CN101780668A

CN101780668A - Power tool

Info

Publication number: CN101780668A
Application number: CN200910029078A
Authority: CN
Inventors: 毋宏兵; 龙强
Original assignee: Positec Power Tools Suzhou Co Ltd
Current assignee: Positec Power Tools Suzhou Co Ltd
Priority date: 2009-01-19
Filing date: 2009-01-19
Publication date: 2010-07-21

Abstract

The invention relates to a power tool which comprises a casing, a motor arranged in the casing, a main shaft driven by the motor and an eccentric driving mechanism connected to the main shaft, wherein the eccentric driving mechanism comprises an eccentric part connected to the main shaft and a shifting fork connected to the eccentric part; the shifting fork reciprocates through the rotation of the eccentric part on the main shaft, a driving shaft is pivotally connected to the other end of the shifting pork, and the driving shaft drives a tool head to swing through the motion of the shifting fork; and the eccentric part comprises an outer ring, an inner ring and a rolling part arranged between the outer ring and the inner ring, wherein an inner hole of the inner ring of the eccentric part is eccentrically arranged relative to the eccentric part. The power tool avoids machining an eccentric shaft, ensures that an eccentric mechanism is easy to be machined, reduces the manufacturing cost of the eccentric mechanism and increases the driving reliability.

Description

Power tool

Technical field

The present invention relates to a kind of power tool, especially a kind of power tool with eccentric drive mechanism.

Background technology

Traditional power tool with eccentric drive mechanism has casing, be arranged on the motor in the casing, by motor-driven main shaft, thereby the rotational motion of main shaft is converted to the rotation driven tool oscillating motion of driving shaft by being arranged on the eccentric stiffener on the main shaft.

U.S. Pat RE36909 discloses a kind of drives structure of electric tool, comprise casing, be arranged on the motor in the casing, by motor-driven main shaft, main shaft has the eccentric part of a rotation and the setting of offset rotation axis, one shift fork is connected on the working cell by main shaft drives and manipulation, one end pivoting of shift fork is connected on the driving shaft, the other end is formed with the fork shape of a pair of branch and is stuck on the eccentric part on the main shaft, driving shaft is vertical substantially with the main axis rotation axis, eccentric part and shift fork have two contact portions, at least one contact portion has curved surface, moves along the pivot of driving shaft and makes driving shaft move and the work of driven tool head thereby main shaft converts shift fork to around the rotation of rotation.

Though above-mentioned power tool with eccentric drive mechanism can be realized the eccentric gearing of power tool, but because its motor-driven main shaft is an eccentric shaft, the eccentric shaft processing difficulties, and machining accuracy is not high, cause eccentric drive mechanism manufacturing cost height, in transmission process, be easy to generate bearing and fall apart, brought inconvenience to the operator.

For this reason, prior art is necessary further improvement in fact.

Summary of the invention

At the deficiencies in the prior art, the object of the present invention is to provide a kind of power tool that does not need to process eccentric shaft and reliable transmission with eccentric drive mechanism.

The technical solution adopted for the present invention to solve the technical problems is: a kind of power tool, comprise casing, be arranged on the motor in the casing, by motor-driven main shaft, and be connected eccentric drive mechanism on the main shaft, described eccentric drive mechanism comprises the eccentric part that is connected on the main shaft, be connected the shift fork on the eccentric part, described shift fork moves back and forth by the rotation of the eccentric part on the main shaft, the other end of described shift fork is pivotally connected driving shaft, thereby described driving shaft is by the oscillating motion of shift fork motion driven tool, described eccentric part comprises the outer ring, inner ring and be arranged on the outer ring and inner ring between rolling member, the endoporus of the inner ring of described eccentric part is with respect to the eccentric setting of eccentric part.

The invention has the beneficial effects as follows: power tool of the present invention has avoided carrying out the processing of eccentric shaft by setting-up eccentricity spare on main shaft, makes the handling ease of eccentric stiffener, has reduced the manufacturing cost of eccentric stiffener, has increased the reliability of transmission.

