JP2006045955A - Safety device of construction machinery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safety device of construction machinery capable of raising safety in a state to tilt up an operator's cab in the construction machinery equipped with a structure enabling the operator's cab to tilt up. <P>SOLUTION: A rotary switch 36 is provided between an ON position terminal of a key switch 85 and a holding solenoid 84b of a stop solenoid 84a, one end of the rotary switch 36 is connected to an ON position terminal of the key switch 85 through a fuse 91, and the other end is connected to the holding solenoid 84b of the stop solenoid 84a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a safety device for a construction machine such as a hydraulic excavator having a structure that supports a driver's cab so that the driver's cab can be tilted forward with respect to a revolving frame and allows the cab to be tilted up.

  As a construction machine such as a hydraulic excavator having a structure that allows the cab to be tilted up with respect to the turning frame, for example, a machine described in Japanese Patent Application Laid-Open No. 2001-39352 is known. By tilting up the cab in this way, it is easy to maintain components that are hidden on the bottom side of the normal cab floor, hydraulic equipment housed in the swivel frame body under the cab, wiring, etc. There is an advantage to become.

JP 2001-39352 A

  When the cab is tilted up and maintenance work is performed, in order to ensure safety, the maintenance worker normally performs the tilt up with the engine stopped.

  Maintenance work in a state where the cab is tilted up is usually performed by a maintenance worker having knowledge of the machine, and full attention is paid to safety. However, it cannot be said that there is no possibility that a person other than the maintenance worker gets into the cab and starts the engine with the cab tilted up. For this reason, it is desired to further improve safety in a state where the cab is tilted up.

  An object of the present invention is to provide a construction machine safety device capable of improving safety in a state in which the cab is tilted up in a construction machine having a structure capable of tilting up the cab. .

  (1) In order to achieve the above object, the present invention includes a traveling body, a revolving body, and a front work machine, and the revolving body includes a revolving frame and a cab, and the cab is on the front side with respect to the revolving frame. A safety device for a construction machine having a structure capable of tilting and supporting the driver's cab, and detecting means for detecting tilt-up of the driver's cab, and tilting of the driver's cab with the detector An operation prohibiting means for prohibiting the operation of the construction machine when an up is detected, and the detecting means for detecting the tilt-up of the cab is disposed near the tilt-up rotation center of the cab with respect to the turning frame. It shall be a rotary switch.

  Thus, by providing the detecting means for detecting the cab tilt-up and the operation prohibiting means for prohibiting the operation of the construction machine when the cab tilt-up is detected, the cab is tilted up. Since the operation of the construction machine is prohibited, the construction machine is not operated, and the safety when the cab is tilted up is improved.

  In addition, a rotary switch is used as a detecting means for detecting tilt-up of the driver's cab, and the rotary switch is arranged in the vicinity of the center of the driver's tilt-up rotation with respect to the turning frame, thereby reducing the installation space of the detecting means and the mechanism. It will be easy. Further, since the mechanism is simplified, the number of components is reduced, thereby reducing the number of failed components and improving the reliability.

  (2) In the above (1), preferably, the rotary switch is a normally closed switch, is in a normal state when the cab is not tilted up, and when the cab is tilted up, It shall be opened by the rotational force.

  As a result, when the cab is tilted up, the rotary switch contacts are forcibly dissociated and the rotary switch is turned off, so that the rotary switch contacts are welded together by oxidation, and only with the spring force. Even if the contact is not dissociated, the contact is opened and the rotary switch is turned off, improving safety.

  (3) In the above (1) or (2), preferably, the construction machine includes an engine, and the operation prohibiting means stops the engine when detecting a tilt-up of the cab. It shall be a means.

  Thereby, in a state where the cab is tilted up, the engine is stopped, so that the construction machine is not operated, and safety when the cab is in the tilt-up state is improved.

  In addition, even if the cab is tilted up with the engine running, the engine will stop, so if the control lever moves unexpectedly during the tilt-up operation, the construction machine can be prevented from operating suddenly, and safety is ensured. Will improve.

  (4) In the above (1) or (2), preferably, the construction machine is driven by a main hydraulic pump and pressure oil discharged from the main hydraulic pump, and drives the front work machine and the swivel body. A plurality of hydraulic actuators, a plurality of control valves for controlling the flow of pressure oil supplied from the main hydraulic pump to the plurality of hydraulic actuators, a pilot pump, and a pilot secondary using a discharge pressure of the pilot pump as a pilot primary pressure. A plurality of operation lever devices that generate a secondary pressure and switch the plurality of control valves, and the operation prohibiting means supplies the pilot primary pressure to the plurality of operation lever devices when the cab is tilted up. It is assumed that it is a means for blocking the transmission path.

  As a result, when the cab is tilted up, the transmission path of the pilot primary pressure is interrupted. Therefore, even if the operation lever is operated, the construction machine will not operate, and the safety when the cab is tilted up Improves.

  Even if the cab is tilted up with the engine running, the transmission path of the pilot primary pressure is cut off, so that the construction machine suddenly operates if the control lever moves unexpectedly during the tilt-up operation. Can be prevented and safety is improved.

  (5) In the above (1) or (2), preferably, the construction machine includes an engine and a starting unit for starting the engine, and the operation prohibiting unit detects a tilt-up of the cab. In addition, the starting means is disabled.

  Thereby, in the state where the cab is tilted up, the engine starting means is stopped, so that the engine cannot be started, and the safety when the cab is in the tilt-up state is improved.

  (6) In any one of the above (1) to (5), preferably, an auxiliary switch device connected in parallel to the rotary switch is provided, and the auxiliary switch device is in a state where the cab is tilted up. It shall be possible to cancel the operation prohibition state of the construction machine.

  Thereby, since the maintenance worker can operate the construction machine as necessary with the cab tilted up, the operation check can be performed with the cab tilted up.

  According to the present invention, since the operation of the construction machine is prohibited when the cab is tilted up, even if a person other than the maintenance worker gets into the cab and operates the operation lever, the front work machine does not move. Therefore, safety is improved when the cab is tilted up.

  When a maintenance worker performs maintenance work such as inspection, maintenance, or repair with the cab tilted up, the maintenance worker connects the auxiliary switch device to operate the construction machine, and the hydraulic equipment, electrical equipment It is possible to check the operation of products, engines, alternators, excavator control controllers, etc.

