TW202112489A - Low-speed handheld power tool which is internally provided with a pneumatic motor, a planetary gear set, a bearing, a cushion block and a fixing seat - Google Patents

Abstract

A low-speed handheld power tool includes a housing, a middle cylindrical shell and a front cylindrical shell, all of which are screwed together, and is internally provided with a pneumatic motor, a planetary gear set, a bearing, a cushion block and a fixing seat, all of which are arranged adjacent to each other. The pneumatic motor is connected to the planetary gear set via a drive shaft, and the planetary gear set is connected to a bendable shaft via a driven shaft through a coupling so as to connect a grinding part in the fixing seat. The fixing seat is provided with an outer flange on the outer periphery thereof, and the front cylindrical shell is provided with an inner flange. The middle cylindrical shell is tightly locked by the front cylindrical shell so that the inner flange tightly presses the outer flange of the fixing seat and the fixing seat, the cushion block, the bearing, the planetary gear set and the pneumatic motor are firmly installed.

Description

Low-speed hand-held power tools

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

By the way, the surface of some workpieces needs to be ground with a small hand-held grinder. The conventional hand-held grinder has a motor and a grinding member that can pivot 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 shaft. The power output by the motor can be transmitted to the grinding member through the coupling member, and then drive the grinding member to rotate.

However, due to the very fast speed of the motor and the non-rigid structure of the coupling, the curved coupling will cause great wear during high-speed rotation, which is prone to failure and often needs to be replaced. On the other hand, the high-speed rotation of the motor drives the grinding piece to rotate at the same speed, and the surface of the ground workpiece is also quickly consumed. As long as the operator is careless, it may over-grind and damage the workpiece, which is inconvenient to use.

In view of this, how to improve the above-mentioned problem 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 being easy to operate and not damaging the workpiece.

To achieve the foregoing objective, the present invention provides a low-speed hand-held power tool, which includes: A casing, one end of which has a first opening and a first external threaded section, a pneumatic motor is arranged inside, and the pneumatic motor has a drive shaft extending out of the first opening; A middle cylindrical 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, and the third opening is provided with a first external thread section. Two external thread segments; A planetary gear set arranged in the intermediate cylinder includes a gear carrier pivoted with a plurality of planet gears and an outer gear ring, wherein each planet gear meshes with the drive shaft and the outer gear ring; the gear carrier There is a bearing adjacent to it, and a driven rotating shaft extends from the bearing; A spacer block, which is adjacent to the bearing in the intermediate shell and one end of which extends to the third opening; the spacer block is provided with a through hole, and a coupling connecting the driven shaft is provided in the through hole, the The coupling is further connected with a bendable shaft extending from the third opening; A fixed seat adjacent to the cushion block, and an outer flange is provided on the outer periphery of the fixed seat; A front cylindrical shell with a fourth opening and a fifth opening at both ends, the fourth opening is screwed to the second external thread section of the middle cylindrical shell with a second internal thread section, and the fifth opening is provided with a The inner flange is used to lock the middle cylinder shell by the front cylinder shell, so that the inner flange tightly presses the outer flange of the fixing seat, thereby making the fixing seat, the cushion block, the bearing, the planetary gear set and The pneumatic motor is stably arranged; the front cylinder shell is adjacent to one side cover ring; A grinding piece, which has a head for grinding a workpiece, the head is connected with a neck, the neck is connected with a spherical seat, the spherical seat is pivoted on the fixed seat with a pivot, so that the grinding piece can be Pivoting to adjust the working angle; the bendable shaft passes through the fixing seat and is connected to the grinding member; the neck extends out of the side cover ring, and is provided with a calibration part for judging the setting position of the grinding member; A control ring is arranged on the outer circumference of the fixing seat to position the grinding member after adjusting the working angle.

In one embodiment, a collar for assembling an auxiliary grip is provided on the outer periphery of the middle barrel shell.

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

It is not difficult to obtain an in-depth understanding of the above-mentioned objectives and advantages of the present invention from the detailed description of the selected embodiments and the accompanying drawings.

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. The exterior has a housing 11, a middle barrel 12, and a front barrel that are screwed together. The shell 13 has an air motor 2, a planetary gear set 3, a bearing 33, a spacer 4, and a fixing seat 5 adjacent to each other inside.

One end of the casing 11 has a first opening 111 and a first external 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.

