JP2007176650A - Turning range limiting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turning range limiting device capable of freely changing a turning setting range with a relatively inexpensive constitution. <P>SOLUTION: This turning range limiting device has a pair of proximity sensors 8A and 8B, a stopping position setting switch 10 outputting a turning range setting indicating signal for setting a stopping position, and a control part 20. The proximity sensors 8A and 8B are mutually respectively arranged for monitoring a position of dislocating a pitch in the tooth row direction of a gear 6 for driving a turntable 3. The control part 20 always counts one counting value corresponding to a present position of the turntable 3 in response to a difference in an output waveform of the pair of proximity sensors 8A and 8B, and also sets a desired turning setting range by associating the turning range setting indicating signal with the counting value at its time, and limits a turning range so as to turn the turntable 3 only in the turning setting range by always monitoring the counting value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a turning range limiting device for limiting a turning range of a revolving body in a work machine in which the revolving body performs a turning operation, and in particular, enables the revolving body to perform a turning operation only within a desired turning setting range. The present invention relates to a turning range limiting device capable of stopping a turning operation when a turning set range is exceeded.

In general, in a work machine such as a mobile crane having a turning body at the top, the turning direction of the turning body is switched by a lever operation by a driver, that is, a manual operation.
However, the turning range of the revolving structure may be restricted depending on the installation situation of the outrigger and the situation around the machine such as the presence of an obstacle. When the turning range is restricted in this way, the turning range of the turning body is limited to a predetermined turning setting range, and the turning body is automatically stopped before deviating from the predetermined turning setting range. It is desirable to limit

  Therefore, conventionally, as a device for limiting this kind of turning range, for example, a limit switch or the like is attached to the lower part of the turning body, and the turning body is automatically stopped by operating the limit switch during turning work, Alternatively, a member that limits a turning range mechanically by setting a predetermined turning setting range in advance by providing a member that limits the turning range is known (for example, see Patent Document 1).

In the technique described in Patent Literature 1, in a work machine including a non-revolving body and a revolving body that performs a revolving operation with respect to the non-revolving body, the relative movement between the non-revolving body and the revolving body is regulated. A restriction block is provided, and by this restriction block, the turning range of the revolving structure can be mechanically limited within a predetermined turning range.
Further, as another configuration, for example, a device such as an encoder or a potentiometer is built in a slip ring or the like, and a turning range is limited by detecting a turning direction and a turning angle by a controller. .
JP 2003-193511 A

  However, for example, when the turning body is automatically stopped by turning the limit switch during turning work, the limit switch and the detection body for operating the limit switch correspond to the turning setting range in advance. Must be installed in place. Therefore, once the turning setting range is set, it is not easy to reset the turning setting range by changing the mounting position of a limit switch or the like. This is the same even when, for example, the setting position of the restriction block is changed in the technique described in Patent Document 1.

On the other hand, for example, when the turning range is limited by the above-described slip ring or the like, the turning direction and the turning angle can be detected by the controller, for example. Equipment is generally expensive, and there is still room for improvement in view of the cost of installing the equipment.
Therefore, the present invention has been made paying attention to such problems, and an object thereof is to provide a turning range limiting device capable of easily changing the turning setting range with a relatively inexpensive configuration. .

  In order to solve the above-described problems, the present invention is used in a work machine in which a revolving body performs a revolving operation via a gear mechanism, and a revolving state detecting unit that detects a revolving state of the revolving body, and the revolving state detecting unit Based on the detection information detected by the current position specifying means for specifying the current position of the revolving structure, and the desired turning range of the revolving structure based on the current position information specified by the current position specifying means. A swivel range limiting device for limiting the swivel range within a swivel setting range, wherein the swivel state detecting means is installed so as to be able to detect the movement state of the gear mechanism in the dentition direction. A pair of non-contact type sensors are configured, and the pair of sensors makes the phases of the output waveforms different depending on whether the gear moves to one side or the other side in the dentition direction. Yo The current position specifying means adds a predetermined value to a count value for specifying the current position when moving toward the one side according to the phase difference, and When moving toward the side, a predetermined value is subtracted from the count value to obtain one count value corresponding to the current position as the current position information.

