JP7632159B2 - Work Machine - Google Patents

Description

The present invention relates to a work machine, such as a construction machine, that has a liftable cab.

Conventionally, as in Patent Document 1, for example, a work machine is known in which multiple hydraulic cylinders for raising and lowering the upper divided box are interposed between the upper divided box and the lower divided box, vertically connecting the floor surface and the ceiling in the cab, and the upper divided box can be easily raised and lowered via these cylinders.

As shown in Patent Document 2, a work machine is known that has a cab that can be raised and lowered, which is arranged at the front of the machine body and includes a cab deck on which the cab is placed, a platform arranged on the work machine body behind the cab and equipped with guide rails that guide the raising and lowering of the cab deck, and a cylinder that raises and lowers the cab deck, and the cab deck has a placement portion that faces approximately horizontally and places the cab on it, a vertical portion that stands on the placement portion, and a moving member for moving on the guide rail. In this work machine, the tip of the rod is connected to the upper end of the vertical portion.

Japanese Utility Model Application Publication No. 4-125921 JP 2015-40437 A

However, in conventional work machines, the tip of the rod is only connected to the upper end of the vertical part, so if this connection breaks, the cab will fall along the guide rail, which is a problem.

The present invention was made in consideration of these points, and its purpose is to prevent the cab from immediately falling even if the connection between the hydraulic cylinder and the cab is damaged.

To achieve the above objective, the present invention provides a fall prevention member that prevents the cab from falling.

Specifically, in the first invention,
a cab deck arranged in a liftable manner at the front of the work machine body and on which a cab is placed;
a platform disposed on the work machine body behind the cab and having a guide rail for guiding the lifting and lowering movement of the cab deck;
a hydraulic cylinder having a lower end portion fixed to the frame or the working machine body and configured to raise and lower the cab deck,
The cab deck is
a horizontally extending placement portion on which the cab is placed;
a cylinder connection portion provided upright at a rear portion of the mounting portion;
a guided portion provided at a rear end of the placement portion or at a cylinder connection portion and movable along the guide rail;
an upper end of the hydraulic cylinder is connected to the cylinder connecting portion via a connecting bracket provided at an upper end of the cylinder connecting portion;
The connecting bracket and the upper end of the cylinder are covered from above by a top plate portion of a fall prevention member provided at the upper end of the cylinder connecting portion.

With the above configuration, even if the welded portion of the connection bracket that connects the upper end of the hydraulic cylinder to the cylinder breaks, or the cylinder connection pin that connects the upper end of the cylinder to the connection bracket breaks, the connection bracket and the upper end of the cylinder are covered from above by the top plate of the fall prevention member provided at the upper end of the cylinder connection part, and this fall prevention member rests on the upper end of the cylinder to support the weight of the cab, so the cab will not immediately fall.

In a second aspect of the present invention, in the first aspect of the present invention,
The fall prevention member has a lower end portion fixed to the cylinder connection portion below the welded portion of the connection bracket, and a middle portion extending upward along the cylinder connection portion.

With the above configuration, even if the welded portion of the connection bracket breaks, the lower end of the fall prevention member remains fixed to the cylinder connection portion without being affected by the break, so the cab is supported by the hydraulic cylinder with the top plate portion of the fall prevention member resting on the connection bracket and the upper end of the cylinder.

In a third aspect of the present invention, in the first or second aspect of the present invention,
The lower surface of the top plate of the fall prevention member is spaced a predetermined distance above the connecting bracket and the upper end of the cylinder.

According to the above configuration, if the welded portion of the connection bracket that connects the upper end of the hydraulic cylinder breaks, or if the cylinder connection pin that connects the upper end of the cylinder to the connection bracket breaks, the cab will fall a specified distance before the top plate collides with the connection bracket or the upper end of the cylinder, and the impact and sound will alert the operator to the abnormality. This prevents the operator from continuing work without noticing the damage, which could lead to damage to the fall prevention member as well.

