Quick-change chuck, electric tool and working head connecting method

Abstract

The invention discloses a quick-change chuck which is used for being detachably connected with and driving a working head with an inserting part, the quick-change chuck comprises an inner shaft sleeve, an outer shaft sleeve and at least one cutting blade made of a material with the hardness higher than that of the inserting part, the inner shaft sleeve is provided with at least one guide channel extending inwards from the outer circumferential surface of the inner shaft sleeve to a mounting cavity, and the outer shaft sleeve is provided with at least one guide channel extending inwards from the outer circumferential surface of the inner shaft sleeve to the mounting cavity. The cutting blade is mounted in the guide channel in a locatable manner and is provided with a cutting part which protrudes into the mounting cavity through the guide channel; when the inserting part of the working head is inserted into the mounting cavity in the axial direction, the peripheral surface of the inserting part is cut by the cutting part of the cutting piece, so that a groove matched with the cutting part in shape is formed in the inserting part. In this way, circumferential locking is achieved through meshing of the groove and the cutting part, and torque is transmitted from the inner shaft sleeve to the working head through the cutting piece.

Description

Technical Field

[0001] This invention relates to the field of power tools, specifically to a quick-change chuck, a power tool, and a method for connecting a working head. Background Technology

[0002] In grinding, cutting, and polishing operations, it is often necessary to change different working heads (such as grinding heads, milling cutters, drill bits, etc.). Traditional chuck connection methods typically employ threaded locking, spring collets, or specific grooves for ball bearing engagement. These methods have several drawbacks: threaded connections are slow to install and remove and are prone to loosening due to vibration; spring collets have stringent requirements for the dimensional tolerances of the working head shank and poor compatibility; while using pre-set grooves for ball bearing engagement requires the working head to have precisely machined grooves beforehand, increasing manufacturing costs, and requiring precise angle alignment during installation, making operation inconvenient.

[0003] Therefore, the industry needs a chuck connection solution that can achieve quick, tool-free assembly and disassembly, provide robust torque transmission, and has low requirements for pre-processing of the working head. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a quick-change chuck to solve the problem of low assembly and disassembly efficiency in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: According to one aspect of the present invention, a quick-change chuck is provided for detachably connecting and driving a working head having a plug-in portion. The quick-change chuck includes an inner bushing, at least one cutting blade, and an outer bushing. The inner bushing has an axial mounting cavity for receiving the plug-in portion. The cutting blade is made of a material with a hardness higher than that of the plug-in portion. The outer bushing is sleeved outside the inner bushing. The inner bushing has at least one guide channel extending inward from its outer circumferential surface to the mounting cavity. The cutting blade is positionably mounted in the guide channel and has a cutting portion protruding into the mounting cavity through the guide channel. When the plug-in portion of the working head is axially inserted into the mounting cavity, the outer circumferential surface of the plug-in portion is cut by the cutting portion of the cutting blade, thereby forming a groove on the plug-in portion that matches the shape of the cutting portion in the field, realizing circumferential locking and torque transmission between the plug-in portion and the cutting blade.

[0006] Preferably, the guide channel includes an axial positioning groove formed on the outer circumferential surface of the inner bushing, the positioning groove communicating with the mounting cavity on the radially inner side to form a path for the cutting part of the cutting blade to extend into.

[0007] Preferably, the cutting blade is offset when installed in the positioning groove, so that its cross-section abuts against the wall of the guide channel in the circumferential direction, thereby constraining its circumferential position and ensuring that the cutting part reliably protrudes into the mounting cavity.

[0008] Preferably, the cutting blade is a long strip of metal with a cutting portion formed at one end; multiple cutting blades are spaced apart circumferentially along the inner bushing, and their cutting portions together form a ring-shaped cutting array within the mounting cavity.

[0009] Preferably, the axial length of the cutting portion of the cutting blade extending into the mounting cavity is at least half the axial depth of the mounting cavity to ensure sufficient engagement length and connection stability.

[0010] Preferably, the inner wall of the outer bushing abuts against the outer side of the portion of the cutting blade located within the guide channel, thereby constraining the cutting blade radially and preventing it from dislodging from the guide channel during operation.

[0011] Preferably, the device further includes an elastic damping element. The outer shaft sleeve is provided with an annular receiving portion for accommodating the elastic damping element, the elastic damping element having a central hole with a diameter smaller than that of the insertion portion, so that a radial interference fit is generated when the insertion portion passes through, providing axial damping and preventing accidental dislodgement.

