JP4097578B2 - Handle support structure for portable work machines - Google Patents

Description

  The present invention relates to a handle support structure for various portable work machines such as a brush cutter, a pruning machine, and a high branch pruning machine, and more particularly to a handle support structure for a portable work machine that can exhibit an optimum vibration damping function.

  Conventionally, various portable work machines such as a brush cutter, a pruning machine, and a high branch pruning machine are frequently used. A brush cutter handle device (see, for example, Patent Document 1) has been proposed as a portable work machine of this type. In the brush cutter disclosed in Patent Document 1, a gear case that supports a cutting blade so as to be rotatable in a horizontal direction and a centrifugal clutch of an engine are connected by a main rod having a long circular tube shape. A drive shaft supported in the main shaft is rotationally driven via the centrifugal clutch, and a work tool such as a cutting blade unit mounted on the gear case is driven via the drive shaft.

  Near the engine side of the main rod, a handle rod for supporting and operating the brush cutter is provided. As a support structure of the handle rod for manipulating the brush cutter, a pair of support rod supports facing each other with a predetermined interval are fastened and fixed to a part of the outer periphery of the main rod.

  Further, between the support supports, a handle support is supported and fixed in a floating manner via a vibration isolating rubber, and the support is supported in parallel along the main support via the vibration isolating rubber. ing. The handle rod support is clamped and fixed to the middle portion of the support rod, and the end portions of the pair of left and right handle rods are clamped and fixed in a direction perpendicular to the support rod. Yes.

  In this conventional handle support structure, as described above, the handle rod support is clamped and fixed in an immobile state with respect to the support rod, and is also supported and fixed freely with respect to the main rod. For this reason, the vibration acting on the main shaft is reduced by the anti-vibration rubber interposed between the support member and the support member, and hardly transmitted to the support member. It is assumed that vibration to the handle bar support connected to the support is reduced. The handle rod is indirectly attached to the main rod, and the vibration of the main rod is absorbed by the mounting portion of the support rod, so that the vibration acting on the handle rod is reduced.

  Further, as another structural example of the handle support structure of the brush cutter, an operation handle vibration isolator (see, for example, Patent Document 2) has been proposed. In the handle support structure disclosed in Patent Literature 2, a plurality of fittings that are inserted into the outer periphery of a part of the operating rod in a plurality of fitting grooves formed at a predetermined interval on the inner surface of the mounting bracket that fastens and fixes the operation handle. An O-ring, which is an elastic ring, is fitted, and the mounting bracket is fastened and fixed with a required gap between it and the operating rod.

In this conventional handle support structure, vibrations acting on the operating rod from the engine side or the cutter blade side are absorbed by the O-ring, and both collide with each other through a gap between the mounting bracket and the operating rod. Without vibration, vibrations to the mounting bracket and the operation handle are reduced.
Japanese Utility Model Publication No. 56-62026 Japanese Utility Model Publication No. 2-34120

  In the handle support structure disclosed in Patent Document 1, the support is supported via a vibration isolating rubber between a pair of support supports that are fastened and fixed to the outer periphery of a part of the main work as a main pipe by bolt fastening. Is supported by clamping the lower end portion of the handle rod supporter as a handle support bracket to the main rod by bolting, and further, the upper end of the handle rod supporter is fixed to the support rod. Both the pair of left and right handle rods as operation handles are fastened and fixed via bolts by bolts.

  For this reason, the number of parts to be assembled with respect to the main rod increases, and it becomes difficult to position and adjust the mutual positional relationship between the component members supporting the handle rods and the respective component members. Problems are likely to occur. In addition, many parts that are fastened and fixed to the main rod by bolting are required, and it takes time, labor, and labor to assemble the handle rod, and the operation tends to be complicated.

  In general, an excessive force due to operation or operation of a brush cutter frequently acts on an operation handle such as a handle rod. The handle rod disclosed in Patent Document 1 comprises a pair of left and right handle rods, and the end portions of the handle rods are cantilevered and fixed to the handle rod support. For this reason, it has the problem that it becomes one of the causes that the attachment intensity | strength of the said handle bar support and each handle bar becomes weak.

  On the other hand, in the handle support structure disclosed in Patent Document 2, when the operation handle is attached to the operation rod as the main pipe, a plurality of O-rings as vibration-proof rubbers are inserted into a part of the outer periphery of the operation rod, These O-rings are fitted in fitting grooves as a plurality of ring grooves concentrically formed on the inner surface of the mounting bracket as a handle support bracket, and the mounting bracket has a required gap between it and the operating rod. And fastened with bolts.

