JP2004060664A - Working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working machine for avoiding involving itself in unexpected events and improving its safety by allowing the operation of a driven body such as working equipment or a moving cab even in such emergency that the supply of pressure oil from a hydraulic pressure generating source is interrupted. <P>SOLUTION: In the working machine, an accumulator 45 is connected to a link operating circuit 34 at its meter-in side via a communicating circuit 36 in which a communication valve 48 is inserted having an electromagnetic operation part 48a to be energized by the operation of an emergency operation switch 50 set up in the cab 7 using a battery 49 as a power supply and similarly the accumulator 45 is connected to a working equipment operating circuit 33 at its meter-in side via the communicating circuit 36. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a working machine including a hydraulic actuator and a driven body driven by the hydraulic actuator, and more particularly, to a work machine capable of responding to an emergency by driving the driven body even in an emergency such as when a hydraulic supply source is cut off. It concerns machines.
[0002]
[Prior art]
Generally, a working machine is configured such that pressure oil from a hydraulic pump driven by an engine is supplied to a hydraulic actuator that drives a working machine or the like via a control valve, and the operating valve or the like is operated by operating the control valve. A desired operation can be performed. Therefore, when the engine is stopped due to a failure or a shortage of fuel, pressure oil is not supplied to the hydraulic actuator even if the control valve is operated, so that the operation of the working machine or the like is naturally stopped. In such an emergency, there is a case where it is desired to operate the work machine or the like even temporarily for the reason of moving the work object, adjusting and repairing the machine, preparing for the work, and avoiding an unexpected situation.
[0003]
In particular, in a working machine having a movable cab, there is a high need to move the cab to a position where the operator can easily exit, in order to further enhance safety.
[0004]
On the other hand, conventionally, in the case of a mechanism that only moves the cab up and down via a parallel link by expansion and contraction of a hydraulic cylinder, for example, in an emergency, the bottom oil chamber and the head oil chamber of the hydraulic cylinder are short-circuited (Japanese Patent Laid-Open 2002-104795), the cab is lowered to a position where the operator can easily exit by utilizing the gravitational action of the cab, the parallel link, and the weight of the operator.
[0005]
[Problems to be solved by the invention]
However, for example, in a configuration in which not only the raising / lowering operation of the cab but also the cab can be extended forward by a double parallel link mechanism in which two parallel links are connected in series, the hydraulic pressure for driving the parallel link related to the extension operation is provided. Since the cab cannot be pulled back unless pressure oil is supplied to the cylinder, there is a problem that a special evacuation route must be provided for an operator to leave the cab in an emergency.
[0006]
The present invention has been made in order to solve such a problem, and even in an emergency where the supply of pressure oil from a hydraulic pressure source is interrupted, a driven body such as a working machine or a movable cab is used. It is an object of the present invention to provide a working machine capable of operating a computer, thereby avoiding an unexpected situation and improving safety.
[0007]
[Means for Solving the Problems and Functions / Effects]
In order to achieve the above object, a work machine according to a first aspect of the present invention
In a work machine including a hydraulic actuator for driving a driven body, an accumulator as a power source for supplying pressure oil to the hydraulic actuator is provided.
[0008]
According to the present invention, since the accumulator is provided as a power source for supplying the pressure oil to the hydraulic actuator that drives the driven body, the supply of the pressure oil from the hydraulic pressure source to the hydraulic actuator is interrupted. Even in an emergency, the driven body can be driven by the pressure oil supplied from the accumulator. Therefore, for example, when the driven body is a working machine including a boom, an arm, and the like, and the hydraulic pressure generation source is a hydraulic pump driven by the engine, even when the engine is stopped due to a failure or a shortage of fuel, The working machine can be moved in response to the movement of the work object, machine adjustment, repair, work preparation, and the like, and unexpected situations can be avoided.
