JP4338469B2 - Portable work machine - Google Patents

Description

  The present invention relates to various portable work machines such as a brush cutter, a pruning machine, a high branch pruning machine, and a chain saw, and more particularly to a portable work machine that can exhibit an optimum vibration damping function regardless of increase or decrease in engine speed.

  Conventionally, various portable work machines such as a brush cutter, a pruning machine, a high branch pruning machine, and a chain saw have been frequently used. As a portable work machine of this type (for example, see Patent Document 1), a drive shaft rotatably supported in a long main pipe (guide tube) is driven and rotated via a centrifugal clutch of an engine. A brush cutter that drives a work tool such as a cutter blade by a drive shaft is disclosed. A handle support case (accommodating cage) is disposed around a part of the outer periphery of the main pipe of the brush cutter, and an operation handle is supported and fixed to the handle support case via a handle support bracket.

  Both end portions in the longitudinal direction of the handle support case accommodate and support a pair of upper and lower vibration isolating rubbers having a substantially rectangular cylindrical shape, and one end portion thereof is coupled to the clutch cover of the centrifugal clutch via the vibration isolating rubber. Has been. On the other hand, the other end of the handle support case in the longitudinal direction is connected to a case support cover that is externally fitted and fixed to the main pipe via the anti-vibration rubber.

  The anti-vibration rubber has a radial asymmetric shape, and is directed toward the radial direction of the cylindrical core portion and the core portion that are inserted and supported by mounting pins protruding from the clutch cover and the case support cover, respectively. It consists of a pair of tubular extending portions on both sides that extend in opposite directions. The length of the handle support case in the X-axis direction that extends perpendicularly in the left-right direction with respect to the Z-axis in the longitudinal direction is longer than the length in the Y-axis direction that extends perpendicularly in the vertical direction with respect to the Z-axis in the longitudinal direction. Is set.

In this conventional brush cutter, an excellent vibration damping function is ensured with respect to vibration generated by the core portion across the mounting pin. The extension portion is provided with a hollow space, and when an impact force acts on the extension portion when a work tool hits an obstacle or the like, the inner surface of the hollow space has a direction of a force acting on the impact. Compressed and in contact with each other, the extension ensures that the impact is guided. By setting the hollow space in a different form and size and forming the hollow space in the extended portion, a desired vibration damping effect by the vibration-proof rubber is obtained.
German Patent Application No. 19502171

  By the way, when performing work using a portable work machine such as a brush cutter, the work contents and work conditions being carried out under various environments such as change of work range and presence or absence of obstacles, or In general, it is performed at an optimum engine speed according to the skill of the worker.

  The anti-vibration rubber structure disclosed in Patent Document 1 is for absorbing and removing relatively small external force, vibration, and the like. Small vibration generated during low-speed operation of the engine, small transmitted from the outside. It can absorb and suppress impacts. However, even if the above-described anti-vibration rubber structure is used, it is difficult to absorb large vibrations generated during high-speed operation of the engine and suppress transmission to the working machine only by the presence of the anti-vibration rubber. It has become.

  For this reason, during high-speed operation of the engine, the reaction applied to the worker is extremely large, and physical fatigue tends to overlap, and the hand, arm, etc. are likely to suffer from diseases such as inflammation due to long-term use. The anti-vibration rubber structure disclosed in Patent Document 1 is not suitable as a vibration absorbing structure for high-speed engine operation. As a result, work must be performed within a range where the engine speed is reduced with little vibration from the engine or / and the cutter blade, etc., and work efficiency and the like are likely to be reduced.

  The present invention has been made to solve the above-described conventional problems, and its specific purpose is to enable a desired structure to have a vibration damping function with a simple structure, and to change work contents and work conditions. Accordingly, an object of the present invention is to provide a portable work machine capable of rationally reducing vibration generated during engine operation and improving work efficiency and the like.

The invention according to claim 1 includes a work tool, a drive device connected to the work tool in a drivable manner, a gripping device disposed between the work tool and the drive device, the drive device, and the gripping device. A damping member interposed between the working tool and the driving device, and one end rotatably connected to the driving device to support the insertion of the pipe. A drive shaft that drives and rotates the work tool, and a cylindrical handle support case supported by the main pipe and the drive device via the vibration damping member, and the gripping device is attached to the handle support case. A portable work machine that is directly supported , wherein the vibration damping member includes a vibration-proof coil spring that is supported at one end by either one of the drive device or the gripping device and at the other end by a free end. From the free end of the anti-vibration coil spring It is closely fitted into yl spring, the driving device and the gripping device Ri name and a one rubber vibration isolator which other one end is supported with the damping member of the drive device side, first to It consists of a third damping member, and the first and second damping members are arranged on the same circumference of the upper semicircle centered on the drive shaft with a phase difference of a predetermined angle on the left and right objects. The third damping member is different from the first and second damping members on the bisector between the centers of the first and second damping members and across the drive shaft. The portable work machine is characterized in that it is arranged on the circumference of a lower semicircle having a diameter, and the diameter of the upper semicircle is larger than the diameter of the lower semicircle .

