JP2008247281A - Jack control device for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a jack control device capable of economically performing the horizontal installation of a working vehicle with sufficient workability. <P>SOLUTION: In the working vehicle in which a first jack 11 with a large stroke is arranged near a wheel 6 at a non-braking side and a second jack 12 with a small stroke is arranged near a wheel 7 at a braking side, the jack control device for the working vehicle is provided with a jack projection control means 17 for successively performing a first control step for performing the elongation of the first jack 11 and the time-measurement starting of a third timer 61, a second control step for starting the time measurement of a first timer 59 by the ground-contact of the first jack 11 and performing the elongation stopping of the first jack 11 and the elongation starting of the second jack with passing of a time, and a third control step for starting the time measurement of a second timer 60 by the ground-contact of the second jack 12 while retaining the first and second jacks 11, 12 to a horizontal state after a time is passed and elongating them. According to such a constitution, by the successive control of the first jack and the second jack using the first and second timers, horizontal installation work by the automatic operation of the working vehicle at the inclined ground can be safely and certainly performed in a state that the danger of deviation traveling and the unnecessary operation of the working vehicle are certainly eliminated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a work vehicle in which outriggers having jacks are arranged in the vicinity of front wheels and rear wheels, and more specifically, in a work vehicle in which the stroke of the jack near the front wheel is set longer than the stroke of the jack near the rear wheel. The present invention relates to a jack control device.

  In a work vehicle in which outriggers equipped with jacks are arranged in the vicinity of the front wheels and the rear wheels, technologies for extending and retracting jacks by automatic control have been proposed (see Patent Documents 1 to 3). .

  The thing shown in patent document 1 assumes the case where a work vehicle is horizontally installed on uneven ground, and installs the vehicle body of a work vehicle horizontally using jack cylinders arranged on the front, rear, left and right respectively. The first jack that is on one of the four jacks and is located on the side where the center of gravity of the vehicle body is located with respect to the other diagonal is extended until the grounding detector detects grounding. In addition, the second jack and the third jack on the other diagonal line are extended, and the vehicle body is horizontally supported by the first jack, the second jack, and the third jack. Thereafter, the fourth jack on the same diagonal as the first jack is extended until the grounding is detected by the grounding detector. In this case, the extension operation of the jack is performed by the operator based on the signal from the inclination detector and the signal from the ground detector.

  Patent Document 2 shows that when installing a work vehicle, all the jacks are temporarily extended to lift the tires of the work vehicle, and then the work vehicle is installed horizontally by reducing the jack with the higher flying height. A control device for a jack in the case where a grounding detector is disposed in each jack, and a tilt detector that detects the front, rear, left, and right tilts of the work vehicle is provided, and the work vehicle is substantially horizontal by the tilt detector. When the state is detected and the grounding state of each of the jacks is detected, it is determined that the horizontal installation is completed, thereby ensuring a safe horizontal installation in a state where all the jacks are grounded.

  In this case, the first timer that defines the total extension time of the jack that is extended in advance, the second timer that specifies the total extension time of the jack that is extended later, and the respective jacks are fully extended. Provided with a third timer for defining the horizontal adjustment time after the operation, and the first and second timers ensure the extension operation of each jack, and the third timer is installed horizontally even after the set time has elapsed. When the completion of this is not detected, it is determined that horizontal installation is impossible, thereby avoiding a wasteful overhanging operation in a state where horizontal installation is impossible.

  These Patent Documents 1 and 2 both assume a case where the installation ground of the work vehicle is relatively horizontal, and therefore there is no restriction on the operation order of each jack.

  On the other hand, what is shown in Patent Document 3 is based on the premise that the work vehicle is horizontally installed on an inclined land such as a slope with a relatively large inclination angle, and avoids danger such as escape of the work vehicle. Therefore, the present invention relates to a jack control apparatus for a work vehicle when there is a restriction on the operation order of each jack.

  That is, the work vehicle is equipped with a parking brake on either the front wheel side or the rear wheel side, and usually on the rear wheel side. Therefore, when a work vehicle is installed horizontally on a slope such as a slope, the work vehicle is stopped with its front wheels positioned at a low position and rear wheels positioned at a high position, and a parking brake is applied. Install the jack horizontally. In this case, if the rear wheel side floats from the ground earlier than the front wheel, the parking brake will not be effective, and the work vehicle may run away, and the safety in the work vehicle installation work will be impaired.

