A multifunctional electric tool

Abstract

The present invention relates to a multifunctional electric tool, belonging to the technical field of electric tools. The tool comprises a tool driving mechanism that can move around the axis of an output shaft, and the tool driving mechanism contains at least one hanging device, a clamping device and a locking device; the hanging device can apply a tensioning force to the clamping device, the clamping device has an open position and a closed position, and the locking device has an unlocking position and a locking position; the force applied by the tool head on the locking device causes the locking device to move from the locking position to the unlocking position; the locking device releases the tensioning force applied by the hanging device to the clamping device by locking the hanging device at at least one locking position. After adopting the present invention, while having the advantage that the tool head can be installed with one hand by pressing down the locking device, the instability after being disturbed is completely eliminated, and the clamping device is more stable and reliable whether it is opened and clamped, closed and released, or the position conversion.

Description

Technical Field

[0001] The invention relates to a handheld electric tool, in particular to a multifunctional electric tool, belonging to the technical field of electric tools. Background Art

[0002] Among the existing electric tools, there is a type that requires frequent replacement of tool heads according to the working conditions. The most representative of these are the multifunctional electric tools disclosed in Chinese patent documents with application numbers 201210332520.3 and 201380021580.6. The output shaft of the tool swings around its own axis, driving the working head (including straight saw blades, circular saw blades, triangular sanding discs and shovel-shaped scrapers) installed at the end of the shaft to move accordingly, so that multiple operations such as sawing, cutting, grinding and scraping can be achieved.

[0003] In order to meet the needs of quick replacement of tool heads of various types or specifications such as knives during use, the quick-change device of the tool head has been continuously improved. Chinese patent documents with application numbers 201480043554.8, 201510120755.X, and 201610221396.1 respectively disclose different quick-change structure technical solutions. However, these technical solutions do not break through the fact that both hands are required to operate when disassembling and installing the tool head, and therefore fail to bring the greatest convenience to the user.

[0004] A search shows that a Chinese patent with application number 201480043554.8 discloses a machine tool having a tool receiving device that can move around a drive shaft, wherein the tool receiving device is designed to hold the tool device on the machine tool so that the drive shaft is basically consistent with the tool rotation axis, wherein the tool receiving device has at least one tensioning device, at least one holding device and at least one locking device, wherein the holding device can move from at least one first, open position to at least one second, closed position, wherein the holding device can also be subjected to tensioning force by the tensioning device, wherein the locking device can move between at least one first, locked position and at least one second, unlocked position, wherein the locking device is designed to cooperate with the holding device, wherein the movement of the holding device can be prevented in at least one locked position by the locking device, and wherein the locking device is configured so that the force indirectly or directly applied to the locking device by the tool device causes the locking device to move from one of the multiple locked positions to one of the multiple unlocked positions. The term "synergistic effect" is defined in paragraph

[0017] of the specification as: the movement of the retaining device can be indirectly or directly affected by the locking device. The technical solution innovates a unique structure of quick clamping to achieve the so-called "one touch" tool head installation in the industry - that is, as long as the locking device is pressed down, the tool head can be installed with one hand, so the tool device can be installed in the machine particularly quickly and easily.

[0005] However, analysis shows that this technical solution actually relies on the principle of the spring bistable mechanism under the action of tensioning force. It is not difficult to verify through experiments that when only the technical solution of the independent claim of the patent is adopted, since the position where the retaining device is blocked from moving by the locking device is in a temporary stable state still affected by the force of the tensioning device after being limited, the locking device will always indirectly or directly affect the movement of the retaining device. Therefore, when the locking device is disturbed, it will affect the retaining device, and there is a possibility of malfunction caused by leaving the temporary stable state, making it difficult to ensure that it is in a stable and reliable state of being blocked from moving. All products corresponding to this patent on the market are not only provided with an extended bayonet at one end of the guide notch 5e on the retaining device, but also with a butterfly spring that makes the retaining device less susceptible to disturbance and instability (see its Figure 2 The parts shown by the two vertical parallel lines on the left ends of Figures 4a and 4b below objectively confirm the above analysis and experiments. Summary of the invention

[0006] The purpose of the present invention is to address the shortcomings of the above-mentioned prior art and, through structural improvement, propose a multifunctional electric tool that can completely eliminate malfunctions caused by the coordinated action of the locking device and the retaining device, thereby ensuring stable and reliable operation of the retaining device.

