Rock core drill

Abstract

The present invention addresses the problem of effectively cooling a controller. A core drill is provided with: a motor having a stator and a rotor that rotates about a rotation axis extending in the front-rear direction with respect to the stator; a speed reduction mechanism which is disposed in front of the stator and decelerates the rotation of the rotor; an output shaft, at least a part of which is disposed further forward than the speed reduction mechanism, and which rotates by the rotational force of the rotor transmitted by the speed reduction mechanism in a state in which the core drill is attached; a storage battery assembly part on which the storage battery pack is assembled; a motor accommodating part for accommodating the motor; at least a part of the handle part is arranged on an extension line of the rotating shaft at a position closer to the rear than the motor accommodating part; and a controller that controls the motor. At least a portion of the controller is disposed between the motor and the handle portion in the front-rear direction.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a core drill (English: core drill, Japanese: コアドリル). Background Art

[0002] In the technical field related to core drills, core drills disclosed in Patent Documents 1, 2, and 3 are known.

[0003] Patent Document 1: U.S. Patent No. 010710172

[0004] Patent Document 2: U.S. Patent Application Publication No. 2022 / 0154534

[0005] Patent Document 3: U.S. Patent Application Publication No. 2022 / 0258256 Summary of the invention

[0006] When the core drill is provided with a controller, it is desirable to effectively cool the controller.

[0007] An object of the technology disclosed in this specification is to effectively cool a controller.

[0008] The present specification discloses a core drill. The core drill may include: a motor having a stator and a rotor, the rotor rotating relative to the stator with a rotation axis extending in the front-rear direction as the center; a speed reduction mechanism arranged at a position further forward than the stator and reducing the rotation of the rotor; an output shaft, at least a portion of which is arranged at a position further forward than the speed reduction mechanism and rotates by the rotational force of the rotor transmitted by the speed reduction mechanism when the core drill bit is installed; a battery assembly portion for assembling a battery pack; a motor housing portion for housing the motor; a handle portion, at least a portion of which is arranged on an extension line of the rotation axis at a position further rearward than the motor housing portion; and a controller for controlling the motor. At least a portion of the controller may be arranged between the motor and the handle portion in the front-rear direction.

[0009] Effects of the Invention

[0010] According to the technology disclosed in this specification, the controller can be cooled efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The core drill according to the first embodiment is shown in a perspective view when viewed from the upper right front.

[0012] Figure 2 This is a diagram showing the core drill according to the first embodiment as viewed from above.

[0013] Figure 3 This is a diagram showing the core drill according to the first embodiment as viewed from the front.

[0014] Figure 4 This is a diagram showing the core drill according to the first embodiment as viewed from the right side.

[0015] Figure 5 It is a cross-sectional view showing the core drill according to the first embodiment.

[0016] Figure 6 This is a diagram showing the motor according to the first embodiment as viewed from the right side.

[0017] Figure 7 This is a diagram showing the speed reduction mechanism according to the first embodiment as viewed from above.

[0018] Figure 8 This is a diagram showing a state where a core drill bit is mounted on a spindle of the core drill according to the first embodiment.

[0019] Fig. 9 This is a diagram showing the core drill according to the second embodiment as viewed from the right side.

[0020] Fig.10 This is a diagram showing the core drill according to the third embodiment as viewed from the right side.

[0021] Fig.11 This is a diagram showing the core drill according to the fourth embodiment as viewed from the right side.

[0022] Fig.12 This is a diagram showing the core drill according to the fifth embodiment as viewed from above.

[0023] Fig.13 This is a diagram showing the core drill according to the sixth embodiment as viewed from above.

[0024] Fig.14 This is a diagram showing the core drill according to the seventh embodiment as viewed from the right side.

[0025] Fig.15 This is a diagram showing the core drill according to the eighth embodiment as viewed from the right side.

[0026] Fig.16 It is a cross-sectional view showing a core drill according to a ninth embodiment.

[0027] Fig.17 It is a cross-sectional view showing a core drill according to a tenth embodiment.

[0028] Fig.18 It is a cross-sectional view showing a core drill according to an eleventh embodiment.

[0029] Fig.19It is a cross-sectional view showing a core drill according to a twelfth embodiment.

[0030] Description of Reference Numerals

[0031] 1A…Core drill, 1B…Core drill, 1C…Core drill, 1D…Core drill, 1E…Core drill, 1F…Core drill, 1G…Core drill, 1H…Core drill, 1J…Core drill, 1K…Core drill, 1L…Core drill, 1M…Core drill, 2…Main body, 2L…Left main body, 2R…Right main body, 2S…Screw, 3…Motor box, 4…Gear box, 4S…Screw, 5…Gear housing, 5S…Screw, 6…Side handle, 7...battery assembly, 8...motor, 9...fan, 10...controller, 11...speed reduction mechanism, 12...spindle, 13...trigger shifter, 14...water supply pipe, 15...battery pack, 16...motor bracket, 17...speed switching lever, 18...trigger switch, 19...core drill bit, 21...motor storage part, 22...battery connection part, 23...controller storage part, 24...handle, 24A...upper handle, 24B...lower handle, 24C…rear handle, 25…air inlet, 26…exhaust port, 30…gear, 31…intermediate shaft, 32…gear, 33…gear, 34…gear, 35…gear, 36…gear, 37…conversion ring, 51…rotor bearing, 52…rotor bearing, 53…main shaft bearing, 54…main shaft bearing, 71…first battery assembly, 72…second battery assembly, 81…stator, 82…rotor, 83…rotor shaft, 84…stator core, 85…insulator, 86…coil, 87…rotor core, 88…rotor magnet, 89…bus bar unit, 101…first controller, 102…second controller, 151…first battery pack, 152…second battery pack, 700…battery assembly part, 1500…battery pack, AX…output rotating shaft, D…stator outer diameter, L…stator length, H…opening diameter, MX…motor rotating shaft. DETAILED DESCRIPTION

