Handheld ground drill earth boring machine with safety protection structure

Abstract

The utility model discloses a handheld earth boring earth boring machine with a safety protection structure, which comprises an earth boring earth boring machine body and an earth boring bit, the earth boring earth boring machine body comprises a support, an engine, a reduction gearbox, an accelerator switch and a flameout switch, the engine, the reduction gearbox, the accelerator switch and the flameout switch are arranged on the support, and a crankshaft of the engine is connected with a centrifugal clutch used for transmitting power to the reduction gearbox. The engine is provided with an igniter, the igniter is provided with a control chip, the control chip is connected with a rotating speed sensor and a reset switch, the support is provided with a safety braking device, the safety braking device comprises a shell, a triggering piece, a braking switch and a triggering rod, and the triggering piece is arranged in the shell and can rotate relative to the shell. The trigger rod is connected with the trigger piece and can drive the trigger piece to rotate, a reset spring is arranged on the shell, and when the trigger piece is driven by the trigger rod to rotate to the position in contact with the brake switch, the brake switch is triggered to be in a switched-on state, so that the speed of an engine is reduced to an idling state, and good safety protection is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a ground drill, especially to a handheld ground drill pit digger with safety protection structure. BACKGROUND

[0002] The ground drill is widely applied to the planting and pit digging of nursery and landscaping engineering on slope land, sandy land and hard land, the fence pile burying and hole digging, the fertilizer hole digging of fruit trees and forest trees and the cultivation of landscaping engineering to liberate people's heavy physical labor. The ground drill is generally controlled by the flameout switch arranged on the handle of the supporting frame.

[0003] For example, the patent CN207470121U discloses a ground drill, which comprises an engine and a supporting frame.

[0004] When the ground drill works, it may meet hard rock or other foreign matters, which may cause the drill bit to stop suddenly, and the torsion of the machine may act on the ground drill frame suddenly, drive the ground drill frame to rotate at high speed, and easily hurt the operator, cause accidents and have safety hidden danger, so the safety is low. UTILITY MODEL CONTENTS

[0005] Based on the problem that the ground drill may meet hard rock or other foreign matters when working, which may cause the drill bit to stop suddenly, the torsion of the machine may act on the ground drill frame suddenly, drive the ground drill frame to rotate at high speed, easily hurt the operator, cause accidents and have safety hidden danger, the utility model provides a handheld ground drill pit digger with safety protection structure.

[0006] The utility model discloses a technical scheme that solves the above technical problem is as follows: handheld ground drill pit digger with safety protection structure, including ground drill pit digger body and ground drill head, ground drill pit digger body includes support, the engine of being installed on the support, reduction gearbox, throttle switch and flameout switch, the crankshaft of engine is connected for the centrifugal clutch of transmission power to reduction gearbox, and the output end of ground drill head is connected with reduction gearbox, and the centrifugal clutch cuts off the transmission of power when the engine speed is not higher than the set speed, be equipped with the igniter for ignition on the engine, and the control chip that controls ignition is equipped with on the igniter, and the control chip is connected for the speed sensor and reset switch of detecting engine speed, be equipped with safety brake device on the support, and safety brake device includes the casing, trigger, brake switch and trigger lever, and the trigger is arranged in the casing and can rotate relative to the casing, and the trigger lever is coupled with the trigger and can drive the trigger to rotate, and the projection part of trigger lever on the plane perpendicular to the axial direction of ground drill head is at least partially located on the outside of the projection part of support on the plane perpendicular to the axial direction of ground drill head, be equipped with reset spring on the casing and drive the trigger to rotate and reset, brake switch is correspondingly arranged on the side of trigger, and brake switch and flameout switch are connected with control chip,

[0007] When the trigger is rotated to the position of contacting with brake switch by the trigger lever, brake switch is triggered and is in the on state, and the control chip controls the igniter to ignite only when the engine speed is not higher than the set speed, so that the engine is reduced to idle speed,

[0008] When reset switch is triggered and is in the on state, the control chip removes the ignition limitation of the igniter.