[0009]
In the first invention, a first parallel link related to the extension / retraction operation of the driven body and a second parallel link related to the elevating operation of the driven body are connected in series, and a tip of the second parallel link is Preferably, the driven body is connected, and the hydraulic actuator includes a first link cylinder for driving the first parallel link and a second link cylinder for driving the second parallel link (second invention). ). In this way, even in an emergency, the driven body can be moved in a wide range up and down, back and forth, and a combination thereof to return to a desired position. Here, for example, when the desired return position of the driven body is at a lower position in front of the overhang direction, the driven body can be connected to the first link cylinder only by supplying pressure oil from the accumulator to the first link cylinder. It can be returned to the return position. The reason is that the driven body can be lowered by the gravity effect of the weight of the driven body and the like. In the configuration in which the pressure oil from the accumulator can be supplied to both the first link cylinder and the second link cylinder, even if the desired return position of the driven body is the upper position just before the extending direction, the driven It goes without saying that the body can be returned to its return position.
[0010]
In the first invention or the second invention, the driven body is preferably a cab (third invention). In this way, even in an emergency, the cab can be returned to the home position (the cab position when the operator normally gets on and off), so that the operator can safely exit from the cab, and safety can be improved. Improvement can be achieved.
[0011]
In the first invention to the third invention, a communication valve for opening and closing the oil passage is interposed in an oil passage connecting the hydraulic actuator and the accumulator, and an operation switch for operating switching of the communication valve is provided. (4th invention). In this case, the above-described effect can be obtained with a relatively simple configuration. In the case where the driven body is a cab, if an operation switch is installed in the cab, an emergency response can be made at the discretion of the operator, and if the operation switch is installed on the working machine body other than the cab, Even if the operator is unable to travel on his own due to illness or the like in an emergency, it is possible for other workers to operate the cab to return to the home position from the work machine main body side, making it impossible to travel inside the cab Can be safely rescued.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, specific embodiments of the working machine according to the present invention will be described with reference to the drawings.
[0013]
FIG. 1 is a side view showing a working state of a working machine according to one embodiment of the present invention. FIG. 2 is a view showing a movable cab and a double parallel link mechanism. FIG. 2A is a view showing a state where the cab is located at a home position, and FIG. 2B is a view showing a state where the cab is projected upward and forward. ) Are shown.
[0014]
The work machine 1 of the present embodiment can be moved by self-propelled itself used for, for example, harbor unloading work and the like, and has a tracked lower traveling body 2 and a frame of a vehicle body 2 a in the lower traveling body 2. It is provided with a column 3 having a required height standing upright in the center of the upper surface, and an upper revolving unit 5 attached via a revolving mechanism 4 provided on the upper part of the column 3.
[0015]
The upper swing body 5 is provided with a long working machine (driven body) 6 and a movable cab (driven body) 7 at the front thereof, and a driving engine and a hydraulic unit at the rear thereof. , A counterweight, and other devices are provided.
[0016]
On both sides of the upper revolving structure 5, landings 8 provided with handrails 8a are provided so that an operator can get on and off the cab 7 and check and maintain the engine, equipment and the like safely. Also, the column 3 is provided with ramps 9, 9 'for ascending and descending from the vehicle body 2a to the upper revolving structure 5, and a landing 10 serving as a relay and a scaffold for maintenance is provided at an intermediate position. Have been. In addition, the ramp 9 for moving from the relay landing 10 to the upper swing body 5 is fixed to the upper swing body 5 side so as not to hinder the swing operation of the upper swing body 5.
[0017]
The working machine 6 has a boom 13 whose base end is pivotally attached to a working machine support frame (not shown) fixedly mounted on the upper swing body 5, and a base end portion which is pivotally attached to a distal end of the boom 13. An arm 14 and a clamshell bucket 15 suspended at the tip of the arm 14 are operated. The boom 13 and the arm 14 are rotated by the operation of boom cylinders 16 and 16 and the arm cylinder 17, respectively. The crane shell bucket 15 can be moved over a wide range by the bending and undulating operation of the working machine 6 to perform the cargo handling work. The clamshell bucket 15 is a hydraulically operated bucket. In the present embodiment, in addition to the two boom cylinders 16, 16, an assist cylinder 18 for assisting the boom raising operation is provided at an intermediate position between the two boom cylinders 16, 16.