In a fourth aspect of the present invention, in any one of the first to third aspects of the present invention,
The edge of the top plate of the fall prevention member is provided with a side-slip prevention edge that extends downward and prevents the top plate, which has climbed up onto the connecting bracket and the upper end of the cylinder, from coming off.

With the above configuration, even if the connecting bracket and its surroundings are deformed to a certain extent when broken, the anti-slip edge extending downward from the edge of the top plate of the fall prevention member can prevent the connecting bracket and the top plate that has climbed up onto the upper end of the cylinder from sliding sideways and coming off, further improving safety in the event that the connection with the upper end of the cylinder is damaged.

In a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention,
The cylinder upper end of the hydraulic cylinder is pin-connected to the connecting bracket by a cylinder connecting pin,
At least a part of the fall prevention member covers the axial side surface of the cylinder connecting pin at the upper end of the cylinder, and has a cylinder connecting pin insertion hole or notch in the portion through which the cylinder connecting pin is inserted.

With the above configuration, even if the fall prevention member covers the axial side of the cylinder connection pin at the upper end of the cylinder, the cylinder connection pin can be inserted through the cylinder connection pin insertion hole or notch, so the cylinder connection pin can be removed and attached without being hindered.

As described above, according to the present invention, the connecting bracket at the rear of the cab deck on which the cab sits and the upper end of the hydraulic cylinder that raises and lowers the cab deck are covered from above by the top plate of the fall prevention member provided at the upper end of the cylinder connection part, so that even if the connection part between the hydraulic cylinder and the cab is damaged, the cab will not immediately fall.

FIG. 2 is a side view showing an upper rotating body of the work machine with the cab in a lowered position. FIG. 2 is a side view showing an upper rotating body of the work machine with the cab in a raised position. FIG. 4 is an enlarged perspective view showing the placement portion, the cylinder connection portion, and the platform when the cab is in a raised position. FIG. 4 is an exploded perspective view showing the placement portion, the cylinder connection portion, and the platform with the cab in a lowered position. FIG. 4 is an enlarged perspective view showing a rail and a guided portion. 1 is an enlarged perspective view showing a fall prevention member and its surroundings according to an embodiment of the present invention; 2 is an enlarged side view showing a fall prevention member and its surroundings according to an embodiment of the present invention. FIG. 1 is an exploded perspective view showing an enlarged view of a fall prevention member and its surroundings according to an embodiment of the present invention. 1 is an enlarged perspective view showing a fall prevention member and its surroundings according to a first modified example of an embodiment of the present invention. FIG. 10 is an enlarged side view showing a fall prevention member and its surroundings according to a first modified example of an embodiment of the present invention. FIG. 1 is an exploded perspective view showing an enlarged view of a fall prevention member and its surroundings according to a first modified example of an embodiment of the present invention. FIG. 11 is an enlarged perspective view showing a fall prevention member and its surroundings according to a second modified example of an embodiment of the present invention. FIG. 11 is an enlarged side view showing a fall prevention member and its surroundings according to a second modified example of an embodiment of the present invention. FIG. 11 is an exploded perspective view showing an enlarged view of a fall prevention member and its surroundings according to a second modified example of an embodiment of the present invention. FIG. 11 is an enlarged perspective view showing a fall prevention member and its surroundings according to a third modified example of an embodiment of the present invention. FIG. 11 is an enlarged side view showing a fall prevention member and its surroundings according to a third modified example of an embodiment of the present invention. FIG. 11 is an exploded perspective view showing an enlarged view of a fall prevention member and its surroundings according to a third modified example of an embodiment of the present invention. FIG.

The following describes an embodiment of the present invention with reference to the drawings.

(Embodiment 1)
1 and 2 show the main parts of a hydraulic excavator 1 as a work machine according to an embodiment of the present invention, and although not shown in detail, the hydraulic excavator 1 comprises an upper rotating body 2 as the work machine main body, a lower traveling body such as crawlers and wheels, and an attachment provided at the front end of the upper rotating body 2 in a manner that allows it to be raised and lowered. The attachment is not limited to a bucket, a crusher, a magnetic fork, etc. The lower traveling body may be a structure that does not travel, such as a deck.