[0012] Preferably, the mounting cavity of the inner bushing has a tapered guide slope at its inlet end to guide the insertion of the connector smoothly. The mounting cavity has a stop portion at its bottom to limit over-insertion of the connector.

[0013] Preferably, a circumferential limiting structure is provided between the outer bushing and the inner bushing, including an annular boss located on the lower part of the outer periphery of the inner bushing and an annular groove located on the lower part of the inner wall of the outer bushing that is adapted to the annular boss.

[0014] According to another aspect of the present invention, a working head connection method using the above-described quick-change chuck is provided, comprising the steps of: aligning the insertion portion of the working head and axially inserting it into the mounting cavity of the quick-change chuck locking device; during the insertion process, using the cutting portion of the cutting blade to cut a groove on the outer peripheral surface of the insertion portion in the field; when the insertion portion is inserted to a predetermined depth, circumferential locking is achieved through the engagement of the groove with the cutting portion, and torque is transmitted from the inner bushing to the working head through the cutting blade.

[0015] According to another aspect of the present invention, a power tool employing the above-described quick-change chuck is provided. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional schematic diagram of the quick-change chuck in this application.

[0018] Figure 2 This is a schematic diagram of the explosion of the quick-change chuck in this application.

[0019] Figure 3 This is a longitudinal cross-sectional view of the quick-change chuck in this application.

[0020] Figure 4 This is a schematic cross-sectional view of the quick-change chuck in this application.

[0021] Figure 5 This is a schematic diagram of the inner bushing structure of this application. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0023] Reference Figures 1 to 5 As shown, the quick-change chuck provided in this application includes an inner bushing 30, a cutting blade 50, an outer bushing 20, and an elastic damping element 40. Each component is sequentially fitted along the axial direction to form a compact and functionally coordinated whole. During the insertion process of the working head 10, such as a grinding head, the cutting blade 50 cuts a groove in the insertion part 101 of the working head 10, so that the cutting blade 50 and the insertion part 101 of the working head 10 are tightly fitted. In this way, the inner bushing 30 can transmit torque to the working head 10. Furthermore, the elastic damping element 40 provides damping, so that the grinding head will not fall out during use.

[0024] Overall, this quick-change chuck does not require additional tools during assembly, and the working head can be changed quickly.

[0025] It should be noted that the cutting blade 50 has a higher hardness than the insertion part 101 of the working head 10, so as to ensure that the cutting blade 50 can cut grooves on the insertion part 101.

[0026] In one embodiment, the cutting blade 50 is a long strip of hard metal (such as high-speed steel or cemented carbide).

[0027] Specifically, refer to Figures 2 to 5As shown, the inner bushing 30 is generally cylindrical, with an axially penetrating cylindrical mounting cavity 302 in the center for accommodating the insertion part 101 of the working head 10; the outer circumferential surface is provided with a plurality of positioning grooves 301 at intervals along the circumferential direction, the positioning grooves 301 extending axially along the inner bushing 30 to provide mounting positioning for the cutting blade 50.

[0028] Reference Figure 4 As shown, multiple (e.g., three) positioning grooves 301 are arranged circumferentially along the outer circumferential surface of the inner bushing 30. The positioning grooves 301 extend axially along the inner bushing 30 and at least partially communicate with the mounting cavity 302 in the radial direction to form a guide channel 310. That is, each positioning groove 301 communicates with the mounting part 302 through a channel on the radial inner side, and the through structure together constitutes a guide channel 310.

[0029] The inner end of the guide channel 310 communicates with the inner cavity of the mounting cavity 302, providing an insertion path for the cutting part 501 of the cutting blade 50, i.e.: The cutting blade 50 is installed in the positioning groove 301, with at least a portion passing through the guide channel 310 and protruding from the inner wall of the guide channel 310, extending into the mounting cavity 302 to cooperate with the insertion part 101 of the working head 10.

[0030] Furthermore, refer to Figure 5 As shown, the cutting blade 50 is installed in the positioning groove 301 in an offset state. The cross-section of the cutting blade 50 abuts against the wall of the guide channel 310 in the circumferential direction, so that the cutting part 501 of the cutting blade 50 extends into the mounting cavity 302 to cooperate with the insertion part 101 of the working head 10.

