TWI677412B - Power tools - Google Patents

Abstract

An object of the present invention is to provide a power tool that can more easily and safely operate the inside of a housing.解决 The solution of the present invention is a power tool (10) provided with a commutating motor (14) in a casing (12). The casing (12) includes a first casing portion (30), a second casing portion (32) provided to be movable with respect to the first casing portion (30), and tapping screws (34) for fixing these, and It becomes a cover (36) that can be sandwiched between the first case portion (30) and the second case portion (32). When the tapping screw (34) is loosened, the tapping screw (34) is shifted away from the first housing portion (30) and engages with the engagement ring (50) of the second housing portion (32), so that The second housing portion (32) is displaced in this direction. Thereby, the cover (36) is made detachable. In addition, when the tapping screw (34) is tightened, the second housing portion (32) is displaced toward the first housing portion (30) by the tapping screw (34), so that the cover (36) is restored to be Clamped state.

Description

Power tools

The present invention relates to a power tool having a power section in a housing.

In a power tool having a power section in a casing, an operator can generally disassemble the casing to perform maintenance on the power section and the like arranged in the casing. For example, Patent Document 1 discloses a grinding machine including a commutating motor as a power unit in a housing composed of a motor housing and a rear cover. Generally speaking, a commutating motor is formed by contacting a carbon brush with a rectifier rotating with the rotor to supply current to the rotor. However, due to the friction between the carbon brush and the rotating rectifier, the carbon brush is gradually worn out, so it needs to be replaced periodically. In this grinder, the carbon brush is replaced after the fixing screw that fixes the rear cover to the motor casing is removed and the rear cover is removed. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2007-152479

[ Problems to be solved by the invention ]

Like the previous grinders, in the power tool that needs to remove a part of the housing for the maintenance of the power part arranged in the housing, there is a concern that the removed screws are missing, and the screws once removed are When it is installed again, it is necessary to perform fine work and become troublesome. In addition, when a part of the case is removed, there is a concern that the parts such as the electronic circuit or wiring arranged inside the case are exposed to the outside, which may cause damage to these parts.

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a power tool having a power section inside a housing and a power tool that can more easily and safely operate the inside of the housing. [ Means to solve the problem ]

That is, the present invention provides a power tool which is a power tool having a power section in a housing, and the housing includes a first housing section and a second housing section provided to be displaceable with respect to the first housing section. And fixing means for fixing the second housing part to the first housing part, and openings for internal operation for operating the inside of the housing, and being held between the fixing parts by the fixing means A cover is provided between the first housing portion and the second housing portion to close the opening for internal operation; The fixing means is provided to move away from the first housing portion when rotating in the first direction. The direction of displacement is to move toward the first housing portion when rotating in the second direction opposite to the first direction; The fixing means is set to: rotate in the first direction and move toward the first direction; When the direction away from the first case portion is shifted, the second case portion is engaged with the second direction in the distance direction to displace the second case portion in the distance direction and the clamp is released, so that the cover is enabled. From that 1 between the outer shell portion and the second outer shell portion; the fixing means is arranged to be stuck in the approaching direction after rotating in the second direction and displacing in a direction close to the first outer shell portion; Closing the second casing portion in the approaching direction causes the cover to be clamped between the first casing portion and the second casing portion.

In this power tool, the fixing means for fixing the second casing portion to the first casing portion is rotated to displace the second casing portion to a state where the cover is removable. With this configuration, it is not necessary to completely remove the fixing means and the second case portion from the first case portion, and it is possible to operate the inside of the case. Therefore, when the inside of the casing is operated for maintenance or the like of the power section in the casing, the loss of the fixing means can be prevented, and at the same time, the power section or other parts in the casing can be excessively exposed to the outside and the power section can be damaged Possibility. In addition, when returning to the original state of the clamping cover, it is not necessary to reattach the fixing means or the second housing part to the first housing part, and it is only necessary to rotate the fixing means, which can simplify the operation compared with the former. .

The fixing means may be a fixing screw that is screwed to the first housing portion and loosens when rotating in the first direction, and is locked when rotating in the second direction.