[0032] In one or more embodiments, the core drill may include: a motor having a stator and a rotor, the rotor rotating relative to the stator around a rotation axis extending in the front-rear direction; a speed reduction mechanism arranged at a position further forward than the stator and reducing the rotation of the rotor; an output shaft, at least a portion of which is arranged at a position further forward than the speed reduction mechanism and rotates by the rotational force of the rotor transmitted by the speed reduction mechanism when the core drill bit is mounted; a battery mounting portion for mounting a battery pack; a motor housing portion for housing the motor; a handle portion, at least a portion of which is arranged on an extension line of the rotation axis at a position further rearward than the motor housing portion; and a controller for controlling the motor. At least a portion of the controller may be arranged between the motor and the handle portion in the front-rear direction.

[0033] According to the above structure, the controller can be effectively cooled. In addition, the handle is arranged on the extension line of the rotating shaft of the motor, and at least a part of the controller is arranged between the motor and the handle, so that the operator can easily operate the core drill. For example, since the weight balance of the core drill is improved, the core drill is easy to operate.

[0034] In one or more embodiments, the core drill may include: a controller housing portion disposed between the motor housing portion and the handle portion. The controller may be housed in the controller housing portion.

[0035] According to the above configuration, since the weight balance of the core drill is improved, the core drill can be easily operated.

[0036] In one or more embodiments, an air inlet may be provided in the controller housing.

[0037] According to the above configuration, the controller can be cooled effectively.

[0038] In one or more embodiments, the controller may include: a first controller and a second controller. The first controller may be accommodated in the handle, and the second controller may be arranged between the motor and the handle.

[0039] According to the above configuration, the controller is divided to suppress the increase in size of the controller. By suppressing the increase in size of the controller, the increase in size of the core drill is suppressed, and the core drill is easily operated.

[0040] In one or more embodiments, the controller may include: a first controller and a second controller. The first controller and the second controller may be respectively arranged between the motor and the handle.

[0041] According to the above configuration, the controller is divided to suppress the increase in size of the controller. By suppressing the increase in size of the controller, the increase in size of the core drill is suppressed, and the core drill is easily operated.

[0042] Hereinafter, the embodiments of the present disclosure will be described with reference to the accompanying drawings, but the present disclosure is not limited to the embodiments. The structural elements of the embodiments described below can be combined appropriately. In addition, some structural elements may not be used.

[0043] In the embodiments, the positional relationship of each part is described using the terms "left", "right", "front", "rear", "upper", and "lower". The above terms represent relative positions or directions based on the center of the core drill. The left-right direction, the front-back direction, and the upper-lower direction are orthogonal to each other.

[0044] [First embodiment]

[0045] A first embodiment will be described.

[0046] <Core Drill>

[0047] Figure 1 The core drill 1A according to the present embodiment is shown in a perspective view when viewed from the upper right front. Figure 2 This is a diagram showing the core drill 1A according to the present embodiment as viewed from above. Figure 3 This is a diagram showing the core drill 1A according to the present embodiment as viewed from the front. Figure 4 This is a diagram showing the core drill 1A according to the present embodiment as viewed from the right side. Figure 5 It is a cross-sectional view showing a core drill 1A according to the present embodiment.

[0048] In the present embodiment, the core drill 1A is a rechargeable diamond core drill.

[0049] The core drill 1A includes a main body housing 2 , a motor box 3 , a gear box 4 , a gear housing 5 , a side handle 6 , a battery mounting portion 7 , a motor 8 , a fan 9 , a controller 10 , a speed reduction mechanism 11 , a main shaft 12 , a trigger shifter 13 , and a water supply pipe 14 .

[0050] The main body shell 2 is made of synthetic resin. The main body shell 2 includes: a left main body shell 2L and a right main body shell 2R. The right main body shell 2R is arranged on the right side of the left main body shell 2L. The left main body shell 2L and the right main body shell 2R constitute a pair of half-split shells. The left main body shell 2L and the right main body shell 2R are fixed by a plurality of screws 2S.

[0051] The main body case 2 includes a motor housing portion 21 , a battery connection portion 22 , a controller housing portion 23 , and a handle portion 24 .

[0052] The motor housing portion 21 houses the motor case 3 . The motor case 3 houses the motor 8 . The motor housing portion 21 houses the motor 8 via the motor case 3 .

[0053] The battery connection portion 22 holds the battery mounting portion 7 . The battery connection portion 22 is disposed on the lower side of the motor housing portion 21 .

[0054] The controller housing portion 23 houses the controller 10 . The controller housing portion 23 is disposed on the rear side of the motor housing portion 21 .