[0009] The utility model further optimizes the technical scheme as follows: the trigger is rotatably connected in the casing through the pivot, the pivot extends out of the casing through the bottom of the casing, one end of the trigger lever is connected with one end of the pivot extending out of the casing, and the axial direction of the pivot is parallel to the axial direction of the ground drill head.

[0010] The utility model further optimizes the technical scheme as follows: the outer edge of the trigger is provided with an arc abutting surface, the distance from the arc abutting surface to the axial line of the pivot gradually increases from one end to the other end, the trigger rotates to control the arc abutting surface to contact or separate from the brake switch, and when the arc abutting surface is pressed on the brake switch, the brake switch is triggered and is in the on state.

[0011] The utility model further optimizes the technical scheme as follows: the trigger includes a rotating connecting piece fixedly connected with the pivot, and a pressing part with a thickness greater than the rotating connecting piece is fixed on one side of the rotating connecting piece, and the outer edge of the pressing part forms the arc abutting surface.

[0012] The utility model further preferably discloses the technical scheme: the trigger lever includes first rod, second rod and connecting spring, the second rod is fixed on the pivot, and the first rod is connected with the second rod through the connecting spring.

[0013] The utility model further preferably discloses the technical scheme: the bottom opening is fixed with the connecting seat at the bottom opening of the shell, and the upper end of the connecting seat is provided with the first bearing groove that is communicated with the bottom opening in the upward slot, the lower end of the connecting seat is provided with the second bearing groove that is communicated with the bottom opening in the downward slot, the first bearing groove is connected with the second bearing groove through the communicating hole, the first bearing is arranged in the first bearing groove, the second bearing is arranged in the second bearing groove, the pivot passes through the center of the first bearing and the second bearing, the pivot is clamped with the first clamping spring that is limited above the first bearing and the second clamping spring that is limited below the second bearing, the pivot includes the shaft body, the connecting column is arranged on the upper end surface of the shaft body, the connecting column and the shaft body form the step, the upper end surface of the connecting column is provided with the threaded connection part, the trigger piece is sleeved on the connecting column, the fastening nut is threadedly connected on the threaded connection part, and the fastening nut locks the trigger piece, one end of the trigger lever is provided with the insertion hole, the lower end of the shaft body is provided with the insertion part, the insertion part is inserted into the insertion hole and is fixedly connected with the trigger lever through the screw.

[0014] The utility model further preferably discloses the technical scheme: the support includes the base, two U-shaped bent pipes fixed on the left and right sides of the base and the top frame fixed on the top of the two U-shaped bent pipes, the engine is installed on the base and is accommodated in the support, the top frame includes the rod body that is located on the left and right sides of the engine and extends longitudinally, and the longitudinally-extending rod bodies on the two sides are used as handle portions for holding.

[0015] The utility model further preferably discloses the technical scheme: the shell is provided with the limited rotation part on one side corresponding to the trigger piece, when the trigger piece rotates and the arc-shaped abutting surface contacts the brake switch, the trigger piece abuts on the limited rotation part and is limited to rotate by the limited rotation part.

[0016] The utility model further preferably discloses the technical scheme: the handle is installed on the handle portion on one side, and the ignition switch, the throttle switch and the reset switch are arranged on the control handle.

[0017] The utility model further preferably discloses the technical scheme: the centrifugal clutch includes the shoe connected on the engine crankshaft, the driven disc matched with the shoe, and the input end of the speed reducer connected with the driven disc, the shoe is engaged with the driven disc through the centrifugal force generated when rotating to drive the driven disc to rotate, when the rotating speed of the engine is not higher than the set rotating speed, the shoe is separated from the driven disc to cut off the power transmission.