  For this reason, the technique disclosed in Patent Document 2 requires alignment of the inside of the plurality of fitting grooves of the mounting bracket and the O-ring of the operation rod, and the product has high dimensional accuracy and complicated machining. Etc. are required. For this reason, variations are likely to occur from product to product, and defective products are often generated. In addition, since the width and depth dimensions of the fitting groove that fits into the O-ring are small, as in the technique of the above-mentioned Patent Document 1, the point that it is difficult to position and adjust between components is the same as before. Absent.

  Further, the technique disclosed in Patent Document 2 is configured to be fastened and fixed in a state where an O-ring as a vibration-proof rubber is crushed in a gap between the inner surface of the mounting bracket and the operation rod. For this reason, it is extremely difficult to visually observe the interval. For this reason, it cannot be determined whether the O-ring is securely fitted in the fitting groove not only in the assembly work of the mounting bracket and the operating rod but also in the inspection after the assembly work. There are also defects. In addition, since the O-ring is squeezed and fixed in the gap between the inner surface of the mounting bracket and the operating rod, the O-ring will sag and lose its elasticity over a long period of time. It becomes difficult to sufficiently exhibit the performance of absorbing vibrations from the cutter blade side with respect to the work machine.

  The present invention has been made to solve the above-described conventional problems, and a specific object thereof is a simple structure, excellent assemblability, and further having a stable and good vibration damping function. It is an object of the present invention to provide a handle support structure for a portable work machine that can reduce vibrations generated during engine operation.

The invention according to claim 1 is a handle support structure for a portable work machine, comprising: a connection member that connects a drive device that drives a work tool and an operation handle portion; and the operation handle portion and the connection member. Two or more anti-vibration rubbers disposed between and for reducing vibrations of the operation handle part; a pair of front and rear rubber housing support cases which are externally fitted and fixed to the coupling member and accommodate and support the anti-vibration rubber; and the coupling member And a handle support bracket that is externally fitted with a required gap and is sandwiched and fixed between the pair of front and rear rubber housing support cases via the anti-vibration rubber , the rubber housing support case comprising the handle support An insertion support portion for inserting and supporting the bracket; and a case main body having two or more rubber fitting holes in the periphery of the insertion support portion for fitting the anti-vibration rubber. Lifting bracket, the handle support structure of a portable working machine, characterized in that through each rubber cushion which is fitted into the rubber fitting Chakuana is the handle support bracket comprising a mounting pin which is supported is there.

  The invention according to claim 2 is the invention according to claim 1, wherein the rubber housing support case and the handle support bracket are sandwiched and fixed to the connecting member, supported by the outer surface of the rubber housing support case. It further has a pair of clamp members.

The invention according to claim 3 is the invention according to claim 2, wherein the case main body of the rubber housing support case further has a clamp fitting hole arranged at a fitting position of the clamp member, The clamp member includes an attachment boss that is fitted and fixed in the clamp fitting hole, and a clamp body that clamps and fixes the outer periphery of the coupling member.

The invention according to claim 4 is the invention according to claim 1 , wherein the anti-vibration rubber has a large-diameter portion and a small-diameter portion integrally connected via a step portion, and along the center line. While having a pin insertion hole consisting of a blind hole of the same diameter entering the small diameter part from the large diameter part, a plurality of hollow parts penetrating in the center line direction are formed around the blind hole of the large diameter part, The rubber fitting hole of the rubber containing support case has a contact step portion that contacts an annular step surface formed between the large diameter portion and the small diameter portion of the anti-vibration rubber. It is characterized by.

The invention according to claim 5 is the invention according to claim 1 or 4 , wherein the anti-vibration rubber is arranged at the same interval on the same circumference centering on the central axis of the rubber containing support case. It is characterized by having. As in the invention according to claim 6, it is preferable that the anti-vibration rubber is supported at three points on the same circumference around the central axis of the rubber housing support case.

The invention according to claim 7 is the invention according to any one of claims 1, 4 to 6, wherein the anti-vibration rubber has the same size.

