CN112388576B

CN112388576B - A quick clamping device and a multifunctional machine tool using the same

Info

Publication number: CN112388576B
Application number: CN202011596278.1A
Authority: CN
Inventors: 陆传洋; 张成龙
Original assignee: Nanjing Jiuchi Electromechanical Industry Co ltd
Current assignee: Nanjing Jiuchi Electromechanical Industry Co ltd
Priority date: 2020-10-15
Filing date: 2020-12-29
Publication date: 2025-02-11
Anticipated expiration: 2040-12-29
Also published as: CN112388576A; WO2022077899A1; CN214519996U; CN112223220A

Abstract

The invention relates to a cutter quick clamping device of a handheld electric tool, and belongs to the technical field of electric tools. The device comprises a vertical hollow output shaft, a pull rod with a stretching cone at the lower end, a sliding groove which forms a vertical moving pair with a hinge pin at the middle part of the pull rod, the hinge pin is hinged at the upper parts of a left chuck and a right chuck which are matched with the stretching cone at the two sides of the pull rod, the inner sides of the lower ends of the left chuck and the right chuck are matched with the stretching cone, the upper ends of the left chuck and the right chuck are in contact with a small spring sleeved on the pull rod, the upper end of the small spring is in contact with a pressing device for pressing the pull rod, the pressing device is also in contact with the upper end of a large spring, and the lower end of the large spring is limited on the output shaft. The invention is completely released and no clamping stagnation can occur, and in the tensioning process, the lifting of the pull rod by the large spring and the pressing of the left chuck and the right chuck by the small spring are relatively acted, so that the expanding cone has strong tensioning effect, and the clamping of the cutter is very reliable.

Description

Quick clamping device and multifunctional tool machine adopting same

Technical Field

The invention relates to a cutter quick clamping device of a handheld electric tool, and also relates to a multifunctional machine tool adopting the device, belonging to the technical field of electric tools.

Background

The output shaft of a multifunctional machine tool swings about its own axis, driving a working head (including a straight saw blade, a circular saw blade, a triangular sanding plate and a shovel blade) mounted at the shaft end to move therewith, and can perform various operations such as sawing, cutting, grinding, scraping and the like, is a commonly used hand-held electric tool, the typical structure of which is disclosed in chinese patent application No. 201380021580.6, the machine having a housing extending generally along the longitudinal axis, the housing having a grip area arranged for being gripped and guided by a single hand of a user of the machine tool, the machine tool comprising an electric drive unit and tool equipment generally accommodated in the housing, the tool equipment being generally mechanically decoupled from the housing. The housing has a center of gravity which, as a function of the length of the housing, is arranged along the longitudinal axis in a section which extends from the geometric center of the housing to the rear.

To the applicant's knowledge, quick clamping devices for tools such as saw blades, grinding heads, etc. are critical to the usability of the multi-function machine tools, since various types or specifications of tools often need to be replaced as appropriate during use of the existing multi-function machine tools.

In search, the chinese patent application 201480043554.8 discloses a manually guided tool machine with a tool receiving device that can be moved about a drive shaft, in particular can be moved in an oscillating manner, in order to hold the tool device on the tool machine. The tool receiving device has at least one tensioning device, at least one holding device and at least one locking device. The retaining means is movable from at least one first open position to at least one second closed position. Furthermore, the holding means may preferably be acted upon by the tensioning means in a closing direction from the first open position towards the second closed position. The locking means is movable between at least one first locked position and at least one second unlocked position. In this case, the movement of the holding device can be prevented by the locking device in at least one locking position. The force exerted on the locking means by the tool means, either indirectly or directly, moves the locking means from a locked position to an unlocked position. The tool receiving device with tensioning, holding and locking in this solution allows a quick and simple installation of the tool in the tool machine, but it is obvious that the manufacturing and assembly process is not good enough, in particular the holding device thereof, the geometry is complex and the machining difficulties are great.

In addition, chinese patent documents having application numbers 2015110120755. X and 201610221396.1 respectively disclose a multifunctional tool quick-change structure capable of performing various operations such as cutting and sanding, and a quick-change multifunctional saw structure, and the technical schemes of the two patents all adopt elastic clamping head structures to realize quick clamping of a cutter, so that after the use, the elastic clamping heads are inevitably damaged due to fatigue caused by repeated elastic deformation and recovery, and the service life is limited.

