JP4569334B2 - Work machine - Google Patents

Description

  The present invention relates to a working machine such as a hydraulic excavator provided with a counterweight and a canopy for protecting a driver on an upper swing body.

  A conventional technique and problems will be described by taking a hydraulic excavator as an example.

  FIG. 6 shows a small hydraulic excavator called a mini excavator. Reference numeral 1 denotes a crawler type lower traveling body. An upper swing body 2 is mounted on the lower traveling body 1 so as to be rotatable about a vertical axis. A boom 3, an arm 4, and a bucket 5 are mounted on a front portion of the upper swing body 2. Is mounted.

  The upper swing body 2 has a swing frame 6, and a driver seat 7 on which the operator sits, and a canopy 8 for covering the driver seat 7 from above and protecting the operator from sunlight, earth and sand, and the like. And a counterweight 9, which is a cast product, is attached to the rear end of the frame 6.

  The canopy 8 is composed of canopy columns 10 and 10 (see FIG. 8) provided on the left and right sides of the rear part, and a canopy roof 11 supported by the canopy columns 10 and 10.

Conventionally, a structure shown in Patent Document 1 is known as a mounting structure for the canopy 8. 7 and 8, a column mounting seat 12 is integrally provided on the upper surface of the counterweight 9, and brackets 13 mounted on the lower ends of both side canopy columns 10 and 10 are attached to the column mounting seat 12 at a plurality of locations. It is attached by bolts 14 and nuts 15.
JP 2004-197550 A

  However, according to this known technique, since the canopy columns 10 and 10 are directly mounted on the casting portion (the column mounting seat 12 of the counterweight 9), when the machine is overturned (at the time of 90 ° rollover or 180 °), A heavy load is concentrated locally in the column mounting portion. For this reason, it is easy to generate | occur | produce damages, such as a crack, in the load concentration part as a characteristic of a brittle casting.

  In addition, there is a risk that the column mounting portion may be fatigued due to vibration during running or working of the machine.

  As a modified form of this technique, a technique is also known in which the counterweight 9 is provided with a recess (soot) whose upper surface is open, and the canopy columns 10 and 10 are attached to the counterweight 9 while being inserted into the recess. However, since the load is concentrated on the local area of the brittle casting (canopy post mounting part) during machine overturning, running, and work, the basic problem is not solved, and a recess is provided. Since it is necessary to compensate for the weight of the counterweight, there is a problem that the thickness of the weight (dimension in the front-rear direction) must be increased.

  On the other hand, if the counterweight 9 is manufactured by forging, there is no problem in the strength of the column mounting, but if the counterweight 9 having a hollow shape including fine irregularities is forged, the cost is increased and the workability is increased. However, it is not a good idea.

  Accordingly, the present invention provides a working machine that can prevent cracking and fatigue failure of a canopy mounting portion due to local load concentration without increasing the thickness of the counterweight while using a cast counterweight. It is.

  The present invention also provides a work machine capable of obtaining canopy mounting strength that sufficiently satisfies the ROPS and TOPS standards, which are standards for canopies for protecting an operator when the machine falls over.

The invention of claim 1, the upper revolving structure which is rotatably mounted on the lower traveling body, a cast counterweight, in a working machine canopy covering the driver's seat from above is provided, separate from the counterweight includes a canopy support member formed separately as a member, the canopy support member, which has a partial cast for the counterweight, the state in which includes a strut mount seat at the top, the strut mount seat is exposed to the outside The canopy support member is fixed by casting the cast portion into the counterweight, and the canopy support is attached to the support mounting seat.

According to a second aspect of the present invention, in the configuration of the first aspect, the canopy support member is cast and fixed to the counterweight in a state where the cast portion vertically penetrates the counterweight and the lower end thereof is exposed on the lower surface side of the counterweight. The lower end of the canopy support member is configured to be attached to the swing frame of the upper swing body.

According to a third aspect of the present invention, in the configuration of the first or second aspect, the canopy support members are cast and fixed on the left and right sides of the counterweight by the cast portions, and the pair of left and right canopy columns are attached to the column mounting seats of the both side canopy support members. It is configured to be attached.

  According to a fourth aspect of the present invention, in the configuration of the third aspect, the both-side canopy support members are formed as an integrated body in which the lower end portions of each other are continuous by a horizontal connecting portion.

According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the both-side canopy support members are cast and fixed to the counterweight by the cast-in portion in a state where the coupling portion is exposed on the lower surface side of the counterweight, and the coupling portion is formed into the revolving frame. It is configured to be attached.