  The invention according to claim 1 includes various portable manual work machines such as a brush cutter, a pruning machine, and a high branch pruning machine. Generally, in the portable work machine, work is performed by operating and manipulating an operation handle disposed between a work tool and a drive device via a handle support bracket. At this time, extremely large vibrations and shocks from the work tool and the driving device are transmitted to the operation handle from various directions, and vibrations and shocks transmitted to the operation handle are transmitted to the operator's hands and arms. Is transmitted to. Therefore, the vibration applied to the worker becomes extremely large.

  When arranging a vibration control structure between the driving device and the operation handle, direct contact is surely avoided so that direct contact does not occur between the component that generates vibration and the operation handle. Is essential. In the present invention, a pair of front and rear rubber accommodating support cases are externally fitted and fixed to a connecting member that couples the driving device and the operation handle, and two or more rubber accommodating support cases accommodated and supported by the respective rubber accommodating support cases. One feature is that the handle support bracket is clamped and fixed to the connecting member with a predetermined gap via a vibration-proof rubber. Accordingly, the handle support bracket can be indirectly supported by the connecting member with a required gap, and the operation handle can be directly supported with respect to the handle support bracket.

  By providing the above configuration, the handle support bracket can be indirectly supported with respect to the coupling member and the drive device in combination with the gap, and intermittent impact of the work tool during operation, vibration of the drive device, etc. Transmission to the operating handle can be reduced. Therefore, even under various environments such as changes in the work range and the presence or absence of obstacles, work can be performed with the optimal operability and maneuverability of the work machine according to the work content and work conditions, etc. Workers' fatigue can be reduced, and work efficiency and the like are significantly improved.

The handle support bracket is inserted and supported in the insertion support portion of the rubber storage support case, and the mounting pin of the handle support bracket is inserted into the rubber insertion hole of the rubber storage support case via the vibration isolating rubber. Insertion is supported. With this configuration, the handle support bracket can be easily inserted and supported between the rubber housing support cases. Furthermore, the vibration-proof rubber and the handle support bracket can be easily and stably connected with a small number of members.

By providing the above configuration, the rubber housing support case and the handle support bracket can be assembled as a single unit, and can be unitized with respect to the connecting member. For this reason, even when the rubber accommodating support case and the handle supporting bracket are assembled to the connecting member, the handle supporting bracket is provided between the rubber accommodating support cases with a simple structure without requiring any special fixing means. It can be positioned and supported. Therefore, the assembling property and handling property at the time of manufacturing and maintenance inspection of the working machine can be sufficiently enhanced.

The rubber housing support case and the handle support bracket are preferably clamped and fixed to a pair of front and rear clamp members as in the invention according to claim 2. By supporting each clamp member on the outer surface of the rubber housing support case opposite to the handle support bracket, both the rubber housing support case and the handle support bracket can be easily and It becomes possible to be securely clamped and fixed.

The invention according to claim 3 is characterized in that the mounting boss of the clamp member is fitted and supported in a clamp fitting hole arranged in parallel and adjacent to the rubber fitting hole of the rubber accommodating support case, Is clamped and fixed to the outer periphery of the connecting member. With this configuration, the clamp member can be easily positioned and supported on the outer surface of the rubber housing support case, and the rubber housing support case and the handle support bracket can be easily fixed to the connecting member. And can be made strong.

According to the fourth aspect of the present invention, as the anti-vibration rubber, the anti-vibration rubber includes a step portion in which a large-diameter portion and a small-diameter portion are integrally connected via a step portion. It has a shape. Further, a pin insertion hole comprising a blind hole of the same diameter entering the small diameter portion from the large diameter portion along the center line, and a plurality of cavities around the blind hole of the large diameter portion and penetrating in the center line direction Part.

  By forming the hollow portion in the large-diameter portion, the anti-vibration rubber is easily elastically deformed in many directions, and the vibration damping function can be improved. Due to the presence of the hollow portion, even if a large external force is applied to the work machine from various directions such as vibration and impact, the vibration-proof rubber can be secured, so that the work machine can be used when the engine is operating or when the operation is performed. The vibration transmitted to the operation handle can be kept low. The degree of elasticity of the anti-vibration rubber can be changed to a desired elastic force by adjusting the size, form, number of arrangement, installation position, and the like of the cavity.

