KR102303876B1 - power tools - Google Patents

Abstract

It is an object of the present invention to provide a power tool capable of making access to the interior of the housing easier and safer. The present invention is a power tool (10) having a commutator motor (14) in a housing (12), the housing (12) having a first housing part (30) and movable relative to the first housing part (30) It has a second housing portion 32 , a tapping screw 34 for fixing them, and a cover 36 that is clamped between the first housing portion 30 and the second housing portion 32 . When the tapping screw 34 is loosened, the tapping screw 34 is displaced in a direction away from the first housing portion 30 to engage the engagement ring 50 of the second housing portion 32, and the second housing The part 32 is displaced in its away direction. Thereby, the cover 36 is in a detachable state. Moreover, when the tapping screw 34 is tightened, the 2nd housing part 32 is displaced by the tapping screw 34 in the direction approaching the 1st housing part 30, and the cover 36 returns to the pinched state. come.

Description

power tools

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

BACKGROUND ART In power tools having a power unit in a housing, in general, an operator disassembles the housing to perform maintenance of the power unit disposed in the housing. For example, Patent Document 1 discloses a grinder having a commutator motor as a power unit in a housing including a motor housing and a rear cover. In general, commutator motors are designed to supply current to the rotor by bringing carbon brushes into contact with the commutator rotating together with the rotor. There is a need. In this grinder, the carbon brush is replaced after removing the fixing screw fixing the rear cover to the motor housing and removing the rear cover.

Japanese Laid-Open Patent Publication No. 2007-152479

In the case of a power tool that needs to remove a part of the housing in order to perform maintenance of the power unit arranged in the housing, like the conventional grinder described above, there is a risk of losing the removed screw, and the screw that has been removed may be removed again. It is cumbersome as detailed work is required to install it. Moreover, since parts, such as an electronic circuit and wiring arrange|positioned in the housing, are exposed to the outside when a part of a housing is removed, there exists a possibility that these parts may be damaged.

In view of the problems of the prior art, an object of the present invention is to provide a power tool including a power unit in a housing, which can be accessed more easily and safely into the housing. .

That is, the present invention

A power tool having a power unit in a housing, the power tool comprising:

that housing,

a first housing part;

a second housing portion displaceable relative to the first housing portion;

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

an internal access opening for accessing the interior of the housing;

a cover which is pinched between the first housing portion and the second housing portion fixed by the fixing means and is adapted to close the inner access opening thereof;

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

When the fixing means is rotated in its first direction and displaced in a direction away from the first housing part, it engages with the second housing part in the direction away from it and displaces the second housing part in the direction away from the constriction. to release the cover, the cover being separable 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 approaching the first housing part, it engages the second housing part in the approaching direction and displaces the second housing part in the approaching direction. and wherein the cover is adapted to be constricted between the first housing portion and the second housing portion thereof.

In the power tool, the second housing portion is displaced by rotating the fixing means for fixing the second housing portion with respect to the first housing portion so that the cover can be removed. With such a structure, the access to the inside of the housing can be made without completely removing the fixing means and the second housing portion with respect to the first housing portion. Therefore, when accessing the inside of the housing for maintenance, etc. of the power unit in the housing, it is possible to prevent loss of the fixing means and to damage the power unit or the like by excessively exposing the power unit or other parts in the housing to the outside. It becomes possible to reduce In addition, when returning the cover to the original state in which the cover is clamped, there is no need to re-align and attach the fixing means or the second housing portion with respect to the first housing portion, and it is only necessary to rotate the fixing means. It becomes possible to make the work easier than that.

The fixing means may be a fixing screw that is screwed to the first housing portion and is loosened when rotated in its first direction and tightened when rotated in its second direction.

More specifically,

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

The second housing portion includes an insertion hole through which the shaft portion is inserted, a concave portion that connects to the insertion hole and receives the head portion, and is disposed to cover a part of the head portion and holds the head portion in the concave portion It has a screw head part engaging part,

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 direction away from it. Moreover, in this case, the screw head part engaging part becomes a ring shape which has a central opening, and it can insert a tool through the central opening, and it can make it possible to perform screw rotation operation of the fixing screw.

Further, the first housing portion may have a resin inner extension to which the set screw is screwed, and the set screw may be a tapping screw fitted into the inner extension.

