KR20190116429A - Power tools - Google Patents

Abstract

It is an object of the present invention to provide a power tool that can facilitate access to the inside of a housing more easily and safely. The present invention is a power tool (10) having a commutator motor (14) in a housing (12), the housing (12) being movable relative to the first housing portion (30) and the first housing portion (30). It has a 2nd housing part 32, the tapping screw 34 which fixes them, and the cover 36 clamped between the 1st housing part 30 and the 2nd housing part 32. As shown in FIG. When the tapping screw 34 is loosened, the tapping screw 34 is displaced in a direction away from the first housing portion 30 to be engaged with the engagement ring 50 of the second housing portion 32, and the second housing The part 32 is displaced in the direction away from it. As a result, the cover 36 is in a detachable state. Moreover, when the tapping screw 34 is tightened, the 2nd housing part 32 is displaced in the direction approaching the 1st housing part 30 by the tapping screw 34, and returns to the state which the cover 36 was clamped. come.

Description

Power tools

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

In a power tool provided with a power unit in a housing, generally, an operator can disassemble a housing and perform maintenance, such as a power unit arrange | positioned in a housing. For example, Patent Document 1 discloses a grinder including a commutator motor as a power unit in a housing formed of a motor housing and a rear cover. In general, the commutator motor is configured to supply a current to the rotor by bringing the carbon brush into contact with the commutator that rotates together with the rotor. However, the carbon brush gradually wears out due to friction with the commutator that rotates. There is a need. In this grinder, the carbon brush is replaced after the fixing screw that fixes the rear cover to the motor housing is removed and the rear cover is removed.

Japanese Unexamined Patent Publication No. 2007-152479

In a power tool that needs to remove a part of the housing in order to maintain the power unit arranged in the housing as in the conventional grinder described above, the screw may be lost and the screw removed once again may be lost. It requires a little work to put on, and it is cumbersome. In addition, when a part of the housing is removed, components such as electronic circuits and wirings disposed in the housing are exposed to the outside, which may cause damage to those components.

SUMMARY OF THE INVENTION An object of the present invention is to provide a power tool having a power unit in a housing, in view of the above-mentioned problems of the prior art, which can make access to the interior of a housing easier and safer. .

That is, the present invention,

A power tool having a power unit in a housing,

Its housing,

A first housing part,

A second housing portion that is displaceable relative to the first housing portion,

Fixing means for fixing the second housing portion to the first housing portion;

An internal access opening for accessing the interior of the housing,

A cover which is squeezed between the first housing portion and the second housing portion fixed by the fixing means and closes the inner access opening,

The fixing means is displaced in a direction away from the first housing part when rotated in the first direction, and displaced in a direction closer to the first housing part when rotated in a second direction opposite to the first direction. ,

When the fixing means is rotated in the first direction and displaced in a direction away from the first housing portion, the fixing means engages in the direction away from the second housing portion and displaces the second housing portion in the direction away from the second housing portion. And the cover is detachable from between the first housing portion and the second housing portion,

When the fixing means is rotated in the second direction and displaced in a direction closer to the first housing portion, the fixing means engages in the direction in which the second housing portion approaches the displacement and displaces the second housing portion in the direction closer thereto. And a power tool adapted to be squeezed between the first housing portion and the second housing portion.

In the said power tool, the 2nd housing part is displaced by rotating the fixing means which fixes the 2nd housing part with respect to a 1st housing part, and it is in the state which can remove a cover. With such a configuration, the fixing means and the second housing part can be made in a state in which the inside of the housing can be accessed without being completely removed from the first housing part. Therefore, when accessing the inside of the housing for maintenance of the power unit in the housing, etc., the fixing means is prevented from being lost, and the possibility of damaging the power unit or the like by excessively exposing the power unit or other parts in the housing to the outside is prevented. It becomes possible to reduce. Moreover, when returning to the original state in which the cover was constricted, it is not necessary to mount the fixing means and the second housing part again with respect to the first housing part, and only need to rotate the fixing means. In comparison, the operation can be facilitated.

The fixing means is screwed with respect to the first housing portion, and can be loosened when rotated in the first direction and tightened when rotated in the second direction.

More specifically,

The fixing screw has a shaft portion and a head portion,

The second housing portion includes an insertion through hole through which the shaft portion is inserted, a recess in contact with the insertion through hole to receive the head portion, and a portion of the head portion to cover the head portion to hold the head portion in the recess. With screw head fittings,

When the fixing screw is screwed and loosened, the head portion of the fixing screw is engaged with the screw head portion engaging portion, and the second housing portion can be displaced in the distant direction. In this case, the screw head engaging portion may be in a ring shape having a center opening, so that the tool can be inserted through the center opening so that the screw can be rotated.