  Since the operation handle is steered in various directions during operation, it becomes easy to sag simply by forming a hollow portion with respect to the anti-vibration rubber, and the elasticity of the anti-vibration rubber is lost for a long time. There is a risk. In the present invention, by forming the pin insertion hole of the anti-vibration rubber as a blind hole, it is possible to ensure the rigidity at the small-diameter portion of the anti-vibration rubber while securing the elastic force at the large-diameter portion. And the strength of the anti-vibration rubber can be increased.

  The structure of the small-diameter portion in the present invention can increase the strength of the anti-vibration rubber to a desired state and maintain the required form even with a large external force acting from various directions to ensure the damping performance. can do. In particular, deformation of the anti-vibration rubber in the center line direction can be suppressed, and in combination with the action of the hollow portion, a required form as the anti-vibration rubber can be maintained and a high level of vibration control performance can be secured. become.

  Further, the rubber fitting hole of the rubber accommodating support case has an abutting step portion that abuts on an annular step portion formed between the large diameter portion and the small diameter portion of the anti-vibration rubber. Thus, a sufficient space can be secured in the rubber fitting hole to accommodate the large diameter portion of the anti-vibration rubber. Accordingly, the degree of freedom in designing the hollow portion is increased, and the elasticity of the large-diameter portion can be sufficiently secured in combination with the hollow portion.

The invention according to claim 5 is characterized in that the anti-vibration rubber is arranged at the same interval on the same circumference centering on the central axis of the rubber accommodating support case. Furthermore, the invention according to claim 6 is characterized in that three points are supported on the same circumference centering on the central axis of the rubber accommodating support case. Furthermore, the invention according to claim 7 is characterized in that the anti-vibration rubber has the same size.

  Due to the unique configuration of the present invention, the vibration isolating rubber can absorb the vibration transmitted to the operation handle by its elastic force, and the handle support bracket can be stably attached to the vibration isolating rubber. It can be held securely. For this reason, even if a large external force such as vibration or impact acts on the handle support bracket from various directions, the mounting strength of the operation handle in the handle support bracket can be sufficiently secured.

Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings.
FIG. 1 is an overall perspective view showing an external appearance of a brush cutter according to a typical embodiment of the present invention, FIG. 2 is a cross-sectional view of an essential part showing an engine portion side of the brush cutter, and FIG. 3 is an operation handle portion of the brush cutter. It is principal part sectional drawing which shows the side. In this embodiment, a brush cutter is described as an example of the portable work machine. However, the present invention is not limited to this, and various portable manual devices such as a pruning machine and a high branch pruning machine are used. It can also be applied to work machines.

  In FIG. 1, the code | symbol 1 has shown the trimming machine provided with the engine 3 which rotationally drives the cutter blade 2. As shown in FIG. As shown in FIG. 2, a fan 5 and a centrifugal clutch 6 are respectively fixed to the crankshaft 4 of the engine 3. The fan cover 7 including the fan 5 is fixed to the engine cover 8, and the clutch housing 12 is fixed to the engine cover 8. The clutch housing 12 rotatably supports a cylindrical output shaft 10 of a clutch drum 9 including the centrifugal clutch 6 via a bearing 11.

  An intermediate cylinder 14 is inserted into the front end cylindrical portion of the clutch housing 12 via a cylindrical anti-vibration rubber 13. A rear end portion of a long circular main pipe 15 as a connecting member is inserted into the intermediate cylinder 14. The intermediate cylinder 14 is fastened and fixed on the outer peripheral surface of the main pipe 15 by a bolt 16 that passes through a bolt hole that penetrates in a direction orthogonal to the center line of the main pipe 15. The front end cylindrical portion, the intermediate cylinder 14 and the main pipe 15 of the clutch housing 12 are fastened and fixed by positioning bolts (not shown) that pass through bolt holes (not shown) penetrating in a direction perpendicular to the center line of the main pipe 15. Has been.

  The clutch housing 12 is covered with a cover member 17 having a substantially polygonal cross section. The cover member 17 is formed such that the cross-sectional shape of the insertion opening on the engine side is a smooth curved surface on the inside, and the curvature shape of the curved surface is formed so as to be integrated with the modeling line of the engine cover 8. Yes. The cover member 17 is positioned and supported via contact ribs that contact the peripheral edge of the tip cylindrical portion of the clutch housing 12, and is fastened and fixed to the engine cover 8 by bolting.

