JP2003074087A - Construction machine with operation room - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the car height, for example, when traveling on a road by lowering an operation room up to a lower position to a lowering position overhanging the front of a frame. SOLUTION: A link mechanism 10 composed of a front side parallel link 11 and a rear side parallel link 12 is arranged on a turning frame 4 of an upper turning body 2. The front side parallel link 11 joins a pin joining part 11D by a pin to the turning frame 4 in a lower side position more than a pin joining part 12B of the rear side parallel link 12. A lifting cylinder 14 is obliquely arranged between the parallel links 11 and 12, and the operation room 13 arranged above the link mechanism 10 is rotated between a lifting position and the lowering position by extending and contracting the lifting cylinder 14. A double cylinder body 18 for selectively regulating a rotational movement of the parallel links 11 and 12 in the lifting position and the lowering position is arranged between the turning frame 4 and the operation room 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction machine with a driver's cab, which is preferably used as a construction machine such as a hydraulic excavator, and is particularly provided with a lifting cylinder for raising and lowering the operator's cab on a swing frame. Concerning construction machinery with cab.

[0002]

2. Description of the Related Art Generally, construction machines such as hydraulic excavators are
It is composed of a lower traveling body and an upper revolving body which is provided on the lower traveling body so as to be rotatable. The upper revolving body has a frame having a skeleton structure, and a driver's cab or the like is provided on the frame. Has been.

In this type of conventional hydraulic excavator, a working device is provided on the front side of the upper swing body so that the working device can be lifted and lowered. By operating this working device, excavation work such as earth and sand is performed. ing.

By the way, this hydraulic excavator is also used as a construction machine for scrap work for loading and unloading scraps such as earth and sand, construction waste materials, and iron scraps on the loading platform of a truck, in addition to the excavation work described above. It is possible. However, when carrying out such scrap work, for example, if the operator's cab is located at a position lower than or about the same as the truck bed, the operator on board the operator's cab will load the truck higher. There is an inconvenience such as the scrap being made difficult to see.

Further, in Japanese Patent Laid-Open No. 3-72123 (hereinafter referred to as another conventional technique), an operator's cab is connected to a frame side of an upper swing body via a link mechanism, and this link mechanism is connected by a hydraulic cylinder. Disclosed is a hydraulic excavator that is configured to move up and down between an ascending position located above the frame and a descending position that extends forward by rotating the cab forward and backward.

Further, in the other prior art, during the above-mentioned scrap work, the hydraulic cylinder is reduced and the operator's cab is preliminarily rotated to the elevated position via the link mechanism, so that the operator can move from the operator's cab. It is possible to work while looking down on the loading platform, which makes the work more efficient.

On the other hand, when the hydraulic excavator is placed on the trailer and conveyed, the hydraulic cylinder is previously extended, and the operator's cab is rotated to the lowered position via the link mechanism, whereby the hydraulic excavator is moved. The height of the included trailer is kept within the specified height limit.

[0008]

By the way, in the hydraulic excavator according to the other prior art described above, the hydraulic cylinder for raising and lowering the operator's cab is disposed at the position rearward of the link mechanism and the link mechanism and the upper revolving structure. It is configured to be mounted between the frame and the frame.

Therefore, in the prior art, it is necessary to specially secure a mounting space for mounting the hydraulic cylinder on the frame located behind the operator's cab, for example, on the machine room side where the engine or the like is housed. As a result, there is a problem in that the frame structure of the entire upper revolving structure becomes complicated and the entire structure becomes large.

Further, in the above-mentioned other prior art, a hydraulic cylinder for raising and lowering the operator's cab is mounted between the link mechanism and the frame in a substantially horizontal position. Therefore, it is difficult to effectively raise and lower the operator's cab by effectively utilizing the driving force when the hydraulic cylinder expands and contracts, and there is a problem that the hydraulic cylinder itself needs to be increased in size.

Further, in another conventional technique, the link mechanism is composed of four parallel links provided at the front, rear, left and right between the cab and the frame. Then, when the cab is moved to the raised position, the cab is supported on the frame via four parallel links,
The driver's cab is attached to the frame in a stable position.

However, when the operator's cab is moved to the lowered position, the operator's cab is arranged so as to project from the frame to the front, and is substantially cantilevered with respect to the frame. When excavating or traveling on the road, the driver's cab is apt to vibrate up and down, and the riding comfort deteriorates.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention does not require a special mounting space for a lifting cylinder for moving up and down, and requires a simple frame structure. Can be made smaller and the entire size can be reduced, and the driving force from the lifting cylinder can be effectively used.
It is an object of the present invention to provide a construction machine with a driver's cab, which can raise and lower the driver's cab and downsize the lifting cylinder.

