JP5311276B2 - Electric tool - Google Patents

Description

  The present invention relates to a power tool, and more particularly to a motor that drives the power tool.

  Electric tools are often used with a high load, and a large current flows through a motor coil due to an overload operation, and the coil may burn out. In order to suppress this heat generation, there is a method in which the resistance value of the coil is lowered by increasing the diameter of the conducting wire used in the coil. However, since the winding space of the coil is limited by the motor, the diameter of the wire that can be wound is limited.

  Therefore, for example, in the stator, the coil space is improved by dividing the core that constitutes the stator, and the winding process is facilitated. A method for suppressing heat generation by winding a wire to form a coil has been applied.

As described above, when the core constituting the stator is divided into a plurality of divided cores, it is necessary to integrate the divided cores after winding the coils around the divided cores. With regard to this integration, a method for integrating the respective joints of a plurality of cores by welding, and as shown in Patent Document 1, the joints of the cores are fitted in a bowl shape to be integrated. There is a way to do it.
Japanese Patent No. 3264329

  When joining a joint part by welding, there was a possibility that the core may be altered by welding and the magnetic performance may be deteriorated. Moreover, when fitting a junction part, the shape of the division | segmentation core became complicated and productivity was inferior. Further, when fitting the hook-shaped portion, a high pressure input is required, and the integration process is not easy.

  Therefore, an object of this invention is to provide the electric tool provided with the motor which suppresses the performance reduction of the core which comprises a stator and can be integrated easily.

In order to solve the above problems, the present invention includes a housing and a motor that is disposed in the housing and drives a tip tool, and the motor includes a stator that is held in the housing, and a stator. a plurality of coil portions to be mounted, the cross-sectional surface that is rotatably disposed within the stator perpendicular to the rotary shaft is constituted by a substantially circular rotor, stator extending parallel to said rotation axis It is composed of a frame that is formed by combining a plurality of divided cores associated with each other on a dividing surface, and the frame is provided with a plurality of restraining tools that connect the plurality of divided cores. some of the outer peripheral surface when the frame body structure with the engaged portions are formed respectively, said restraint toward the inner an installation position of the restraint in a state in which said restraint is attached to the frame body Receiving grooves are respectively formed, and the plurality of restraining tools are The first locking portion locked to the locked portion of the first split core and the locked portion of the second split core adjacent to the first split core are locked. A second locking part, and a connecting part that connects the first locking part and the second locking part , the receiving groove part extending in the circumferential direction of the frame body, A plurality of steel plates are laminated in the axial direction of the rotating shaft, and the plurality of steel plates are part of the outer peripheral surface with a part of the peripheral edge forming the bottom surface of the receiving groove portion A bottom surface forming plate that provides a stop, and a peripheral surface forming plate in which a part of the periphery forms the other part of the outer peripheral surface, and the restraining tool has a substantially arc shape along the outer peripheral shape of the frame body The first locking portion and the second locking portion are formed in a substantially U shape having a substantially arc shape along the outer peripheral shape of the frame body. At one end and the other end in the circumferential direction Each of the locked portions is provided by a locking groove portion that extends in the axial direction and is formed at a substantially center of the peripheral surface in the circumferential direction of the frame body, and the restraining tool is provided in the circumferential direction. The first locking portion and the second locking portion are configured by bending both end portions in the lengthwise direction of the plate-like member in a hook shape, Of the plurality of restraining tools, the first locking portion of the first restraining device is hooked and locked to the other inner surface of the locking groove in the first split core, The second locking portion of the second restraining tool adjacent to the restraining tool provides an electric tool that is hooked and locked to one inner surface of the locking groove in the first split core. .