In addition, the first housing portion may have an internal extension portion made of resin to which the fixing screw is screwed, and the fixing screw may be a tapping screw inserted into the internal extension portion.

With such a configuration, it is not necessary to produce the female screw portion to which the fixing screw is screwed in the manufacturing process of the first housing portion, and it is possible to reduce the component manufacturing cost.

Furthermore, the 1st housing part has a 1st locking part, and the 2nd housing part has a 2nd locking part which engages with the 1st locking part,

By engaging the first catching portion and the second catching portion, the range of displacement in the direction away from the second housing portion relative to the first housing portion is limited, and the fixing means is within the range of the displacement. 1 It can be prevented from completely deviating from the housing part.

Specifically, the second locking portion is a locking screw screwed to the second housing portion, and the first housing portion has a long hole that receives the tip of the locking screw, and the end of the long hole is the first screw. It can be made into a locking part.

With such a configuration, the second housing portion is no longer displaced than necessary. Moreover, since the fixing screw does not deviate from the first housing part, it becomes possible to more reliably prevent the loss of the fixing screw.

Specifically, the power unit can be a commutator motor having a brush, and the brush can be arranged at a position that can be exchanged through its internal access opening.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of the power tool which concerns on this invention is described based on an accompanying drawing.

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

The power tool 10 which concerns on one Embodiment of this invention is a power tool provided with the commutator motor 14 as a power part in the housing 12, as shown in FIGS. The tool output shaft 20 which is drive-connected to the rotational output shaft 16 of the commutator motor 14 via the bevel gear 18 is equipped with necessary members, such as a disk-shaped polishing pad, according to a use.

As shown in FIG. 3, the commutator motor 14 is disposed around the rotor 22 so as to be rotatable with respect to the housing 12, and is fixed to the housing 12 around the rotor 22. The stator 24 and two brushes 26 arranged to contact the commutator 23 mounted on the rotor 22 are provided. The switch 12 is attached to the housing 12, and the drive of the commutator motor 14 is turned ON / OFF by operating this switch 28. As shown in FIG. Since the brush 26 slides with the commutator 23 rotating at a high speed, the brush 26 gradually wears out. Therefore, when the power tool 10 is used for some time, it is necessary to replace it with a new brush 26.

The housing 12 includes a first housing part 30 holding the commutator motor 14, a second housing part 32 mounted behind the first housing part 30, and a second housing part 32. ) Two tapping screws (fixing means, fixing screws) 34 for fixing the first housing part 30 to the first housing part 30, and two clamped and held between the first housing part 30 and the second housing part 32. Has a cover 36. The 2nd housing part 32 is attached to the 1st housing part 30 so that the front part 32a may cover the outer peripheral surface 30a of the rear end part of the 1st housing part 30, and the 1st housing part It slides in the direction of the longitudinal axis L with respect to the 30, and is displaceable. An internal access opening 37 for accessing the inside of the housing 12 is formed between the rear end recess 30b of the first housing portion 30 and the front end recess 32b of the second housing portion 32. It is. This internal access opening 37 is closed by the cover 36 in the use state of the power tool 10. The first housing portion 30 has an internal extension portion 38 that extends into the second housing portion 32, and the internal extension portion 38 has a hole 40 into which the tapping screw 34 is fitted. Formed. The tapping screw 34 is sandwiched and fixed in this hole 40 while forming a screw groove in the side wall of the hole 40 of the inner extension 38. As for the 1st housing part 30, the whole is formed with resin, and it is easy to insert the tapping screw 34 in the internal extension part 38. As shown in FIG.

The second housing portion 32 has an insertion through hole 46 through which the shaft portion 42 of the tapping screw 34 is inserted, and a head portion 44 of the tapping screw 34 in contact with the insertion through hole 46. ) Is engaged with a metal, which is press-fitted into the recess 48 so as to cover the recess 48 and the peripheral portion of the head 44 of the tapping screw 34 in the direction of the length axis L. A ring (screw head engaging portion) 50. The head 44 of the tapping screw 34 is held in the recess 48 by the engagement ring 50. Therefore, the tapping screw 34 is prevented from coming off from the second housing part 32. When the tapping screw 34 is tightened or loosened with respect to the first housing part 30, a tool such as a screwdriver is inserted from the center opening 52 of the engagement ring 50, and the tapping screw 34 is screwed. Rotate In addition, instead of the structure which press-fits the engagement ring 50 to the recessed part 48, a groove | channel is formed in the inner peripheral surface of the recessed part 48, and a snap ring is inserted in the groove, and a screw head part engaging part is comprised. You may.