[0031] Thus, the cutting blades 50 are embedded one-to-one into the positioning grooves 301 of the inner bushing 30 with their cutting portions 501 facing the central axis of the mounting portion 302. After installation, the cutting blades 50 are in a certain offset state within the positioning grooves 301, with their sides abutting against the wall of the guide channel 310 (i.e., one side wall of the positioning groove 301), thereby restricting circumferential movement. At this time, the cutting portions 501 of the cutting blades 50 pass through the guide channel 310 and reliably protrude into the inner cavity of the mounting portion 302. The cutting portions 501 of multiple cutting blades 50 are evenly distributed circumferentially within the mounting portion 302, forming a ring-shaped cutting array. In addition, a tapered guide slope 303 is provided at the port of the mounting cavity 302 for the smooth insertion of the insertion portion 101 of the working head 10; a stop portion 305 is provided at the bottom of the inner cavity of the mounting cavity 302, and when the insertion portion 101 is fully inserted, the bottom end of the insertion portion 101 abuts against the stop portion 305, restricting excessive axial insertion. The lower outer periphery of the inner bushing 30 is also provided with an annular boss 304, which is used to cooperate with the outer bushing 20 to achieve circumferential positioning.

[0032] Furthermore, the cutting blade 50 is preferably a long strip of metal, the number of which is the same as that of the positioning groove 301 and they are embedded in the positioning groove 301 in a one-to-one correspondence. The length of the cutting part 501 that extends into the mounting cavity 302 to cooperate with the insertion part 101 of the working head 10 is at least half the depth of the mounting cavity 302 to ensure that the subsequent forming engagement groove has sufficient length and to ensure a stable connection.

[0033] Reference Figure 3 As shown, one end of the cutting blade 50 forms a cutting portion 501 that protrudes towards the central axis of the mounting cavity 302, and its extension direction is parallel to the axis of the guide channel 310 of the positioning groove 301. When the cutting blade 50 is embedded in the positioning groove 301, the cutting portion 501 protrudes into the inner cavity of the mounting cavity 302 through the guide channel 310, and the cutting portions 501 of each cutting blade 50 are evenly distributed in the circumferential direction, forming a ring-shaped cutting array together.

[0034] Reference Figure 2 , Figure 3 As shown, the outer bushing 20 is fitted outside the inner bushing 30, and its inner wall abuts against the outer side of the cutting blade 50 to provide radial restraint.

[0035] The outer bushing 20 has an axially penetrating through hole, which is coaxially arranged with the mounting cavity 302 of the inner bushing 30, together forming the insertion channel of the insertion part 101. An elastic damping element 40 is accommodated between the upper part of the inner wall of the outer bushing 20 and the inner bushing; the lower part of the inner wall of the outer bushing 20 has an annular groove 202, which is adapted to the annular boss 304 of the inner bushing 30. The annular boss 304 is embedded in the annular groove 202 to achieve circumferential positioning of the inner bushing 30 and the outer bushing 20.

[0036] Reference Figure 2 , Figure 3 As shown, the elastic damping element 40 is preferably an O-ring or similar elastic sealing ring made of silicone, which is embedded between the outer bushing 20 and the inner bushing. Its bottom abuts against the top wall of the inner bushing 30, and the central hole 401 is sleeved on the outer periphery of the insertion part 101. The inner diameter of the elastic damping element 40 is smaller than the diameter of the insertion part 101, forming an interference fit.

[0037] The insertion part 101 can extend axially into the mounting cavity 302 of the inner bushing 30. The insertion part 101 passes through the through hole of the outer bushing 20 and the center hole 401 of the elastic damping member 40 in sequence before extending into the mounting cavity 302.

[0038] The working principle and assembly / disassembly process of this quick-change chuck are as follows: During assembly: The operator aligns the cylindrical insertion part 101 of the working head 10 with the through hole of the outer bushing 20 and inserts it.

[0039] The insertion part 101 first passes through the center hole 401 of the elastic damping member 40. Due to its large diameter, it will slightly open the elastic damping member 40 and generate a certain frictional damping.

[0040] Next, the insertion part 101 smoothly enters the mounting part 302 of the inner bushing 30 under the guidance of the guide ramp 303. As insertion continues, the end or side of the insertion part 101 begins to contact the cutting part 501 of the cutting blade 50. The applied axial thrust forces the high-hardness cutting part 501 to cut into the relatively soft surface material of the insertion part 101, like a miniature planer or broach, cutting a groove on the cylindrical surface of the insertion part 101 that perfectly matches the cross-sectional shape of the cutting part 501.