  According to such a configuration, since the split core is connected by the restraining tool, the split core can be integrated without using means such as welding. In addition, the split core needs to be formed with locked portions that are locked by the first and second locking portions of the restraining tool. It is only necessary to adopt a configuration that can regulate the movement of the second divided core in the direction from the first divided core toward the adjacent second divided core, and it is not necessary to adopt a complicated shape. Moreover, since a restraint tool is arrange | positioned in the accommodation groove part of a division | segmentation core, and is located in a circumferential surface inner side, it is suppressed that a restraint tool protrudes from the outer peripheral part of a frame body in the state which formed the frame body.

According to such configuration of this, it is possible to easily form the receiving groove.

  According to such a configuration, the restraining tool locked in the locking groove is difficult to come off from the locking groove. Therefore, it is suppressed that a restraint tool remove | deviates from a frame after mounting a restraint tool to a frame.

  According to the electric tool of the present invention, it is possible to suppress the performance reduction of the cores constituting the stator and to easily integrate these cores.

  Hereinafter, a power tool according to an embodiment of the present invention will be described with reference to FIGS. 1 to 9. A disc grinder 1 that is an electric tool shown in FIG. 1 mainly includes a housing 2, a motor 3, a gear mechanism 6, and a grindstone 7 that is a tip tool.

  The housing 2 accommodates the motor 3 therein, and has a tail cover 21 that accommodates a power switch (not shown) that supplies power to the motor 3 at the rear end. A gear cover 22 incorporating the gear mechanism 6 is provided at the tip. The tail cover 21 is formed with an air suction hole 21a for taking in the outside air into the housing 2, and the gear cover 22 is formed with an air discharge hole 22a for discharging the air inside the housing 2 into the outside air. The motor 3 is mainly composed of a stator 3A and a rotor 3B, and an output shaft 31 is provided at a tip portion of the rotor 3B. A fan 32 is provided at the root portion of the output shaft 31, and the fan 32 rotates as the output shaft 31 rotates to generate an air flow from the air suction hole 21 a to the air discharge hole 22 a in the housing 2. The motor 3 is cooled.

  The gear mechanism 6 mainly includes a first bevel gear 61, a second bevel gear 62, and a rotating shaft 63, and is accommodated in the gear cover 22. The first bevel gear 61 is provided on the output shaft 31, and the second bevel gear 62 is disposed so that the rotation shaft is orthogonal to the output shaft 31 and meshes with the first bevel gear 61. The rotating shaft 63 is fixed to the second bevel gear 62 so as to be coaxially rotatable, is supported by the gear cover 22 via a bearing, and functions as a rotating shaft of the second bevel gear 62.

  The grindstone 7 is fixed to the tip of the rotary shaft 63 and is configured to be rotatable coaxially with the rotary shaft 63. A cover 7 </ b> A that is fixed to the gear cover 22 and protects the grindstone 7 is provided around the grindstone 7. Since the grindstone 7 is fixed to the rotary shaft 63 so as to be coaxially rotatable, the grindstone 7 is rotated by the rotation of the output shaft 31 of the motor 3 so that the workpiece can be cut and polished.

  Next, the motor 3 will be described. The motor 3 is a two-pole commutator motor having two magnetic poles, and takes a form in which the rotor 3B is accommodated in the internal space of the stator 3A. The stator 3A is mainly composed of symmetrical first and second stator cores 4 and 4 which are divided into halves using a metal material as a base material. The first and second stator coil bundles 3C and 3C attached to the child core 4 are wound around a magnetic pole portion 41 described later, and the symmetrical first and second stator cores 4 and 4 have a plurality of restraints. It is restrained and connected by the tool 8 and is held in the housing 2 by first and second yoke portions 42A and 42B, which will be described later, serving as outer peripheral portions. As shown in FIG. 2, the first and second stator cores 4, 4 are combined to form a frame that constitutes the stator 3 </ b> A, and a through hole that penetrates in a direction perpendicular to the outer peripheral direction of the frame Form.