Disclosure of Invention

The invention aims to provide a rapid cutter clamping device which is simple in structure, good in manufacturing process and capable of avoiding fatigue damage and provides a multifunctional tool machine adopting the device.

In order to achieve the aim, the quick cutter clamping device comprises a swinging and rotating vertical hollow output shaft fixedly connected with an output shaft base and a lifting pull rod positioned in the output shaft, wherein the lower end of the pull rod is provided with a supporting expansion cone, the middle part of the pull rod is provided with a sliding groove which forms a vertical moving pair with a hinge pin, the hinge pin is hinged with the upper parts of a left chuck and a right chuck which are combined with the two sides of the pull rod, the lower ends of the left chuck and the right chuck extend out of a central hole of the output shaft base, the inner sides of the lower ends of the left chuck and the right chuck are matched with the supporting expansion cone, and the outer sides of the lower ends of the left chuck and the right chuck are matched with a mounting hole of a cutter to be clamped;

The lower pressing device is provided with an upper limit position and a lower limit position, when the lower limit position is reached, the downward travel of the pull rod is larger than that of the left chuck and the right chuck, so that the lower ends of the left chuck and the right chuck are in a releasing state separated from the expanding cone, and when the upper limit position is reached, the pull rod is elastically lifted, so that the lower ends of the left chuck and the right chuck are in a tensioning state expanded by the expanding cone.

The left clamping head and the right clamping head are in a tensioning state that the lower ends of the left clamping head and the right clamping head are propped by a large spring with the elastic coefficient larger than that of the small spring after being lifted by the large spring, and the lower ends of the left clamping head and the right clamping head are propped by a stretching cone when the pull rod is in an upper limit position.

The invention realizes the quick disassembly and assembly of the cutter by utilizing the downward movement, the release and the upward movement and the tensioning of the lower ends of the left chuck and the right chuck, the lower ends are sensitive to open and close because the upper ends of the left chuck and the right chuck are hinged, and the sliding groove structure of the pull rod realizes the over-travel downward movement of the pull rod relative to the left chuck and the right chuck in the release process, so that the release is complete and the clamping stagnation can not occur, and the lifting of the pull rod by the big spring and the downward pressing of the small spring relative to the left chuck and the right chuck in the tensioning process can lead the expanding cone to generate a powerful tensioning effect, so that the clamping of the cutter is very reliable.

The multifunctional tool machine adopting the rapid cutter clamping device comprises a motor arranged in the middle and a shell with a transmission box arranged at the front, wherein the motor is in transmission connection with an output shaft through a swing transmission mechanism, the transmission box consists of a vertical part for supporting the output shaft and a horizontal part for arranging the motor and the transmission mechanism, and the rapid cutter clamping device is arranged on the vertical part.

Drawings

The invention is further described below with reference to the accompanying drawings.

Fig. 1 is a schematic perspective view of a multifunctional machine tool according to the present invention.

Fig. 2 is a schematic top view of the embodiment of fig. 1 in a locked state.

Fig. 3 is a schematic view of the cross-sectional B-B structure of fig. 2.

Fig. 4 is a schematic top view of the embodiment of fig. 1 in a released state.

Fig. 5 is a schematic view of the cross-sectional B-B structure of fig. 4.

Fig. 6 is a schematic perspective exploded view of the portion of the tool quick clamp of fig. 1.

In the figure, a screw 1, a rotary handle 2, a retainer ring 3, a rotary handle gland 4, a rotary seat 5, a pressing block 6, a transmission box 7, a retainer ring 8, an upper bearing 9, an output shaft 10, a framework oil seal 12, a needle bearing 13, a nut 14, a spring pad 15, an upper gasket 16, a large spring 17, a small spring 18, a lower gasket 19, a pull rod 20, a hinge pin 21, a left clamping head 22, a right clamping head 23, a saw blade 24, a shifting fork 25, a spherical bearing 27, a bearing seat 31, a front bearing 32, an eccentric shaft 33, a motor stator assembly 34, a motor rotor assembly 35, a rear bracket 36 and a shell 39 are shown.