In addition, as an arrangement for making the phases of the output waveforms different when moving to one side in the dentition direction and when moving to the other side, for example, a pair of sensors are arranged in the dentition direction of the gear. By arranging each so as to monitor the position where the pitch is shifted, a desired signal can be output.
Here, the present invention can be suitably applied to a mobile crane as the work machine.

According to the present invention, the pair of sensors is installed at a position where the movement state of the gear mechanism in the dentition direction of the gear mechanism that causes the slewing body to perform the turning operation can be detected, and moves to one side in the dentition direction. Since the phases of the output waveforms are different between the case of moving to the other side and the case of moving to the other side, the turning direction of the revolving structure can be known from the relationship between the output waveforms of each other.
The current position specifying means adds a predetermined value to the count value for specifying the current position when heading to one side according to the phase difference, and when the head is heading to the other side, By subtracting a predetermined value from the count value, one count value corresponding to the current position is acquired as the current position information, so that the absolute position of the revolving structure can be known from the count value. . Therefore, for example, the moving state of the revolving structure can be detected with a relatively inexpensive configuration as compared with a device including the slip ring described above.

  And, for example, if the current position is positioned as one count value with respect to the desired turning setting range, the stop position is a position that has reached a value that is arbitrarily increased or decreased from one count value. Can be set to a desired turning setting range, for example, it is unnecessary to attach a device to a predetermined position corresponding to the turning setting range in advance as illustrated above, and the turning setting range can be easily changed. can do.

  Here, in order to easily change the turning setting range, it further includes a signal output means for outputting a turning range setting instruction signal for setting the turning setting range of the turning body, and the turning range restriction The means is configured to include a turning range setting means for setting the turning setting range, and the turning range setting means should restrict turning the current position information when the turning range setting instruction signal is output. The current position information acquired when the turning range setting instruction signal is output for the first time is used as one restriction position information, and the second time of the turning range setting instruction signal is stored. It is preferable to configure the turning setting range by storing the current position information acquired at the time of output as the other limited position information.

  With such a configuration, for example, when the turning body is set to a desired turning position by an operation of the driver of the work machine, the driver outputs a turning range setting instruction signal for setting the turning setting range. The turning range setting means can output a desired turning range by simply associating the count value at that time with the turning range setting instruction signal output by the signal output means. Can be set in the setting range. Therefore, for example, it is preferable in that it is unnecessary to attach the device to a predetermined position corresponding to the turning setting range in advance as exemplified above.

  Further, when the turning range setting instruction signal is output from the signal output means, the turning range setting means associates the current position information (count value) at that time as restricted position information for restricting turning. The operator of the work machine changes the turning setting range if the turning body is set to a desired turning position and the signal output means outputs a turning range setting instruction signal for setting the turning position again. Can also be easily done.

  In addition, the turning range restriction means turns the turning body so as to turn the turning body only when the count value as the current position information is between the count values as the one and the other restriction position information. It is more preferable if it is configured to limit the above. With such a configuration, the setting of the turning setting range and the limitation of the turning range based on the turning setting range can be managed only by the count value. Therefore, it is suitable for simplifying the configuration of the turning range limiting device.

  As described above, according to the present invention, it is possible to provide a turning range limiting device that can easily change the turning setting range with a relatively inexpensive configuration.

Hereinafter, an embodiment in which a turning range limiting device according to the present invention is mounted on a mobile crane will be described with reference to the drawings as appropriate.
FIG. 1 is a diagram for explaining the mobile crane. In FIG. 1, a schematic view seen from the plane direction is shown. Note that this mobile crane is the same as a known mobile crane except that a turning range limiting device according to the present invention described below is mounted, and therefore the description thereof will be omitted as appropriate.

  As shown in the figure, the mobile crane 1 includes a base 2 and a column 9 erected on the base 2 via a turntable 3 that is a revolving body that can be swiveled around a vertical axis. Is a working machine. A boom 4 that can extend and contract in the longitudinal direction is attached to an upper portion of the column 9. The boom 4 is configured to be able to be lifted and lowered with respect to the column 9, and a suspended load can be suspended with a rope at the tip portion thereof.