[0018] Compared with the prior art, the advantages of the utility model are that when the ground drill bit is suddenly stopped due to hard rock stratum or other foreign matters, the torsion of the engine acts on the support to drive the support to rotate, the trigger lever touches the human body in the process of the support rotating and rotates relative to the support under the block of the human body, the trigger lever drives the trigger piece in the shell to rotate, the trigger piece rotates to the position of contacting the brake switch to trigger the brake switch, the brake switch is in the on state, the control chip receives the signal sent by the brake switch and controls the igniter to ignite only when the engine rotating speed is not higher than the set rotating speed, so that the engine is slowed down, the centrifugal clutch cuts off the power transmission when the engine is slowed down to not higher than the set rotating speed, the engine is in the idle speed state, the operator is prevented from being hurt by the high-speed rotation of the support, the safety protection is increased, and the engine does not need to be turned off and stopped, when the ground drill is needed to dig again, the user only needs to trigger the reset switch to make the control chip release the ignition limitation of the igniter, at this time, the operator can improve the engine rotating speed through the accelerator switch, the centrifugal clutch retransmits the power of the engine to the ground drill bit, the ground drill bit rotates to work again, and it is more suitable for the operator to use. BRIEF DESCRIPTION OF DRAWINGS

[0019] The utility model will be described further in detail below by combining with the drawings and preferred embodiments, but the person skilled in the art will appreciate that these drawings are only drawn for the purpose of explaining the preferred embodiments and therefore should not be regarded as the limitation to the scope of the utility model. In addition, unless specifically indicated, the drawings only schematically show the composition or structure of the described object conceptually and can contain exaggerated display, and the drawings are not necessarily drawn to scale.

[0020] Figure 1 It is the structural schematic diagram of ground drill pit digger;

[0021] Figure 2 It is the top view of the utility model;

[0022] Figure 3 It is the structural schematic diagram of ground drill pit digger bottom;

[0023] Figure 4 It is the structural schematic diagram of safety brake device being installed on the support;

[0024] Figure 5 It is the split schematic diagram of safety brake device and support;

[0025] Figure 6 It is the top view when the trigger piece contacts the brake switch after the trigger lever is blocked;

[0026] Figure 7 It is Figure 6 the partial close-up view of A of

[0027] Figure 8 is a top view of the trigger lever in the initial position;

[0028] Figure 9 is a partial enlarged view of B of Figure 8

[0029] Figure 10 is a schematic view of the overall structure of the safety brake device;

[0030] Figure 11 is a schematic view of the safety brake device in cross section;

[0031] Figure 12 is an exploded view of the trigger lever and the rotating shaft;

[0032] Figure 13 is an exploded view of the reset switch and the housing;

[0033] Figure 14 , an exploded view of the trigger lever.

[0034] In the figure: 1, earth drill body; 2, earth drill head; 3, trigger lever; 4, support; 5, housing; 6, engine; 7, starter; 8, igniter; 9, flywheel; 10, shoe; 11, tension spring; 12, handle part; 13, control handle; 14, throttle switch; 15, stop switch; 16, top frame; 17, wire hole; 18, U-shaped bend pipe; 19, base; 20, L-shaped fold plate; 21, fixed plate; 22, reset switch; 23, trigger piece; 24, arc-shaped abutting surface; 25, brake switch; 26, rotation limiting part; 27, connecting seat; 28, second lever; 29, first lever; 30, decorative cover; 31, insertion hole; 32, insertion part; 33, first snap spring; 34, second bearing; 35, second bearing groove; 36, first bearing groove; 37, first bearing; 38, shaft body; 39, reset spring; 40, connecting column; 41, sleeve hole; 42, threaded connecting part; 43, nut; 44, lower half housing; 45, upper half housing; 46, lower support seat; 47, upper support seat; 48, embedding groove; 49, positioning hole; 50, positioning column; 51, limiting plate; 52, connecting spring; 53, touch pressure part; 54, bottom opening; 55, rotating connecting piece; 56, communication hole; 57, second snap spring. DETAILED DESCRIPTION

[0035] Preferred embodiments of the present application will be described in detail below with reference to the attached drawings. Those skilled in the art will appreciate that the description is merely illustrative, exemplary, and should not be construed as limiting the scope of the present application.