Furthermore, more specifically, the fixing screw has a shaft portion and a head portion; the second housing portion has: a through hole through which the shaft portion is inserted, and a concave portion connected to the through hole and receives the head portion, And a screw head engaging portion arranged to cover a part of the head and holding the head in the recess; when the fixing screw is loosened by screwing and rotating, the head of the fixing screw is stuck It is formed by engaging with the screw head engaging portion, and displacing the second housing portion in the distant direction. In addition, at this time, the screw head engaging portion may be provided in a ring shape with a central opening, and a tool is inserted through the central opening to perform a screwing rotation operation of the fixing screw.

In addition, the first housing portion may be provided as a resin-made internal extension portion screwed with the fixing screw, and the fixing screw is a tapping screw screwed into the internal extension portion.

With this configuration, in the manufacturing step of the first housing portion, it is not necessary to make the female screw of the screw-in fixing screw, and the manufacturing cost of parts can be reduced.

Furthermore, it may be provided that the first housing portion has a first locking portion, and the second housing portion has a second locking portion that is engaged with the first locking portion; The first locking portion and the The second locking portion is engaged to restrict a displacement range of the second housing portion with respect to the first housing portion in the distance direction, so that the fixing means does not move from the first within the displacement range. The shell part is completely detached.

Specifically, it may be provided that the second locking portion is a locking screw screwed into the second housing portion, and the first housing portion has a long hole that receives a front end portion of the locking screw, and the long hole. The end portion is provided as the first locking portion.

With this configuration, it is not necessary to displace the second housing portion by more than a necessary degree. In addition, since the fixing screw is not detached from the first housing portion, the loss of the fixing screw can be prevented more reliably.

Specifically, the power unit may be a commutating motor having a brush, and the brush may be disposed at a position that can be replaced through the opening for internal operation.

Hereinafter, embodiments of the power tool of the present invention will be described based on the attached drawings.

A power tool 10 according to an embodiment of the present invention is, as shown in FIGS. 1 to 3, an electric power tool including a commutating motor 14 as a power section in a housing 12. To the tool output shaft 20 that is driven to be connected to the rotary output shaft 16 of the commutating motor 14 via the bevel gear 18, necessary components such as a disc-shaped polishing pad can be mounted according to the application.

As shown in FIG. 3, the commutating motor 14 includes a rotor 22 rotatably mounted to the casing 12, a stator 24 disposed around the rotor 22 and fixed to the casing 12, and a rectifier mounted on the rotor 22. 23 brushes 26 are arranged in the way of contact. A switch 28 is mounted on the casing 12, and by operating this switch 28, the drive of the commutating motor 14 can be turned on / off. The brush 26 is gradually worn out due to sliding with the high-speed rotating rectifier 23. Therefore, after using the power tool 10 for a certain period of time, it needs to be replaced with a new brush 26.

The casing 12 includes a first casing portion 30 that holds the commutating motor 14, a second casing portion 32 mounted behind the first casing portion 30, and taps that fix the second casing portion 32 to the first casing portion 30. The screws (fixing means, fixing screws) 34 and two covers 36 that can be held between the first case portion 30 and the second case portion 32 and held. The second casing portion 32 is attached to the first casing portion 30 so that the front end portion 32a covers the outer peripheral surface 30a of the first casing portion 30, and is slidable in the direction of the long-side axis L with respect to the first casing portion 30. While shifting. Between the rear end recessed portion 30 b of the first casing portion 30 and the front end recessed portion 32 b of the second casing portion 32, an internal operation opening 37 is formed for operating the inside of the casing 12. This internal operation opening 37 is closed by a cover 36 in the use state of the power tool 10. The first housing portion 30 has an internal extension portion 38 extending into the second housing portion 32, and a hole 40 into which the tapping screw 34 is screwed is formed in the internal extension portion 38. The tapping screw 34 is screwed into the hole 40 while forming a thread on the side wall of the hole 40 of the internal extension 38, and is fixed. The entirety of the first housing portion 30 is made of resin so that the tapping screws 34 can be easily screwed into the internal extension portion 38.

