TWI696516B - Low-speed handheld power tools - Google Patents

Abstract

A low-speed hand-held power tool includes a case, a middle cylinder shell and a front cylinder shell which are screwed together, and an adjacent air motor, a planetary gear set, a bearing, a cushion and a fixed seat are arranged inside, wherein the air motor is A driving shaft is connected to the planetary gear set, and the planetary gear set is connected to a bendable rotating shaft through a coupling through a driven rotating shaft, and thereby connects the abrasive parts in the fixed seat. The outer periphery of the fixed seat is provided with an outer flange, and the front barrel shell is provided with an inner flange. Blocks, bearings, planetary gear sets and air motors are firmly installed.

Description

Low-speed handheld power tools

The invention relates to a hand-held power tool, especially a low-speed hand-held power tool.

Press, some workpiece surfaces need to be grinded using a small hand-held grinder. The conventional hand-held grinding machine has a motor and a grinding member that can be pivoted to adjust the working angle. In order to match the angle adjustment of the grinding member, the motor and the grinding member must be connected by a flexible connecting shaft member, then The power output by the motor can be transmitted to the grinding member through the connecting shaft member, thereby driving the grinding member to rotate.

However, due to the fast speed of the motor and the non-rigid structure of the coupling member, the curved coupling member will cause great wear and tear during high-speed rotation, so it is easy to malfunction and often needs to be replaced. On the other hand, the high-speed rotation of the motor drives the abrasive to rotate at the same speed, and the surface of the workpiece to be polished is also quickly consumed. As long as the operator is careless, it may over-grind and damage the workpiece, which is not convenient for use.

In view of this, how to improve the above problems is the primary problem to be solved by the present invention.

The main purpose of the present invention is to provide a low-speed hand-held power tool, which can reduce the loss of the rotating shaft to extend the service life, and at the same time has the effect of easy operation without harming the workpiece.

To achieve the foregoing objective, the present invention provides a low-speed handheld power tool, which includes: A casing with a first opening at one end and a first externally threaded section, with an air motor inside, the air motor having a drive shaft extending out of the first opening; A middle cylinder shell has a second opening and a third opening at both ends, the second opening is screwed to the first external thread section of the casing with a first internal thread section, the third opening is provided with a first Two external thread segments; A planetary gear set arranged in the middle cylinder shell includes a gear carrier pivotally provided with a plurality of planet gears and an external gear ring, wherein each planet gear meshes with the drive shaft and the external gear ring respectively; the gear carrier A bearing is adjacent to it, and a driven shaft extends from the bearing; A pad block adjoining the bearing in the middle cylinder shell and extending from one end to the third opening; the pad block is provided with a through hole, and a coupling coupling with the driven shaft is provided in the through hole, the The coupling is further connected with a bendable shaft extending out of the third opening; A fixed seat, which is adjacent to the pad, and an outer flange is provided on the outer periphery of the fixed seat; A front barrel shell has a fourth opening and a fifth opening at both ends, the fourth opening is screwed to the second external thread section of the middle barrel shell with a second internal thread section, the fifth opening is provided with a The inner flange locks the middle cylinder shell by the front cylinder shell, so that the inner flange tightly presses the outer flange of the fixing base, and then the fixing base, the pad, the bearing, the planetary gear set and The air motor is stably set; the front cylinder shell is adjacent to a side cover ring; An abrasive part having a head for grinding a workpiece, the head is connected to a neck, the neck is connected to a spherical seat, and the spherical seat is pivotally mounted on the fixed seat with a pivot so that the abrasive part can Pivoting to adjust the working angle; the bendable shaft passes through the fixing base and connects to the grinding element; the neck extends beyond the side cover ring, and a calibration portion for judging the orientation of the grinding element is provided; A control ring is arranged on the outer periphery of the fixing seat, and is used to position the grinding member after adjusting its working angle.

In one embodiment, the middle cylinder shell is provided with a collar for assembling the auxiliary grip on the outer periphery.

In one embodiment, the neck of the abrasive element has an arc surface, and the calibration portion is a flattened flat area on the arc surface.

However, it is not difficult to obtain an in-depth understanding from the following detailed description and drawings of the selected embodiments.