  In addition, a rotary switch is used as a detecting means for detecting tilt-up of the driver's cab, and the rotary switch is arranged in the vicinity of the center of the driver's tilt-up rotation with respect to the turning frame, thereby reducing the installation space of the detecting means and the mechanism. It will be easy. Further, since the mechanism is simplified, the number of components is reduced, thereby reducing the number of failed components and improving the reliability.

  Furthermore, since the rotary switch is a normally closed switch, the contact force is forcibly dissociated by the rotational force when the cab is tilted up, and the rotary switch is turned off. Even if the contact is not dissociated only by the force of the spring due to the oxidation, the contact is opened and the rotary switch is turned off, improving the safety.

  Embodiments of the present invention will be described below with reference to the drawings.

  A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a side view showing the overall structure of a small hydraulic excavator to which the safety device for a construction machine according to the present embodiment is applied. In the following description, the front side (right side in FIG. 1), rear side (left side in FIG. 1), right side (FIG. 1) of the worker when the operator is seated on the driver's seat in the state shown in FIG. The front side of 1 paper side and the left side (back side of the paper surface in FIG. 1) are simply referred to as front side, back side, right side, and left side.

  In FIG. 1, the hydraulic excavator includes a lower traveling body 1, an upper revolving body 2 that is turnably mounted on the upper portion of the lower traveling body 1, and a front work machine 3. The lower traveling body 1 is a right / left traveling hydraulic motor for driving driving wheels 10R and 10L (only 10R is shown in FIG. 1) rotatably supported near the rear ends of both right and left sides of the track frame 9. 11R and 11L (however, only 11R is shown in FIG. 1), and a blade 14 for soil removal that moves up and down by a hydraulic cylinder 13 for blades is provided on the front side of the track frame 9.

  The upper swing body 2 includes a swing frame 4 that forms a basic lower structure, a swing post 5 that is pivotally attached to the tip of the swing frame 4 around a vertical pin (not shown), and a swing frame. 4 includes a so-called cabin type cab 7 and an exterior cover 8 that covers most of the swivel frame 4 other than the cab 7. The swing post 5 is connected to a swing hydraulic cylinder 16 provided on the revolving frame 4 via a connection pin (not shown), and the swing post 5 extends and contracts in the vertical direction by expansion and contraction of the swing hydraulic cylinder 16. By rotating around the axis, the front work machine 3 swings to the right and left. The front work machine 3 includes a boom 17, an arm 18 that is rotatably connected to the boom 17, and a bucket 19 that is rotatably connected to the arm 18. The boom 17, the arm 18, and the bucket 19 are operated by a boom hydraulic cylinder 20, an arm hydraulic cylinder 21, and a bucket hydraulic cylinder 22, respectively. Inside the exterior cover 8 are an engine 77 (see FIG. 10 described later), a main hydraulic pump 76 (see FIG. 10 described later) driven by the engine 77, a pilot pump 75, and a fuel tank for storing fuel of the engine 77. 83 (see FIG. 10 to be described later), equipment such as a hydraulic oil tank (not shown) serving as a pressure oil source of the hydraulic pump 76 is accommodated.

  FIG. 2 is a side view showing the inside of the cab 7 of the small hydraulic excavator shown in FIG. A driver's seat 25 on which an operator sits is provided in the operator's cab 7. On the right and left sides of the driver's seat 25, a bucket / boom manual operation lever 26R (only 26L is shown in FIG. 2) and a swivel / arm A manual operation lever 26L is provided, and right and left traveling operation levers 29R and 29L (only 29L is shown in FIG. 2) are provided in front of the driver seat 25. On the right side of the driver's seat 25, a blade manual operation lever 27 for driving the blade hydraulic cylinder 13 and moving the blade 14 up and down is provided. A gate lock lever 28 is provided on the left side of the driver seat 25. The gate lock lever 28 opens and closes an operator's boarding / alighting passage and enables or disables the hydraulic pilot system in accordance with the opening / closing operation.

  The above-described small hydraulic excavator includes a tilt-up mechanism for enabling the cab 7 to be tilted up. FIG. 3 is an external perspective view showing the cab 7 of the small hydraulic excavator shown in FIG. 1 tilted up from the right front side. This figure shows a state in which the engine portion, tank cover portion, engine, fuel tank, hydraulic oil tank, battery, and the like of the outer cover 8 of the upper swing body 2 are removed to show the tilt-up mechanism. FIG. 4 is a side view showing the main part of the upper swing body 2 with the small hydraulic excavator removed from the exterior cover, engine, fuel tank, hydraulic oil tank, battery, etc. to show the tilt-up mechanism. FIG. 5 is a view showing a state where the cab 7 is tilted up with the cover and the like removed, as in FIG.

  3 to 5, reference numerals 53 and 60 denote a tilt support mechanism and a tilt drive mechanism of a tilt up mechanism for tilting up the cab 7, respectively.

  3 to 5, a bottom plate 56 on the revolving frame 4, a pair of vertical plates 57 erected on the bottom plate 56, a front beam 58 extending in the left-right direction on the front side of the vertical plate 57, and the bottom plate 56. And a support member 51 located at the rear part. The cab 7 includes a floor board 50 and a cab 15 provided on the floor board 50 so as to cover the periphery of the driver seat 25. The floor board 50 of the cab 7 is attached to the revolving frame 4 at the front edge portion via a tilt support mechanism 53 so as to be tiltable. A support base 59 is provided at the upper rear end portion of the support member 51, and a cab mounting plate 52 is provided at the lower rear end portion of the cab 15. The cab mounting plate 52 has a shape extending in the left-right direction, and is connected to the support base 59 with a bolt. By removing this bolt, the floor plate 50 can be tilted up.

  The tilt drive mechanism 60 is provided between the support member 51 on the turning frame 4 and the side plate 54 provided in the cab 7. FIG. 6 is an external perspective view showing the tilt drive mechanism 60 in an enlarged manner.

