JPH07257281A - Step device for construction machine - Google Patents

Abstract

PURPOSE:To prevent the damage of a step due to the collision of an obstacle by providing a motor fitted with a brake in the vicinity of a bracket for turning the motor by the operation of a switch, and by turning the step from the lower getting on and off position up to the upper housing position. CONSTITUTION:When a driver wants to get on the ground from a driver's room 10, the switch 13 provided inside the driver's room 10 is turned onto a contact point (a) from the neutral point N. Since an electric motor 17 fitted with a brake is turned in the normal direction, a step 19 is turned downwards at the side making a center of the axis of a boss 20 on the base side of the step. If the switch 13 is returned to its neutral position N when the step has reached the position A for getting on and off, the rotation of the motor 17 is stopped, and also the turning of the step 19 is stopped. Since the braking part 22 of the motor 17 operates negatively so as to apply the brake, the step 19 can be fixed in the getting on and off position A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step device for elevating a driver, which is mainly installed in construction machines such as hydraulic excavators and work vehicles.

[0002]

2. Description of the Related Art FIG. 11 is a perspective view showing an embodiment of a lifting step 1 described in Japanese Utility Model Laid-Open No. 4-130549. In this lifting / lowering step 1 of the prior art, a lifting / lowering step 1 having a substantially L-shaped cross section is rotatably attached to a lower position of a driver's cab door-2 by a hinge mechanism 3, and the step 1 is attached to the driver's cab door-2. When it is closed, it is rotated upwards to be stored, and when it is fully opened, it is tumbled in conjunction with the opening operation of the door-2 so as to project laterally. Note that FIG.
In the above, 4 is an upper revolving superstructure, 5 is an operator cab mounted on the upper revolving superstructure 4, and 6 is a connecting link.

[0003]

In the conventional hydraulic excavator shown in FIG. 11, steps are extended or stored in association with the opening / closing operation of the driver's cab door. During the work of the hydraulic excavator, the operation is performed by opening the door for the convenience of the driver's confirmation of work or the wish of the driver.
That is, since steps cannot be stored when the door is opened, running the hydraulic excavator in that state
Other obstacles wound up on the upper surface side of the crawler may collide with the step and damage the step. It is an object of the present invention to provide a step device that can solve the above problems.

[0004]

In the step apparatus of the present invention, an upper revolving structure is provided above a lower traveling structure, and an upper revolving structure is provided near the entrance / exit of a driver's cab mounted on the upper revolving structure. In the step device, a bracket is fixedly attached to the side surface of the upper revolving structure at a position below the entrance / exit, and a ladder frame-shaped step is attached to the bracket so as to be rotatable in the vertical direction of the side, and near the bracket. By providing a motor with a brake and rotating the motor with a switch by a switch operation, the step can be rotated from a lower lift position to an upper storage position. Further, in the above step device, a ladder frame-shaped step is formed by being divided into an upper step and a lower step, and a lower end portion of the upper step and an upper end portion of the lower step are pin-coupled so as to be bent and rotatable. By rotating the upper side step to the upper storage position, the lower side step is made into a folded state in which the upper side step is folded in two. Alternatively, a bracket is fixed to the side surface of the upper swing body at a position below the entrance of the operator's cab, and a substantially L-shaped step is provided on the bracket in a vertical direction to the side when viewed from the front-rear direction of the upper swing body. The step cylinder is rotatably mounted, and a step cylinder is provided inside the front part of the upper revolving structure, and the rod tip end of the step cylinder is connected to one end part on the base side of the step to extend and retract the step cylinder. Thus, the step can be rotated to a side elevation position and a storage position on the lower surface side of the upper swing body.

[0005]

A bracket is fixed to the side surface of the upper revolving structure at a position below the entrance / exit of the driver's cab, and a ladder frame-shaped step is attached to the bracket so as to be rotatable in the lateral vertical direction. An electric motor with a brake is provided in the vicinity, and by rotating the electric motor with a brake by a switch operation, the step device that rotates the step over the storage position above the lower elevating position is By operating the switch as required by the driver, the step is rotated over the range of the storage position above the lower elevating position and stopped and fixed regardless of the open or closed state of the cab door. can do. Further, in the above step device, a ladder frame-shaped step is formed by being divided into an upper step and a lower step, and a lower end portion of the upper step and an upper end portion of the lower step are pin-coupled so as to be bent and rotatable. In the step device, when the step is rotated to the lower elevating position, the lower end of the lower step can be lowered to a position close to the ground. Further, when the step is rotated to the upper storage position, the upper step and the lower step can be folded and stored in a folded state.