[0055] The handle 24 is held by the operator. The handle 24 is arranged at a position further back than the motor housing 21. The handle 24 is arranged on the rear side of the controller housing 23. The controller housing 23 is arranged between the motor housing 21 and the handle 24 in the front-rear direction.

[0056] The handle portion 24 includes an upper handle portion 24A extending rearward from the upper portion of the controller housing portion 23, a lower handle portion 24B extending rearward from the lower portion of the controller housing portion 23, and a rear handle portion 24C connecting the rear portion of the upper handle portion 24A with the rear portion of the lower handle portion 24B. The trigger shifter 13 is disposed on the upper portion of the rear handle portion 24C.

[0057] The gear box 4 accommodates at least a portion of the speed reduction mechanism 11. The gear box 4 is connected to the front portion of the motor housing portion 21. The front portion of the motor box 3 is arranged between the front portion of the motor housing portion 21 and the rear portion of the gear box 4. The gear box 4 is connected to the front portion of the motor housing portion 21 via the motor box 3. The front portion of the motor box 3 and the rear portion of the gear box 4 are fixed by a plurality of screws 4S.

[0058] The gear housing 5 accommodates at least a part of the speed reduction mechanism 11. The gear housing 5 accommodates the main shaft 12. The gear housing 5 is connected to the front part of the gear box 4. The front part of the gear box 4 and the rear part of the gear housing 5 are fixed by a plurality of screws 5S.

[0059] The side handle 6 is held by the operator. The side handle 6 is fixed to the left side of the gear housing 5. The side handle 6 protrudes from the left portion of the gear housing 5 to the left.

[0060] The battery mounting portion 7 holds the battery pack 15. The battery mounting portion 7 is disposed below the battery connection portion 22. The battery mounting portion 7 includes a terminal block connected to the battery pack 15. The battery pack 15 is mounted on the battery mounting portion 7. The battery pack 15 is attached to and detached from the battery mounting portion 7.

[0061] In this embodiment, two battery mounting parts 7 are provided. The battery mounting part 7 includes a first battery mounting part 71 and a second battery mounting part 72. The structure and size of the terminal block of the first battery mounting part 71 and the structure and size of the terminal block of the second battery mounting part 72 are identical to each other. The first battery mounting part 71 and the second battery mounting part 72 are connected in series.

[0062] The first battery mounting portion 71 and the second battery mounting portion 72 are arranged adjacent to each other in the front-rear direction. The first battery mounting portion 71 is arranged on the rear side of the second battery mounting portion 72. The battery pack 15 includes a first battery pack 151 mounted on the first battery mounting portion 71 and a second battery pack 152 mounted on the second battery mounting portion 72.

[0063] like Figure 3 As shown by the arrow, the battery pack 15 is mounted on the battery mounting portion 7 by sliding from the left side to the right side of the battery mounting portion 7. The battery pack 15 is mounted on the battery mounting portion 7 in a sliding manner.

[0064] The first battery pack 151 is mounted on the first battery mounting portion 71 by sliding it from the left side to the right side of the first battery mounting portion 71. The first battery mounting portion 71 has terminal terminals. When the first battery pack 151 is mounted on the first battery mounting portion 71, the connection terminals of the first battery pack 151 are connected to the terminal terminals of the first battery mounting portion 71. The first battery pack 151 is removed from the first battery mounting portion 71 by sliding it to the left side from the first battery mounting portion 71. The first battery pack 151 is mounted and removed from the first battery mounting portion 71.

[0065] The second battery pack 152 is mounted on the second battery mounting portion 72 by sliding it from the left side to the right side of the second battery mounting portion 72. The second battery mounting portion 72 has a terminal terminal. When the second battery pack 152 is mounted on the second battery mounting portion 72, the connection terminal of the second battery pack 152 is connected to the terminal terminal of the second battery mounting portion 72. The second battery pack 152 is removed from the second battery mounting portion 72 by sliding it to the left side from the second battery mounting portion 72. The second battery pack 152 is mounted and removed from the second battery mounting portion 72.

[0066] The battery pack 15 functions as a power source for the core drill 1A. The battery pack 15 includes a secondary battery. In the present embodiment, the battery pack 15 includes a rechargeable lithium-ion battery. The battery pack 15 is mounted on the battery mounting portion 7, so that power can be supplied to the core drill 1A. The first battery pack 151 and the second battery pack 152 are connected in series. The motor 8 is driven based on the power supplied from the first battery pack 151 and the second battery pack 152, respectively. The controller 10 operates based on the power supplied from the first battery pack 151 and the second battery pack 152, respectively.

[0067] The motor 8 functions as a power source of the core drill 1A. The motor 8 is an inner rotor type DC brushless motor. The motor 8 is accommodated in the motor case 3. The motor case 3 is accommodated in the motor accommodation portion 21 of the main body case 2. The motor 8 is accommodated in the motor accommodation portion 21 via the motor case 3.

[0068] Figure 6 1 is a diagram of the motor 8 according to the present embodiment as viewed from the right side. The motor 8 includes a stator 81, a rotor 82, and a rotor shaft 83. The stator 81 is fixed to the motor case 3 so as not to rotate. At least a portion of the rotor 82 is disposed inside the stator 81. The rotor shaft 83 is fixed to the rotor 82. The rotor 82 rotates relative to the stator 81 around the motor rotation axis MX extending in the front-rear direction.

