JP2012162932A - Guard structure for operator's cab glass of construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a guard structure for operator's cab glass of a construction machine, which allows an operator to perform maintenance of the front glass of an operator's cab at ease with a reduced psychological load resulting from the high-place work.SOLUTION: The lower end of a lower guard 10 which covers a lower glass 7 of an operator's cab 5 is tiltably connected adjacent to the operator's cab 5 with a pin 12. An upper guard 9 which covers an upper glass 6 of the operator's cab 5 is relatively rotatably connected to the upper part of the lower guard 10. The upper part of the upper guard 9 is connected adjacent to the operator's cab 5 through an interlocking arm 16. The interlocking arm 16 is rotated in concert with tilting of the lower guard 10, so that the upper guard 9 is moved. The lower guard 10 is kept on the level by a stopper member 13 for use as a foothold for an operator, while the upper guard 9 is kept approximately upright at a position apart from the operator's cab 5 in the forward direction.

Description

  The present invention relates to a guard structure for protecting a driver's cab glass and an operator from rocks and debris flying into a driver's cab of a construction machine such as a hydraulic excavator.

For construction machines such as hydraulic excavators, measures to install a front guard made of wire mesh, for example, on the front side of the front glass to protect the operator's cabin glass and the operator's operator from rocks flying from the front during work. Has been taken. Especially in construction machines that perform breaker operations (crushing operations), a large number of debris such as concrete and bedrock that are to be crushed scatter, making the front guard a necessity.
The front guard is very effective for protecting the driver's cab, but it is necessary to remove the front guard when performing maintenance such as wiping and cleaning the front glass and replacing the wiper blade. Various proposals have been made to efficiently carry out such maintenance work. For example, in the technique described in Patent Document 1, the front guard is divided into two parts in the vertical direction and connected to each other with a hinge, and one of the front guards is overlapped on the other front guard with the hinge as the center. It is exposed to allow maintenance.

However, the technique of Patent Document 1 facilitates the operation for exposing the front glass as compared with the case where the front glass is fixed with a bolt or the like, but does not improve the efficiency of the entire maintenance work. In other words, the cab of this type of construction machine is often installed in a very high place for reasons such as ensuring the visibility of the vehicle or the operator, and there are differences depending on the size of the vehicle body. In many cases, the room is located at a height as high as a person's height because it is installed on the upper revolving unit. For this reason, when the front glass of the cab is maintained, a work different from the original maintenance work of preparing a scaffold or the like in advance has occurred.
As a countermeasure for such a problem, for example, in the technique of Patent Document 2, a front guard is used as a scaffold when maintaining the front glass. In this technology, a front guard is provided at the lower part of the front glass where the scattering of debris is concentrated especially during breaker work.Maintenance is achieved by tilting the front guard to a horizontal position around the lower end and holding it with a stopper. It functions as a scaffold for workers at the time.

JP-A-9-228422 JP-A-10-147756

With the technique of the above-mentioned Patent Document 2, maintenance of the front glass is easy by having an operator or the like wrap around the front guard held horizontally from the operator's cab door without the need for preparing a scaffolding in advance. Therefore, it is a very effective measure in terms of work efficiency. However, since the work is performed on the front guard located at a high place, it becomes a work that is very tense for an operator who particularly dislikes the high place. For this reason, there has been a demand for measures that can reduce the psychological burden on the operator and can perform maintenance of the front glass with peace of mind.
The present invention has been made to solve such problems, and the object of the present invention is to reduce the psychological burden on the operator caused by work at a high place and to reduce the front glass of the cab. It is to provide a guard structure for the cab of a construction machine that can be maintained with peace of mind.

  In order to achieve the above-mentioned object, the invention of claim 1 is directed to a guard structure for a cab glass of a construction machine in which a guard that covers the front glass and protects the front glass is provided in front of the front glass of the cab. The lower end of the cab is tiltably connected to the lower part of the cab, and a protective position that covers the lower part of the front glass, and an open position that is held in a substantially horizontal posture by the holding means and exposes the lower part of the front glass to the front. The lower guard, which is switched by tilting around the lower end, is connected to the upper end of the lower guard so that it can rotate relative to the upper guard, and the upper part is connected to the cab side via an interlocking arm. Centering on the cab side as the lower guard tilts, between the protective position covering the upper part and the open position where the upper part of the windshield is exposed forward by separating the front glass from the cab in a substantially upright position And upper guard to be switched while the turning arm is rotated, in which a locking means for securing the upper guard and lower guard protection position.