The second housing portion 32 includes an insertion hole 46 through which the shaft portion 42 of the tapping screw 34 is inserted, a recessed portion 48 connected to the insertion hole 46 and receiving the head portion 44 of the tapping screw 34, and a long side. A metal engagement ring (screw head engagement portion) 50 made by pressing into the recessed portion 48 and fixing the peripheral portion of the head portion 44 of the tapping screw 34 in the direction of the axis L. The head 44 of the tapping screw 34 is held in the recessed portion 48 by the engaging ring 50. Therefore, the tapping screw 34 cannot be removed from the second housing portion 32. When the tapping screw 34 is fastened or loosened to the first housing portion 30, a tool such as a screwdriver is inserted through the central opening 52 of the engaging ring 50 to screw the tapping screw 34 into rotation. A groove may be provided on the inner peripheral surface of the recessed portion 48, and a stopper wheel may be fitted in the groove instead of pressing the engaging ring 50 into the recessed portion 48, thereby forming a screw head engaging portion.

A circuit board 60 is disposed on the inner extension portion 38 of the first case portion 30 so as to cover the second case portion 32. An LED 62 is mounted on the circuit board 60 to indicate the state of the power tool 10. This circuit board 60 is housed in a resin case, and can be mounted by sliding from the rear of the first housing portion 30 (the right side when viewed in the figure) toward the internal extension portion 38 of the first housing portion 30. A light diffusing member 64 for diffusing light from the LED 62 is disposed on the second housing portion 32 at a position matching the LED 62. Thereby, the light emitted from the LED 62 can be diffused by the light diffusing member 64, so that the outer surface of the light diffusing member 64 emits light with substantially uniform brightness, and it is easy to view the light emission of the LED 62.

As shown in FIG. 4, a locking screw (second locking portion) 54 that extends in a direction orthogonal to the long-side axis L is further screwed to the second housing portion 32. In addition, an elongated hole 56 extending in the direction of the long-side axis L is formed in the internal extension portion 38, and the elongated hole 56 receives the front end portion 58 of the locking screw 54.

As described above, the brushes 26 of the commutator motor 14 are worn due to friction with the commutator 23, and therefore need to be replaced regularly. In the power tool 10, the brush 26 can be replaced by the following steps.

First, as shown in FIG. 5, in a state where the second housing portion 32 is fixed to the first housing portion 30 by the tapping screws 34, the tapping screws 34 are screwed and rotated leftward (first direction) to loosen. slow. In this way, the tapping screw 34 is displaced from the first housing portion 30 along the long-side axis L in a direction away from the right (the right side when viewed in the figure). As shown in FIG. 6, the head 44 is engaged with the engaging ring. 50. When the tapping screw 34 is loosened further, the engaging ring 50 is pressed against the head 44 of the tapping screw 34 to displace the second housing portion 32 and the tapping screw 34 in a direction away from the first housing portion 30. When the second casing portion 32 is shifted to the position shown in FIG. 7, the clamping of the cover 36 formed by the first casing portion 30 and the second casing portion 32 is released. Thereby, as shown in FIG. 8, the cover 36 can be removed from between the first case portion 30 and the second case portion 32.

When the second housing portion 32 is located in the position shown in FIG. 7, as shown in FIG. 9, the front end portion 58 of the locking screw 54 is engaged with the end portion (the first locking portion) 66 of the long hole 56 to make the first The second case portion 32 cannot be moved further away from the first case portion 30. That is, the range of displacement of the second housing portion 32 relative to the first housing portion 30 is restricted by the locking screw 54 and the end portion 66 of the long hole 56. The tapping screw 34 has a length that does not disengage from the first housing portion 30 within this displacement range.

As shown in FIG. 8, when the cover 36 is removed, the internal operation opening 37 covered by the cover 36 and closed is exposed. The removal of the old brush 26 from the brush support frame 70 and the installation of the new brush 26 to the brush support frame 70 can be performed through this internal operation opening 37. Once the new brush 26 is mounted on the brush support frame 70, the cover 36 is mounted again, and the tapping screw 34 is screwed to the right (second direction) to be locked and locked. In this way, the tapping screw 34 is displaced in a direction approaching the first case portion 30, and is engaged with the second case portion 32 to displace the second case portion 32 in the approach direction. When the state in which the second case portion 32 is fixed to the fifth case of the first case portion 30 is returned to the state shown in FIG. 5, the cover 36 is once again held between the first case portion 30 and the second case portion 32. The replacement operation of the brush 26 is thus completed.