According to such a structure, it becomes unnecessary to manufacture the female thread part to which a set screw is screwed in the manufacturing process of a 1st housing part, and it becomes possible to reduce component manufacturing cost.

Further, 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,

When the first locking portion and the second locking portion are engaged, the displacement range of the second housing portion with respect to the first housing portion is limited in the direction away from it, and within the displacement range, the fixing means is locked. 1 It can be made not to completely deviate from the housing part.

Specifically, the second locking part is a locking screw screwed to the second housing part, and the first housing part has an elongated hole for receiving the distal end of the locking screw, and the end of the long hole is the first It can be made into a locking part.

With such a configuration, the case of displacing the second housing portion more than necessary is eliminated. In addition, since the fixing screw does not deviate from the first housing portion, it is possible to more reliably prevent the fixing screw from being lost.

Specifically, the power portion is a commutator motor having a brush, and the brush may be disposed in an exchangeable position through the inner access opening thereof.

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

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 to FIGS. A necessary member, such as a disk-shaped polishing pad, is attached to the tool output shaft 20 drive-connected via the bevel gear 18 to the rotation output shaft 16 of the commutator motor 14 according to a use.

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

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

The second housing portion 32 has an insertion 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 connection with the insertion hole 46 . ), and a metal engagement fixed by being press-fitted into the recess 48 so as to cover the periphery of the head portion 44 of the tapping screw 34 in the direction of the longitudinal axis L. It has a ring (screw head part engaging part) 50. The head portion 44 of the tapping screw 34 is held in the concave portion 48 by the engagement ring 50 . Accordingly, the tapping screw 34 does not come off from the second housing part 32 . When tightening or loosening the tapping screw 34 with respect to the 1st housing part 30, a tool, such as a screwdriver, is inserted from the central opening 52 of the engagement ring 50, and the tapping screw 34 is screwed. rotate Further, instead of press-fitting the engaging ring 50 into the recessed portion 48, a groove is formed on the inner circumferential surface of the recessed portion 48, and a snap ring is fitted into the groove, thereby configuring the screw head engaging portion. You may.

On the inner extension 38 of the first housing portion 30 , the circuit board 60 is disposed so as to be covered by the second housing portion 32 . 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 a resin case, and slides against the inner extension 38 of the first housing part 30 from the rear (right side in the drawing) of the first housing part 30 . is installed with The light diffusion member 64 for diffusing the light of the LED 62 is arrange|positioned at the position which matches with the LED 62 in the 2nd housing part 32. As shown in FIG. Thereby, the light emitted by the LED 62 is diffused by the light diffusing member 64, the outer surface of the light diffusing member 64 is illuminated with a substantially uniform brightness, so that the light emission of the LED 62 is easily visually recognized. has been

As shown in FIG. 4 , a locking screw (second locking part) 54 extending in a direction orthogonal to the longitudinal axis L is further screwed into the second housing part 32 . In addition, an elongated hole 56 extending in the direction of the longitudinal axis L is formed in the inner extension 38 , and this elongated hole 56 receives the distal end 58 of the engaging screw 54 . .

As mentioned above, since the brush 26 of the commutator motor 14 wears out by the friction between the commutator 23, periodic replacement becomes necessary. In the said power tool 10, replacement|exchange of the brush 26 can be performed in the following procedure.

First, as shown in FIG. 5, from the state in which the 2nd housing part 32 is being fixed with respect to the 1st housing part 30 by the tapping screw 34, the tapping screw 34 is leftward (first direction) to loosen the screw. Then, the tapping screw 34 is displaced in the direction away from the first housing part 30 along the longitudinal axis L (the right side in the drawing), and as shown in FIG. 6 , the head part 44 engages. It is engaged with the dowel ring (50). Further, when the tapping screw 34 is loosened, the engaging ring 50 is pressed against the head portion 44 of the tapping screw 34 , so that the second housing portion 32 is brought together with the tapping screw 34 in the first It is displaced in a direction away from the housing part 30 . When the second housing part 32 is displaced to the position in FIG. 7 , the stenosis of the cover 36 by the first housing part 30 and the second housing part 32 is released. Thereby, it becomes possible to remove the cover 36 from between the 1st housing part 30 and the 2nd housing part 32, as shown in FIG.