This upper rotating body 2 has a rotating frame 3 made of a welded structure such as steel plate, which is connected to the lower traveling body by a rotating bearing (not shown), and a cab 4 for the operator is provided to the side of the front attachment of this rotating frame 3, and can be raised and lowered. Although not shown, the cab 4 is equipped with a seat for the operator, operating levers, etc. This cab 4 is placed on a cab deck 5, and depending on the model, it may weigh more than 1 ton.

As shown in Figures 3 and 4, a vertically extending platform 7 is fixed to the rear of the cab 4 on the rotating frame 3. This platform 7 has guide rails 6 that extend approximately vertically and guide the ascending and descending movement of the cab deck 5. In some cases, the guide rails 6 may not be perpendicular to the mounting surface of the hydraulic excavator 1, but may be inclined forward or backward. In that case, the cab 4 moves forward and backward as it ascends and descends, in accordance with the inclination.

As shown in FIG. 4, the lower end of the tube 10b of the hydraulic cylinder 10 is fixed to the cylinder mounting portion 7a at the bottom of the base 7. Although not shown, hydraulic piping from the hydraulic source of the hydraulic excavator 1 is connected to the hydraulic cylinder 10 via a control valve or the like, and the hydraulic cylinder 10 is adapted to be extended or retracted by the operator. The tube 10b of the hydraulic cylinder 10 may be fixed to the upper rotating body 2 instead of the base 7.

The cab deck 5 has a platform-like mounting portion 8 extending horizontally on which the cab 4 is placed, and a cylinder connection portion 9 standing approximately vertically at the rear of the mounting portion 8. The mounting portion 8 is made of, for example, a welded structure made by welding steel plates, and at its rear end, guided portions 11 that fit into the guide rails 6 and move along the guide rails 6 are provided on both sides.

Specifically, as shown in an enlarged view in FIG. 5, the guided portion 11 includes an outer guided portion 11a that covers the outer rail portion 6a, which is provided so as to extend vertically on the outer left and right sides of the base 7, from the outer left and right sides, and an inner guided portion 11b that fits into an inner rail portion 6b that is detachably provided on the base 7 so as to be parallel to the outer rail portion 6a.

The outer rail portion 6a and the outer guided portion 11a do not themselves have the function of guiding the ascending and descending movement of the cab deck 5. Even if the inner rail portion 6b and the inner guided portion 11b become detached due to some factor, the outer rail portion 6a is hooked onto the outer guided portion 11a, and is an auxiliary mechanism to prevent the cab deck 5 and the cab from falling in the forward/backward or left/right direction.

The guide rails 6 and guided parts 11 allow the cab deck 5 to move up and down while restricting movement in the left-right and front-rear directions. Note that the shape and configuration of the guide rails 6 and guided parts 11 are not limited to this example, and may be composed of, for example, only the inner rail parts 6b and the inner guided parts 11b.

In addition, harnesses and piping that connect to electrical equipment, hydraulic components, etc. inside the cab 4 are protected by a piping protection unit 14 so as not to impede the raising and lowering movement of the cab 4.

As shown enlarged in Figures 6 to 8, the cylinder connection part 9 is primarily made of a channel steel with a C-shaped cross section that extends approximately vertically and is welded or bolted to the mounting part 8. This cylinder connection part 9 has a plate-shaped vertical part 9a that extends approximately vertically and side parts 9b that extend rearward from both sides of the vertical part, and a connection bracket 12 having a through hole 12a for inserting a pin is welded and fixed to the upper rear surface of the vertical part 9a. The connection bracket 12 is plate-shaped and extends downward in a smooth curve. The upper end of the side part 9b of the cylinder connection part 9 has a diagonally cut notch 9c, which makes it easy to connect the rod tip 10a, which serves as the upper end of the hydraulic cylinder 10. The rod tip 10a is then inserted so that the clevis through hole of the rod tip 10a is aligned with the pin insertion through hole 12a of the connection bracket 12, and the cylinder connection pin 13 is inserted through both through holes and prevented from coming out by the retaining plate 13a, so that the rod tip 10a is pin-connected to the cylinder connection part 9.