  The tilt drive mechanism 60 includes a mounting bracket 61, a guide rail 63, a screw shaft 64, and a moving member 65, and the base end of the guide rail 63 is attached to the mounting bracket 61 so as to be vertically rotatable by a connecting pin 62. The mounting bracket 61 is bolted to the support member 51 on the revolving frame 4 side. The guide rail 63 is for linearly guiding the moving member 65 between the base end side (mounting bracket 61 side) and the free end side. The screw shaft 64 is a rod-like body having a thread cut on the outer periphery, is provided between the rails of the guide rail 63, and is screwed into a screw hole 67 formed in the moving member 65. A distal end connecting plate 68 is provided on the free end side of the guide rail 63, and a screw shaft 64 is rotatably supported by the distal end connecting plate 68 via a thrust bearing. The other end of the screw shaft 64 is a free end. The moving member 65 is arranged so as to be movable between the rails of the guide rail 63, and the other end is inserted into a sleeve 55 attached to the side plate 54. In this state, the moving member 65 is screwed by a bolt 66 and is prevented from being pulled out. A hexagonal tool connecting portion 69 is provided on the tip end side of the screw shaft 64 and is fixed to the screw shaft 64. The tool connecting portion 69 can connect a screw tightening tool such as a wrench for fastening a bolt from the outside. Thereby, the screw shaft 64 can be rotationally driven with a wrench, and the screwed moving member 65 can be moved along the guide rail 63.

  3 to 6, when the cab 7 is tilted up, the bolts for mounting the support member 51 and the cabin mounting plate 52 are removed, and the tip of the screw shaft 64 of the tilt drive mechanism 60 is located. A wrench or the like is connected to the hexagonal tool connecting portion 69, and the screw shaft 64 is driven to rotate. Thereby, the moving member 65 moves along the guide rail 63 in the direction of arrow C shown in FIGS. 3 to 6, and the tilt drive mechanism 60 rotates upward about the connecting pin 62, and at the same time, the moving member The cab 7 including the side plate 54, the floor plate 50, etc. to which the 65 is attached can be tilted up from the tilting support mechanism 53 toward the upper side or the front side indicated by the arrow A direction in FIGS. It becomes possible.

  In this way, the maintenance worker can perform maintenance work such as inspection, maintenance, and repair in a state where the cab 7 is tilted up. After the various operations are completed, the screw shaft 64 is driven to rotate in the reverse direction with a wrench, so that the moving member 65 moves in the direction of arrow D shown in FIGS. The driver's cab 7 having the side plate 54, the floor plate 50, etc., which are rotated downward about the center 62 and simultaneously attached with the moving member 65, is shown in the direction of arrow B in FIGS. It is possible to tilt down in the downward direction shown. The maintenance operation can be completed by bolting the cabin mounting plate 52 to the support member 51.

Next, the safety device of the present invention will be described.
FIG. 7 is an enlarged view showing a portion of the tilting support mechanism 53 of the small hydraulic excavator. In FIG. 7, the floor plate side support beam 30 is attached to the front edge portion of the floor plate 50 of the cab 7 by bolts or welding, and the frame side support beam 40 is attached to the front edge portion of the front beam 58 of the swivel frame 4. It is attached by bolts or welding. The floor plate-side support beam 30 is an angle member having an L-shaped cross section, and includes a vertical plate portion 30a and a horizontal plate portion 30b. The frame side support beam 40 is a single flat plate. Two pairs of U-shaped floor-side bracket members 100 and 101 are attached to the lower surface of the horizontal plate portion 30 b of the floor-plate-side support beam 30. The bracket member 100 is attached to the lower surface of the horizontal plate member 30b by welding, and the bracket member 101 is attached to the lower surface of the horizontal plate member 30b by bolts 41a and 41b. A frame side bracket member 104 is attached to the upper surface of the frame side support beam 40 by bolts 45a and 45b, and a frame side bracket member 105 is attached by bolts 42a and 42b. The floor-side bracket members 100 and 101 and the frame-side bracket members 104 and 105 are connected by pins 102 and 103, whereby the cab 7 is supported to be tiltable with respect to the turning frame 4. The axial centers of the pins 102 and 103 constitute the tilt-up rotation center of the turning frame 4.

  The hydraulic excavator tilt support mechanism 53 as described above is provided with a rotary switch 36 as detection means for detecting tilt-up of the cab 7 which is one of the main components of the safety device according to the present embodiment. .

  FIG. 8 is an enlarged view showing a portion where the rotary switch 36 is mounted in the portion of the tilt support mechanism 53 shown in FIG.

  A mounting bracket 34 is attached to the vertical plate portion 30a of the floor plate side support beam 30 by bolts 46a and 46b. A rotary switch 36 is attached to the mounting bracket 34 with bolts 48. The mounting bracket 34 is connected to the mounting plate portion 34a with respect to the vertical plate portion 30a, the mounting plate portion 34a is connected to the mounting plate portion 34a via a raised portion 34c, and the mounting plate portion 34b to the rotary switch 36 is located at a different height from the mounting plate portion 34a. The mounting bracket 34 is attached to the vertical plate portion 30a of the floor plate side support beam 30 by bolts 46a and 46b at the mounting plate portion 34b.

  The rotary switch 36 includes a switch body 38 having a mounting plate portion 36a, and a rotary lever 37 rotatably attached to the switch body 38. The rotary switch 36 is attached to the mounting plate portion 36a by a bolt 48. It is attached to a mounting plate portion 34b of the mounting bracket 34. A wiring 39 extends from the switch body 38.

  The mounting position of the rotary switch 36 is determined by the height of the mounting plate portion 34b (the height of the upright portion 34c) and the position of the mounting plate portion 36a of the rotary switch 36. The rotary switch 36 sets the height and position as appropriate. Thus, the rotary switch 36 is arranged so that the rotation center of the rotary lever 37 coincides with the axial center of the pins 102 and 103 which are the tilt-up rotation centers of the cab 7 with respect to the turning frame 4, that is, the rotary switch 36 is tilted up. 103) and is mounted so as to be substantially coaxial.

  A stopper 35 is provided on the upper surface of the frame-side support beam 40 of the swivel frame 4 so as to face the rotation lever 37 and leave a predetermined gap from the rotation lever 37. The rotation lever 37 tilts the cab 7 up. And engages with the stopper 35. The stopper 35 is attached to the frame side support beam 40 by bolts 47a and 47b.

  FIG. 9 is a view showing the operating range of the rotary lever 37 of the rotary switch 36.

  The rotary switch 36 is a normally closed switch that closes the contact in a free state where the rotary lever 37 is not engaged with the stopper 35 (hereinafter referred to as a steady state as appropriate). The rotary lever 37 of the rotary switch 36 is a steady state where the stopper 35 does not contact. If the angle in the state is 0 °, the angle can be rotated in the range of 0 to 90 degrees. Further, the rotary switch 36 keeps the contact closed when the rotation lever 37 is in the rotation range of 0 ° to 10 ° ± 5 °, and is ON when the rotation angle of the rotation lever 37 is more than that. Is turned off.