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

The planetary gear set 3 is arranged in the intermediate cylinder housing 12, which includes a gear carrier 31 and an outer gear ring 32, wherein the drive shaft 21 extends into the gear carrier 31, and the gear carrier 31 is arranged around the drive shaft 21 There are three planetary gears 311, and each planetary gear 311 meshes with the drive shaft 21 respectively. On the other hand, the outer gear ring 32 surrounds the outer circumference of the gear carrier 31, and each planetary gear 311 meshes with the outer gear ring 32, respectively. A driven shaft 312 extends from the gear frame 31, and a bearing 33 is sleeved on the driven shaft 312. Accordingly, when the drive shaft 21 of the air motor 2 rotates, the planetary gears 311 are driven to rotate, and through their interaction with the outer gear ring 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 gear ring 32, the speed of the driven shaft 312 will be less than the speed of the drive shaft 21.

Since the total height of the planetary gear set 3 and the bearing 33 is smaller than the intermediate cylindrical shell 12, the spacer 4 is arranged at one end of the bearing 33, and one end of the spacer 4 can extend to the first end of the intermediate cylindrical shell 12. Three openings in 122 places. The spacer 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. 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 base 5 is adjacent to the cushion block 4, and an outer flange 52 is provided on its outer periphery. Both ends of the front shell 13 have a fourth opening 131 and a fifth opening 132 respectively. The fourth opening 131 is provided with a second internal threaded section 133, and the fifth opening 132 is provided with an inner flange 134. The front cylindrical shell 13 is screwed to the second external threaded section 124 of the middle cylindrical shell 12 by the second internal threaded section 133, and the inner flange 134 abuts against the outer flange 52 of the fixing base 5. With the front cylinder shell 13 locking the middle cylinder shell 12, the inner flange 134 tightly presses the outer flange 52, and the pressing force is successively transferred from the fixing seat 5 to the cushion block 4, the bearing 33. The planetary gear set 3 and the air motor 2 enable the above-mentioned components to be firmly fixed in the casing 11, the intermediate cylindrical shell 12 and the front cylindrical shell 13. In addition, the front cylinder shell 13 is adjacent to one side cover ring 15.

The fixing base 5 has a recess 53 for assembling a grinding piece 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. The spherical seat 63 is pivoted to the fixed seat by a pivot 51. In the recess 53 of 5, and connected with the bendable shaft 35, the grinding member 6 can be pivoted to adjust the working angle.

The above-mentioned neck 62 extends out of the side cover ring 15 and is provided with a calibration portion 622 for judging the orientation of the grinding 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 for judging whether the setting orientation is correct when assembling the abrasive member 6 . Since the calibration part 622 is exposed on the surface that is not blocked by other objects, the position of the calibration part 622 can be easily adjusted by visual inspection or by using a jig to determine the position of the polishing part 6, so that the position of the polishing part 6 can be easily adjusted. The pivot direction can be well matched with the position of the start switch 113 of the pneumatic motor 2 on the casing 11, which is convenient for operation.

The grinding member 6 can be positioned by a control ring 8 arranged on the outer periphery of the fixing base 5 after adjusting the working angle. As shown in Figure 4, the spherical seat 63 is provided with a plurality of ring grooves 64 on the outer circumference, and the two relative positions of the fixed seat 5 are respectively provided with a perforation 54, and each perforation 54 is provided with a ball 55, which can be When pushing inward from the outside of the fixed base 5, it moves toward the inside of the fixed base 5 in the perforation 54. A C-shaped ring 7 is provided on the outer periphery of the fixed seat 5, and a pressing portion 73 is respectively provided on the inner peripheral surface corresponding to the ball 55, thereby reducing the wear between the C-shaped ring 7 and the ball 55. The control ring 8 has an outer ring surface 81 in a perfect circular shape, and can be provided with anti-skid lines 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 grinding member 6, the control ring 8 controls the C-ring 7 to be opened, and the pressing portion 73 will not push the ball 55 inwardly, so that the ball 55 will not be pressed against the spherical seat On 63, according to this, the abrasive 6 can pivot between the orientations shown in Figures 5 and 6.

When the control ring 8 is rotated to lock the pivot angle of the grinding member 6, the control ring 8 pushes the C-shaped ring 7 to deform the inner clamp, and the pressing portion 73 pushes the ball 55 inwardly. 55 is further pressed against the ring groove 64 of the spherical seat 63 due to the pushing force, and the pivot angle of the grinding member 6 is fixed accordingly to perform processing operations.

In the present invention, the speed of the driven shaft 312 is reduced by the planetary gear set 3, so that the speed of the bendable shaft 35 is lower than the speed of the drive shaft 21 of the pneumatic motor 2. Accordingly, the loss of the bendable shaft 35 due to rotation is also reduced, so as to achieve the purpose of prolonging its service life. In addition, the grinding member 6 is driven by the bendable rotating shaft 35 at a lower speed, so the grinding speed of the workpiece is slow, and the operator can have ample margin to operate the tool, so as to avoid over-grinding negligence and damage 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 buckle 91 that can be toggled. By loosening the buckle 91 to unlock the polishing piece 6, on the contrary, the buckle 91 is fastened to lock the polishing piece 6 The pivot angle.