[0036] ​It should be noted that like reference numerals refer to like elements throughout the several views of the drawings and that, while several views can utilize the same reference number, the definition of these reference numbers can change from one drawing to another, as more fully described below.

[0037] Figures 1-14 As shown, the handheld earth drill with safety protection structure comprises an earth drill body 1 and an earth drill bit 2, the earth drill bit 2 is connected to the earth drill body 1, and the earth drill body 1 can drive the earth drill bit 2 to rotate and work.

[0038] Figures 1-3 As shown, the earth drill body 1 comprises a support 4, an engine 6 mounted on the support 4, a reduction gearbox, a throttle switch 14 and an engine stop switch 15, the crankshaft of the engine 6 is connected to a centrifugal clutch for transmitting power to the reduction gearbox, the earth drill bit 2 is connected to the output end of the reduction gearbox, and the centrifugal clutch cuts off the power transmission when the rotating speed of the engine 6 is not higher than a set rotating speed. The structure of the engine 6 transmitting power to the earth drill bit 2 through the reduction gearbox can refer to the patent CN218912807U.

[0039] The centrifugal clutch comprises shoe blocks 10 connected to the crankshaft of the engine 6, driven discs matched with the shoe blocks 10, the shoe blocks 10 are installed on the side surface of the flywheel 9 fixed to the crankshaft of the engine 6 through shoe block pins, adjacent shoe blocks 10 are connected by tension springs 11, the driven discs are rotatably mounted on the shell of the engine 6 and coaxially arranged with the crankshaft, the driven discs are covered outside the shoe blocks 10, the driven discs are connected to the input end of the reduction gearbox through transmission shafts, and the earth drill bit 2 is connected to the output end of the reduction gearbox.

[0040] When the crankshaft drives the flywheel 9 to rotate and the shoe blocks 10 engage with the driven discs through centrifugal force, the shoe blocks 10 drive the driven discs to rotate, input power to the reduction gearbox, and transmit the power to the earth drill bit 2 through the reduction gearbox to drive the earth drill bit 2 to rotate and work.

[0041] When the rotating speed of the engine 6 is not higher than the set rotating speed, the centrifugal force generated during rotation is not enough to overcome the elastic force of the tension springs 11 to throw the shoe blocks 10 away from the driven discs, at this time, the shoe blocks 10 are separated from the driven discs to cut off the power transmission, the shoe blocks 10 do not drive the driven discs to rotate, and thus the driven discs do not transmit power to the reduction gearbox and the earth drill bit 2, at this time, the engine 6 is in an idle state. The set rotating speed is, for example, 2800±300 revolutions.

[0042] The reduction gearbox can be a planetary gear reduction gearbox or other reduction gearbox.

[0043] The structure of the above centrifugal clutch for transmitting power is a conventional structure, and can refer to the clutch device in the patent CN2536490Y, the clutch in the patent CN203655952U, and the clutch in the patent CN102726172B.

[0044] The engine 6 is provided with an igniter 8 for ignition, and the igniter 8 is provided with a control chip for controlling ignition of the igniter 8, the control chip is connected with a rotation speed sensor for detecting rotation speed of the engine 6 and a reset switch 22,

[0045] The rotation speed sensor is a sensing device available in the market, for example, a magnetic speed sensor with a brand of Hangzhou Zeus and a signal of ZSM12-CS-01, a sensing part of the rotation speed sensor can be arranged on the igniter 8, and a magnet cooperating with the sensing part can be arranged on the flywheel 9, the magnet passes through a sensing range of the sensing part during rotation of the flywheel 9, so as to detect the rotation speed of the engine 6.