  As a result of the above configuration, when the cab 7 is tilted up, the rotary lever 37 of the rotary switch 36 is engaged with the stopper 35 provided on the frame side support beam 40 of the front beam 58 of the revolving frame 4 and pushed. When the rotation angle exceeds the rotation range of 0 ° to 10 ° ± 5 °, the contact is opened and the rotary switch 36 is turned off. When the cab 7 is tilted down, the rotation lever 37 reduces the rotation angle by a spring provided inside the switch body 38 along with the tilt down, and when the rotation angle falls within the range of 0 to 10 ° ± 5 °, the rotary switch 36 is turned on, and then the rotation lever 37 is separated from the stopper 35 and the rotation lever 37 is in a steady state.

FIG. 10 is a view showing a hydraulic drive device of a small hydraulic excavator provided with the safety device for the construction machine of the present embodiment.
In FIG. 10, the hydraulic drive apparatus according to the present embodiment includes an engine 77 and a fuel tank 83. The fuel tank 83 is connected to a fuel line inside the engine 77 via a fuel supply path 82, and the engine 77 is provided with a stop solenoid 84a. When the stop solenoid 84a is not excited, the fuel line is in a closed state, and when the stop solenoid 84a is excited, the plunger inside the engine is pushed and the fuel line is opened.

  The hydraulic drive device includes a main hydraulic pump 76 and a hydraulic cylinder 80. The hydraulic cylinder 80 is representative of various actuators such as a boom hydraulic cylinder 20, an arm hydraulic cylinder 21, a bucket hydraulic cylinder 22, a swing hydraulic cylinder 16, a blade hydraulic cylinder 13, and the like. The hydraulic pump is simply driven by the engine 77 (prime motor).

  The hydraulic drive device includes a hydraulic pilot type control valve 70 that controls the flow rate of pressure oil supplied from the hydraulic pump 76 to the hydraulic cylinder 80, an operation lever device 71 that instructs the operation of the hydraulic drive device, and a pilot pump. 75.

  The operation lever device 71 includes an operation lever 81 and a pair of pressure reducing valves 72A and 72B that output an operation pilot pressure obtained by reducing the primary pilot pressure from the pilot pump 75 in accordance with the operation amount of the operation lever 81. . The operation lever 81 is representative of various levers such as the bucket / boom manual operation lever 26R, the swivel / arm manual operation lever 26L, and the blade manual operation lever 27 shown in FIG. The operation pilot pressure (secondary pilot pressure) is output by the pressure reducing valve 72A or 72B according to the displacement amount (operation amount), and this operation pilot pressure is guided to the pilot operation portion 70a or 70b of the control valve 70. As a result, the control valve 70 is switched, pressure oil from the hydraulic pump 76 is guided to the hydraulic cylinder 80, and the hydraulic cylinder 80 is driven.

  On the hydraulic line 73 between the pilot pump 75 and the pressure reducing valves 72A and 72B, there is provided an electromagnetic opening / closing valve 74 for communicating / blocking the hydraulic line 73. The electromagnetic opening / closing valve 74 includes a solenoid part 74a and a spring 74b. And can be switched between a communication position 74L and a blocking position 74R.

  FIG. 11 is a diagram showing the construction machine safety device of the present embodiment in an electric circuit together with the engine starting system.

  In FIG. 11, the engine start system includes a starter 78 for starting the engine 77, a battery 79, a key switch 85, a relay switch 86, and the stop solenoid 84a described above.

  The key switch 85 is connected to the battery 79 and can be switched between an OFF position, an ON position, and a START position.

  The stop solenoid 84a includes a holding solenoid 84b and a suction solenoid 84c. One end of the holding solenoid 84b is connected to the ON position terminal of the key switch 85 via the fuse 91 and the rotary switch 36, and the other end is connected to GND. ing. One end of the suction solenoid 84c is connected to the START position terminal of the key switch 85 via the fuse 92, and the other end is connected to GND.

  The relay switch 86 includes a switch part 86a and a solenoid part 86b, and the switch part 86a is turned on when a current flows through the solenoid part 86b. The input side of the solenoid part 86b has first and second terminals, the first terminal is connected to the ON position terminal of the key switch 85 via the fuse 91, and the second terminal is the START position of the key switch 85. The terminal and the fuse 92 are connected. The solenoid part 86b is also connected to GND. One end of the switch part 86 a is connected to the battery 79, and the other end is connected to the starter 78.

  The engine starting system as described above includes the rotary switch 36 and the solenoid part 74a of the electromagnetic on-off valve 74 described above as the safety device of the present embodiment, the auxiliary switch device 88, and the gate lock switch 89.

  The gate lock switch 89 and the solenoid part 74 a of the electromagnetic opening / closing valve 74 are connected to the ON position terminal of the key switch 85 through the fuse 90. The solenoid part 74a of the electromagnetic opening / closing valve 74 is also connected to GND. The gate lock switch 89 is interlocked with the gate lock lever 28 so that it opens when the gate lock lever 28 shown in FIG. 2 is operated to the raised position and closes when the gate lock switch 89 is operated to the lowered position.

  The rotary switch 36 is provided in a circuit between the ON position terminal of the key switch 85 and the holding solenoid 84b of the stop solenoid 84a. One end of the rotary switch 36 is connected to the ON position terminal of the key switch 85 via the fuse 91. The other end is connected to the holding solenoid 84b of the stop solenoid 84a.

  The auxiliary switch device 88 is a detachable switch means connected in parallel to the rotary switch 36 to the ON position terminal of the key switch 85 and the holding solenoid 84b of the stop solenoid 84a, and includes a switch 88A and a connector portion 88B. ing. A connector portion 87 is provided on the circuit side connecting the rotary switch 36, the key switch 85, and the holding solenoid 84b of the stop solenoid 84a. One of the two terminals of the connector portion 87 is connected to the key switch 85 via the fuse 91. The other end is connected to the holding solenoid 84b of the stop solenoid 84a. The connector portion 88B of the auxiliary switch device 88 can be attached to and detached from the connector portion 87.

  Next, the operation of this embodiment will be described.

  When the cab 7 is tilted down, the rotary lever 37 of the rotary switch 36 is not engaged with the stopper 35, and the rotary switch 36 is turned on (closed).