  As shown in FIG. 3, a drive shaft 18 is rotatably supported inside the main pipe 15 via a plurality of bearings 19,. As shown in FIG. 2, the rear end of the drive shaft 18 is inserted into the cylindrical output shaft 10 of the clutch drum 9 and is splined. A gear case 20 that rotatably supports and fixes the cutter blade 2 is connected and fixed to the distal end portion of the main pipe 15, and the distal end portion of the drive shaft 18 is a reduction gear (not shown) built in the gear case 20. It is connected to.

  A shoulder band mounting bracket 21 and an operation handle portion 30 are provided on the engine side portion of the main pipe 15, respectively. The components of the trimming machine 1 configured as described above are the same as the conventional ones except for the handle support structure of the operation handle portion 30, and the present invention is limited to the illustrated example. It is not something.

  The configuration of the handle support portion of the operation handle portion 30 is the most important feature of the present invention. The handle support portion of the present invention includes two or more anti-vibration rubbers 31,..., 31 that reduce vibration of the operation handle portion 30, and a pair of front and rear rubber housing support cases 32 and 32 that house and support the anti-vibration rubber 31. A handle support bracket 33 inserted and supported between the rubber storage support cases 32 via the anti-vibration rubber 31 and the rubber storage support case 32 and the handle support bracket 33 are sandwiched and fixed to the main pipe 15. A pair of front and rear clamp members 34 are provided. In the illustrated example, the operation handle portion 30 includes the rubber housing support case 32 and the operation handle 35 having a substantially U shape that is fastened and fixed to the handle support bracket 33 by bolting. The handle 35 is not limited to a substantially U shape, and can take various shapes.

  4 to 7 show elastic rubbers which are one of the main components of the handle support part. FIG. 4 is a front view of the elastic rubber, FIG. 5 is a side view of the elastic rubber, and FIG. 4 is a cross-sectional view taken along the line VI-VI in FIG. 4, and FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 8 to 10 show examples of the curved structure of the handle support portion, respectively. 8 is an exploded perspective view of components constituting the handle support portion, FIG. 9 is a longitudinal sectional view of the handle support portion assembled, and FIG. 10 is a cross-sectional view taken along the line XX of FIG.

  4 to 7, the outer shape of the elastic rubber 31 is such that a large-diameter portion 31a and a small-diameter portion 31b are integrally formed via an annular step portion 31c, and the large-diameter portion 31b is formed along the center line. A circular blind hole 31d having the same diameter extending from the diameter part 31a to a part of the small diameter part 31b is formed. The blind hole 31d is formed as a pin insertion hole for attaching the handle support bracket.

  On the periphery of the blind hole 31d of the large-diameter portion 31a, there are formed hollow portions 31e, ..., 31e that form a plurality of cylinders penetrating in the center line direction. One end of each hollow portion 31e in the center line direction coincides with the outer peripheral surface of the small diameter portion 31b and extends in the center line direction across the peripheral surface of the stepped portion 31c. These extending portions are on the same center line as the hollow portion 31e, and form semicircular arc-shaped groove portions 31f, ..., 31f.

  The hollow portion 31d facilitates elastic deformation of the elastic rubber 31 itself in all directions, and improves the vibration damping function of the elastic rubber 31. Due to the presence of the hollow portion 31d, even if a large external force acts on the brush cutter 1 from various directions, it is possible to ensure the flexibility of the anti-vibration rubber 31 and to operate the handle when the engine is operating or working. The vibration to 35 can be suppressed low.

  An optimal vibration damping function can be obtained by appropriately setting the hardness and the like of the vibration-proof rubber 31 based on work conditions and the like. The degree of elastic force of the anti-vibration rubber 31 can be arbitrarily adjusted by adjusting the size, form, number of arrangement, installation position, and the like of the hollow portion 31d.

  Since the operation handle 35 is steered in all directions at the time of operation, it is easy to sag simply by forming the cavity 31e with respect to the anti-vibration rubber 31, and the anti-vibration rubber during long-term use. There is a risk that the elasticity of 31 will be lost.

  In the illustrated example, by forming the pin insertion hole of the anti-vibration rubber 31 as a blind hole 31d, the elasticity of the large-diameter portion 31a can be ensured, and the rigidity in the small-diameter portion 31b can be ensured. The strength of the anti-vibration rubber 31 is increased. The presence of the small-diameter portion 31b can increase the strength of the anti-vibration rubber 31 to a desired strength, and even if an external force acts from many directions, deformation of the anti-vibration rubber 31 in the center line direction is suppressed. Thereby, coupled with the hollow portion 31e, the vibration isolating rubber 31 can maintain a required form and sufficiently obtain a vibration damping performance. Therefore, vibrations acting on the main pipe 15 from the engine side or the cutter blade side can be absorbed by the vibration isolating rubber 31.