FIG. 2 is a diagram for explaining a gear mechanism and a hydraulic mechanism for driving the gear mechanism. In FIG. 2, the gear mechanism is shown in a schematic view when viewed from the plane, and a schematic configuration of the hydraulic mechanism is shown. It is also shown. FIG. 3 is a block diagram illustrating the configuration of the turning range limiting device according to the present invention.
As shown in FIG. 2, the mobile crane 1 has a gear mechanism 5 between the base 2 and the column 9 for turning the turntable 3. The gear mechanism 5 includes a large gear 7 that is coaxial with the turntable 3, and a small-diameter pinion gear 6 that meshes with the large gear 7. The pinion gear 6 is connected to the output shaft of the hydraulic motor 14. The hydraulic motor 14 is connected to the hydraulic pump 16 from the control valve 15 via the discharge pipe 17. As a result, the mobile crane 1 performs the switching operation of the control valve 15 to send the pressure oil from the hydraulic pump 16 to the hydraulic motor 14 and drive the gear mechanism 5 by the driving force to thereby turn the turntable 3. Can be turned in a desired rotation direction.

  An unload valve 18 is connected to the discharge line 17 of the hydraulic pump 16. The unload valve 18 is configured to be switchable between a position where the discharge pipe 17 is blocked and the hydraulic pump 16 is loaded, and a position where the hydraulic pump 16 communicates with the tank 19 and unloads. The unload valve 18 is controlled by inputting a control signal from the control unit 20, as shown in FIG.

  In addition, as shown in FIG. 2, a pair of proximity sensors 8 </ b> A and 8 </ b> B are disposed on the movable crane 1 substantially in parallel to the pinion gear 6 of the gear mechanism 5 on the radially outer side. . The proximity sensors 8A and 8B are turning state detecting means for detecting the turning state of the turntable 3 in a non-contact manner, and the proximity sensors 8A and 8B indicate the detected information at any time as shown in FIGS. As shown in FIG. 3, the control unit 20 is connected via a signal line so that output is possible.

  Further, as shown in FIGS. 2 and 3, the mobile crane 1 has a stop position setting switch 10 and a setting release switch 12, each of which receives a signal from the controller 20 by a switch operation by a driver, that is, a manual operation. Is connected to the control unit 20 through a signal line. The stop position setting switch 10 and the setting release switch 12 are provided on an operation panel (not shown) that can be operated by the driver. Here, the stop position setting switch 10 is a signal output means for outputting a turning range setting instruction signal for setting the turning setting range of the turntable 3, and outputs a signal only when the driver presses the switch. It is like that. The setting release switch 12 is a switch for switching from a state in which the turning range is restricted to a normal state in which the turning range is not restricted. When the switch is switched to either one, the signal on the switched side is continued. This is signal output means for outputting.

Next, the pair of proximity sensors 8A and 8B will be described in more detail.
Each of the proximity sensors 8A and 8B uses a sensor that can output the change caused by the proximity of the detection target as pulse detection information binarized to high “H” or low “L”, respectively, and is shown in FIG. As shown, when a tooth of the pinion gear 6 is detected, a detection signal “H” is output (reference numeral H in the figure), and when not, a detection signal “L” is output (in the figure, Symbol L). The pair of proximity sensors 8A and 8B can monitor positions where the tooth pitch in the tooth row direction of the pinion gear 6 for driving the turntable 3 is shifted by ¼ pitch. Has been placed. Accordingly, as shown in FIG. 4, the pair of proximity sensors 8A and 8B are different in the phase of the output waveform by the amount of shifting the pitch, and so to speak, generate two layers of pulses that are staggered. That is, the pair of proximity sensors 8A and 8B are configured such that the phases of the output waveforms differ depending on whether the pinion gear 6 moves to one side in the dentition direction or to the other side. . In the figure, the symbol P indicates a range corresponding to one pitch in the rotation direction of the pinion gear 6, and the symbol P / 4 indicates the pitch in the rotation direction of the pinion gear 6 as ¼ pitch. The shifted range is shown.

Next, the control unit 20 will be described in more detail.
This control unit 20 stores a CPU control program and the like in advance in a predetermined area and a CPU that controls the entire system of the mobile crane 1 based on a predetermined control program (not shown). The input / output of data to / from external devices including the ROM, the RAM read out from the ROM, the RAM for storing the calculation results required in the CPU calculation process, and the operation panel of the mobile crane 1 And an I / F (interface). These are connected to each other via a bus which is a signal line for transferring data so that data can be exchanged. From the operation panel, signals of the stop position setting switch 10 and the setting release switch 12 which are commands to execute the turning management process are input by a switch operation by the driver.