Please refer to Figures 1 to 3, which shows the first embodiment of the low-speed hand-held power tool provided by the present invention, which has a casing 11, a middle barrel 12 and a front barrel screwed together The shell 13 has an air motor 2 adjacent thereto, a planetary gear set 3, a bearing 33, a spacer 4 and a fixed seat 5.

One end of the casing 11 has a first opening 111 and a first externally threaded section 112, the air motor 2 is accommodated in the casing 11, and the air motor 2 has a drive shaft extending out of the first opening 111 21.

Two ends of the middle cylinder shell 12 have a second opening 121 and a third opening 122, wherein the second opening 121 is provided with a first internally threaded section 123, and the third opening 122 is provided with a second externally threaded section 124 , The middle cylinder shell 12 and the casing 11 are screwed with the first external thread section 123 and the first external thread section 112. The middle cylinder shell 12 is provided with a set of rings 14 on the outer periphery, which can be used to assemble an auxiliary grip (not shown in the figure), so that the operator can hold it stably.

The planetary gear set 3 is disposed in the intermediate cylinder shell 12 and includes a gear frame 31 and an external ring gear 32, wherein the drive shaft 21 extends into the gear frame 31, and the gear frame 31 is disposed around the drive shaft 21 There are three planet gears 311, and each planet gear 311 meshes with the drive shaft 21 respectively. On the other hand, the outer ring gear 32 surrounds the outer periphery of the carrier 31, and each planetary gear 311 meshes with the outer ring gear 32, respectively. The gear frame 31 protrudes a driven rotating shaft 312, and a bearing 33 is sleeved on the driven rotating shaft 312. According to this, when the drive shaft 21 of the air motor 2 rotates, each planetary gear 311 is driven to rotate, and by its interaction with the external ring gear 32, the gear carrier 31 and its driven shaft 312 rotate. Since the number of teeth of the planetary gear 311 is smaller than that of the outer ring gear 32, the rotational speed of the driven rotating shaft 312 will be smaller than the rotational speed of the driving shaft 21.

Since the total height of the planetary gear set 3 and the bearing 33 is less than that of the intermediate cylinder shell 12, the cushion block 4 is disposed at one end of the bearing 33, and one end of the cushion block 4 can extend to the first position of the intermediate cylinder shell 12 126 three openings. The pad 4 is provided with a through hole 41, the driven shaft 312 extends into the through hole 41, and is connected to a coupling 34, and the other end of the coupling 34 is connected to a bendable shaft 35. The above-mentioned bendable shaft 35 extends out of the third opening 122.

The fixing seat 5 is adjacent to the cushion block 4, and an outer flange 52 is provided on the outer periphery thereof. Both ends of the front barrel shell 13 respectively have a fourth opening 131 and a fifth opening 132, wherein the fourth opening 131 is provided with a second internally threaded section 133, and the fifth opening 132 is provided with an inner flange 134. The front barrel 13 is screwed to the second external thread 124 of the middle barrel 12 with the second internal thread 133, and the inner flange 134 abuts the outer flange 52 of the fixing base 5. By locking the middle cylinder shell 12 with the front cylinder shell 13, the inner flange 134 tightly presses the outer flange 52, and the pressing force is transmitted from the fixing base 5 to the pad 4 and the bearing 33. The planetary gear set 3 and the air motor 2 ensure that the above-mentioned components are stably fixed in the casing 11, the middle cylinder shell 12 and the front cylinder shell 13. The front cylinder shell 13 is adjacent to the side cover ring 15.

The fixing base 5 has a recess 53 for assembling an abrasive member 6. The grinding member 6 has a head 61 for grinding a workpiece, the head 61 is connected to a neck 62, the neck 62 is connected to a spherical seat 63, and the spherical seat 63 is pivotally mounted on the fixed seat with a pivot 51 The concave chamber 53 is connected to the bendable shaft 35 so that the grinding member 6 can pivot to adjust the working angle.

The neck portion 62 extends beyond the side cover ring 15 and is provided with a calibration portion 622 for judging the orientation of the abrasive member 6. In detail, the neck 62 has a circular arc surface 621, and the calibration portion 622 is a flattened flat area on the circular arc surface 621, so as to judge whether the setting orientation is correct when assembling the abrasive member 6 . Since the calibration part 622 is exposed on a surface that is not blocked by other objects, personnel can easily adjust the position of the calibration part 622 to determine the orientation of the abrasive member 6 by visually or using a jig, so that the abrasive member 6 The pivoting direction can be well matched with the position of the start switch 113 of the air motor 2 on the casing 11, which is convenient for operation.