  The rotor 3B is configured in a columnar shape, and an output shaft 31 serving as a rotation shaft is disposed in a shaft portion of the column. Yes. The direction of the through hole in the first and second stator cores 4 and 4 is hereinafter defined as the axial direction, and is orthogonal to the axial direction along the outer periphery of the frame configured by the first and second stator cores 4 and 4. This direction is defined as the outer circumferential direction. Moreover, the part used as the outer periphery of the frame comprised from the 1st, 2nd stator cores 4 and 4 is defined as the outer periphery of each of the 1st and 2nd stator cores 4 and 4. FIG.

Since the second stator cores 4 and 4 are all symmetrical, the first stator core 4 will be described unless otherwise specified. The first stator core 4 is configured by laminating a first steel plate 4A and a second steel plate 4B each having a thickness of about 0.5 mm in the axial direction. The second steel plate 4B is laminated as a bottom surface forming plate at four axial ends of the first stator core 4, and the first steel plate 4A is formed between the second steel plates 4B stacked at both ends. A plurality of sheets are stacked as a plate . As shown in FIGS. 4 and 5 (a) and 5 (b), the first steel plate 4A and the second steel plate 4B are respectively positioned on one end side and the other end side in the circumferential direction of the magnetic pole portion 41 and the magnetic pole portion 41, respectively. The first yoke portion 42A and the second yoke portion 42B are configured so that the configurations of the outer peripheral portions of the first yoke portion 42A and the second yoke portion 42B are different.

  As shown in FIG. 4, each magnetic pole portion 41 of the first steel plate 4 </ b> A and the second steel plate 4 </ b> B includes a magnetic pole 41 </ b> C adjacent to the rotor 3 </ b> B (FIG. 1), one end side in the circumferential direction from the magnetic pole 41 </ b> C, and the like. The first arm portion 41 </ b> A and the second arm portion 41 </ b> B extend toward the end side in a state of being close to the rotor 3 </ b> B (FIG. 1). Further, a conductive wire is wound between the first arm portion 41A and the first yoke portion 42A, and between the second arm portion 41B and the second yoke portion 42B, thereby forming the first stator coil bundle 3C. A first slot 41a and a second slot 41b are formed. The first stator core 4 to the second stator core are connected to the first stator core 4 and the second stator core 4 at a position on the outer peripheral surface of the magnetic pole portion 41 and the back surface of the magnetic pole 41C. A plane perpendicular to the virtual axis toward 4 is formed, a first locking surface 4C is defined on one side of the outer circumferential direction of this plane, and a second locking surface 4D is defined on the other side in the outer circumferential direction. The locked portion is configured by the first locking surface 4C and the second locking surface 4D. One locking groove extending in the axial direction is provided between the first locking surface 4C and the second locking surface 4D and at a position substantially at the center in the circumferential direction on the outer periphery of the first stator core 4. 4a is formed.

  At the front end of the first yoke portion 42A in the extending direction from the magnetic pole portion 41, a convex portion 43A that constitutes a split surface to be brought into contact with the second yoke portion 42B of the second stator core 4 is provided. A concave portion 43b defined by a split surface mated with the first yoke portion 42A of the second stator core 4 is formed at the front end of the portion 42B in the extending direction from the magnetic pole portion 41. Therefore, the convex portion 43A and the concave portion 43b of the first stator core 4 are fitted into the concave portion 43b and the convex portion 43A of the second stator core 4, respectively, so that the first stator core 4 and the second stator core 4 are fitted. And are securely joined.

Moreover, the curvature radius D1 of the peripheral surface 4E in the first yoke portion 42A and the second yoke portion 42B of the first steel plate 4A shown in FIG. 5A is the same as that of the second steel plate 4B shown in FIG. 5B . The one yoke portion 42A and the second yoke portion 42B are configured to be larger than the radius of curvature D2 of the peripheral surface 4F (FIG. 3). Therefore, as shown in FIGS. 3 and 4, when a plurality of the first steel plates 4A and the second steel plates 4B are stacked, the peripheral surface 4F is formed on the first steel plate 4A and the peripheral surface 4F of the second steel plate 4B. A groove 4b, which is a housing groove portion having a bottom surface as a bottom, is formed. The depth ΔD (= (D1−D2) / 2) of the groove 4b is configured to be substantially the same as or slightly larger than the plate thickness of a metal plate to be described later constituting the restraint 8.