Description of drawings

Be described in further detail below in conjunction with accompanying drawing and the preferred embodiments of the present invention.

Fig. 1 is the cutaway view of power tool transmission mechanism part of the present invention.

Fig. 2 is along the cutaway view of A-A line among Fig. 1.

Fig. 3 is the front view of the eccentric part in the power tool of the present invention.

The part schematic diagram of eccentric stiffener when Fig. 4 a does not rotate for the main shaft in the power tool of the present invention.

Fig. 4 b is along the cutaway view of B-B line among Fig. 4 a.

Fig. 5 a is the turn clockwise part schematic diagram of eccentric stiffener 90 ° time of the main shaft in the power tool of the present invention.

Fig. 5 b is along the cutaway view of C-C line among Fig. 5 a.

Fig. 6 a is the turn clockwise part schematic diagram of eccentric stiffener 180 ° time of the main shaft in the power tool of the present invention.

Fig. 6 b is the cutaway view of D-D line among Fig. 6 a.

Fig. 7 a is the turn clockwise part schematic diagram of eccentric stiffener 270 ° time of the main shaft in the power tool of the present invention.

Fig. 7 b is along the cutaway view of E-E line among Fig. 7 a.

Wherein, the related elements reference numeral is as follows:

1. casing 2. motors 3. main shafts

4. eccentric part 5. shift forks 6. driving shafts

7. working head 41. outer rings 42. inner rings

43. 51b. branch of rolling member 51a. branch

52. through hole 421. outlines 422. endoporus

The specific embodiment

With reference to Fig. 1, the present invention has disclosed a kind of power tool, especially a kind of power tool with eccentric drive mechanism.Power tool comprises casing 1, be positioned at the motor 2 of casing 1, the main shaft 3 by motor 2 drives is connected the eccentric part 4 on the main shaft 3, shift fork 5 that is connected with eccentric part 4 and the driving shaft 6 pivotally connected with shift fork 5, dismountable working head 7 that is equipped with on the driving shaft 6.One end of shift fork 5 is provided with the through hole 52 that connects driving shaft 6, and the other end forms a pair of 51a of branch, 51b makes eccentric part 4 just be stuck between a pair of 51a of branch, the 51b.

With reference to Fig. 2, main shaft 3 has rotation X, and driving shaft 6 has rotation Y, and the rotation Y of driving shaft 6 is perpendicular to the rotation X of main shaft 3, and the inner ring 42 of eccentric part 4 closely cooperates with the front end of main shaft 3 and rotates synchronously along with the rotation of main shaft 3.Outer ring 41 activities of one end of shift fork 5 and eccentric part 4 touch, and the other end and driving shaft 6 closely cooperate.

With reference to Fig. 3, eccentric part 4 comprise outer ring 41, inner ring 42 and be arranged on outer ring 41 and inner ring 42 between rolling member 43.Wherein outer ring 41 is common toroidal, the center of circle of outer ring 41 is O1, the center of eccentric part 4 is the center of circle O1 of outer ring 41, the center of the outline 421 of inner ring 42 and outer ring 41 are concentric also to be O1, the center of circle of the endoporus 422 of inner ring 42 is O2, the center of circle is that the O1 and the center of circle are that distance between the O2 is L, and promptly the endoporus 422 of inner ring 42 is with respect to eccentric part 4 eccentric settings, and the shape of outline 421 is a cam-like with respect to the center of circle O2 of endoporus 422.Rolling member 43 can be ball, roller or needle roller etc.

The transmission principle of power tool of the present invention is around axis Y rotation by motor 2 drive shaft 3 that are positioned at casing 1, close-fitting is connected eccentric part 4 on the main shaft 3 along with main shaft 3 rotation, the shift fork 5 that is connected with this eccentric part 4 be subjected to eccentric part 4 the motion of outer ring 41 radial cams drive and produce rotation around driving shaft 6 and move back and forth perpendicular to shift fork 5, perhaps be referred to as to rotate reciprocating vibration.Through the moment of torsion transmission of said elements, the driving shaft 6 of last power tool can produce rotation and move back and forth.After on this driving shaft 6 working head 7 being installed removably, this working head 7 will produce same rotation and move back and forth, and the track of its motion is shown in the arrow among Fig. 1.