Another object of the present invention is to keep the cab in a stable state with respect to the frame when the cab is rotated to the lowered position or the raised position, for example, when traveling on the road. Another object of the present invention is to provide a construction machine with a cab that suppresses vibration of the cab and improves ride comfort.

[0015]

In order to solve the above-mentioned problems, a construction machine with a cab adopted by the invention of claim 1 has a frame forming a vehicle body, a front part on the frame,
A link mechanism composed of parallel links arranged in parallel with each other in a state of being separated in the rear direction, an operator's cab provided above the link mechanism, a front parallel link and a rear side of the link mechanism. The link mechanism is located between the parallel links, and the link mechanism is rotated forward and backward in response to expansion and contraction to raise the driver's cab to an upper position and to lower the driver's cab in front of the frame. And a lower end of each of the parallel links is pin-coupled to the frame at a position spaced apart from the front and rear of the frame, and a pin on the front side of each of the pin coupling portions is formed. The coupling portion is arranged at a position at least lower than the pin coupling portion on the rear side.

With this configuration, since the lifting cylinder is arranged between the front parallel link and the rear parallel link of the link mechanism, for example, the lifting cylinder is oriented to extend between the parallel links. When driven, the entire cab can be rotated to a raised position relative to the frame. Further, when the lifting cylinder is driven in the direction of contraction, the entire cab can be rotated to the lowered position in which it is extended forward with respect to the frame.

Since one end of the front parallel link of the parallel links is attached to the frame side at a position at least lower than the rear parallel link, the operator's cab is located in front of the frame. When rotated to the extended down position, the driver's cab can be lowered to a lower position, for example, the vehicle height when traveling on the road can be lowered, and excavation work in front of the vehicle or below the ground can be performed. When performing, the cab can be brought closer to the excavation work position.

Further, in the invention of claim 2, between the frame side and the driver's cab side, the operator's cab which is rotated together with the link mechanism to the lowered position by the lifting cylinder is held at the front position of the frame. The driver's cab holding means is provided.

With this configuration, when the operator's cab is rotated to the lowered position by the lifting cylinder,
The driver's cab can be stably held by the driver's cab holding means in a state of being projected to the front of the frame.

Further, in the invention of claim 3, the cab holding means is mounted between a fixed frame standing on the frame and between the cab side and the fixed frame to fix the cab. It is composed of a latching tool that is locked to the frame.

As a result, the driver's cab can be held in a hooked state by the hooks with respect to the fixed frame erected on the frame,
The load (weight) from the driver's cab received by the lifting cylinder can be reduced by the latch.

Further, in the invention of claim 4, between the parallel link on the front side and the parallel link on the rear side of the link mechanism,
By fixing the rotation of the link mechanism, a fixing means for selectively fixing the driver's cab to the raised position and the lowered position is provided.

With this configuration, the rotation of the link mechanism can be restricted by the fixing means in the lowered position of the driver's cab, so that the driver's cab in the state of being projected in front of the frame can be more stably fixed to the frame, Vibration in the cab can be suppressed to a low level. Further, even when the driver's cab is rotated to the raised position, the rotation of the link mechanism can be restricted by using the fixing means, so that the driver's cab can be fixed above the frame and deformation of the link mechanism can be suppressed. You can

According to a fifth aspect of the present invention, the fixing means is an expandable double cylindrical body arranged between a front parallel link and a rear parallel link of the link mechanism, The double cylinder body is provided with an ascending position fixing part for fixing the cab in the ascending position and a descending position fixing part for fixing the cab as the descending position.

Thus, at the raised position of the operator's cab, the rotation of the link mechanism can be restricted by the raised position fixing portion provided on the double cylinder. Further, at the lowered position of the operator's cab, the rotation of the link mechanism can be restricted by the lowered position fixing portion provided on the double cylinder.

Further, in the invention of claim 6, the elevating cylinder is obliquely arranged between the front parallel link and the rear parallel link.

Further, in the invention of claim 7, at least one of the parallel links is provided with a ladder for raising and lowering to the cab.

