A function switching mechanism and a power drill

Abstract

The utility model relates to a kind of function switching mechanism and electric drill, function switching mechanism includes: movable limiting part and rotating part, part of movable limiting part is arranged in the limiting hole of front shell, the inner side wall of rotating part has the recess capable of accommodating another part of movable limiting part, rotating part is set on the front shell and rotates around the central axis of front shell;When rotating part rotates to a position, the recess of rotating part and the slot of the limiting hole of front shell are opposite;The inner side wall of rotating part and the surface of movable limiting part contact, to be able to provide stress to movable limiting part, promote the part of movable limiting part to move towards the direction of inner gear ring, the utility model changes the rotation limiting of inner gear ring from original axial indirect limiting to direct radial limiting, effectively limit inner gear ring rotation, reduce the stress damage to electric drill shell.

Description

Technical Field

[0001] This utility model relates to the field of electric drills, and in particular to a function switching mechanism and an electric drill. Background Technology

[0002] Electric drills include multiple function modes, such as screw mode, drill mode, and impact mode, which can be switched between different function modes through a function switching mechanism.

[0003] Chinese patent CN222141910U discloses a gear shifting device for a high-torque electric drill gearbox, which includes a front housing, a power source assembly disposed at the bottom of the front housing, a function switching assembly rotatably sleeved in the middle of the front housing, a torque adjustment assembly rotatably sleeved at the upper end of the front housing, and an output assembly rotatably connected inside the front housing. The lower end of the output assembly is mounted on the power source assembly. The power source assembly includes a planetary gear set and an internal gear ring. The planetary gear set is fixedly connected to the lower end of the output assembly, and the internal gear ring is meshed with the planetary gear set.

[0004] In the aforementioned prior art gear shifting device (CN222141910U), when in drilling mode, the rotation limit of the internal gear ring is achieved by the simultaneous action of the shift shim and the ball pin. When the resistance of the output component reaches a certain value, the limiting mechanism fails and cannot effectively limit the internal gear ring, thus causing the internal gear ring to rotate and preventing the kinetic energy of the motor from being transmitted to the output shaft of the output component. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model proposes a function switching mechanism and an electric drill.

[0006] The technical solution to achieve the purpose of this utility model is as follows: In a first aspect, this utility model provides a function switching mechanism, which includes: a mechanism suitable for an electric drill, the electric drill including an internal gear ring and a front housing, the internal gear ring being disposed within the front housing, the outer side wall of the internal gear ring having a gear ring groove, and the front housing having a limiting hole communicating with the outer side wall of the internal gear ring; the function switching mechanism includes: The movable limiting part is partially disposed within the limiting hole of the front shell; The rotating part has a groove on its inner sidewall that can accommodate another part of the movable limiting part. The rotating part is sleeved on the front shell and rotates about the central axis of the front shell. When the rotating part is rotated to a position, the groove of the rotating part is directly opposite the slot of the limiting hole of the front shell. The inner sidewall of the rotating part is in contact with the surface of the movable limiting part so as to provide stress to the movable limiting part to cause a part of the movable limiting part to move toward the internal gear ring.

[0007] In some embodiments, the rotating portion includes: The rotating cauldron is fitted onto the front shell and its rotation is restricted around the central axis of the front shell; A flexible connection component, comprising several elastic bodies; The movable contact portion has a groove on its inner sidewall that can accommodate the movable limiting portion; the movable contact portion is connected to the rotating cauldron portion via the elastic connecting assembly, so that it can rotate around the central axis of the front shell via the rotating cauldron portion; an elastic body is arranged on the movement path of the movable contact portion to provide elastic buffering for the movable contact portion during rotation.

[0008] In some embodiments, the rotating cauldron includes: A sleeve-shaped operating part; Multiple vertically shaped legs are connected to the operating part and arranged circumferentially along the side wall of the operating part, with an assembly opening formed between two adjacent legs.

[0009] In some embodiments, the sidewall of the operating part has a drill stop mark, an impact stop mark, and a screw stop mark located between the drill stop mark and the impact stop mark.