[0046] Figure 2 、 Figure 4 As shown in the figure, the support 4 is provided with a safety braking device, the mounting braking device includes a housing 5, a trigger 23, a braking switch 25 and a trigger rod 3, the trigger 23 is arranged in the housing 5 and can rotate relative to the housing 5, the trigger rod 3 is coupled with the trigger 23 and can drive the trigger 23 to rotate, a projection part of the trigger rod 3 on a plane perpendicular to an axial direction of the earth drill bit 2 is at least partially located outside a projection part of the support 4 on the plane perpendicular to the axial direction of the earth drill bit 2, the housing 5 is provided with a reset spring 39 for driving the trigger 23 to rotate and reset, and the braking switch 25 and the above-mentioned switch 15 are connected with the control chip.

[0047] In operation, the switch 15 is adjusted to an on state, the igniter 8 starts to ignite, the user can start the engine 6 through the starter 7 on the engine 6, the engine 6 outputs power to drive the earth drill bit 2 to rotate, and the user controls the rotating earth drill bit 2 to drill the ground.

[0048] Figures 6-9When the rotating earth drill 2 encounters hard rock or other foreign objects and is suddenly stopped, the engine 6 rotates and the torque acts on the support 4 to drive the support 4 to rotate, the trigger rod 3 rotates with the support 4 until the trigger rod 3 touches the body of the operator, and the trigger rod 3 rotates relative to the support 4 under the resistance of the body, the trigger rod 3 drives the trigger 23 in the shell 5 to rotate, the trigger 23 rotates to the position where the trigger 23 contacts the brake switch 25 to trigger the brake switch 25, so that the brake switch 25 is in the on state, at this time the control chip receives the signal sent by the brake switch 25, and controls the igniter 8 to ignite only when the engine 6 rotates at a speed not higher than the set speed, so as to reduce the speed of the engine 6, when the engine 6 is reduced to a speed not higher than the set speed, the centrifugal clutch cuts off the power transmission, and the engine 6 is in an idle state, avoiding the high-speed rotation of the support 4 to harm the operator and increasing the safety protection, and the engine 6 does not need to be turned off, when the earth drill is needed to be used again to dig a pit, the user only needs to trigger the reset switch 22 to make the control chip release the ignition limitation of the igniter 8, at this time the operator can improve the speed of the engine 6 through the accelerator switch 14, so that the centrifugal clutch retransmits the power of the engine 6 to the earth drill 2, and the earth drill 2 rotates to work again, which is more suitable for the operator to use.

[0049] Figure 10 As shown, the trigger 23 is rotatably connected in the shell 5 through a rotating shaft, the rotating shaft extends out of the shell 5 through the bottom of the shell 5, one end of the trigger rod 3 is connected with one end of the rotating shaft extending out of the shell 5, and the axial direction of the rotating shaft is parallel to the axial direction of the earth drill 2.

[0050] Figures 11-13As shown, specifically, the bottom of the shell 5 is provided with a bottom opening 54, and a connecting seat 27 is fixed at the outside of the shell 5 at the bottom opening 54. The upper end of the connecting seat 27 is provided with a first bearing groove 36 which is communicated with the bottom opening 54 in a slot upward direction, and the lower end of the connecting seat 27 is provided with a second bearing groove 35 which is communicated with the bottom opening 54 in a slot downward direction. The first bearing groove 36 and the second bearing groove 35 are connected through a communication hole 56. The first bearing groove 36 is provided with a first bearing 37, and the second bearing groove 35 is provided with a second bearing 34. The rotating shaft passes through the centers of the first bearing 37 and the second bearing 34. The rotating shaft is provided with a first circlip 33 which is limited above the first bearing 37 and a second circlip 57 which is limited below the second bearing 34. The rotating shaft is rotatably arranged on the shell 5. The rotating shaft comprises a shaft body 38. The upper end face of the shaft body 38 is provided with a connecting column 40. The connecting column 40 and the shaft body 38 form a step. The upper end face of the connecting column 40 is provided with a threaded connection part 42. The trigger piece 23 is provided with a sleeve hole 41 which is sleeved with the connecting column 40. The trigger piece 23 is sleeved on the connecting column 40. The threaded connection part 42 is threadedly connected with a fastening nut 43. The fastening nut 43 locks the trigger piece 23, so that the trigger piece 23 is fixed with the rotating shaft. One end of the trigger lever 3 is provided with a insertion hole 31. The lower end of the shaft body 38 is provided with an insertion part 32. The insertion part 32 is inserted into the insertion hole 31 and is fixedly connected with the trigger lever 3 through a screw.