  When the key switch 85 is in the OFF position in this state, the holding solenoid 84b and the suction solenoid 84c of the stop solenoid 84a and the solenoid portion 86b of the relay switch 86 are not connected to the battery 79, and the stop solenoid 84a is in a non-excited state, the fuel line inside the engine connected to the fuel supply path 82 is closed, the switch part 86a of the relay switch 86 is OFF, and the starter 78 is stopped. Regardless of the position of the gate lock switch 89, the solenoid portion 74a of the electromagnetic valve 74 is also disconnected from the battery 79, the electromagnetic valve 74 is in the blocking position, and the hydraulic line 73 is blocked.

  When the key switch 85 is switched to the ON position in this state, the holding solenoid 84b of the stop solenoid 84a and the first terminal of the solenoid portion 86b of the relay switch 86 are connected to the battery 79, and the holding solenoid 84b and solenoid of the stop solenoid 84a are connected. A current flows through the portion 86b. However, in this state, the stop solenoid 84a and the switch portion 86a of the relay switch 86 are not operated yet.

  When the key switch 85 is set to the START position with the cab 7 tilted down, the suction solenoid 84c of the stop solenoid 84a and the second terminal of the solenoid portion 86b are further connected while the connection state at the ON position is maintained. A battery 79 is connected. As a result, the stop solenoid 84a is excited, the fuel line inside the engine 77 connected to the fuel supply path 82 is opened, the switch portion 86a of the relay switch 86 is turned on, and the starter 78 is activated. As a result, fuel is supplied from the fuel tank 83 to the engine 77, and the engine 77 is started.

  In this state, when the key switch 85 is returned to the ON position, the switch portion 86a of the relay switch 86 is turned OFF and the starter 78 is stopped. Further, the connection between the suction solenoid 84c of the stop solenoid 84a and the battery 79 is cut off, but the holding solenoid 84b is connected to the battery 79, so that the stop solenoid 84a is maintained in an excited state. For this reason, the engine 77 continues to rotate because it has already been started.

  At this time, if the gate lock lever 28 shown in FIG. 2 is in the lowered position, the gate lock switch 89 is turned on, so that the solenoid portion 74a of the electromagnetic on-off valve 74 is energized and the electromagnetic on-off valve 74 is in communication. At the position 74L, the hydraulic line 73 is communicated, and the construction machine becomes operable.

  From this state, when the gate lock lever 28 is moved to the raised position to interrupt the operation, the gate lock switch 89 is turned off, the energization of the solenoid part 74a of the electromagnetic on-off valve 74 is cut off, and the electromagnetic on-off valve 74 is turned off. Thus, the hydraulic line 73 is blocked and the construction machine becomes inoperable.

  When the cab 7 is tilted up, the tilt drive mechanism 60 described above is operated. At this time, when the cab 7 is tilted up, the rotary lever 37 of the rotary switch 36 is engaged with the stopper 35 to be pushed and rotated. When the rotation angle exceeds 10 ° ± 5 °, the rotary switch 37 36 is turned OFF. As a result, the connection between the ON position terminal of the key switch 85 and the holding solenoid 84b of the stop solenoid 84a is disconnected, and the holding solenoid 84b of the stop solenoid 84a is disconnected from the battery 79. Therefore, the stop solenoid 84a is switched to a non-excited state, the fuel line inside the engine 77 connected to the fuel supply path 82 is closed, and the engine 77 is stopped. For this reason, the hydraulic pump 76 and the pilot pump 75 driven by the engine 77 are also stopped, and the construction machine becomes inoperable.

  When the operation check is performed with the cab 7 tilted up, the connector part 88B of the auxiliary switch device 88 is attached to the connector part 87, and the switch 88A is turned ON. Thereby, the ON position terminal of the key switch 85 and the holding solenoid 84b of the stop solenoid 84a are connected again, and the holding solenoid 84b of the stop solenoid 84a is connected to the battery 79. In this state, when the maintenance worker again operates the key switch 85 to the START position, as described above, the engine 77 is started, and at the same time, the hydraulic pump 76 and the pilot pump 75 are driven by the engine 77, and the construction machine can be operated. Become.

  When tilting down the cab 7 from this state, first, the switch 88A of the auxiliary switch device 88 is turned OFF to disconnect the connection between the ON position terminal of the key switch 85 and the holding solenoid 84b of the stop solenoid 84a. 77 is stopped. Next, the auxiliary switch device 88 is removed, and the cab 7 is tilted down. When the cab 7 is tilted down, the rotation angle of the rotary lever 37 of the rotary switch 36 is reduced by the spring provided in the switch body 38. When the rotation angle becomes 10 ° ± 5 ° or less, the rotary switch 36 is turned on. Thereafter, the rotary lever 37 is separated from the stopper 35, and the rotary switch 36 is maintained in the ON state. In this state, when the maintenance worker again operates the key switch 85 to the START position, the engine 77 is started again, and at the same time, the hydraulic pump 76 and the pilot pump 75 are driven by the engine 77, and the construction machine can be operated.

  According to the present embodiment configured as described above, in a state where the cab 7 is tilted up, the fuel line inside the engine connected to the fuel supply path 82 is shut off. Even if the vehicle enters the driver's cab 7 and turns the key switch 85, the engine 77 does not start and the front work machine 3 does not move. Therefore, the safety in the state where the cab 7 is tilted up is improved.

  In addition, when a maintenance worker performs maintenance work such as inspection, maintenance, and repair with the cab 7 tilted up as described above, hydraulic equipment, electrical equipment, an engine 77, an alternator (not shown), and a shovel. In order to check the operation of a control controller (not shown) or the like, there are cases where it is desired to operate the construction machine while the cab 7 is held in the tilted-up state. In this case, the maintenance worker connects the auxiliary switch device 88, and turns the key switch 85 to the start position so that the fuel line inside the engine 77 connected to the fuel supply passage 82 in a state where the cab 7 is tilted up is connected. Since the engine 77 is opened and the engine 77 is started, the construction machine can be operated, and the operation check of the hydraulic equipment or the like can be performed.

  Further, even if the cab 7 is tilted up with the engine 77 running, the fuel line inside the engine 77 connected to the fuel supply path 82 is cut off and the engine 77 is stopped. Even if the operation lever 81 in the cab 7 moves unexpectedly, the front work machine 3 can be prevented from suddenly operating, and further safety can be secured.

