JP2014069914A - Extension state monitoring device for outrigger jack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extension state monitor device capable of setting an outrigger jack in a proper elongation state.SOLUTION: An extension state monitoring device for an outrigger jack comprises: load measuring means 81 for measuring a load applied to an outrigger jack 26; control means 70 for receiving input of the measurement result of the load measuring means 81; and warning means 82 connected to the control means 70. The control means 70 decides, when the load measured by the load measuring means 81 does not vary, that the outrigger jack 26 is in an over-extended state, and operates the warning means 82. The control means can detect that the wheels of a working vehicle have floated, and issues a warning when the outrigger jack 26 is in an over-extended state, so that the outrigger jack 26 can be shrunken to a proper extended state.

Description

  The present invention relates to an extension state monitoring device for an outrigger jack. More specifically, the present invention relates to an extension state monitoring device for setting an outrigger jack to an appropriate extension state.

  As shown in FIG. 6, the loading-type truck crane 1 in which the small crane 20 is mounted on the general-purpose truck 10 includes only two outrigger jacks 26 on each of the left and right sides of the vehicle (for example, Patent Document 1). ). It is appropriate that the outrigger jack 26 of such a load-type truck crane 1 extends to such an extent that the front wheel 14 of the general-purpose truck 10 is lightly grounded. When the outrigger jack 26 is extended until the front wheel 14 is lifted, if the boom 23 is turned to the front of the general-purpose truck 10 and is overloaded, the general-purpose truck 10 suddenly becomes like a seesaw with the outrigger jack 26 as a fulcrum. Inclined forward, the front wheel 14 comes into contact with the ground, and the rear wheel is lifted and becomes unstable. On the other hand, when the front wheel 14 is lightly grounded, the load can be supported by the front wheel 14 even in the case of an overload, and the general-purpose truck 10 tilts gently forward as the suspension sinks. Therefore, it is possible for the worker to notice the overload and cope with the load reduction.

  As described above, it is necessary to set the outrigger jack 26 to an appropriate extended state. However, since the extension work of the outrigger jack 26 is conventionally left to the operator's operation, when a worker who does not know the proper extension state, such as a user of a rental machine, operates the outrigger jack 26, the front wheel There was a problem that it extended | stretched until 14 floated.

JP-A-11-106184

  In view of the above circumstances, an object of the present invention is to provide an extended state monitoring device that can set an outrigger jack to an appropriate extended state.

An extension state monitoring device for an outrigger jack according to a first aspect of the present invention comprises a load measuring means for measuring a load applied to the outrigger jack, and a control means for inputting a measurement result of the load measuring means. When the load measured by the load measuring means no longer changes, it is determined that the outrigger jack is in an over-extended state.
An extension state monitoring device for an outrigger jack according to a second aspect of the present invention comprises the alarm means connected to the control means in the first aspect, wherein the control means determines that the outrigger jack is in an overextension state. The alarm means is actuated.
According to a third aspect of the present invention, there is provided the outrigger jack extension state monitoring device according to the first aspect, wherein the control means contracts the outrigger jack by a predetermined length when it is determined that the outrigger jack is in an overextension state. And
According to a fourth aspect of the present invention, there is provided an outrigger jack extension state monitoring device comprising: a load measuring means for measuring a load applied to the outrigger jack; and a control means for inputting a measurement result of the load measuring means. The extension of the outrigger jack is stopped when the load measured by the load measuring means exceeds a threshold value.
According to a fifth aspect of the present invention, there is provided an outrigger jack extension state monitoring device comprising: a load measuring means for measuring a load applied to the outrigger jack; and a control means for inputting a measurement result of the load measuring means. The extension of the outrigger jack is stopped when the rate of change of the load measured by the load measuring means exceeds a peak.
An outrigger jack extension state monitoring device according to a sixth aspect of the present invention comprises: a load measuring means for measuring a load applied to the outrigger jack; and a control means for inputting a measurement result of the load measuring means. The extension of the outrigger jack is stopped when the change rate of the load change rate measured by the load measuring means becomes a negative value.