[0051] The hole wall of the sleeve hole 41 can be provided with a straight edge. The connecting column 40 is provided with a corresponding straight surface. When the trigger piece 23 is sleeved on the connecting column 40, the straight edge and the straight surface form clamping limiting, so as to limit the rotation of the trigger piece 23 relative to the rotating shaft. The connection between the trigger piece 23 and the rotating shaft is more stable.

[0052] The outer edge of the trigger piece 23 is provided with an arc-shaped abutting surface 24. The distance from the arc-shaped abutting surface 24 to the axis line of the rotating shaft gradually increases from one end to the other end. The arc-shaped abutting surface 24 is rotatably controlled to contact or separate from the brake switch 25. When the arc-shaped abutting surface 24 is pressed on the brake switch 25, the brake switch 25 is triggered to be in an on state. The different distances from the arc-shaped abutting surface 24 to the axis line of the rotating shaft enable the arc-shaped abutting surface 24 to contact and separate from the brake switch 25 when the trigger piece 23 rotates.

[0053] The trigger piece 23 comprises a rotating connecting piece 55 which is fixedly connected with the rotating shaft. The rotating connecting piece 55 is provided with the sleeve hole 41. One side of the rotating connecting piece 55 is fixedly provided with a pressing part 53 which has a thickness greater than that of the rotating connecting piece 55. The outer edge of the pressing part 53 forms the arc-shaped abutting surface 24. The thickness of the pressing part 53 is greater than that of the rotating connecting piece 55, so that the arc-shaped abutting surface 24 has sufficient width to contact the brake switch 25.

[0054] The reset spring 39 is a torsion spring, one end of which is connected to the shell 5, and the other end of which is connected to the trigger 23, and the reset spring 39 provides an elastic force to the trigger 23.

[0055] Figure 14 As shown, the trigger lever 3 comprises a first lever 29, a second lever 28 and a connecting spring 52, the second lever 28 is fixed to the rotating shaft, the first lever 29 is connected to the second lever 28 through the connecting spring 52, the first lever 29 is located at the outer side and serves as a contact part for the trigger lever 3 to touch the human body, and the connecting spring 52 can be elastically deformed when the first lever 29 touches the human body to play a certain buffering role.

[0056] A decorative cover 30 is arranged at the connection between the first lever 29 and the second lever 28, the decorative cover 30 wraps the connecting spring 52, so that the trigger lever 3 is more beautiful, the decorative cover 30 is made of elastic rubber or silicone material, and the elasticity of the decorative cover 30 does not affect the elastic deformation of the connecting spring 52.

[0057] In addition, a limiting rotation part 26 is arranged at one side of the trigger 23 in the shell 5, when the trigger 23 rotates and the arc-shaped abutting surface 24 contacts the brake switch 25, the trigger 23 abuts against the limiting rotation part 26 and is limited in rotation by the limiting rotation part 26, the maximum rotation angle of the trigger 23 is limited by the limiting rotation part 26, so that the problem that the brake switch 25 is pressed and damaged when the trigger 23 continues to rotate after the arc-shaped abutting surface 24 contacts the brake switch 25 is avoided.

[0058] Preferably, the limiting rotation part 26 is a convex edge fixed to the inner bottom of the shell 5, and the convex edge is arranged at one side of the trigger 23.

[0059] The shell 5 comprises an upper half shell 45 and a lower half shell 44, and the upper half shell 45 and the lower half shell 44 are fixed by screws after being closed.

