WO2011000335A1

WO2011000335A1 - Power tool

Info

Publication number: WO2011000335A1
Application number: PCT/CN2010/074993
Authority: WO
Inventors: 霍立祥
Original assignee: 苏州宝时得电动工具有限公司
Priority date: 2009-07-03
Filing date: 2010-07-05
Publication date: 2011-01-06

Abstract

A power tool comprises a head shell (11) and a machine shell (12). A motor and a driving mechanism are provided inside the machine shell (12). An output shaft (14) extends from the head shell (11). By the driving of the motor and the torque transmission of the driving mechanism, the output shaft (14) performs a rotationally oscillating movement about its axis (L). Wherein, an elastic element is provided between the head shell (11) and the output shaft (14). The elastic element can effectively absorb the vibration occurred on the output shaft (14) and the vibration transferred to the output shaft (14) by the non-symmetrical balance attachments, thus weakening the vibration transferred to the head shell (11) by the output shaft (14), greatly improving the vibration problem occurred in the process of the use of a user, and improving the operating comforts.

Description

Power tools

The invention relates to a power tool, in particular to a hand-held swing type power tool.

Background technique

The multi-function machine is a common swing-type power tool in the industry, because its output shaft makes a rotary swing motion around the axis. Therefore, when different accessory heads are mounted on the output shaft, a variety of different operating functions, such as sawing, cutting, grinding, scraping, etc., can be implemented to suit different job requirements.

The more common multi-function machine currently on the market generally includes a motor. The motor shaft of the motor is connected with an eccentric pin, and a bearing is sleeved on the eccentric pin to form an eccentric wheel structure. When the motor shaft rotates, the eccentric structure can perform an eccentric rotational motion about the axis of the motor shaft. The output shaft of the multi-function machine is disposed perpendicular to the motor shaft, and a fixed fork assembly is connected to the output shaft, and the fork assembly is formed with two opposite extending arms, which surround the eccentric structure, and the two extending arms The inner side is in close contact with the bearing in the eccentric wheel structure, so that when the eccentric wheel is eccentrically rotated, the eccentric wheel structure drives the shifting fork to generate a horizontal oscillating motion, and the output shaft is fixedly connected by the shift fork and the output shaft. Rotate around its axis. In this way, after the different ends of the output shaft are connected with different attachment working heads, such as straight saw blades, circular saw blades, triangular sanding discs, etc., the multi-function machine can perform various operations.

However, since the eccentric pin is eccentrically arranged in the eccentric structure, it is inevitable that during the entire movement, a large vibration will be generated due to the eccentric action, and the vibration will always act on the eccentric structure and the eccentric wheel. Drive the fork assembly. Therefore, if the user uses the multi-function machine for a long time, it will have a large feeling of hand, which is not conducive to the user's use, and is also harmful to the user's hand health.

For this purpose, a solution is proposed in US Pat. No. 6,926,595 B, which discloses a damper mechanism in which a pair of springs, two ends of the spring, are provided correspondingly between the outside of the fork and the inside of the housing. They are respectively connected to the inner side of the casing and the outside of the fork, so that when the fork is oscillating, the vibration generated by the eccentric structure is first absorbed by the spring and weakened, and then transmitted to the casing, so that the user feels Greatly reduced.

However, this damping method mainly solves the vibration problem in the case of a machine or a symmetric balanced attachment working head, such as a triangular sanding disc. If the user adopts an asymmetric balanced attachment working head, such as straight Saw blade, this damping method can not play a shock absorption effect. Because, straight saw The point of action is located on one side of the output shaft, which itself is unbalanced during the swinging process, and also causes a large vibration, and this vibration is transmitted to the housing through the output shaft, which also causes the user to be in the long time. It gives a feeling of numbness after use.

Therefore, it is necessary to develop a power tool to solve the above problems.

Summary of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide a power tool that can effectively reduce the vibration generated on the output shaft and also reduce the vibration transmitted from the asymmetric balanced attachment to the output shaft.

In order to achieve the above object, the present invention provides a power tool including a head case and a casing, wherein the casing is internally provided with a motor and a transmission mechanism, and the output shaft is extended in the head casing, and the output shaft is in the Under the driving of the motor, the torque transmission of the transmission mechanism can make a rotary oscillating motion about its own axis, wherein an elastic element is disposed between the head shell and the output shaft.

Preferably, one end of the head shell extends with a side wall, and the side wall is formed with a receiving space for receiving the output shaft, and the elastic element is radially disposed in the receiving space and connected to the output. Between the shaft and the side wall.

Preferably, the side wall is disposed symmetrically with respect to the axis of the output shaft.