[0018]
The cab 7 constitutes a cab, and is attached to the upper swing body 5 via a double parallel link mechanism 20, as shown in FIG. Here, the double parallel link mechanism 20 includes a first parallel link 21 pivotally attached to a bracket 19 fixed on the upper swing body 5 and a second parallel link 21 pivotally attached to a cab support frame 24 that supports the cab 7. The two parallel links 23 are connected in series by the relay bracket 22. In the present embodiment, the double parallel link mechanism 20 includes a first link cylinder 25 as a hydraulic cylinder for driving the first parallel link 21 and a second link cylinder 26 as a hydraulic cylinder for driving the second parallel link 23. Each is provided. The extension and contraction of the first link cylinder 25 causes the first parallel link 21 to stand up and lie down, respectively, and the upright operation and the prone operation of the first parallel link 21 cause the cab 7 to retract and extend respectively. Is being done. The extension and contraction of the second link cylinder 26 causes the second parallel link 23 to rotate upward and downward, respectively, and the upward and downward rotation of the second parallel link 23 causes the cab to rotate, respectively. 7, the ascending operation and the descending operation are performed. In this manner, the cab position is indicated by a solid line in FIG. 2 (a) in a wide range, up and down, front and back, and a combination thereof by raising / lowering, extending / retracting operations of the cab 7 as shown in FIGS. 2 (a) and 2 (b). From the home position to be moved. Here, the home position is a state position of the cab 7 when the first parallel link 21 is raised most and the second parallel link 23 is lowered most, and the operator can safely perform a normal getting on / off operation. This is the cab position that can be performed.
[0019]
In the present embodiment, the cab 7 has a conventionally well-known structure, and is provided on the upper surface of the cab support frame 24 with a cushioning mechanism (for example, a rubber mount, a viscous mount, or the like) similar to the cab of the conventional working machine. (Not shown). Although not shown in detail, operating devices installed inside the cab 7 are connected to respective operating devices on the upper swing body 5 via flexible piping, cables, harnesses, and the like. A landing 12 provided with a handrail 12a is provided on the cab support frame 24 on the entrance and exit side of the cab 7 (see FIG. 1).
[0020]
Here, the first parallel link 21 includes link members 27 (27 ') each formed of a link having a required length provided on the left and right at a predetermined distance and arranged in front and rear parallel. On the other hand, the second parallel link 23 has a link member 28 (28 ') similar to the link member 27 (27') arranged vertically in parallel. In the present embodiment, the left and right links of the link member 27 'at the subsequent stage of the first parallel link 21 and the link member 28' at the upper stage of the second parallel link 23 are mutually connected by a plurality of cross beams (not shown). The cross beams are connected so that when the operator needs to escape to the outside, the cross beams become steps.
[0021]
Next, a hydraulic circuit for driving the work implement 6 and the double parallel link mechanism 20 will be described with reference to a drive hydraulic circuit diagram of FIG.
[0022]
The drive hydraulic circuit 30 according to the present embodiment includes a variable displacement hydraulic pump 32 driven by an engine 31, a work machine operation circuit 33 for operating the work machine 6, and a link operation for operating the double parallel link mechanism 20. A circuit 34 and an energy recovery circuit 35 for recovering the potential energy of the work machine 6 are provided.
[0023]
The work machine operating circuit 33 has a boom switching valve 41 for switching the expansion and contraction operation of the boom cylinders 16, 16. When the boom switching valve 41 is switched to the position a in FIG. Pressurized oil is supplied to the bottom oil chambers of the boom cylinders 16, 16 via the boom switching valve 41, and return oil from the head-side oil chambers of the boom cylinders 16, 16 causes the boom switching valve 41 to operate. The boom cylinders 16 and 16 are configured to be returned to the tank 42 by way of an extension. Further, when the boom switching valve 41 is switched to the position b in the drawing, the pressure oil from the hydraulic pump 32 is supplied to the head-side oil chambers of the boom cylinders 16, 16 via the boom switching valve 41. At the same time, the return oil from the bottom-side oil chambers of the boom cylinders 16, 16 is returned to the tank 42 via the boom switching valve 41, whereby the boom cylinders 16, 16 are configured to contract. Thus, the switching operation of the boom switching valve 41 causes the boom cylinders 16, 16 to expand and contract, whereby the boom 13 is raised and lowered. Although not described in detail in the drawings, the working machine operating circuit 33 includes an operating circuit similar to the operating circuit for the boom cylinders 16 and 16 for opening and closing the arm cylinder 14 and the clamshell bucket 15. It is formed corresponding to each hydraulic cylinder.