[0060] Figure 13 As shown, the lower bottom of the lower half shell 44 is fixed with a lower support base 46, the two sides of the lower support base 46 are provided with upward extending limiting plates 51, the limiting plates 51 form an embedding groove 48 therebetween, the brake switch 25 is embedded in the embedding groove 48, the bottom of the embedding groove 48 is provided with a positioning hole 49, the brake switch 25 is provided with a positioning column 50 inserted into the positioning hole 49, and the upper bottom of the upper half shell 45 is fixed with an upper support base 47, when the upper half shell 45 and the lower half shell 44 are closed and connected, the upper support base 47 presses down on the top of the brake switch 25, so that the brake switch 25 is fixed between the upper support base 47 and the lower support base 46.

[0061] Preferably, the brake switch 25 is a travel switch.

[0062] Figure 4 、 Figure 5As shown, the support frame 4 comprises a base 19, two U-shaped bent pipes 18 fixed on the left and right sides of the base 19, and a top frame 16 fixed on the top of the two U-shaped bent pipes 18, the engine 6 and the reduction box are mounted on the base 19 and accommodated in the support frame 4, the top frame 16 comprises rod bodies extending longitudinally on the left and right sides of the engine 6, the two side longitudinal rod bodies are used as the handle portions 12 for holding, and the housing 5 is fixed on the inner side of the handle portion 12 on one side.

[0063] Specifically, the support frame is fixed with an L-shaped folded plate 20 and a transversely extending fixing plate 21, and the housing 5 is fixed on the L-shaped folded plate 20 and the fixing plate 21.

[0064] The handle portion 12 on one side is provided with a control handle 13, and the fire switch 15, the throttle switch 14 and the reset switch 22 are arranged on the control handle 13.

[0065] The top frame 16 can be a closed loop or a non-closed loop annular structure.

[0066] The housing 5 is provided with a wire hole 17 for connecting the power supply line.

[0067] The hand-held ground drilling and digging machine with the safety protection structure is introduced above, the principle and the implementation mode of the present application are described by applying specific examples in the present application, and the above examples are only used for helping to understand the present application and the core idea. It should be pointed out that for ordinary skilled in the art, without departing from the principle of the present application, the present application can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the present application.

Claims

1. A handheld earth drill with a safety protection structure, comprising an earth drill body and an earth drill head. The earth drill body comprises a bracket, an engine mounted on the bracket, a reduction gearbox, a throttle switch, and a flameout switch. The engine crankshaft is connected to a centrifugal clutch for transmitting power to the reduction gearbox. The earth drill head is connected to the output end of the reduction gearbox. The centrifugal clutch cuts off power transmission when the engine speed is not higher than a set speed. The invention is characterized in that: The engine is provided with an igniter for ignition, the igniter is provided with a control chip for controlling the ignition, the control chip is connected to a speed sensor for detecting the engine speed and a reset switch, the bracket is provided with a safety brake device, the safety brake device includes a shell, a trigger, a brake switch and a trigger rod, the trigger is arranged in the shell and can rotate relative to the shell, the trigger rod is connected to the trigger and can drive the trigger to rotate, the projection of the trigger rod on a plane perpendicular to the axis of the drill bit is at least partially located outside the projection of the bracket on a plane perpendicular to the axis of the drill bit, the shell is provided with a reset spring for driving the trigger to reset after rotation, the brake switch is correspondingly arranged on one side of the trigger, and the brake switch and the flameout switch are both connected to the control chip. When the trigger member is driven by the trigger rod to rotate to the position of contact with the brake switch, the brake switch is triggered and is in the on state. The control chip controls the ignition to ignite only when the engine speed is not higher than the set speed, so that the engine slows down to the idle state. When the reset switch is triggered and is in the on state, the control chip releases the ignition restriction on the igniter.

2. The handheld earth drilling and digging machine with a safety protection structure according to claim 1, characterized in that: The trigger member is rotatably connected to the shell through a rotating shaft, and the rotating shaft passes downward through the bottom of the shell and extends out of the shell. One end of the trigger rod is connected to the end of the rotating shaft extending out of the shell, and the axial direction of the rotating shaft is parallel to the axial direction of the earth drill bit.