  In each of the first steel plate 4A and the second steel plate 4B, the magnetic pole portion 41, the first yoke portion 42A, and the second yoke portion are arranged in the same position in a state where the first steel plate 4A and the second steel plate 4B are laminated. Caulking pieces 44A to 44C are respectively formed at three locations with 42B. Therefore, as shown in FIG. 6, when the first steel plate 4A and the second steel plate 4B are laminated, the caulking piece 44A of the first steel plate 4A or the second steel plate 4B adjacent to the space where the caulking piece 44A is punched is fitted. To do. Since the crimping pieces 44B and 44C are similarly fitted, the plurality of first steel plates 4A and the second steel plates 4B can be maintained in a stacked state. In addition, as shown in FIG. 6, with respect to the two second steel plates 4B serving as the end portions in the direction in which the crimping piece 44A protrudes, holes 44a having the same contour as the crimping piece 44 are formed instead of the crimping piece 44A, respectively. Has been. This also adopts the same configuration in the caulking pieces 44B and 44C. Accordingly, when the first stator core 4 is configured by laminating the plurality of first steel plates 4A and the second steel plates 4B, the caulking pieces 44 protrude from the end portions in the axial direction of the first stator core 4. It is suppressed.

The restraining tool 8 is manufactured by bending a long metal plate having spring characteristics, and as shown in FIG. 7 , the first locking portion 8A and the second engaging portion are located at one end and the other end in the longitudinal direction, respectively. It is comprised from the stop part 8B and the connection part 8C located between the 1st latching | locking part 8A and the 2nd latching | locking part 8B. 8 A of 1st latching | locking parts and the 2nd latching | locking part 8B are comprised by the substantially parallel flat form, respectively, and the connection part 8C is comprised by the circular arc shape along the outer periphery shape of a frame. Therefore, the restraint tool 8 is shaped into a substantially U shape with the first locking portion 8A and the second locking portion 8B as arms. The distance from the first locking portion 8A to the second locking portion 8B is such that the first stator core 4 and the second stator core 4 are joined together in the state where the first stator core 4 and the second stator core 4 are joined. The distance from the plane including the stop surface 4C and the second locking surface 4D to the plane including the first locking surface 4C and the second locking surface 4D of the second stator core 4 is slightly shorter.

  After forming the first stator core 4 by laminating the plurality of first steel plates 4A and the second steel plates 4B, the surface is subjected to insulation coating or the like, as shown in FIGS. 8 (a) and 8 (b), A conducting wire is wound around the magnetic pole portion 41 so as to be wired in the first slot 41a and the second slot 41b, and the first stator coil bundle 3C is formed and attached. Similarly, the second stator coil bundle 3C is mounted on the second stator core 4, and thereafter, the convex portions 43A and concave portions 43b of the first stator core 4 and the concave portions 43b and convex portions of the second stator core 4 are provided. The first stator core 4 and the second stator core 4 are joined by fitting with 43A.

  After the first stator core 4 and the second stator core 4 are joined by the portion 43 </ b> A and the recessed portion 43 b, the restraining tool 8 is mounted across the first stator core 4 and the second stator core 4. When the restraint 8 is mounted on the other end of the housing groove 4 a of the first stator core 4, the first locking portion 8 </ b> A is engaged with the second locking of the first stator core 4 as shown in FIG. 2. The second locking portion 8B is in contact with the surface 4D, the second locking portion 8B is in contact with the first locking surface 4C of the second stator core 4, and the connecting portion 8C is mounted so as to be accommodated in the groove 4b (FIG. 8). When the restraint 8 is mounted on one end side of the housing groove 4a of the first stator core 4, the first locking portion 8A comes into contact with the second locking surface 4D of the second stator core 4, and the second The engaging portion 8B is attached so as to abut on the first engaging surface 4C of the first stator core 4 and the connecting portion 8C is accommodated in the groove 4b (FIG. 8). The first locking surface 4C and the second locking surface 4D are planes orthogonal to the direction from the first stator core 4 toward the second stator core 4, respectively. The first locking portion 8A and the second locking portion 8B that are in contact with the surface 4D have a distance between the first locking surface 4C and the second locking surface 4D of the first stator core 4 and the second stator core. 4 is smaller than the distance to the first locking surface 4C and the second locking surface 4D, and the first stator core 4 and the second stator core 4 are clamped and restrained by the restraining tool 8, and the first fixing is performed. The child core 4 and the second stator core 4 are integrated without being separated from each other.