According to a second aspect of the present invention, there is provided the assist means according to the first aspect, wherein one end is connected to the cab side and the other end is connected to the interlocking arm, and the upper guard is always urged to the protective position side via the interlocking arm. It is provided.
According to a third aspect of the present invention, in the first or second aspect, the locking means is provided on both the left and right sides of the front upper portion of the cab, and is installed in the left-right direction on a pair of lock brackets each having a lock hole and the upper guard. And a slide lock bar that slides with an operating portion provided at one end, and allows the pair of lock pins to be inserted into and removed from the lock holes of the lock bracket when the upper guard is in the protective position. And an urging means for urging the slide lock bar in a direction in which the pin is inserted into the lock hole.
According to a fourth aspect of the present invention, in the first to third aspects, the upper guard and the lower guard comprise a frame-like frame corresponding to the upper or lower portion of the front glass, and a lattice material arranged vertically and horizontally in the frame. It has been done.
According to a fifth aspect of the present invention, in the first to fourth aspects, a handle is provided on one side of the upper guard.

As described above, according to the guard structure for the cab glass of the construction machine according to the first aspect of the present invention, the upper guard and the lower guard are interlocked with each other so as to be switched between the protective position and the open position. In this case, the lower guard is held in a substantially horizontal posture by the holding means and used as a scaffold for the operator, while the upper guard is separated from the operator's cab in a substantially upright posture. Therefore, the worker can recognize that the upper guard prevents falling and relieve the tension caused by work at high places, and can perform maintenance on the lower guard with peace of mind by reducing the psychological burden. it can.
According to the guard structure for the cab glass of the construction machine according to the second aspect of the invention, in addition to the first aspect, the upper guard is always urged to the protection position side by the assist means, so that it is gradually switched to the open position. And can be switched to the protective position without requiring a large operating force.

According to the guard structure for the cab glass of the construction machine according to the invention of claim 3, in addition to claim 1 or 2, the slide lock bar provided on the upper guard is urged by the urging means, and the lock pin is While being inserted into the lock hole of the lock bracket provided in the operator's cab, the lock pin is detached from the lock hole by sliding the slide lock bar with the operation portion against the urging force of the urging means. Therefore, it is possible to hold the upper guard and the lower guard at the protection position and to switch to the open position only by operating the operation unit.
According to the guard structure of the cab glass of the construction machine according to the fourth aspect of the invention, in addition to the first to third aspects, since the lattice members are arranged vertically and horizontally in the frame-like frame, the upper guard and the lower guard are easily provided. Can be produced.
According to the guard structure of the cab glass of the construction machine according to the fifth aspect of the present invention, in addition to the first to fourth aspects, since the handle is provided on one side of the upper guard, the handle is gripped to protect the upper and lower guards. It is possible to switch between a position and an open position.

1 is an overall configuration diagram illustrating a hydraulic excavator to which a guard structure of an embodiment is applied. It is a left view which shows a driver's cab when an upper stage and a lower stage guard are made into an open position. It is a right view which shows a driver's cab when an upper stage and a lower stage guard are made into a protection position. It is a front view of the cab corresponding to FIG. It is a right view which shows a driver's cab when an upper stage and a lower stage guard are made into an open position. It is a front view of the cab corresponding to FIG. FIG. 6 is a detailed view of a lower guard corresponding to FIG. 5. It is the VIII-VIII sectional view taken on the line of FIG. 4 which shows the detail of a slide lock bar. It is a perspective view which shows the detail of the slide lock bar seen from the arrow X direction of FIG.

Hereinafter, an embodiment in which the present invention is embodied in a guard structure for a front glass provided in a cab of a hydraulic excavator will be described.
FIG. 1 is an overall configuration diagram showing a hydraulic excavator to which the guard structure of the present embodiment is applied, and FIG. 2 is a left side view showing a driver's cab when the upper and lower guards are in an open position.
On the lower traveling body 2 provided with the crawler 1, an upper revolving body 3 is provided so as to be able to turn, and the upper revolving body 3 is provided with a work machine 4 and a cab 5. The work machine 4 includes a boom, an arm, a bucket, and the like, and is operated by a hydraulic cylinder. The cab 5 is provided with a door 5a for getting on and off on the left side, and an operator boarding the cab 5 operates the traveling of the lower traveling body 1, the turning of the upper revolving body 2, the operation of the working machine 4, and the like.

