Core drill

Abstract

To improve the weight balance of a core drill.SOLUTION: A core drill includes: a motor having a stator and a rotor that rotates with respect to the stator; a deceleration mechanism configured to decelerate rotation of the rotor; an output shaft configured to be rotated by rotational force of the rotor transmitted via the deceleration mechanism, in a state where a core bit is attached to the output shaft; a first battery attachment portion to which a first battery pack is attached; and a second battery attachment portion which is connected in series to the first battery attachment portion and to which a second battery pack is attached. Respective rated voltages of the first battery pack and the second battery pack are equal to or higher than 40 V.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a core drill. [Background technology]

[0002] In the technical field related to core drills, core drills such as those disclosed in Patent Documents 1, 2, and 3 are known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent No. 010710172 [Patent Document 2] US Patent Application Publication No. 2022 / 0154534 [Patent Document 3] US Patent Application Publication No. 2022 / 0258256 Summary of the Invention [Problem to be solved by the invention]

[0004] When the power source of the core drill is a battery pack, the weight balance of the core drill may become worse depending on the shape of the battery pack.

[0005] The technology disclosed in this specification aims to improve the weight balance of a core drill. [Means for solving the problem]

[0006] This specification discloses a core drill. The core drill may include a motor having a stator and a rotor rotating relative to the stator, a speed reduction mechanism for reducing the rotation of the rotor, an output shaft that rotates by the rotational force of the rotor transmitted via the speed reduction mechanism with a core bit attached, a first battery mounting section to which a first battery pack is attached, and a second battery mounting section that is connected in series with the first battery mounting section and to which a second battery pack is attached. The rated voltage of each of the first battery pack and the second battery pack may be 40V or more. Effect of the Invention

[0007] According to the technique disclosed in this specification, the weight balance of the core drill is improved. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a core drill according to a first embodiment, viewed from the upper right front. [Diagram 2] FIG. 2 is a view of the core drill according to the first embodiment as viewed from above. [Diagram 3] FIG. 3 is a front view of the core drill according to the first embodiment. [Figure 4] FIG. 4 is a view of the core drill according to the first embodiment as viewed from the right. [Diagram 5] FIG. 5 is a cross-sectional view showing the core drill according to the first embodiment. [Figure 6] FIG. 6 is a view of the motor according to the first embodiment as viewed from the right. [Figure 7] FIG. 7 is a view of the reduction mechanism according to the first embodiment as viewed from above. [Figure 8] FIG. 8 is a view showing a state in which a core bit is attached to the spindle of the core drill according to the first embodiment. [Figure 9] FIG. 9 is a view of the core drill according to the second embodiment as viewed from the right. [Figure 10] FIG. 10 is a view of the core drill according to the third embodiment as viewed from the right. [Figure 11] FIG. 11 is a view of the core drill according to the fourth embodiment as viewed from the right. [Figure 12] FIG. 12 is a view of the core drill according to the fifth embodiment as viewed from above. [Figure 13] FIG. 13 is a view of the core drill according to the sixth embodiment as viewed from above. [Figure 14] FIG. 14 is a view of the core drill according to the seventh embodiment as viewed from the right. [Figure 15] FIG. 15 is a view of the core drill according to the eighth embodiment as viewed from the right. [Figure 16] FIG. 16 is a cross-sectional view showing a core drill according to a ninth embodiment. [Figure 17] FIG. 17 is a cross-sectional view showing a core drill according to the tenth embodiment. [Figure 18] FIG. 18 is a cross-sectional view showing a core drill according to the eleventh embodiment. [Figure 19] FIG. 19 is a cross-sectional view showing a core drill according to the twelfth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In one or more embodiments, the core drill may include a motor having a stator and a rotor rotating relative to the stator, a speed reduction mechanism for reducing the rotation of the rotor, an output shaft that rotates by the rotational force of the rotor transmitted via the speed reduction mechanism with the core bit attached, a first battery mounting section to which the first battery pack is attached, and a second battery mounting section connected in series with the first battery mounting section to which the second battery pack is attached. The rated voltage of each of the first battery pack and the second battery pack may be 40 V or more.

[0010] In the above configuration, by combining a plurality of battery packs, excessive increase in size of one battery pack is suppressed, and the weight balance of the core drill is improved. In addition, since the rated voltage of each of the first battery pack and the second battery pack is 40V or more, the motor can have a high torque.

[0011] In one or more embodiments, the reduction mechanism may be disposed forward of the stator. At least a portion of the output shaft may be disposed forward of the reduction mechanism. The core drill may include a motor housing that houses the motor, and a battery connection portion disposed below the motor housing. Each of the first battery mounting portion and the second battery mounting portion may be disposed in the battery connection portion.

[0012] With the above configuration, the weight balance of the core drill is improved.