According to the first invention, it is possible to detect that the wheel of the work vehicle is lifted by determining that the load applied to the outrigger jack does not change as an over-extended state. Therefore, the outrigger jack can be contracted and set to an appropriate extended state.
According to the second aspect of the invention, an alarm is issued when the outrigger jack is in the over-extended state, so that it is possible to prompt the worker to contract the outrigger jack.
According to the third invention, since the outrigger jack is contracted for a predetermined length after the outrigger jack is in the overextended state, the outrigger jack can be set in an appropriate extended state.
According to the fourth aspect, since the extension of the outrigger jack is stopped when the load exceeds the threshold value, the outrigger jack can be set to an appropriate extension state before the wheel of the work vehicle is lifted.
According to the fifth aspect, since the extension of the outrigger jack is stopped when the load change rate exceeds the peak, the outrigger jack can be set in an appropriate extension state before the wheel of the work vehicle is lifted.
According to the sixth invention, since the extension of the outrigger jack is stopped when the change rate of the load change rate becomes a negative value, the outrigger jack is set to an appropriate extension state before the wheel of the work vehicle floats. it can.

1 is a hydraulic circuit diagram of a load-type truck crane including an outrigger jack extension state monitoring device according to a first embodiment of the present invention. It is explanatory drawing of the expansion | extension state of an outrigger jack. It is a graph which shows the time change of the load concerning an outrigger jack. It is a flowchart of the process by a control means. (A) is a graph which shows the time change of the load concerning an outrigger jack, (b) is a graph which shows the time change rate of the load concerning an outrigger jack, (c) is the time change rate of the load concerning an outrigger jack. It is a graph which shows the time change rate of. It is a side view control means of a load-type truck crane.

Next, an embodiment of the present invention will be described with reference to the drawings.
The extension state monitoring device for an outrigger jack according to the present invention is provided in a work vehicle in which it is appropriate that the outrigger jack is extended to such an extent that the wheels are grounded. As such work vehicles, there are many work vehicles provided with one outrigger jack on each of the left and right sides of the vehicle such as a load-type truck crane. However, even if the work vehicle is provided with four or more outrigger jacks, the proper outrigger jack is suitable. If the work vehicle is in the extended state as described above, the extended state monitoring device for an outrigger jack according to the present invention can be employed.
In the following description, a load-type truck crane will be described as an example, but the same applies to other work vehicles.

First, the configuration of the loadable truck crane will be described.
As shown in FIG. 6, the load-type truck crane 1 includes a small crane 20 mounted on a vehicle frame 13 between a cab 11 and a loading platform 12 of a general-purpose truck 10.

  The small crane 20 includes a base 21 fixed on the vehicle frame 13, a post 22 provided so as to be rotatable with respect to the base 21, a boom 23 provided on an upper end portion of the post 22 so as to be raised and lowered, and a base 21. And a pair of outrigger devices 24, 24 provided on the left and right sides of the. The post 22 incorporates a winch. A wire rope is guided from the winch to the tip of the boom 23 and hung around the hook 27 via a pulley at the tip of the boom 23, whereby the hook 27 is attached to the tip of the boom 23. Hanging from the part. A lever group 28 for operating these is provided on both the left and right sides of the base 21.

  The outrigger device 24 includes an overhanging beam 25 fixed to the base 21 and an outrigger jack 26 fixed to the tip of the overhanging beam 25. At the start of work, the overhanging beam 25 is overhanged and the outrigger jack 26 is extended to ground the lower end float. Thereby, the stability of the loadable truck crane 1 is ensured. At the end of the work, the outrigger jack 26 is contracted, the extended beam 25 is retracted, and the outrigger device 24 is stored.

  As shown in FIG. 1, the hydraulic circuit of the loadable truck crane 1 mainly includes a hydraulic valve unit 31, a hydraulic pump 33 that supplies hydraulic oil in a tank 32 to the hydraulic valve unit 31, and a hydraulic valve unit 31. It is composed of a plurality of connected hydraulic actuators 34 to 37, 26, 26.

  The hydraulic actuator connected to the hydraulic valve unit 31 includes a boom expansion / contraction hydraulic cylinder 34 that expands and contracts the boom 23, a winch hydraulic motor 35 that winds and unwinds the hook 27, a boom hoisting hydraulic cylinder 36 that hoists the boom 23, and a post. 22 is a pair of outrigger jacks 26 and 26 constituted by a turning hydraulic motor 37 that turns 22 and a hydraulic cylinder.