[0024]
The link operation circuit 34 has a first link switching valve 43 for switching the expansion and contraction operation of the first link cylinder 25. When the first link switching valve 43 is switched to the position a in FIG. 32 is supplied to the bottom oil chamber of the first link cylinder 25 via the first link switching valve 43, and the return oil from the head oil chamber of the first link cylinder 25 is The flow is returned to the tank 42 via the one-link switching valve 43, whereby the first link cylinder 25 is extended. When the first link switching valve 43 is switched to the position “b” in the drawing, the pressure oil from the hydraulic pump 32 is supplied to the head-side oil chamber of the first link cylinder 25 via the first link switching valve 43. And the return oil from the bottom side oil chamber of the first link cylinder 25 is returned to the tank 42 through the first link switching valve 43 so that the first link cylinder 25 contracts. It is configured. In this way, the switching operation of the first link switching valve 43 causes the first link cylinder 25 to expand and contract, thereby performing the retracting operation and the extending operation of the cab 7. Although the detailed illustration is omitted, the operating speed of the first link cylinder 25 is adjusted by a meter-out method, and particularly, the sudden extension operation of the cab 7 is prevented. .
[0025]
Further, the link operation circuit 34 has a second link switching valve 44 for switching the expansion / contraction operation of the second link cylinder 26. When the second link switching valve 44 is switched to the position a in FIG. The pressure oil from the hydraulic pump 32 is supplied to the bottom oil chamber of the second link cylinder 26 via the second link switching valve 44, and the return oil from the head oil chamber of the second link cylinder 26 is discharged. The flow is returned to the tank 42 via the second link switching valve 44, whereby the second link cylinder 26 is configured to extend. When the second link switching valve 44 is switched to the position b in the drawing, the pressure oil from the hydraulic pump 32 is supplied to the head-side oil chamber of the second link cylinder 26 via the second link switching valve 44. And the return oil from the bottom side oil chamber of the second link cylinder 26 is returned to the tank 42 via the second link switching valve 44, so that the second link cylinder 26 contracts. It is configured. In this manner, the switching operation of the second link switching valve 44 causes the second link cylinder 26 to expand and contract, whereby the raising and lowering operations of the cab 7 are performed. Although the detailed illustration is omitted, the operating speed of the second link cylinder 26 is adjusted by a meter-out method like the first link cylinder 25, and particularly, the cab 7 Operation is to be prevented.
[0026]
The switching valve for the working machine 6 including the switching valve 41 for the boom, the switching valve 43 for the first link, and the switching valve 44 for the second link are all directional switching valves of a pilot pressure operation type. Although a detailed illustration is omitted, a predetermined pilot pressure from a pilot pressure control valve acts on a switching valve corresponding to the lever operation by operating a working machine operation lever or a cab operation lever provided in the cab 7. Thus, the switching valve is switched.
[0027]
The energy recovery circuit 35 has a closed circuit formed between a bottom oil chamber of the assist cylinder 18 and an accumulator 45 connected to the bottom oil chamber. The accumulator 45 used in the present embodiment is a piston-type accumulator, and is mounted on the upper swing body 5 near the bracket 19 (see FIGS. 2A and 2B). In this way, the potential energy when the boom 13 is lowered is converted into hydraulic energy and stored, and when the boom 13 is raised, the stored energy is released and used as energy for raising the boom 13. Further, a relief valve 46 is attached to the energy recovery circuit 35, and the pressure in the circuit is set to a set pressure (350 kg / cm). ² When the above is reached, the pressure oil in the circuit is drained to the tank 42. Note that what is indicated by reference numeral 47 is a check valve.