[0013] In one or more embodiments, the reduction mechanism may be disposed forward of the stator. At least a portion of the output shaft may be disposed forward of the reduction mechanism. The core drill may include a motor housing that houses the motor, and a battery connection portion disposed below the motor housing. The first battery mounting portion may be disposed in the battery connection portion, and the second battery mounting portion may be disposed in the motor housing.

[0014] With the above configuration, the weight balance of the core drill is improved.

[0015] In one or more embodiments, the second battery mounting portion may be located above the motor housing portion.

[0016] With the above configuration, the weight balance of the core drill is improved.

[0017] In one or more embodiments, the reduction mechanism may be disposed forward of the stator. At least a portion of the output shaft may be disposed forward of the reduction mechanism. The core drill may include a motor housing that houses the motor, and a battery connection portion disposed below the motor housing. Each of the first battery mounting portion and the second battery mounting portion may be disposed in the motor housing.

[0018] With the above configuration, the weight balance of the core drill is improved.

[0019] In one or more embodiments, the first battery mounting portion may be located on a left side of the motor housing portion and the second battery mounting portion may be located on a right side of the motor housing portion.

[0020] With the above configuration, the weight balance of the core drill is improved.

[0021] In one or more embodiments, the reduction mechanism may be disposed forward of the stator. At least a portion of the output shaft may be disposed forward of the reduction mechanism. The core drill may include a motor housing that houses the motor, a controller that is disposed rearward of the motor and controls the motor, and a controller housing that is disposed rearward of the motor housing and houses the controller. The first battery mounting portion may be disposed in the controller housing, and the second battery mounting portion may be disposed in the motor housing.

[0022] With the above configuration, the weight balance of the core drill is improved.

[0023] Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiment. The components of the embodiments described below can be appropriately combined. In addition, some components may not be used.

[0024] In the embodiment, the positional relationship of each part will be described using the terms "left", "right", "front", "rear", "upper", and "lower". These terms indicate relative positions or directions based on the center of the core drill. The left-right direction, the front-rear direction, and the up-down direction are perpendicular to each other.

[0025] [First embodiment] A first embodiment will be described.

[0026] <Core drill> FIG. 1 is a perspective view of the core drill 1A according to the present embodiment from the upper right front. FIG. 2 is a view of the core drill 1A according to the present embodiment seen from above. FIG. 3 is a view of the core drill 1A according to the present embodiment seen from the front. FIG. 4 is a view of the core drill 1A according to the present embodiment seen from the right. FIG. 5 is a cross-sectional view of the core drill 1A according to the present embodiment.

[0027] In this embodiment, the core drill 1A is a rechargeable diamond core drill.

[0028] The core drill 1A comprises a main body housing 2, a motor case 3, a gear case 4, a gear housing 5, a side handle 6, a battery mounting section 7, a motor 8, a fan 9, a controller 10, a reduction mechanism 11, a spindle 12, a trigger lever 13, and a water supply tube 14.

[0029] The main body housing 2 is made of synthetic resin. The main body housing 2 includes a left main body housing 2L and a right main body housing 2R. The right main body housing 2R is disposed to the right of the left main body housing 2L. The left main body housing 2L and the right main body housing 2R form a pair of half-split housings. The left main body housing 2L and the right main body housing 2R are fixed together by a plurality of screws 2S.

[0030] The main body housing 2 has a motor accommodating section 21, a battery connection section 22, a controller accommodating section 23, and a grip section 24.

[0031] The motor accommodating portion 21 accommodates the motor case 3. The motor case 3 accommodates the motor 8. The motor accommodating portion 21 accommodates the motor 8 via the motor case 3.

[0032] The battery connection portion 22 holds the battery mounting portion 7. The battery connection portion 22 is disposed below the motor accommodating portion 21.

[0033] The controller accommodating portion 23 accommodates the controller 10. The controller accommodating portion 23 is disposed behind the motor accommodating portion 21.

[0034] The grip portion 24 is held by an operator. The grip portion 24 is disposed rearward of the motor accommodating portion 21. The grip portion 24 is disposed rearward of the controller accommodating portion 23. In the front-rear direction, the controller accommodating portion 23 is disposed between the motor accommodating portion 21 and the grip portion 24.

[0035] The grip portion 24 includes an upper grip portion 24A extending rearward from an upper portion of the controller housing portion 23, a lower grip portion 24B extending rearward from a lower portion of the controller housing portion 23, and a rear grip portion 24C connecting a rear portion of the upper grip portion 24A and a rear portion of the lower grip portion 24B. The trigger lever 13 is disposed on an upper portion of the rear grip portion 24C.

