sensor body 15 through the connecting flange 16. Therefore, torque is generated between the upper part and the lower part of the sensor body 15 for detection.

[0100] The electric screwdriver includes a compact and simple housing 11, a spindle 13, and a sensor body 15, which are reasonably designed and easy to install and use.

[0101] II. When the user needs to install the screwdriver bit 14: First, push the sliding sleeve 193 upwards so that the storage groove 1931 on the inner side of the sliding sleeve 193 aligns with the positioning hole 134; second, take out the screwdriver bit 14 and insert it into the second mounting groove 133. During the insertion process, the side wall of the screwdriver bit 14 will press the positioning bead 194 into the storage groove 1931; then, after the screwdriver bit 14 is inserted into place, the second positioning groove 141 aligns with the positioning hole 134. Release the sliding sleeve 193, and the elastic element 195 will elastically drive the sliding sleeve 193 to return to its original position. The sliding sleeve 193 will press the positioning bead 194 to move along the extension direction of the positioning hole 134, so that the positioning bead 194 engages with the second positioning groove 141. Finally, the elastic element 195 elastically presses the sliding sleeve 193 to fit against the second limiting ring, and the positioning bead 194 engages with the second positioning groove 141. The screwdriver bit 14 is now installed.

[0102] When the user disassembles or replaces bit 14, the above steps can be repeated, and will not be elaborated here.

[0103] This completes the working process of the electric screwdriver with precise transmission in this preferred embodiment.

[0104] Furthermore, the main inventive point of this invention is the fixed connection structure of the sensor body 15; the working principle of the sensor body 15 and its wire connection structure in this embodiment are existing technologies and are mostly used in existing automation technologies, so they will not be described in detail here.

[0105] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A precision-driven electric screwdriver, characterized in that, include: shell; An electric motor is disposed inside the housing, and a rotating part is provided at the bottom end of the electric motor, and a drive shaft is provided on the rotating part; A spindle is disposed inside the housing, one end of which is connected to the drive shaft, and the other end is provided with a bit; as well as The sensor body has a hollow cylindrical structure, and a strain gauge is provided in the middle of the sensor body. The strain gauge is used to collect meridional torque data. A transmission assembly is provided between the top of the sensor and the rotating part. The top of the sensor body is connected to the rotating part through the transmission assembly. The sensor body is sleeved on the outer ring of the main shaft, and the bottom end of the sensor body is connected to the outer shell. The transmission assembly includes: A connecting flange, the bottom end of which is connected to the sensor body, and the top end of which is connected to the rotating part; and A steel ring is fitted around the outer ring of the connecting flange, and the outer ring of the steel ring is in contact with the inner wall of the outer shell. The steel ring can rotate relative to the upper plane of the sensor body. When the lower part of the sensor body is subjected to a horizontal force, the force will first act on the outer shell through the steel ring. A steel shaft is disposed between the outer ring of the connecting flange and the inner wall of the steel ring, and the axial extension direction of the steel shaft is parallel to the axial extension direction of the main shaft.

2. The precision-driven electric screwdriver according to claim 1, characterized in that, A first groove is provided on the outside of the connecting flange, and the steel shaft is received in the first groove. One side of the outer surface of the steel shaft is in contact with the inner wall of the steel ring.

3. The precision-driven electric screwdriver according to claim 2, characterized in that, The transmission assembly also includes a steel sheet disposed between the top of the connecting flange and the rotating part, and the bottom surface of the steel sheet defines the position of the top surface of the steel shaft.

4. The precision-driven electric screwdriver according to claim 1, characterized in that, The sensor body includes: A first connecting part is located at the top of the sensor body, and the first connecting part is connected to the connecting flange; A second connecting part is located at the bottom end of the sensor body, and the second connecting part is connected to the outer casing; and The deformation section is located in the middle of the sensor body, and the cross-sectional diameter of the deformation section is smaller than the cross-sectional diameter of the first connecting section and the cross-sectional diameter of the second connecting section. The deformation section is connected to a strain device on its outer side.

5. The precision-driven electric screwdriver according to claim 4, characterized in that, The first connecting part is provided with a plug-in slot; The connecting flange includes: A first fixing part is inserted into the insertion slot, and the first fixing part is connected to the first connecting part; and The second fixing part is located above the first connecting part, and the second fixing part is connected to the rotating part.

6. The precision-driven electric screwdriver according to claim 4, characterized in that, A first limiting ring is provided on the outer side of the main shaft; The second connecting portion is provided with a first fixing groove and a second fixing groove, the first fixing groove being located above the second fixing groove, and the cross-sectional diameter of the first fixing groove being less than or equal to the cross-sectional diameter of the second fixing groove; the electric screwdriver further includes: A horizontal bearing assembly, sleeved outside the main shaft and located above the first limiting ring, rotatably connects the top surface of the first limiting ring to the top wall of the first fixing groove; and A longitudinal bearing assembly is sleeved on the outside of the main shaft and located below the first limiting ring. The longitudinal bearing assembly rotatably connects the outer surface of the main shaft to the side wall of the second fixing groove.

7. The precision-driven electric screwdriver according to claim 6, characterized in that, The outer ring of the spindle is provided with a first groove, which is located below the longitudinal bearing assembly. The first groove is connected to a retaining ring, which is used to support the longitudinal bearing assembly.

8. The precision-driven electric screwdriver according to claim 4, characterized in that, The outer casing includes: The main housing is a hollow cylindrical structure with an opening at its bottom. The motor is located inside the main housing, and the outer side of the second connecting part is connected to the main housing. A front cover is connected to the main housing and is used to close the opening. The bottom end of the sensor body is connected to the front cover.

Images