JP5218819B2 - Electric tool - Google Patents

Description

  The present invention relates to a power tool, and more particularly to a power tool including a two-pole commutator motor.

As a power tool such as a disk grinder, a structure having a two-pole commutator motor as a power source is conventionally known. In the disc grinder, the two-pole commutator motor 1020 includes a stator 1025 and a rotor 1021 as shown in FIG. The stator 1025 includes a substantially cylindrical stator core 1026. As shown in FIG. 9, a stator slot 1026a is formed on the inner peripheral surface of the stator core 1026, and a stator coil bundle 1027 is formed in the stator slot 1026a. -1, 1027-2 are accommodated, and stator coil bundles 1027-1 and 1027-2 are wound around the stator core 1026. Stator coil bundles 1027-1 and 1027-2 each have a coil end portion 1028 protruding in the axial direction from a magnetic pole end portion corresponding to the axial end portion of stator core 1026, and drives motor 1020. During operation of the electric tool, current flows through the stator coil bundles 1027-1 and 1027-2. Resin molds 1027-1A and 1027-1B are applied to the stator coil bundles 1027-1 and 1027-2. Such a two-pole commutator motor is described in, for example, Japanese Unexamined Patent Application Publication No. 2006-67639 (Patent Document 1) and Japanese Unexamined Patent Application Publication No. 2006-141105 (Patent Document 2).
JP 2006-67639 A JP 2006-141105 A

  The stator of the two-pole commutator motor is housed and fixed in a housing 1010 that constitutes an electric tool such as a disk grinder. In this case, the two-pole commutator motor is fixed to the housing 1010 as shown in FIG. As shown in FIG. 8, the screw 1032 is screwed into the screw hole 1031 a formed in the stator core 1026, and the screw 1032 is further screwed into the screw hole (not shown) formed in the housing 1010. .

  However, if the screw hole 1031a is formed in the stator core 1026, the magnetic path becomes narrow, the amount of magnetic flux decreases, the output of the two-pole commutator motor 1020 decreases, and the workability deteriorates. If a screw hole is formed in a portion of the stator core that is away from the magnetic path so as not to affect the magnetic path, the stator core becomes large and the mass of the two-pole commutator motor increases, thereby improving workability. Becomes worse. Also, in order to prevent the magnetic path from being affected, if an attempt is made to fix the stator core and the housing using separate members, the material cost increases due to an increase in the number of parts, and the assemblability is further reduced, resulting in manufacturing. Man-hours in the process increase.

  On the other hand, in order to facilitate the manufacture of the stator 2025 having the molded stator coil bundles 2027-1 and 2027-2, the stator core 2026 includes a plurality of divided core portions 2026-1 and 2026-2. Later, the split core portions 2026-1 and 2026-2 may be joined together by argon welding 2026B or the like to form one stator core 2026. In this case, the magnetic characteristics of the stator core 2026 deteriorate due to the welding 2026B, the output of the two-pole commutator motor decreases, and workability deteriorates. For this reason, it is possible to suppress the deterioration of the magnetic properties of the stator core as much as possible by performing laser beam welding which has recently been used instead of the commonly used argon welding 2026B.

  However, laser beam welding necessitates the introduction of new equipment costs and the need for safety management when using lasers. For this reason, it is also conceivable that the split core portions are joined to each other using another member without performing these weldings. However, in this case, the material cost increases due to an increase in the number of parts, and the number of assembly steps increases.

  Accordingly, an object of the present invention is to provide an electric tool that can prevent a magnetic path from becoming narrow and a magnetic flux amount from decreasing, and reduce the manufacturing cost.

In order to achieve the above object, the present invention provides a two-pole commutator motor having a housing and a stator having a stator core that is housed and fixed in the housing and has a substantially cylindrical shape, and the stator. A plurality of stator coil bundles made of bundles of magnet wires are fixed to the inner peripheral surface of the stator core, and a resin mold is provided for each stator coil bundle. In the electric tool to which the resin mold is applied, a resin extending portion for connecting the resin molds of the plurality of stator coil bundles, which is made of the same resin as the resin constituting the resin mold, between the plurality of stator coil bundles. is provided, the resin extending section have a fixed portion which is fixed relative to the housing, the power tool unit out resin extends is provided radially outward relative to the coil end support inner peripheral surface providing.