[0036] The gear case 4 houses at least a part of the reduction gear mechanism 11. The gear case 4 is connected to a front part of the motor accommodating section 21. The front part of the motor case 3 is disposed between the front part of the motor accommodating section 21 and the rear part of the gear case 4. The gear case 4 is connected to the front part of the motor accommodating section 21 via the motor case 3. The front part of the motor case 3 and the rear part of the gear case 4 are fixed together by a plurality of screws 4S.

[0037] The gear housing 5 accommodates at least a part of the reduction gear mechanism 11. The gear housing 5 accommodates the spindle 12. The gear housing 5 is connected to a front part of the gear case 4. The front part of the gear case 4 and the rear part of the gear housing 5 are fixed together by a plurality of screws 5S.

[0038] The side handle 6 is held by an operator. The side handle 6 is fixed to the left of the gear housing 5. The side handle 6 protrudes leftward from the left part of the gear housing 5.

[0039] The battery mounting section 7 holds the battery pack 15. The battery mounting section 7 is disposed below the battery connection section 22. The battery mounting section 7 includes a terminal block that is connected to the battery pack 15. The battery pack 15 is mounted in the battery mounting section 7. The battery pack 15 is attached to and detached from the battery mounting section 7.

[0040] In this embodiment, two battery mounting sections 7 are provided. The battery mounting section 7 includes a first battery mounting section 71 and a second battery mounting section 72. The structure and size of the terminal block of the first battery mounting section 71 and the structure and size of the terminal block of the second battery mounting section 72 are equal to each other. The first battery mounting section 71 and the second battery mounting section 72 are connected in series.

[0041] The first battery mounting section 71 and the second battery mounting section 72 are disposed adjacent to each other in the front-rear direction. The first battery mounting section 71 is disposed rearward of the second battery mounting section 72. The battery pack 15 includes a first battery pack 151 mounted in the first battery mounting section 71 and a second battery pack 152 mounted in the second battery mounting section 72.

[0042] 3, the battery pack 15 is attached to the battery mounting section 7 by sliding it from the left side to the right side of the battery mounting section 7. The battery pack 15 is attached to the battery mounting section 7 by a sliding method.

[0043] The first battery pack 151 is attached to the first battery attachment section 71 by sliding it from the left side to the right side of the first battery attachment section 71. The first battery attachment section 71 has a terminal. When the first battery pack 151 is attached to the first battery attachment section 71, a connection terminal of the first battery pack 151 and a terminal terminal of the first battery attachment section 71 are connected. The first battery pack 151 is removed from the first battery attachment section 71 by sliding it leftward from the first battery attachment section 71. The first battery pack 151 is attached to or detached from the first battery attachment section 71.

[0044] The second battery pack 152 is attached to the second battery attachment section 72 by sliding from the left side to the right side of the second battery attachment section 72. The second battery attachment section 72 has a terminal. By attaching the second battery pack 152 to the second battery attachment section 72, the connection terminal of the second battery pack 152 and the terminal terminal of the second battery attachment section 72 are connected. The second battery pack 152 is removed from the second battery attachment section 72 by sliding leftward from the second battery attachment section 72. The second battery pack 152 is attached to or detached from the second battery attachment section 72.

[0045] The battery pack 15 functions as a power source for the core drill 1A. The battery pack 15 includes a secondary battery. In this embodiment, the battery pack 15 includes a rechargeable lithium-ion battery. When attached to the battery attachment section 7, the battery pack 15 can supply power 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 each of the first battery pack 151 and the second battery pack 152. The controller 10 operates based on the power supplied from each of the first battery pack 151 and the second battery pack 152.

[0046] The motor 8 functions as a power source for the core drill 1A. The motor 8 is an inner rotor type DC brushless motor. The motor 8 is accommodated in a motor case 3. The motor case 3 is accommodated in a motor accommodating section 21 of the main body housing 2. The motor 8 is accommodated in the motor accommodating section 21 via the motor case 3.

[0047] 6 is a view of the motor 8 according to this embodiment as viewed from the right. The motor 8 has 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 about a motor rotation axis MX extending in the front-rear direction.

[0048] The stator 81 includes a stator core 84 having a circular 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 wound around each of 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.

[0049] The rotor 82 rotates about a motor rotation axis MX. The rotor 82 has a rotor core 87 and a rotor magnet 88 fixed to the rotor core 87.

[0050] A sensor board (not shown) is fixed to the insulator 85. The sensor board supports a rotation detection element that detects the rotational position of the rotor 82. The rotation detection element detects the position of the rotor magnet 88, thereby detecting the rotational position of the rotor 82.

[0051] The rotor shaft 83 is fixed to the rotor core 87. The rotor 82 and the rotor shaft 83 rotate together about the motor rotation axis MX.