  As shown in FIGS. 8 to 10, the rubber housing support case 32 has a case main body 32a formed of a substantially triangular shell having three arcuate corners and a central axis of the case main body 32a. The rubber insertion support portions 32b disposed on the left and right in FIG. 8 have the same structure.

  The insertion support portion 32b is inserted into the outer peripheral surface of the main pipe 15, and as shown in FIG. 9, the case main body 32a when the end surfaces of the insertion support portions 32b come into contact with each other and are in close contact with each other. The distance between the opposing surfaces is set to a distance dimension that does not contact the end surface of the handle support bracket 33.

  As shown in FIGS. 8 and 9, circular blind holes for accommodating and supporting the elastic rubber 31 are provided on the periphery of the case main body 32 a on the opposite surface of the corner portion and centered on the insertion support portion 32 b. Shaped rubber fitting holes 32c are formed adjacent to each other in parallel. Three rubber fitting holes 32c are provided for convenience, and are arranged at the same interval on the same circumference centering on the central axis of the case body 32a.

  The rubber fitting hole 32 c has a contact step portion that contacts the step surface of the step portion 31 c of the elastic rubber 31. The elastic rubber 31 is supported at three points on the same circumference around the central axis of the case main body 32a so as not to rotate relative to each other at the same interval. Of the three rubber fitting holes 32c, one rubber fitting hole 32c is directly below the insertion support portion 32b on a bisector between the centers of the other two rubber fitting holes 32c. It is preferable to arrange in Note that the elastic rubber 31 is not limited to three-point support, and may be configured to support at a plurality of points such as four-point support, five-point support, and the like. Further, the form of the rubber housing support case for housing the elastic rubber 31 is not limited to a substantially triangular shape, and may be configured to have a substantially polygonal shape or the like.

  Thus, since the rubber fitting hole 32c has a contact step portion that contacts the step portion 31c of the vibration isolating rubber 31, the rubber fitting hole 32c accommodates the large diameter portion 31a. A sufficient space can be secured. Therefore, the degree of freedom of design for the hollow portion 31e is increased, and the elastic force in the large-diameter portion 31a of the vibration isolating rubber 31 can be sufficiently secured in combination with the configuration of the hollow portion 31e.

  Further, the rubber housing support case 32 has three circular clamp fitting holes 32d,..., 32d extending in parallel with the rubber fitting holes 32c between the rubber fitting holes 32c. Are formed penetrating in the front-rear direction. The clamp fitting hole 32d positions and supports the clamp member 34, and is set smaller than the diameter of the rubber fitting hole 32c.

  Each clamp fitting hole 32d is also arranged at the same interval on the same circumference with a phase difference of 120 ° in the circumferential direction around the central axis of the case main body 32a. Of the three clamp fitting holes 32d, one clamp fitting hole 32d is directly above the insertion support portion 32b on the bisector between the centers of the other two clamp fitting holes 32d. It is desirable to distribute it.

  The handle support bracket 33 includes a bracket body 33a having a substantially triangular flange substantially the same shape as the outer shape of the case body 32a on the outer peripheral edges on both the front and rear sides of the cylindrical cavity, and is fastened to the bracket body 33a by bolting. It is comprised by two members with the handle | steering-wheel attaching / detaching part 33b fixed.

  Recesses 33a-1 and 33b-1 each having a semicircular arc surface extending in a direction orthogonal to the cylindrical cavity of the bracket body 33a are formed on the opposing surfaces of the bracket body 33a and the handle attaching / detaching portion 33b. Has been. The upper half and the lower half of the operation handle 35 are closely fitted between the recesses 33a-1 and 33b-1, and are fastened and fixed by bolting.

  The inner diameter of the cylindrical cavity portion of the bracket body 33a is set larger than the outer diameter of the insertion support portion 32b of the rubber housing support case 32. As shown in FIG. 8, cylindrical mounting pins 33 c,..., Equal to the installation interval of the rubber fitting holes 32 c of the rubber housing support case 32, are provided at the three corners of the bracket body 33 a arranged on the left and right. 33c is protrudingly provided.