[0010] In some embodiments, the resilient connection assembly further includes an arc-shaped guide shaft, on which all the elastomers and the movable contact portions are sleeved, and the elastomers are located on both sides of the movable contact portions.

[0011] In some embodiments, the movable limiting portion includes a steel ball.

[0012] Secondly, this utility model provides an electric drill, including the function switching mechanism described in any one of the first aspects.

[0013] In some embodiments, when the electric drill is in drilling mode, a portion of the movable limiting part is located in the limiting hole of the front housing and another portion is located in the gear groove of the internal gear ring, at which time the internal gear ring remains stationary.

[0014] In some embodiments, when the electric drill is in screw working mode, a portion of the movable limiting part is located in the limiting hole of the front housing and another portion is located in the groove of the rotating part, at which time the internal gear ring can rotate.

[0015] The function switching mechanism of this utility model changes the rotation limit of the internal gear ring from the original axial indirect limit to a direct radial limit. That is, by rotating the part, a part of the movable limit part is radially pushed into the gear ring groove of the internal gear ring, and the rotating part provides stress to the movable limit part to keep its position in the gear ring groove of the internal gear ring (when the electric drill is in drilling mode), effectively limiting the rotation of the internal gear ring. In existing electric drills, the rotation limit of the internal gear ring is achieved through the simultaneous action of the skip shim and the ball pin. This limiting structure generates an axial force on the internal gear ring. When the resistance of the output component reaches a certain value, the front and rear housings of the electric drill become loose, the limiting mechanism fails, and the internal gear ring cannot be effectively limited. Consequently, the internal gear ring rotates, preventing the motor's kinetic energy from being transmitted to the output shaft of the output component. However, the function switching mechanism provided by this utility model and the electric drill in which it is applied radially limit the internal gear ring without applying an axial force, effectively overcoming the aforementioned defects of existing electric drills. It can not only keep the internal gear ring from rotating when the electric drill is in drilling mode, but also maintain the stability of the connection structure between the front and rear housings of the electric drill. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the internal structure of an electric drill provided in one embodiment of the present invention; Figure 2 This is a cross-sectional view of an electric drill provided in one embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a portion of the front shell provided in one embodiment of the present invention; Figure 4 This is a schematic diagram of the external structure of the function switching mechanism provided in one embodiment of the present invention, which is assembled in part of the front shell; Figure 5 This is a schematic diagram of the internal structure of the function switching mechanism provided in one embodiment of the present invention, assembled in part of the front shell; Figure 6 This is a schematic diagram of the function switching mechanism provided in one embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the rotating cauldron provided in one embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of the movable contact portion provided in one embodiment of the present invention; Figure 9 This is a cross-sectional view of the functional switching mechanism, gear ring, and front housing of the present invention in one embodiment of the present invention when the electric drill is in screw mode; Figure 10 This is a cross-sectional view of the functional switching mechanism, gear ring, and front housing of the present invention in one embodiment of the present invention when the electric drill is in screw mode; Figure 11This is a vertical cross-sectional view of the functional switching mechanism, gear ring, and front housing provided in one embodiment of the present invention when the electric drill is in the pre-pressed state of screw mode. Figure 12 This is a cross-sectional view of the functional switching mechanism, gear ring, and front housing provided in one embodiment of the present invention when the electric drill is in the pre-pressurized state of screw mode. Figure 13 This is a vertical cross-sectional view of the functional switching mechanism, gear ring, and front housing provided in one embodiment of the present invention when the electric drill is in screw mode and in a clamping state. Figure 14 This is a cross-sectional view of the functional switching mechanism, gear ring, and front housing provided in one embodiment of the present invention when the electric drill is in screw mode and in a tightening state. Detailed Implementation

[0017] The present embodiment will now be described in conjunction with the accompanying drawings. In each drawing, the same or equivalent parts are indicated by the same reference numerals. In the description of the embodiment, the description of the same or equivalent parts is omitted or simplified as appropriate.