Thus, when the operator's cab is rotated to the elevated position located above the frame, the operator (operator) of the construction machine can easily get on and off the operator's cab by using the ladder for raising and lowering. can do.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a construction machine with a cab according to an embodiment of the present invention will be described in detail with reference to FIGS.

In the figure, 1 is a lower traveling body, 2 is a lower traveling body 1.
The upper revolving superstructure 2 provided so as to be revolvable above is shown. The upper revolving superstructure 2 includes a revolving frame 4 revolvably provided on the lower traveling structure 1 via a revolving device 3, and a revolving frame 4 on the revolving frame 4. A machine room 5 provided and accommodating an engine, a hydraulic pump (not shown), and the like, and a counterweight 6 provided on the rear side of the machine frame 5 at the rear side of the machine frame 5,
A driver's cab 13 which will be described later and is provided on the front side of the revolving frame 4.
Etc. At the center of the front part of the swing frame 4, as shown in FIG.
A work device 7 including a bucket 7C and the like is provided so as to be able to lift and lower.

As shown in FIG. 3, the turning frame 4 has a center frame 8 which is a central portion forming a connecting portion with the turning device 3, and a boom 7A of the working device 7 is pinned on the front end side of the center frame 8. The bracket 8A to be joined is integrally provided. Then, in the center frame 8,
A link mounting frame 9 to which a link mechanism 10 described later is mounted is integrally provided at the left side position of the bracket 8A.

Here, as shown in FIGS. 3 to 5, the link mounting frame 9 includes a side beam portion 9A extending along the front and rear directions of the upper swing body 2, a front end side of the side beam portion 9A, and a center. Front beam 9B connecting left and right with the frame 8
And a rear beam portion (not shown) that connects the rear end side of the side beam portion 9A and the center frame 8 in the left and right directions.

On the front end side of the link mounting frame 9, a pair of front brackets 9C, 9C are provided at the left and right ends of the front beam portion 9B, and each front bracket 9C is provided.
Protrudes substantially horizontally from the link mounting frame 9. The side beam portion 9A and the rear beam portion of the link mounting frame 9 are
A pair of left and right rear brackets 9D (only one is shown) are provided at positions rearward of the front brackets 9C,
The rear bracket 9D projects upward from the link mounting frame 9.

Reference numeral 10 denotes a link mechanism provided on the link mounting frame 9 of the revolving frame 4.
As shown in FIGS. 3 and 4, one end (lower end) side is pin-connected to the front bracket 9C of the link mounting frame 9, and the other end (upper end) side is pin-connected to a front bracket 13B of the cab 13 described later. Parallel links 11,1
1 and a rear parallel link 12 (only one of which is shown) whose one end is pin-connected to the rear bracket 9D and the other end is pin-connected to the rear bracket 13C of the cab 13. The parallel links 11 and 12 are arranged on the link mounting frame 9 in parallel with each other while being separated in the front and rear directions.

Further, each front parallel link 11 has a structure shown in FIG.
As shown in FIG. 7, a plurality of reinforcing beams 11A, 11A, ..., which are arranged so as to be spaced apart from each other in the upper and lower directions and integrally connect these parallel links 11 in the left and right directions, and between these reinforcing beams 11A. Other reinforcing beams 11B and 11B that are positioned and integrally connect the parallel links 11 in an oblique direction are provided. Further, each parallel link 11 is integrally formed with a bracket 11C located on the upper end side thereof for a double cylinder 18 to be described later.

A reinforcing beam (not shown) similar to the reinforcing beams 11A and 11B is also provided between the rear parallel links 12, and the parallel link 12 is located at the lower end side thereof. Another bracket 12A for the heavy cylinder 18 is integrally formed.

Here, among the pin coupling portions 11D and 12B located on one end (lower end) side of the parallel links 11 and 12,
The pin coupling portion 11D formed by the front bracket 9C is connected to the pin coupling portion 12B formed by the rear bracket 9D as shown in FIG.
It is arranged at a position lower than that by a dimension h.

Reference numeral 13 denotes a driver's cab provided on the link mounting frame 9 of the swivel frame 4. The driver's cab 13 is formed as a box-shaped cab box having a floor plate portion 13A, and a front side of the floor plate portion 13A is provided. A pair of front brackets 13B, 13B are integrally formed so as to be separated left and right. Further, a pair of rear brackets 13C (only one is shown) are integrally formed on the rear side of the floor plate portion 13A so as to be spaced apart left and right.