Further, a bracket is fixedly provided on a side surface of the upper revolving superstructure at a position below the entrance / exit of the operator's cab, and a substantially L-shaped step as viewed from the front-rear direction of the upper revolving superstructure is laterally provided on the bracket. In the step device in which the step cylinder is mounted rotatably in the direction, the step cylinder is provided inside the front part of the upper revolving structure, and the rod tip end of the step cylinder is connected to the one end part on the base side of the step, By operating the switch as required, the step can be rotated to the raising / lowering position on the side of the upper revolving structure and the storage position on the lower side of the upper revolving structure regardless of whether the door in the cab is open or closed. be able to.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a side view of essential parts of a hydraulic excavator equipped with a step device 7 according to a first embodiment of the present invention. In the figure, 8 is a lower traveling body of the hydraulic excavator, 9 is an upper revolving superstructure, 10 is a driver's cab mounted on the upper revolving superstructure 9, 11 is a door of the operator's cab 10 (in FIG. 1, the door 11 in an open state is shown. , 12 is an entrance / exit of the driver's cab 10, 13 is a switch for the step device 7 provided inside the driver's cab 10, 14
Is a crawler belt wound around the undercarriage 8. Figure 2
FIG. 2 is a detailed view of part A of FIG. 1. In the figure, reference numerals 15 and 16 denote front and rear brackets fixed to the side surface of the upper swing body 9, respectively, 17 denotes an electric motor with a brake fixedly attached to the bracket 15, and 18 denotes a drive shaft of the electric motor with brake 17. Reference numeral 19 is a step in the shape of a ladder frame, 20 is a base side boss of step 19, and 21 is a drive shaft connecting hole formed in the shaft center of the base side boss 20. FIG. 3 shows B of FIG.
FIG. In the figure, reference numeral a indicates the ascending / descending position of step 19, and reference numeral b indicates the storing position. FIG. 4 is an electric circuit diagram of the step device 7. In the figure, 22 is a brake section of the electric motor 17 with a brake, and 2
3 is a power supply. FIG. 5 is a side view of essential parts showing a state in which step 19 is stored in the storage position b.

Next, the structure of the step device 7 of the first embodiment of the present invention will be described with reference to FIGS. In the step device 7 of the present invention, brackets 15 and 16 are fixedly provided on the side surface of the upper revolving superstructure 9 at a position below the entrance / exit 12 of the cab 10, and the bracket frame-shaped step 19 is attached to the brackets 15 and 16. The bracket 15 is mounted so as to be rotatable in the vertical direction, and the bracket 15 is provided with an electric motor 1 with a brake.
7 is fixed and installed, and the electric motor with brake 1
The drive shaft 18 of No. 7 was fitted in the drive shaft connecting hole portion 21 of the boss 20 on the base side at step 19.

Next, the operation of the step device 7 of the first embodiment will be described. Here, it is assumed that step 19 is at the storage position b (shown in FIG. 5) at the beginning of the description. When the driver wants to get off from the cab 10 to the ground (GL), the switch 13 provided inside the cab 10 is operated from the neutral contact N (shown in FIG. 4) to the contact a. Since the electric motor 17 with a brake rotates in the normal direction, the step 19 rotates laterally downward about the axis of the base side boss 20. When the step 19 reaches the elevating position B (shown in FIGS. 2 and 5), the switch 13
Is returned to the neutral position N, the rotation of the electric motor with brake 17 is stopped, and the rotation of step 19 is also stopped. Since the brake portion 22 of the electric motor with brake 17 negatively brakes, step 19 can be fixed at the elevating position a. Step 19 in the raising / lowering position a
Is stored in the storage position b, the switch 13 is operated from the neutral contact N to the contact b (shown in FIG. 4). Since the electric motor with brake 17 rotates in the reverse direction, the step 19 can be rotated laterally upward. That is, in the step device 7, the driver switches the switch 13 as required.
By performing the operation, regardless of whether the door 11 of the cab 10 is open or closed, the step 19 can be rotated over the range of the storage position b above the lower elevating position a and stopped and fixed. it can. Although the brake electric motor 17 is used as the brake motor in this embodiment, a motor that is not an electric motor and operates by hydraulic pressure or pneumatic pressure (not shown) may be used.