  With this configuration, the handle support bracket 33 can be easily inserted and supported between the rubber housing support cases 32, and the vibration isolating rubber 31 and the handle support bracket 33 are easily and stably coupled. And can be done reliably.

  When the mounting pin 33c is inserted and supported in the rubber fitting holes 32c of the pair of front and rear rubber housing support cases 32, 32 via the vibration isolating rubber 31, the inner peripheral surface of the bracket body 33a has an annular gap 36. Arranged on the outer peripheral surface of the main pipe 15. Accordingly, the handle support bracket 33 is indirectly supported by the main pipe 15 with the gap 36.

  By assembling the rubber housing support case 32 and the handle support bracket 33 into a single configuration, the main pipe 15 can be unitized. Thus, even when the rubber housing support case 32 and the handle support bracket 33 are assembled to the main pipe 15, the handle support bracket is provided between the rubber housing support cases 32 with a simple structure without requiring any special fixing means. 33 can be positioned and supported. For this reason, the assembling property and handling property at the time of manufacturing and maintenance inspection of the brush cutter 1 can be improved.

  The handle support portion of the operation handle portion 30 according to the illustrated example can indirectly support the handle support bracket 33 on the engine 3 and the main pipe 15 in combination with the gap 36. 35 can be supported directly.

  Accordingly, it is possible to configure so that intermittent impacts from the brush cutter 1 during operation and vibrations of the engine 3 do not directly act on the operation handle 35, and vibration transmitted to the operation handle 35 is reduced. be able to. Therefore, even under various environments such as changes in the work range and presence / absence of obstacles, it is possible to obtain the optimum operability and maneuverability of the brush cutter 1 in accordance with the work content and work conditions. The operator's fatigue can be greatly reduced, and the work efficiency can be remarkably improved.

  The pair of clamp members 34, 34 is configured by an annular clamp body 34a having a bolt tightening portion 34b partially cut away in the radial direction and spaced from each other as shown in FIG. The pair of clamp members 34, 34 both have the same structure.

  The bolt tightening portion 34 b has a bolt hole penetrating in the direction orthogonal to the central axis of the drive shaft 18 on the outer peripheral surface of the main pipe 15, and passes through the bolt hole with respect to the main pipe 15. Tightened by tightening the bolts.

  Conveniently, three cylindrical mounting bosses 34c,..., 34c project from the opposing surface of the rubber housing support case 32 of the clamp body 34a. The mounting boss 34c is disposed at a position corresponding to the clamp fitting hole 32d of the rubber housing support case 32, and is fitted and supported so as not to rotate relative to the clamp fitting hole 32d.

  The mounting boss 34c is fitted and supported in the clamp fitting hole 32d, and the clamp body 34a is fastened and fixed to the outer periphery of the main pipe 15 by bolting. The clamp member 34 can be easily positioned and supported. In addition, the rubber housing support case 32 and the handle support bracket 33 can be easily and reliably fixed to the main pipe 15.

  In the illustrated example, the pair of left and right rubber housing support cases 32 and the handle support bracket 33 are sandwiched and fixed between the pair of left and right clamp members 34 with respect to the main pipe 15. The structure is not limited to these configurations. For example, the clamp member 34 may be fixedly integrated with the outer surface of the rubber housing support case 32 opposite to the handle support bracket 33 to form a unit.

  In this case, for example, both the main pipe 15 and the clamp member 34 can be fastened and fixed by bolting through a bolt hole penetrating in a direction perpendicular to the center line of the main pipe 15. Of course, various fixing structures that can fix the handle support bracket 33 between the rubber housing support cases 32 in an immobile state can be used for the main pipe 15.

  The above is a description of a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiment, and includes, for example, a connecting member that connects a driving device that drives a work tool and an operation handle portion. The handle support structure can be used in various portable manual working machines such as a pruning machine and a high branch pruning machine. Further, the rubber housing support case 32, the handle support bracket 33, and the clamp member 34 are not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention. I understand.