  Then, the control unit 20 acquires detection information of the pulse binarized to “H” or “L” detected by each of the proximity sensors 8A and 8B, and the acquired detection information is stored in the control unit 20 It can be stored in a predetermined area of the RAM. Further, the control unit 20 can identify the current position of the turntable 3 based on the detection information at any time detected by the proximity sensors 8A and 8B.

Here, the current position specifying process for specifying the current position of the turntable 3 in the control unit 20 will be described in detail. FIG. 5 is a flowchart of the current position specifying process executed in the control unit 20.
In the mobile crane 1, when the driver starts the operation of the mobile crane 1, the current position specifying process shown in the figure is executed by the CPU, and first, the process proceeds to step S <b> 21.

In step S21, it is determined whether or not the setting release switch 12 is ON. That is, if the setting release switch 12 is ON (YES), the process proceeds to step S22, and if not (NO), the process proceeds to step S23.
In step S22, the count value N for specifying the current position is reset to “0”, and the process proceeds to step S23. In step S23, the detection information detected by each proximity sensor 8A, 8B is acquired, and the process proceeds to step S24.

In step S24, a series of processes for specifying the turning direction (rotation direction) of the turntable 3 is performed, and the process proceeds to step S25.
Here, the pair of proximity sensors 8A and 8B are installed at positions where the phases of the output waveforms differ between when the pinion gear 6 moves to one side in the dentition direction and when it moves to the other side. However, in the series of processes in step S24, the turning direction (rotation direction) of the turntable 3 is specified according to the phase difference.

  In the following step S25, it is determined whether or not the turning direction (rotation direction) of the turntable 3 is the right turning direction. If the turning direction is the right turning direction (YES), the process proceeds to step S26; NO) Proceed to step S27. In step S26, 1 is added as a predetermined value to the count value N for specifying the current position, and the process returns to step S21. In step S27, 1 is subtracted as a predetermined value from the count value N for specifying the current position, and the process returns to step S21.

Here, the specification of the turning direction (rotation direction) of the turntable 3 will be described in detail.
As described above, the detection information of the proximity sensors 8A and 8B includes the signal change in the right turn direction (also called the count-up side) and the left turn direction (both the count-down side) as shown in FIG. This is different from the change in the signal. Therefore, the four patterns shown in the figure are stored as preset table data in the control unit 20, and combinations of the detection information of the proximity sensors 8A and 8B acquired at any time are expressed as follows. By comparing with each combination of table data, the turning direction can be specified. Here, the table data is stored in a predetermined area of the ROM in the control unit 20 so that it can be referred to as needed.

  More specifically, the detection information of the proximity sensor 8A acquired in step S23 changes from “H” to “L”, and the detection information of the proximity sensor 8B acquired at this time is “H”. If there is, the control unit 20 identifies that the turntable 3 is turning right in comparison with the combination of the table data (step S24). When the control unit 20 determines that the turntable 3 is turning right (YES in step S25), the cumulative number of pulses is set to N = N + 1 with respect to the count value N so far. A counting process for increasing (counting up) is performed, and a new count value N corresponding to the current position is newly acquired.

  Further, if the detection information of the proximity sensor 8A acquired in step S23 changes from “H” to “L” and the detection information of the proximity sensor 8B acquired at this time is “L”, the control is performed. The unit 20 specifies that the turntable 3 is turning left (step S24). When the control unit 20 determines that the turntable 3 is making a left turn (NO in step S25), the control unit 20 calculates the cumulative number of pulses with respect to the count value N so far as N = N−1. As a result, a counting process for subtracting (counting down) is performed, and a new count value N corresponding to the current position is newly acquired.

  Hereinafter, the same processing is performed for the four patterns shown in FIG. 6. As a result, the detection information acquired at any time increases or decreases the total number of pulses as appropriate according to the turning direction of the turntable 3 in the control unit 20. The counting process is performed to acquire one count value N corresponding to the current position of the turntable 3, and the rotation direction at the current position can be easily specified with reference to the table data. ing. Here, steps S21 to S27 in the current position specifying process correspond to the current position specifying means.