[0018] This utility model provides an electric drill that solves the problem that in existing electric drills, when in drilling mode, the rotation limit of the internal gear ring is achieved by the simultaneous action of the skip shim and the ball head pin. When the resistance of the output component reaches a certain value, the limiting mechanism fails and cannot effectively limit the internal gear ring, causing the internal gear ring to rotate and preventing the motor's kinetic energy from being transmitted to the output shaft of the output component.

[0019] like Figure 1-2 As shown, in one embodiment, the electric drill includes a housing 10, which includes a front housing 101 and a rear housing 102. The front housing 101 and the rear housing 102 can be threaded together. A transmission mechanism 20, a motor 30, an output shaft 40, and a function switching mechanism 50 are installed inside the housing 10. The motor 30 is connected to the transmission mechanism 20. The transmission mechanism 20 includes a planetary carrier, an internal gear ring 202, a planetary gear set consisting of several planetary gears, and a sun gear. The planetary gear set is located outside the sun gear and inside the internal gear ring 202. The planetary gear set meshes with both the sun gear and the internal gear ring 202. The planetary gear set is connected to the planetary carrier. When the motor 30 is started, the motor 30 provides power and transmits it to the transmission mechanism 20.

[0020] like Figure 3-5As shown, in some embodiments, the front cover 101 includes a main body base 1011, an upper cover 1012 and a lower cover 1013, wherein the main body base 1011 has a central body 10111 extending along the height direction in the central region inside, the central body 10111 is hollow inside, and the output shaft 40 of the electric drill is mounted on the central body 10111 with its head end axially protruding from the inner side of the central body 10111. The lower cover 1013 is annular and located on the outer side of the central body 10111 near its lower part. A gap exists between the lower cover 1013 and the central body 10111 to form an annular groove. The central body 10111 has a radially protruding projection 10111a at one location, extending to the inner wall of the upper cover 1012. The top of the projection 10111a has a sliding contact plane and three recessed slots 10111b formed by the plane (for smooth contact with the rotating cauldron 5021 to switch between screw, drill, and impact modes). The three slots 10111b are arranged circumferentially and spaced apart from each other. The central body 10111 has two partitions at approximately opposite positions to the projection 10111a, extending to the inner wall of the upper cover 1012. The annular groove is divided into two arc-shaped grooves 101a by the protrusion 10111a and the partition. The two arc-shaped grooves 101a are used to install the lower part of the rotating part 502 (e.g., guide shaft 50222, movable contact part 5023, and elastic body 50221). The upper cover 1012 is annular and located near the upper outer side of the central body 10111. The operating part 50211 of the rotating cauldron 5021 (described in detail below) is arranged between the upper cover 1012 and the lower cover 1013.

[0021] like Figure 1 , Figure 2 and Figure 9 As shown, the internal gear ring 202 is installed inside the front housing 101. The outer side wall of the internal gear ring 202 has a radially open gear groove 2021. The front housing 101 has a limiting hole that communicates with the outer side wall of the internal gear ring 202. The purpose is that when the electric drill is in drilling mode, the limiting hole of the front housing 101 can be aligned with the groove of the gear groove 2021 of the internal gear ring 202. A part of the movable limiting part 501 can be pushed into the gear groove 2021 of the internal gear ring 202 under the action of the rotating part 502, thus completing the fixation of the internal gear ring 202.

[0022] like Figure 4 As shown, in some embodiments, the function switching mechanism 50 includes: a movable limiting part 501 and a rotating part 502.

[0023] like Figure 14As shown, a portion of the movable limiting part 501 is placed inside the limiting hole of the front housing 101. The internal space of the limiting hole of the front housing 101 is insufficient to accommodate the entire movable limiting part 501. The purpose is to expose a portion of the movable limiting part 501 outside the limiting hole of the front housing 101, so that the rotating part 502 can contact the movable limiting part 501. Then, when the electric drill is in drilling mode, the rotating part 502 can squeeze the movable limiting part 501, causing a portion of the movable limiting part 501 to be pushed into the gear groove 2021 of the internal gear ring 202, thus fixing the internal gear ring 202. In some embodiments, the movable limiting part 501 includes a steel ball.