The driver's cab 13 has the front bracket 1
3B is rotatably connected to the upper end of the parallel link 11,
The rear bracket 13C is rotatably connected to the upper end side of the parallel link 12 to be mounted on the upper portion of the link mechanism 10.

Reference numeral 14 denotes an elevating cylinder (only one is shown) provided between the swivel frame 4 and the operator's cab 13 so as to be spaced apart left and right, and the elevating cylinder 14 is a tube 14A.
And a rod 14B that expands and contracts from the tube 14A. Then, the tube 1 of the lifting cylinder 14
4A has a bottom side pin-connected to the side beam portion 9A side of the revolving frame 4 via a bracket (not shown) or the like, and the rod 1
The front end side of 4B is pin-connected to the rear bracket 13C side of the cab 13 together with the parallel link 12 of the link mechanism 10.

Here, the lifting cylinder 14 is arranged between the parallel links 11 and 12 of the link mechanism 10 in an inclined state as shown in FIG. Then, the lifting cylinder 14 moves the rod 14B by the pressure oil supplied and discharged from the outside.
By extending from the tube 14A, the parallel links 11 and 12 of the link mechanism 10 are rotated rearward, and the driver's cab 13 is moved to the raised position located above the revolving frame 4 as shown in FIGS. 2 to 4. It is structured to lead.

Further, the lifting cylinder 14 includes a rod 14B.
Shrinks into the tube 14A to rotate the parallel links 11 and 12 of the link mechanism 10 in the forward direction, and the cab 13 is extended forward from the revolving frame 4 as shown in FIGS. 1 and 5. It is configured to lead to the lowered position.

Reference numeral 15 denotes a mooring device (only one of which is shown) as a cab holding means provided between the link mounting frame 9 of the swivel frame 4 and the cab 13 so as to be spaced apart left and right.
The mooring device 15 is composed of a fixed frame 16 and a pendant rope 17, which will be described later, and holds the cab 13 in the lowered position when the cab 13 is rotated by the elevating cylinder 14 together with the link mechanism 10 to the lowered position. Positioning is performed in the (moored) state.

Reference numeral 16 denotes a fixed frame which is erected on the link mounting frame 9 of the turning frame 4. This fixed frame 16 is shown in FIG.
As shown in FIG. 4 and FIG. 4, the lower end side is fixed to the side beam part 9A side of the link mounting frame 9 at a position near the rear bracket 9D, and the upper end side is vertically extended.
Pendant rope 17 integrally provided on the upper end side of 6A
And a slanting beam portion 16C having a lower end fixed to the front end side of the side beam portion 9A and an upper end side extending obliquely upward toward the mounting plate portion 16B.
The upper end side of C is attached to a mounting plate portion 16B integrated with the upper end side of the column portion 16A.

The fixed frame 16 is formed by the support 16
A configuration is formed as a beam structure having a triangular shape from A, the mounting plate portion 16B, and the inclined beam portion 16C, and the cab 13 is moored and held at a lowered position with respect to the revolving frame 4 via the pendant rope 17. Has become.

Reference numeral 17 denotes a pendant rope which is detachably provided between the operator's cab 13 and the fixed frame 16 and serves as a hooking tool. The pendant rope 17 has a fixed frame 16 at one end.
Is attached to the mounting plate portion 16B of the vehicle, and the other end thereof is attached to the rear bracket 13C of the cab 13. The pendant rope 17 is attached to the mounting plate portion 16B of the fixed frame 16 and the cab 1 when the cab 13 is rotated to the lowered position.
By being pulled between 3 and 3, a tensile force is applied obliquely upward to the cab 13, and the cab 13 that extends forward from the revolving frame 4 is held in a hooked state with respect to the revolving frame 4. It is composed.

Reference numeral 18 denotes a pair of double cylinders (only one of which is shown) constituting fixing means provided between the front parallel links 11 and the rear parallel links 12 of the link mechanism 10. As shown in FIGS. 4 and 5, the double cylinder 18 has an inner cylinder 19 whose one end side is pin-connected to the bracket 12A of the parallel link 12, and one end side which is slidably inserted into the outer peripheral side of the inner cylinder 19. The other end side is composed of an outer cylinder 20 pin-connected to the bracket 11C of the parallel link 11. The inner cylinder 19 and the outer cylinder 20 are obliquely arranged between the front parallel link 11 and the rear parallel link 12 so as to intersect the elevating cylinder 14.