[0052] The rotor shaft 83 is rotatably supported by each of the rotor bearing 51 and the rotor bearing 52. The rotor bearing 51 rotatably supports a rear portion of the rotor shaft 83 that protrudes rearward beyond the rear end surface of the rotor 82. The rotor bearing 52 rotatably supports a front portion of the rotor shaft 83 that protrudes forward beyond the front end surface of the rotor 82. The rotor bearing 51 is held by the motor case 3. The rotor bearing 52 is held by a motor bracket 16 fixed to the rear portion of the gear case 4.

[0053] The fan 9 generates an airflow for cooling the motor 8 and the controller 10. The fan 9 is disposed in front of the stator 81. The fan 9 is fixed to the front part of the rotor shaft 83. The fan 9 is disposed between the stator 81 and the rotor bearing 52. The fan 9 and the rotor shaft 83 rotate together.

[0054] An intake port 25 is provided at each of the left and right parts of the controller accommodating section 23. An exhaust port 26 is provided at each of the left and right parts of the front part of the motor case 3. When the fan 9 rotates, air from the external space of the main body housing 2 flows into the internal space of the controller accommodating section 23 through the intake port 25. The air that flows into the internal space of the controller accommodating section 23 cools the controller 10 by circulating through the internal space of the controller accommodating section 23. When the fan 9 rotates, the air that flows through the internal space of the controller accommodating section 23 flows into the internal space of the motor case 3 through an air vent provided at the rear of the motor case 3. When the fan 9 rotates, the air that flows into the internal space of the motor case 3 cools the motor 8 by circulating through the internal space of the motor case 3. When the fan 9 rotates, at least a part of the air that flows through the internal space of the motor case 3 flows out through the exhaust port 26 to the external space of the motor case 3.

[0055] The controller 10 outputs a control signal to control 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 central processing unit (CPU), a non-volatile memory such as a read only memory (ROM) or storage, a volatile memory such as a random access memory (RAM), a field effect transistor (FET), and a resistor. The controller 10 is accommodated in a controller accommodating section 23.

[0056] The controller 10 is disposed behind the motor 8. At least a portion of the controller 10 is disposed on an extension of the motor rotation shaft MX. That is, at least a portion of the controller 10 and the motor rotation shaft MX are disposed at the same position in both the up-down direction and the left-right direction.

[0057] The grip portion 24 is disposed rearward of the controller 10. At least a portion of the grip portion 24 is disposed rearward of the motor housing portion 21 and on an extension of the motor rotation axis MX. That is, at least a portion of the grip portion 24 and the motor rotation axis MX are disposed at the same position in each of the up-down direction and the left-right direction. In this embodiment, at least a portion of the rear grip portion 24C and the motor rotation axis MX are disposed at the same position in each of the up-down direction and the left-right direction. In this embodiment, at least a portion of the trigger lever 13 and the motor rotation axis MX are disposed at the same position in each of the up-down direction and the left-right direction.

[0058] In the front-rear direction, at least a portion of the controller 10 is disposed between the motor 8 and the grip portion 24.

[0059] The reduction mechanism 11 transmits the rotational force of the motor 8 to the spindle 12. The reduction mechanism 11 connects the rotor shaft 83 and the spindle 12. The reduction mechanism 11 reduces the rotation of the rotor 82 and transmits it to the spindle 12. The reduction mechanism 11 rotates the spindle 12 at a rotational speed lower than the rotational speed of the rotor shaft 83. The reduction mechanism 11 reduces the rotation of the rotor 82 at a predetermined reduction ratio. The reduction mechanism 11 is disposed forward of the stator 81.

[0060] The gear 30 is fixed to the front end of the rotor shaft 83. The rotor shaft 83 is connected to the reduction mechanism 11 via the gear 30.

[0061] 7 is a view of the reduction gear mechanism 11 according to this embodiment as viewed from above. The reduction gear mechanism 11 has an intermediate shaft 31, a gear 32 fixed to a rear portion of the intermediate shaft 31, a gear 33 fixed to a front portion of the intermediate shaft 31, and a gear 34 fixed to the intermediate shaft 31 on the front side of the gear 33. The reduction gear mechanism 11 also has a gear 35 fixed to a rear portion of the spindle 12, and a gear 36 supported by the spindle 12 on the front side of the gear 35. The intermediate shaft 31 is disposed to the left of the rotor shaft 83 and the spindle 12. The gear 30 and the gear 32 mesh with each other. The gear 33 and the gear 35 can mesh with each other. The gear 34 and the gear 36 can mesh with each other.

[0062] When the rotor shaft 83 rotates, the intermediate shaft 31 connected to the rotor shaft 83 via the gears 30 and 32 rotates. When the intermediate shaft 31 rotates, the spindle 12 connected to the intermediate shaft 31 via the gears 33, 35 and the gears 34, 36 rotates.