After adjusting the working angle, the grinding member 6 can be positioned by a control ring 8 provided on the outer periphery of the fixing base 5. As shown in Fig. 4, the spherical seat 63 is provided with a plurality of ring grooves 64 on the outer periphery, and two fixed positions of the fixed seat 5 are respectively provided with a through hole 54, and each through hole 54 is provided with a ball 55, which can be When pushing inward from the outside of the fixing seat 5, it moves toward the inside of the fixing seat 5 in the through hole 54. The fixing seat 5 is provided with a C-shaped ring 7 on the outer periphery, and a pressing portion 73 is provided on the inner peripheral surface corresponding to the ball 55, according to which the wear between the C-shaped ring 7 and the ball 55 can be reduced. The control ring 8 has a perfect circular outer ring surface 81, and can be provided with a non-slip pattern 811, which surrounds the outer circumferential surface of the C-shaped ring 7 with an inner ring surface 82. When the control ring 8 is turned to unlock the abrasive member 6, the control ring 8 controls the C-shaped ring 7 to be opened, then the pressing portion 73 will not push the ball 55 inwards, so that the ball 55 will not be pressed against the spherical seat At 63, the abrasive member 6 can pivot between the orientations shown in Figures 5 and 6.

When the control ring 8 is rotated to lock the pivoting angle of the abrasive member 6, the control ring 8 pushes the C-shaped ring 7 to generate deformation of the inner clamp, and causes the pressing portion 73 to push inward against the ball 55. 55 is further pressed against the ring groove 64 of the spherical seat 63 due to the thrust, thereby fixing the pivoting angle of the abrasive member 6 to perform the processing operation.

In the present invention, the rotation speed of the driven shaft 312 is reduced by the planetary gear set 3, so that the rotation speed of the bendable shaft 35 is lower than the rotation speed of the drive shaft 21 of the air motor 2. Accordingly, the wear and tear caused by the rotation of the bendable shaft 35 is also reduced, so as to prolong its service life. In addition, the grinding member 6 is driven by the bendable shaft 35 at a lower rotational speed, so the grinding speed of the workpiece is slower, and the operator can have sufficient margin to operate the tool to avoid over-grinding and damage to the surface of the workpiece.

Figure 7 shows the second embodiment of the present invention. The difference between this embodiment and the aforementioned first embodiment lies in the structure of the control loop. In this embodiment, the control ring 9 has a movable buckle 91, which unlocks the abrasive member 6 by releasing the buckle 91, and conversely locks the abrasive member 6 by fastening the buckle 91 Pivot angle.

However, the disclosures of the above embodiments are only used to illustrate the present invention, not to limit the present invention, so the replacement of equivalent elements should still belong to the scope of the present invention.

In summary, those skilled in the art can understand that the present invention can indeed achieve the aforesaid objectives, which is in line with the provisions of the Patent Law, and file an application according to law.

11: Cabinet 111: The first opening 112: The first external thread segment 113: Start switch 12: Middle cylinder shell 121: Second opening 122: third opening 123: The first internal thread segment 124: Second external thread segment 13: front barrel shell 131: Fourth opening 132: Fifth opening 133: Second internal thread section 134: Inner flange 14: Collar 15: Side cover ring 2: Air motor 21: Drive shaft 3: Planetary gear set 31: Gear carrier 311: Planetary gears 312: driven shaft 32: External gear ring 33: Bearing 34: Coupling 35: Bending shaft 4: Pad 41: through hole 5: Fixed seat 51: Pivot 52: Outer flange 53: Alcove 54: Perforation 55: Ball 6: Abrasive parts 61: head 62: Neck 621: Circular surface 622: Calibration Department 63: spherical seat 64: Ring groove 7: C-ring 73: Pressure part 8: Control ring 81: outer torus 811: Anti-slip texture 82: inner torus 9: Control ring 91: buckle

Figure 1 is a perspective schematic view of the first embodiment of the present invention; Figures 2 and 4 are three-dimensional exploded schematic views of the first embodiment of the present invention; Figure 3 is a schematic cross-sectional view of the first embodiment of the present invention; Figures 5 and 6 are schematic cross-sectional views of the state of use of the fixed abrasive article of the invention; Figure 7 is a perspective schematic view of a second embodiment of the present invention.