Here, as shown in FIGS. 4 and 5, the inner cylinder 19 has pin holes 19A and 19A formed at one end thereof, and other pin holes 19B and 19B formed at the other end thereof. ing. Further, the pin hole 2 is also provided on one end side of the outer cylinder 20.
0A and 20A are formed.

When the operator's cab 13 is guided to the raised position, the inner cylinder 19 is contracted into the outer cylinder 20, and the fixing pins 21, 21 are fitted into the pin holes 19A, 20A in this state, The inner cylinder 19 and the outer cylinder 20 are restricted from sliding with each other, and the parallel links 11 and 12 are restricted from rotating. That is, the pin holes 19A and 20A and the fixing pin 21 constitute a raised position fixing portion that fixes the cab 13 at the raised position.

When the operator's cab 13 is guided to the lowered position, the inner cylinder 19 extends from the outer cylinder 20, and in this state, the fixing pins 21 and 21 are fitted into the pin holes 19B and 20A, respectively. The mutual sliding of the cylinder 19 and the outer cylinder 20 is restricted, and the rotation of the parallel links 11, 12 is restricted. That is, the pin holes 19B and 20A and the fixing pin 2
Reference numeral 1 constitutes a descending position fixing portion for fixing the cab 13 in the descending position.

Reference numeral 22 is a ladder provided between the revolving frame 4 and the operator's cab 13 and provided between the front parallel links 11. The ladder 22 is provided when the operator's cab 13 is rotated to the raised position. It is configured to stand upright together with the parallel link 11, and the operator climbs up and down to the cab 13 during work.

Further, 23 is a frame-side step provided near the lower end side of the ladder 22 and provided on the side beam portion 9A side of the revolving frame 4, and 24 is near the upper end side of the ladder 22 of the cab 13. The operation room side step provided in the floor board part 13A side is shown.

The hydraulic excavator according to the present embodiment has the above-mentioned structure, and its operation will be described below.

First, when excavating earth and sand with the work device 7, as shown in FIGS. 1 and 5, the pendant rope 17 of the mooring device 15 is previously hooked between the operator cab 13 and the fixed frame 16. In addition, each fixing pin 21 is detached from the double cylinder 18, and in this state, a switch (not shown) provided by the operator on the upper swing body 2 side, for example.
The lifting cylinder 14 is contracted by remote-controlling the above.

As a result, the parallel links 11 and 12 of the link mechanism 10 provided between the revolving frame 4 and the cab 13 are provided.
Is rotated toward the front side of the revolving frame 4, and the double cylindrical body 18 extends between the parallel links 11 and 12. Accordingly, the operator cab 13 is extended forward from the revolving frame 4. Can be brought to a lowered position.

When working in front of the cab 13, for example, the entire cab 13 can be brought closer to the front side of the bucket 7C of the working device 7, and the view from the cab 13 to the work site by the bucket 7C can be reduced. Can be well secured, and workability during excavation work can be improved.

Here, on the link mounting frame 9 of the revolving frame 4, the front parallel links 11 of the link mechanism 10 are mounted on the front bracket 9C.
1D, rear parallel links 12 are rear bracket 9D
Since it is arranged at a position lower than the pin coupling portion 12B attached to the driver's cab, the operator's cab 13 is rotated when the operator's cab 13 is rotated to the lowered position which extends forward.
Can be lowered to a position lower than the other prior arts described above, and the vehicle height of the hydraulic excavator including the cab 13 can be lowered. Thereby, for example, even when excavation work is performed under the ground, the cab 13 can be brought closer to the bucket 7C side, and workability can be improved.

On the other hand, when the undercarriage 1 travels on the road or when the hydraulic excavator is placed on a trailer (not shown) and conveyed, the cab 13 is linked to the cab 13 in the same manner as during excavation work. It is made to rotate to the lowered position via 10, etc. Then, at this time, the vehicle height of the hydraulic excavator can be kept low within the prescribed height limit for the reason described above.

When the driver's cab 13 is rotated to the lowered position as described above, the pendant rope 17 is moved to the driver's cab 1
3 is strongly pulled between the fixed frame 16 and the fixed frame 16, so that a diagonal upward pulling force from the pendant rope 17 can be applied to the operator's cab 13, and the lifting cylinder 14 and the pendant rope 17 can be connected to each other. Cab 1 in both
3 can be held and positioned in the lowered position that extends forward from the revolving frame 4.