[0069] The stator 81 includes a stator core 84 having an annular yoke and a plurality of teeth protruding radially inward from the inner peripheral surface of the yoke, an insulator 85 fixed to the stator core 84, and a plurality of coils 86 respectively wound around the plurality of teeth of the stator core 84 via the insulator 85. The plurality of coils 86 are connected via a bus bar unit 89.

[0070] The rotor 82 rotates around the motor rotation axis MX and includes a rotor core 87 and a rotor magnet 88 fixed to the rotor core 87 .

[0071] The sensor substrate (not shown) is fixed to the insulator 85. The sensor substrate supports a rotation detection element that detects the position of the rotor 82 in the rotation direction. The rotation detection element detects the position of the rotor magnet 88 to detect the position of the rotor 82 in the rotation direction.

[0072] The rotor shaft 83 is fixed to the rotor core 87. The rotor 82 and the rotor shaft 83 rotate together around the motor rotation axis MX.

[0073] The rotor shaft 83 is rotatably supported by the rotor bearing 51 and the rotor bearing 52. The rotor bearing 51 rotatably supports the rear portion of the rotor shaft 83 protruding rearward from the rear end face of the rotor 82. The rotor bearing 52 rotatably supports the front portion of the rotor shaft 83 protruding forward from the front end face of the rotor 82. The rotor bearing 51 is held by the motor case 3. The rotor bearing 52 is held by the motor bracket 16 fixed to the rear portion of the gear case 4.

[0074] The fan 9 generates an airflow for cooling the motor 8 and the controller 10. The fan 9 is arranged in front of the stator 81. The fan 9 is fixed to the front of the rotor shaft 83. The fan 9 is arranged between the stator 81 and the rotor bearing 52. The fan 9 rotates together with the rotor shaft 83.

[0075] Air inlets 25 are provided at the left and right portions of the controller housing 23, respectively. Exhaust ports 26 are provided at the left and right portions of the front portion of the motor box 3, respectively. The air in the external space of the main body case 2 flows into the internal space of the controller housing 23 through the air inlets 25 by the rotation of the fan 9. The controller 10 is cooled by the air flowing into the internal space of the controller housing 23 circulating in the internal space of the controller housing 23. The air circulating in the internal space of the controller housing 23 flows into the internal space of the motor box 3 through the vent provided at the rear portion of the motor box 3 by the rotation of the fan 9. The air flowing into the internal space of the motor box 3 circulates in the internal space of the motor box 3 to cool the motor 8. At least a portion of the air circulating in the internal space of the motor box 3 flows out to the external space of the motor box 3 through the exhaust ports 26 by the rotation of the fan 9.

[0076] The controller 10 outputs a control signal for controlling the motor 8. The controller 10 includes a circuit board on which a plurality of electronic components are mounted. Examples of the electronic components mounted on the circuit board include a processor such as a CPU (Central Processing Unit), a nonvolatile memory such as a ROM (Read Only Memory) or a storage, a volatile memory such as a RAM (Random Access Memory), a field effect transistor (FET), and a resistor. The controller 10 is housed in a controller housing portion 23.

[0077] The controller 10 is arranged at a position behind the motor 8. At least a part of the controller 10 is arranged on an extension line of the motor rotation axis MX. That is, at least a part of the controller 10 and the motor rotation axis MX are arranged at the same position in the vertical direction and the horizontal direction.

[0078] The handle portion 24 is arranged at a position further back than the controller 10. At least a portion of the handle portion 24 is arranged at a position further back than the motor housing portion 21 and on an extension line of the motor rotation axis MX. That is, at least a portion of the handle portion 24 and the motor rotation axis MX are arranged at the same position in the vertical direction and the left-right direction, respectively. In the present embodiment, at least a portion of the rear handle portion 24C and the motor rotation axis MX are arranged at the same position in the vertical direction and the left-right direction, respectively. In the present embodiment, at least a portion of the trigger shifter 13 and the motor rotation axis MX are arranged at the same position in the vertical direction and the left-right direction, respectively.

[0079] In the front-rear direction, at least a portion of the controller 10 is disposed between the motor 8 and the handle portion 24 .

[0080] The speed reduction mechanism 11 transmits the rotational force of the motor 8 to the main shaft 12. The speed reduction mechanism 11 connects the rotor shaft 83 and the main shaft 12. The speed reduction mechanism 11 reduces the rotation of the rotor 82 and transmits it to the main shaft 12. The speed reduction mechanism 11 rotates the main shaft 12 at a rotation speed lower than the rotation speed of the rotor shaft 83. The speed reduction mechanism 11 reduces the rotation of the rotor 82 at a predetermined speed reduction ratio. The speed reduction mechanism 11 is arranged at a position further forward than the stator 81.

[0081] The gear 30 is fixed to the front end portion of the rotor shaft 83. The rotor shaft 83 is connected to the speed reduction mechanism 11 via the gear 30.