1 is an overall perspective view showing an external appearance of a brush cutter that is a representative embodiment of the present invention. It is principal part sectional drawing which shows the engine part side of the brush cutter. It is principal part sectional drawing which shows the operation handle part side of the brush cutter. It is a front view of the elastic rubber which comprises some handle | steering-wheel support parts of the brush cutter. It is a side view of the elastic rubber. It is arrow sectional drawing of the VI-VI line of FIG. It is arrow sectional drawing of the VII-VII line of FIG. It is a disassembled perspective view of the components which comprise the handle | steering-wheel support part. It is a longitudinal cross-sectional view of the state which assembled the handle | steering-wheel support part. FIG. 10 is a cross-sectional view taken along line XX in FIG. 9.

Explanation of symbols

1 Crusher 2 Cutter Blade 3 Engine 4 Crankshaft 5 Fan 6 Centrifugal Clutch 7 Fan Cover 8 Engine Cover 9 Clutch Drum 10 Output Shaft 11 Bearing 12 Clutch Housing 13 Antivibration Rubber 14 Intermediate Tube 15 Main Pipe 16 Bolt 17 Cover Member 18 Drive Shaft 19 Bearing 20 Gear case 21 Shoulder band mounting bracket 30 Operation handle portion 31 Anti-vibration rubber 31a Large diameter portion 31b Small diameter portion 31c Stepped portion 31d Blind hole 31e Hollow portion 31f Groove portion 32 Rubber housing support case 32a Case body 32b Insertion support portion 32c Rubber fitting hole 32d Clamp fitting hole 33 Handle support bracket 33a Bracket body 33a-1 Recess 33b Handle detachment part 33b-1 Recess 33c Mounting pin 34 Clamp member 34a Clamp body 34b Bolt tightening part 34c Mounting boss 35 Operation handle 36 Gap

Claims (7)

A handle support structure for a portable work machine,
A connecting member (15) for connecting the driving device (3) for driving the work tool (2) and the operation handle part (30);
Two or more anti-vibration rubbers (31) disposed between the operation handle part (30) and the connecting member (15) to reduce vibration of the operation handle part (30);
A pair of front and rear rubber housing support cases (32, 32) that are fitted and fixed to the connecting member (15), and house and support the anti-vibration rubber (31), respectively;
A handle support that is externally fitted to the connecting member (15) with a required gap (36) and is sandwiched and fixed between the pair of front and rear rubber housing support cases (32, 32) via the vibration isolating rubber (31). With bracket (33),
The rubber housing support case (32) includes an insertion support portion (32b) for inserting and supporting the handle support bracket (33), and the anti-vibration rubber (32b) around the insertion support portion (32b). A case body (32a) having two or more rubber fitting holes (32c) for fitting each of 31),
The handle support bracket (33) has a mounting pin (33c) for supporting the handle support bracket (33) via each anti-vibration rubber (31) inserted into the rubber fitting hole (32c). Become
A handle support structure for a portable work machine.   A pair of front and rear clamp members (34) supported on the outer surface of the rubber housing support case (32) and sandwiching and fixing the rubber housing support case (32) and the handle support bracket (33) to the connecting member (15). 34) The handle support structure according to claim 1, further comprising: The case main body (32a) of the rubber housing support case (32) further has a clamp fitting hole (32d) arranged at a fitting position of the clamp member (34),
The clamp member (34) has a mounting boss (34c) that is fitted and supported in the clamp fitting hole (32d) and a clamp body (34a) that clamps and fixes the outer periphery of the connecting member (15). Become
The handle support structure according to claim 2, wherein: The anti-vibration rubber (31) has a large-diameter portion (31a) and a small-diameter portion (31b) integrally connected via a step portion (31c), and the large-diameter portion (31a) along the center line thereof. A pin insertion hole (31d) consisting of a blind hole of the same diameter that enters the small diameter portion (31b) from a plurality of hollow portions that penetrate in the center line direction around the blind hole of the large diameter portion (31a) ( 31a) is formed,
The rubber fitting hole (32d) of the rubber containing support case (32) has an annular shape formed between the large diameter portion (31a) and the small diameter portion (31b) of the vibration isolating rubber (31). It has a contact step portion that contacts the step surface,
The handle support structure according to claim 1 . The handle according to claim 1 or 4 , wherein the anti-vibration rubber (31) is arranged at the same interval on the same circumference centering on the central axis of the rubber accommodating support case (32). Support structure. 6. The handle support structure according to claim 5, wherein the anti-vibration rubber (31) is supported at three points on the same circumference around the central axis of the rubber accommodating support case (32). The handle support structure according to any one of claims 1 to 4 , wherein the anti-vibration rubber (31) has the same size.

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