JP6459610B2 - Boom interlock device for work vehicle - Google Patents

Description

  The present invention relates to a boom interlock device for a work vehicle in which the outrigger jack cannot be reduced when the boom is not retracted.

  There are crane work vehicles and aerial work vehicles as work vehicles using the boom. These work vehicles are operated by grounding the jacks of the left and right outriggers when working with the boom. At this time, the boom is retracted (falling down to a substantially horizontal posture) and the outriggers are retracted (reducing each jack).

  By the way, some boom work vehicles are designed to be able to run even when the boom is not retracted (for example, with the boom raised), but when the boom is not retracted, the boom tip is at a high position. Therefore, there is a risk that the boom may catch an overhead wire, a road sign, or the like if the work vehicle is driven without the boom being retracted.

  Therefore, in a known crane work vehicle, a boom interlock device is provided that prevents the outrigger jack from being reduced (and therefore the work vehicle cannot travel) when the boom is not retracted after the boom is operated with the jack grounded. There is something to prepare.

  As a work vehicle equipped with this kind of boom interlock device, for example, there is one shown in Japanese Patent Laid-Open No. 9-249386 (Patent Document 1). The boom interlock device equipped in the work vehicle of this known example (Patent Document 1) is detected from the hydraulic pump by a detection signal for detecting the jack reduction operation when the jack of the outrigger is reduced when the boom is not retracted. The hydraulic oil is unloaded to the tank side, thereby preventing the jack cylinder from being reduced. As a result, the work vehicle cannot travel in a state in which the boom is not retracted after the boom operation is completed.

  By the way, in the boom interlock device of the above-mentioned patent document 1, two electric switches are used to detect that the operation switching valves of the left and right jack cylinders (referred to as jack expansion / contraction operation switching valves) are operated to the jack reduction side. Is used, and the unloading valve provided in the unloading circuit is opened when either of the two electric switches is detected in the boom unfolded state and the jack contraction side operation of the jack expansion / contraction operation switching valve is detected. The valve is operated (hydraulic oil is unloaded).

Japanese Patent Laid-Open No. 9-249386

  However, in the boom interlock device disclosed in Patent Document 1, two electrical switches corresponding to the left and right jacks are used to detect the jack contraction side operation of the jack expansion / contraction operation switching valve. In the case of using an electrical switch, two switches are required and each actuator for operating each switch is required, so that there is a problem that the cost of parts becomes expensive.

  Therefore, the present invention can provide an inexpensive boom interlock mechanism by detecting that the outrigger jack has been operated to the reduction side with a simple configuration as a boom interlock device for a work vehicle. It was made for the purpose of making it.

  The present invention has the following configuration as means for solving the above problems. Although the present invention is directed to a boom interlock device for a work vehicle, in the following description, the present invention is sometimes simply referred to as a “boom interlock device”.

  The boom interlock device according to the present invention includes a pair of left and right outriggers that are on the left and right sides of the vehicle body and can support the vehicle body by extending a jack, a work machine having a boom mounted on the vehicle body, and left and right outriggers. Two sets of jack operating levers for individually extending and retracting each jack of the jacks, and detecting means for detecting that each jack operating lever is operated to the jack reduction side, the boom is in an unfolded state, and the detecting means When the jack reduction side operation by the jack operation lever is detected, the reduction operation of each jack is prohibited.

  In the boom interlock device of the present invention, the detecting means is directly pressed by each jack operating lever when either one of the two sets of jack operating levers is operated to the jack reducing side, A single actuating body that operates at the operation detecting position, and a single actuating body detector that detects that the operating body is operating at the jack reduction side operation detecting position and issues a detection signal thereof. It is characterized by being composed.

  The above operating body is a single one, and when either one of the two sets of jack operation levers is operated to the jack reduction side, each jack operation lever is directly pressed to reach the jack reduction side operation detection position. It works.

  The operating body detector is a single detector, and for example, a limit switch or a proximity switch can be used. And this operating body detector is good to employ | adopt what is turned ON by this operating body, when the said operating body is act | operating to the jack reduction side operation detection position.

  The boom non-storage state can be detected by an existing boom storage detector (for example, a limit switch or a proximity switch). In addition, it is good to employ | adopt this boom storage detector which is set to ON when a boom is not stored, and is OFF when a boom is stored.

  In the boom interlock device of the present application, the operating body detector is ON (the operating body operating at the jack reduction side operation detection position is detected) when the boom is not stored (the boom storage detector is ON). ), The unloading valve in the hydraulic circuit is opened (operating oil is unloaded).