[0063] The reduction gear mechanism 11 can change the reduction ratio. The reduction gear ratio of the reduction gear mechanism 11 is changed by operating the speed change lever 17 provided at the bottom of the gear housing 5. The change ring 37 between the gears 35 and 36 moves in the front-rear direction by operating the speed change lever 17. The change ring 37 moves in the front-rear direction by moving the change ring 37, thereby changing the reduction gear ratio of the reduction gear mechanism 11. When the reduction gear ratio of the reduction gear mechanism 11 is changed to the first reduction gear ratio, the spindle 12 rotates at a first speed (low speed). When the reduction gear ratio of the reduction gear mechanism 11 is changed to the second reduction gear ratio, the spindle 12 rotates at a 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 gear ratio is appropriately referred to as a low speed mode, and the state in which the reduction gear mechanism 11 is in the second reduction gear ratio is appropriately referred to as a high speed mode.

[0064] The spindle 12 is an output shaft that rotates by the rotational force of the rotor 82 transmitted via the reduction mechanism 11 with the core bit attached. The spindle 12 is disposed forward of the rotor shaft 83. At least a portion of the spindle 12 is disposed forward of the reduction mechanism 11.

[0065] The spindle 12 is rotatable about an output rotation axis AX extending in the front-rear direction. The output rotation axis AX and the motor rotation axis MX do not have to coincide with each other. In the embodiment, the output rotation axis AX and the motor rotation axis MX are parallel to each other. The spindle 12 is rotatably supported by each of a spindle bearing 53 and a spindle bearing 54. The spindle bearing 53 is held by the gear housing 5. The spindle bearing 54 is held by the gear case 4.

[0066] 8 is a diagram showing a state in which a core bit 19 is attached to the spindle 12 of the core drill 1A according to this embodiment. When the spindle 12 rotates due to the rotational force generated by the motor 8, the core bit 19 attached to the front end of the spindle 12 rotates together with the spindle 12.

[0067] The trigger lever 13 is operated by an operator to drive the motor 8. The trigger lever 13 protrudes forward from the front of the upper part of the rear grip portion 24C. A trigger switch 18 is disposed inside the rear grip portion 24C. The trigger lever 13 is operated by an operator to move it rearward. When the trigger lever 13 is operated to move rearward, an operation signal for driving the motor 8 is transmitted from the trigger switch 18 to the controller 10. Based on the operation signal from the trigger switch 18, the controller 10 supplies a drive current for driving the motor 8 to the motor 8. When the operation of the trigger lever 13 is released, the driving of the motor 8 stops.

[0068] The water supply tube 14 supplies water to the core bit 19. The water supply tube 14 is connected to the gear housing 5. The water supplied from the water supply tube 14 to the inside of the gear housing 5 passes through the inside of the spindle 12, and then is supplied to the core bit 19.

[0069] [Specifications] As shown in FIG. 6, the stator outer diameter D indicating the outer diameter of the stator core 84 is 75 mm or more. The stator outer diameter D is the dimension of the stator core 84 in a direction perpendicular to the motor rotation axis MX. The upper limit of the stator outer diameter D is not particularly limited, but may be 120 mm. That is, the stator outer diameter D may be 75 mm or more and 120 mm or less. The stator outer diameter D may be 80 mm or more, 85 mm or more, 90 mm or more, 95 mm or more, 100 mm or more, 105 mm or more, or 110 mm or more. In this embodiment, the stator outer diameter D is 80 mm.

[0070] The stator length L, which indicates the dimension in the axial direction of the stator core 84, is 30 mm or more. The stator length L is the dimension of the stator core 84 in a direction parallel to the motor rotation axis MX. The upper limit of the stator length L is not particularly limited, but may be 65 mm. That is, the stator length L may be 30 mm or more and 65 mm or less. The stator length L may be 35 mm or more, 40 mm or more, 45 mm or more, 50 mm or more, or 55 mm or more. In this embodiment, the stator length L is 50 mm.

[0071] As shown in FIG. 7, the hole drilling diameter H, which indicates the outer diameter of the tip (front end) of the core bit 19, is 155 mm or more. The upper limit of the hole drilling diameter H is not particularly limited, but may be 200 mm. That is, the hole drilling diameter H may be 155 mm or more and 200 mm or less. The hole drilling diameter H may be 160 mm or more, 165 mm or more, 170 mm or more, 175 mm or more, 180 mm or more, 185 mm or more, or 190 mm or more. In this embodiment, the hole drilling diameter H is 160 mm.

[0072] The reduction ratio of the reduction mechanism 11 may be 1 / 16 or more and 1 / 5 or less. For example, the first reduction ratio of the reduction mechanism 11 in the low speed mode may be 1 / 16 or more and 1 / 12 or less. The second reduction ratio of the reduction mechanism 11 in the high speed mode may be 1 / 9 or more and 1 / 5 or less. 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.