[0082] Figure 71 is a diagram of the speed reduction mechanism 11 according to the present embodiment as viewed from above. The speed reduction mechanism 11 includes an intermediate shaft 31, a gear 32 fixed to the rear portion of the intermediate shaft 31, a gear 33 fixed to the front portion of the intermediate shaft 31, and a gear 34 fixed to the intermediate shaft 31 at a position further forward than the gear 33. In addition, the speed reduction mechanism 11 includes a gear 35 fixed to the rear portion of the main shaft 12, and a gear 36 supported by the main shaft 12 at a position further forward than the gear 35. The intermediate shaft 31 is arranged at a position further to the left than the rotor shaft 83 and the main shaft 12. The gear 30 meshes with the gear 32. The gear 33 can mesh with the gear 35. The gear 34 can mesh with the gear 36.

[0083] When the rotor shaft 83 rotates, the intermediate shaft 31 connected to the rotor shaft 83 via the gears 30 and 32 rotates. The rotation of the intermediate shaft 31 causes the main shaft 12 connected to the intermediate shaft 31 via the gears 33, 35 and the gears 34, 36 to rotate.

[0084] The reduction gear mechanism 11 is capable of changing the reduction ratio. The reduction ratio of the reduction gear mechanism 11 is changed by operating the speed switching lever 17 provided at the lower portion of the gear housing 5. The change ring 37 between the gear 35 and the gear 36 is moved in the front-to-rear direction by operating the speed switching lever 17. The reduction ratio of the reduction gear mechanism 11 is changed by moving the change ring 37 in the front-to-rear direction. If the reduction ratio of the reduction gear mechanism 11 is changed to the first reduction ratio, the main shaft 12 rotates at the first speed (low speed). If the reduction ratio of the reduction gear mechanism 11 is changed to the second reduction ratio, the main shaft 12 rotates at the second speed (high speed) higher than the first speed. In the following description, the state in which the reduction gear mechanism 11 is in the first reduction ratio is appropriately referred to as the low-speed mode, and the state in which the reduction gear mechanism 11 is in the second reduction ratio is appropriately referred to as the high-speed mode.

[0085] The main shaft 12 is an output shaft that rotates by the rotational force of the rotor 82 transmitted via the speed reduction mechanism 11 when the core drill bit is mounted. The main shaft 12 is arranged in front of the rotor shaft 83. At least a part of the main shaft 12 is arranged in front of the speed reduction mechanism 11.

[0086] The main shaft 12 is rotatable around the output rotation axis AX extending in the front-rear direction. The output rotation axis AX and the motor rotation axis MX may not be consistent. In the embodiment, the output rotation axis AX and the motor rotation axis MX are parallel. The main shaft 12 is rotatably supported by the main shaft bearing 53 and the main shaft bearing 54, respectively. The main shaft bearing 53 is held by the gear housing 5. The main shaft bearing 54 is held by the gear box 4.

[0087] Figure 8The figure shows a state where the core drill bit 19 is mounted on the spindle 12 of the core drill 1A according to the present embodiment. When the spindle 12 is rotated by the rotational force generated by the motor 8, the core drill bit 19 mounted on the front end of the spindle 12 rotates together with the spindle 12.

[0088] The operator operates the trigger paddle 13 to drive the motor 8. The trigger paddle 13 protrudes forward from the front portion of the upper portion of the rear handle portion 24C. A trigger switch 18 is disposed inside the rear handle portion 24C. The operator operates the trigger paddle 13 in a manner of moving it backward. By operating the trigger paddle 13 in a manner of moving it backward, an operation signal for driving the motor 8 is sent from the trigger switch 18 to the controller 10. The controller 10 supplies a drive current for driving the motor 8 to the motor 8 based on the operation signal from the trigger switch 18. The driving of the motor 8 is stopped by releasing the operation of the trigger paddle 13.

[0089] The water supply pipe 14 supplies water to the core bit 19. The water supply pipe 14 is connected to the gear housing 5. The water supplied from the water supply pipe 14 to the inside of the gear housing 5 passes through the inside of the main shaft 12, and is then supplied to the core bit 19.

[0090] [Each element]

[0091] like Figure 6 As shown, the stator outer diameter D representing the outer diameter of the stator core 84 is greater than 75 mm. The stator outer diameter D is: the size of the stator core 84 in the direction perpendicular to the motor rotating shaft MX. The upper limit of the stator outer diameter D is not particularly limited and can be 120 mm. That is, the stator outer diameter D can be greater than 75 mm and less than 120 mm. In addition, the stator outer diameter D can be greater than 80 mm, can be greater than 85 mm, can be greater than 90 mm, can be greater than 95 mm, can be greater than 100 mm, can be greater than 105 mm, can be greater than 110 mm. In the present embodiment, the stator outer diameter D is 80 mm.

[0092] The stator length L indicating the axial dimension of the stator core 84 is greater than or equal to 30 mm. The stator length L is the dimension of the stator core 84 in the direction parallel to the motor rotating shaft MX. The upper limit of the stator length L is not particularly limited and may be 65 mm. That is, the stator length L may be greater than or equal to 30 mm and less than or equal to 65 mm. In addition, the stator length L may be greater than or equal to 35 mm, may be greater than or equal to 40 mm, may be greater than or equal to 45 mm, may be greater than or equal to 50 mm, or may be greater than or equal to 55 mm. In the present embodiment, the stator length L is 50 mm.