Between the plurality of stator coil bundles, there is provided a resin extending portion that is made of the same resin as the resin constituting the resin mold and connects the resin molds of the plurality of stator coil bundles. Therefore, the resin-molded stator coil bundle can be fixed to the housing by fixing the fixing portion of the resin extending portion to the housing. Since the stator coil bundle is fixed to the stator core, the stator core can be fixed to the housing. For this reason, it is not necessary to form a screw hole in the stator core for screwing a screw for fixing the stator core to the housing, and the magnetic path can be formed with a constant width in the stator core. For this reason, it can prevent that the magnetic characteristic of a stator core deteriorates and the output of a 2 pole commutator motor falls, and it can prevent that workability | operativity deteriorates. The fixing portion provided in the resin extending portion is fixed to the housing body at a position where the rotor of the motor and the resin extending portion do not interfere with each other. Thereby, it becomes possible to ensure a sufficient size of the rotor and prevent a decrease in motor output.

  Here, the stator core includes a plurality of split core portions, and a stator coil bundle including a bundle of magnet wires is fixed to a portion of the split core portion corresponding to the inner peripheral surface of the stator core, The plurality of divided core portions preferably form the stator core by directly contacting the core materials constituting the divided core portions.

  The stator core is composed of a plurality of split core portions, and a stator coil bundle consisting of a bundle of magnet wires is fixed to the portion of the split core portion corresponding to the inner peripheral surface of the stator core. The stator coil bundles can be connected by the resin extending portion that connects the two. Since the stator coil bundle is fixed to the split core portion, the core materials constituting the split core portion can be directly brought into contact with each other without using welding or an adhesive, so that the split cores can be coupled to each other. .

The present invention also includes a two-pole commutator motor having a rotor and a stator having a substantially cylindrical stator core, and a coil end support provided on the inner periphery of the stator core , The stator core includes a plurality of split core portions, and a stator coil bundle including a bundle of magnet wires is fixed to each of the split core portions corresponding to the inner peripheral surface of the stator core. In a power tool in which a resin mold is applied to the bundle, the resin molds of the plurality of stator coil bundles are made of the same resin as that constituting the resin mold between the plurality of stator coil bundles. Resin extending portions are provided, resin extending portions are provided radially outward with respect to the inner peripheral surface of the coil end support portion, and the plurality of divided core portions are formed of core materials constituting the divided core portions. The stator core It has to offer to the electric tool.

The stator core includes a plurality of split core portions, and a stator coil bundle including a bundle of magnet wires is fixed to each of the split core portions corresponding to the inner peripheral surface of the stator core. Since there is a resin extending portion that connects the resin molds of a plurality of stator coil bundles, the resin extending portion that connects the resin molds is provided between the resin molds. Each stator coil bundle can be connected. Since the stator coil bundle is fixed to the split core portion, the core materials constituting the split core portion can be directly brought into contact with each other without using welding or an adhesive, and the split core portions can be coupled to each other. it can. For this reason, it can prevent that the magnetic characteristic of a stator core deteriorates and the output of a 2 pole commutator motor falls in the contact part which mutually contacts a split core part, and workability | operativity worsens. This can be prevented. The fixing portion provided in the resin extending portion is fixed to the housing body at a position where the rotor of the motor and the resin extending portion do not interfere with each other. Thereby, it becomes possible to ensure a sufficient size of the rotor and prevent a decrease in motor output.

As mentioned above, this invention can provide the electric tool which can prevent that a magnetic path becomes narrow and a magnetic flux amount decreases, and can aim at reduction of manufacturing cost. The fixing portion provided in the resin extending portion is fixed to the housing body at a position where the rotor of the motor and the resin extending portion do not interfere with each other. Thereby, it becomes possible to ensure a sufficient size of the rotor and prevent a decrease in motor output.

  A power tool according to a first embodiment of the present invention will be described with reference to FIGS. More specifically, the electric power tool 1 is a disc grinder, and, as shown in FIG. 1, a housing that houses and fixes a two-pole commutator motor 20 having a rotor 21, a stator 25, and a commutator 35. 10, a grindstone 71 provided at the front end of the housing 10, a fan 12, a power switch 41, a switch handle, and a tail cover 40 fixed to the rear end of the housing 10.