  The hydraulic valve unit 31 is provided with switching control valves 41 to 46, to which hydraulic actuators 34 to 37, 26, and 26 are connected, respectively. The hydraulic actuators 34 to 37, 26, and 26 can be operated by controlling the direction and flow rate of the hydraulic oil supplied from the hydraulic pump 33 by the switching control valves 41 to 46.

  A lever is attached to each of the switching control valves 41 to 46, and the position of the spool can be switched by manually operating the lever. The levers attached to the switching control valves 41 to 46 are provided on the left and right sides of the base 21 as the lever group 28. Therefore, when the operator operates the lever group 28, the boom 23, the hook 27, and the outrigger jacks 26 and 26 can be operated.

  Further, pilot cylinders 51 to 56 are attached to the switching control valves 41 to 46, respectively, and the position of the spool can be switched by the operation of the pilot cylinders 51 to 56.

  Each of the pilot cylinders 51 to 56 is a double-acting cylinder, and is provided with an electromagnetic valve for supplying and discharging hydraulic oil to and from the right oil chamber and an electromagnetic valve for supplying and discharging hydraulic oil to and from the left oil chamber. . These solenoid valves are connected to the control means 70 and operate based on a control signal from the control means 70 to drive the pilot cylinders 51 to 56 and switch the spool positions of the switching control valves 41 to 46. It is like that.

  Position detection sensors 61 to 64 are attached to the pilot cylinders 51 to 54 attached to the switching control valves 41 to 44. These position detection sensors 61 to 64 can detect the spool positions of the switching control valves 41 to 44. Further, switching detection sensors 65 and 66 are attached to pilot cylinders 55 and 55 attached to switching control valves 45 and 46 for controlling the supply of hydraulic oil to the outrigger jacks 26 and 26, respectively. These switching detection sensors 65 and 66 can detect whether or not the switching control valves 45 and 46 are in a neutral position (a position at which the supply of hydraulic oil to the outrigger jacks 26 and 26 is stopped).

  The position detection sensors 61 to 64 and the switching detection sensors 65 and 66 are respectively connected to the control means 70, and the detection results are input to the control means 70.

(First embodiment)
The outrigger jack extension state monitoring device according to the first embodiment of the present invention is incorporated in the hydraulic circuit as described above.
Pressure sensors 81 and 81 are provided in the oil passages connected to the cap side oil chambers (extension operation side oil chambers) of the outrigger jacks 26 and 26, respectively. The pressure sensors 81 and 81 can measure the load applied to the outrigger jacks 26 and 26. The pressure sensors 81, 81 are connected to the control means 70, and the measurement results are input to the control means 70. The control means 70 is composed of a known computer or the like, and can perform processing for monitoring the extension state of the outrigger jacks 26 and 26 described later, in addition to the control of the hydraulic valve unit 31 described above. Further, a speaker 82 is connected to the control means 70, and an alarm can be issued by voice. The pressure sensor 81, the control means 70, and the speaker 82 constitute an outrigger jack extension state monitoring device according to this embodiment.

  The pressure sensor 81 corresponds to the load measuring means described in the claims. The load measuring means is not particularly limited as long as it can measure the load applied to the outrigger jack 26, and a strain gauge, a load cell, or the like may be used.

  A stability limit alarm device may be attached to the load-type truck crane 1 (for example, Patent Document 1). When the load-type truck crane 1 falls sideways, the supporting force of the outrigger jack 26 on the side opposite to the overturning direction is lowered prior to the fall, and the internal pressure of the cap side oil chamber of the outrigger jack 26 is lowered. The stability limit alarm device measures the internal pressure of the oil chamber on the cap side of the outrigger jack 26 with a pressure sensor, detects that the measured value is below a predetermined value, and uses this as the stability limit of the load-type truck crane 1. A warning is given by catching or buzzer. When such a stability limit alarm device is attached, the pressure sensor of the stability limit alarm device can be used as the load measurement means of the extension state monitoring device, and there is no need to newly provide a load measurement means.