[0028]
In the present embodiment, the accumulator 45 in the energy recovery circuit 35 and the meter-in side in the link operation circuit 34 are connected by a communication circuit 36 in which a communication valve 48 is inserted. Here, the communication valve 48 is an electromagnetically operated switching valve, and has an electromagnetic operation section 48a that is energized by operating an emergency operation switch 50 installed in the cab 7 using the battery 49 as a power supply. When the emergency operation switch 50 is turned on and the electromagnetic operation section 48a is energized, the communication valve 48 is switched to the position a in the figure, and the meter-in side of the link operation circuit 34 communicates with the accumulator 45. On the other hand, when the emergency operation switch 50 is turned off and the electromagnetic operation section 48a is turned off, the communication valve 48 is set to the position b in the figure, and the meter-in side of the link operation circuit 34 and the accumulator 45 are not connected. It becomes.
[0029]
Similarly, the accumulator 45 and the meter-in side of the working machine operating circuit 33 are connected by the communication circuit 36, and the working machine is operated by switching the communication valve 48 by turning on or off the emergency operation switch 50. The meter-in side of the operation circuit 33 and the accumulator 45 are in communication or non-communication.
[0030]
In the working machine 1 of the present embodiment configured as above, the operator gets on the cab 7 via the vehicle body 2a, the ramps 9, 9 'and the landings 8, 12. For example, in the case of unloading bulk cargo of the cargo ship S as a port cargo handling operation, the lower traveling body 2 is driven to move the work machine 1 to the quay B while the work machine 6 is kept in a low attitude. At the same time, as shown in FIG. 1, the working machine 6 is arranged so as to be able to be inserted into the hold S ′. Then, by operating the working machine operation lever in the cab 7, the boom 13 and the arm 14 are operated to perform the bending and undulating operation of the working machine 6, and the clamshell bucket 15 is operated to load the cargo in the hold S '. And carrying out the loading and unloading of a load to a hopper (not shown) located at a side position of the work machine 1 by the turning motion of the upper turning body 5. In such a landing operation, at first, energy for lifting the weight of the working machine 6 + the amount of the piled-up load is required, but thereafter, the potential energy of the working machine 6 is converted into hydraulic energy, and the energy is stored in the accumulator 45. Since the stored hydraulic energy is used, the landing operation can be performed with a small amount of energy by utilizing the stored hydraulic energy. Further, the operator performs operations of raising, lowering, extending, and retracting the cab 7 as shown in FIGS. 2A and 2B in order to look over the interior of the hold S ′, and by performing these operations, up, down, forward and backward in a wide range. And the cab position is appropriately moved from the home position indicated by the solid line in FIG.
[0031]
When the engine 31 stops due to a failure or a shortage of fuel during such landing operations, each of the switching valves (the boom switching valve 41, the first link switching valve 43, and the second link switching valve 44). ) Is not supplied with hydraulic oil from the hydraulic pump 32 to the hydraulic actuators (the boom cylinders 16, 16, the first link cylinder 25, the second link cylinder 26, etc.). The operation of the cab 7 stops. In such an emergency, since the first link cylinder 25 cannot be extended, the protruding cab 7 cannot be pulled back. In such a case, if the operator turns on the emergency operation switch 50 and then operates the cab operation lever to pull back the cab 7, the cab 7 can be pulled back. That is, when the operator turns on the emergency operation switch 50, the communication valve 48 is switched to the position a in FIG. 3, and the meter-in side of the link operation circuit 34 and the accumulator 45 are connected. As a result, the pressure oil stored in the accumulator 45 can be supplied to the first link cylinder 25 (and the second link cylinder 26). If the operator operates the cab operating lever to switch the first link switching valve 43 to the position a in FIG. 3, the pressure oil stored in the accumulator 45 is transferred to the bottom side oil chamber of the first link cylinder 25. The first link cylinder 25 is extended by this, and the cab 7 is pulled back.
[0032]
On the other hand, the cab 7 which has risen to the high position can operate the cab operating lever so as to switch the second link switching valve 44 to the b position, and the cab 7 and the second parallel link 23, the weight of the operator, etc. The cab 7 can be lowered by the action of gravity. Incidentally, if the cab operation lever is operated so as to switch the second link switching valve 44 to the position b after the emergency operation switch 50 is turned on, even if the counter balance circuit is incorporated, the same as in the prior art described above. The cab 7 can be lowered without providing a short-circuit valve.