[0093] like Figure 7As shown, the hole diameter H representing the outer diameter of the terminal end (front end) of the core drill bit 19 is greater than 155 mm. The upper limit of the hole diameter H is not particularly limited and can be 200 mm. That is, the hole diameter H can be greater than 155 mm and less than 200 mm. In addition, the hole diameter H can be greater than 160 mm, can be greater than 165 mm, can be greater than 170 mm, can be greater than 175 mm, can be greater than 180 mm, can be greater than 185 mm, can be greater than 190 mm. In this embodiment, the hole diameter H is 160 mm.

[0094] The reduction ratio of the reduction mechanism 11 can be greater than 1 / 16 and less than 1 / 5. For example, the first reduction ratio of the reduction mechanism 11 in the low speed mode can be greater than 1 / 16 and less than 1 / 12. The second reduction ratio of the reduction mechanism 11 in the high speed mode can be greater than 1 / 9 and less than 1 / 5. In this embodiment, the first reduction ratio of the reduction mechanism 11 in the low speed mode is 1 / 14, and the second reduction ratio of the reduction mechanism 11 in the high speed mode is 1 / 7.

[0095] The motor output indicating the output of the motor 8 is 1800W or more and 3000W or less.

[0096] The rated voltage of the battery pack 15 is 72V or more (maximum 80V or more). As described above, the first battery assembly section 71 and the second battery assembly section 72 are respectively arranged in the battery connection section 22. The first battery assembly section 71 is equipped with the first battery pack 151, and the second battery pack 152 is equipped with the second battery assembly section 72. The rated voltage of the first battery pack 151 and the rated voltage of the second battery pack 152 are equal to each other. The outer shape and size of the first battery pack 151 and the outer shape and size of the second battery pack 152 are equal to each other. That is, the first battery pack 151 and the second battery pack 152 are of the same type. The first battery pack 151 and the second battery pack 152 are connected in series. The rated voltage of each of the first battery pack 151 and the second battery pack 152 is 36V or more (maximum 40V or more). That is, at least two battery packs 15 having a rated voltage of 36 V or more (maximum 40 V or more) are mounted on the core drill 1A so that the total rated voltage of the battery packs 15 is 72 V or more (maximum 80 V or more).

[0097] <Effect>

[0098] As described above, in the present embodiment, the core drill 1A may include: a motor 8 having a stator 81 and a rotor 82, the rotor 82 rotating relative to the stator 81 around the motor rotation axis MX extending in the front-rear direction; a speed reduction mechanism 11 disposed at a position further forward than the stator 81 and reducing the speed of the rotation of the rotor 82; a spindle 12 at least part of which is disposed at a position further forward than the speed reduction mechanism 11 and is an output shaft that rotates by the rotational force of the rotor 82 transmitted via the speed reduction mechanism 11 when the core drill bit 19 is mounted; a battery mounting portion 7 to which the battery pack 15 is mounted; a motor housing portion 21 that houses the motor 8; a handle portion 24 at least part of which is disposed at a position further rearward than the motor housing portion 21 and on an extension line of the motor rotation axis MX; and a controller 10 that controls the motor 8. At least a part of the controller 10 may be disposed between the motor 8 and the handle portion 24 in the front-rear direction.

[0099] According to the above structure, the controller 10 can be effectively cooled. In addition, the handle 24 is arranged on the extension line of the motor rotation axis MX, and at least a part of the controller 10 is arranged between the motor 8 and the handle 24, so that the operator can easily operate the core drill 1A. For example, the weight balance of the core drill 1A is improved, so the core drill 1A is easy to operate.

[0100] In the present embodiment, the core drill 1A may include a controller housing portion 23 disposed between the motor housing portion 21 and the handle portion 24 . The controller 10 may be housed in the controller housing portion 23 .

[0101] According to the above configuration, the weight balance of the core drill 1A is improved, so that the core drill 1A is easy to operate.

[0102] In the present embodiment, an air inlet 25 may be provided in the controller housing portion 23 .

[0103] According to the above configuration, the controller 10 can be cooled efficiently.

[0104] [Second embodiment]

[0105] In the following description, the same reference numerals are given to the same or equivalent components as those in the above-mentioned embodiment, and the description of the components is simplified or omitted.

[0106] Fig. 9 This is a diagram of the core drill 1B according to the present embodiment as viewed from the right side. In the first embodiment, the battery pack 15 is mounted on the battery mounting portion 7 by sliding it from the left side to the right side of the battery mounting portion 7. Fig. 9As shown, the first battery pack 151 can be mounted on the first battery mounting portion 71 by sliding it from the rear side to the front. The second battery pack 152 can be mounted on the second battery mounting portion 72 by sliding it from the front side to the rear. Fig. 9 In the example shown, the first battery mounting portion 71 and the second battery mounting portion 72 are respectively arranged at the battery connecting portion 22. The first battery mounting portion 71 is arranged on the rear side of the second battery mounting portion 72.

[0107] Furthermore, the battery pack 15 can be mounted on the battery mounting portion 7 by sliding it from the right side to the left side of the battery mounting portion 7 .

[0108] [Third Embodiment]

[0109] In the following description, the same reference numerals are used to designate the same or equivalent components as those in the above-described embodiment, and the description of the components will be simplified or omitted.