[0007] In order to achieve the above object, the multifunctional electric tool of the present invention comprises a tool driving mechanism movable around the axis of the output shaft, wherein the tool driving mechanism comprises at least one hanging device, at least one clamping device and at least one locking device;

[0008] The hanging device can apply a tensioning force to the clamping device, the clamping device has at least one open position for clamping a tool head and at least one closed position for releasing the tool head, the locking device has at least one unlocking position for releasing the clamping device and at least one locking position for blocking the clamping device; the force applied by the tool head to the locking device causes the locking device to move from one of the multiple locking positions to one of the multiple unlocking positions;

[0009] The locking device releases the tensioning force applied by the suspension device to the clamping device by locking the suspension device in at least one locking position.

[0010] After adopting the present invention, the need for coordinated action between the locking device and the clamping device in the prior art to achieve the purpose of the invention is avoided, that is, the displacement of the clamping device will not pull the locking device; and the locking device releases the tensioning force applied to the clamping device by the lifting device in the locked position, so that it no longer relies on the bistable mechanism, but is in a completely stable equilibrium state. Therefore, while having the advantage that the tool head can be installed with one hand by simply pressing down the locking device, the instability after disturbance is completely eliminated, and the clamping device is more stable and reliable whether it is opened to clamp, closed to release, or position changed.

[0011] Furthermore, the locking device comprises at least one trigger component, and when the trigger component is subjected to a force applied by the tool head, the locking device moves from the locking position to the unlocking position.

[0012] Furthermore, the locking device is composed of a locking ring whose outer circle is slidably matched with the inner hole of the output shaft and a locking piece located in the inner hole of the locking ring, and the trigger component is at least one unlocking claw that radially extends from the locking ring and can exceed the lower end of the hollow output shaft.

[0013] Furthermore, the suspension device is composed of a pull rod inserted into the output shaft and a suspension spring sleeved on the pull rod; the pull rod is provided with a recess into which the locking member can be inserted, and the locking member is constrained in a radial through hole of a fixing ring fixed at the lower part of the output shaft.

[0014] Furthermore, when the locking device is in the locking position, the pulling rod of the hanging device is locked by the locking member to release the tensioning force applied by the hanging device to the clamping device.

[0015] Furthermore, the radial through hole on the upper portion of the fixing ring extends into the inner hole of the locking ring, and the inner hole of the locking ring has a small diameter section for pressing the locking member toward the depression of the pull rod and an enlarged diameter section for allowing the locking member to escape from the depression of the pull rod.

[0016] Furthermore, the clamping device is mainly composed of a pair of chucks with a slide groove at the upper part, a hinge hole at the middle part, and an outer hook foot at the lower part; the chuck is hinged to the lower part of the output shaft via a hinge pin passing through the hinge hole.

[0017] Furthermore, the forked lower end of the pull rod is provided with a sliding pin which forms a moving pair with the chuck slide groove.

[0018] Furthermore, the lower end of the tensioning spring is limited to the middle step inside the output shaft, and the upper end is pressed by the tensioning fastener screwed on the pull rod; the tensioning spring of the pull rod is equipped with a downward compression spring located between the tensioning fastener and the locking ring; the stiffness of the downward compression spring is smaller than that of the tensioning spring.

[0019] Furthermore, the hinge pin also fixes the fixing ring and the tool head positioning disk to the lower end of the output shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings.

[0021] Figure 1 The figure is a schematic diagram of the overall structure of an embodiment of the present invention.

[0022] Figure 2 for Figure 1 A schematic diagram of the three-dimensional exploded structure of the tool driving mechanism part of the embodiment.

[0023] Figure 3 for Figure 1 A schematic structural diagram of the embodiment in which the locking device is released and the clamping device is opened and clamped.

[0024] Figure 4 for Figure 3 AA section view.

[0025] Figure 5 for Figure 1 A schematic structural diagram of the locking device of the embodiment and the clamping device in the closed and released state.

[0026] Figure 6 for Figure 5 AA section view. DETAILED DESCRIPTION

[0027] Embodiment 1

[0028] The basic structure of the multifunctional electric tool of this embodiment is as follows: Figure 1As shown, the main body B contains a driving motor, the front end is a tool driving mechanism A, and the rear end is a battery pack C.