The speaker 82 corresponds to alarm means described in the claims. The alarm means is not particularly limited as long as it can issue an alarm to the worker, and a lamp, a display display, or the like may be used.
Moreover, the control means 70 may implement | achieve the control function of the hydraulic valve unit 31, and the expansion | extension state monitoring function of the outrigger jacks 26 and 26 with the same apparatus, and implement | achieve these functions with a separate apparatus, You may comprise them so that communication is possible mutually.

Next, the time change of the load applied to the outrigger jack 26 when the outrigger jack 26 is extended will be described with reference to FIGS.
(1) Beginning of extension to grounding: AB
When the outrigger jack 26 is extended from the fully contracted state (FIG. 2 (1)), no load is applied until the float 26f at the lower end of the outrigger jack 26 contacts the ground, and the load remains constant at 0 ( (Between AB in FIG. 3).

(2) Grounding-Front wheel starts to float: BC
After the outrigger jack 26 is further extended and the float 26f is grounded (FIG. 2 (2)), as the outrigger jack 26 is extended, the load applied to the suspension of the front wheel 14 gradually moves to the outrigger jack 26, and the front wheel The load gradually increases until 14 begins to float (between B and C in FIG. 3). In this state, the outrigger jack 26 is extended to such an extent that the front wheel 14 comes in contact with the ground, and is in an appropriate extended state. In particular, it is preferable that the front wheel 14 is closer to the beginning of the front wheel lift (C) because the front wheel 14 is “lightly grounded”.

(3) Front wheel float: CD
After the outrigger jack 26 is further extended and the front wheel 14 is lifted (FIG. 2 (3)), all the load applied to the suspension of the front wheel 14 is transferred to the outrigger jack 26. The load is constant at a predetermined value (between CD in FIG. 3). In this state, the outrigger jack 26 is in a state (excessive extension state) in which it is extended more than appropriate.

  In the present embodiment, the control means 70 uses the hydraulic pressure measured by the pressure sensor 81 as a load applied to the outrigger jack 26, and determines that the outrigger jack 26 is in an over-extended state when the load does not change over time. To do. The hydraulic pressure measured by the pressure sensor 81 and the load applied to the outrigger jack 26 are proportional.

  When the outrigger jack 26 determines that the outrigger jack 26 is in the over-extended state, the control means 70 issues an audio alarm from the speaker 82. For example, inform the worker of specific measures such as "The front wheel is floating. Please retract the outrigger jack until the front wheel is lightly touched."

More specifically, the control means 70 determines an overextension state by the following procedure and issues a sound alarm.
As shown in FIG. 4, the control means 70 first determines whether or not the outrigger jack 26 is being operated based on the detection result of the switching detection sensor 65 (66) (step S1). When the switching control valve 45 (46) is other than the neutral position, the outrigger jack 26 is being operated. When the switching control valve 45 (46) is in the neutral position, the outrigger jack 26 is not being operated. If the outrigger jack 26 has not been operated, the process ends.

  When the outrigger jack 26 is being operated, it is determined whether or not the load measured by the pressure sensor 81 exceeds a predetermined load threshold (step S2). If the load does not exceed the load threshold, the process returns to step S1. As described above, the load remains constant at 0 while the outrigger jack 26 starts to extend and contacts the ground (between A and B in FIG. 3). Since this step S2 excludes between the beginning of extension and the grounding, it is not erroneously determined that this interval is an overextended state. The load threshold is set to a positive value close to 0.

  When the load exceeds the load threshold value, it is determined whether or not the time change rate of the load measured by the pressure sensor 81 exceeds a predetermined change rate threshold value (step S3). Here, the pressure sensor 81 measures the load at regular time intervals, and the time change rate of the load is calculated, for example, by subtracting the previously measured load from the measured load. If the time change rate of the load exceeds the change rate threshold, the process returns to step S1. In this case, the outrigger jack 26 is between the time when the load gradually increases and the time when the front wheel starts to float (between B and C in FIG. 3).

  When the time change rate of the load is lower than the change rate threshold value, it is determined that the load does not change with time, and the outrigger jack 26 is determined to be in an excessively extended state (between C and D in FIG. 3). Note that the change rate threshold is set to a value that can determine whether or not the load is changing over time in consideration of the measurement error of the pressure sensor 81 and the like. In this case, a sound alarm is issued from the speaker 82 (step S4).