[0110] Fig.10 This is a diagram of the core drill 1C according to the present embodiment as viewed from the right side. Fig.10 As shown, the first battery mounting portion 71 can be disposed on the battery connecting portion 22, and the second battery mounting portion 72 can be disposed on the motor housing portion 21. Fig.10 In the example shown, the second battery mounting portion 72 is disposed on the upper portion of the motor housing portion 21. Fig.10 In the example shown, the first battery pack 151 is mounted on the first battery mounting portion 71 by sliding it from the left side to the right side of the first battery mounting portion 71. The second battery pack 152 is mounted on the second battery mounting portion 72 by sliding it from the left side to the right side of the second battery mounting portion 72.

[0111] Furthermore, the first battery pack 151 can be mounted on the first battery mounting portion 71 by sliding it from the right side to the left side of the first battery mounting portion 71. The first battery pack 151 can be mounted on the first battery mounting portion 71 by sliding it from the front side to the rear side of the first battery mounting portion 71. The first battery pack 151 can be mounted on the first battery mounting portion 71 by sliding it from the rear side to the front side of the first battery mounting portion 71.

[0112] Furthermore, the second battery pack 152 can be mounted in the second battery mounting portion 72 by sliding it from the right side to the left side of the second battery mounting portion 72. The second battery pack 152 can be mounted in the second battery mounting portion 72 by sliding it from the front side to the rear side of the second battery mounting portion 72. The second battery pack 152 can be mounted in the second battery mounting portion 72 by sliding it from the rear side to the front side of the second battery mounting portion 72.

[0113] In addition, the second battery mounting portion 72 may be disposed on the left side of the motor housing portion 21 , or may be disposed on the right side of the motor housing portion 21 .

[0114] [Fourth Embodiment]

[0115] In the following description, the same reference numerals are used for the same or equivalent components as those in the above-described embodiment, and the description of the components is simplified or omitted.

[0116] Fig.11 This is a diagram showing the core drill 1D according to the present embodiment as viewed from the right side. Fig.11 As shown, the first battery mounting portion 71 and the second battery mounting portion 72 can be respectively disposed in the motor housing portion 21. Fig.11 In the example shown, the first battery mounting portion 71 and the second battery mounting portion 72 are respectively arranged on the upper portion of the motor housing portion 21. Fig.11 In the example shown, the first battery pack 151 is mounted on the first battery mounting portion 71 by sliding it from the left side to the right side of the first battery mounting portion 71. The second battery pack 152 is mounted on the second battery mounting portion 72 by sliding it from the left side to the right side of the second battery mounting portion 72.

[0117] The first battery pack 151 can be mounted on the first battery mounting portion 71 by sliding it from the right side to the left side of the first battery mounting portion 71. The first battery pack 151 can be mounted on the first battery mounting portion 71 by sliding it from the rear side to the front side.

[0118] The second battery pack 152 can be mounted in the second battery mounting portion 72 by sliding it from the right side to the left side of the second battery mounting portion 72. The second battery pack 152 can be mounted in the second battery mounting portion 72 by sliding it from the front side to the rear side of the second battery mounting portion 72.

[0119] The first battery mounting portion 71 may be disposed in the controller housing portion 23. For example, the first battery mounting portion 71 may be disposed above the controller housing portion 23. The first battery mounting portion 71 may be disposed on the left side of the controller housing portion 23 or on the right side of the controller housing portion 23.

[0120] [Fifth Embodiment]

[0121] In the following description, the same reference numerals are used for the same or equivalent components as those in the above-described embodiment, and the description of the components will be simplified or omitted.

[0122] Fig.12 This is a diagram showing the core drill 1E according to the present embodiment as viewed from above. Fig.12 As shown, the first battery mounting portion 71 and the second battery mounting portion 72 can be respectively disposed in the motor housing portion 21. Fig.12 In the example shown, the first battery mounting portion 71 is arranged at the left portion of the motor housing portion 21, and the second battery mounting portion 72 is arranged at the right portion of the motor housing portion 21. Fig.12 In the example shown, the first battery pack 151 is mounted on the first battery mounting portion 71 by sliding it forward from the rear side of the first battery mounting portion 71. The second battery pack 152 is mounted on the second battery mounting portion 72 by sliding it forward from the rear side of the second battery mounting portion 72.

[0123] Furthermore, the first battery pack 151 can be mounted on the first battery mounting portion 71 by sliding the first battery mounting portion 71 from the front side to the rear side.

[0124] Furthermore, the second battery pack 152 can be mounted on the second battery mounting portion 72 by sliding the second battery mounting portion 72 from the front side to the rear side.

[0125] [Sixth Embodiment]

[0126] In the following description, the same reference numerals are given to the same or equivalent components as those in the above-mentioned embodiment, and the description of the components is simplified or omitted.

[0127] Fig.13 This is a diagram showing the core drill 1F according to the present embodiment as viewed from above. Fig.13 As shown, the first battery mounting portion 71 and the second battery mounting portion 72 can be respectively disposed in the motor housing portion 21. Fig.13In the example shown, the first battery mounting portion 71 is arranged at the left portion of the motor housing portion 21, and the second battery mounting portion 72 is arranged at the right portion of the motor housing portion 21. Fig.13 In the example shown, the first battery pack 151 is mounted on the first battery mounting portion 71 by sliding downward from the upper side of the first battery mounting portion 71. The second battery pack 152 is mounted on the second battery mounting portion 72 by sliding downward from the upper side of the second battery mounting portion 72.

