CN101331007A

CN101331007A - Vibration dampened hand-held power tool

Info

Publication number: CN101331007A
Application number: CNA2006800477372A
Authority: CN
Inventors: 埃里克·龙达尔
Original assignee: Dentatus AB
Current assignee: Dentatus AB
Priority date: 2005-12-20
Filing date: 2006-11-29
Publication date: 2008-12-24
Also published as: SE529430C2; SE529430C8; ATE543614T1; SE0502838L

Abstract

A hand-held power tool, e.g. a high speed file or polisher has a single rotary drive shaft (8) to which there is locked a first eccentric member (1) in which a second eccentric member (2) can be rotated and locked forming a first assembly (10). The second eccentric member has an eccentrically placed crank pin in the form of a hollow needle bearing ring (2a) through which the drive shaft passes. The outer ring (7) of the needle bearing reciprocally drives a connecting rod (1.2) to a tool holder (9). The drive shaft also passes through an identical assembly (10f) of first and second eccentric members (1', 2') disposed upside down on the first assembly (10) and reciprocally driving, in the opposite direction and in counterphase, a counterweight, to cancel the reactive oscillating forces from the tool holder during operation, which would otherwise have to be absorbed by the hand and aim of the operator. Relative rotational adjustment of the first (1, 1') and second (2, 2') eccentric members simply changes the length of stroke of the tool holder and the counterweight, respectively.

Description

Vibration dampened hand-held power tool

Technical field

The present invention relates to a kind of hand-hold power tool as described in the preamble as claimed in claim 1.

Background technology

Pneumatic, hydraulic pressure is applied to multiple different career field with electronic hand-hold power tool.The rotation of rotation drive motor is converted into the instrument that is used for the traverse motion for example sawing, file and polish usually can produces sizable vibration, and this vibration can be delivered on the arm of tool-user.

The long-term vibratory tool that uses not only can cause tendon, muscle, bone and joint to change, but also the system that can affect the nerves.More than these all effects be collectively referred to as vibrational arm syndrome (Hand-Arm Vibration Syndrome is abbreviated as HAVS).When hand is caught a cold, refer to that in vain the symptom of disease (VWF) can be aggravated.

Below be the common report that is subjected to the workman that the vibrational arm syndrome influences: one or more fingers can bleach (albefaction) when catching a cold, and point numb and lose one's senses; Refer in vain lose light touch, the pain sensation and creeping chill during the disease periodical attack, the forfeiture curable grip, and point in some cases and wrist place generation bone cyst.

Aggravate gradually gradually by development and symptom along with the time for the vibrational arm syndrome.Its symptom appear the time that may need several months even several years.Along with the confirmation of science, in the many decades, avoid the effort of these devastating effects more and more to come into one's own in the past to this late effect.

Except using antivibration gloves, limit exposure in the maximum duration of vibration and the sharper cutting element of use, the oscillation intensity that hand-hold power tool produced has also been carried out stricter requirement, this oscillation intensity frequency weighting acceleration (m/s ²) measure.Its peak of standard code that ACGIH (American Conference of Government Industrial Hygienists is abbreviated as ACGIH) is formulated is at 4m/s ²Under used 8 hours.The absolute upper limit of Europe official standard 2002/44/EC regulation then is 5m/s in 8 hours ²

For a period of time, the hand-hold power tool industry is being born very big pressure, because need develop a kind of instrument that can either reaction force can not passed to the arm of tool-user for the enough linear reciprocating power of operations such as saw, file generation again.

Swedish patent has been described the hand-hold power tool that a kind of rotation that motor is produced is converted into reciprocating type linear movement for No. 134791.Wherein offset assembly comprises first member and second member, and first member is fixedly mounted on the driving shaft and has with respect to the eccentric circular cavity that is provided with of driving shaft, and second member is coupled in the circular cavity of first member.In order to carry out linear reciprocal movement, tool holder is connected on the rod bearing of circular second member in the position with respect to the central axis off-centre of second member in a usual manner with connecting rod.By rotating circle second member in first member, thereby the degree of eccentricity of two members can addition provide range, perhaps second member in first member is rotated 180 ° from maximum travel position, thereby obtained a kind of structure, wherein the connecting-rod bearing is positioned at the rotation place of first member, is zero thereby make linear course.By rotating second member in first member, can realize until all haul distances of range.When configuring needed haul distance, just first member and the locking of second member can be one by the screwed in place screw.