Detailed Description

Example 1

The multifunctional machine tool of the embodiment is shown in fig. 1 to 6, and is similar to the basic structure of the prior art, wherein a battery pack is arranged at the rear end of a shell 39, a motor is arranged in the middle, a transmission case 7 is arranged at the front part, and the motor is in transmission connection with an output shaft through a swing transmission mechanism. The transmission case 7 is L-shaped and consists of a vertical part for supporting the output shaft 10 and the cutter quick clamping device and a horizontal part for arranging a motor and a transmission mechanism, and the tubular vertical part supports the hollow output shaft 10 through an upper bearing 9 and a lower needle bearing 13. The swing transmission mechanism is composed of the output end of the motor rotor and the fork opening of the fork 25 sleeved on the output shaft 10 through the spherical bearing 27 at the front end of the eccentric shaft 33.

The cutter quick clamping device is specifically composed of a swingable and rotatable vertical hollow output shaft 10 fixedly connected with an output shaft base 11 and a liftable pull rod 20 positioned in the output shaft 10. The output shaft base 11 is tightly fitted to the lower end of the output shaft 10, and has a circumferential positioning projection D on the lower surface thereof, which is fitted to the saw blade 24 as a tool to be clamped.

The lower end of the pull rod 20 is provided with a supporting expansion cone 20-1, and the middle part is provided with a chute 20-2 which forms a vertical moving pair with a hinge pin 21. The hinge pin 21 is hinged to the upper parts of the left chuck 22 and the right chuck 23 which are engaged to both sides of the pull rod. The lower parts of the left chuck 22 and the right chuck 23 are radially contracted so that the lower ends extend out of the central hole of the output shaft base 11 and form a lower limit step surface T in the middle. The inner sides of the lower ends of the left clamping head 22 and the right clamping head 23 are matched with the expanding cone 20-1, and the outer sides of the lower ends are provided with necks matched with the mounting holes of the saw blade 24 and stop eaves Z.

The upper ends of the left clamping head 22 and the right clamping head 23 are abutted with the small spring 18 sleeved on the pull rod 20 through the lower gasket 19, and the upper ends of the small springs 18 are abutted with the pressing device for pressing the pull rod 20 through the upper gasket 16. The upper gasket 16 is sleeved on the expanding shoulder of the pull rod 20 and is fixedly connected with the pull rod 20 through the nut 14 and the elastic pad 15 screwed on the upper end of the pull rod 20. The pressing device is also in contact with the upper end of the large spring 17 through the upper gasket 16, and the lower end of the large spring 17 is limited on the diameter-reducing step of the output shaft 10.

Specifically, the pressing device comprises a pressing block 6 sleeved on the flat section at the upper end of the pull rod 20 to form mutual circumferential constraint, an axial end face cam pair is formed by the upper end curved surface of the pressing block 6 and the lower end curved surface of the rotating seat 5, the outer circle of the upper section of the rotating seat 5 is in sliding fit with the upper through hole of the rotary handle gland 4, and the diameter-expanding ring in the middle is axially constrained on the lower end face of the upper through hole of the rotary handle gland 4. The rotary handle gland 4 is tightly arranged at the upper part of the vertical part of the transmission case 7. In addition, the upper outer circle of the rotary seat 5 is fixedly connected with the rotary handle 2 with two set angular limit positions through the hanging screw 1, so that the rotary handle 2 can be pulled to drive the rotary seat 5 to rotate, and then the pressing block 6 can simultaneously axially press the pull rod 20, the large spring 17 and the small spring 18 through the upper gasket 16 which is reasonably arranged through the end face cam pair.

The two angular limit positions of the rotary handle 2 respectively correspond to the upper limit position and the lower limit position of the pressing device. When the screwing handle 2 makes the pressing device at the lower limit position through the end face cam pair, the pull rod 20, the left clamp head 22 and the right clamp head 23 are downwards moved by overcoming the acting force of the large spring 17 and the small spring 18, and the lower limit step surface T at the middle part of the left clamp head 22 and the right clamp head 23 is firstly limited by the upper end face of the output shaft base 11, so that the downward movement stroke of the pull rod 20 is larger than that of the left clamp head and the right clamp head, the left clamp head 22 and the right clamp head 23 are in a release state that the lower ends are separated from the expansion cone 20-1 (see fig. 4 and 5), and in the process, the constraint of the chute 20-2 on the hinge pin 21 ensures the stable downward movement of the left clamp head 22 and the right clamp head 23, and the motion interference is avoided.