11: Chassis

111: first opening

112: first external thread segment

113: Start switch

12: Middle cylinder shell

121: Second opening

122: third opening

123: first internal thread segment

124: second external thread segment

14: collar

13: front barrel shell

131: Fourth opening

133: second internal thread segment

132: Fifth opening

134: Inner flange

2: Air motor

21: Drive shaft

3: Planetary gear set

31: Gear rack

311: Planetary gear

312: driven shaft

32: External gear ring

33: Bearing

34: Coupling

35: bendable shaft

4: pad

41: through hole

5: fixed seat

51: pivot

52: outer flange

53: Alcove

6: abrasive parts

61: head

62: neck

621: Circular surface

622: Calibration Department

63: spherical seat

8: control ring

Claims (4)

A low-speed hand-held power tool, including: A casing with a first opening at one end and a first externally threaded section, with an air motor inside, the air motor having a drive shaft extending out of the first opening; A middle cylinder shell has a second opening and a third opening at both ends, the second opening is screwed to the first external thread section of the casing with a first internal thread section, the third opening is provided with a first Two external thread segments; A planetary gear set arranged in the middle cylinder shell includes a gear carrier pivotally provided with a plurality of planet gears and an external gear ring, wherein each planet gear meshes with the drive shaft and the external gear ring respectively; the gear carrier A bearing is adjacent to it, and a driven shaft extends from the bearing; A pad block adjoining the bearing in the middle cylinder shell and extending from one end to the third opening; the pad block is provided with a through hole, and a coupling coupling with the driven shaft is provided in the through hole, the The coupling is further connected with a bendable shaft extending out of the third opening; A fixed seat, which is adjacent to the pad, and an outer flange is provided on the outer periphery of the fixed seat; A front barrel shell has a fourth opening and a fifth opening at both ends, the fourth opening is screwed to the second external thread section of the middle barrel shell with a second internal thread section, the fifth opening is provided with a The inner flange locks the middle cylinder shell by the front cylinder shell, so that the inner flange tightly presses the outer flange of the fixing base, and then the fixing base, the pad, the bearing, the planetary gear set and The air motor is stably set; the front cylinder shell is adjacent to a side cover ring; An abrasive part having a head for grinding a workpiece, the head is connected to a neck, the neck is connected to a spherical seat, and the spherical seat is pivotally mounted on the fixed seat with a pivot so that the abrasive part can Pivoting to adjust the working angle; the bendable shaft passes through the fixing base and connects to the grinding element; the neck extends beyond the side cover ring, and a calibration portion for judging the orientation of the grinding element is provided; A control ring is arranged on the outer periphery of the fixing seat, and is used to position the grinding member after adjusting its working angle. The low-speed hand-held power tool according to claim 1, wherein a collar for assembling an auxiliary grip is provided on the outer periphery of the middle cylinder shell. The low-speed hand-held power tool according to claim 1, wherein the neck of the abrasive member has an arc surface, and the calibration portion is a flattened flat area on the arc surface. The low-speed hand-held power tool according to claim 1, wherein the fixing seat has a recess for the spherical seat of the grinding member to extend into and pivotally connect with the pivot shaft, so that the spherical seat can be pivoted in the center of the recess Pendulum; the spherical seat is provided with a plurality of ring grooves; two opposite sides of the fixed seat are respectively provided with a perforation, the perforation is provided with a ball that can slide along the perforation; the outer periphery of the fixed seat is provided with a C-shaped ring, the C The inner circumference of the ring-shaped ring is respectively provided with a pressing part; the control ring surrounds the outer circumferential surface of the C-shaped ring with an inner ring-shaped surface, and the control ring can be switched to open and close the C-shaped ring When the C-shaped ring is opened, the pressing portion will not push against the ball, so that the abrasive member can pivot to adjust the working angle; when the C-shaped ring is deformed under pressure, the pressing portion pushes against the ball The ball, thereby pressing the ball against the ring groove of the spherical seat, thereby fixing the abrasive.

Images