Because first member and second member are made by same material, and the relative position of second member how to set that they all can form jointly with the rotation be the central circular unit, so this rotary unit itself is balance all the time.But the reaction force that linear reciprocal movement produced of instrument is not balanced, so that must be absorbed by user's arm.

In order to subdue the reaction force in the similar hand-held reciprocating power instrument, various baroque mechanisms have been proposed, as the saw of describing among the US20050022395Al.In this saw, the rotation of motor drives the linear reciprocal movement that crank-pin is converted into saw blade by rotary crank wheel and the eccentric saw blade that is arranged on the crankwheel.In order to balance vibration force, the rotary crank wheel is provided with another and drives the crank-pin that counterweight seesaws.As described in the specification of US20050022395A1, the weight of counterweight is fixed, and the standard resistance that produces when wearing standard material for saw, and the angle of revolution of counterweight swing permanently is set to the estimated value of standard.Need regulate the reciprocating motion of counterweight because eliminate the words of vibration, so the haul distance of saw blade can't be adjusted.

Therefore, the setting of this design is constant, can't carry out any adjusting to the motion of haul distance or counterweight.

Summary of the invention

Technical problem solved by the invention is a kind of hand-held reciprocating power instrument of structure, the mechanism that is used for work and vibration compensation of this power tool is solid, compact and simple, and this power tool can be under the situation of not damaging vibration elimination ability the haul distance of adjustment means easily.

This hand-held reciprocating power instrument is applicable to vibration at high speed and can bears long-term the use continuously and significantly do not reduce its vibration elimination ability.

The hand-held reciprocating power instrument of this disclosed feature of characteristic by having claim 1 is realized.

The more favourable embodiment according to the present invention, first and second offset assemblies are made up of identical part, produce and maintenance cost thereby reduce.

The more favourable embodiment of the present invention is disclosed in the dependent claims.

Description of drawings

Now with reference to the non-limiting preferred implementation shown in the accompanying drawing the present invention is described, in the accompanying drawing:

Fig. 1 illustrates the stereogram according to hand-held reciprocating power instrument of the present invention;

Fig. 2 illustrates the exploded view of power tool shown in Figure 1;

Fig. 3 is the exploded view of the part of first offset assembly; And

Fig. 4 (a) illustrates along the longitudinal sectional drawing of the central plane A-A of this power tool, and Fig. 4 (b) illustrates the end-view of described power tool.

The specific embodiment

Figure 1 shows that it comprises shell 21, columniform counterweight cover 22 and tool holder 9 according to hand-held reciprocating power instrument of the present invention, tool holder 9 is used for keeping securely file or polishing tool so that it moves reciprocatingly.In actual file finishing or polishing process, can utilize adjuster 23 to regulate its angle around the longitudinal axis of described instrument.Described instrument is connected to the flexible rotating shaft that motor drives by shaft coupling 24.

Fig. 2 shows the exploded view of described hand-held reciprocating power instrument, there is shown the rotating shaft 8 that is fixed with first offset assembly 10 (undecomposed among the figure) and second offset assembly 10 ' (decomposing) on it, first offset assembly 10 is used for linear reciprocal movement is passed to tool holder 9, the second offset assemblies 10 ' be used for linear reciprocal movement is passed to counterweight 6.First offset assembly 10 and second offset assembly 10 ' form (simultaneously referring to Fig. 3 and Fig. 4) by identical part: have respectively the circular distal member 1,1 of centre bore 1c, 1c ' ', rotating shaft 8 passes centre bore 1c, 1c '.Each circular distal member all locks by lock nut 5,5 ' securely rotations with respect to rotating shaft 8.Each distal member 1,1 ' all is circular and is the center with rotating shaft 8, but each distal member 1,1 ' inside are provided with respect to rotating shaft 8 eccentric cannelure 1b, the 1b ' that are provided with.Cylindrical shape part 2b, the 2b ' of nearside member are coupled in the described cannelure.The opposite side of described nearside member is provided with needle bearing

ring

2a, 2a ', and described needle bearing

ring

2a, 2a ' are provided with prejudicially with respect to the cylindrical shape part 2b of this nearside member, the center of 2b '.Ring 7,7 ' be needle bearing 4,4 ' outer shroud and have attachment arrangement, described attachment arrangement be used to lead be connected to tool holder 9 or counterweight 6 in case transmit reciprocating connecting rod 12,12 '.