On the internal extension part 38 of the 1st housing part 30, the circuit board 60 is arrange | positioned so that the 2nd housing part 32 may be covered. The circuit board 60 is equipped with an LED 62 for displaying the state of the power tool 10. This circuit board 60 is put in the case made of resin, and slides with respect to the internal extension part 38 of the 1st housing part 30 from the back (right side of the figure) of the 1st housing part 30. FIG. Is mounted. The light diffusion member 64 for diffusing the light of the LED 62 is disposed at the position that matches the LED 62 in the second housing portion 32. As a result, the light emitted from the LED 62 is diffused by the light diffusing member 64, so that the outer surface of the light diffusing member 64 shines with a substantially uniform brightness, so that the light emission of the LED 62 is easy to be visually recognized. It is.

As shown in FIG. 4, the second housing part 32 is further screwed with a locking screw (second locking part) 54 extending in a direction orthogonal to the length axis L. As shown in FIG. Moreover, the long hole 56 extended in the direction of the longitudinal axis L is formed in the internal extension part 38, and this long hole 56 is made to receive the front-end | tip part 58 of the screw 54 for fastening. .

As mentioned above, since the brush 26 of the commutator motor 14 wears out by friction with the commutator 23, periodic replacement is necessary. In the power tool 10, the brush 26 can be replaced in the following order.

First, as shown in FIG. 5, the tapping screw 34 is turned to the left side (first first) from the state in which the second housing portion 32 is fixed to the first housing portion 30 by the tapping screw 34. Direction) to loosen the screw. In doing so, the tapping screw 34 is displaced in the direction away from the first housing part 30 along the longitudinal axis L (right side in the drawing), and as shown in FIG. 6, the head part 44 hangs. Is fitted to the fitting 50. In addition, when the tapping screw 34 is loosened, the engagement ring 50 is pressed against the head portion 44 of the tapping screw 34 so that the second housing portion 32 together with the tapping screw 34 firstly. It is displaced in the direction away from the housing part 30. When the second housing portion 32 is displaced to the position in FIG. 7, the narrowing of the cover 36 by the first housing portion 30 and the second housing portion 32 is released. Thereby, as shown in FIG. 8, the cover 36 can be removed from between the 1st housing part 30 and the 2nd housing part 32. As shown in FIG.

In addition, when the 2nd housing part 32 is in the position of FIG. 7, as shown in FIG. 9, the front-end | tip part 58 of the locking screw 54 will be the end part (1st locking part) 66 of the long hole 56. As shown in FIG. ), The second housing portion 32 can no longer be displaced in a direction away from the first housing portion 30. That is, the range of displacement of the 2nd housing part 32 with respect to the 1st housing part 30 is restrict | limited by the locking screw 54 and the edge part 66 of the long hole 56. The tapping screw 34 has a length that does not deviate from the first housing part 30 within this displacement range.

As shown in FIG. 8, when the cover 36 is removed, the internal access opening 37 that is covered and closed by the cover 36 appears. The removal of the old brush 26 from the brush holder 70 and the attachment of the new brush 26 to the brush holder 70 can be carried out via this internal access opening 37. If the new brush 26 is attached to the brush holder 70, the cover 36 is again mounted and the tapping screw 34 is screwed in the right direction (second direction) to tighten. In doing so, the tapping screw 34 is displaced in a direction closer to the first housing part 30, engages in the second housing part 32, and displaces the second housing part 32 in the direction in which it approaches. . When the second housing part 32 is returned to the state in FIG. 5 where the second housing part 32 is fixed to the first housing part 30, the cover 36 is again clamped by the first housing part 30 and the second housing part 32. It becomes a state. The replacement work of the brush 26 is completed by this.

In the said power tool 10, when replacing parts, such as the brush 26 arrange | positioned in the housing 12, the 2nd housing part 32 which is a part of the housing 12, and the tapping screw 34 are carried out. There is no need to remove it. Therefore, the components, such as the circuit board 60, LED 62, etc. which are arrange | positioned inside the housing 12 are not exposed to the outside, and there is little possibility that these components will be accidentally damaged. It is also possible to prevent the tapping screw 34 from being lost. The tapping screw is inserted while forming a screw groove in the inner circumferential surface of the hole of the mating material. If the attached tapping screw is removed and mounted in the same hole again, the screw groove may be formed at a position different from the previous time. As a result, the strength of the inner circumferential surface of the hole decreases, and if such a repetition is repeated several times, the inner circumferential surface may be broken and finally the tapping screw may not be held. In the said power tool 10, as mentioned above, since it is possible to access the brush 26 etc. of the inside of the housing 12, without removing the tapping screw 34, the screw hole by the tapping screw 34 Damage can be prevented. In addition, the tapping screw 34 is accidentally detached by restricting the displacement range of the second housing part 32 by the locking screw 54 and the long hole 56 so that the tapping screw 34 cannot be removed. It does not become a case, and it becomes possible to prevent the said problem more reliably.