[0033]
In the emergency, there are times when it is desired to operate the work machine 6 for moving the cargo ship S, adjusting and repairing the machine, preparing for work, and the like. In such a case, after the operator turns on the emergency operation switch 50, the work implement 6 can be operated by operating the work implement operation lever. That is, when the operator turns on the emergency operation switch 50, the communication valve 48 is switched to the position a in FIG. 3, and the meter-in side of the working machine operation circuit 33 and the accumulator 45 are connected. As a result, the pressure oil stored in the accumulator 45 can be supplied to, for example, the boom cylinders 16, 16. Then, if the operator operates the cab operation lever to switch the boom switching valve 41 to the position a in FIG. 3, the pressure oil stored in the accumulator 45 is supplied to the bottom side oil chambers of the boom cylinders 16, 16. As a result, the boom cylinders 16 and 16 are extended, and the boom 13 is raised.
[0034]
According to the present embodiment, the work machine 6 can be operated and the cab 7 can be returned to the home position even in the above-described emergency, so that an unexpected situation can be avoided. , The operator can safely exit the cab 7.
[0035]
In the present embodiment, the accumulator 45 provided mainly for recovering the potential energy of the working machine 6 is used as a pressure oil supply source in an emergency. However, the present invention is not limited to this. A dedicated accumulator may be provided as a supply source, and the dedicated accumulator may be connected to the meter-out side of the working machine operating circuit 33 and the link operating circuit 34 via the communication circuit 36. In such a configuration, the pressure oil normally sent from the hydraulic pump 32 is supplied as the pressure oil stored in the dedicated accumulator.
[0036]
The emergency operation switch 50 may be further provided at an appropriate position other than the cab 7, for example, on the upper swing body 5 or the landing 8, and each switching valve may be operated on the upper swing body 5 or the like. In this way, even in the case of the emergency, and even if the operator is unable to travel on his own in the cab 7 due to illness or the like, another worker moves the cab 7 from the upper revolving structure 5 or the like to the home position. It is possible to perform an operation for returning the vehicle, and it is possible to safely rescue an operator who cannot travel in the cab 7.
[0037]
In the present embodiment, an example in which the present invention is applied to a hydraulic shovel type harbor cargo handling vehicle as a working machine is shown, but in addition, construction machinery, civil engineering machinery, agricultural machinery, transportation and cargo handling machinery, aerial work vehicles, and the like. It goes without saying that the present invention is applicable.
[Brief description of the drawings]
FIG. 1 is a side view showing a working state of a working machine according to an embodiment of the present invention.
FIG. 2 is a view showing a movable cab and a double parallel link mechanism. FIG. 2 (a) shows a state where the cab is located at a home position, and FIG. b).
FIG. 3 is a drive hydraulic circuit diagram for driving a work implement and a double parallel link mechanism.
[Explanation of symbols]
1 Working machine
6 work machine
7 cab
16 Boom cylinder
17 Arm cylinder
20 Double parallel link mechanism
21 1st parallel link
23 2nd parallel link
25 1st link cylinder
26 2nd link cylinder
31 engine
32 hydraulic pump
33 work machine operation circuit
34 Link operation circuit
36 Communication circuit
45 accumulator
48 Communication valve
50 Emergency operation switch

Claims (4)

A work machine comprising a hydraulic actuator for driving a driven body, wherein an accumulator is provided as a power source for supplying hydraulic oil to the hydraulic actuator. A first parallel link related to the extension / retraction operation of the driven body and a second parallel link related to the elevating operation of the driven body are connected in series, and the driven body is connected to a tip of the second parallel link. The working machine according to claim 1, wherein the hydraulic actuators are connected, and the hydraulic actuator includes a first link cylinder driving the first parallel link and a second link cylinder driving the second parallel link. The work machine according to claim 1, wherein the driven body is a cab. The oil passage connecting the hydraulic actuator and the accumulator is provided with a communication valve for opening and closing the oil passage, and an operation switch for operating switching of the communication valve is provided. Work machine.

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