  In the present invention, the rotary switch 36 is used as a detecting means for detecting the tilt-up of the cab 7, and the rotary switch 36 is arranged substantially coaxially with the rotation center of the cab 7 with respect to the turning frame 4. Thereby, the installation space for the detection means is small and the mechanism is simple. Further, since the mechanism is simplified, the number of components is reduced, thereby reducing the number of failed components and improving the reliability.

  Further, the rotary switch 36 is a normally closed switch, and the contact is forcibly dissociated by the rotational force when the cab 7 is tilted up, so that the rotary switch 36 is turned off. Even if the contacts are melted by oxidation and the contacts are not dissociated only by the force of the spring, the contacts are opened and the rotary switch 36 is turned off, improving the safety.

  A second embodiment of the present invention will be described with reference to FIG.

  FIG. 12 is a diagram showing the construction machine safety device of the present embodiment in an electric circuit together with the engine starting system. In the figure, members equivalent to those shown in FIG.

  In FIG. 12, the safety device of the present embodiment is provided with a rotary switch 36 and a solenoid part 74a of an electromagnetic on-off valve 74, an auxiliary switch device 88, and a gate lock switch 89.

  The rotary switch 36 is provided in a circuit between the gate lock switch 89 and the solenoid part 74a of the electromagnetic on-off valve 74. One end of the rotary switch 36 is connected to the gate lock switch 89, and the other end is the solenoid part of the electromagnetic on-off valve 74. 74a. The terminal of the gate lock switch 89 that is not connected to the rotary switch 89 is connected to the ON position terminal of the key switch 85 via the fuse 90. The other end of the solenoid portion 74a of the electromagnetic opening / closing valve 74 is connected to GND.

  The auxiliary switch device 88 is a detachable auxiliary switch unit connected in parallel to the rotary switch 36 to the gate lock switch 89 and the solenoid part 74a of the electromagnetic on-off valve 74, and includes a switch 88A and a connector part 88B. . A connector 87 is provided on the circuit side connecting the rotary switch 36, the gate lock switch 89, and the solenoid 74a. One of the two terminals of the connector 87 is connected to the gate lock switch 89, and the other is electromagnetically opened and closed. A solenoid 74a of the valve 74 is connected. The connector portion 88B of the auxiliary switch device 88 can be attached to and detached from the connector portion 87.

  One end of the holding solenoid 84 b of the stop solenoid 84 a is connected to the ON position terminal of the key switch 85 through the fuse 91. Other configurations are the same as those in the first embodiment.

  Next, the operation of this embodiment will be described.

  The operation when the cab 7 is in the tilt-down state is the same as in the first embodiment.

  After the engine 77 is started, when the cab 7 is tilted up with the key switch 85 in the ON position and the gate lock lever 28 in the lowered position, the rotary lever 37 of the rotary switch 36 is engaged with the stopper 35. When the rotation angle is over 10 ° ± 5 °, the rotary switch 36 is turned off. As a result, the connection between the ON position terminal of the key switch 85 and the solenoid part 74 a of the electromagnetic on-off valve 74 is disconnected, and the solenoid part 74 a of the electromagnetic on-off valve 74 is disconnected from the battery 79. For this reason, the electromagnetic on-off valve 74 is in the cutoff position 74R, the hydraulic line 73 is shut off, and the hydraulic drive device becomes inoperable. As a result, the construction machine becomes inoperable.

  When the operation check is performed with the cab 7 tilted up, the connector part 88B of the auxiliary switch device 88 is attached to the connector part 87, and the switch 88A is turned ON. Thereby, the ON position terminal of the key switch 85 and the solenoid part 74 a of the electromagnetic on-off valve 74 are connected again, and the solenoid part 74 a of the electromagnetic on-off valve 74 is connected to the battery 79. As a result, the electromagnetic on-off valve 74 is in the communication position 74L, the hydraulic line 73 is in communication, and the construction machine can be operated.

  When tilting down the cab 7 from this state, first, the switch 88A of the auxiliary switch device 88 is turned OFF to disconnect the connection between the ON position terminal of the key switch 85 and the solenoid part 74a of the electromagnetic on-off valve 74, The electromagnetic on-off valve 74 is set to the cutoff position 74R, the hydraulic line 73 is shut off, the auxiliary switch device 88 is then removed, and the cab 7 is tilted down. When the cab 7 is tilted down, the rotation angle of the rotary lever 37 of the rotary switch 36 is reduced by the spring provided in the switch body 38. When the rotation angle becomes 10 ° ± 5 ° or less, the rotary switch 36 is turned on. Thereafter, the rotary lever 37 is separated from the stopper 35, and the rotary switch 36 is maintained in the ON state. Thereby, the battery 79 and the solenoid part 74a of the electromagnetic on-off valve 74 are connected, the electromagnetic on-off valve 74 is in the communication position 74L, the hydraulic line 73 is in communication, and the construction machine can be operated.

  According to the present embodiment configured as described above, when the cab 7 is tilted up, the hydraulic line 73 is shut off, so that a person other than the maintenance worker gets into the cab 7 and operates the operation lever 81. Even if is operated, the front work machine 3 does not move. Therefore, the safety in the state where the cab 7 is tilted up is improved.

  Further, when a maintenance worker performs maintenance work such as inspection, maintenance, repair, etc. with the cab 7 tilted up as described above, hydraulic equipment, electrical equipment, an engine 77, an alternator (not shown), and a shovel. In order to check the operation of a control controller (not shown) or the like, there are cases where it is desired to operate the construction machine while the cab 7 is held in the tilted-up state. In this case, the maintenance worker connects the auxiliary switch device 88 so that the hydraulic line 73 is opened while the cab 7 is tilted up, so that the construction machine can be operated, and the operation of the hydraulic equipment, etc. A check can be made.

  Furthermore, even if the cab 7 is tilted up while the engine 77 is running, the hydraulic line 73 is cut off, so that the operation lever 81 in the cab 7 moves unexpectedly during the tilt up. The working machine 3 can be prevented from suddenly operating, and further safety can be secured.

  In the present invention, the rotary switch 36 is used as a detecting means for detecting the tilt-up of the cab 7, and the rotary switch 36 is arranged substantially coaxially with the rotation center of the cab 7 with respect to the turning frame 4. Thereby, the setting space of the detection means is small and the mechanism is simple. Further, since the mechanism is simplified, the number of components is reduced, thereby reducing the number of failed components and improving the reliability.