Next, the turning management process executed by the control unit 20 will be described in detail.
FIG. 7 is a flowchart of the turning management process executed in the control unit 20. FIG. 8 is a flowchart of the teaching process in step S3 of the turning management process.
In the turning management process in the mobile crane 1, when the driver starts the operation of the mobile crane 1, the turning management process shown in FIG. 7 is simultaneously executed in the CPU in parallel with the current position specifying process. First, the process proceeds to step S1.

In step S1, it is determined whether or not the setting release switch 12 is ON. That is, if the setting release switch 12 is ON (YES), the process proceeds to step S6, and if not (NO), the process proceeds to step S2.
In step S2, it is determined whether teaching (memory) for setting the turning setting range has been completed. This determination is made by referring to the teaching setting flag. If the teaching setting flag is “1”, that is, teaching is completed (YES), the process proceeds to step S4, and if the teaching setting flag is “0” (NO). The process proceeds to step S3. When the setting release switch 12 is turned “ON”, the teaching setting flag is set to “0” again.

  In step S3, a series of teaching processes are executed. That is, when this teaching process is executed, as shown in FIG. 8, first, the process proceeds to step S31 to determine whether or not the first stop position setting switch 10 has been pressed. That is, if the turning range setting instruction signal is output (YES), the process proceeds to step S32, and if not (NO), the process waits in step S31. In step S32, the count value N when the first stop position setting switch 10 is pressed is referred to and stored as a stop position (turn limit position) on one side. That is, the count value N is stored in a predetermined storage area as limited position information for limiting the turning on one side, and the process proceeds to step S33.

  Here, in the turning range limiting device of the present invention, one side and the other side in the turning direction of the turning body are not limited to the right turning direction and the left turning direction, but can be set from any side. In the description of the embodiment, in order to facilitate understanding, the description will be made assuming that one side is set to the right turning direction and the other side is set to the left turning direction. That is, in this example, the count value N in the right turn direction is stored as the limit position information in the predetermined storage area as the count value A of the stop position A, and the process proceeds to step S33. In the current position specifying process, the one side and the other side in the turning direction are not limited to the right turning direction and the left turning direction.

  In step S33, it is determined whether or not the second stop position setting switch 10 has been pressed. If pressed (YES), the process proceeds to step S34. If not (NO), the process waits in step S33. . In step S34, the count value N when the second stop position setting switch 10 is pressed is referred to, and the count value N is set to the stop position B (turn limit position) on the other side (in this example, the left turn direction). ) Is stored as limit position information in a predetermined storage area, the teaching setting flag is set to “1”, and the process is returned. That is, after completing the teaching process in step S3, the process returns to step S2.

In step S4, the count value N of the accumulated pulses counted in the current position specifying process is referred to as a count value N at the current position, and the process proceeds to step S5.
In step S5, it is determined whether or not the count value N at the current position is between the count value A and the count value B. That is, if the count value N is “count value A <count value N <count value B” (YES), the process proceeds to step S6; otherwise (NO), the process proceeds to step S7.

In step S6, a normal operation that is normally performed is executed and the process returns.
In step S7, the count value N and the count value B are compared. That is, if the count value N at the current position is “count value N ≦ count value B” (YES), the process proceeds to step S8; otherwise (NO), the process proceeds to step S9.
In step S8, predetermined left turn stop control is performed, and the process returns to step S2. That is, a control signal (a left turn stop signal) is output to the unload valve 18, and the unload valve 18 communicates the discharge line 17 of the hydraulic pump 16 with the tank 19 to unload the pressure oil. To do. Thereby, the turntable 3 stops turning to the left.

In step S9, the count value N and the count value A are compared. That is, if the count value N at the current position is “count value N ≧ count value A” (YES), the process proceeds to step S10; otherwise (NO), the process returns to step S2.
In step S10, predetermined right turn stop control is performed, and the process returns to step S2. That is, a control signal (right turn stop signal) is output to the unload valve 18, and the unload valve 18 communicates the discharge line 17 of the hydraulic pump 16 with the tank 19 to unload the pressure oil. Do. Thereby, the turntable 3 stops turning in the right direction.
Here, the turning range limiting means corresponds to the turning management process (steps S1 to S10) executed by the control unit 20, and the turning range setting means corresponds to step S3 (step S3) in the turning management process. S31 to S34) correspond.