3. The handheld earth drilling and digging machine with a safety protection structure according to claim 2, characterized in that: An arc-shaped abutment surface is provided on the outer edge of the trigger member, and the distance between the arc-shaped abutment surface and the axis center line of the rotating shaft gradually increases from one end to the other end. The trigger member rotates to control the arc-shaped abutment surface to contact or separate from the brake switch. When the arc-shaped abutment surface contacts and presses on the brake switch, the brake switch is triggered and is in the on state.

4. The handheld earth drilling and digging machine with a safety protection structure according to claim 3, characterized in that: The trigger member includes a rotating connecting piece fixedly connected to the rotating shaft, a contact and pressure portion having a thickness greater than that of the rotating connecting piece is fixed on one side of the rotating connecting piece, and an outer edge of the contact and pressure portion forms the arc-shaped abutting surface.

5. The handheld earth drilling and digging machine with a safety protection structure according to claim 2, characterized in that: The trigger rod includes a first rod, a second rod and a connecting spring. The second rod is fixed on the rotating shaft. The first rod and the second rod are connected by the connecting spring.

6. The handheld earth drilling and digging machine with a safety protection structure according to claim 2, characterized in that: The bottom of the shell is provided with a bottom opening, and a connecting seat located outside the shell is fixed at the bottom opening, the upper end of the connecting seat is provided with a first bearing groove that is connected with the bottom opening upwardly with a notch, and the lower end of the connecting seat is provided with a second bearing groove that is notched downwardly, and the first bearing groove and the second bearing groove are connected by a communicating hole, and the first bearing groove is provided with a first bearing, and the second bearing groove is provided with a second bearing, and the rotating shaft passes through the center of the first bearing and the second bearing, and is clamped on the rotating shaft with a first retaining spring limited above the first bearing and a second retaining spring limited below the second bearing. The rotating shaft includes a shaft body, a connecting column is provided on the upper end surface of the shaft body, a step is formed between the connecting column and the shaft body, a threaded connection portion is provided on the upper end surface of the connecting column, the trigger piece is sleeved on the connecting column, and a fastening nut is threadedly connected to the threaded connection portion, and the fastening nut locks the trigger piece, and one end of the trigger rod is provided with a socket, and the lower end of the shaft body is provided with an insertion portion, the insertion portion is inserted in the socket, and is fixedly connected to the trigger rod by a screw.

7. The handheld earth drilling and digging machine with a safety protection structure according to claim 1, characterized in that: The bracket includes a base, two U-shaped curved tubes fixed on the left and right sides of the base, and a top frame fixed on the top of the two U-shaped curved tubes. The engine is mounted on the base and accommodated inside the bracket. The top frame includes rods located on the left and right sides of the engine and extending longitudinally. The rods extending longitudinally on both sides serve as handles for holding, and the shell is fixed on the inner side of the handle on one side.

8. The handheld earth drilling and digging machine with a safety protection structure according to claim 3, characterized in that: A rotation limiting portion is provided on one side of the trigger member in the housing. When the trigger member rotates and the arc-shaped abutting surface contacts the brake switch, the trigger member abuts against the rotation limiting portion and its rotation is limited by the rotation limiting portion.

9. The handheld earth drilling and digging machine with a safety protection structure according to claim 7, characterized in that: A control handle is mounted on the handle portion on one side, and the flameout switch, throttle switch and reset switch are all arranged on the control handle.

10. The handheld earth drilling and digging machine with a safety protection structure according to claim 5, characterized in that: The centrifugal clutch includes a shoe connected to the engine crankshaft and a driven plate that cooperates with the shoe. The driven plate is connected to the input end of the reduction gearbox. The shoe engages with the driven plate through the centrifugal force generated during rotation to drive the driven plate to rotate. When the engine speed is not higher than the set speed, the shoe separates from the driven plate to cut off the power transmission.

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