  As described above, the control means 70 can detect that the front wheel 14 of the loading-type truck crane 1 has floated by determining that the load applied to the outrigger jack 26 is no longer changed as an overextension state. And since an audio | voice warning is issued when the outrigger jack 26 is an overextension state, a worker can be urged to contract the outrigger jack 26. Therefore, the outrigger jack 26 can be contracted and set to an appropriate extended state.

  Note that when the outrigger jack 26 is driven at a low speed, the time change rate of the load is small even in the state of ground contact and the front wheel starts to float. Conceivable. Therefore, the change rate threshold value may be changed based on the driving speed of the outrigger jack 26. If the change rate threshold is increased when the driving speed of the outrigger jack 26 is slow, the above-described erroneous detection can be prevented. In this case, in place of the switching detection sensors 65 and 66, a position detection sensor capable of detecting the spool position of the switching control valves 45 and 46 is provided, so that the outrigger jack 26 is detected from the spool position of the switching control valves 45 and 46. The amount of hydraulic oil supplied to the vehicle can be calculated, and the drive speed of the outrigger jack 26 can be obtained.

  Moreover, you may judge an overextension state based on the change of the load with respect to the expansion-contraction length of the outrigger jack 26. FIG. In this way, it is possible to determine the overextension state without being influenced by the driving speed of the outrigger jack 26. In this case, the extension / contraction length of the outrigger jack 26 may be calculated from the amount of hydraulic oil supplied to the outrigger jack 26, or a length measuring unit that measures the extension / contraction length of the outrigger jack 26 may be provided. The measurement result may be input to the control means 70.

(Second Embodiment)
The outrigger jack extension state monitoring device according to the second embodiment of the present invention is the outrigger jack extension state monitoring device according to the first embodiment. The control means 70 determines that the outrigger jack 26 is in an overextension state. Sometimes, the outrigger jack 26 is contracted by a predetermined length.

More specifically, in step S4 (see FIG. 4), the pilot cylinder 55 (56) is driven by the control signal of the control means 70, the switching control valve 45 (46) is switched, and the outrigger jack 26 is set to a predetermined length. Shrink. The length to be contracted at this time is determined, for example, by calculating backward from the length of the outrigger jack 26 that extends from the proper extension state until the control means 70 determines that it is in the overextension state.
Since the rest of the configuration is the same as that of the first embodiment, description thereof is omitted.

  In the present embodiment, since the outrigger jack 26 is contracted for a predetermined length after the outrigger jack 26 is in an excessively extended state, the outrigger jack 26 can be set in an appropriate extended state without depending on the operation of the operator.

(Third embodiment)
The outrigger jack extension state monitoring device according to the third embodiment of the present invention is the same as the outrigger jack extension state monitoring device according to the first embodiment. Stop stretching.

  More specifically, as shown in FIG. 5 (a), the load applied when the outrigger jack 26 is in the proper extended state is determined in advance as a threshold value. When the outrigger jack 26 extends and the load measured by the pressure sensor 81 exceeds the threshold (time S in FIG. 5A), the pilot cylinder 55 (56) is driven by the control signal of the control means 70. Then, the switching control valve 45 (46) is switched to stop the extension of the outrigger jack 26.

  In the present embodiment, since the extension of the outrigger jack 26 is stopped when the load exceeds the threshold value, the outrigger jack 26 can be set in an appropriate extension state before the front wheel 14 of the loading truck crane 1 is lifted.

(Fourth embodiment)
The load applied when the outrigger jack 26 is in the proper extended state varies depending on the weight of the load-type truck crane 1 and the weight of the load. Therefore, in the outrigger jack extension state monitoring device according to the third embodiment, it is often difficult to uniquely determine the threshold value. Accordingly, the outrigger jack extension state monitoring device according to the fourth embodiment of the present invention determines the timing for stopping the extension of the outrigger jack 26 based on the time change rate of the load.