Next, FIG. 6 is a front view of essential parts showing a step device 24 according to a second embodiment of the present invention. In the figure, the first
The same components as those of the step device 7 of the embodiment are designated by the same reference numerals. 25 is a step device 24
Step, 26 is the upper step of step 25, 2
Reference numeral 7 is a lower step, and 28 is a pin that rotatably connects the lower end of the upper step 26 and the upper end of the lower step 27. Next, the step device 2 of the second embodiment
4 will be described with reference to FIG. In this step device 24, the step in the step device 7 of the first embodiment is divided into an upper step 26 and a lower step 27 in a ladder frame shape as step 25,
The lower end of the upper step 26 and the lower step 27
The upper end of each of them was connected by a pin 28. As a result, when the step 25 is rotated to the lower elevating position a ′, the lower end of the lower step 27 can be lowered to a position close to the ground (GL). When the step 25 is rotated to the upper storage position b ', the upper side step 26 and the lower side step 27 can be folded and stored in a folded state.

Next, FIG. 7 is a front view of essential parts showing a step device 29 according to a third embodiment of the present invention. In the figure, 30
Is an upper revolving structure, 31 is a bracket fixed to the side surface of the upper revolving structure 30 below the entrance (not shown) of the operator's cab 32, 33 is a step, 34 is a step hydraulic cylinder, and 35 is an upper part. A bracket for supporting the hydraulic cylinder 34 provided inside the revolving structure 30, and 36 is a step 3
3 is a pin pivotally supporting the base side boss 37 on the bracket 31; 38 is a bracket fixed to the base side boss 37;
Is attached to the bracket 38 by the rod tip portion 4 of the hydraulic cylinder 34.
It is a pin that rotatably connects 0. 8 is shown in FIG.
Step 33 of the step device 29 of the third embodiment in
FIG. FIG. 9 is an operation circuit diagram of step 29. In the figure, 41 is an electromagnetic switching valve for controlling the hydraulic cylinder 34, 42 is a hydraulic pump, 43 is an oil tank,
13 'is a switch and 23' is a power supply. FIG. 10 is a partially cutaway front view showing a stored state of the step device 29 in FIG. 7.

Next, the construction of the step device 29 of the third embodiment of the present invention will be described with reference to FIGS. In the step device 29 of the present invention, the bracket 31 is fixedly installed on the side surface of the upper swing body 30 at a position below the entrance / exit of the cab 32, and the bracket 31 has a substantially L shape when viewed from the front-rear direction of the upper swing body 30. A step 33 having a character shape is rotatably attached in a vertical direction to the side, and a step hydraulic cylinder 34 is provided inside the front side of the upper swing body 30.
The rod tip 40 of No. 4 is connected to the bracket 38 fixed to the base side boss 37 of the step 33, and the step 33 is moved up and down by the expansion and contraction operation of the hydraulic cylinder 34, and the lower revolving structure 30 is stored on the lower surface side. It is constructed so that it can be rotated to the use position D.

Next, the operation of the step device 29 of the third embodiment will be described. Here, it is assumed that step 33 is at the storage position D of the upper swing body 30 at the beginning of the description. When the driver wants to get off the ground from the cab 32, the switch 1 provided inside the cab 32
3'is operated from the neutral contact N '(shown in FIG. 9) to the contact C. Since the left solenoid 44 of the electromagnetic switching valve 41 is energized, the electromagnetic switching valve 41 switches from the neutral position to the E position.
The discharge pressure oil from the hydraulic pump 42 is supplied to the bottom side oil chamber 45 of the hydraulic cylinder 34 through the E position of the electromagnetic switching valve 41, and the return oil from the rod side oil chamber 46 is supplied to the oil tank 43 through the E position. Will be returned. As a result, the hydraulic cylinder 34 is extended, so that the step 33 can be extended to the lateral elevating position C as shown in FIG. Further, when the step 33 in the lifting position C is stored in the storage position D, the switch 13 'is set to the neutral position N'.
The contact point d is operated. Since the right solenoid 47 of the electromagnetic switching valve 41 is energized, the electromagnetic switching valve 41 switches from the neutral position to the position. Therefore, since the hydraulic cylinder 34 is contracted, step 33 can be stored in the storage position D on the lower surface side of the upper swing body 30 as shown in FIG. That is, in this step device 29, the driver operates the switch 13 'as required, so that the step 33 is moved to the side regardless of whether the door (not shown) of the cab 32 is open or closed. It can be extended or stored on the lower surface side of the upper swing body 30. In this embodiment, the hydraulic cylinder 34 is used as the step cylinder, but a pneumatic cylinder that operates by pneumatic pressure instead of hydraulic pressure may be used.