When the end cam pair releases the downward pressure due to the return of the screwing handle 2, the downward pressing device is at the upper limit position under the rebound and return actions of the large spring and the small spring, the pull rod 20 is lifted by the large spring 17 with the elastic coefficient larger than that of the small spring 18, the left clamping head 22 and the right clamping head 23 are in a tensioning state (see fig. 2 and 3) with the lower ends being supported by the supporting expansion cone 20-1, at the moment, the small spring 18 still has a certain downward pressing action on the left clamping head 22 and the right clamping head 23, and the upward pulling action of the pull rod 20 is complemented with each other, so that the fit supporting with the supporting expansion cone 20-1 is enhanced, and the stop eave Z is added, so that the reliable installation of the saw blade 24 is ensured.

In addition to the embodiments described above, other embodiments of the invention are possible. For example, the pressing device may be configured by a knob that rotates around a horizontal axis. All technical schemes formed by equivalent substitution or equivalent transformation fall within the protection scope of the invention.

Claims

1. A quick clamping device for a cutter comprises a swinging and rotating vertical hollow output shaft fixedly connected with an output shaft base and a lifting pull rod positioned in the output shaft, and is characterized in that the lower end of the pull rod is provided with a supporting expansion cone, the middle part of the pull rod is provided with a chute which forms a vertical moving pair with a hinge pin, the hinge pin is hinged on the upper parts of a left chuck and a right chuck which are matched with the two sides of the pull rod, the lower ends of the left chuck and the right chuck extend out of a central hole of the output shaft base, the inner sides of the lower ends of the left chuck and the right chuck are matched with the supporting expansion cone, and the outer sides of the lower ends of the left chuck and the right chuck are matched with a mounting hole of the cutter to be clamped;

the lower pressing device is provided with an upper limit position and a lower limit position, when the lower limit position is reached, the downward travel of the pull rod is larger than that of the left chuck and the right chuck, so that the lower ends of the left chuck and the right chuck are in a releasing state which is separated from the expanding cone, and when the upper limit position is reached, the pull rod is elastically lifted, so that the lower ends of the left chuck and the right chuck are in a tensioning state which is expanded by the expanding cone;

The upper ends of the left clamping head and the right clamping head are abutted against a small spring sleeved on the pull rod, the upper ends of the small springs are abutted against a pressing device for pressing the pull rod, the pressing device is abutted against the upper ends of large springs, the lower ends of the large springs are limited on the output shaft, and when the left clamping head and the right clamping head are in an upper limit position, the pull rod is lifted by the large springs with the elastic coefficient larger than that of the small springs, and then the left clamping head and the right clamping head are in a tensioning state with the lower ends being propped by the stretching cone.

2. The rapid clamping device for a cutter according to claim 1, wherein the upper ends of the left clamping head and the right clamping head are abutted against a small spring sleeved on the pull rod through a lower gasket, and the upper ends of the small springs are abutted against the pressing device through an upper gasket.

3. The rapid clamping device for the cutter according to claim 2, wherein the upper gasket is sleeved on the expanding shoulder of the pull rod and fixedly connected with the pull rod through a fastener screwed at the upper end of the pull rod.

4. The rapid cutter clamping device according to claim 3, wherein the pressing device is abutted against the upper end of the large spring through the upper gasket, and the lower end of the large spring is limited on the diameter-reducing step of the output shaft.

5. The rapid clamping device for a cutter according to claim 4, wherein the pressing device comprises a pressing block sleeved at the upper end of the pull rod to form mutual circumferential constraint, and an axial end face cam pair is formed by an upper end curved surface of the pressing block and a lower end curved surface of the rotating seat.

6. The quick cutter clamping device according to claim 5 is characterized in that an outer circle of the upper section of the rotating seat is in sliding fit with an upper through hole of a rotary handle gland, a diameter-expanding ring in the middle is axially restrained on the lower end face of the upper through hole of the rotary handle gland, the rotary handle gland is tightly mounted on the upper portion of the vertical portion of the transmission case, and the outer circle of the upper section of the rotating seat is fixedly connected with the rotary handle through a fastener.

7. A multifunctional machine tool comprises a motor arranged in the middle and a shell with a transmission box arranged at the front, wherein the motor is in transmission connection with an output shaft through a swing transmission mechanism, the transmission box consists of a vertical part for supporting the output shaft and a horizontal part for arranging the motor and the transmission mechanism, and the multifunctional machine tool is characterized in that the vertical part is provided with the rapid cutter clamping device according to any one of claims 1 to 6.