A square upper glass 6 and a lower glass 7 are disposed on the front surface of the cab 5 as front glass, and an operator can visually recognize the front and surroundings from within the cab 5 through these. One side of the upper glass 6 is equipped with a wiper 8 used during rainy weather work. An upper guard 9 is disposed in front of the upper glass 6, and a lower guard 10 is disposed in front of the lower glass 7, so that the upper and lower glasses 6, 7 are respectively covered from the front.
The upper and lower guards 9 and 10 are manufactured by arranging a large number of grid members 9b and 10b vertically and horizontally in square frames 9a and 10a, respectively, and appropriately welding them. In addition to enabling visual recognition through the front 7, a function of protecting the upper and lower glass 6 and 7 from rocks and broken pieces flying from the front. Hereinafter, the posture of the upper and lower guards 9 and 10 when the upper and lower glass 6 and 7 are covered in this way is referred to as a protective position. Although details will be described later, the upper and lower guards 9 and 10 can be switched to positions where the upper and lower glass 6 and 7 are exposed to the front because of maintenance considerations. The posture of the guards 9 and 10 is referred to as an open position.

The configurations of the upper and lower guards 9 and 10 are not limited to the above. For example, a wire net may be stretched in the frames 9a and 10a, or a transparent synthetic resin plate may be stretched.
3 is a right side view showing the cab 5 when the upper and lower guards 9 and 10 are in the protective position, FIG. 4 is a front view of the cab 5 corresponding to FIG. 3, and FIG. FIG. 6 is a front view of the cab 5 corresponding to FIG. 5, and FIG. 7 is a detailed view of the lower guard 10 corresponding to FIG. 5.

As shown in FIGS. 3 and 4, the left and right sides of the lower part of the lower guard 10 are respectively connected to the left and right sides of the lower part of the cab 5 via pins 12, and forward from the protection position of the lower guard 10 centered on the pins 12. Tilt downward is allowed (indicated by arrow A in FIG. 3). As shown in FIG. 7, a rubber stopper member 13 (holding means) is attached to the lower end surface of the lower guard 10, and when the tilted lower guard 10 is in a horizontal position, the stopper member 13 is attached to the frame 5 b of the cab 5. It abuts and regulates the tilting of the lower guard 10. Thereby, the lower guard 10 is switched to the open position shown in FIGS. 5-7, and the lower glass 7 is exposed ahead.
Both the left and right sides of the upper part of the lower guard 10 are connected to the left and right sides of the lower part of the upper guard 9 via pins 14, respectively, and relative rotation of the guards 9 and 10 around the pin 14 is allowed. One end of the interlocking arm 16 is connected to the upper right side of the upper guard 9 by a pin 15, and the other end of the interlocking arm 16 is connected to the front right side of the cab 5 by a pin 17.

For this reason, when the lower guard 10 tilts forward and obliquely downward from the protection position to the open position as described above, the lower part of the upper guard 9 moves following this, while the upper part of the upper guard 9 has the other end It moves along an arcuate locus while rotating the interlocking arm 16 around the pin 17 on the side (cab 5 side) (indicated by an arrow B in FIG. 3). By interlocking with the lower guard 10 as described above, the upper guard 9 is separated forward from the cab 5 and switched to the open position shown in FIGS. 5 and 6, and the upper glass 6 is exposed forward. The lower guard 10 in the open position is held in a horizontal posture, and the upper guard 9 in the open position is held in a substantially upright posture while being separated from the cab 5.
Further, when the lower guard 10 is tilted from the open position to the protective position, the lower part of the upper guard 9 moves following this, while the upper part of the upper guard 9 is arcuate while rotating the interlocking arm 16. The upper guard 9 is switched to the protection position and covers the upper glass 6.

On the upper part of the upper guard 9, a slide lock bar 19 (locking means) for holding the upper and lower guards 9, 10 in the protective position is disposed. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 4 showing the details of the slide lock bar 19, and FIG. 9 is a perspective view similarly seen from the arrow X direction in FIG.
The slide lock bar 19 is installed to extend in the left-right direction on the upper rear surface (cab side 5) of the upper guard 9, and is inserted into the square holes 20a of the guide bracket 20 welded to the left and right sides of the upper guard 9. . The slide lock bar 19 is guided by the guide bracket 20 and allowed to slide in the left-right direction, and is restricted in rotation by forming a square cross section corresponding to the square hole 20a of the guide bracket 20.