  Since the restraining tool 8 is housed and mounted in the groove 4b and is located inward from the peripheral surface 4E of the first steel plate 4A serving as the outer periphery of the stator 3A, the increase in size of the stator 3A is suppressed. Is done. Further, since the restraint 8 is made of metal, after being attached to the first stator core 4 and the second stator core 4, it becomes a part of the magnetic path through which the magnetic flux passes. Therefore, it is possible to suppress a decrease in magnetic performance between the first stator core 4 and the second stator core 4 due to the formation of the grooves 4b.

  Further, the first locking surface 4C and the second locking surface 4D need only be locked with the restraining tool 8 in the direction from the first stator core 4 toward the second stator core 4, and therefore, in the present embodiment. As shown, there is no inconvenience even if it is configured in a planar shape. Conversely, the first locking surface 4C and the second locking surface 4D can be easily configured by configuring in a planar shape. Further, when the first locking portion 8A and the second locking portion 8B are mounted on the first locking surface 4C and the second locking surface 4D, the first locking portion 8A and the second locking portion 8B are the first. Since the mounting is performed by sliding on the flat surfaces of the locking surface 4C and the second locking surface 4D, the mounting becomes easy.

  In the electric tool of this invention, it is not limited to the above-mentioned embodiment, A various deformation | transformation and improvement are possible in the range described in the claim. For example, as shown in FIG. 10, in the restraining tool 108, the respective leading ends of the first locking portion 108A and the second locking portion 108B may be bent in a hook shape. Then, as shown in FIG. 11, the hook-shaped portion provided in the first locking portion 108A is hooked to the other end side surface 41D that defines the locking groove 4a, and is provided in the second locking portion 108B. By hooking the hook-like portion on one end side surface 41D that defines the locking groove 4a, it is possible to prevent the attached restraining tool 108 from falling off from the first stator core 4 and the second stator core 4. .

  Further, in the present embodiment, the grooves for accommodating the restraining tool are formed at two positions on both ends in the axial direction in the first stator core 4. However, the present invention is not limited to this, and a groove is formed in the substantially intermediate portion in the axial direction as shown in FIG. 4b may be provided. By adopting this configuration, after the first stator core 4 and the second stator core 4 are constrained by a restraining tool, the axial displacement between the first stator core 4 and the second stator core 4 is suppressed. can do.

  In the present embodiment, a bipartite core is used. However, the present invention is not limited to this, and a multi-divided core such as a tripartite core can also be applied. Moreover, although the restraint tool was comprised in the substantially U shape, not only this but circular arc shape may be sufficient.

Side surface sectional drawing of the electric tool concerning embodiment of this invention. The front view of the stator of the electric power tool concerning an embodiment of the invention. The top view of the stator core of the electric tool concerning embodiment of this invention. The front view of the stator core of the electric tool concerning embodiment of this invention. The front view of (a) 1st steel plate (b) 2nd steel plate which comprises the stator core of the electric tool concerning embodiment of this invention. The fragmentary sectional view which shows the joining location by crimping of the stator core of the electric tool concerning embodiment of this invention. The perspective view of the restraint tool of the electric tool concerning embodiment of this invention. The (a) top view (b) front view of the state which mounted | wore the stator of the electric tool concerning embodiment of this invention with the stator coil bundle mounted. The top view of the stator of the electric tool concerning embodiment of this invention. The perspective view of the restraint tool of the electric tool concerning the modification of embodiment of this invention. The front view in the state where the restraint tool was equipped to the stator of the electric tool concerning the modification of an embodiment of the invention. The top view in the state which mounted | wore the stator coil bundle with the stator of the electric tool concerning the modification of embodiment of this invention.