At this time, by mounting the fixing pin 21 in each of the pin holes 19B and 20A of the double cylinder 18, the rotation of the link mechanism 10 is restricted by the double cylinder 18 in the lowered position of the cab 13. can do.

Thus, in the present embodiment, when excavating or traveling on the road, the operator's cab 13 in the state of being extended in front of the revolving frame 4 is fixed to the mooring device 15 and the double cylinder 18.
With this, it is possible to stabilize and fix the vehicle to the revolving frame 4, and it is possible to suppress the vibration of the cab 13 and enhance the riding comfort. And during such excavation work,
The weight of the operator's cab 13 side and the like are lifted by the lifting cylinder 14 and the mooring device 1.
5 and the double cylinder 18 can be distributed and supported, respectively, and the load on the elevating cylinder 14 at the lowered position of the cab 13 can be reduced.

On the other hand, as shown in FIG. 2, when scraps such as earth and sand, waste materials for construction, or iron scraps are piled up and down on the loading platform 25A of the truck 25 (hereinafter referred to as scrap work), the pendant rope is used in advance. 17 is removed and each fixing pin 21 is detached from the double cylinder 18, and the elevating cylinder 14 is extended in this state.

As a result, the parallel link 1 of the link mechanism 10
When the double cylinders 18 are contracted between the parallel links 11 and 12, the rear cylinders 1 and 12 are rotated rearward, and accordingly, the operator's cab 13 is moved from the lowered position to above the revolving frame 4. It can lead to a raised position.

At this time, the fixing pin 21 is attached to each of the pin holes 19A and 20A of the double cylinder 18 to restrict the rotation of the link mechanism 10 in the raised position of the operator's cab 13 as in the lowered position. Can and swivel frame 4
The double cylinder 18 can prevent the driver's cab 13 from vibrating above the link mechanism 10 via the link mechanism 10.

Moreover, the lifting cylinder 14 and the double cylinder 18
Since the parallel links 11 and 12 of the link mechanism 10 are arranged so as to intersect each other, the lifting cylinder 14 and the double cylinder 18 are used as a reinforcing member for the link mechanism 10. Link mechanism 1
The strength of 0 can be increased.

Therefore, according to the present embodiment, even when performing scrap work or the like, the vibration of the cab 13 can be suppressed to a small level in the same manner as the above-mentioned excavation work, and the operator can move from the cab 13 to the truck 25. It is possible to work stably with the loading platform 25A looking down from above.
The overall workability can be improved.

Also, the tube 14A of the lifting cylinder 14
Is attached to the side beam portion 9A side of the swing frame 4, and the rod 14
By mounting B on the floor plate portion 13A side of the cab 13, the lifting cylinder 14 is housed between the parallel links 11 and 12, so there is no need to specially provide a mounting space for the lifting cylinder 14 on the revolving frame 4. By simplifying the frame structure, the hydraulic excavator can be downsized.

Further, since the elevating cylinder 14 is arranged so as to be inclined between the parallel links 11 and 12, the elevating cylinder 14 operates when rotating the operator's cab 13 from the lowered position to the raised position. A driving force that lifts the chamber 13 upward can be generated, and the lifting cylinder 14
It is possible to effectively utilize the driving force of the driving cab 13 to rotate the cab 13 to the raised position, and to efficiently transmit the driving force of the lifting cylinder 14 to the cab 13 side, thereby reducing the size of the lifting cylinder 14. You can

Furthermore, since the operator's cab 13 is rotated to the raised position when the lifting cylinder 14 is extended,
Due to the pressure receiving area of a cylinder (not shown) sliding in the tube 14A, the hydraulic driving force when the elevating cylinder 14 is extended can be increased compared to when the elevating cylinder 14 is reduced, and the lifting cylinder 14 lifts the cab 13. Can be stabilized.

In the above embodiment, the front parallel link 11 and the rear parallel link 12 are provided between the revolving frame 4 and the operator's cab 13 at positions separated from each other in the front and rear. However, instead of this, for example, one or a plurality of other parallel links may be provided between the parallel links 11 and 12.

Further, in the above embodiment, the elevating cylinder 14 is described as arranged between the parallel links 11 and 12, but the present invention is not limited to this. For example, the elevating cylinder 1
The tube 14A side of No. 4 may be provided on the machine room 5 side of the upper swing body 2 as in the above-described other conventional techniques. Even in this case, when the cab 13 is rotated between the ascending position and the descending position, the vibration and the like of the cab 13 can be sufficiently suppressed by the mooring device 15 and the double cylinder 18.