  The invention according to a second aspect is the invention according to the first aspect, wherein the anti-vibration rubber has a hollow cylindrical portion, and the anti-vibration rubber is arranged on either one of the driving device and the gripping device. It is characterized in that it is supported by a mounting pin inserted into the hollow cylinder portion.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein one or more of the anti-vibration rubber around the hollow cylindrical portion is parallel to the center line and open at both ends. It is characterized by having a cavity. The hollow portion is preferably arranged with a phase difference of a predetermined angle on the same circumference around the central axis of the cylindrical portion, as in the invention according to claim 4. As described above, it is more desirable to have the same size.

  The invention according to claim 6 is the invention according to any one of claims 3 to 5, wherein the cavity has a wing-shaped cross section, adjacent cavities are separated from each other, and a part thereof Is characterized in that they are arranged so as to overlap in the radial direction.

Further, the invention according to claim 7 is the invention according to claim 1, wherein the portable work machine is disposed between the casing of the drive device and the grip for operating the work machine fixed to the casing. It is a chain saw that is provided with a vibration damping member.

  The invention according to claim 1 includes various portable manual working machines such as a brush cutter, a pruning machine, a high branch pruning machine, and a chain saw. Generally, the portable work machine is operated by operating and manipulating a gripping device disposed between a work tool and a drive device. At this time, extremely large vibrations from the work tool and / or the drive device act on the gripping device from various directions and are transmitted to the hand, arm, etc. of the operator. Therefore, the vibration applied to the worker becomes extremely large.

  In the present invention, one end of an anti-vibration coil spring is supported by one of the driving device and the gripping device, and one end of the anti-vibration rubber is provided by either the driving device or the gripping device. Is supported on the same straight line as the anti-vibration coil spring, and the other end of the anti-vibration rubber is closely fitted to the free end of the anti-vibration coil spring so as not to be relatively rotatable. With this configuration, it is possible to ensure vibration damping performance of the vibration-proof coil spring during high-speed engine rotation. In addition, the vibration-proof rubber can be imparted with vibration damping properties during low-speed rotation of the engine, and prevent the reaction to the worker due to intermittent impact of the work tool during operation and vibration of the drive device during operation. be able to.

  As the damping member, an optimum damping function can be obtained by appropriately setting the hardness of the damping rubber, the spring characteristics of the damping coil spring, and the like. By constituting a composite structure in which both the vibration-proof coil spring and the vibration-proof rubber are combined in series, a combined action that can be achieved by both the vibration-proof coil spring and the vibration-proof rubber can be drawn out. As a result, even in various environments such as changes in the work range and presence / absence of obstacles, the operability of the optimal work machine according to the work contents and work conditions being performed, the worker's skill, etc. Maneuverability can be realized between the maximum engine speed and the minimum engine speed. In addition, worker fatigue can be reduced, and work efficiency and the like are significantly improved.

  The invention according to claim 2 is collinear with a vibration-proof coil spring that is vertically supported so as not to rotate relative to any one of the driving device and the gripping device, and includes the driving device and the gripping device. The hollow cylinder portion of the anti-vibration rubber is inserted and supported so as not to rotate relative to a mounting pin arranged perpendicularly to either one of the two.

  According to the above configuration, the hollow cylinder portion of the vibration-proof rubber can be easily inserted and supported on the mounting pin, and the free end of the vibration-proof coil spring and the other end of the vibration-proof rubber can be coupled. However, it is easily and stably coupled with a small number of members. Thus, no special fixing means is required, and the free end of the anti-vibration coil spring can be positioned and coupled to the other end of the anti-vibration rubber with a simple structure. In addition, the assemblability and handling at the time of manufacturing and maintenance inspection of a work machine having a vibration control function can be sufficiently enhanced.

  In the inventions according to claims 3 to 5, elasticity is imparted to all directions by forming a hollow portion extending inside the vibration-proof rubber. A cavity is formed in the anti-vibration rubber to facilitate elastic deformation, thereby improving the vibration damping function. Even if a large external force acts on the work machine from various directions, the presence of the hollow portion can ensure the flexibility of the anti-vibration rubber, and the reaction force applied to the worker due to the vibration of the work machine generated during work can be reduced. It will be possible to suppress. The degree of elasticity of the anti-vibration rubber can be changed by adjusting the size, form, number of arrangement, installation position, and the like of the cavity.