Explanation of symbols

1. Disc grinder 2. Housing 3. Motor 3A. Stator 3B. Rotor 3C ... First, second stator coil bundle 4. First, second stator core 4A ... First Steel plate 4B ... Second steel plate 4C ... First locking surface 4D ... Second locking surface 4E ... Peripheral surface 4a ... Locking groove 4b ... Groove 6 ... Gear mechanism 7 ... Grinding wheel 7A ... Cover 8 ·· Restraining tool 8A ·· First locking portion 8B ·· Second locking portion 8C ·· Connecting portion 21 ·· Tail cover 21a ·· Air intake hole 22 ·· Gear cover 22a ·· Air discharge hole 31 · · Output shaft 32 · · Fan 41 · · Magnetic pole portion 41A · · First arm portion 41B · · Second arm portion 41C · · Magnetic pole 41a · · First slot 41b · · Second slot 42A · · First yoke portion 42B・ ・ Second yoke part 43A ・ ・ Convex part 43b ・ ・ Concave parts 44A to 44C ・ ・ Oak 44a · · · hole 61 · · first bevel gear 62 · · second bevel gear 63 · · rotating shaft

Claims (1)

A housing;
A motor disposed in the housing and driving a tip tool,
The motor comprises a stator that is held by the housing, a plurality of coil portions mounted on the stator, the cross-sectional surface that is rotatably disposed within the stator perpendicular to the rotation axis of the substantially circular rotor And configured with
The stator is composed of a frame configured by combining a plurality of split cores joined together by a split surface extending in parallel with the rotation axis,
The frame body is provided with a plurality of restraining tools for joining a plurality of divided cores,
The plurality of split cores have a locked portion formed on a part of the outer peripheral surface at the time of the frame structure, and the mounting position of the restraining tool and the restraining tool being mounted on the frame body accommodating groove accommodating the restraint is formed respectively on the inner side in,
The plurality of restraining tools include a first locking portion locked to the locked portion of the first split core and the locked portion of the second split core adjacent to the first split core. A second locking portion locked to the locking portion, and a connecting portion that connects the first locking portion and the second locking portion, respectively .
The housing groove extends in the circumferential direction of the frame,
The split core is configured by laminating a plurality of steel plates in the axial direction of the rotating shaft,
The plurality of steel plates include a bottom surface forming plate that provides a portion of the outer peripheral surface with a part of the peripheral edge forming the bottom surface of the housing groove and a part of the peripheral edge of the outer peripheral surface. A peripheral surface forming plate constituting the other part,
The restraining tool is formed in a substantially arc shape along the outer peripheral shape of the frame body, or formed in a substantially U shape with a substantially arc shape along the outer peripheral shape of the frame body,
The first locking part and the second locking part are respectively provided at one end and the other end of the frame body in the circumferential direction,
The locked portion is provided by a locking groove portion that extends in the axial direction and is formed at a substantially center of the peripheral surface in the circumferential direction of the frame,
The restraint device is composed of a plate-like member having a long length in the circumferential direction, and the first locking portion and the second locking portion are formed so that both end portions in the lengthwise direction of the plate-like member are bowl-shaped. Composed of folded,
Of the plurality of restraining tools, the first locking portion of the first restraining device is hooked and locked to the other inner surface of the locking groove in the first split core, The second locking portion of the second restraining tool adjacent to the restraining tool is hooked and locked to one inner surface of the locking groove in the first divided core. Electric tool to do.

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