Further, in the above embodiment, the inner cylinder 19 is attached to the parallel link 12 and the outer cylinder 20 of the double cylinder 18 is attached to the parallel link 11.
Instead, for example, the inner cylinder 19 may be mounted on the link mounting frame 9 side of the swivel frame 4, or the outer cylinder 20 may be mounted on the floor plate portion 13A side of the operator's cab 13.

Further, in the above embodiment, the double cylinder 18
The inner cylinder 19 is provided with pin holes 19A and 19A at one end side thereof and pin holes 19B and 19B at the other end side thereof to selectively fix the cab 13 to the ascending position and the descending position. As mentioned above, instead of this, the inner cylinder 19 has
In addition to the pin holes 19A and 19B, an intermediate pin hole may be provided at an intermediate position between the pin hole 19A on the one end side and the pin hole 19B on the other end side. Then, in this case, by mounting the fixing pin 21 in the intermediate pin hole and the pin hole 20A of the outer cylinder 20, the operator's cab 13 can be fixed at a predetermined intermediate position, and the operator's cab 13 can be fixed according to the work content. 1
The height of 3 can be adjusted.

Further, in the above embodiment, the bucket 7
The hydraulic excavator with the C attached has been described as an example, but instead of the bucket 7C, a gripper such as a grapple, a crusher for dismantling, various attachments such as a lifting magnet for scrap transportation may be attached, Further, it can be widely applied to other construction machines such as hydraulic cranes and wheel loaders.

[0075]

As described above in detail, according to the first aspect of the present invention, the link mechanism is constituted by the parallel links which are arranged in parallel with each other in the front and rear directions on the frame. An elevating cylinder is arranged between each parallel link of the link mechanism, and the operator's cab provided at the upper part of the link mechanism is moved up and down between the ascending position and the descending position by the elevating cylinder. Since one end side of the parallel link is configured to be attached to the frame side at a position at least lower than the rear parallel link, the lifting cylinder can be housed between the parallel links of the link mechanism,
There is no need to specially provide a mounting space for the lifting cylinder on the frame, so that the frame structure can be simplified and the construction machine as a whole can be downsized.

Of the parallel links, the front parallel link has one end attached to the frame side at a position at least lower than the rear parallel link, so that the driver's cab is located in front of the frame. The driver's cab can be lowered to a lower position when the vehicle is rotated to the extended descending position, and for example, the vehicle height when traveling on the road can be kept low within a prescribed height limit. Further, when performing excavation work in front of the vehicle or below the ground, the driver's cab can be brought closer to the excavation work position, and workability can be improved.

According to the second aspect of the present invention, the driver's cab holding means is provided between the frame side and the driver's cab side, and the driver's cab rotated by the elevating cylinder to the lowered position together with the link mechanism is located in front of the frame. Since it is configured to be held in the overhanging position, the driver's cab that is substantially cantilevered by the link mechanism etc. at the lowered position can be held in a stable state with respect to the frame, for example, while traveling. Further, it is possible to suppress a large vibration of the driver's cab and improve the riding comfort of the vehicle. Further, it is possible to prevent the weight and the like on the driver's cab side from being continuously added to the lift cylinder when the vehicle is traveling, etc., and it is possible to reliably reduce the load on the lift cylinder in the lowered position of the driver's cab.

Further, according to the third aspect of the invention, the cab holding means is composed of a fixed frame standing on the frame and a latch for locking the cab to the fixed frame. , The driver's cab can be held in a latched state by the latching device against the fixed frame erected on the frame, and the load (weight) from the driver's cab side received by the lifting cylinder can be reduced by the latching device. Therefore, the life of the lifting cylinder can be extended.

Furthermore, in the invention described in claim 4,
Since the fixing means is provided between the parallel links of the link mechanism and the fixing means restricts the rotation of the link mechanism, the cab is selectively fixed to the ascending position and the descending position. When the vehicle is rotated to the lowered position, the driver's cab can be held in a more stable state with respect to the frame by the driver's cab holding means and the fixing means, and vibration of the driver's cab when the vehicle is traveling can be suppressed. Further, even when the cab is rotated to the raised position, the rotation of the link mechanism can be restricted by the fixing means, and the fixing means can prevent the cab from vibrating above the frame via the link mechanism. it can.