The connection bracket 12 and the rod tip 10a are covered from above by the top plate portion 21 of the fall prevention member 20 provided at the upper end of the cylinder connection portion 9.

In this embodiment, the fall prevention member 20 is, for example, a pair of cross-sectionally rectangular steel bars bent so that the corners are rounded, and a rectangular top plate portion 21 is welded to the fall prevention member main body 22. The front side of the fall prevention member main body 22 is reinforced by a front reinforcing plate 24.

The rear edge of the top plate 21 of the fall prevention member 20 is bent to form a skid prevention edge 23 that extends downward and prevents the top plate 21 from coming off the connection bracket 12 and the rod tip 10a. The skid prevention edge 23 may have a height that prevents the top plate 21 from coming off the rod tip 10a when the connection bracket 12 and its periphery are broken and the top plate 21 is placed on the rod tip 10a and the top plate 21 slides sideways. The skid prevention edge 23 may be fixed to the fall prevention member body 22 by bolt fastening or the like, or may be provided not only at the rear but also on the left and right as in the left-right skid prevention edge 123 of the following modified example 1.

The shape of the fall prevention member 20 is not limited to this, and may be as shown in the following modified examples.

As shown in FIG. 7, in this embodiment, the underside of the top plate 21 of the fall prevention member 20 is spaced a predetermined distance h above the connection bracket 12 and the rod tip 10a. The distance h is not particularly limited, but may be, for example, h = 25 mm.

Next, we will explain the function of the fall prevention member 20 according to this embodiment.

If a load is applied to the cab 4 or the like that causes deformation of the connection bracket 12 and its surroundings, the welds of the connection bracket 12 may break or the cylinder connection pin 13 may break.

Even in such a case, the weight of the cab 4 is supported by the hydraulic cylinder 10 with the top plate 21 of the fall prevention member 20 resting on the upper end of the connecting bracket 12 and the rod tip 10a, so the cab 4 will not fall immediately.

In addition, the anti-slip edge 23 formed by bending the edge of the top plate 21 prevents the top plate 21 from sliding off when it rides up onto the connection bracket 12 and the rod tip 10a, further improving safety in the event that the connection with the rod tip 10a is damaged.

In addition, while the top plate portion 21 collides with the connection bracket 12 or the rod tip 10a, the cab 4 falls a certain distance h, so the operator notices the abnormality due to the impact and sound. This prevents the operator from continuing work without noticing the damage, which could result in damage to the fall prevention member.

Therefore, with the hydraulic excavator 1 according to this embodiment, even if the connection between the hydraulic cylinder 10 and the cab 4 is damaged, the cab 4 can be prevented from immediately falling.

--Modification 1--
9 to 11 show a first modified example of the embodiment of the present invention, which differs from the above embodiment in that the shape of the fall prevention member 120 is different. In the following modified examples, the same parts as those in Figs. 1 to 8 are denoted by the same reference numerals and detailed description thereof will be omitted.

In this modified example, the fall prevention member 120 is made of a main member formed of a bent steel plate. Specifically, the fall prevention member 120 of this modified example is made of, for example, a main member formed by bending a steel plate of a predetermined thickness into an inverted L-shape in side view. The portion of the fall prevention member main body 122 that extends downward of the fall prevention member 120 may be reinforced by a pair of reinforcing ribs 124.

At the lower end of the fall prevention member 120, below the welded portion of the connection bracket 12 on the front side of the cylinder connection part 9, a plate-shaped lower end part 125 is fixed by welding or the like.

In this modified example, even if the welded portion of the connection bracket 12 breaks, the fall prevention member 120 remains fixed to the front surface of the cylinder connection portion 9 without being affected by the breakage, so the cab 4 is supported by the hydraulic cylinder 10 with the top plate portion 21 of the fall prevention member 120 resting on the connection bracket 12 and the rod tip 10a.