  Therefore, in the one described in Patent Document 3, when the work vehicle is installed horizontally, the jack on the front wheel side is first extended and the rear wheel is grounded (that is, the braking force by the parking brake is applied, Only the front wheels are lifted (while preventing escape). Thereafter, the rear wheel side jack is extended to float the rear wheel, and the extension amount of the front wheel side jack and the rear wheel side jack is adjusted to horizontally install the work vehicle. In this case, as in the case of Patent Document 2, the extension operation of each jack is controlled by a timer, thereby realizing a safe horizontal installation without danger such as escape of the work vehicle.

  On the other hand, in a work vehicle, it is common to set the stroke of the jack on the front wheel side and the stroke of the jack on the rear wheel side in the past, but when the work vehicle is installed horizontally on a sloping ground, the lower side in the tilt direction The jack located on the front wheel side (for example, the front wheel side) requires a large stroke, but the required stroke for the jack located on the higher side (for example, the rear wheel side) may be short. In the work vehicle that is the main usage pattern, from the beginning, the jack located on the lower side in the tilt direction is a large stroke jack, the jack located on the higher side is the small stroke jack, Attempts have been made to configure each (the so-called “front long jack specification”).

Japanese Utility Model Publication No. 6-23491 JP 2001-240387 A JP 2001-239924 A.

  By the way, when the operation of the jack is controlled by a timer, the setting time of the timer is conventionally set to a fixed time regardless of the inclination angle of the installation ground. The same applies to the work vehicle of "", and the setting time of the timer set based on the total extension time of the jack on the front wheel with a large stroke is similarly applied to the jack on the rear wheel with a small stroke.

  However, when the set time of the timer is fixedly set based on the total extension time of the jack on the front wheel with a large stroke in this way, for example, the inclination angle of the ground is more than the total extension of the jack on the front wheel side. If the tilt angle is such that the horizontal installation of the work vehicle is realized by extending to a small intermediate extension position, the horizontal installation has already been completed and no further jack extension operation is required. Regardless of this, the on-load state of the hydraulic system is maintained, the hydraulic pump continues to rotate at a high speed, etc., which is uneconomical in terms of fuel consumption, and there is a concern about environmental deterioration due to noise or exhaust gas. There was a problem that the performance decreased.

  Therefore, the present invention provides a work vehicle jack control device that is economical and has good workability by reflecting the ground inclination angle in the extension control of the jack when the work vehicle is horizontally installed. It was made as a purpose.

  In the present invention, the following configuration is adopted as a specific means for solving such a problem.

  In the first invention of the present application, either the front wheel or the rear wheel can be braked by the parking brake, and the first jack having a large jack stroke is provided near the wheel on the side not provided with the parking brake. An angle detector for detecting an inclination angle of the work vehicle in a work vehicle in which a second jack having a jack stroke smaller than that of the first jack is disposed in the vicinity of the wheel on the side provided with the first jack, and the first jack A first jack ground detector that detects that the second jack is grounded, a second jack ground detector that detects that the second jack is grounded, a first timer having a first set time, and a second setting. A first control step including a second timer having time, and extending the first jack in a state where the work vehicle is braked by the parking brake; A second signal for starting the timing of the first timer in response to a ground signal from the key detector and stopping the extension of the first jack and elongating the second jack after the elapse of the first set time. Control step, and receiving a grounding signal from the second jack grounding detector to start the time measurement of the second timer, and the first jack and the second jack until the second set time elapses. The present invention is characterized by comprising jack extension control means for sequentially executing a third control step of extending the work vehicle while keeping the level of the work vehicle.

  According to a second invention of the present application, in the work vehicle jack control device according to the first invention, a predetermined value is determined from a total set time of a first set time of the first timer and a second set time of the second timer. A third timer having a third set time which is larger by the time, and starting the time measurement of the third timer at the start of extension of the first jack in the first control step; In response to the elapse of the second set time, the extension of the first jack and the second jack is stopped, and the angle signal from the angle detector is received to reduce the higher-side jack. The fourth control process is characterized in that the vehicle is substantially leveled and the fourth control step is executed to stop the overhang control upon the passage of the third set time.

  In a third invention of the present application, in the work vehicle jack control apparatus according to the first or second invention, at least one of a first set time of the first timer and a second set time of the second timer. And a timer adjusting means for changing and adjusting one of the two in accordance with the inclination angle of the work vehicle in a state where the vehicle is stopped at the installation location.

  In the fourth invention of the present application, in the work vehicle jack control device according to the third invention, the second setting time of the second timer is set to be longer as the inclination angle is larger. It is a feature.

  In a fifth invention of the present application, in the work vehicle jack control device according to the first or second invention, when the angle signal of the angle detector is an angle signal corresponding to substantially horizontal, the angle signal is received. Jack length adjusting means for adjusting the maximum extension amount of the first jack so as to be equal to the maximum extension amount of the second jack is provided.

  In the present invention, the following effects can be obtained.