According to the present invention, a canopy support member formed as a separate member from the counterweight is fixed by casting into a cast counterweight by a cast-in portion, and the canopy support column is mounted on the column mounting seat provided on the canopy support member. Therefore, the load at the time of the machine overturning is supported in a wide range of the counterweight from the mounting portion through the cast-in portion of the canopy support member, and fatigue failure due to vibration during running and working of the machine hardly occurs.

  That is, there is no possibility that a large local load acts on the counterweight, and repeated loads due to vibration can be received in a distributed manner, so that breakage such as cracking is unlikely to occur even in a casting.

  In addition, since the canopy support member is cast and fixed in the counterweight by utilizing the casting, the attachment of the member itself is simple and a strong attachment state can be obtained.

  On the other hand, the counterweight can be reinforced by casting a canopy support member into the counterweight, and the counterweight can be prevented from cracking.

  Further, according to the inventions of claims 2 and 5, in order to fix the canopy support member to the revolving frame at the lower end (the connecting portion in claim 5) in addition to the cast-in portion with respect to the counterweight, As a result, the canopy mounting strength can be further increased. Therefore, canopy mounting strength that sufficiently satisfies the ROPS and TOPS standards can be obtained.

  According to the inventions of claims 3 to 5, the canopy support members are cast and fixed on both the left and right sides of the counterweight, and the canopy posts are attached to the both side canopy support members. Even for this, it is possible to ensure the high mounting strength as described above, which is more effective than a single canopy support member.

In this case, according to the inventions of claims 4 and 5,
(i) Since the both-side canopy support members are integrated at the connecting portion, the strength of the support member itself can be increased.

  (ii) The support member can be fixed to the counterweight and the load can be supported even at the cast portion of the connecting portion with respect to the counterweight.

  By these points, the load bearing force of the canopy can be further increased.

  An embodiment of the present invention will be described with reference to FIGS.

  In the following embodiment, the same parts as those in the known structure shown in FIGS.

1st Embodiment (refer FIGS. 1-3)
A canopy 19 including a counterweight 16 and a pair of left and right canopy columns 17 and 17 and a canopy roof 18 is attached to the turning frame 6 of the upper turning body 2 mounted on the lower traveling body.

  The counterweight 16 is manufactured by casting, and the canopy support members 20 and 20 are cast and fixed on the left and right sides of the counterweight 16 at the time of casting the weight.

  In this embodiment, by bending a thick plate material into a U shape, the left and right canopy support members 20 and 20 are formed as a single piece continuous by a horizontal connecting portion 21 at the lower end of each other.

  The both side canopy support members 20 and 20 are respectively provided with column support seats 22 and 22 by bending the upper ends of the both side canopy support members 20 and 20 inward and horizontally, as shown in FIG. Each bolt through hole 23 is provided.

  The canopy support members 20 and 20 penetrate the counterweight 16 in the vertical direction so that both side column mounting seats 22 and 22 protrude upward and the lower surface of the connecting portion 21 is exposed to the lower surface of the weight. It is fixed by casting.

  The connecting portion 21 is provided with screw holes 24 (see FIG. 3) at a plurality of locations in the left and right direction (two locations in the illustrated example), and when the counterweight 16 is attached to the swivel frame 6, the connecting portion 21 is the swivel frame. 6 is attached with a bolt 25.

  In this way, the both-side canopy support members 20, 20 are fixed by the cast portion (including the cast portion of the connecting portion 21) to the counterweight 16 and the bolting portion of the connecting portion 21 to the swivel frame 6.

On the other hand, for example, mounting portions 27 and 27 having a pair of bolt through holes 26 and 26 are provided at the lower ends of the both-side canopy columns 17 and 17, and these mounting portions 27 and 27 are columns of the both-side canopy support members 20 and 20. The both side canopy support pillars 17 and 17 (canopy 19) are attached to the canopy support members 20 and 20 (upper swing body 2).

  Thus, since the canopy support members 20 and 20 are fixed by casting into the cast counterweight 16, and the canopy support columns 17 and 17 are attached to the canopy support members 20 and 20, the load acting on the canopy 19 is applied. Is added to the canopy support members 20 and 20 from the canopy struts 17 and 17, and is supported in a wide range of the counterweight 16 through the cast-in portion of the member.

  Therefore, as long as the canopy support members 20 and 20 have sufficient strength, it is impossible to disperse the load at the time of machine overturning and the repeated load due to vibration at the time of running of the machine and work in a wide range of the counterweight 16. It can be supported without.

  That is, compared to the known structure shown in FIGS. 7 and 8 (structure in which the load concentrates on the column mounting seat 12 of the counterweight 9), the concentration of the load on the counterweight 16 can be prevented. Breakage such as cracks and fatigue failure are unlikely to occur.

  In addition, since the canopy support members 20 and 20 are cast and fixed in the counterweight 16 by using the casting, the members 20 and 20 can be easily attached and a strong attachment state can be obtained.