In other words, if the lower end 125 of the fall prevention member 120 is located close to the welded portion of the connection bracket 12, when the welded portion of the connection bracket 12 breaks, there is a possibility that a crack leading to the break may develop or that stress may be directed toward the lower end 125 of the fall prevention member 120, leading to the breakage of the lower end of the fall prevention member 120, but this has the advantage of eliminating this possibility.

The edge of the top plate 21 of the fall prevention member 120 of this modified example is bent to form a skid prevention edge 23 that extends downward and prevents the top plate 21 from coming off when it rides up on the connection bracket 12 and the rod tip 10a, but in this modified example, a left-right skid prevention edge 123 is also provided in the left-right direction. The left-right skid prevention edge 123 is provided with a cylinder pin insertion notch 123a for inserting and removing the cylinder connection pin 13.

--Modification 2--
12 to 14 show a second modification of the embodiment of the present invention, which differs from the above embodiment in that the shape of the fall prevention member 220 is different.

The rod tip 10a of the hydraulic cylinder 10 is pin-connected to the connection bracket 12 by the cylinder connection pin 13, but in this modified example, at least a portion of the fall prevention member body 222 of the fall prevention member 220 covers the axial side of the cylinder connection pin 13 (pin insertion through hole 12a) of the rod tip 10a.

Specifically, the fall prevention member 220 of this modified example is inverted U-shaped, with the fall prevention member main body 222 extending downward from each end of the top plate portion 221. The pair of left and right fall prevention member main bodies 222 are fixed by welding or the like to the portion of the side portion 9b of the cylinder connection portion 9 where the notch 9c is located.

A cylinder connection pin insertion hole 226 through which the cylinder connection pin 13 is inserted is formed through at least one of the pair of left and right fall prevention member bodies 222.

After the cylinder connection pin 13 is inserted into the pin insertion through hole 12a, it is sufficient to prevent it from falling out by the anti-slip plate 13a at the rod tip 10a, so the cylinder connection pin insertion hole 226 only needs to be provided in one of the fall prevention member bodies 222.

In this modified example, even if the fall prevention member 220 covers the axial side of the cylinder connection pin 13 at the rod tip 10a, the cylinder connection pin 13 can be inserted into the pin insertion through hole 12a through the cylinder connection pin insertion hole 226, so the work of attaching and detaching the cylinder connection pin 13 is not hindered.

--Modification 3--
15 to 17 show a third modification of the embodiment of the present invention, which differs from the above embodiment in that the shape of the fall prevention member 320 is different.

In this modified fall prevention member 320, the top plate portion 321 and the connection bracket 312 are integral, and the top plate portion 321 is detachably connected to the lower end portion 322 fixed to the cylinder connection portion 9 of the fall prevention member 320 via a screw shaft 325.

Specifically, the connection bracket 312 has the same shape as in the above embodiment, and a plate-shaped top plate portion 321 is welded to its upper surface. The top plate portion 321 has a roughly triangular rice ball shape that covers the clevis portion of the rod tip end 10a of the hydraulic cylinder 10 at least when viewed from above. A pair of bolt insertion through holes (not shown) are formed through the front side of the top plate portion 321.

The lower end 322 of this modified example is in the shape of a plate that covers the vertical portion 9a of the cylinder connection portion 9 and a portion of the side portions 9b on both sides of the vertical portion 9a. A pair of bolt insertion through holes (not shown) are formed through the lower end 322 at positions corresponding to the pair of bolt insertion through holes in the top plate portion 321, and the lower end 322 is welded and fixed to the cylinder connection portion 9 considerably below the welded portion of the connection bracket 312.

Then, the connection bracket 312, to which the top plate portion 321 is integrated, is welded to the cylinder connection portion 9, and then the screw shafts 325 are inserted into a pair of bolt insertion through holes in the top plate portion 321 and a pair of bolt insertion through holes in the lower end portion 322, and nuts 326 are fastened so as to sandwich the nuts 326 from above and below the lower end portion 322, thereby connecting the top plate portion 321 and the lower end portion 322.

In this modified example, the top plate portion 321 and the connection bracket 312 are integral, so even if the weld between the cylinder connection portion 9 and the connection bracket 312 breaks, the top plate portion 321 together with the connection bracket 312 rests on the rod tip 10a and supports the weight of the cab 4.