[0073] The motor output indicating the output of the motor 8 is 1800W or more and 3000W or less.

[0074] The rated voltage of the battery pack 15 is 72V or more (maximum 80V or more). As described above, each of the first battery mounting section 71 and the second battery mounting section 72 is disposed in the battery connection section 22. The first battery pack 151 is mounted in the first battery mounting section 71, and the second battery pack 152 is mounted in the second battery mounting 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 dimensions of the first battery pack 151 and the outer shape and dimensions 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 with a rated voltage of 36V or more (maximum 40V or more) are attached to the core drill 1A so that the sum of the rated voltages of the battery packs 15 is 72V or more (maximum 80V or more).

[0075] <Effects> As described above, in this embodiment, the core drill 1A may include the motor 8 having the stator 81 and the rotor 82 rotating relative to the stator 81, the speed reducing mechanism 11 for reducing the rotation of the rotor 82, the spindle 12 which is an output shaft that rotates by the rotational force of the rotor 82 transmitted via the speed reducing mechanism 11 with the core bit 19 attached, the first battery mounting section 71 to which the first battery pack 151 is attached, and the second battery mounting section 72 which is connected in series with the first battery mounting section 71 and to which the second battery pack 152 is attached. The rated voltage of each of the first battery pack 151 and the second battery pack 152 may be 40V or more.

[0076] In the above configuration, by combining a plurality of battery packs 15, excessive increase in size of one battery pack 15 is suppressed, and the weight balance of the core drill 1A is improved. In addition, since the rated voltage of each of the first battery pack 151 and the second battery pack 152 is 40V or more, the motor 8 can have a high torque.

[0077] In the present embodiment, the reduction mechanism 11 may be disposed forward of the stator 81. At least a portion of the spindle 12 may be disposed forward of the reduction mechanism 11. The core drill 1A may include a motor accommodating portion 21 that accommodates the motor 8, and a battery connection portion 22 disposed below the motor accommodating portion 21. Each of the first battery mounting portion 71 and the second battery mounting portion 72 may be disposed in the battery connection portion 22.

[0078] With the above configuration, the weight balance of the core drill 1A is improved.

[0079] [Second embodiment] A second embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0080] FIG. 9 is a view of the core drill 1B according to this embodiment as viewed from the right. In the above-mentioned first embodiment, the battery pack 15 is attached to the battery mounting section 7 by sliding from the left side of the battery mounting section 7 to the right. As shown in FIG. 9, the first battery pack 151 may be attached to the first battery mounting section 71 by sliding from the rear side of the first battery mounting section 71 to the front. The second battery pack 152 may be attached to the second battery mounting section 72 by sliding from the front side of the second battery mounting section 72 to the rear. In the example shown in FIG. 9, each of the first battery mounting section 71 and the second battery mounting section 72 is disposed in the battery connection section 22. The first battery mounting section 71 is disposed on the rear side of the second battery mounting section 72.

[0081] The battery pack 15 may be attached to the battery attachment section 7 by sliding it from the right side of the battery attachment section 7 to the left.

[0082] [Third embodiment] A third embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0083] FIG. 10 is a view of the core drill 1C according to this embodiment as viewed from the right. As shown in FIG. 10, the first battery mounting section 71 may be disposed in the battery connection section 22, and the second battery mounting section 72 may be disposed in the motor housing section 21. In the example shown in FIG. 10, the second battery mounting section 72 is disposed in the upper part of the motor housing section 21. In the example shown in FIG. 10, the first battery pack 151 is mounted on the first battery mounting section 71 by sliding from the left side to the right side of the first battery mounting section 71. The second battery pack 152 is mounted on the second battery mounting section 72 by sliding from the left side to the right side of the second battery mounting section 72.

[0084] The first battery pack 151 may be attached to the first battery mounting section 71 by sliding from the right side to the left of the first battery mounting section 71. The first battery pack 151 may be attached to the first battery mounting section 71 by sliding from the front side of the first battery mounting section 71 to the rear. The first battery pack 151 may be attached to the first battery mounting section 71 by sliding from the rear side of the first battery mounting section 71 to the front.

[0085] The second battery pack 152 may be attached to the second battery mounting section 72 by sliding from the right side to the left of the second battery mounting section 72. The second battery pack 152 may be attached to the second battery mounting section 72 by sliding from the front side of the second battery mounting section 72 to the rear. The second battery pack 152 may be attached to the second battery mounting section 72 by sliding from the rear side of the second battery mounting section 72 to the front.

[0086] The second battery mounting section 72 may be disposed on the left side of the motor accommodating section 21 or on the right side of the motor accommodating section 21.