[0024] The inner wall of the rotating part 502 has a groove that can accommodate another part of the movable limiting part 501. The rotating part 502 is sleeved on the front shell 101 and rotates around the central axis of the front shell 101 (i.e. the central axis of the output shaft 40). like Figure 6 As shown, in some embodiments, the rotating portion 502 includes: a rotating cauldron portion 5021, an elastic connecting assembly 5022, and a movable contact portion 5023.

[0025] The rotating cauldron 5021 is fitted onto the front housing 101 and its rotation is restricted around the central axis of the front housing 101. This is because the entire electric drill switches between working modes (such as drilling mode and screw mode) by rotating the rotating cauldron 5021. Specifically, this involves switching between screw mode, drill mode, and impact mode. The switching between modes is achieved by rotating the rotating cauldron 5021 at a certain angle, but the rotation range is not large. In order to facilitate the operation of the electric drill by the operator, the rotation of the rotating cauldron 5021 around the central axis of the front housing 101 is restricted, so that its rotation range is limited.

[0026] like Figure 7As shown, in some embodiments, the rotating cauldron 5021 includes: a sleeve-shaped operating part 50211 and a plurality of vertically shaped legs 50212. The operating part 50211 has a roughly circular cross-section, and its inner sidewall has a radially extending columnar body 50213. The rotation path of the columnar body 50213 involves the top surface of the protrusion 10111a of the front housing 101. Thus, the bottom surface of the columnar body 50213 can contact the gear slot 10111b of the front housing 101. Therefore, when the operator rotates the operating part 50211 to switch the working mode of the electric drill, a shifting sensation and friction sound will be generated. The cooperation between the columnar body 50213 and the gear slot 10111b of the front housing 101 can improve the operator's operating feel, making it easier for them to use the electric drill. It also has the function of maintaining the position of the rotating pedestal part 5021. The operating part 50211 is located between the upper cover 1012 and the lower cover 1013 of the aforementioned front housing 101. The upper ends of the legs 50212 are connected to the inner sidewall of the operating part 50211 and are circumferentially spaced apart from the columnar body 50213. The lower ends of the legs 50212 extend vertically into the arcuate groove 101a of the front shell 101 located below the operating part 50211, and an assembly opening is formed between two adjacent legs 50212. In some embodiments, the sidewall of the operating part 50211 has markings 50214, such as a drill stop marking, an impact stop marking, and a screw stop marking located between the drill stop marking and the impact stop marking. By rotating the drill stop marking, the impact stop marking, and the live screw stop marking to the designated position, the function corresponding to the marking 50214 is switched.

[0027] like Figure 6 and Figure 8 As shown, the inner wall of the movable contact portion 5023 has a groove that can accommodate the movable limiting portion 501; the movable contact portion 5023 is connected to the rotating tripod portion 5021 through the elastic connecting assembly 5022, so that it can rotate around the central axis of the front shell 101 through the rotating tripod portion 5021; an elastic body 50221 is arranged on the movement path of the movable contact portion 5023 to provide elastic buffering for the movable contact portion 5023 during rotation. In some embodiments, the active contact portion 5023 is block-shaped, including a main block 50231, an upper connector 50232, and a lower connector 50233. The main block 50231 is located between the upper connector 50232 and the lower connector 50233, and the upper connector 50232 is located above the lower connector 50233. Both the upper connector 50232 and the lower connector 50233 have through holes for the guide shaft 50222 to pass through. The upper connector 50232 and the lower connector 50233 are arranged approximately symmetrically around the main block 50231.