  (A) According to the jack control device for a work vehicle according to the first invention of the present application, the extension operation of the first jack is started in the first control step, and the first timer is started in the second control step. The amount of extension of the first jack after contact with the ground is regulated, and the wheel on the side not equipped with the parking brake is completely lifted and an accurate support state by the first jack is ensured. In the third control step, After the second jack is grounded by the second timer, the first jack and the second jack are simultaneously extended while being leveled, and the wheel provided with the parking brake is completely lifted.

  Therefore, according to the jack control apparatus for a work vehicle according to the present invention, the horizontal installation by the automatic operation of the work vehicle on an inclined ground by the sequential control of the first jack and the second jack using the first and second timers. The work is performed safely and accurately in a state in which dangers such as runaway of the work vehicle and unnecessary operations are surely excluded.

  In addition, since the horizontal installation of the work vehicle is completed at the time when the second timer expires, by switching the hydraulic system to the off-road state at this time, for example, the horizontal installation is already completed as in the conventional case. In spite of the fact that the jack extension operation is not necessary as described above, a situation in which the hydraulic system is kept on-load and the hydraulic pump keeps rotating at a high speed does not occur. In addition, the occurrence of the problem of environmental deterioration due to operating noise or exhaust gas can be prevented without fail.

  (B) In the work vehicle jack control apparatus according to the second invention of the present application, the first set time of the first timer and the second set time of the second timer are larger by a predetermined time than the total set time. A third timer having a set time of 3, and starts the time measurement of the third timer at the start of extension of the first jack in the first control step, while the jack extension control means includes the second timer When the set time elapses, the extension of the first jack and the second jack is stopped, and the angle signal from the angle detector is received to reduce the higher-side jack so that the work vehicle is substantially horizontal. And the fourth control step of stopping the overhang control upon the passage of the third set time is executed, so that the extension of the first and second jacks is performed with the passage of the second set time. Stopped In addition, the operation of reducing the jack on the higher side is performed based on the angle signal from the angle detector, so that the work vehicle is controlled to be more horizontal, and the set time of the third timer is elapsed. The jack extension operation is completed.

  Therefore, according to the jack control device for a work vehicle according to the present invention, the effect described in (a) can be further ensured by executing the fourth control step.

  (C) According to the jack control device for a work vehicle according to the third invention of the present application, in addition to the effects described in the above (a) or (b), the following specific effects can be obtained. That is, in the present invention, at least one of the first set time of the first timer, the second set time of the second timer, and the third set time of the third timer is stopped at the installation location. Since there is a timer adjustment means that changes and adjusts according to the inclination angle of the work vehicle in a state, generally, the larger the inclination angle of the work vehicle, the larger the jack stroke required to bring the work vehicle to a horizontal posture. Therefore, for example, the setting time of each timer can be optimized compared with the case where the setting time of each timer is fixedly set regardless of the magnitude of the inclination angle. Unnecessary extension operation of each jack and unnecessary on-load state of the hydraulic system after the horizontal installation of the work vehicle is prevented as much as possible. Low Improvement in reduction and workability can be expected.

  (D) According to the work vehicle jack control apparatus of the fourth invention of the present application, in addition to the effect described in (c) above, the following specific effects can be obtained. That is, according to the present invention, the second set time of the second timer is set to become longer as the tilt angle becomes larger. The second set time is set to the first jack and the second time. Since this is the time to extend the jack at the same time and is the part most affected by the magnitude of the tilt angle, this second set time is set to correspond to the tilt angle so that it becomes longer as the tilt angle is larger. By setting, unnecessary extension operation | movement of each jack is prevented as much as possible, and the improvement of workability | operativity is further accelerated | stimulated.

  (E) According to the work vehicle jack control apparatus of the fifth invention of the present application, in addition to the effects described in the above (a) or (b), the following specific effects can be obtained. That is, according to the present invention, when the angle signal of the angle detector is an angle signal corresponding to substantially horizontal (in other words, there is little need to change the inclination angle of the work vehicle, and most of the stroke of each jack is Jack angle adjustment for adjusting the maximum extension amount of the first jack to be equal to the maximum extension amount of the second jack in response to the angle signal. Because it is equipped with means, unnecessary extension of the first jack with a large jack stroke (that is, extension beyond the stroke necessary to lift the wheel) can be avoided, and the extension operation time of the jack can be shortened accordingly. As a result, improvement in workability in horizontal installation work of work vehicles can be expected.

  Hereinafter, the present invention will be specifically described based on preferred embodiments.