To describe the eccentric gearing process of power tool of the present invention below in detail.

With reference to Fig. 4 a and Fig. 4 b, main shaft 3 does not begin around the axis X rotation, and at this moment, shift fork 5 is parallel with respect to axis X.With reference to Fig. 5 a and Fig. 5 b, main shaft 3 turns clockwise 90 °, the inner ring 42 of eccentric part 4 is also along with main shaft 3 turns clockwise 90 °, the outer ring 41 of eccentric part 4 is radial deflection under the drive of inner ring 42 outlines 421 cam surfaces, conflict in outer ring 41 and radial effect power makes shift fork 5 around axis Y rotation in one of them 51a of branch of shift fork 5, at this moment, shift fork 5 has certain included angle α with respect to axis X.With reference to Fig. 6 a and Fig. 6 b, main shaft 3 continues dextrorotation and goes to 180 °, the inner ring 42 of eccentric part 4 is also along with main shaft 3 turns clockwise 180 °, the direction of outer ring 41 radial deflections of eccentric part 4 is vertical with shift fork 5 travel directions at this moment, the outer ring 41 that is eccentric part 4 does not apply branch 51a, the 51b of active force in shift fork 5 on the direction of motion of shift fork 5, shift fork 5 is parallel with respect to axis X.With reference to Fig. 7 a and Fig. 7 b, main shaft 3 continues dextrorotation and goes to 270 °, the inner ring 42 of eccentric part 4 is also along with main shaft turns clockwise 270 °, the outer ring 41 of eccentric part 4 radial deflection under the drive of inner ring 42 outline cam surfaces, conflict in outer ring 41 and radial effect power makes shift fork 5 around axis Y rotation in the 51b of wherein another branch of shift fork 5, at this moment, shift fork 5 has certain included angle α with respect to axis X.Like this, the rotation that main shaft 3 does not stop, eccentric part 4 is along with main shaft 3 rotates synchronously, thereby the outer ring of eccentric part 4 41 radial deflection shift forks 5 move back and forth in the certain angle scope, shift fork 5 drives driving shaft 6 simultaneously and also moves back and forth in the certain angle scope, is installed in working head 7 on the driving shaft 6 also along with being rotated reciprocating motion.

Power tool provided by the present invention has avoided carrying out the processing of eccentric shaft, makes the handling ease of eccentric stiffener, has reduced the manufacturing cost of eccentric stiffener, has increased the reliability of transmission, helps the wide application in stand on industry.

Claims

1. power tool, comprise casing (1), be arranged on the motor (2) in the casing (1), main shaft (3) by motor (2) driving, and be connected eccentric drive mechanism on the main shaft (3), described eccentric drive mechanism comprises the eccentric part (4) that is connected on the main shaft (3), be connected the shift fork (5) on the eccentric part (4), described shift fork (5) moves back and forth by the rotation of the eccentric part (4) on the main shaft (3), the other end of described shift fork (5) is connected with driving shaft (6), described driving shaft (6) passes through shift fork (5) thereby the oscillating motion of motion driven tool head (7), it is characterized in that: described eccentric part (4) comprises outer ring (41), inner ring (42) and be arranged on outer ring (41) and inner ring (42) between rolling member (43), the endoporus (422) of the inner ring (42) of described eccentric part (4) is with respect to the eccentric setting of eccentric part (4).

2. power tool as claimed in claim 1 is characterized in that: described rolling member (43) can be ball, roller or needle roller.

3. power tool as claimed in claim 1, it is characterized in that: an end of described shift fork (5) is provided with the through hole (52) that connects driving shaft (6), the other end form a pair of branch (51a, 51b), described eccentric part (4) be stuck in a pair of branch (51a, 51b) between.