  Furthermore, since the rotary switch 36 is a normally closed switch, the contact is mechanically dissociated by the rotational force when the cab 7 is tilted up, and the rotary switch 36 is turned off. Even if the contacts are melted by oxidation and the contacts are not dissociated only by the force of the spring, the contacts are opened and the rotary switch 36 is turned off, improving the safety.

  In the above embodiment, the hydraulic line 73 is shut off to disable the hydraulic pilot system to disable the hydraulic drive, but the hydraulic drive may be disabled by another means. As another means, for example, it is conceivable to provide an unload valve in the discharge line of the main hydraulic pump 76, operate this unload valve, and drop the pump discharge oil into the tank.

  A third embodiment of the present invention will be described with reference to FIG.

  FIG. 13 is a diagram showing an electrical circuit of the construction machine safety device according to the present embodiment together with an engine starting system. In the figure, members equivalent to those shown in FIG.

  In FIG. 13, the safety device of the present embodiment includes a rotary switch 36 and a solenoid portion 74 a of an electromagnetic on-off valve 74, an auxiliary switch device 88, and a gate lock switch 89.

  The rotary switch 36 is provided in a circuit between the START position terminal of the key switch 85 and the solenoid portion 86b of the relay switch 86. One end of the rotary switch 36 is connected to the START position terminal of the key switch 85 via the fuse 92, The other end is connected to the solenoid portion 86 b of the relay switch 86.

  The auxiliary switch device 88 is a detachable auxiliary switch unit connected in parallel to the rotary switch 36 to the START position terminal of the key switch 85 and the solenoid portion 86b of the relay switch 86, and includes a switch 88A and a connector portion 88B. ing. A connector portion 87 is provided on the circuit side connecting the rotary switch 36, the key switch 85, and the solenoid portion 86b. One of the two terminals of the connector portion 87 is connected to the START position terminal of the key switch 85 via the fuse 92. The other end is connected to the solenoid part 86 b of the relay switch 86. The connector portion 88B of the auxiliary switch device 88 can be attached to and detached from the connector portion 87.

  One end of the holding solenoid 84 b of the stop solenoid 84 a is connected to the ON position terminal of the key switch 85 through the fuse 91. Other configurations are the same as those in the first embodiment.

  Next, the operation of this embodiment will be described.

  The operation when the cab 7 is in the tilt-down state is the same as in the first embodiment.

  When the cab 7 is tilted up with the key switch 85 in the START position, the engine 77 is started, the key switch 85 in the ON position, and the gate lock lever 28 in the lowered position, the rotary switch 36 The rotation lever 37 is engaged with the stopper 35 and is pushed and rotated. When the rotation angle exceeds 10 ± 5 °, the rotary switch 36 is turned off. As a result, the connection between the START position terminal of the key switch 85 and the solenoid portion 86 b of the relay switch 86 is disconnected, and the solenoid portion 86 b of the relay switch 86 is disconnected from the battery 79. For this reason, the switch part 86a of the relay switch 86 is turned off, the starter 78 and the battery 79 are not connected, and the starter 78 cannot be started. In this state, even if the maintenance worker stops the engine 77 and operates the key switch 85 to the START position again, the starter 78 is not started and the engine 77 cannot be started. As a result, the hydraulic pump 76 and the pilot pump 75 driven by the engine 77 are not started, and the construction machine becomes inoperable.

  When the operation check is performed with the cab 7 tilted up, the connector part 88B of the auxiliary switch device 88 is attached to the connector part 87, and the switch 88A is turned ON. As a result, the START position terminal of the key switch 85 and the solenoid portion 86 b of the relay switch 86 are connected, and the solenoid portion 86 b of the relay switch 86 is connected to the battery 79. As a result, the switch portion 86a of the relay switch 86 is turned on, and the starter 78 can be activated. Even if the maintenance worker stops the engine 77 in this state, the engine 77 can be started by operating the key switch 85 to the START position again. As a result, the hydraulic pump 76 and the pilot pump 75 driven by the engine 77 are also activated, and the construction machine can be operated.

  When tilting down the cab 7 from this state, first, the switch 88A of the auxiliary switch device 88 is turned OFF, the connection between the START position terminal of the key switch 85 and the solenoid portion 86b of the relay switch 86 is disconnected, and the switch portion. 86a is turned off and the starter 78 is disabled. Next, when the auxiliary switch device 88 is removed and the cab 7 is tilted down, the rotation angle of the rotary lever 37 of the rotary switch 36 is reduced by a spring provided in the switch body 38, and the rotation angle is 10 ° ± 5 °. The rotary switch 36 is turned on when it becomes below, and then the rotary lever 37 is separated from the stopper 35 and the rotary switch 36 is kept in the ON state. In this state, when the maintenance worker stops the engine 77 and operates the key switch 85 to the START position again, the engine 77 is started again, and the hydraulic pump 76 and the pilot pump 75 driven by the engine 77 are also started and construction is performed. The machine is ready for operation.

  According to the present embodiment configured as described above, when the cab 7 is tilted up, the starter 78 is stopped, so that a person other than the maintenance worker gets into the cab 7 and presses the key switch 85. Even if it is turned, the engine 77 does not start and the front work machine does not move. Therefore, the safety in the state where the cab 7 is tilted up is improved.

  Further, when a maintenance worker performs maintenance work such as inspection, maintenance, repair, etc. with the cab 7 tilted up as described above, hydraulic equipment, electrical equipment, an engine 77, an alternator (not shown), and a shovel. In order to check the operation of a control controller (not shown) or the like, there are cases where it is desired to operate the construction machine while the cab 7 is held in the tilted-up state. In this case, since the maintenance worker connects the auxiliary switch device 88 and turns the key switch 85 to the start position, the starter 78 is started with the cab 7 tilted up and the engine 77 is started. Can be operated, and operation checks of hydraulic equipment and the like can be performed.

  In the present invention, the rotary switch 36 is used as a detecting means for detecting the tilt-up of the cab 7, and the rotary switch 36 is arranged substantially coaxially with the rotation center of the cab 7 with respect to the turning frame 4. Thereby, the installation space for the detection means is small and the mechanism is simple. Further, since the mechanism is simplified, the number of components is reduced, thereby reducing the number of failed components and improving the reliability.

  Furthermore, since the rotary switch 36 is a normally closed switch, the contact is mechanically dissociated by the rotational force when the cab 7 is tilted up, and the rotary switch 36 is turned off. Even if the bearing portion of the rotary lever 37 is deteriorated and difficult to rotate freely, the contact is opened and the rotary switch 36 is turned OFF, so that safety is improved.