In this power tool 10, it is not necessary to remove a part of the second case portion 32 and the tapping screw 34 of the case 12 when replacing parts such as the brushes 26 disposed in the case 12. Therefore, components such as the circuit board 60 or the LED 62 disposed inside the case 12 are not exposed to the outside, and there is little concern that such components may be damaged. In addition, loss of the tapping screw 34 can be prevented. The tapping screw 34 is threaded while forming a thread on the inner peripheral surface of the hole of the other material. However, when the tapping screw is removed and installed in the same hole again, it may be in a different position from the previous one. Form a thread. In this way, the strength of the inner peripheral surface of the hole is reduced. After repeated several times, the inner peripheral surface may be damaged and eventually the tapping screw cannot be held. In the power tool 10, as described above, the brushes 26 and the like that can operate the inside of the housing 12 without removing the tapping screws 34 can prevent damage to the screw holes caused by the tapping screws 34. In addition, the locking screw 54 and the long hole 56 are used to limit the displacement range of the second housing portion 32, so that the tapping screw 34 cannot be removed, and erroneous removal of the tapping screw 34 does not occur. Avoid the above problems surely.

The power tool 10 according to one embodiment of the present invention has been described above, but the present invention is not limited to this, and various changes can be made. For example, the first housing portion 30 may be formed of resin as long as the internal extension portion 38 into which the tapping screw 34 is screwed is formed, and it is not necessary that the entire first housing portion 30 is made of resin. In addition, a normal screw may be used instead of the tapping screw 34 as a fixing screw for fixing the second housing portion 32 to the first housing portion 30. However, in this case, a female screw must be formed in the internal extension 38 in advance. In addition, a screw integrated with a washer may be used as the fixing screw, and the second housing portion 32 is not provided to hold the head portion 44 of the screw, but is provided to hold the washer. In addition, the fixing means of the second case portion 32 and the first case portion 30 may be provided other than screws. For example, a member having a protruding portion protruding radially outward on the shaft portion may be used as a fixing means, and a hole having an inclined groove (or a spiral groove) formed on the inner peripheral surface of the first housing portion may be formed in advance to engage By attaching the protruding portion of the fixing means to the inclined groove and rotating the fixing means, it can be set to be displaced in a direction away from and approaching the first housing portion. The present invention is not limited to a power tool provided with a commutating motor, and can be similarly applied to a power tool provided with other power units such as a brushless motor, an air motor, and an engine. In addition, power tools also include machine tools such as transportable or fixed-position drilling devices or drilling machines.

10‧‧‧Power Tools

12‧‧‧ shell

14‧‧‧ Commutating Motor (Power Division)

16‧‧‧rotating output shaft

18‧‧‧ bevel gear

20‧‧‧tool output shaft

22‧‧‧rotor

23‧‧‧ Rectifier

24‧‧‧ Stator

26‧‧‧Brushes

28‧‧‧Switch

30‧‧‧The first shell part

30a‧‧‧outer surface

30b‧‧‧ rear recess

32‧‧‧ 2nd housing section

32a‧‧‧Front end

32b‧‧‧Front recess

34‧‧‧Tapping screws (fixing screws)

36‧‧‧ Cover

37‧‧‧Opening for internal operation

38‧‧‧Internal extension

40‧‧‧hole

42‧‧‧ Shaft

44‧‧‧ Head

46‧‧‧Plug-in hole

48‧‧‧ recess

50‧‧‧ engagement ring (screw head engagement part)

52‧‧‧ opening

54‧‧‧ locking screw (second locking part)

56‧‧‧ long hole

58‧‧‧ front end

60‧‧‧circuit board

62‧‧‧LED

64‧‧‧light diffusion member

66‧‧‧End (1st stop)

70‧‧‧brush support

L‧‧‧long side axis

FIG. 1 is a side view of a power tool according to an embodiment of the present invention. Figure 2 is a top view of the power tool of Figure 1. FIG. 3 is a side cross-sectional view taken along line III-III of FIG. 2. FIG. 4 is a plan sectional view taken along line IV-IV of FIG. 3. FIG. 5 is a cross-sectional view of the first main part showing the removal operation of the cover. FIG. 6 is a cross-sectional view of the second main part showing the removal operation of the cover. FIG. 7 is a cross-sectional view of the third main part showing the removal operation of the cover. FIG. 8 is a cross-sectional view of the fourth main part showing the removal operation of the cover. FIG. 9 is a plan cross-sectional view taken along line IV-IV of FIG. 3 in a state where the second housing portion is shifted to the position of FIG. 7.