In addition, when the second housing part 32 is in the position of FIG. 7 , as shown in FIG. 9 , the tip 58 of the locking screw 54 is the end (first locking part) 66 of the long hole 56 . ), so that the second housing part 32 cannot be displaced further in the direction away from the first housing part 30 . That is, the displacement range of the second housing portion 32 with respect to the first housing portion 30 is limited by the locking screw 54 and the end portion 66 of the long hole 56 . The tapping screw 34 has a length which does not deviate from the 1st housing part 30 in this displacement range.

As shown in FIG. 8 , when the cover 36 is removed, the internal access opening 37 covered and closed by the cover 36 appears. The detachment of the old brush 26 from the brush holder 70 and the mounting of the new brush 26 to the brush holder 70 can be effected through this inner access opening 37 . When the new brush 26 is mounted on the brush holder 70, the cover 36 is mounted again, and the tapping screw 34 is screwed in the right direction (second direction) to tighten it. Then, the tapping screw 34 is displaced in a direction approaching the first housing part 30 to engage the second housing part 32 and displaces the second housing part 32 in the approaching direction. . When the second housing part 32 is returned to the state of FIG. 5 in which it is fixed to the first housing part 30 , the cover 36 is again closed by the first housing part 30 and the second housing part 32 . become a state In this way, the replacement operation of the brush 26 is completed.

In the said power tool 10, when exchanging parts, such as the brush 26 arrange|positioned in the housing 12, the 2nd housing part 32 and the tapping screw 34 which are a part of the housing 12. no need to remove Therefore, components, such as the circuit board 60 and LED 62 arrange|positioned inside the housing 12, are not exposed to the outside, and there is little possibility that these components may be accidentally damaged. Moreover, loss of the tapping screw 34 can also be prevented. The tapping screw is inserted while forming a screw groove in the inner peripheral surface of the hole of the mating material. However, when the tapping screw installed once is removed and mounted in the same hole again, the screw groove may be formed at a different position from the previous time. In doing so, the strength of the inner peripheral surface of the hole is lowered, and if this is repeated several times, the inner peripheral surface is destroyed, and eventually the tapping screw may not be held. In the said power tool 10, since it is possible to access the brush 26 etc. inside the housing 12 without removing the tapping screw 34 as mentioned above, the screw hole by the tapping screw 34 is possible. damage can be prevented. Further, by limiting the displacement range of the second housing portion 32 by the locking screw 54 and the long hole 56, the tapping screw 34 cannot be removed, so that the tapping screw 34 is accidentally removed. It becomes possible to prevent the above-mentioned 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, Various changes are possible. For example, as for the first housing part 30, the inner extension part 38 into which the tapping screw 34 is inserted should just be formed of resin, and the whole of the first housing part 30 must be made of resin. there is no Moreover, as a fixing screw for fixing the 2nd housing part 32 with respect to the 1st housing part 30, it is also possible to use a normal screw instead of the tapping screw 34. As shown in FIG. However, in this case, it is necessary to form a female thread in advance in the inner extension 38 . Further, as the fixing screw, a screw having a washer integral therein may be used, and the second housing portion 32 may be configured to hold the washer instead of the head portion 44 of the screw. In addition, the fixing means of the 2nd housing part 32 and the 1st housing part 30 can also be made into things other than a screw. For example, by using a member having a projection protruding radially outward from the shaft portion as a fixing means, a hole having an inclined groove (or a spiral groove) is formed on the inner peripheral surface of the first housing portion, and the projection of the fixing means is placed in the inclined groove. It can also be set as the structure so that it is displaced in the direction away from and approaching with respect to the 1st housing part by mounting so that it may engage, and rotating a fixing means. This invention is not limited to the power tool provided with a commutator motor, It is similarly applicable also in the power tool provided with other power parts, such as a brushless motor, an air motor, and an engine. Moreover, machine tools, such as a portable type or stationary type drill apparatus and a drill press, are also contained as a power tool.