  The boom interlock device according to the present invention is a detection means for detecting that each of the jack operation levers is operated to the jack reduction side in the case where the hydraulic oil is unloaded when the jack reduction operation is performed when the boom is not retracted. A single actuating body that is directly pressed by each jack operating lever when operated to any one of the jack operating levers to operate at the jack reducing side operation detection position; and A device having a single operating body detector for detecting that the jack is operating at the jack reduction side operation detection position is adopted.

  Therefore, in the boom interlock device of the present invention, common detecting means (mechanically actuating actuating body and actuating body detector for detecting the actuating action) for detecting the jack reducing side operation by each jack operating lever is used. Therefore, there is an effect that the boom interlock device can be manufactured at a low cost as compared with the boom interlock device (electric type) of the above-described known example.

It is a side view of a work vehicle equipped with a boom interlock device of an embodiment of the present application. FIG. 2 is a hydraulic circuit diagram of the work vehicle of FIG. 1 (including an electric circuit that operates an unload valve). It is a disassembled perspective view of the principal part in the boom interlock apparatus of the present-application Example with which the working vehicle of FIG. 1 was equipped. It is an assembly state top view of the boom interlock apparatus of FIG. 2, Comprising: It is explanatory drawing in a jack operation lever non-operation state (neutral state). It is an operation | movement change figure from FIG. 3, Comprising: It is explanatory drawing when a jack operation lever is operated to the reduction side.

[Example]
Hereinafter, the boom interlock device according to the present embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 shows a work vehicle equipped with the boom interlock device according to the present embodiment.

  In the embodiment of FIG. 1, a vehicle-mounted crane (so-called cargo crane) is employed as the work vehicle. However, in other embodiments, an aerial work vehicle can be employed as the work vehicle. In the following description, the work vehicle in FIG. 1 may be referred to as a crane work vehicle.

  The crane working vehicle in FIG. 1 is provided with a swivel post 21 that can be swiveled horizontally at a position closer to the front on the vehicle body frame 11 of the vehicle 1 (a space between the cabin and the torii at the front of the loading platform). A boom 22 that can be freely extended and retracted is attached to the base.

  The boom 22 is raised and lowered by the raising and lowering cylinder 23, and the boom 22 is in the boom retracted position as shown in FIG.

  Outriggers 3 and 3 are provided at a position closer to the front of the vehicle body 1 as a pair of left and right. The outriggers 3 and 3 are obtained by attaching jacks 31 and 31 to outer end portions of a slide cylinder that slides left and right outward with respect to the outer boxes 30 and 30, respectively.

  The expansion / contraction operation of each jack 31, 31 is performed individually by the two sets of jack operation levers 5, 5. As shown in FIG. 3, each of the jack operating levers 5 and 5 has a swing plate 52 attached to the base end portion of the lever bar 51 so as to be horizontally swingable by the support shaft 15, and attached to the swing plate 52. A protruding piece 53 is attached. A pair of lever rod 51 and protruding piece 53 are provided on both the left and right sides of the vehicle, and the left and right protruding pieces 53 are connected to each other by a connecting rod 54 so that the entire jack operating lever 5 is moved to the left and right. It can be operated from either side.

  As shown in FIG. 3, the jack operating levers 5 and 5 are respectively provided with support plates 14 attached to the upper and lower portions of the support column 13 erected on the upper surface of the outrigger outer box 30 (the lower support in FIG. 3). (Only the plate 14 is displayed) is supported by a support shaft 15 mounted in a vertical orientation while the lever bar 51 is operated to swing horizontally so that the protruding piece 53 swings in a horizontal plane. It has become.

  In the crane work vehicle shown in FIG. 1, each operation such as turning of the swing post 21, expansion and contraction of the boom 22, hoisting / lowering of a winch (not shown), and expansion / contraction of the jacks 31, 31 is performed by a hydraulic drive unit. This is done with an actuator. By the way, since the present application is directed to the boom interlock device, only the left and right jack cylinders 31A and 31B for expanding and contracting the left and right jacks are displayed as hydraulic actuators in the hydraulic circuit 4 of FIG. Is omitted.

  In the hydraulic circuit 4 shown in FIG. 2, reference numeral 40 is a hydraulic pump, 41 is a tank, 42 is a pump circuit to which hydraulic oil is supplied from the hydraulic pump 40, and 43 is a tank circuit connected to the tank 41.