  The interior of the housing 10 and the tail cover 40 communicate with each other, and the tail cover 40 is formed with an air inlet 40a that communicates the interior of the tail cover 40 and the interior of the housing 10 with the atmosphere. A gear cover 60 is fixedly provided at the front end of the housing 10, and the gear cover 60 has a fan air discharge port 60 a (FIG. 2) for communicating the atmosphere and the inside of the housing 10 to discharge a fan air to be described later. Is formed. As shown in FIG. 1, the output shaft 20A of the two-pole commutator motor 20 is configured to be coaxially and integrally rotatable with the rotation shaft of the rotor 21, extends into the gear cover 60, and near the tip thereof. Is provided with a gear 61 coaxially rotatable with the output shaft 20A.

  The gear 61 is engaged with a gear 62 that is fixed to a rotary shaft 63 that is rotatably supported in the gear cover 60 and that can rotate coaxially and integrally with the rotary shaft 63. The rotary shaft 63 shown in FIG. A grindstone 71 having a substantially disk shape is attached coaxially to the rotary shaft 63 so as to be rotatable integrally therewith. With this configuration, the grindstone 71 is configured to rotate when the rotor 21 of the two-pole commutator motor 20 rotates.

  The fan 12 is fixed to a part of the output shaft 20A of the two-pole commutator motor 20 and in the vicinity of the gear cover 60 in the housing 10, and the rotor 21 rotates to rotate the two-pole commutator motor 20. The output shaft 20A is coaxially and integrally rotatable. The fan 12 is composed of a centrifugal fan having a plurality of blades 12A.

  The two-pole commutator motor 20 includes a stator 25 and a rotor 21. As shown in FIG. 3, the stator 25 includes a substantially cylindrical stator core 26, and a pair of stator slots (not shown) are formed on the inner peripheral surface thereof. Part of the stator coil bundles 27-1 and 27-2 are accommodated in a pair of stator slots (not shown), and the two stator coil bundles 27-1 and 27-2 are wound around the stator core 26. Has been. The two stator coil bundles 27-1 and 27-2 have coil end portions 28 and 29 (FIG. 1) that protrude in the axial direction from the magnetic pole end corresponding to the axial end of the stator core 26. doing.

  In addition, a pair of projecting portions (not shown) projecting inward in the radial direction of the stator core 26 from the inner circumferential surface of the stator core 26 extends in the axial direction of the stator core 26. The coil end support portion 26A is provided. The coil end support portion 26 </ b> A is arranged coaxially with the inner peripheral surface of the stator core 26 and has a shape that forms a part of a substantially cylinder having a smaller radius than the inner peripheral surface of the stator core 26. The coil end portions 28 and 29 are supported by the outer peripheral surface of the coil end support portion 26 </ b> A, and the coil end portions are fixed to the stator core 26.

  Resin molds 27-1A and 27-1B are respectively applied to the two stator coil bundles 27-1 and 27-2, and the resin molds 27-1A of the two stator coil bundles 27-1 and 27-2 are provided. 27-1B are connected by a resin extending portion 31 in the circumferential direction of the stator core 26 shown in FIG. The resin extending portion 31 is made of the same resin as that constituting the resin molds 27-1A and 27-1B and is formed integrally with the resin molds 27-1A and 27-1B.

  A screw hole 31a is formed in a portion of the resin extending portion 31 corresponding to a substantially central position between the two stator coil bundles 27-1 and 27-2. The portion of the resin extending portion 31 in which the screw hole 31a is formed corresponds to a fixed portion. As shown in FIG. 4, a screw 32 is screwed into the screw hole 31a. The tip of the screw 32 is screwed into a screw hole 10a (FIG. 2) formed in the housing 10 and screwed with a female screw. doing. Accordingly, the fixing portion of the resin extending portion 31 is fixed to the housing 10 by the screw 32. Since the resin extending portion 31 is integral with the resin molds 27-1A and 27-1B of the stator coil bundles 27-1 and 27-2, the stator coil bundles 27-1 and 27-2 are resin molds 27-1A. 27-1B and the resin extending portion 31 are fixed to the housing 10. Further, since the stator coil bundles 27-1 and 27-2 are fixed to the stator core 26, the stator core 26 includes the stator coil bundles 27-1 and 27-2 and the resin molds 27-1A and 27. It is fixed to the housing 10 via -1B and the resin extending portion 31.