Lock pins 19a are welded to the left and right sides of the slide lock bar 19, respectively, and these lock pins 19a protrude rearward (upward in FIG. 8) and bend at right angles toward the right (left in FIG. 8). Yes. Lock brackets 21 (locking means) are welded to the left and right sides of the upper front of the cab 5 so as to correspond to the left and right lock pins 19a when the upper guard 9 is in the protective position. The lock pin 19a is inserted into the lock hole 21a of the lock bracket 21 with the slide to the right.
The right end of the slide lock bar 19 protrudes rightward from the right guide bracket 21 and is welded with a disk-shaped spring seat 19b, and a spring 22 (biasing means) interposed between the spring seat 19b and the guide bracket 20 is welded. Thus, the slide lock bar 19 is always urged to the right. Due to the biasing force of the spring 22, the lock pin 19a of the slide lock bar 19 is held in a state of being inserted into the lock hole 21a of the lock bracket 21, and the slide lock bar 19 is moved to the left against the biasing force of the spring 22. The lock pin 19a can be removed from the lock hole 21a by sliding.

The left end of the slide lock bar 19 protrudes to the left from the left guide bracket 20, and the operation portion 19c is welded so as to form a T shape. Since the position of the operation unit 19c is close to the left door 5a of the cab 5, the operator can arbitrarily operate the operation unit 19c from the cab 5 through the door 5a. A handle 23 is welded to the left side surface of the upper guard 9 so as to be close to the operation portion 19c of the slide lock bar 19, and the upper guard 9 can be operated by gripping the handle 23.
A base end of a cylinder 24 (assist means) is connected to the right side of the front surface of the cab 5, and a rod 24 a of the cylinder 24 is connected to an intermediate portion of the interlocking arm 16. The high-pressure nitrogen gas sealed in the cylinder 24 acts in the direction in which the rod 24a protrudes, whereby the upper guard 9 is always urged to the protection position side via the interlocking arm 16. The urging force of the cylinder 24 is set so as to cancel the weight of the upper and lower guards 9 and 10.

Next, the operation of the guard structure of the cab glass of the excavator configured as described above will be described.
3 and 4, the upper and lower guards 9 and 10 are switched to the protection position, and the lock pin 19 a of the slide lock bar 19 is placed in the lock hole 21 a of the lock bracket 21. By being inserted, both guards 9 and 10 are held in the protective position. For this reason, rocks and the like flying from the front during work are blocked by the upper and lower guards 9 and 10, and the upper and lower glass 6, 7 and the operator are protected. When the upper and lower glass plates 6 and 7 become dirty during the work, wiping and cleaning are performed, and when the wiper blade of the wiper 8 is consumed, replacement work is performed. However, during the maintenance, the upper and lower glass plates 6 and 7 are cleaned. , 7 need to be exposed forward.

At this time, an operator such as an operator opens the door 5 a from the inside of the cab 5, grasps the operation portion 19 c of the slide lock bar 19, and slides it to the left against the urging force of the spring 22. As a result, the lock pin 19a is detached from the lock hole 21a of the lock bracket 21, and in this state, when the handle 23 is gripped and the upper guard 9 is operated to be inclined diagonally forward and downward, the interlock arm 16 rotates to rotate the cylinder 24. While retracting the rod 24a, the upper and lower guards 9, 10 are switched from the protective position to the open position. At this time, since the urging force of the cylinder 24 opposes the weight of the upper and lower guards 9 and 10, switching to the open position is performed gradually.
As shown in FIGS. 5 and 6, when the lower guard 10 is in a horizontal posture, the stopper member 13 comes into contact with the frame 5 b of the cab 5, and the tilting of the lower guard 10 is restricted and the movement of the upper guard 9 is also restricted. Switching to the open position is completed, and the upper and lower glasses 6 and 7 are exposed forward. Since the lower guard 10 in the open position is held in a horizontal posture, a space that can be used as a scaffold by the operator is formed on the lower guard 10. On the other hand, the upper guard 9 in the open position is separated from the cab 5. It is held in a substantially upright position at a position spaced a predetermined distance forward. Therefore, the operator can go around the door 5a of the cab 5 and get on the lower guard 10 to perform necessary maintenance such as glass wiping and wiper blade replacement.

Here, for example, in the hydraulic excavator of the present embodiment, the lower guard 10 when in the open position is located at a height of about 1.5 m from the ground. This work is very tense. At this time, the upper guard 9 that stands upright on the back of the operator not only plays an effective role in preventing the operator from falling, but also allows the operator to recognize that the operator has been prevented from falling, so that the worker can work at a high place. This works to relieve the operator's tension. Therefore, the operator can reduce the psychological burden and can perform maintenance efficiently and safely on the lower guard 10.
Further, the upper guard 9 in the open position can be used as a handrail for the operator. For example, in order to wipe the lower glass 7, it is necessary for the operator to bend over the lower guard 10. In such a case, the operator can easily change the posture while holding one side of the upper guard 9.