Preferably, the resilient element is a pair of springs arranged symmetrically with respect to the output shaft.

Preferably, the axis of the spring is disposed perpendicular to the centerline of the head casing.

Preferably, the two ends of the spring are respectively connected with a first fixing piece and a second fixing piece, wherein the first fixing piece is connected with the side wall of the head case, and the second fixing piece is connected with the output shaft.

Preferably, the first fixing piece and the second fixing piece each have two faces, one surface is extended with a boss to connect the spring, and the other side is extended with a pin.

Preferably, the side wall of the head shell is symmetrically disposed with two receiving slots, and each of the receiving slots is provided with a fixing hole, and the first fixing piece is received in the receiving slot and the first fixing piece is The pin is inserted into the fixing hole of the receiving groove.

Preferably, the output shaft is provided with a mounting hole, and the latch on the second fixing piece is inserted into the mounting hole on the output shaft.

Preferably, the elastic element is axially sleeved on the output shaft.

Preferably, the output shaft has a shaft body and a disk body having a larger radius than the shaft body, and the elastic element is axially sleeved on the shaft body of the output shaft, and the two ends of the elastic element are respectively connected to the output shaft The inner end surface of the disk body and the pressure plate which is also sleeved on the shaft body of the output shaft are closely fitted, and the pressure plate is fixed relative to the head case. Preferably, one end of the head shell extends with a side wall, and the side wall is formed with a receiving space for receiving the output shaft, and the side wall is disposed symmetrically with respect to an axis of the output shaft.

Preferably, the elastic element and the pressure plate are also located in the receiving space.

Preferably, the end of the elastic element is planar.

Preferably, the elastic element is a spring, a spring piece or a rubber pad.

In the power tool of the present invention, since the elastic member is disposed between the head shell and the output shaft, the vibration generated on the output shaft and the vibration transmitted from the asymmetric balance attachment to the output shaft can be effectively absorbed, thereby outputting The vibration transmitted to the head shell of the shaft is obviously weakened, which greatly improves the user's vibration and hand trouble during use, and improves the comfort of the operation.

DRAWINGS

Fig. 1 is a perspective view showing a power tool according to a first embodiment of the present invention, in which a seal ring in the head case has been removed.

Figure 2 is an exploded perspective view of the head shell portion of Figure 1.

Figure 3 is a top plan view of the head shell portion of Figure 1.

Figure 4 is a cross-sectional view along the axis Y of Figure 3.

Figure 5 is a reference view of the working state of the power tool shown in Figure 1, in which the output shaft is swung in a clockwise direction and is located in a coordinate quadrant formed by the center line X and the axis Y, and the spring portion of the second quadrant is In the contracted state, the spring portion of the first quadrant is in a stretched state, the spring portion of the fourth quadrant is in a contracted state, and the spring portion of the third quadrant is in a stretched state.

Figure 6 is a reference view of another working state of the power tool shown in Figure 1, in which the output shaft is swung in a counterclockwise direction and is located in a coordinate quadrant formed by the center line X and the axis Y axis, the third quadrant The spring portion is in a contracted state, and the spring portion of the fourth quadrant is in a stretched state, the spring portion of the first quadrant is in a contracted state, and the spring portion of the second quadrant is in a stretched state.

Figure 7 is a cross-sectional view showing the head case of the power tool in the second embodiment of the present invention.

Figure 8 is a perspective view of the head case of Figure 7, in which the seal ring in the head case has been removed. Figure 9 is an exploded perspective view of Figure 8.

Figure 10 is a partial enlarged view of Figure 7.

The corresponding component numbers in the illustration are as follows:

1 00, multi-function machine 1 1, head shell 1 2, case

1 4, output shaft 1 5, mounting hole 20, accommodating space

21, side wall 22, receiving groove 23, fixing hole 24, the first fixing piece 25, the first surface 26, the boss

27, the second side 28, the latch 29, the second fixed piece

30, spring 200, multi-function machine 41, head shell

42. Transmission 43, output shaft 431, shaft body

432, disk body 433, inner end surface 50, space

51, side wall 60, spring 61, pressure plate

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

First, a first embodiment of the present invention will be described in detail with reference to Figs. 1 to 6 .