Other Embodiments
The present invention may be configured as follows with respect to the above embodiment.

That is, in the above embodiment, the work machine is a hydraulic excavator 1, but is not limited to this, and may be any work machine having a liftable cab, such as a crane.

In the above embodiment, the lower end of the tube 10b of the hydraulic cylinder 10 is connected to the cylinder mounting part 7a of the stand 7, but it may be reversed, with the rod tip 10a forming the lower end of the cylinder and connected to the cylinder mounting part 7a, and the upper end of the tube 10b forming the upper end of the cylinder and connected to the cylinder connection part 9 by the cylinder connection pin 13.

In the above embodiment, the lower end of the hydraulic cylinder 10 is connected to the frame 7, but in some cases, it may be connected to the upper rotating body 2 (upper frame, rotating frame).

Note that the above embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or uses.

1. Hydraulic excavator (work machine)
2. Upper rotating body (main body of the work machine)
3 Swivel frame
4 Cab
5 Cab deck
6 Guide rail
6a Outer rail part
6b Inner rail part
7. Mounting stand
7a Cylinder mounting part
8 Placement part
9 Cylinder connection
9a Vertical section
9b Side part
9c Notch
10 Hydraulic cylinder
10a Rod tip (top end of cylinder)
10b Tube (lower end of cylinder)
11 Guided portion
11a Outer guided portion
11b Inner guided portion
12 Connection bracket
12a Pin insertion through hole
13 Cylinder connecting pin
13a Anti-slip plate
14 Pipe protection section
20 Fall prevention member
21 Top plate
22 Fall prevention member body
23 Anti-skid edge
24 Front reinforcement plate
120 Fall prevention member
122 Fall prevention member body
123 Side-to-side skid prevention edge
123a Cylinder pin insertion notch
124 Reinforcement rib
125 Lower end
220 Fall prevention member
221 Top plate
222 Fall prevention member body
226 Cylinder connection pin insertion hole
312 Connection bracket
320 Fall prevention member
321 Top plate
322 Lower end
325 screw shaft
326 Nut

Claims (5)

a cab deck arranged in a liftable manner at the front of the work machine body and on which a cab is placed;
a platform disposed on the work machine body behind the cab and having a guide rail for guiding the lifting and lowering movement of the cab deck;
a hydraulic cylinder having a lower end portion fixed to the frame or the working machine body and configured to raise and lower the cab deck,
The cab deck is
a horizontally extending placement portion on which the cab is placed;
a cylinder connection portion provided upright at a rear portion of the mounting portion;
a guided portion provided at a rear end of the placement portion or at a cylinder connection portion and movable along the guide rail;
an upper end of the hydraulic cylinder is connected to the cylinder connecting portion via a connecting bracket provided at an upper end of the cylinder connecting portion;
A working machine characterized in that the connection bracket and the upper end of the cylinder are covered from above by a top plate portion of a fall prevention member provided at the upper end of the cylinder connection portion. The work machine described in claim 1, characterized in that the lower end of the fall prevention member is fixed below the welded portion of the connection bracket at the cylinder connection portion, and the middle portion extends upward along the cylinder connection portion. 3. A work machine according to claim 1 or 2, wherein the underside of the top plate of the fall prevention member is spaced a predetermined distance above the connecting bracket and the upper end of the cylinder. A work machine as described in any one of claims 1 to 3, characterized in that the edge of the top plate of the fall prevention member is provided with an anti-skid edge extending downwardly to prevent the top plate portion that has climbed up onto the connecting bracket and the upper end of the cylinder from coming off. The cylinder upper end of the hydraulic cylinder is pin-connected to the connecting bracket by a cylinder connecting pin,
A working machine as described in any one of claims 1 to 4, characterized in that at least a portion of the fall prevention member covers the axial side of the cylinder connecting pin at the upper end of the cylinder, and has a cylinder connecting pin insertion hole or notch in the portion through which the cylinder connecting pin is inserted.

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