  1 to 3 show an aerial work vehicle Z as a work vehicle provided with a jack control device according to an embodiment of the present invention. This aerial work platform Z has a front wheel 6 and a rear wheel 7 mounted on a chassis frame 2 of a vehicle 1 equipped with a parking brake on the rear wheel 7 side. The telescopic boom 4 provided with a bucket 5 on its tip side is connected so as to be able to tilt up and down. Further, a pair of left and right front jacks 11 (corresponding to “first jacks” in the claims) and a pair of left and right rear jacks 12 (claims) are provided on the front, rear, left and right sides of the chassis frame 2. Corresponding to “second jack” in the range).

  Here, the aerial work vehicle Z according to this embodiment has a main usage pattern of “horizontal installation on an inclined road such as a slope”, and as shown in FIG. The front wheel 6 side without the parking brake is placed on the lower side, and the rear wheel 7 side with the parking brake is placed on the higher side with the forward leaning posture, and from this stopped state, the front jack 11 As shown in FIG. 3, the rear jack 12 is extended to support the vehicle 1 so as to float in a substantially horizontal state and perform a required work at a high place in this supported state.

  Therefore, as shown in FIG. 3, of the front jack 11 disposed in the vicinity of the front wheel 6 and positioned on the lower side, and the rear jack 12 positioned in the vicinity of the rear wheel 7 and positioned on the higher side. In the horizontal support state of the aerial work vehicle Z, the front jack 11 having a high support height is composed of a jack having a large jack stroke, and the rear jack 12 having a low support height is composed of a jack stroke having a small jack stroke. It is constituted by a jack and is a so-called “front long jack specification”.

  Note that, here, only the magnitude relationship between the rear jack 12 and the rear jack 12 is defined as “the rear jack 12 has a smaller jack stroke than the front jack 11”. When the aerial work vehicle Z is installed on a substantially flat ground, it is set to a sufficient jack stroke, that is, a “standard jack stroke” in a normal installation form, and the jack stroke of the rear jack 12 is set as a reference. The jack stroke of the front jack 11 is set longer.

  Further, in the case where such an aerial work vehicle Z is installed horizontally on an inclined ground, when the front work jack 11 and the rear jack 12 are extended so that the high work vehicle Z is in a jack support state, the operation work is in progress. In order to prevent the aerial work vehicle Z from running away, the operation order of the front jack 11 and the rear jack 12 is restricted.

  That is, first, only the front jack 11 is extended and the grounding state of the rear wheel 7 is maintained (that is, the braking force of the parking brake provided on the rear wheel 7 side is applied). 11 is grounded to the ground G through the planks 15, the front jack 11 is securely supported on the front side of the aerial work vehicle Z, and the front wheel 6 is lifted.

  Thereafter, the rear jack 12 is extended together with the front jack 11, and as shown in FIG. 3, the rear wheel 7 is levitated and the aerial work vehicle Z is levitated and supported in a substantially horizontal state. Such an operation procedure has already been described.

  By the way, in the “horizontal installation work” in which the above-mentioned high-altitude work vehicle Z is in a horizontal support state by extending the jacks 11 and 12 from the stopped state (that is, the fully contracted state of the front jack 11 and the rear jack 12). The operation control of the jacks 11 and 12 is automatically performed by the jack extension control means 17 described below.

  As shown in FIG. 4, the jack extension control means 17 receives the extension operation signal from the extension operation switch 16, and receives a right front jack extension solenoid 71, a left front jack extension solenoid 72, a right front jack reduction solenoid 73, and a left front. A control signal is appropriately output to each of the jack reduction solenoid 74, the right rear jack extension solenoid 75, the left rear jack extension solenoid 76, the right rear jack reduction solenoid 77, and the left rear jack reduction solenoid 78 to output the front jack 11 and the rear. The operation of the side jack 12 is controlled.

  On the other hand, the jack extension control means 17 receives a ground signal of the right front jack 11 from the right front jack ground detector 51 as a state signal serving as a state operation reference of the front jack 11 and the rear jack 12. The ground signal of the left front jack 11 from the jack ground detector 52, the ground signal of the right rear jack 12 from the right rear jack ground detector 53, and the left rear jack 12 of the left rear jack ground detector 54. Each ground signal is input. In addition, the jack extension control means 17 receives a full extension signal of the right front jack 11 from the right front jack full extension detector 55, and a full extension signal of the left front jack 11 from the left front jack full extension detector 56. However, the full extension signal of the right rear jack 12 is inputted from the right rear jack full extension detector 57, and the full extension signal of the left rear jack 12 is inputted from the left rear jack full extension detector 58. The full extension signal can be used when horizontal installation is performed by jack extension control instead of horizontal installation of the work vehicle by timer control as will be described later.

  The jack extension control means 17 receives an adjustment timer signal from the timer adjustment means 18 and a length adjustment signal from the jack length adjustment means 19 described below.