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

In summary, those skilled in the art can understand that this invention can clearly achieve the aforementioned purpose, and that it has actually complied with the provisions of the Patent Law, so it can file an application in accordance with the law.

１１:Chassis 111: The first opening 112: The first external thread section 113: Start switch 12: Intermediate cylinder shell 121: The second opening 122: The third opening 123: The first internal thread section 124: The second external thread section 13: Front tube shell 131: Fourth opening 132: Fifth opening 133: The second internal thread section 134: Inner flange 14: Ring 15: Side cover ring 2: Air motor 21: Drive shaft 3: Planetary gear set 31: Gear frame 311: Planetary gear 312: Driven shaft 32: External gear ring 33: Bearing 34: Coupling 35: Bendable shaft 4: Spacer 41: Through hole ５: Fixed seat 51: Pivot 52: Outer flange 53: Alcove 54: Piercing 55: Ball 6: Grinding parts 61: Head 62: Neck 621: arc surface 622: Calibration Department 63: Ball seat 64: Ring groove 7: C-ring 73: Pressure Department 8: Control ring 81: Outer ring surface 811: Anti-slip lines 82: Inner ring surface 9: Control ring 91: buckle

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

11: Chassis

111: The first opening

112: The first external thread segment

113: Start switch

12: Intermediate cylinder shell

121: second opening

122: third opening

123: The first internal thread segment

124: The second external thread section

14: collar

13: Front tube shell

131: The 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 frame

311: Planetary Gear

312: driven shaft

32: External gear ring

33: Bearing

34: Coupling

35: bendable shaft

4: spacer

41: Through hole

5: fixed seat

51: pivot

52: Outer flange

53: Alcove

6: Grinding parts

61: head

62: neck

621: arc surface

622: Calibration Department

63: ball seat

8: Control ring

Claims (4)

A low-speed hand-held power tool, which includes: A casing, one end of which has a first opening and a first external threaded section, a pneumatic motor is arranged inside, and the pneumatic motor has a drive shaft extending out of the first opening; A middle cylindrical 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, and the third opening is provided with a first external thread section. Two external thread segments; A planetary gear set arranged in the intermediate cylinder includes a gear carrier pivoted with a plurality of planet gears and an outer gear ring, wherein each planet gear meshes with the drive shaft and the outer gear ring; the gear carrier There is a bearing adjacent to it, and a driven rotating shaft extends from the bearing; A spacer block, which is adjacent to the bearing in the intermediate shell and one end of which extends to the third opening; the spacer block is provided with a through hole, and a coupling connecting the driven shaft is provided in the through hole, the The coupling is further connected with a bendable shaft extending from the third opening; A fixed seat adjacent to the cushion block, and an outer flange is provided on the outer periphery of the fixed seat; A front cylindrical shell with a fourth opening and a fifth opening at both ends, the fourth opening is screwed to the second external thread section of the middle cylindrical shell with a second internal thread section, and the fifth opening is provided with a The inner flange is used to lock the middle cylinder shell by the front cylinder shell, so that the inner flange tightly presses the outer flange of the fixing seat, thereby making the fixing seat, the cushion block, the bearing, the planetary gear set and The pneumatic motor is stably arranged; the front cylinder shell is adjacent to one side cover ring; A grinding piece, which has a head for grinding a workpiece, the head is connected with a neck, the neck is connected with a spherical seat, the spherical seat is pivoted on the fixed seat with a pivot, so that the grinding piece can be Pivoting to adjust the working angle; the bendable shaft passes through the fixing seat and is connected to the grinding member; the neck extends out of the side cover ring, and is provided with a calibration part for judging the setting position of the grinding member; A control ring is arranged on the outer circumference of the fixing seat to position the grinding member after adjusting the 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 barrel. The low-speed hand-held power tool according to claim 1, wherein the neck of the abrasive piece 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 and pivotally connect with the pivot, so that the spherical seat can pivot in the recess Pendulum; The spherical seat is provided with a plurality of ring grooves; the 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 peripheral surface of the ring is provided with a pressing portion respectively where the ball should be placed; the control ring surrounds the outer peripheral surface of the C-shaped ring with an inner ring surface, and rotating the control ring can switch the C-shaped ring open and inner The clamp is deformed. When the C-shaped ring is opened, the pressing part will not push against the ball, so that the grinding piece can pivot to adjust the working angle; when the C-shaped ring is deformed under pressure, the pressing part pushes against the ball. The ball, and then the ball is pressed against the annular groove of the spherical seat, thereby fixing the abrasive piece.

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