Although the power tool 10 which concerns on one Embodiment of this invention was demonstrated, this invention is not limited to this, A various change is possible. For example, as for the 1st housing part 30, the internal extension part 38 to which the tapping screw 34 is fitted should just be formed of resin, and the whole 1st housing part 30 must necessarily be resin. There is no. As a fixing screw for fixing the second housing portion 32 to the first housing portion 30, a conventional screw may be used instead of the tapping screw 34. In this case, however, it is necessary to form a female screw in the internal extension portion 38 in advance. Further, as the fixing screw, a screw in which the washer is integrated may be used, and the second housing portion 32 may be configured to hold the washer instead of the head 44 of the screw. Moreover, the fixing means of the 2nd housing part 32 and the 1st housing part 30 can also be other than a screw. For example, using the member which has the projection which protruded radially outward in the axial part as a fixing means, the hole in which the inclined groove (or the spiral groove | channel) was formed in the inner peripheral surface of a 1st housing part is formed, and the projection part of a fixing means is formed in the inclined groove. It can also be set so that it may be mounted so that it may engage, and it may be displaced in the direction away from and closer to a 1st housing part by rotating a fixing means. This invention is not limited to the power tool provided with a commutator motor, It is similarly applicable to the power tool provided with other power parts, such as a brushless motor, an air motor, and an engine. Moreover, as a power tool, machine tools, such as a portable or stationary drill apparatus and a drill press, are also included.

10: power tool
12: housing
14: commutator motor (power unit)
16: rotating output shaft
18: Bevel Gear
20: tool output shaft
22: rotor
23: commutator
24: stator
26: brush
28: switch
30: first housing part
30a ： Outer circumference
30b: rear recess
32: second housing portion
32a: shear section
32b: shear recess
34: tapping screw (fixed screw)
36: cover
37: internal access opening
38: internal extension
40: hole
42: shaft portion
44: head
46: insertion hole
48: recess
50: engaging ring (screw head engaging part)
52: opening
54: catching screw (second catching part)
56: longevity
58: tip
60: circuit board
62: LED
64: light diffusing member
66: end (first catch)
70: brush holder
L: length axis

Claims (8)

A power tool having a power unit in a housing,
The housing,
A first housing part,
A second housing portion that is displaceable relative to the first housing portion,
Fixing means for fixing the second housing portion to the first housing portion;
An internal access opening for accessing the interior of the housing,
A cover squeezed between the first housing portion and the second housing portion fixed by the fixing means, the cover adapted to close the internal access opening,
The fixing means is displaced in a direction away from the first housing part when rotated in the first direction, and displaced in a direction approaching the first housing part when rotated in a second direction opposite to the first direction. ,
When the fixing means is rotated in the first direction and displaced in a direction away from the first housing part, the fixing means engages in the direction away from the second housing part and displaces the second housing part in the direction away from the stenosis. And the cover is detachable from between the first housing portion and the second housing portion,
When the fixing means is rotated in the second direction and displaced in the direction of approaching the first housing part, the fixing means engages in the direction of approaching the second housing part and displaces the second housing part in the approaching direction. And the cover is squeezed between the first housing portion and the second housing portion. The method of claim 1,
And the fixing means is a fixing screw that is screwed with respect to the first housing portion and that is loosened when rotated in the first direction and tightened when rotated in the second direction. The method of claim 2,
The fixing screw has a shaft portion and a head portion,
The second housing portion includes an insertion through hole through which the shaft portion is inserted, a concave portion connected to the insertion through hole to receive the head portion, and disposed to cover a portion of the head portion to hold the head portion in the concave portion. With screw head fittings,
And the head of the fixing screw is engaged with the screw head portion engaging portion when the fixing screw is screwed and loosened so as to displace the second housing portion in the away direction. The method of claim 3, wherein
And the screw head engaging portion is formed in a ring shape having a center opening so that a screw rotation operation of the fixing screw can be performed by inserting the tool through the center opening. The method according to any one of claims 2 to 4,
The power tool according to claim 1, wherein the first housing portion has an internal extension portion made of resin to which the fixing screw is screwed on, and the fixing screw is fitted into the internal extension portion. The method according to any one of claims 1 to 5,
Wherein the first housing portion has a first locking portion, the second housing portion has a second locking portion engaged with the first locking portion,
By engaging the first locking portion and the second locking portion, the displacement range in the away direction of the second housing portion relative to the first housing portion is limited, and the fixing means is within the displacement range. 1 Power tool, which is not completely out of the housing portion. The method of claim 6,
The second locking portion is a locking screw screwed to the second housing portion, the first housing portion has a long hole for receiving a tip of the locking screw, and an end of the long hole is the first locking portion. , Power tools. The method according to any one of claims 1 to 7,
And a power commutator motor having a brush, wherein the brush is disposed at a position that is replaceable through the internal access opening.

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