  According to the sixth aspect of the present invention, at the time of work, while maintaining the elasticity of the anti-vibration rubber, it is possible to ensure rigidity and moderately increase the strength. With the above-described configuration, the anti-vibration rubber can absorb the expansion and contraction operation of the anti-vibration coil spring by its elasticity. Moreover, the free end of the anti-vibration coil spring can be stably and securely held at the end of the anti-vibration rubber, and the mounting strength between the anti-vibration coil spring and the anti-vibration rubber can be increased moderately. The required form can be maintained and the sustainability of the damping characteristics can be ensured even by a large external force acting from various directions.

Here, in the invention according to claim 1 , the vibration damping member can be effectively used in a brush cutter which is a typical form of a portable work machine . The handle support case can be indirectly supported with a required gap with respect to the main pipe and the drive device via the vibration damping member. In addition, the gripping device can be directly supported by the handle support case.

  By indirectly supporting the gripping device on the main pipe and the driving device in combination with the required gap, reaction to the operator due to vibration of the working machine during the mowing operation is suppressed. With the above configuration, the vibration from the cutter blade and / or the driving device is effectively reduced with respect to the gripping device regardless of the increase or decrease of the engine speed. For this reason, it is possible to stably perform the mowing work with the optimum operability and maneuverability of the brush cutter according to the work contents, work conditions, and the like.

In the invention according to yet claim 1, also defines layout number and installation position of the damping member. During the operation of the portable work machine, it is necessary to give the vibration damping member necessary elasticity and to appropriately increase the strength of the vibration damping member. By providing the above-described configuration, it is possible to maintain the required form and ensure the damping performance against a large external force acting from all directions such as front and rear, top and bottom, and left and right. The number of installed damping members, the installation position, and the like can be set based on the relationship with other factors such as the installation position of a member that generates vibration in the engine.

In the invention according to claim 7 , since the damping member can be easily assembled with few members as described above, the damping member can be applied to various portable manual work machines in addition to the brush cutter. The vibration member can be easily arranged. Even in a chain saw that is one of manual work machines, a component that generates vibration and the handgrip can be arranged with a required gap so as not to directly contact each other.

  At this time, due to the presence of the damping member coupled with the gap formed between the vibration generating member and the hand grip, it is ensured that the vibration of the hand grip is attenuated, without fatigue the operator for a long time, It becomes possible to operate and steer the chainsaw stably and accurately.

Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings.
FIG. 1 is an external perspective view of a brush cutter according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of a main part showing the engine portion side of the brush cutter, and FIG. 3 is an operation handle portion of the brush cutter. FIG. 4 is a sectional view taken along line IV-IV in FIG. 2. In the present embodiment, a brush cutter will be described as an example of the portable work machine. However, the present invention is not limited to this, and various portable devices such as a pruning machine, a high branch pruning machine, and a chain saw are available. It can be applied to various manual work machines.

  In FIG. 1, reference numeral 1 indicates a trimming machine including an engine 3 that drives and rotates a cutter blade 2. As shown in FIG. 2, a fan 5 and a centrifugal clutch 6 are fixed to the crankshaft 4 of the engine 3 in series. A fan cover 7 including the fan 5 is fixed to an engine cover 12, and a clutch housing 11 that rotatably supports a cylindrical output shaft 9 of a clutch drum 8 including the centrifugal clutch 6 via 10. It is fixed to the engine cover 12.

  A rear end portion of the long circular tubular main pipe 13 is inserted and fixed in the front end cylindrical portion of the clutch housing 11. As shown in FIG. 3, a drive shaft 15 is rotatably supported inside the main pipe 13 via a plurality of bearings 14,..., And the rear end portion of the drive shaft 15 is connected to the clutch. It is inserted into the cylindrical output shaft 9 of the drum 8 and is splined. As shown in FIG. 1, a gear case 16 that rotatably supports and fixes the cutter blade 2 is connected and fixed to the distal end portion of the main pipe 13, and the distal end portion of the drive shaft 15 is built in the gear case 16. It is rotatably connected to a reduction gear (not shown).

  The main pipe 13 is provided with a gripping device 20 via a handle support case 17 extending from the engine side to the operation handle side. The gripping device 20 includes a handle support bracket 21 that is fastened and fixed to an opposing surface of the handle support case 17 on the operator side, and a substantially U-shaped operation handle 22 that is fastened and fixed to the handle support bracket 21. have.

  The outer shape of the handle support case 17 is made of a synthetic resin having a substantially polygonal cross section and a long and narrow molded product. As shown in FIGS. 2 and 3, the handle support case 17 has housing space portions 17a that are open at both end surfaces in the length direction, and a part of the outer periphery of the main pipe 13 is located in the housing space portion 17a. Is surrounded by the required interval.

  The handle support case 17 has a curved surface curved in an arc shape inward at the cross section of the insertion opening on the engine side and the operation handle side, and the curvature radius of the curved surface is different. The insertion opening on the engine side of the handle support case 17 is elastically supported by an annular case support plate 18 connected to the clutch housing 11 as shown in FIGS. As shown in FIG. 3, the insertion opening on the operation handle side of one handle support case 17 is elastically supported by an annular case support cover 19 that is fastened and fixed to the outer periphery of the main pipe 13.