  In this way, between the two stator coil bundles 27-1 and 27-2, the two stator coil bundles 27-1 made of the same resin as that constituting the resin molds 27-1A and 27-1B are provided. 27-2 is provided with a resin extending portion 31 that connects the resin molds 27-1A and 27-1B, and the resin extending portion 31 has a fixing portion that is fixed to the housing 10. Therefore, the stator core 26 Can be fixed to the housing 10. For this reason, it is not necessary to form a screw hole in the stator core 26 for screwing the screw 32 for fixing the stator core 26 to the housing 10, and a magnetic path is formed with a constant width in the stator core 26. can do. For this reason, it can prevent that the magnetic characteristic of the stator core 26 deteriorates and the output of the 2 pole commutator motor 20 falls, and it can prevent that workability | operativity deteriorates.

  Next, a power tool according to a second embodiment of the present invention will be described with reference to FIGS. The electric power tool according to the second embodiment is different from the first embodiment in that the stator core 126 is composed of two divided core portions 26-1 and 26-2. The configuration is the same as that of the first embodiment. Therefore, only the points different from the first embodiment will be described, and the same members as those of the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 5 to FIG. 6, the stator core 126 is configured to be divided into a pair of split core portions 26-1 and 26-2. The split surfaces 26-1A and 26-2A of the stator core 126 are arranged in the middle of the magnetic path connecting the two magnetic poles of the stator 25. One of the stator core dividing surfaces 26-1A and 26-2A has a valley shape, and the other has a mountain shape. The stator core dividing surfaces 26-1A and 26-2A having a valley shape and a mountain shape are 2 They are in a positional relationship parallel to the rotation axis of the rotor 21 (FIG. 1) that coincides with the output shaft of the polar commutator motor 20. No adhesive or the like is interposed between the split surfaces 26-1A and 26-2A of the stator core 126, and welding is not performed. The core materials constituting the split core portions 26-1 and 26-2 are in direct contact with each other. The stator coil bundles 27-1 and 27-2 are respectively fixed to the split core portions 26-1 and 26-2 by a coil end support portion 26A.

  The stator core 126 is composed of two divided core portions 26-1 and 26-2, and the divided core portions 26-1 and 26-2 corresponding to the inner peripheral surface of the stator core 126 are formed of a bundle of magnet wires. The stator coil bundles 27-1 and 27-2 are fixed, and the same resin as the resin constituting the resin molds 27-1A and 27-1B is provided between the two stator coil bundles 27-1 and 27-2. Since the resin extending portions 31 for connecting the resin molds 27-1A and 27-1B of the two stator coil bundles 27-1 and 27-2 are provided, the resin molds 27-1A and 27-1B are provided. The stator coil bundles 27-1 and 27-2 can be connected by the resin extending portion 31 that connects the two. Since the stator coil bundles 27-1, 27-2 are fixed to the split core portions 26-1, 26-2, the split core portions 26-1, 26-2, The split core portions 26-1 and 26-2 can be coupled to each other by directly abutting the core materials constituting the 26-2. For this reason, it prevents that the magnetic characteristic of the stator core 26 deteriorates and the output of the 2 pole commutator motor 20 falls in the contact part which mutually contacts the split core parts 26-1 and 26-2. It is possible to prevent the workability from being deteriorated.

  Next, an electric tool according to a third embodiment of the present invention will be described with reference to FIG. In the electric power tool according to the third embodiment, concave portions 31b and 31b are formed in the fixing portion of the resin extending portion 31, and the convex portions 26-1C and 26- engaged with the concave portion 31b and 31b are formed in the stator core 226. The second embodiment is different from the second embodiment in that 2C is provided, and the other configuration is the same as that of the second embodiment. Therefore, only the points different from the second embodiment will be described, and the same members as those of the second embodiment are denoted by the same reference numerals.