[0028] like Figure 6As shown, the elastic connection assembly 5022 includes a plurality of elastic bodies 50221; in some embodiments, the elastic body 50221 includes a spring; in some embodiments, the number of elastic connection assemblies 5022 is two sets, and each set of elastic connection assemblies 5022 further includes: an arc-shaped guide shaft 50222, the number of guide shafts 50222 is two, the two ends of each guide shaft 50222 pass through a leg 50212 corresponding to the rotating tripod portion 5021 and are fixedly connected to the outside of the center body 10111 of the front shell 101, and the two guide shafts 50222 are spaced vertically apart. In the open arrangement, the elastic body 50221 is sleeved on the corresponding guide shaft 50222. The elastic body 50221 is located on both sides of the movable contact portion 5023 and between the two corresponding legs 50212 of the rotating tripod portion 5021. There is one movable contact portion 5023 corresponding to each set of elastic connecting components 5022. The two guide shafts 50222 in each set of elastic connecting components 5022 pass through the through holes of the upper connecting body 50232 and the lower connecting body 50233 in a movable contact portion 5023, thereby completing the construction of the rotating part 502. The rotation of the legs 50212 of the rotating tripod portion 5021 will cause the elastic body 50221 to compress, thereby providing thrust to the movable contact portion 5023. The movable contact portion 5023 transmits this thrust to the movable limiting portion 501, so that when the electric drill is in drilling mode, a part of the movable limiting portion 501 enters the gear groove 2021 of the internal gear ring 202.

[0029] When the rotating part 502 is rotated to a position, the groove of the rotating part 502 is directly opposite to the slot of the limiting hole of the front shell 101; the inner sidewall of the rotating part 502 contacts the surface of the movable limiting part 501 so as to provide stress to the movable limiting part 501 to cause a part of the movable limiting part 501 to move in the direction of the internal gear ring 202.

[0030] like Figure 9-10 As shown, when the electric drill is in screw mode (e.g., the electric drill is in screw mode), the sun gear 204 rotates as power input, the planet carrier 201 is fixed, the planet gear set 203 drives the internal gear ring 202 to rotate, the power is disconnected, the output shaft 40 stops rotating, part of the movable limiting part 501 is located in the limiting hole of the front housing 101 and the other part is located in the groove of the rotating part 502 (movable contact part 5023), at this time, the internal gear ring 202 can rotate.

[0031] like Figure 11-14 As shown, when the electric drill is in drilling mode (e.g., in drill mode or impact mode), the sun gear 204 rotates as power input, the internal gear ring 202 is fixed, the sun gear 204 drives the planetary gear set 203 to rotate, the planetary gear set 203 drives the planet carrier 201 to rotate, and the planet carrier 201 transmits power to the output shaft 40, causing the output shaft 40 to rotate. During this process, the movable contact part 5023 has the following conditions: (1) One side of the movable contact part 5023 moves to the other side due to the pressure of the elastic body 50221 caused by the rotation of the rotating sleeve, but is blocked by the movable limiting part 501 and does not move to the neutral position. (2) One side of the movable contact part 5023 moves to the other side due to the pressure of the elastic body 50221 caused by the rotation of the rotating sleeve. The inner gear ring 202 rotates. A part of the movable limiting part 501 is located in the limiting hole of the front shell 101 and the other part is located in the gear groove 2021 of the inner gear ring 202. The movable contact part 5023 moves to the neutral position due to the pressure of the elastic body 50221 and abuts against the movable limiting part 501, so that the inner gear ring 202 cannot rotate. The electric drill will not skip gears and can successfully drill.