  The timer adjusting means 18 adjusts a timer signal that is a temporal operation reference of the front jack 11 and the rear jack 12 according to the inclination angle of the aerial work vehicle Z, and outputs this as the adjustment timer signal. Therefore, as the timer signal, the “first set time” from the first timer 59, the “second set time” from the second timer 60, and the total timer 61 (“ “Corresponding to“ third timer ”) is input with“ third set time ”.

  Further, the angle signal output corresponding to the inclination angle of the aerial work vehicle Z detected by the angle detector 62 provided on the vehicle body side is the jack extension control means 17, the timer adjustment means 18, and the jack length. Each is input to the height adjusting means 19. In this embodiment, the angle detector 62 provided on the vehicle body side is used to detect the inclination angle of the aerial work vehicle Z. However, in other embodiments, instead of this, for example, the boom The angle detector for boom undulation angle detection provided as standard on the 4 side can also be used for detecting the tilt angle of the aerial work vehicle Z, and according to such a configuration, cost reduction by reducing the number of parts is expected. it can.

  When the angle signal from the angle detector 62 is an angle signal corresponding to a substantially horizontal angle, the jack length adjusting means 19 receives the angle signal and determines the maximum extension amount of the front jack 11 to the rear jack. It adjusts so that it may become equal to the maximum expansion amount of 12, and avoids an unnecessary expansion | extension operation | movement.

  As a specific configuration of the jack length adjusting means 19, for example, the extension length of the front jack 11 is regulated by the extension operation time, or the extension length is directly detected and regulated, or a stopper member. Therefore, a configuration is conceivable in which the extension movement of the front jack 11 is forcibly restricted at a predetermined position. There is also a method in which the operator manually determines the extension length of the front jack 11 (that is, visually recognizes that the front jack 11 has reached a predetermined extension length and stops the extension operation at that time). Conceivable.

  Here, prior to concrete description of actual control based on the control flowchart shown in FIG. 5, the set times of the timers 59, 60, 61 and the ground G on which the aerial work vehicle Z is installed are set. The angle correlation will be described. Here, the ground angle is adopted as the “ground angle” with the vehicle body inclination angle detected by the angle detector 62 installed in the aerial work vehicle Z.

  The first timer 59 extends from the time when the pair of left and right front jacks 11 to be extended in advance reaches the ground, and further extends the front jack 11 to ensure the support state by the front jack 11. ("First set time" in the claims).

  The second timer 60 extends when the pair of left and right rear jacks 12 that are extended in the rearward direction are grounded and the front jack 11 is simultaneously extended with the rear jack 12 while being leveled. Time ("second set time" in the claims) is defined.

  The total timer 61 (“third timer 61” in the claims) completes the final horizontal adjustment from the start of the extension operation of the front jack 11 that is extended in advance, and the aerial work vehicle Z is moved horizontally. The total time until the installation state is set (“third set time” in the claims) is defined.

  The set times of the timers 59, 60, 61 are set in accordance with the angle of the ground G on which the aerial work vehicle Z is installed. That is, in this embodiment, as shown in FIG. 6, the ground angle as a control reference (angle “α” in FIGS. 1 to 3) is set to a range of “−5 ° to + 5 °” and “−5 ° to It is divided into the range of “−11.3 °”.

  In this embodiment, the range of the ground angle “−5 ° to + 5 °” is handled as a range that can be regarded as “the ground is horizontal”. This handling is the same in the horizontal adjustment control of the aerial work vehicle Z described later, as well as the setting criteria for the setting time of each timer.

  Further, the ground angle range of “−5 ° to −11.3 °” is inclined, and is handled as “a range that should be considered for prevention of escape” when the aerial work vehicle Z is installed horizontally.

  From this point of view, in this embodiment, as shown in FIG. 6, the correlation between the “ground angle”, the “timer setting time”, and the “jack stroke” adjusted by the jack length adjusting means 19 is set.

  That is, first, the ground angle is divided into a range of “−5 ° to + 5 °” treated as horizontal and a range of “−5 ° to −11.3 °” treated as an inclined surface.

And for “timer setting time”,
In the range of the ground angle “−5 ° to −11.3 °”, the setting time of the first timer 59 is “2 seconds”, the setting time of the second timer 60 is “10 seconds”, and the setting time of the total timer 61 is “35 seconds”
In the range of the ground angle “−5 ° to −11.3 °”, the setting time of the first timer 59 is “2 seconds”, the setting time of the second timer 60 is “18 seconds”, and the setting time of the total timer 61 is “45 seconds”.