Claims (7)

A power tool is a power tool provided with a power section in a housing, the housing comprising: a first housing section; a second housing section provided to be displaceable relative to the first housing section; 2 The fixing means for fixing the housing part to the first housing part, the opening for internal operation for operating the inside of the housing, and the first housing part and the fixing part held by the fixing means. A cover is provided between the second casing portions to close the opening for internal operation. The fixing means is provided to be displaced in a direction away from the first casing portion when rotating in the first direction, and When rotating in a second direction that is opposite to the first direction, it is displaced in a direction close to the first housing portion; the fixing means is provided to rotate in the first direction and move away from the first housing portion. When the direction is shifted, the second housing portion is engaged in the distant direction to displace the second housing portion in the distant direction and release the clamping, so that the cover can be moved from the first housing portion to the first housing portion. The second housing part is detached; the fixing means is arranged to rotate in the second direction After rotating and moving in a direction close to the first housing portion, engaging with the second housing portion in the approaching direction causes the second housing portion to shift in the approaching direction, so that the cover can be clamped Between the first casing portion and the second casing portion; the fixing means is screwed to the first casing portion, and is loosened when rotating in the first direction, and locked when rotating in the second direction Screw; the second housing portion has a screw head engaging portion arranged to cover a part of the head of the fixing screw, and when the fixing screw is loosened by screwing and rotating, the head of the fixing screw is locked The screw head engaging portion is formed by displacing the second housing portion in the away direction; the screw head engaging portion is formed into a ring shape with a central opening, and a tool is inserted through the central opening to allow The screwing operation of the fixing screw is performed. The power tool according to claim 1, wherein the second housing portion has a through hole through which the shaft portion of the fixing screw is inserted, and a recessed portion connected to the through hole and receiving the head portion, and the screw head portion The engaging portion is arranged to hold the head in the recessed portion. The power tool according to claim 1 or 2, wherein the first housing portion has a resin-made internal extension portion screwed with the fixing screw, and the fixing screw is a tapping screw screwed into the internal extension portion. The power tool according to claim 1 or 2, wherein the first housing portion has a first locking portion, and the second housing portion has a second locking portion that engages with the first locking portion; The first locking portion is engaged with the second locking portion to limit a displacement range of the second housing portion with respect to the first housing portion in the distant direction, so that the fixing means is displaced in the displacement. Within the range, it does not completely separate from the first case portion. The power tool according to claim 4, wherein the second locking portion is a locking screw screwed into the second housing portion, and the first housing portion has a long hole that receives a front end portion of the locking screw. An end portion of the long hole is provided as the first locking portion. The power tool according to claim 1 or 2, wherein the power unit is a commutating motor having a brush, and the brush is disposed at a position that can be replaced through the opening for internal operation. A power tool is a power tool provided with a power section in a housing, the housing comprising: a first housing section; a second housing section provided to be displaceable relative to the first housing section; 2 The fixing means for fixing the housing part to the first housing part, the opening for internal operation for operating the inside of the housing, and the first housing part and the fixing part held by the fixing means. A cover is provided between the second casing portions to close the opening for internal operation. The fixing means is provided to be displaced in a direction away from the first casing portion when rotating in the first direction, and When rotating in a second direction that is opposite to the first direction, it is displaced in a direction close to the first housing portion; the fixing means is provided to rotate in the first direction and move away from the first housing portion. When the direction is shifted, the second housing portion is engaged in the distant direction to displace the second housing portion in the distant direction and release the clamping, so that the cover can be moved from the first housing portion to the first housing portion. The second housing part is detached; the fixing means is arranged to rotate in the second direction After rotating and moving in a direction close to the first housing portion, engaging with the second housing portion in the approaching direction causes the second housing portion to shift in the approaching direction, so that the cover can be clamped Between the first housing portion and the second housing portion; the first housing portion has a first locking portion, and the second housing portion has a second locking portion engaged with the first locking portion; The first locking portion is engaged with the second locking portion to limit the displacement range of the second housing portion with respect to the first housing portion in the distance direction, so that the fixing means is moved in the moving direction. It will not completely disengage from the first housing part within the range of position; the second locking part is a locking screw screwed to the second housing part, and the first housing part has a front end part for receiving the locking screw A long hole, and an end portion of the long hole is provided as the first locking portion.