  The left and right jack cylinders 31A and 31B can be expanded and contracted by operating the jack expansion / contraction operation switching valves 46A and 46B, respectively. The jack expansion / contraction operation switching valves 46A and 46B are switched to a neutral position, a contraction side position a, and an expansion side position b by swinging the jack operation levers 5 and 5, respectively.

  An unload circuit 44 is interposed between the pump circuit 42 and the tank circuit 43. The unload circuit 44 is provided with an unload valve 45 for functioning a boom interlock device described later. The unload valve 45 is a solenoid type valve that is opened when the electric circuit 7 described later is closed (the hydraulic oil is unloaded).

  The boom interlock device according to the embodiment of the present invention is configured so that each of the jack cylinders 31A and 31B (each jack 31) is operated when the boom is not retracted and either one of the two sets of jack operation levers 5 and 5 is operated to the jack reduction side. 31), the boom interlock device of this embodiment has the following configuration.

  First, the boom interlock device includes a boom retract detector 24 (FIGS. 1 and 2) that detects whether the boom 22 is in the retracted position or the unstored position, and each of the jack operation levers 5 and 5. On the other hand, a detecting means 6 (FIGS. 3 to 5) for detecting that the jack has been operated to the reduction side is provided.

  As the boom retract detector 24, a proximity switch or a limit switch can be used. In addition, the switch of the code | symbol 24 in FIG. 2 is a boom storage detector.

  The boom retract detector 24 is OFF (open) as shown in FIG. 2 in the boom retracted position (state shown in FIG. 1), while it is ON (closed) when the boom is not retracted (boom upright state). Yes).

  As shown in FIGS. 3 to 5, the detection means 6 detects a single operating body 61 that directly presses (oscillates) by a reduction operation of the jack operating lever 5 and an operating position of the operating body 61. And a single actuator detector 68.

  As shown in FIG. 3, the operating body 61 has a shaft hole 62 at a substantially central position of the elongated flat plate 61a, and an upright piece 63 having a predetermined height on one end side of the elongated flat plate 61a with the shaft hole 62 interposed therebetween. The other end side of the elongated flat plate 61a is used as an operation unit 64 for turning on / off the operating body detector 68. The operating body 61 is set so that it can rotate horizontally around the support shaft 15 by inserting the support shaft 15 through the shaft hole 62 at a position near the upper surface of the support plate 14. ing.

  The actuating body 61 is urged counterclockwise by a spring 66. A stopper piece 65 provided on the elongated flat plate 61a of the actuating body 61 abuts against the side edge of the support plate 14, and The operating body 61 is stopped at a predetermined position (a position where the operating body detector 68 is closed) shown in FIG.

  The protruding pieces 53 and 53 of the two sets of jack operation levers 5 and 5 are assembled in a stacked state at a position close to the upper surface of the elongated flat plate 61a of the operating body 61. In this assembled state, FIG. As shown in FIG. 5, the protruding pieces 53 and 53 are within the height range of the rising piece 63 of the operating body 61, and the side edges of the protruding pieces 53 and 53 are close to the side surface of the rising piece 63, respectively. Has been placed.

  Then, when both the jack operation levers 5 and 5 are in the neutral position (including the extension operation position), the operating body 61 has the protruding pieces 53 and 53 raised from the operating body 61 as shown in FIG. When the operating body 61 is held at a position where it is not pressed against the piece 63 and stopped by the stopper piece 65, when either one of the jack operating levers 5 and 5 is operated to the reduction operation position, FIG. As shown in FIG. 5, the projecting piece 53 directly presses the rising piece 63 of the operating body 61 to swing and displace the operating body 61 in the clockwise direction. The swing displacement position of the operating body 61 shown in FIG. 5 is the jack reduction side operation detection position in the claims.

  As the operating body detector 68, a proximity switch or a limit switch can be used. As shown in FIGS. 3 to 5, the operating body detector 68 is attached to the upper surface of the support plate 14 in an exposed state, and the operating body 61 is operated at a position immediately above the operating body detector 68. Whether or not the part 64 is located is detected. The operating body detector 68 corresponds to the switch denoted by reference numeral 68 in FIG.

  When the operating unit 64 of the operating body 61 is in the detection position as shown in FIG. 4, the operating body detector 68 is turned off (opened) as shown in FIG. 2, while as shown in FIG. When the operating portion 64 of the operating body 61 is in the non-detection position (jack reduction side operation detection position), it is set to be ON (closed).

  In FIG. 2, the boom storage detector 24 and the operating body detector 68 are incorporated in the electric circuit 7 in series. When both detectors 24 and 68 are turned on, the solenoid of the unload valve 45 is excited to open the unload valve 45.