Two offset assemblies 10,10 ' be placed upside down toward each other, and same rotating shaft 8 passes them, thus form very solid, simple structure.Described nearside (second) member (2,2 ') is adjacent one another are, thereby reduces the reaction couple of their the two generations to the full extent.Because two offset assemblies are made by identical parts, make to be easy between them balance each other, and have saved manufacturing cost and replacement part.

From Fig. 4 (a), can be clear that, by unscrewing screw rod 3 and in the groove of distal member, rotating the nearside member, the degree of eccentricity of cannelure 1b, 1b ' and needle bearing

ring

2a, 2a ' can be compound gradually and finally form connecting rod 12,12 ' maximum length of stroke, or subdue each other and form almost nil haul distance so that the final degree of eccentricity is offset each other fully.

Nearside member 2,2 ' the edge on numbering

scale

2d, 2d ' be used for determining that stroke is from the zero composite eccentric degree to maximum 5mm.The user can be easily is just in time identical with the stroke of tool holder with the travel settings of counterweight.This can easily check by removing lid 25.

Claims

1. produce reciprocating hand-hold power tool, comprising:

Reciprocating tool holder (9);

Rotating shaft (8);

First offset assembly (10 '), it is fixed to the reciprocating type linear movement that described tool holder (9) was gone up and the rotation of described rotating shaft was converted into to described rotating shaft (8);

Counterweight (6), it offsets the reaction force that described tool holder produces,

It is characterized in that:

Be fixed to second offset assembly (10) on the described rotating shaft (8) equally, described second offset assembly (10) is converted into the reciprocating type linear movement of described counterweight (6) with the rotation of described rotating shaft, and the reciprocating type linear movement of the reciprocating type linear movement of described counterweight (6) and described tool holder (9) is opposite and phase place is identical on diametric(al);

In described first and second offset assemblies (10 ', 10) each comprises first member (1,1 ') and second member (2,2 '), described first member (1,1 ') is fixedly mounted on the described driving shaft (8) and has the circular portion (1a, 1a ') eccentric with respect to described driving shaft (8), described second member (2,2 ') can be regulated and can be with respect to described circular portion (1a, 1a ') locking with rotary way, and described second member (2,2 ') has transmit the eccentric crank pin of reciprocating type linear movement when described driving shaft rotation.

2. hand-hold power tool according to claim 1 is characterized in that, described eccentric crank pin is the cylindrical bearing axle journal (2a, 2a ') of hollow, and described driving shaft (8) passes from described bearing journal (2a, 2a ') inside.

3. hand-hold power tool according to claim 2 is characterized in that, described first and second offset assemblies (10 ', 10) comprise identical part.

4. according to claim 2 or 3 described hand-hold power tools, it is characterized in that, described second offset assembly (10) is relative with described first offset assembly (10 ') to be installed reversedly, and described second member (2,2 ') is close to each other, and described first member (1,1 ') away from each other.

5. hand-hold power tool according to claim 1 is characterized in that, described counterweight is installed on the connecting rod (12 ') that is driven by the crank-pin of described second offset assembly (10 '), and described counterweight can change so that the different instrument of balance.

6. hand-hold power tool according to claim 2, it is characterized in that, the cylindrical bearing axle journal of described hollow is the interior ring of needle bearing, and the outer shroud of described needle bearing (7,7 ') is connected to connecting rod (12,12 ') so that realize described tool holder (9) respectively or the reciprocating motion of described counterweight (6).

7. hand-hold power tool according to claim 2, it is characterized in that, each offset assembly is provided with circumferential scale (2d), and described first member of described circumferential scale (2d) indication is with respect to the exact position of described second member and therefore indicate reciprocating haul distance.

8. hand-hold power tool according to claim 7 is characterized in that, described haul distance can be regulated between 0 to 5mm.

9. according to any described hand-hold power tool in the aforementioned claim, it is characterized in that described power tool is high speed file or polisher.