About "jack stroke"
In the range of the ground angle “−5 ° to −11.3 °”, the front jack 11 has an intermediate stroke of “605 mm” and the rear jack 12 has a full extension stroke of “605 mm”.
In the range of the ground angle “−5 ° to −11.3 °”, the front jack 11 has a full extension stroke of “870 mm”, and the rear jack 12 has a full extension stroke of “605 mm”. That is, in the range of the ground angle “−5 ° to −11.3 °”, the stroke of the front jack 11 is matched with the full extension stroke of the rear jack 12 to avoid unnecessary extension of the front jack 11. Therefore, the work time for horizontal installation is shortened.

  Next, the jack extension control in the case where the aerial work vehicle Z is horizontally installed on the inclined ground G will be specifically described based on the control flowchart shown in FIG.

  The jack extension control is started from a state where the aerial work vehicle Z is stopped in a forward leaning posture on the inclined ground G and a parking brake is applied to the rear wheel 7 side. Therefore, before the start of this control, both the front jack 11 and the rear jack 12 are fully contracted, and the aerial work vehicle Z is supported on the ground G by the front wheels 6 and the rear wheels 7.

  In this state, when the overhang operation switch 16 is operated, jack overhang control for horizontally installing the aerial work platform Z is started (step S1). After the control is started, the flag F is first reset to “F = 0” (step S2), and the vehicle body angle (that is, the ground angle “α”) is read (step S3).

  Next, in step S4, it is determined whether the aerial work vehicle Z is currently in a horizontal state (that is, whether the ground angle “α” is in the range of “−5 ° to + 5 °”).

  If it is determined that the current state is horizontal, the jack length adjusting means 19 adjusts the extension amount of the left and right front jacks 11 (step S5). That is, in this case, the stroke of the front jack 11 is adjusted to “605 mm” which is the same as the full extension stroke of the rear jack 12, and the front jack 11 has a stroke “605 mm” smaller than the full extension stroke “870 mm”. However, it is not extended beyond “605 mm”.

  If it is determined in step S4 that the current position is not horizontal, the process immediately proceeds to step S6 after the stroke adjustment in step S5 described above.

  In step S6, the set times of the timers 59 to 61 are adjusted in accordance with the ground angle “α”. That is, as shown in FIG. 6, when the ground angle “α” is in the range of “−5 ° to + 5 °”, the set time of the first timer 59 is set to “2 seconds”, and the set time of the second timer 60 is set. “10 seconds” and the set time of the total timer 61 are set to “35 seconds”, respectively. On the other hand, when the ground angle “α” is in the range of “−5 ° to −11.3 °”, the set time of the first timer 59 is “2 seconds” and the set time of the second timer 60 is “18 seconds”. Further, the set time of the total timer 61 is set to “45 seconds”.

  Here, the setting time of the first timer 59 is set to the same length as “2 seconds” regardless of the ground angle “α”. The setting time of the first timer 59 is the grounding of the front jack 11. This is because the front jack 11 is further extended later to ensure its support state, and there are almost no elements governed by the magnitude of the ground angle.

  On the other hand, the second timer 60 extends the front jack 11 and the rear jack 12 at the same time, and lifts the work vehicle Z at a height to near the horizontal installation height. As the ground angle “α” is larger, the required extension amount of the front jack 11 and the rear jack 12 becomes longer, so that the ground angle “α” is in the range of “−5 ° to + 5 °”. In some cases, it is set to “10 seconds”, and when the ground angle “α” is in the range of “−5 ° to −11.3 °”, it is set to “18 seconds”.

  The total timer 61 defines the total time from the start of the extension operation of the front jack 11 that is extended in advance until the final horizontal adjustment is completed and the aerial work vehicle Z is set in the horizontal installation state. As in the second timer 60, there are many factors governed by the magnitude of the ground angle. Therefore, the ground angle “α” is set to “−5” substantially corresponding to the setting of the second timer 60. When it is in the range of “° to + 5 °”, it is set to “35 seconds”, and when the ground angle “α” is in the range of “−5 ° to −11.3 °”, it is set to “45 seconds”.

  Here, the set times of the timers 59 to 61 are changed in accordance with the ground angle “α”. However, other than this, for example, conditions of the driving source (for example, the PTO shaft of the engine of the own vehicle) It is also possible to change the rotation speed depending on whether the rotational speed is high or low, when the battery is taken out from another engine other than the own vehicle engine, or when a battery is used.

  Returning to FIG. 5, after adjusting the timer in step S6, actual jack control is started. First, the total timer 61 starts counting (step S7), and the left and right front jacks 11 are extended. (Step S8 and Step S9). Then, when each of the front jacks 11 is grounded (that is, when a ground signal is input from the right front jack ground detector 51 and the left front jack ground detector 52), flag determination is performed (step S12).