[0029] The tool drive mechanism A (equivalent to the tool receiving device in the prior art) can swing around the axis of the hollow output shaft 6 (equivalent to the drive shaft in the prior art) driven by the drive motor through the transmission mechanism. The tool drive mechanism A includes a hanging device (equivalent to the tensioning device in the prior art), a clamping device (equivalent to the holding device in the prior art) and a locking device (equivalent to the locking device in the prior art).

[0030] Among them, the lifting device is mainly composed of a pull rod 9 installed in the output shaft 6 and a lifting spring 4 sleeved on the pull rod 9; the clamping device is mainly composed of a pair of chucks 12 with a slide groove 12-1 on the upper part, a hinged hole in the middle part, and an external hook foot 12-2 on the lower part; the locking device is mainly composed of a locking ring 7 whose outer circle is slidably matched with the inner hole of the output shaft 6 and a locking ball 10 located in the inner hole of the locking ring 7.

[0031] During installation, the lower end of the tensioning spring 4 is limited to the middle step 6-1 in the output shaft 6, and the upper end is screwed on the tensioning nut 1 on the pull rod 9 through the spring washer 2 and the gasket 3, and the forked lower end of the pull rod 9 is equipped with a sliding pin 11 that forms a moving pair with the slide groove of the clamp 12, so that the tensioning device can apply a tensioning force to the clamping device.

[0032] The tie rod 9 is provided with a recess 9-1 into which the locking ball 10 can be inserted. The locking ball 10 is constrained in the radial through hole of the fixing ring 8 fixed at the lower part of the output shaft 6, so it can only move radially. The radial through hole at the upper part of the fixing ring 8 extends into the inner hole of the locking ring 7. The inner hole of the locking ring 7 has a small diameter section that presses the locking ball 10 toward the recess of the tie rod 9 and an enlarged diameter section that allows the locking ball 10 to escape from the recess of the tie rod 9; the locking ring 7 has a pair of unlocking claws 7-1 that extend radially beyond the lower end of the hollow output shaft 6.

[0033] The clamping device 12 is hinged to the lower part of the output shaft 6 via a hinge pin 13 passing through the hinge hole, and has an open position for clamping a saw blade 14 as a tool head (see Figure 3 ) and a closed position that releases the saw blade 14 (see Figure 5 ); The locking device has an unlocked position that releases the clamping device, that is, allows its movement (see Figure 3 ) and a locking position that blocks the clamping device, i.e., prevents it from moving (see Figure 5 ). At the same time, the hinge pin 13 also fixes the fixing ring 8 and the tool head positioning plate 6-2 to the lower end of the output shaft 6.

[0034] When the unlocking claw of the locking ring 7 in the locking device is subjected to the upward force exerted by the saw blade 14, the locking device can be released from Figure 5The locking ball 10 shown in the figure is pressed and stuck in the depression of the pull rod 9 to block the two clamps 12 of the clamping device and make it unable to move. Figure 3 The locking ball 10 is released out of the pull rod 9, and the two clamps 12 of the clamping device are released to the unlocked position so that the clamping device can move. Figure 5 In the locking position shown, the locking ball locks the pull rod 9 of the suspension device, so that the force of the suspension spring 4 does not act on the two clamps 12, thereby releasing the tensioning force applied by the suspension device to the clamping device.

[0035] In order to ensure reliable locking in place when the locking device is switched from the unlocking position to the locking position, the tension spring 4 of the pull rod 9 is also equipped with a downward pressure spring 5 located between the tension nut 1 and the locking ring 7. The rigidity of the downward pressure spring 5 is less than that of the tension spring 4.

[0036] When in Figure 3 , 4 In the unlocked position shown, under the upward tightening force of the tightening spring 4, the sliding pin 11 at the lower end of the pull rod 9 applies a torque around the hinge pin 13 to the chuck 12 through the slide groove 12-1, so that the outer hooks 12-2 of the two chucks 12 are respectively tilted up from both sides to open and clamp the saw blade 14 directed by the tool head positioning disk 6-2. At the same time, the locking ball 10 is forced to be squeezed outward from the depression 9-1 of the pull rod because the pull rod 9 is in the lifting position, and the traction locking ring 7 overcomes the force of the downward pressure spring 5 and rises to the position where the expanded diameter section allows the locking ball 10 to escape from the depression of the pull rod 9.