10: power tools
12: housing
14: commutator motor (power part)
16: rotation 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 periphery
30b: concave at the rear end
32: second housing part
32a: front end
32b: shear recess
34: tapping screw (set screw)
36 : cover
37: internal access opening
38: inner extension
40 : hole
42: shaft
44: head
46: insertion hole
48: recess
50: engagement ring (screw head portion engagement portion)
52: opening
54: locking screw (second locking part)
56: long hole
58: tip
60: circuit board
62: LED
64: light diffusion member
66: end (first locking part)
70: brush holder
L: length axis

Claims (8)

A power tool (10) having a power unit (14) in a housing (12), the power tool (10) comprising:
the housing,
a first housing part 30;
a second housing part (32) displaceable relative to the first housing part;
fixing means for fixing said second housing portion relative to said first housing portion;
an internal access opening (37) for accessing the interior of the housing;
a cover (36) narrowed between the first housing part and the second housing part fixed by the fixing means and adapted to close the inner access opening;
When the fixing means is rotated in a first direction, it is displaced in a direction away from the first housing part, and when it is rotated in a second direction opposite to the first direction, it is displaced in a direction closer to the first housing part. ,
When the fixing means is rotated in the first direction and displaced in a direction away from the first housing part, it engages with the second housing part in the away direction and displaces the second housing part in the away direction to cause the constriction. release, and the cover is detachable from between the first housing part and the second housing part,
When the fixing means is rotated in the second direction and displaced in a direction approaching the first housing part, it engages the second housing part in the approaching direction and displaces the second housing part in the approaching direction. and the cover is narrowed between the first housing part and the second housing part,
the fixing means is a fixing screw 34 screwed to the first housing part, loosened when rotated in the first direction, and tightened when rotated in the second direction,
The second housing portion has a screw head portion engaging portion (50) disposed so as to cover a part of the head portion of the fixing screw, and when the fixing screw is screwed and loosened, the head portion of the fixing screw is the screw head. engaged with the minor engagement portion and adapted to displace the second housing portion in the away direction;
and the screw head engaging portion has a ring shape having a central opening so that a tool can be inserted through the central opening to perform screw rotation operation of the set screw. The method of claim 1,
The second housing portion has an insertion hole (46) through which the shaft portion of the fixing screw is inserted, and a concave portion (48) connected to the insertion hole and receiving the head portion, and the screw head portion engaging portion and arranged to retain the head portion within the recess. 3. The method according to claim 1 or 2,
The power tool according to claim 1, wherein the first housing portion has a resin inner extension portion (38) to which the set screw is screwed, and the set screw is a tapping screw fitted into the inner extension portion. 3. The method according to claim 1 or 2,
the first housing portion has a first locking portion (66) and the second housing portion has a second locking portion (54) engaged with the first locking portion;
When the first locking part and the second locking part are engaged, the displacement range in the direction away from the first housing part is limited, and within the displacement range, the fixing means is moved to the second locking part. 1 A power tool that is not intended to completely disengage from the housing part. 5. The method of claim 4,
The second locking part is a locking screw screwed to the second housing part, and the first housing part has an elongated hole (56) for receiving the distal end (58) of the locking screw, and the end of the long hole is the A power tool having a first locking portion. 3. The method according to claim 1 or 2,
wherein the power unit is a commutator motor having a brush, wherein the brush is disposed in an exchangeable position through the interior access opening. A power tool (10) having a power unit (14) in a housing (12), the power tool (10) comprising:
the housing,
a first housing part 30;
a second housing part (32) displaceable relative to the first housing part;
fixing means for fixing said second housing portion relative to said first housing portion;
an internal access opening (37) for accessing the interior of the housing;
a cover (36) narrowed between the first housing part and the second housing part fixed by the fixing means and adapted to close the inner access opening;
When the fixing means is rotated in a first direction, it is displaced in a direction away from the first housing part, and when it is rotated in a second direction opposite to the first direction, it is displaced in a direction closer to the first housing part. ,
When the fixing means is rotated in the first direction and displaced in a direction away from the first housing part, it engages with the second housing part in the away direction and displaces the second housing part in the away direction to cause the constriction. release, and the cover is detachable from between the first housing part and the second housing part,
When the fixing means is rotated in the second direction and displaced in a direction approaching the first housing part, it engages the second housing part in the approaching direction and displaces the second housing part in the approaching direction. and the cover is narrowed between the first housing part and the second housing part,
the first housing portion has a first locking portion (66) and the second housing portion has a second locking portion (54) engaged with the first locking portion;
When the first locking part and the second locking part are engaged, the displacement range in the direction away from the first housing part is limited, and within the displacement range, the fixing means is moved to the second locking part. 1 Do not completely deviate from the housing,
The second locking part is a locking screw screwed to the second housing part, and the first housing part has an elongated hole (56) for receiving the distal end (58) of the locking screw, and the end of the long hole is the A power tool having a first locking portion. delete

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