[0014]

According to one embodiment of the prior art, the step device includes:
There is one in which a step is extended or stored in association with the opening / closing operation of the driver's door. Therefore, when performing work by opening the door, steps cannot be stored. Therefore, when the construction machine travels when the door is opened, another obstacle wound on the upper surface of the crawler track may collide with the above step. However, in the step apparatus of the present invention, a bracket is fixedly mounted on the side surface of the upper revolving structure at a position below the entrance / exit of the operator's cab, and the step is attached to the bracket so as to be rotatable in the lateral vertical direction, and the upper revolving structure is rotated. By means of a motor with a brake or a stepping cylinder arranged in the front part of the body, the step is extended to the lower or side elevation position or stored in the upper or upper revolving body lower side storage position. In the present invention, the driver can operate the brake motor or the step cylinder by operating the switch as required,
It is possible to rotate the step over the range between the raising and lowering position and the storing position and stop and fix the step regardless of whether the door of the cab is open or closed. In a step device in which a ladder frame-shaped step is formed by being divided into an upper step and a lower step, and the lower end portion of the upper step and the upper end portion of the lower step are pin-coupled so that they can be bent and rotated. When rotated to the lower lifting position,
The lower end of the lower step can be lowered to a position close to the ground. Further, when the step is rotated to the upper storage position, the upper step and the lower step can be folded and stored in a folded state.

[Brief description of drawings]

FIG. 1 is a side view of a main part of a hydraulic excavator equipped with a step device according to a first embodiment of the present invention.

FIG. 2 is a detailed view of part A of FIG.

FIG. 3 is a front view of a main part as seen from B of FIG.

FIG. 4 is an electric circuit diagram of the step apparatus according to the first embodiment of the present invention.

5 is a side view of an essential part showing a state in which the steps in FIG. 2 are stored in the storage position.

FIG. 6 is a front view of essential parts showing a step device according to a second embodiment of the present invention.

FIG. 7 is a front view of essential parts showing a step device according to a third embodiment of the present invention.

FIG. 8 is a perspective view showing steps in FIG. 7.

FIG. 9 is an operation circuit diagram of a step device according to a third embodiment of the present invention.

FIG. 10 is a partially cutaway front view showing a housed state of the step device in FIG.

FIG. 11 is a perspective view showing an elevating step according to an embodiment of the prior art.

[Explanation of symbols]

 4,9,30 Upper revolving structure 5,10,32 Driver's cab 7,24,29 Step device 11 Door 12 Entrance / exit 13,13 'switch 15,16,31,35,38 Bracket 17 Electric motor with brake 19,25 , 33 step 20 base side boss 26, 27 upper side, lower side step 28, 36, 39 pin 34 hydraulic cylinder 40 rod tip 41 electromagnetic switching valve

Claims (3)

[Claims] 1. An upper revolving structure is provided above the lower traveling structure,
In a step device for raising and lowering provided in the vicinity of an entrance / exit of a driver's cab mounted on the upper swing structure, a bracket is fixedly attached to a side surface portion of the upper swing structure at a position below the entrance / exit, and a ladder frame is attached to the bracket. -Like steps are mounted so as to be rotatable vertically in the lateral direction, and a motor with a brake is provided near the bracket, and the motor with a brake is rotated by a switch operation to move the step above the lower lifting position. A step device for a construction machine, wherein the step device is adapted to be rotated over a storage position of the. 2. The step device for a construction machine according to claim 1, wherein a ladder frame-shaped step is divided into an upper step and a lower step, and the lower step and the lower step of the upper step are formed. The upper step of the side step is bent and pivotally connected by a pin, and the upper step is rotated to the upper storage position so that the lower step is folded in two with respect to the upper step. A step device for a construction machine, which is characterized in that 3. An upper revolving structure is provided above the lower traveling structure,
In the step device for raising and lowering, which is provided near the entrance / exit of the operator's cab mounted on the upper swing structure, a bracket is fixedly attached to the side surface of the upper swing structure at a position below the entrance / exit, and the bracket is attached to the upper part. When viewed from the front-rear direction of the revolving structure, a substantially L-shaped step is mounted rotatably in the vertical direction of the side, and a step cylinder is provided inside the front part of the upper revolving structure, and the rod tip of the step cylinder is provided. Is connected to one end of the above step on the base side, and the step cylinder can be expanded and contracted to rotate the step to a side elevation position and a storage position on the lower surface of the upper swing body. Step equipment for construction machinery.