  Initially, since the flag is “F = 0”, the timing of the first timer 59 is started in step S13, the flag is set to “F = 1” in step S14, and the first timer 59 is set in step S15. Determine time-up. Until the first timer 59 expires, the extension operation of the left and right front jacks 11 is continued (steps S8 to S12), and the extension of the left and right front jacks 11 is stopped after the time is up (steps S16 and S12). Step S17).

  FIG. 2 shows the state of the aerial work vehicle Z at this time. In this state, the left and right front jacks 11 are grounded and further extended by a predetermined amount, so that the front side of the aerial work vehicle Z is reliably supported by the front jacks 11 and the front wheels 6 are lifted. However, the rear wheel 7 is still in contact with the ground and the braking force by the parking brake is working. Therefore, this braking action reliably prevents the aerial work vehicle Z from running away.

  Subsequently, the operation proceeds to the floating operation on the rear wheel 7 side. That is, in steps S18 and S19, the left and right rear jacks 12 are started to be extended. Then, when the rear jacks 12 are grounded together (that is, when a ground signal is input from the right rear jack ground detector 53 and the left rear jack ground detector 54), the time counting of the second timer 60 is performed. Is started (step S22).

  Thereafter, while performing horizontal adjustment (step S23), the left and right front jacks 11 are extended in parallel with the extension operation of the rear jacks 12 (step S24 and step S25). 11 and 12, the aerial work vehicle Z is levitated while maintaining a posture close to horizontal. Here, the horizontal adjustment in step S23 is based on the angle signal continuously input from the angle detector 62, for example, by extending the jack located on the higher side in the inclination direction of the jacks 11 and 12. This is performed by temporarily stopping and waiting for the extension of the jack located on the lower side.

  When the second timer 60 expires (step S26), the extension of the jacks 11 and 12 is stopped (step S27). Further, until the total timer 61 expires (step S29), final horizontal adjustment, that is, adjustment work for adjusting the height by reducing the jack on the higher side is performed (step S28). The jack extension control is terminated when the total timer 61 is up.

  FIG. 3 shows the state of the aerial work vehicle Z at the end of the jack extension control. In this state, the aerial work vehicle Z is levitated and supported in a horizontal state by the left and right front jacks 11 and the left and right rear jacks 12, and can operate at a high place by operating the telescopic boom 4. ing.

  In addition, although it is a response | compatibility with the said 1st control process-the 4th control process of the said jack extension control means 17, and the said control flowchart, in this embodiment, a 1st control process is step S1-step S11. Correspondingly, the second control process corresponds to steps S12 to S21, the third control process corresponds to steps S22 to S26, and the fourth control process corresponds to steps S27 to S29.

  As described above, the aerial work platform Z provided with the jack control device according to this embodiment includes the jack extension control means 17, and the jack extension control means 17 includes the first control step to the first control step. 4 in the first control step, the extension of the front jack 11 is started and the time counting of the total timer 61 for defining the total time of the overhang operation is started. 1 timer 59 defines the amount of extension of the front jack 11 after grounding, and the front wheel 6 on the side not provided with the parking brake is completely lifted and an accurate support state by the front jack 11 is ensured. In the control step, the simultaneous extension time of the front jack 11 and the rear jack 12 after the rear jack 12 is grounded by the second timer 60 is regulated. The rear wheel 7 having the parking brake is completely lifted, and in the fourth control step, the extension of the front jack 11 and the rear jack 12 is stopped and the height of the second timer 60 is increased. Since the work vehicle is controlled in a substantially horizontal posture by performing the reduction operation of the high-side jack, and the jack extension operation is completed by the time-up of the total timer 61, the above-described operation using each timer is performed. Sequential control of the front jack 11 and the rear jack 12 ensures that the horizontal installation work by the automatic operation of the aerial work platform Z on an inclined ground ensures the danger such as escape of the aerial work platform Z and unnecessary operation. A jack system that can be safely and accurately performed in the state of being removed, and by extension, can be used for horizontal installation of the work vehicle Z at high height economically and with good workability. It is possible to provide a device.

  In addition, since the horizontal installation of the work vehicle is completed by the time-up of the total timer 61, by switching the hydraulic system to an off-road state at this time, for example, the horizontal installation has already been completed as in the conventional case. In spite of the fact that the extension operation of the jack is not necessary, the on-load state of the hydraulic system is maintained and the hydraulic pump keeps rotating at a high speed. At the same time, the problem of environmental deterioration due to operating noise or exhaust gas can be prevented without fail.