[0128] Furthermore, the first battery pack 151 can be mounted on the first battery mounting portion 71 by sliding it upward from the lower side of the first battery mounting portion 71 .

[0129] Furthermore, the second battery pack 152 can be mounted on the second battery mounting portion 72 by sliding it upward from the lower side of the second battery mounting portion 72 .

[0130] [Seventh Embodiment]

[0131] In the following description, the same reference numerals are given to the same or equivalent components as those in the above-mentioned embodiment, and the description of the components is simplified or omitted.

[0132] Fig.14 This is a diagram showing the core drill 1G according to the present embodiment as viewed from the right side. Fig.14 As shown, one battery mounting portion 700 may be provided at the battery connecting portion 22. The rated voltage of the battery pack 1500 mounted on the battery mounting portion 700 may be 80V or more.

[0133] [Eighth Embodiment]

[0134] In the following description, the same reference numerals are given to the same or equivalent components as those in the above-mentioned embodiment, and the description of the components is simplified or omitted.

[0135] Fig.15 This is a diagram showing the core drill 1H according to the present embodiment as viewed from the right side. Fig.15 As shown, the battery mounting portion 700 may be disposed on the upper portion of the motor housing portion 21. In addition, the battery mounting portion 700 may be disposed on the left portion of the motor housing portion 21 or on the right portion of the motor housing portion 21.

[0136] [Ninth Embodiment]

[0137] In the following description, the same reference numerals are used for the same or equivalent components as those in the above-mentioned embodiment, and the description of the components is simplified or omitted.

[0138] Fig.16 1J is a cross-sectional view showing the core drill 1J according to the present embodiment. In the above embodiment, the controller 10 is arranged on the extension line of the motor rotation axis MX. In addition, the controller 10 is arranged in the controller housing 23. Fig.16 As shown, the controller 10 may be disposed below the motor 8. The controller 10 may be housed in the battery connection portion 22. The air inlets 25 may be provided at the left and right portions of the battery connection portion 22, respectively.

[0139] [Tenth embodiment]

[0140] In the following description, the same reference numerals are given to the same or equivalent components as those in the above-mentioned embodiment, and the description of the components is simplified or omitted.

[0141] Fig.17 1 is a cross-sectional view showing a core drill 1K according to the present embodiment. Fig.17 As shown, the controller 10 may be accommodated in the lower handle portion 24B of the handle portion 24. The air inlet 25 may be provided at the left and right portions of the lower handle portion 24B, respectively. The air inlet 25 may be provided at the lower portion of the lower handle portion 24B.

[0142] [Eleventh Embodiment]

[0143] In the following description, the same reference numerals are given to the same or equivalent components as those in the above-mentioned embodiment, and the description of the components is simplified or omitted.

[0144] Fig.18 1 is a cross-sectional view showing a core drill 1L according to the present embodiment. Fig.18 As shown, the controller 10 may include a first controller 101 and a second controller 102. The first controller 101 may be accommodated in the rear handle portion 24C of the handle portion 24, and the second controller 102 may be arranged between the motor 8 and the handle portion 24 in the front-to-back direction. The second controller 102 may be accommodated in the controller accommodation portion 23.

[0145] [Twelfth Embodiment]

[0146] In the following description, the same reference numerals are given to the same or equivalent components as those in the above-mentioned embodiment, and the description of the components is simplified or omitted.

[0147] Fig.19 1 is a cross-sectional view showing a core drill 1M according to the present embodiment. Fig.19As shown, the controller 10 may include a first controller 101 and a second controller 102. The first controller 101 and the second controller 102 may be disposed between the motor 8 and the handle 24 in the front-to-back direction. The first controller 101 and the second controller 102 are disposed in the controller housing 23 in the front-to-back direction.

Claims

1. A core drill, characterized in that: The core drill has: A motor having a stator and a rotor, the rotor rotating relative to the stator around a rotation axis extending in the front-rear direction; a speed reduction mechanism disposed at a frontward position relative to the stator and configured to reduce the speed of rotation of the rotor; an output shaft, at least a portion of which is disposed forward of the reduction mechanism and rotated by the rotational force of the rotor transmitted via the reduction mechanism when the core drill bit is mounted thereon; A battery assembly section, which is used to assemble battery packs; a motor housing portion for housing the motor; a handle portion, at least a portion of which is disposed on an extension line of the rotating shaft at a position further rearward than the motor housing portion; as well as a controller for controlling the motor, At least a portion of the controller is disposed between the motor and the handle in the front-rear direction.

2. The core drill according to claim 1, characterized in that The core drill comprises: a controller housing portion disposed between the motor housing portion and the handle portion; The controller is accommodated in the controller accommodating portion.

3. The core drill according to claim 2, characterized in that: The controller housing portion is provided with an air inlet.

4. The core drill according to claim 2, characterized in that: The controller includes a first controller and a second controller. The first controller is accommodated in the handle portion. The second controller is configured between the motor and the handle.

5. The core drill according to claim 2, characterized in that: The controller includes a first controller and a second controller. The first controller and the second controller are respectively disposed between the motor and the handle.

Images