  In order to return the upper and lower guards 9 and 10 to the protection position after the maintenance work is completed, first of all, while grasping the handle 23 and operating the upper guard 9 diagonally upward, the slide lock bar 19 The user holds the operation unit 19c and slides leftward. Also at this time, since the urging force of the cylinder 24 opposes the weight of the upper and lower guards 9 and 10, it is possible to switch to the protective position with almost no operator's operation force required. When the operation portion 19c is released after the switching to the protection position is completed, the lock pin 19a of the slide lock bar 19 is inserted into the lock hole 21a of the lock bracket 21 by the urging force of the spring 22, and the upper and lower guards 9 are moved. , 10 are held in the protective position.

This is the end of the description of the embodiment, but the aspect of the present invention is not limited to this embodiment. For example, in the embodiment described above, a hydraulic excavator is used as a construction machine, but the present invention is not limited to this as long as the front glass of the cab 5 needs to be protected by a guard. May be.
In the above-described embodiment, the stopper member 13 provided on the lower end surface of the lower guard 10 is caused to abut on the frame 5b of the cab 5 to function as the holding means. However, the present invention is not limited to this. For example, a convex portion may be formed on the frame 5b side, and the tilt of the lower guard 10 may be regulated by the convex portion to be held in a horizontal posture.

In the above embodiment, the pair of lock pins 19a are provided on the slide lock bar 19, and the slide lock bar 19 is inserted into and removed from the left and right lock holes 21a simultaneously by the slide operation. is not. For example, instead of the slide lock bar 19, lock pins 19 a may be slidably provided on both the left and right sides, and these lock pins 19 a may be individually operated.
Moreover, in the said embodiment, although the front glass of the cab 5 was divided | segmented into the upper stage glass 6 and the lower stage glass 7, and the upper stage and the lower stage guards 9 and 10 were arrange | positioned corresponding to each, it is not restricted to this. . For example, the upper and lower guards 9 and 10 may be disposed so as to correspond to the upper and lower portions of one front glass.

5 Driver's cab 6 Upper glass 7 Lower glass 9 Upper guard 10 Lower guard 13 Stopper member (holding means)
16 Interlocking arm 19 Slide lock bar 19a Lock pin 19c Operation part 21 Lock bracket 21a Lock hole 22 Spring (biasing means)
23 Handle 24 Cylinder (assist means)

Claims (5)

In the guard structure of the operator's cab glass of the construction machine in which a guard that covers and protects the front glass is provided in front of the cab's front glass, and the guard that can be visually recognized in front is disposed.
A lower end is connected to the lower part of the cab so as to be tiltable and covers a lower part of the front glass, and an open position where the lower part of the front glass is exposed forward by being held in a substantially horizontal posture by a holding means. A lower guard that is switched by tilting about the lower end between,
The upper guard is connected to the upper end of the lower guard so that it can rotate relative to the upper cab, and the upper part is connected to the driver's cab side via an interlocking arm. An upper stage which is switched while rotating the interlocking arm around the operator's cab as the lower guard tilts between an open position where the upper part of the front glass is exposed forward and separated from the cabin. Guard,
A guard structure for a cab glass of a construction machine, comprising: locking means for fixing the upper guard and the lower guard to a protective position.   One end is connected to the driver's cab side, the other end is connected to the interlocking arm, and assist means for always biasing the upper guard to the protection position side through the interlocking arm is provided. The guard structure of the cab glass of the construction machine according to claim 1. The locking means is
A pair of lock brackets provided on the left and right sides of the front upper portion of the cab, each having a lock hole,
The upper guard is slid by an operating portion provided at one end of the upper guard and provided at one end. When the upper guard is in the protection position, the pair of lock pins are attached to both lock holes of the lock bracket along with the slide. A slide lock bar to be inserted into and removed from,
3. A guard structure for a cab glass for a construction machine according to claim 1, further comprising an urging means for urging the slide lock bar in a direction in which the lock pin is inserted into the lock hole. The upper guard and the lower guard are
A frame-like frame corresponding to the upper or lower portion of the front glass;
4. The guard structure for a cab glass of a construction machine according to claim 1, wherein the guard structure is composed of a lattice material arranged vertically and horizontally in the frame.   The guard structure for a cab glass of a construction machine according to any one of claims 1 to 4, wherein a handle is provided on one side of the upper guard.

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