  As shown in FIG. 4, damping members 30 and 31 are disposed between the clutch housing 11 and the case support plate 18, and between the handle support case 17 and the case support cover 19. A member 31 is disposed. Due to the presence of these damping members, vibrations and impacts of the cutter blade 2, engine 3 and main pipe 13 during operation are reduced, so that they do not directly act on the operation handle 22.

  The trimming machine 1 configured as described above has no difference in the basic configuration from the conventional one except for the configuration of the damping member. The main object of the present invention is to prevent a reaction to the worker due to vibrations of the cutter blade 2, the engine 3, and the main pipe 13 that are generated when the engine is operating or trimming regardless of the rotational speed of the engine 3. Yes.

  The main feature of the present invention is that the vibration damping member has a composite structure in which both the vibration-proof coil spring 30 and the vibration-proof rubber 31 are combined in series, and one of the engine portion side and the operation handle portion side is provided. One end of the vibration-proof coil spring 30 is supported by a member, and one end of the vibration-proof rubber 31 is placed on the same straight line as the vibration-proof coil spring 30 on the other member of the engine portion side and the operation handle portion side. I support it. In addition, the free end of the anti-vibration coil spring 30 and the other end of the anti-vibration rubber 31 are closely fitted so as not to rotate relative to each other. As a result, the vibration damping coil spring 30 can be secured with vibration damping performance during the high speed rotation of the engine 3, and the vibration damping rubber 31 can be imparted with vibration damping performance during the low speed rotation of the engine 3.

  FIG. 5 is a side view of an essential part showing an example of a mounting structure of a damping member attached to the clutch housing of the engine, FIG. 6 is a sectional view taken along line VI-VI in FIG. 2, and FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 7, FIG. 9 is a front view showing an example of a vibration-proof coil spring in a state in which a vibration-proof rubber is tightly fitted, and FIG. XX line arrow sectional drawing, FIG. 11 is a side view of the vibration isolator rubber.

  As a suitable example in which the vibration-proof coil spring 30 and the vibration-proof rubber 31 are arranged in the clutch housing 11 on the engine part side, it is shown in FIGS. That is, on the operation handle side facing surface of the clutch housing 11, three first to third mounting pins 11a to 11c for inserting and supporting the anti-vibration rubber 31 are projected. These mounting pins 11a to 11c have the same size, but the first and second mounting pins 11a and 11b are made of a cylindrical body, and the third mounting pin 11c is made of a cylindrical body.

  As shown in FIG. 6, the first and second mounting pins 11a and 11b are arranged at a predetermined angle with respect to the left and right objects on the same circumference of the upper semicircle centered on the cylindrical output shaft 9 of the clutch drum 8. It is arranged with a phase difference of. The third mounting pin 11c is directly below the cylindrical output shaft 9 on a bisector between the centers of the first and second mounting pins 11a and 11b, and the first and second mounting pins 11a and 11b. It is arranged on the circumference of the lower semicircle with a different diameter on the opposite side. The first and second mounting pins 11a and 11b are closer to the engine side than the third mounting pin 11c, and the upper semicircle has a larger diameter than the lower semicircle.

  By providing the above configuration, it is possible to maintain the required form of the vibration-proof rubber 31 and ensure the vibration-damping performance even with a large external force acting from all directions such as front and rear, top and bottom, and left and right. The form, size, arrangement number, installation position, and the like of each of the mounting pins 11a to 11c can be appropriately set in relation to other factors such as the installation position of a member that generates vibration in the engine.

  The three first to third anti-vibration rubbers 31 which are inserted and supported by the mounting pins 11a to 11c, respectively, have the same size and the same structure. As shown in FIGS. 7 and 8, the vibration isolating rubber 31 has eight hollow portions 31a,... Open at both ends around the hollow cylindrical portion of the vibration isolating rubber 31 having an annular flange on the outer peripheral edge. 31a. Each hollow portion 31a extends in parallel along the center line of the hollow cylindrical portion. Each cavity 31a is arranged with a phase difference of 45 ° on the same circumference centered on the center line of the hollow cylinder.

  The hollow portions 31a are not limited to be arranged with a phase difference of 45 °, and can be arranged with an appropriate phase angle difference. In this case, it is desirable to arrange the hollow portions 31a at equal intervals.

  By forming the hollow portion 31a, it becomes easy to be elastically deformed in all directions, and the vibration damping function can be improved against vibrations and impacts from each direction. Further, due to the presence of each hollow portion 31a, even if a large external force is applied to the brush cutter 1 from various directions, the vibration-proof rubber 31 is ensured to be flexible and work by vibration of the engine 3 generated during the brush cutting operation. Reaction to the person can be kept low.