  The boom interlock device of the present embodiment operates as follows.

  First, in the boom retracted state (the switch 24 in FIG. 2 is OFF), the electric circuit 7 is opened regardless of the operation state of the jack operation levers 5 and 5, so the unload valve 45 is maintained in the closed state. Accordingly, the jack cylinders 31A and 31B can be expanded and contracted.

  Next, even when the boom is not retracted (the boom retract detector 24 in FIG. 2 is ON), when neither of the jack operation levers 5 and 5 is operated to reduce, the operating body detector 68 as shown in FIG. 2 detects the operation unit 64 of the operating body 61, the switch 68 in FIG. 2 is kept OFF, and the electric circuit 7 is opened (the unload valve 45 is kept closed). Therefore, in this case, the expansion / contraction operation of each jack cylinder 31A, 31B is possible as described above.

  When the boom retracted state (the boom retracted detector 24 in FIG. 2 is ON) and any one of the jack operating levers 5 and 5 is operated to the jack contracting side, the operating body as shown in FIG. When the detector 68 does not detect the operation part 64 of the operating body 61, the switch 68 of FIG. 2 is turned ON, the electric circuit 7 is closed, the solenoid of the unload valve 45 is excited, and the unload valve 45 is Open the valve. Therefore, even if the jack operation lever 5 is operated to the jack reduction side, the reduction operation of each of the jack cylinders 31A and 31B does not occur (the grounding plate of each jack remains grounded and the work vehicle does not enter the traveling posture).

  In this case, the operator can recognize that the boom is not retracted because the jacks 31, 31 are not contracted, and thereafter, a predetermined procedure (reducing the jack after performing the boom retracting operation) is performed. By doing so, the work vehicle can be brought into a travelable state.

  The boom interlock device of the present embodiment has the following effects.

  That is, in the boom interlock device of this embodiment, any one of the jack operation levers 5 and 5 is used as the detection means 6 for detecting that the jack operation levers 5 and 5 are operated to the jack reduction side. A single actuating body 61 that is directly pressed by each jack operation lever when actuated to operate to the jack reduction side operation detection position, and the operation body 61 is actuated to the jack reduction side operation detection position. The thing with the single operation body detector 68 which detects this is employ | adopted. That is, the detection means 6 used in this embodiment is a common one for detecting the jack reduction side operation by the jack operation levers 5 and 5, respectively, and the operating body 61 and the detector 68 are each 1 It becomes the simple composition of each piece.

  Therefore, in the boom interlock device according to the embodiment of the present invention, the jack reduction side operation by the jack operating levers 5 and 5 is simply detected by the detecting means 6 (the operating body 61 that operates mechanically and the operating body detection that detects the operation). Therefore, the boom interlock device can be manufactured at a lower cost than the boom interlock device provided with two electric switches of the above-described known example.

  Note that as a boom interlock device according to another embodiment of the present application, an alarm (buzzer) may be issued when the electric circuit 7 in FIG. 5 is closed and the unload valve 45 is opened. Instead of opening the load valve 45, only an alarm may be issued.

  1 is a vehicle, 2 is a work machine, 3 is an outrigger, 4 is a hydraulic circuit, 5 is a jack operating lever, 6 is a detection means, 7 is an electric circuit, 22 is a boom, 24 is a boom retract detector, 31 is a jack, 31A , 31B is a jack cylinder, 40 is a hydraulic pump, 41 is a tank, 42 is a pump circuit, 43 is a tank circuit, 44 is an unload circuit, 45 is an unload valve, 46A and 46B are jack expansion / contraction operation switching valves, and 61 is operated The body 68 is a working body detector.

Claims (1)

A pair of left and right outriggers that can float and support the vehicle body by extending the jacks on the left and right sides of the vehicle body, a work machine having a boom mounted on the vehicle body, and each jack of each left and right outrigger individually Two sets of jack operating levers for extending and contracting, and detecting means for detecting that each of the jack operating levers is operated to the jack reduction side, the boom is in an unfolded state, and the detecting means is a jack by the jack operating lever. A boom interlock device for a work vehicle that prohibits a reduction operation of each jack when a reduction-side operation is detected,
The detection means is a single operation in which either one of the two sets of jack operation levers is operated to the jack reduction side operation detection position by being directly pressed by the respective jack operation levers when operated to the jack reduction side. And a single actuating body detector that detects that the actuating body is operating at a jack reduction side operation detection position and emits a detection signal thereof.
A boom interlock device for a work vehicle.

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