[0041] Insertion stops when the bottom end of the insertion part 101 contacts the stop part 305. At this time, the cutting part 501 of the cutting blade 50 is fully embedded in the groove it cuts on the insertion part 101, forming a tight mechanical interlock. The clamping force of the elastic damping element 40 provides additional anti-loosening protection. When the drive device rotates the inner bushing 30, the torque is transmitted to the cutting blade 50 through the side wall of the positioning groove 301, and then reliably transmitted to the working head 10 through the meshing surface of the cutting blade 50 and the groove.

[0042] During disassembly: The operator pulls the working head 10 outwards axially. The pulling force first overcomes the friction of the elastic damping element 40, and then the insertion part 101 slides axially out of the groove formed by the cutting blade 50, disengaging the mechanical engagement. The entire pull-out process is smooth until the working head 10 is completely disengaged. Only the insertion part 101 of the working head 10 leaves a permanent groove in the device, while all internal components of the chuck (cutting blade, elastic damping element, etc.) can be reused for the next installation.

[0043] Furthermore, according to another aspect of the present invention, a working head connection method using the above-described quick-change chuck is provided, comprising the steps of: aligning the insertion portion of the working head and axially inserting it into the mounting cavity of the quick-change chuck locking device; during the insertion process, using the cutting portion of the cutting blade to cut a groove on the outer peripheral surface of the insertion portion in the field; when the insertion portion is inserted to a predetermined depth, circumferential locking is achieved through the engagement of the groove with the cutting portion, and torque is transmitted from the inner bushing to the working head through the cutting blade.

[0044] According to another aspect of the present invention, a power tool employing the above-described quick-change chuck is provided.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A quick-change chuck for detachably connecting to and driving a working head having a plug-in portion, characterized in that, include: The inner bushing has a mounting cavity for accommodating the insertion portion; At least one cutting blade is made of a material with a hardness higher than that of the insertion portion; And an outer bushing, fitted onto the outside of the inner bushing; The inner shaft sleeve is provided with at least one guide channel extending inward from its outer circumference to the mounting cavity. The cutting blade is positionably mounted in the guide channel and has a cutting portion protruding into the mounting cavity through the guide channel. When the insertion portion of the working head is inserted axially into the mounting cavity, the outer peripheral surface of the insertion portion is cut by the cutting portion of the cutting blade to form a groove on the insertion portion that matches the shape of the cutting portion.

2. The quick-change chuck according to claim 1, characterized in that, The guide channel includes a positioning groove formed on the outer circumferential surface of the inner bushing. The positioning groove communicates with the mounting cavity on the radially inner side, forming a path for the cutting part of the cutting blade to extend into.

3. The quick-change chuck according to claim 2, characterized in that, When the cutting blade is installed in the positioning groove, it is in an offset state, such that the cross-section of the cutting blade abuts against the wall of the guide channel in the circumferential direction, thereby constraining the circumferential position of the cutting blade.

4. The quick-change chuck according to claim 2 or 3, characterized in that, The cutting blade is elongated and the cutting portion is formed on one side; multiple cutting blades are arranged circumferentially along the inner bushing, and their cutting portions together form a ring-shaped cutting array within the mounting cavity.

5. The quick-change chuck according to claim 4, characterized in that, The cutting portion of the cutting blade extends along the axial direction of the inner bushing, and the axial length of the cutting portion extending into the mounting cavity is at least half of the axial depth of the mounting cavity.

6. The quick-change chuck according to claim 1, characterized in that, The inner wall of the outer bushing abuts against the outer side of the portion of the cutting blade located within the guide channel to constrain the cutting blade radially.

7. The quick-change chuck according to claim 1, characterized in that, It also includes an elastic damping element located between the outer bushing and the inner bushing, the elastic damping element having a central hole with a diameter smaller than that of the insertion portion.

8. The quick-change chuck according to claim 1, characterized in that, The mounting cavity of the inner bushing has a tapered guide slope at its inlet end.

9. A method for connecting a working head, employing a quick-change chuck as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Align the connector of the working head with and insert it axially into the mounting cavity of the quick-change chuck; During the insertion process, the cutting part of the cutting blade is used to cut a groove on the outer peripheral surface of the insertion part in the field. When the insertion part is inserted to a predetermined depth, circumferential locking is achieved through the engagement of the groove with the cutting part, and torque is transmitted from the inner bushing to the working head through the cutting blade.

10. A power tool, characterized in that, Includes the quick-change chuck as described in any one of claims 1 to 8.

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