  Further, according to the illustrated example, the cavity 31a has a wing-like cross section, adjacent cavities are separated from each other, and a part of them is overlapped in the radial direction. With this configuration, rigidity and strength are ensured while maintaining the elasticity of the vibration-proof rubber 31. The elastic motion of the anti-vibration coil 31 absorbs the expansion and contraction of the anti-vibration coil spring 30, and the free end of the anti-vibration coil spring 30 is stably and securely held at the end of the anti-vibration rubber 31. The mounting strength between the vibration-proof coil spring 30 and the vibration-proof rubber 31 is moderately increased, and the required form can be maintained and the vibration damping performance can be ensured even by a large external force acting from various directions.

  An optimal vibration damping function can be obtained by appropriately setting the hardness of the vibration-proof rubber 31. The degree of elasticity of the anti-vibration rubber 31 can be changed by adjusting the form, size, number of arrangement, installation position, and the like of the hollow portion 31a. The anti-vibration rubber 31 is not limited to the illustrated example, and instead of the hollow cylindrical portions opened at both end faces of the anti-vibration rubber 31, a circular cross section extends from both end faces of the anti-vibration rubber 31 to a substantially central portion. A blind hole-shaped cylindrical part centering on the center line of the part may be formed, and the hollow part 31a may also be formed in the longitudinal direction in a blind hole shape.

  The cavity 31a needs to be provided with some flexibility, particularly when the material of the vibration-proof rubber 31 is a hard resin such as a hard elastomer resin or various hard rubbers. By forming, the required flexibility is ensured. The degree of flexibility at this time can be adjusted by changing the hole diameter of the cavity 31a, the number of the cavity 31a installed, and the partition wall.

  On the other hand, three first to third cylindrical anti-vibration coil springs 30 are fixed to the periphery of the case support plate 18 for the convenience of the installation intervals of the mounting pins 11a to 11c. As the anti-vibration coil spring 30, spring elasticity of a compression coil spring is used. Each vibration-proof coil spring 30 has the same size and the same structure. As shown in FIGS. 9 to 11, the base end portion of the vibration-proof coil spring 30 opposite to the free end linearly extends outward along a part of the spring turning portion and bends in the radial direction. A substantially U-shaped end portion, and the end portion is a leg portion arranged in parallel to the case support plate 18, and is suitable for the peripheral portion of the case support plate 18. It is supported by fixing means.

  As a means for adhering the anti-vibration coil spring 30, for example, a structure in which a substantially U-shaped end portion of the spring turning portion is fastened and fixed to the support surface of the case support plate 18 with a mounting bolt, and the case support plate 18 is protruded. Various structures such as a cylindrical pin having an external thread provided or a structure in which a part of the spring turning portion is screwed and fixed to a cylindrical pin having an internal thread can be used.

  In attaching the vibration damping member, the hollow cylindrical portion of the vibration-proof rubber 31 can be easily inserted into and supported by the attachment pins 11a to 11c. In addition, the free end of the anti-vibration coil spring 31 and the other end of the anti-vibration rubber 31 can be easily and stably secured with a small number of members with a simple structure without requiring any special fixing means. It can be carried out. Therefore, it is possible to improve the assemblability and handling at the time of manufacturing and maintenance inspection of the brush cutter 1 having a vibration damping function.

  The anti-vibration rubber 31 is fitted and supported on each of the mounting pins 11a to 11c so that the anti-vibration rubber 31 is relatively non-rotatable. Fitted. Thus, a composite type damping member in which the vibration-proof coil spring 30 and the vibration-proof rubber 31 are arranged in series is obtained.

  By providing this configuration, the required shape of the vibration-proof coil spring 30 can be maintained in combination with the vibration-proof rubber 31 even with a large external force due to vibration or impact acting from all directions, and good vibration-damping performance can be obtained. Can be secured. Optimum according to the work contents and work conditions being carried out even under various environments such as change of work range and presence / absence of obstacles by the combined action of the vibration-proof coil spring 30 and the vibration-proof rubber 31 The operability and maneuverability of the brush cutter 1 can be ensured, and the maneuverability and operability can be ensured between the maximum engine speed and the minimum engine speed. Etc. can be remarkably improved.

  As shown in FIGS. 2 and 4, a plurality of plate-like contact ribs 17 b that are in contact with and in close contact with a part of the case support plate 18 are formed on the inner surface of the insertion opening of the accommodation space 17 a of the handle support case 17. .., 17b are extended in parallel along the center line of the drive shaft 15. When the handle support case 17 is overlaid and supported on the case support plate 18, the contact rib 17 b is in contact with and in close contact with a part of the case support plate 18, and the handle support case 17 is inserted. The open end is arranged between the engine cover 12 and a required gap.