  Also, according to the jack control device of this embodiment, the set time of the second timer 60 among the set time of the first timer 59, the set time of the second timer 60, and the set time of the total timer 61, Since there is provided timer adjustment means 18 for changing and adjusting the set time of the total timer 61 in accordance with the inclination angle of the aerial work vehicle Z (that is, the angle of the installation ground G) when the vehicle is stopped, generally the work at a high place is performed. The greater the inclination angle of the vehicle Z, the greater the jack stroke required to place the aerial work vehicle Z in a horizontal position. For example, the timers 59 to 61 of the timers 59 to 61 are independent of the inclination angle. Compared with the case where the set time is fixedly set, the set times of the timers 59 to 61 can be optimized, and as a result, the jacks 11 and 12 are unnecessarily expanded. After the installation and horizontal installation of the aerial work platform Z is completed, unnecessary on-load state of the hydraulic system is prevented as much as possible. And improvement in workability can be expected.

It is a side view in the stop state of an aerial work vehicle according to an embodiment of the present invention. It is a side view which shows the state which extended only the front side jack from the state shown in FIG. It is a side view which shows the state which also extended the rear side jack from the state shown in FIG. It is a control block diagram of a jack. It is a control flowchart of a jack. It is a correlation diagram of the jack stroke with respect to the ground angle and the timer setting time.

Explanation of symbols

1 ·· Vehicle 2 ·· Chassis frame 3 · · Turntable 4 · · Telescopic boom 5 · · Bucket 6 · · Front wheel 7 · · Rear wheel 11 · · Front jack (first jack)
12 ..Rear jack (second jack)
13 ..Float 14 ..Float 15 ..Steel 16 ..Extension control switch 17 ..Jack extension control means 18 ..Timer adjustment means 19 ..Jack length adjustment means 51 ..Right front jack grounding detector 52 ..Left front jack ground detector 53 ..Right rear jack ground detector 54 ..Left rear jack ground detector 55 ..Right front jack full extension detector 56 ..Left front jack full extension detector 57. Total extension detector 58 ・ ・ Left rear jack total extension detector 59 ・ ・ First timer 60 ・ ・ Second timer 61 ・ ・ Third timer (total timer)
62 ·· Angle detector 71 ·· Right front jack extension solenoid 72 ·· Left front jack extension solenoid 73 ·· Right front jack reduction solenoid 74 ·· Left front jack reduction solenoid 75 ·· Right rear jack extension solenoid 76 ·· Left rear jack extension solenoid G ・ ・ Ground Z ・ ・ Aerial work vehicle

Claims (5)

The front brake and the rear wheel can be braked by the parking brake, the first jack having a large jack stroke is provided in the vicinity of the wheel on the side not provided with the parking brake, and the wheel on the side provided with the parking brake is provided. In the work vehicle in which the second jack having a smaller jack stroke than the first jack is disposed,
An angle detector for detecting a tilt angle of the work vehicle, a first jack ground detector for detecting that the first jack is grounded, and a second jack ground detector for detecting that the second jack is grounded; A first timer having a first set time and a second timer having a second set time,
A first control step of extending the first jack while the work vehicle is braked by the parking brake; and a grounding signal from the first jack grounding detector is received to start timing of the first timer. In response to the elapse of the first set time, the second control step of stopping the extension of the first jack and extending the second jack, and receiving the ground signal from the second jack ground detector, the second A jack extension that sequentially executes a third control step of starting the timing of two timers and extending the first jack and the second jack together while leveling the work vehicle until the second set time elapses. A work vehicle jack control device characterized by comprising an exit control means. In claim 1,
A third timer having a third set time that is larger by a predetermined time than a total set time of the first set time of the first timer and the second set time of the second timer, in the first control step While starting the third timer at the time when the first jack starts to extend,
The jack extension control means stops the extension of the first jack and the second jack after the elapse of the second set time, and receives the angle signal from the angle detector and increases the height. The work vehicle jack control device is characterized in that a fourth control step is executed to reduce the jack of the vehicle to make the work vehicle substantially horizontal and to stop the overhang control after the elapse of the third set time. . In claim 1 or 2,
A timer that changes and adjusts at least one of the first set time of the first timer and the second set time of the second timer in accordance with the inclination angle of the work vehicle when stopped at the installation location. A work vehicle jack control device comprising an adjusting means. In claim 3,
2. A jack control apparatus for a work vehicle, wherein the second set time of the second timer is set to become longer as the tilt angle becomes larger. In claim 1 or 2,
When the angle signal of the angle detector is an angle signal corresponding to substantially horizontal, the angle signal is received and the maximum extension amount of the first jack is adjusted to be equal to the maximum extension amount of the second jack. A jack control device for a work vehicle, comprising a jack length adjusting means.

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