[0087] [Fourth embodiment] A fourth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0088] FIG. 11 is a view of the core drill 1D according to this embodiment as viewed from the right. As shown in FIG. 11, each of the first battery mounting section 71 and the second battery mounting section 72 may be disposed in the motor housing section 21. In the example shown in FIG. 11, each of the first battery mounting section 71 and the second battery mounting section 72 is disposed in the upper part of the motor housing section 21. In the example shown in FIG. 11, the first battery pack 151 is mounted on the first battery mounting section 71 by sliding from the left side to the right side of the first battery mounting section 71. The second battery pack 152 is mounted on the second battery mounting section 72 by sliding from the left side to the right side of the second battery mounting section 72.

[0089] The first battery pack 151 may be attached to 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 may be attached to the first battery mounting portion 71 by sliding it from the rear side of the first battery mounting portion 71 to the front.

[0090] The second battery pack 152 may be attached to the second battery mounting section 72 by sliding from the right side to the left side of the second battery mounting section 72. The second battery pack 152 may be attached to the second battery mounting section 72 by sliding from the front side of the second battery mounting section 72 to the rear.

[0091] The first battery attachment section 71 may be disposed in the controller accommodating section 23. The first battery attachment section 71 may be disposed, for example, in the upper part of the controller accommodating section 23. The first battery attachment section 71 may be disposed in the left part of the controller accommodating section 23, or in the right part of the controller accommodating section 23.

[0092] [Fifth embodiment] A fifth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0093] FIG. 12 is a view of the core drill 1E according to the present embodiment as viewed from above. As shown in FIG. 12, each of the first battery mounting section 71 and the second battery mounting section 72 may be disposed in the motor housing section 21. In the example shown in FIG. 12, the first battery mounting section 71 is disposed in the left part of the motor housing section 21, and the second battery mounting section 72 is disposed in the right part of the motor housing section 21. In the example shown in FIG. 12, the first battery pack 151 is mounted on the first battery mounting section 71 by sliding forward from the rear side of the first battery mounting section 71. The second battery pack 152 is mounted on the second battery mounting section 72 by sliding forward from the rear side of the second battery mounting section 72.

[0094] The first battery pack 151 may be attached to the first battery attachment portion 71 by sliding it from the front side of the first battery attachment portion 71 to the rear side.

[0095] The second battery pack 152 may be attached to the second battery attachment section 72 by sliding it from the front side of the second battery attachment section 72 to the rear.

[0096] [Sixth embodiment] A sixth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiments are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0097] FIG. 13 is a view of the core drill 1F according to this embodiment as seen from above. As shown in FIG. 13, each of the first battery mounting section 71 and the second battery mounting section 72 may be disposed in the motor housing section 21. In the example shown in FIG. 13, the first battery mounting section 71 is disposed in the left part of the motor housing section 21, and the second battery mounting section 72 is disposed in the right part of the motor housing section 21. In the example shown in FIG. 13, the first battery pack 151 is mounted on the first battery mounting section 71 by sliding downward from the upper side of the first battery mounting section 71. The second battery pack 152 is mounted on the second battery mounting section 72 by sliding downward from the upper side of the second battery mounting section 72.

[0098] The first battery pack 151 may be attached to the first battery attachment portion 71 by sliding it upward from the lower side of the first battery attachment portion 71.

[0099] The second battery pack 152 may be attached to the second battery attachment section 72 by sliding upward from the lower side of the second battery attachment section 72.

[0100] [Seventh embodiment] A seventh embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0101] Fig. 14 is a view of the core drill 1G according to this embodiment as viewed from the right. As shown in Fig. 14, one battery mounting section 700 may be provided in the battery connection section 22. The rated voltage of the battery pack 1500 mounted in the battery mounting section 700 may be 80V or more.

[0102] [Eighth embodiment] An eighth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiments are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0103] Fig. 15 is a view of the core drill 1H according to this embodiment as viewed from the right. As shown in Fig. 15, the battery mounting section 700 may be disposed on the upper part of the motor accommodating section 21. The battery mounting section 700 may be disposed on the left part of the motor accommodating section 21 or on the right part of the motor accommodating section 21.

[0104] [Ninth embodiment] A ninth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0105] Fig. 16 is a cross-sectional view showing a core drill 1J according to this embodiment. In the above-described embodiment, the controller 10 is arranged on an extension of the motor rotation axis MX. The controller 10 is also arranged in the controller housing 23. As shown in Fig. 16, the controller 10 may be arranged below the motor 8. The controller 10 may be housed in the battery connector 22. An air intake 25 may be provided in each of the left and right parts of the battery connector 22.