  As shown in FIG. 7, a portion of the fixing portion of the resin extending portion 231 in the circumferential direction of the stator core 226 and near the screw hole 31a is cut perpendicularly to the axial direction of the stator core 226. A pair of recesses 31b, 31b having a substantially triangular cross section are formed. Convex portions 26-1C and 26-2C corresponding to the shapes of the concave portions 31b and 31b are respectively provided in the divided core portions 26-1 and 26-2 facing the pair of concave portions 31b and 31b. As shown in FIG. 7, when the stator coil bundles 27-1 and 27-2 provided with the resin extending portion 231 and the resin molds 27-1 A and 27-1 B are assembled in the stator core 226, the division is performed. The convex portions 26-1C and 26-2C of the core portions 26-1 and 26-2 are engaged with the concave portions 31b and 31b of the two resin extending portions 31, and the divided core portions 26-1 and 26-2 are resin extending. It is comprised so that it can fix to the part 231 more reliably.

  In addition, the electric tool by this invention is not limited to embodiment mentioned above, A various deformation | transformation and improvement are possible in the range described in the claim.

The side view fragmentary sectional view which shows the electric tool by the 1st Embodiment of this invention. FIG. 3 is a partial cross-sectional view in plan view showing the electric tool according to the first embodiment of the present invention. The front view which shows the stator core and stator coil bundle | flux of the electric tool by the 1st Embodiment of this invention. The front view which shows the stator core of the electric tool by the 1st Embodiment of this invention, a stator coil bundle | flux, a housing, and a rotor. The front view which shows the stator core and stator coil bundle | flux of an electric tool by the 2nd Embodiment of this invention. Sectional drawing which shows the stator core and stator coil bundle | flux of the electric tool by the 2nd Embodiment of this invention. The front view which shows the stator core and stator coil bundle | flux of an electric tool by the 3rd Embodiment of this invention. The front view which shows the stator core of the conventional electric tool, a stator coil bundle, a housing, and a rotor. The front view which shows the stator core of the conventional electric tool. The perspective view which shows the stator core and stator coil bundle of the conventional electric tool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electric tool 10 ... Housing 20 ... Two-pole commutator motor 21 ... Rotor 25 ... Stator 26, 126, 226 ... Stator core 26-1, 26-2 ... Split core parts 27-1, 27-2 ... Stator coil bundles 27-1A, 27-1B ... Resin molds 31, 231, ... Resin extension parts

Claims (3)

A housing;
A two-pole commutator motor housed and fixed in the housing and having a rotor and a stator having a substantially cylindrical stator core; and a coil end support provided on the inner periphery of the stator core. ,
In the electric tool in which a plurality of stator coil bundles composed of bundles of magnet wires are fixed to the inner peripheral surface of the stator core, and each stator coil bundle is resin-molded,
Between the plurality of stator coil bundles, a resin extending portion for connecting the resin molds of the plurality of stator coil bundles made of the same resin as the resin constituting the resin mold is provided,
Power tool said resin extending portion, characterized in that have a fixed portion which is fixed, portion out resin extending radially outward relative to the coil end support inner peripheral surface is provided for the housing . The stator core includes a plurality of split core portions, and a stator coil bundle including a bundle of magnet wires is fixed to a portion of the split core portion corresponding to the inner peripheral surface of the stator core,
The power tool according to claim 1, wherein the plurality of divided core portions form the stator core by directly abutting core materials constituting the divided core portions. A two-pole commutator motor having a rotor and a stator having a substantially cylindrical stator core, and a coil end support provided on the inner periphery of the stator core ;
The stator core includes a plurality of split core portions, and a stator coil bundle including a bundle of magnet wires is fixed to each of the split core portions corresponding to the inner peripheral surface of the stator core. In a power tool with a resin mold on the bundle,
Resin extending portion for connecting the resin molded between the stator coil bundle the plurality of made of the same resin and the resin constituting the resin mold is provided between the stator coil bundle the plurality of, the coil end support A resin extending portion is provided on the radially outer side with respect to the inner peripheral surface,
The power tool characterized in that the plurality of divided core portions form the stator core by directly abutting core materials constituting the divided core portions.

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