  As a result, the handle support case 17 is elastically supported by both the anti-vibration coil spring 30 and the anti-vibration rubber 31 in a state of being constantly biased toward the opposite side to the engine side. The handle support case 17 has an appearance that is integrated with the modeling line of the engine cover 12, and the commercial value of the brush cutter 1 can be sufficiently increased.

  The form, wire diameter, number of installations, mounting structure, arrangement position, and the like of the anti-vibration coil spring 30 with respect to the case support plate 18 are not particularly limited as long as the case support plate 18 can be held by the anti-vibration coil spring 30. It is not something. As a form of the anti-vibration coil spring 30, instead of the cylindrical anti-vibration coil spring 30 wound at an equal pitch as in the illustrated example, for example, it may have two or more different spring constants in the compression direction. .

  Specifically, for example, two or more compression coil springs having different spring constants are arranged in multiple stages in series, or a single compression coil spring in which the coil diameter and wire diameter are changed in the middle, the wire diameter is constant. Non-linear springs such as cones and barrels that change the coil diameter in the middle can be used. In this way, optimal vibration damping and shape retention can be obtained by appropriately setting the spring characteristics of the vibration-proof coil spring 30 and the like.

  FIGS. 12-14 has shown an example of the attachment structure of the operation handle part. 12 is an exploded side view of the operation handle portion, FIG. 13 is a sectional view taken along line XIII-XIII in FIG. 3, and FIG. 14 is an enlarged sectional view taken along line XIV-XIV in FIG. In these drawings, substantially the same members as those in the embodiment of the vibration damping member on the engine side are denoted by the same member names and reference numerals, and are not described.

  In these figures, between the handle support case 17 and the case support cover 19, only the anti-vibration rubber 31 that does not have a flange except the anti-vibration coil spring 30 is disposed. Two cylindrical mounting pins 11 a and 11 b projecting from the case support cover 19 are provided for convenience, and the first and second mounting pins 11 a and 11 b are perpendicular to the central axis of the drive shaft 15. Are arranged on the same circumference with a phase difference of 180 ° in the circumferential direction.

  The lower second mounting pin 11b is arranged closer to the engine side than the upper first mounting pin 11a. As shown in FIG. 3, annular ribs 11a-1 and 11b-1 projecting from the periphery of the hollow cylinder portion of the vibration isolating rubber 31 are provided on the periphery of the mounting pins 11a and 11b of the case support cover 19. Has been.

  At the opening end of the handle support case 17 on the handle side, a rubber accommodating support case 17c is fixed by fastening bolts 17d so as to face the case support cover 19. The case 17c is formed with an annular recess 17c-1 that accommodates and supports the ends of the vibration isolating rubber 31 corresponding to the mounting pins 11a and 11b. On each of the mounting pins 11a and 11b, a hollow cylindrical portion of the anti-vibration rubber 31 is externally supported in parallel with the main pipe 13 with a predetermined interval.

  The handle support case 17 is elastically supported by the case support cover 19 via the anti-vibration rubber 31 as shown in FIGS. Thereby, vibrations acting on the main pipe 13 from the engine side or the cutter blade side are absorbed by the vibration isolating rubber 31.

  As shown in FIGS. 3 and 12, the handle support bracket 21 has a pair of upper and lower handle holding members 23, 24 and a handle engaging / disengaging member 25. Each handle clamping member 23, 24 is a shell having a plurality of vertical ribs therein, and main body parts 23 a, 24 a extending along the main pipe 13 and clamping parts 23 b, 24 b extending in a direction intersecting the main pipe 13. And has a substantially T-shape.

  As shown in FIG. 3, the handle engagement / disengagement member 25 is a long bolt 26 that is rotated by a manual rotation operation to engage / disengage the handle support bracket 21 and the operation handle 22. Yes. The handle engaging / disengaging member 25 is configured such that the handle support bracket 21 and the operation handle 22 can be engaged / disengaged by manually rotating the long bolt 26.

  In the main body portions 23a, 24a of the handle engaging / disengaging members 23, 24, insertion holes for the long bolts 26 are formed penetrating vertically. Between the opposing surfaces of the gripping portions 23b, 24b of the handle engaging / disengaging members 23, 24, recesses having semicircular arc surfaces for closely fitting the upper half portion and the lower half portion of the operation handle 22 are formed.

  As shown in FIG. 3, the handle engagement / disengagement member 23 has a cylindrical engagement portion 25a having a support surface for fixing and supporting the head of a long bolt 26 having an external thread at one end of the shaft portion. And through an insertion hole formed so as to penetrate up and down the main body portions 23a and 24a of the handle clamping members 23 and 24, and externally screwed into an insert nut 27 embedded and integrated in a part of the handle support case 17. It is supported so as to be rotatable between the screws.