On the other hand, in the invention described in claim 5, the fixing means is composed of a double cylindrical body which is provided between the front parallel link and the rear parallel link of the link mechanism so as to be expandable and contractible. Since the heavy cylinder is provided with the ascending position fixing part and the descending position fixing part, the operator's cab is raised while the double cylinder is expanded and contracted between the front parallel link and the rear parallel link. It can be selectively fixed to the position and the lowered position, and the fixing means can be easily configured by these double cylinders, the raised position fixing portion and the lowered position fixing portion.

Further, in the invention according to claim 6, since the elevating cylinder is arranged obliquely between the front parallel link and the rear parallel link, the cab is moved from the lowered position to the raised position. When rotating with, the lifting cylinder can generate a driving force that lifts the cab upward,
The driving force from the lifting cylinder can be effectively used to rotate the driver's cab to the raised position, and the driving force from the lifting cylinder can be efficiently transmitted to the driver's cab side, which enables downsizing of the lifting cylinder. Become.

Further, according to the invention described in claim 7, since at least one of the parallel links is provided with a ladder for raising and lowering to the cab, the cab located above the frame is raised. When rotated to the position,
The operator (operator) of the construction machine can easily get on and off the operator's cab by using the ladder for raising and lowering, so that the safety of the driver can be secured.

[Brief description of drawings]

FIG. 1 is an overall view showing a state in which a driver's cab of a hydraulic excavator according to an embodiment of the present invention is rotated to a lowered position.

FIG. 2 is an overall view showing a state in which a driver's cab of the hydraulic excavator according to the embodiment of the present invention is rotated to a raised position.

3 is an enlarged front view showing the hydraulic excavator in FIG. 2. FIG.

FIG. 4 is an enlarged view of essential parts showing a link mechanism, a mooring device, a double cylinder body and the like in FIG.

5 is an enlarged view of essential parts showing a link mechanism, a mooring device, a double cylinder body and the like in FIG. 1. FIG.

[Explanation of symbols]

4 swivel frames 10 link mechanism 11,12 parallel links 11D Pin connection part on the front side 12B Rear side pin coupling part 13 Driver's cab 14 Lifting cylinder 15 Mooring device (driver's cab holding means) 16 fixed frame 17 Pendant rope (hook stopper) 18 Double cylinder (fixing means) 19A pin hole (upward position fixing part) 19B pin hole (lowering position fixing part) 20A pin hole 21 fixing pin 22 ladders

Claims (7)

[Claims] 1. A frame forming a vehicle body, a link mechanism including parallel links arranged in parallel with each other in the front and rear directions on the frame, and provided at an upper portion of the link mechanism. The operator's cab and the parallel link on the front side and the parallel link on the rear side of the link mechanism. The link mechanism is rotated forward and backward in response to expansion and contraction. It comprises an elevating cylinder for elevating the operator's cab between an ascending position located above and a descending position projecting to the front of the frame, and the lower end side of each parallel link is at a position spaced apart in front of and behind the frame. A construction machine with a cab configured to be pin-coupled to a frame, and a front pin coupling portion of each of the pin coupling portions is arranged at a position at least lower than a rear pin coupling portion. 2. Between the frame side and the cab side,
The construction machine with a driver's cab according to claim 1, wherein a driver's cab holding means for holding the driver's cab, which has been rotated together with the link mechanism by the lifting cylinder with the link mechanism, at a front position of the frame is provided. 3. The cab holding means is mounted between a fixed frame provided upright on the frame and between the cab side and the fixed frame, and locks the cab with respect to the fixed frame. The construction machine with a cab according to claim 2, wherein the construction machine comprises a latch. 4. Between the front parallel link and the rear parallel link of the link mechanism, by restricting the rotation of the link mechanism, the driver's cab can be selectively moved to an ascending position and a descending position. The construction machine with a cab according to claim 1, wherein the fixing means for fixing the construction machine to the vehicle is provided. 5. The fixing means comprises an expandable / contractible double cylinder disposed between a front parallel link and a rear parallel link of the link mechanism. The construction machine with a cab according to claim 4, wherein a rising position fixing part for fixing the cab in a rising position and a descending position fixing part for fixing the cab in a descending position are provided. 6. The construction machine with a driver's cab according to claim 1, 2, 3, 4, or 5, wherein the elevating cylinder is obliquely arranged between the front parallel link and the rear parallel link. . 7. The operation according to claim 1, 2, 3, 4, 5 or 6, wherein at least one of the parallel links is provided with a ladder for raising and lowering to the cab. Construction machinery with room.