  On the other hand, casting the canopy support members 20 and 20 in the counterweight 16 also has an effect of reinforcing the counterweight 16 and suppressing cracking of the counterweight 16.

  In addition, according to this embodiment, the following effects can be obtained.

  (A) Since the both-side canopy support members 20 and 20 are integrated by the connecting portion 21, the strength of the canopy support members 20 and 20 themselves can be increased.

  (B) The canopy support members 20 and 20 can be fixed to the counterweight 16 and the load can be supported even at the cast portion of the connecting portion 21 with respect to the counterweight 16.

  (C) Since the canopy support members 20 and 20 are fixed to the revolving frame 6 at the connecting portion 21 in addition to the cast portion with respect to the counterweight 16, the mounting strength of the members 20 and 20 and thus the canopy mounting strength is further increased. Can do.

  With these points, the load bearing force of the canopy 19 can be further increased. In particular, the point (c) can sufficiently satisfy the ROPS and TOPS standards.

Second and third embodiments (see FIGS. 4 and 5)
Only differences from the first embodiment will be described.

  In the second embodiment shown in FIG. 4, both canopy support members 20, 20 are formed as separate bodies and are separately cast and fixed on the left and right sides of the counterweight 16.

  In addition, inwardly horizontal bent portions 20a, 20a are provided at the lower ends of both members 20, 20, and screw holes 24, 24 for bolting the revolving frame 6 are provided in the bent portions 20a, 20a. .

  In the third embodiment shown in FIG. 5, both side canopy columns 17, 17 are integrated by a connecting pipe 17 a attached between the lower ends of each other.

  In this case, as the means for attaching the both side canopy struts 17 and 17, in the example shown in the figure, separate attachment portions 27 and 27 are provided for the both side canopy struts 17 and 17 according to the first and second embodiments. While a common mounting portion is provided on 17a, a common column mounting seat may be provided between the upper ends of the two canopy support members 20 and 20, and a means for connecting the common mounting portion and the column mounting seat may be used.

  Further, in each of the above embodiments, a two-post canopy is illustrated, but the present invention is a three- or four-post canopy provided with one or two post in the front, or only one post. This can also be applied to other canopies. In the case of a three- or four-pillar canopy, the above-described mounting structure can be adopted for the two rear columns.

It is a partial cross section side view which shows 1st Embodiment of this invention. FIG. It is a disassembled perspective view of the counterweight and canopy support | pillar in the same embodiment. FIG. 4 is a view corresponding to FIG. 3 showing a second embodiment of the present invention. FIG. 6 is a view corresponding to FIG. 3 showing a third embodiment of the present invention. It is a schematic side view of a hydraulic excavator which is an application target example. It is a partially expanded side view which shows the canopy attachment structure by a prior art. It is the same rear view.

DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper revolving body 6 Turning frame 7 Driver's seat 16 Counterweight 19 Canopy 17,17 Canopy support | pillar 18 Canopy roof 20,20 Canopy support member 21 Connecting part 24 Screw hole of connecting part 25 Bolt 22 for connecting part attachment , 22 Prop mounting seat 23 Bolt through hole of post mounting seat 27 Canopy post mounting portion 26 Mounting bolt through hole 28 Post mounting bolt 29 Same nut

Claims (5)

In a work machine in which a cast counterweight and a canopy that covers the driver's seat from above are provided on an upper swing body that is rotatably mounted on the lower traveling body, the counterweight is formed separately as a separate member. includes a canopy support members, the canopy support member, which has a partial cast for the counterweight, comprising a strut mount seat at the top, the counter in weight of the cast part in a state where the strut mounting seat is exposed to the outside A working machine characterized in that a canopy support member is fixed by casting and the canopy support is attached to the support attachment seat. 2. The work machine according to claim 1, wherein the canopy support member is cast and fixed to the counterweight in a state where the cast portion penetrates the counterweight vertically and its lower end is exposed on the lower surface side of the counterweight. A work machine characterized in that the lower end of the machine is attached to the revolving frame of the upper revolving structure. The work machine according to claim 1, configured to the canopy support members on the left and right sides of the counterweight and fixed casting by the casting portion, mounting a pair of canopy strut to the strut mounting seat of the sides canopy support member A working machine characterized by   4. The working machine canopy mounting structure according to claim 3, wherein the both-side canopy support members are formed as an integrated body in which the lower end portions thereof are continuous by a horizontal connecting portion. In claim 4 working machine according, connecting part casting fixed to the counterweight by the lower surface side opposite sides canopy support member above cast parts in a state exposed to the counterweight, and configured to attach the connecting portion to the rotating frame A working machine characterized by that.

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