[0032] The function switching mechanism 50 of this utility model changes the rotation limit of the internal gear ring 202 from the original indirect axial limit to a direct radial limit. That is, by rotating the rotating part 502, a part of the movable limiting part 501 is radially pushed into the gear ring groove 2021 of the internal gear ring 202. The rotating part 502 provides stress to the movable limiting part 501 to keep a part of its position in the gear ring groove 2021 of the internal gear ring 202 (when the electric drill is in drilling mode), effectively limiting the rotation of the internal gear ring 202. In existing electric drills, the rotation limit of the internal gear ring 202 is achieved through the simultaneous action of the skip shim and the ball head pin. This limiting structure generates an axial force on the internal gear ring. When the resistance experienced by the output component reaches a certain value, the front and rear housings of the electric drill become loose, the limiting mechanism fails, and the internal gear ring cannot be effectively limited. Consequently, the internal gear ring rotates, preventing the motor's kinetic energy from being transmitted to the output shaft of the output component. However, the function switching mechanism provided by this utility model and the electric drill in which it is applied radially limit the internal gear ring without applying an axial force, effectively overcoming the aforementioned defects of existing electric drills. It not only keeps the internal gear ring from rotating when the electric drill is in drilling mode, but also avoids damage to the connection structure between the front and rear housings of the electric drill.

[0033] The foregoing is merely intended to illustrate the principles of this utility model. Furthermore, since many modifications and variations will readily occur to those skilled in the art, it is not intended to limit this utility model to the exact structures and operations shown and described. Although preferred embodiments have been described, details may be changed without departing from the essential concept of this utility model. Therefore, the technical solutions involved in this utility model include not only the technical solutions disclosed above, but also technical solutions composed of equivalent substitutions of technical features in the technical solutions involved in this utility model. Matters not covered in this utility model are common knowledge to those skilled in the art.

Claims

1. A function switching mechanism suitable for an electric drill, the electric drill comprising an internal gear ring and a front housing, the internal gear ring being disposed within the front housing, characterized in that, The inner gear ring has a gear groove on its outer side wall, and the front housing has a limiting hole communicating with the outer side wall of the inner gear ring. The function switching mechanism includes: The movable limiting part is partially disposed within the limiting hole of the front shell; The rotating part has a groove on its inner sidewall that can accommodate another part of the movable limiting part. The rotating part is sleeved on the front shell and rotates about the central axis of the front shell. When the rotating part is rotated to a position, the groove of the rotating part is directly opposite the slot of the limiting hole of the front shell. The inner sidewall of the rotating part is in contact with the surface of the movable limiting part so as to provide stress to the movable limiting part to cause a part of the movable limiting part to move toward the internal gear ring.

2. The function switching mechanism according to claim 1, characterized in that, The rotating portion includes: The rotating cauldron is fitted onto the front shell and its rotation is restricted around the central axis of the front shell; A flexible connection component, comprising several elastic bodies; The movable contact portion has a groove on its inner sidewall that can accommodate the movable limiting portion; the movable contact portion is connected to the rotating cauldron portion via the elastic connecting assembly, so that it can rotate around the central axis of the front shell via the rotating cauldron portion; an elastic body is arranged on the movement path of the movable contact portion to provide elastic buffering for the movable contact portion during rotation.

3. The function switching mechanism according to claim 2, characterized in that, The rotating cauldron includes: A sleeve-shaped operating part; Multiple vertically shaped legs are connected to the operating part and arranged circumferentially along the side wall of the operating part, with an assembly opening formed between two adjacent legs.

4. The function switching mechanism according to claim 3, characterized in that, The side wall of the operating part has a drill stop mark, an impact stop mark, and a screw stop mark located between the drill stop mark and the impact stop mark.

5. The function switching mechanism according to claim 2, characterized in that, The elastic connection assembly further includes an arc-shaped guide shaft, on which all the elastic bodies and the movable contact portions are sleeved, and the elastic bodies are located on both sides of the movable contact portions.

6. The function switching mechanism according to claim 1, characterized in that, The movable limiting part includes a steel ball.

7. An electric drill, characterized in that, Includes the function switching mechanism described in any one of claims 1-6.

8. The electric drill according to claim 7, characterized in that: When the electric drill is in drilling mode, part of the movable limiting part is located in the limiting hole of the front housing and another part is located in the tooth groove of the internal tooth ring. At this time, the internal tooth ring remains stationary.

9. The electric drill according to claim 7, characterized in that: When the electric drill is in screw working mode, part of the movable limiting part is located in the limiting hole of the front shell and the other part is located in the groove of the rotating part. At this time, the internal gear ring can rotate.

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