  As described above, the handle support case 17 is elastically supported by the anti-vibration rubber 31 via the rubber housing support case 17c, and the operation handle 22 is not in direct contact with the main pipe 13 without being in direct contact with the main pipe 13. It is supported and fixed via both the handle support case 17 and the handle support bracket 21.

  For this reason, the vibration acting on the main pipe 13 from the engine side or the cutter blade side is absorbed by the vibration isolating rubber 31, and at the same time, the vibration to the handle support bracket 21 and the operation handle 22 is reduced due to the presence of the handle support case 17. Is done.

  In the illustrated example, a vibration damping structure in which only the vibration-proof rubber 31 is disposed between the case support cover 19 and the handle support case 17 without the vibration-proof coil spring 30 will be described. However, the present invention is not limited to the illustrated example.

  As an example of the vibration damping structure between the case support cover 19 and the handle support case 17, as in the vibration damping structure between the clutch housing 11 and the handle support case 17, Use a structure in which one end is supported by either the case support cover 19 or the handle support case 17 and the anti-vibration rubber 31 is closely fitted to the free end of the anti-vibration coil spring 31 so as not to relatively rotate. Of course you can.

  In this case, as an attachment structure of the vibration-proof coil spring 30, for example, an inner screw is formed in the annular recess 17c-1 of the rubber housing support case 17c, and the spring turning portion of the vibration-proof coil spring 30 is formed on the inner screw. It is only necessary to screw and fix a part of the structure, and various structures can be used.

  In this way, the handle support case 17 is indirectly supported with a required gap through the composite damping member composed of the vibration-proof coil spring 30 and the vibration-proof rubber 31 with the required gap, and the gap The operation handle 22 is indirectly supported by the engine 3 and the main pipe 13 in combination with the operation handle 22 to suppress the reaction to the operator due to the vibration of the brush cutter 1 that occurs during the brush cutting operation.

  As a result, the vibration of the operation handle 22 is reduced regardless of the increase or decrease of the engine speed, and the brush cutting is performed while maintaining the optimum operability and maneuverability of the brush cutter 1 according to the work contents and work conditions being performed. Work can be performed stably.

  FIG. 15 shows a schematic configuration of a chainsaw that is a second embodiment of the portable manual work machine. In the present invention, the damping member is composed of a small number of members and can be easily assembled. Therefore, even in the case of a chain saw in addition to the brush cutter 1, the mounting as shown in FIG. The damping member can be easily arranged with a structure. Therefore, detailed description of the vibration damping member and its mounting structure is omitted.

  In the figure, an engine (not shown) is provided at the center of a casing 41 of the chainsaw 40. A crankshaft (not shown) of the engine is connected to a driving means (not shown) of the bladed chain 42 via a centrifugal clutch (not shown). An upper grip 43 is attached to the upper surface 41a and the rear end surface 41b of the casing 41. One end of a front grip 44 is connected to the tip of the upper grip 43, and the other end is connected to the casing 41. Is connected to the lower surface 41c.

  In the second embodiment, as one of the characteristic parts of the vibration damping structure, a composite structure of a vibration-proof coil spring and a vibration-proof rubber is used between the casing 41 of the chainsaw 40 and the front grip 44. Yes. As in the first embodiment, one end of a vibration-proof coil spring is supported on the casing 41, and the vibration-proof rubber is supported on the front grip 44 in the same manner as the installation position of the vibration-proof coil spring. The free end of the anti-vibration coil spring is tightly fitted to the other end of the anti-vibration rubber so as not to be relatively rotatable.

  Even in the second embodiment, the casing 41 and the upper grip 43 can be arranged with a required gap so as not to directly contact each other. The vibration of the upper grip 43 can be reliably reduced by the presence of the vibration-proof coil spring and the vibration-proof rubber coupled with the desired gap. Thereby, the chain saw 40 can be stably and accurately operated and operated without fatigue of the operator for a long time.

  One end of the vibration isolation coil spring is supported by either one of the casing 41 or the upper grip 43, and the free end of the vibration isolation coil spring is supported by either the casing 41 or the upper grip 43. Of course, it can be tightly fitted to the anti-vibration rubber so that it cannot rotate relative to the anti-vibration rubber.

  The above is an example of a preferred embodiment of the present invention. For example, as described above, a composite structure in which both the vibration-proof coil spring 30 and the vibration-proof rubber 31 are combined in series as the vibration-damping structure and the drive device. The object of the present invention is not limited to both the gripping device and the drive device or the gripping device in relation to other factors such as the installation position of a member that generates vibration. Of course, it can be fully achieved. Therefore, the present invention is naturally not limited to the above-described embodiments, and various design changes can be made within the scope described in each claim.

  It can be used for various portable manual working machines having an engine part and an operation handle part.