[0106] [Tenth embodiment] A tenth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiments are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0107] Fig. 17 is a cross-sectional view showing a core drill 1K according to this embodiment. As shown in Fig. 17, the controller 10 may be housed in the lower grip portion 24B of the grip portion 24. An air intake 25 may be provided in each of the left and right portions of the lower grip portion 24B. An air intake 25 may be provided in a lower portion of the lower grip portion 24B.

[0108] [Eleventh embodiment] An eleventh embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiments are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0109] Fig. 18 is a cross-sectional view showing a core drill 1L according to this embodiment. As shown in Fig. 18, the controller 10 may include a first controller 101 and a second controller 102. The first controller 101 may be accommodated in the rear grip portion 24C of the grip portion 24, and the second controller 102 may be disposed between the motor 8 and the grip portion 24 in the front-rear direction. The second controller 102 may be accommodated in the controller accommodating portion 23.

[0110] [Twelfth embodiment] A twelfth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0111] Fig. 19 is a cross-sectional view showing a core drill 1M according to this embodiment. As shown in Fig. 19, the controller 10 may include a first controller 101 and a second controller 102. Each of the first controller 101 and the second controller 102 may be disposed between the motor 8 and the grip unit 24 in the front-rear direction. The first controller 101 and the second controller 102 are disposed in the controller housing unit 23 in the front-rear direction. [Explanation of symbols]

[0112]

[0043] 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 housing, 2L...left main body housing, 2R...right main body housing, 2S...screw, 3...motor case, 4...gear case, 4S...screw, 5...gear housing, 5S...screw, 6...side handle, 7...battery mounting section, 8...motor, 9...fan, 10...controller, 11...reduction mechanism, 12...spindle, 13...trigger lever, 14...water supply tube, 15...battery pack, 16...motor bracket, 17...speed change lever, 18...trigger switch, 19...core bit, 21...motor housing, 22...battery connection section, 23...controller housing, 24...grip section, 24A...upper g Lip portion, 24B...lower grip portion, 24C...rear grip portion, 25...intake port, 26...exhaust port, 30...gear, 31...intermediate shaft, 32...gear, 33...gear, 34...gear, 35...gear, 36...gear, 37...change ring, 51...rotor bearing, 52...rotor bearing, 53...spindle bearing, 54...spindle bearing, 71...first battery mounting portion, 72...second battery mounting portion, 81...stator, 82...rotor, 83...rotor Shaft, 84...stator core, 85...insulator, 86...coil, 87...rotor core, 88...rotor magnet, 89...busbar unit, 101...first controller, 102...second controller, 151...first battery pack, 152...second battery pack, 700...battery mounting section, 1500...battery pack, AX...output rotating shaft, D...stator outer diameter, L...stator length, H...hole diameter, MX...motor rotating shaft.

Claims

1. A motor having a stator and a rotor that rotates relative to the stator, A reduction mechanism for reducing the rotation of the rotor, With the core bit installed, the output shaft rotates due to the rotational force of the rotor transmitted via the reduction mechanism, The first battery mounting section into which the first battery pack is installed, The device comprises a second battery mounting section connected in series with the first battery mounting section, and a second battery pack being mounted therein. The rated voltages of the first battery pack and the second battery pack are 40V or higher. Core drill.

2. The reduction mechanism is positioned in front of the stator, At least a portion of the output shaft is positioned in front of the reduction mechanism. A motor housing section for housing the motor, It comprises a battery connection section located below the motor housing section, The first battery mounting section and the second battery mounting section are each positioned in the battery connection section. The core drill according to claim 1.

3. The reduction mechanism is positioned in front of the stator, At least a portion of the output shaft is positioned in front of the reduction mechanism. A motor housing section for housing the motor, It comprises a battery connection section located below the motor housing section, The first battery mounting section is located at the battery connection section. The second battery mounting section is located in the motor housing section. The core drill according to claim 1.

4. The second battery mounting section is located above the motor housing section. The core drill according to claim 3.

5. The reduction mechanism is positioned in front of the stator, At least a portion of the output shaft is positioned in front of the reduction mechanism. A motor housing section for housing the motor, It comprises a battery connection section located below the motor housing section, The first battery mounting section and the second battery mounting section are each located in the motor housing section. The core drill according to claim 1.

6. The first battery mounting section is located to the left of the motor housing section. The second battery mounting section is located to the right of the motor housing section. The core drill according to claim 3.

7. The reduction mechanism is positioned in front of the stator, At least a portion of the output shaft is positioned in front of the reduction mechanism. A motor housing section for housing the motor, A controller, positioned behind the aforementioned motor, controls the aforementioned motor. The system comprises a controller housing located behind the motor housing and housing the controller, The first battery mounting section is located in the controller housing section. The second battery mounting section is located in the motor housing section. The core drill according to claim 1.

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