Referring to FIG. 1 , a power tool disclosed in a first embodiment of the present invention is specifically a swing type power tool, that is, a multi-function machine 100 , which includes a head shell 1 1 and a substantially barrel disposed substantially in an angular direction. The casing 12 is connected by screws. A motor (not shown) is disposed in the casing 1 2, and a transmission (not shown) and an output shaft 1 4 are disposed in the head casing 1 1 , and the output shaft 14 has an axis L. The transmission is coupled to the motor to convert the rotational torque output by the motor into a rotational oscillating motion of the output shaft 1 4 about its axis L, as indicated by the direction of the double arrow in FIG. When the free end of the output shaft 14 is connected with different attachment working heads, such as a straight saw blade, a circular saw blade, a triangular sanding disc, etc., cutting or grinding operations can be realized.

Referring to FIG. 2 and FIG. 4, the head casing 1 1 includes two ports, one of which is fixedly connected to the casing 12 by screws, and the other port is provided with an annular side wall 21 and a side wall. 21 Containment has a receiving space 20. The output shaft 14 is disposed in the accommodating space 20, and the side wall 21 is disposed symmetrically with respect to the axis of the output shaft 14. In the accommodating space 20, on the side wall 21 of the output shaft 14 4, along the direction perpendicular to the center line X (see FIG. 3) of the head casing 1 1 , a receiving groove 22 is symmetrically disposed, and each receiving groove The center position of 22 is provided with a fixing hole 23. In the housing groove 22, a first fixing piece 24 can be inserted. The first fixing piece 24 is substantially square, has an opposite first surface 25 and a second surface 27, and a circular boss 26 extends toward the first surface 25 of the output shaft 14 and the second surface 27 A latch 28 is provided. When the first fixing piece 24 is inserted into the receiving groove 22, the plug 28 can be inserted into the fixing hole 23. Similarly, a pair of mounting holes 15 are symmetrically disposed on the output shaft 14, and a second fixing piece 29 is detachably connected to the output shaft 14. The second fixing piece 29 is also substantially square, and has the structure and the first The fixing pieces 24 are substantially the same, and have two faces, and are provided with a plug on the side facing the output shaft 14 and a circular boss on the other side. In addition, a first fixing piece 24 and a second fixing piece 29 are respectively disposed between A spring 30. The axis Y of the spring 30 is perpendicular to the center line X of the head casing 1 1 , and the two ends of the spring 30 are respectively connected to the boss 26 on the first fixing piece 24 and the boss on the second fixing piece 29. Therefore, the pair of springs 30 are housed in the accommodating space 20 in a symmetrical form.

In Fig. 3, according to the center line X of the head casing 1 and the axis Υ of the spring 30, a plane rectangular coordinate system can be constructed, and the coordinate origin is the intersection of the center line X and the axis ,, and along the origin and perpendicular to the The plane rectangular coordinate system extends the axis L of the output shaft 14. The plane rectangular coordinate system includes four quadrants defined as a first quadrant from the upper right and a counterclockwise rotation defined as a second quadrant, a third quadrant, and a fourth quadrant, respectively.

Referring to Figures 5 and 6, in Figure 5, the output shaft 14 is rotated clockwise relative to the initial position by an angle of less than 3 °. The initial position here is defined as the position of the output shaft 14 in relation to the head casing 1 1 in Fig. 3, at which point the opposite pair of apex angles of the regular hexagon on the output shaft 14 are located exactly on the center line X. When the output shaft 14 rotates, the portion of the spring 30 located in the second quadrant of the plane coordinate system is compressed, and the portion in the first quadrant is stretched; meanwhile, the portion of the spring 30 located in the fourth quadrant is subjected to Compressed, while the portion in the third quadrant is stretched. In Fig. 6, the output shaft 14 is rotated counterclockwise with respect to the initial position by an angle of less than 3 °. At this time, the portion of the spring 30 located in the third quadrant of the plane coordinate system is compressed, and the portion of the fourth quadrant is stretched; meanwhile, the portion of the spring 30 located in the first quadrant is compressed, and The part in the second quadrant is stretched. In this way, the vibration caused by the eccentric transmission of the transmission device or the vibration caused by the unbalanced attachment is absorbed and weakened by the spring 30, so that the vibration transmitted to the head casing 1 1 is greatly reduced, and the user can be effectively improved. Operational comfort.

Next, a second embodiment of the present invention will be described in detail with reference to Figs. 7 to 10 .

Referring to FIG. 7, the power tool disclosed in the second embodiment of the present invention is specifically a swing type power tool, that is, a multi-function machine 200, which includes a head shell 41 disposed substantially in an angular direction, in the head shell 41. A transmission 42 and an output shaft 43 are provided. The transmission 42 is coupled to a motor (not shown) that is powered by the power tool to convert the rotational torque output by the motor into a rotational oscillating motion of the output shaft 43 about its axis Μ. The output shaft 43 includes a cylindrical body 431 and a disk body 432 having a larger radius than the shaft body 431, wherein one side of the disk body 432 facing the head case 41 is an inner end surface 433. When the free end of the output shaft 43, that is, the outer end surface is connected with a different attachment working head, such as a straight saw blade, a circular saw blade, a triangular sanding disc, etc., cutting or grinding operations can be realized.