1 is an external perspective view of a brush cutter according to a first exemplary embodiment of the present invention. Example 1 It is principal part sectional drawing which shows the engine part side of the brush cutter. Example 1 It is principal part sectional drawing which shows the operation handle part side of the brush cutter. Example 1 4 is a cross-sectional view taken along line IV-IV in FIG. Example 1 It is a principal part side view which shows an example of the attachment structure of the damping member attached to the clutch housing of the engine. Example 1 FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 2. Example 1 It is a front view which shows an example of a vibration-proof rubber. Example 1 It is arrow sectional drawing of the VIII-VIII line of FIG. Example 1 It is a front view which shows an example of the anti-vibration coil spring of the state which tightly fitted the anti-vibration rubber. Example 1 FIG. 10 is a cross-sectional view taken along line XX in FIG. 9. Example 1 It is a side view of the vibration isolator rubber. Example 1 It is a disassembled side view of the operation handle part. Example 1 FIG. 4 is an enlarged cross-sectional view taken along line XIII-XIII in FIG. 3. Example 1 FIG. 4 is an enlarged cross-sectional view taken along line XIV-XIV in FIG. 3. Example 1 It is a front view which shows schematic structure of a chainsaw. (Example 2)

Explanation of symbols

1 Crusher 2 Cutter Blade 3 Engine 4 Crankshaft 5 Fan 6 Centrifugal Clutch 7 Fan Cover 8 Clutch Drum 9 Output Shaft 10 Bearing 11 Clutch Housing
11a to 11c 1st to 3rd mounting pins
11a-1, 11b-1 Rib 12 Engine cover 13 Main pipe 14 Bearing 15 Drive shaft 16 Gear case 17 Handle support case 17a Accommodating space 17b Abutting rib 17c Rubber accommodating support case 17c-1 Annular recess 17d Mounting bolt 18 Case support Plate 19 Case support cover 20 Grip device 21 Handle support bracket 22 Operation handles 23 and 24 Handle clamping members 23a and 24a Main body parts 23b and 24b Holding parts 25 Handle engagement / disengagement member 25a Engagement part 26 Long bolt 27 Insert nut 30 Vibration isolation Coil spring 31 Anti-vibration rubber 31a Cavity 40 Chain saw 41 Casing 41a Upper surface 41b Rear end surface 41c Lower surface 42 Chain with blade 43 Upper grip 44 Front grip

Claims (7)

A work tool (2), a drive device (3) connected to the work tool (2) to be drivable, and a gripping device (20) disposed between the work tool (2) and the drive device (3). And a damping member interposed between the driving device (3) and the gripping device (20) ,
One end of the main pipe (13) disposed between the work tool (2) and the driving device (3) is rotatably connected to the driving device (3), and is inserted into the pipe (13). A drive shaft (15) that is supported and rotates the drive tool (2), and a cylindrical handle support case that is supported by the main pipe (13) and the drive device (3) via the damping member ( 17)
The gripping device (20) is a portable work machine that is directly supported by the handle support case (17) ,
The damping member is
One of the drive device (3) and the gripping device (20) is supported at one end, and the other end is a free end, and the anti-vibration coil spring (30) It has a vibration isolating rubber (31) that is tightly fitted to the coil spring (30) from the free end side and that is supported at one end on the other of the drive device (3) and the gripping device (20). Do Ri,
The damping member on the drive device (3) side includes first to third damping members, and the first and second damping members are formed in an upper half centered on the drive shaft (15). The third vibration control member is disposed on a bisector between the centers of the first vibration control member and the second vibration control member. It is arranged on the circumference of the lower semicircle having different diameters opposite to the first and second damping members across the drive shaft (15), and the diameter of the upper semicircle is the diameter of the lower semicircle. A portable work machine characterized by being larger than .   The anti-vibration rubber (31) has a hollow cylindrical portion, and is disposed on either the driving device (3) or the gripping device (20) and is inserted into the hollow cylindrical portion of the anti-vibration rubber (31). The portable work machine according to claim 1, wherein the portable work machine is supported by mounting pins (11a to 11c).   The one or more hollow portions (31a) that are parallel to the center line and open at both ends thereof are provided around the hollow cylindrical portion of the anti-vibration rubber (31). Or the portable work machine of 2 description.   The portable working machine according to claim 3, wherein the hollow portion (31a) is arranged with a phase difference of a predetermined angle on the same circumference centering on a central axis of the cylindrical portion.   The portable working machine according to claim 4, wherein the hollow portion (31a) has the same size.   The cavity (31a) has a wing-shaped cross section, the adjacent cavities are spaced apart from each other, and a part thereof is arranged so as to overlap in the radial direction. The portable work machine described in 1.   The portable work machine is provided with the vibration damping member between the casing (41) of the drive unit (3) and the work machine steering grips (43, 44) fixed to the casing (41). 2. A portable work machine according to claim 1, wherein said chain saw is a chain saw (40).

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