  In the above embodiment, the rotary switch 36 is arranged so as to be substantially coaxial with the tilt-up rotation center of the cab 7 with respect to the turning frame 4. If so, it may be slightly deviated. In short, the rotary switch 36 only needs to be in a position where the tilt-up of the cab 7 can be detected in the vicinity of the rotation center of the tilt-up, and even if the rotary switch 36 is slightly deviated from the rotation center of the tilt-up, Can be made more compact and the mechanism can be simplified as compared with the case where the sensor is disposed at a place other than the tilt-up rotation center or when other sensors are used. When the rotary switch 36 is arranged coaxially with the rotation center of the tilt-up, the rotation angle of the tilt-up when the rotary lever 37 of the rotary switch 36 is pushed by the stopper and the rotation angle of the rotary switch 36 are the same. On the other hand, when the rotary switch 36 is shifted from the rotation center of the tilt-up 36, the rotation angle of the rotary switch 36 with respect to the rotation angle of the tilt-up when the rotation lever 37 of the rotary switch 36 is pushed by the stopper. Is different. Therefore, in order to use this effect, it is conceivable that the rotary switch 36 is positively shifted from the tilt-up rotation center. For example, by extending the upright portion 34c of the mounting bracket 34 to which the rotary switch 36 is attached, the rotary shaft of the rotary switch 36 is moved away from the vertical plate portion 30a of the floor plate side support beam 30 with respect to the tilt-up rotation center. When arranged, the rotation angle of the rotary switch 36 is larger than the rotation angle of tilt-up, and therefore the angle at which the rotary switch 36 is turned off can be substantially advanced to improve detection sensitivity.

  In the above embodiment, the detachable switch means 88 is provided as an auxiliary switch device connected in parallel to the rotary switch. However, a permanent switch may be arranged at a place where maintenance workers can manage. Good.

It is a side view showing the whole structure of the small hydraulic excavator which is the application object of the safety device of the construction machine of the present invention. It is a side view showing the inside of the cab of the small hydraulic excavator which is the application object of the safety device of the construction machine of the present invention. Tilt up the cab with the small hydraulic excavator to which the safety device of the construction machine of the present invention is applied removed the exterior cover, engine, fuel tank, hydraulic oil tank, battery, etc. to show the tilt up mechanism It is an external appearance perspective view which shows the state which carried out from the right front side. A small hydraulic excavator to which the safety device for a construction machine according to the present invention is applied is in a state in which an outer cover, an engine, a fuel tank, a hydraulic oil tank, a battery, and the like are removed to show a tilt-up mechanism, and It is a side view which shows a part. Tilt up the cab with the small hydraulic excavator to which the safety device of the construction machine of the present invention is applied removed the exterior cover, engine, fuel tank, hydraulic oil tank, battery, etc. to show the tilt up mechanism It is a side view which shows the state which carried out. It is an external appearance perspective view which expands and shows the tilting mechanism of the small hydraulic shovel which is the application object of the safety device of the construction machine of this invention. It is a figure which expands and shows the tilting support mechanism of the small hydraulic shovel which is the application object of the safety device of the construction machine of this invention. It is a figure which expands and shows the attachment part of a rotary switch among the tilting support mechanisms shown in FIG. It is a figure which expands and shows the surface in which the switch part of the rotary switch of the safety device of the construction machine of this invention was provided. It is a figure which shows the hydraulic drive device of the small hydraulic excavator which is the application object of the safety device of the construction machine of this invention. It is a figure which shows the safety device of the construction machine which is the application object of the 1st Embodiment of this invention with an electric circuit with an engine starting system. It is a figure which shows the safety device of the construction machine which is the application object of the 2nd Embodiment of this invention with an electric circuit with an engine starting system. It is a figure which shows the safety device of the construction machine which is the application object of the 3rd Embodiment of this invention by an electric circuit with an engine starting system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper revolving body 3 Front work machine 4 Turning frame 7 Driver's cab
36 Rotary switch 70 Control valve 74 Electromagnetic switching valve 75 Pilot pump 76 Hydraulic pump 77 Engine 78 Starter 79 Battery 80 Hydraulic cylinder 81 Operation lever 83 Fuel tank 84 Stop solenoid 85 Key switch 86 Relay switch 88 Auxiliary switch device 89 Gate lock switch

Claims (6)

A traveling body, a revolving body, and a front working machine are provided. The revolving body includes a revolving frame and a cab, and the cab can be tilted forward with respect to the revolving frame, and the cab can be tilted up. In a construction machine safety device with a structure
Detecting means for detecting tilt-up of the cab;
An operation prohibiting means for prohibiting the operation of the construction machine when the detection means detects a tilt-up of the cab.
A safety device for a construction machine, wherein the detection means for detecting tilt-up of the cab is a rotary switch disposed in the vicinity of the tilt-up rotation center of the cab with respect to the turning frame. The safety device for a construction machine according to claim 1,
The rotary switch is a normally closed switch, is in a normal state when the cab is not tilted up, and is opened by the rotational force at the time when the cab is tilted up. Machine safety device. The safety device for a construction machine according to claim 1 or 2,
The construction machine includes an engine, and the operation prohibiting unit is an engine stop unit that stops the engine when detecting a tilt-up of the cab. The safety device for a construction machine according to claim 1 or 2,
The construction machine is driven by a main hydraulic pump and pressure oil discharged from the main hydraulic pump, and a plurality of hydraulic actuators that drive the front working machine and the swivel body,
A plurality of control valves for controlling the flow of pressure oil supplied from the main hydraulic pump to the plurality of hydraulic actuators;
A pilot pump,
A plurality of operation lever devices for generating a pilot secondary pressure using the discharge pressure of the pilot pump as a pilot primary pressure and switching the plurality of control valves;
A construction machine safety device characterized in that the operation prohibiting means is means for blocking a path for transmitting the pilot primary pressure to the plurality of operation lever devices when the cab tilts up. The safety device for a construction machine according to claim 1 or 2,
The construction machine includes an engine and starting means for starting the engine,
A construction machine safety device characterized in that the operation prohibiting means disables the starting means when detecting a tilt-up of the cab. In the safety device of the construction machine in any one of Claims 1-5,
An auxiliary switch device connected in parallel to the rotary switch, the auxiliary switch device being capable of canceling the operation prohibition state of the construction machine with the cab tilted up. Safety device.

Images