  More specifically, as shown in FIG. 5B, the control means 70 calculates the time change rate of the load from the load measured by the pressure sensor 81. As described above, the pressure sensor 81 measures the load at regular time intervals, and the time change rate of the load is calculated by, for example, subtracting the previously measured load from the measured load. The control means 70 sequentially updates the maximum value of the time change rate of the load from the beginning of expansion and contraction, and when the time change rate of the load decreases by a predetermined value from the maximum value (time S in FIG. 5B). Then, it is determined that the outrigger jack 26 is in the proper extended state. Then, the pilot cylinder 55 (56) is driven by the control signal of the control means 70, the switching control valve 45 (46) is switched, and the extension of the outrigger jack 26 is stopped. By doing so, the extension of the outrigger jack 26 can be stopped when the time change rate of the load exceeds the peak.

  In the present embodiment, since the extension of the outrigger jack 26 is stopped when the time change rate of the load exceeds the peak, the outrigger jack 26 is set to an appropriate extension state before the front wheel 14 of the loadable truck crane 1 is lifted. it can. Further, the extension of the outrigger jack 26 can be stopped at an appropriate timing regardless of the weight of the load-type truck crane 1 or the weight of the load.

  Instead of the time change rate of the load, the timing for stopping the extension of the outrigger jack 26 may be determined from the change rate based on the change in the load with respect to the expansion / contraction length of the outrigger jack 26.

(Fifth embodiment)
The outrigger jack extension state monitoring device according to the fifth embodiment of the present invention determines the timing to stop the extension of the outrigger jack 26 based on the time change rate of the load time change rate.

  More specifically, as shown in FIG. 5C, the control unit 70 calculates the time change rate of the load time change rate from the load measured by the pressure sensor 81. For example, the time change rate of the load is calculated by subtracting the load value measured last time from the load value measured by the pressure sensor 81, and then calculating the time change rate of the load. Calculated by subtracting the rate. The control means 70 determines that the outrigger jack 26 is in an appropriate extended state when the time change rate of the load time change rate becomes a negative value (time S in FIG. 5C). Then, the pilot cylinder 55 (56) is driven by the control signal of the control means 70, the switching control valve 45 (46) is switched, and the extension of the outrigger jack 26 is stopped.

  In this embodiment, since the extension of the outrigger jack 26 is stopped when the time change rate of the load time change rate becomes a negative value, the outrigger jack 26 is moved before the front wheel 14 of the loadable truck crane 1 is lifted. It can be set to an appropriate extension state. Further, the extension of the outrigger jack 26 can be stopped at an appropriate timing regardless of the weight of the load-type truck crane 1 or the weight of the load.

  Instead of the time change rate of the time change rate of the load, the timing for stopping the extension of the outrigger jack 26 is determined based on the change rate of the load with respect to the expansion / contraction length of the outrigger jack 26. Also good.

DESCRIPTION OF SYMBOLS 1 Loading type truck crane 26 Outrigger jack 26f Float 31 Hydraulic valve unit 70 Control means 81 Pressure sensor 82 Speaker

Claims (6)

Load measuring means for measuring the load applied to the outrigger jack;
Control means for inputting a measurement result of the load measuring means,
The extended state monitoring device for an outrigger jack, wherein the control means determines that the outrigger jack is in an over-extended state when the load measured by the load measuring means stops changing. Comprising alarm means connected to the control means;
2. The outrigger jack extension state monitoring device according to claim 1, wherein the control means activates the alarm means when it is determined that the outrigger jack is in an overextension state. The outrigger jack extension state monitoring device according to claim 1, wherein the control means contracts the outrigger jack by a predetermined length when it is determined that the outrigger jack is in an overextension state. Load measuring means for measuring the load applied to the outrigger jack;
Control means for inputting a measurement result of the load measuring means,
The outrigger jack extension state monitoring device, wherein the control means stops the extension of the outrigger jack when the load measured by the load measuring means exceeds a threshold value. Load measuring means for measuring the load applied to the outrigger jack;
Control means for inputting a measurement result of the load measuring means,
The outrigger jack extension state monitoring device, wherein the control means stops the extension of the outrigger jack when the rate of change of the load measured by the load measuring means exceeds a peak. Load measuring means for measuring the load applied to the outrigger jack;
Control means for inputting a measurement result of the load measuring means,
The outrigger jack extension state monitoring device characterized in that the control means stops the extension of the outrigger jack when the change rate of the load change rate measured by the load measuring means becomes a negative value. .

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