[0037] During operation, when it is necessary to replace the saw blade 14, the wrench D at the upper end of the tool driving mechanism A is turned to overcome the upward hanging force of the tension spring 4 and press the pull rod 9 downward. The sliding pin 11 at the lower end applies a torque around the hinge pin 13 to the chuck 12 through the slide groove 12-1, so that the outer hooks 12-2 of the two chucks 12 are closed, and the saw blade 14 is released so that it can be removed and replaced as needed. At the same time, the locking ball 10 corresponds to the depression 9-1 of the pull rod due to the pressure drop of the pull rod 9. The locking ring 7 is lowered to the small diameter section under the action of the downward pressure spring 5, and squeezes the locking ball 10 inward, so that it is stuck in the depression of the pull rod 9, and the pull rod 9 is locked. At this time, because the locking device actually isolates the tensioning force of the tension spring 4 on the chuck 12, the clamping device is in a stable closed equilibrium state, and there is no need to worry about malfunction due to disturbance. Only when the unlocking claw 7-1 of the locking ring 7 is subjected to the upward force of the saw blade 14, the chuck 12 will release the clamping device due to the locking ball 10 coming out of the depression of the pull rod 9, and will be restored to the position by the force of the tension spring 4 transmitted by the pull rod 9. Figure 3 , 4 Shown in open clamped state.

[0038] In addition to the above embodiments, the present invention may also have other implementations. For example, the locking ball may be replaced by a locking pin; the pressing spring may be replaced by a butterfly spring; in particular, there are many types of locking devices disclosed in patent documents (such as 201580009468, 201310193660, etc.), and any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A multifunctional electric tool, comprising a tool drive mechanism movable around an output shaft axis, wherein the tool drive mechanism comprises at least one hanging device, at least one clamping device and at least one locking device; The hanging device can apply a tensioning force to the clamping device, the clamping device has at least one open position for clamping a tool head and at least one closed position for releasing the tool head, the locking device has at least one unlocking position for releasing the clamping device and at least one locking position for blocking the clamping device; the force applied by the tool head to the locking device causes the locking device to move from one of the multiple locking positions to one of the multiple unlocking positions; Features: The locking device releases the tensioning force applied by the suspension device to the clamping device by locking the suspension device in at least one locking position.

2. The multifunctional electric tool according to claim 1, characterized in that: The locking device comprises at least one trigger component, and when the trigger component is subjected to a force applied by the tool head, the locking device moves from a locking position to an unlocking position.

3. The multifunctional electric tool according to claim 2, characterized in that: The locking device is composed of a locking ring whose outer circle is slidably matched with the inner hole of the output shaft and a locking member located in the inner hole of the locking ring. The trigger component is at least one unlocking claw that radially extends from the locking ring and can exceed the lower end of the hollow output shaft.

4. The multifunctional electric tool according to claim 3, characterized in that: The suspension device is composed of a pull rod inserted into the output shaft and a suspension spring sleeved on the pull rod; the pull rod is provided with a recess into which the locking member can be inserted, and the locking member is constrained in a radial through hole of a fixing ring fixed at the lower part of the output shaft.

5. The multifunctional electric tool according to claim 4, characterized in that: When the locking device is in the locking position, the locking member locks the pull rod of the hanging device to release the tensioning force applied by the hanging device to the clamping device.

6. The multifunctional electric tool according to claim 5, characterized in that: The radial through hole on the upper part of the fixing ring extends into the inner hole of the locking ring. The inner hole of the locking ring has a small diameter section for pressing the locking member toward the depression of the pull rod and an enlarged diameter section for allowing the locking member to escape from the depression of the pull rod.

7. The multifunctional electric tool according to claim 6, characterized in that: The clamping device is mainly composed of a pair of clamps with slide grooves on the upper part, hinge holes in the middle part and external hook feet on the lower part; the clamps are hinged on the lower part of the output shaft through hinge pins passing through the hinge holes.

8. The multifunctional electric tool according to claim 7, characterized in that: The forked lower end of the pull rod is provided with a sliding pin which forms a moving pair with the chuck sliding groove.

9. The multifunctional electric tool according to claim 8, characterized in that: The lower end of the tension spring is limited to the middle step in the output shaft, and the upper end is held by the tension fastener screwed on the pull rod; the tension spring of the pull rod is equipped with a downward pressure spring located between the tension fastener and the locking ring; the stiffness of the downward pressure spring is smaller than that of the tension spring.

10. The multifunctional electric tool according to claim 9, characterized in that: The hinge pin also secures the retaining ring and the tool head locating disk to the lower end of the output shaft.

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