Referring to FIG. 8 and FIG. 9, the head shell 41 includes two ports, one of which has a ring extending The side wall 51 and the side wall 51 are accommodated to form a receiving space 50. The output shaft 43 is disposed in the accommodating space 50 and is located at an axial position with respect to the annular side wall 51. A spring 60 is further disposed on the output shaft 43. The two ends of the spring 60 are in close contact with a pressure plate 61 sleeved on the output shaft 43. The pressure plate 61 is similarly received in the accommodating space 50, and is opposite to the accommodating space 50. The head case 41 is fixed while the other end is in close contact with the inner end face 433 of the output shaft 43.

In operation, the power tool mainly suppresses the rotational swing of the output shaft 43 by the friction of the inner end surface 433 of the output shaft 43 and the end surface of the pressure plate 61 at both ends of the spring 60, thereby reducing the vibration of the output shaft 43. The torsion spring is very similar. That is, when the output shaft 43 generates a rotational swing, it is rubbed against the end surface 433 of the output shaft 43 by the spring 61 to generate a restraining force with respect to the rotational direction of the output shaft 43 to achieve the effect of absorbing vibration.

Please refer to Figure 10, which needs to be explained in order to achieve better shock absorption. The end of the spring 60 is smoothed and has a flat surface, which effectively enlarges the contact area between the spring 60 and the inner end surface 433 of the output shaft 43, thereby increasing the frictional force.

It should be noted that, in addition to the springs in the first and second embodiments described above, the elastic member of the present invention may be other elastic members which can perform the same function, such as a spring piece, a rubber pad or the like.

Claims

Claim

A power tool comprising a head case and a casing, wherein the casing is internally provided with a motor and a transmission mechanism, and an output shaft extends from the head casing, and the output shaft is driven by the motor The torque transmission of the transmission mechanism is rotatably oscillating about its own axis, and is characterized in that: an elastic element is disposed between the head shell and the output shaft.

2. The power tool according to claim 1, wherein: one end of the head shell extends with a side wall, and the side wall is formed with a receiving space for receiving the output shaft, the elastic element is radially And disposed in the receiving space and connected between the output shaft and the side wall.

3. The power tool according to claim 2, wherein: the side wall is disposed symmetrically with respect to an axis of the output shaft.

4. A power tool according to claim 2 wherein: said resilient member is a pair of springs arranged symmetrically with respect to the output shaft.

A power tool according to claim 4, wherein: the axis of said spring is disposed perpendicular to a center line of the head casing.

The power tool according to claim 5, wherein: the first fixing piece and the second fixing piece are respectively connected to the two ends of the spring, wherein the first fixing piece is connected to the side wall of the head case, The second fixing piece is connected to the output shaft.

7. The power tool according to claim 6, wherein: the first fixing piece and the second fixing piece each have two faces, one surface has a boss extending to connect the spring, and the other side is extended. Latch

The power tool according to claim 7, wherein: the side wall of the head shell is symmetrically disposed with two receiving slots, and each receiving slot is provided with a fixing hole, the first fixing piece The pin inserted in the receiving groove and the first fixing piece is inserted into the fixing hole of the receiving groove.

9. The power tool according to claim 8, wherein: the output shaft is provided with a mounting hole, and the latch on the second fixing piece is inserted into the mounting hole on the output shaft.

A power tool according to claim 1, wherein: said elastic member is axially disposed on said output shaft.

1 . The power tool according to claim 10, wherein: the output shaft has a shaft body and a disk body having a larger radius than the shaft body, and the elastic element is axially sleeved on the shaft of the output shaft. The two ends of the elastic member are respectively closely attached to the inner end surface of the disc body of the output shaft and the pressure plate which is also sleeved on the shaft body of the output shaft, and the pressure plate is fixed relative to the head shell.

The power tool according to claim 1 , wherein: one end of the head shell extends with a side wall, and the side wall is formed with a receiving space for receiving the output shaft, and the side wall is opposite The axis of the output shaft is symmetrically arranged in the center.

The power tool according to claim 12, wherein the elastic member and the pressure plate are located in the accommodating space.

A power tool according to claim 1, wherein the end of the elastic member is a flat surface.

The power tool according to any one of claims 1 to 2 or 10, wherein the elastic member is a spring, a spring piece or a rubber pad.