Next, the operation and effect of this turning range limiting device will be described.
In this mobile crane, when limiting the turning range of the turntable 3 to a desired turning setting range, the driver first performs teaching for setting the desired turning setting range.
In the teaching, the driver turns the turntable 3 to the right until the boom 4 faces the one stop position A (see FIG. 1) where the turning is restricted.
Next, the driver presses the stop position setting switch 10 at the stop position A (first time). Thereby, the control part 20 matches this stop position A and the count value N which is the count number at that time, sets it as one turning restriction position, and memorize | stores this (steps S31-S32).

Next, the driver turns the turntable 3 to the left until the boom 4 faces the other stop position B (see FIG. 1) where the turning is restricted.
Next, the driver presses the stop position setting switch 10 at the stop position B (second time). Thereby, the control unit 20 associates the stop position B with the count value N that is the count number at that time, sets it as the other turning limit position, and stores this (steps S33 to S34).
As described above, the turning range desired by the driver is set as the turning setting range R. After the teaching, the driver can perform the turning operation only within the set turning setting range R by the turning management process executed by the control unit 20 even if driving without considering the turning range. It becomes possible (steps S4 to S10).

  Therefore, according to this turning range limiting device, even if the turning range of the turntable 3 including the boom 4 is restricted by the environment around the machine such as the installation condition of the outriggers and the presence of obstacles, for example. By limiting the turning range of the turntable 3 to the desired turning setting range R, the turntable 3 can be automatically stopped before it deviates from the desired turning setting range R. The driver can switch from the state where the turning range is limited to the normal state where the turning range is not limited at any time by pressing the setting release switch 12 (step S1).

  In particular, according to this turning range limiting device, the pair of proximity sensors 8A and 8B are installed at positions where the movement state of the gear 6 of the gear mechanism 5 that causes the turntable 3 to turn can be detected. Since the gears 6 are arranged so as to monitor the positions where the pitch of the gear 6 in the dentition direction is shifted by ¼ pitch, the proximity sensors 8A and 8B are connected to each other by the amount of the shifted pitch. A signal for making the phases of the signals different from each other is output (see FIG. 4). And the control part 20 can acquire one count value N according to the present position of the turntable 3 from the relationship of mutual output (refer FIG. 5). Therefore, according to the turning range limiting device, for example, the turning state of the turntable 3 can be detected and the absolute position can be specified by a relatively inexpensive configuration as compared with the device including the slip ring described above. .

  Furthermore, according to this turning range limiting device, when the operator of the mobile crane sets the boom 4 to a desired turning position, the turning position is set as a stop position by the stop position setting switch 10. The range setting instruction signal can be output to the control unit 20, and the control unit 20 simply associates the count value N at that time with the turning range setting instruction signal output from the stop position setting switch 10. Since the turning range can be set to the desired turning setting range R, for example, it is not necessary to attach a device to a predetermined position corresponding to the turning setting range in advance as exemplified above.

  Further, according to this turning range limiting device, the control unit 20 only associates the count value N at that time with the turning range setting instruction signal output from the stop position setting switch 10, so that the desired value can be obtained. When setting the turning setting range R, the driver resets the previous setting by the setting release switch 12 and again sets the turntable 3 to a desired turning position by the stop position setting switch 10. If the turning range setting instruction signal for setting the turning position as the stop position is output again, the turning setting range can be easily (freely) changed.

  Further, according to this turning range limiting device, the pair of proximity sensors 8A and 8B are installed at positions where the movement state of the gear 6 can be detected, and the stop position setting switch 10 and the setting release switch 12 are switched by the driver. Therefore, the control unit 20 may be configured to be able to execute the above-described turning management process (for example, a program), and can be retrofitted relatively easily even to a delivered vehicle.

As described above, according to this turning range limiting device, it is possible to provide a turning range limiting device that is relatively inexpensive and that can easily (freely) change the turning setting range.
The turning range limiting device according to the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, a mobile crane has been described as an example of a work machine on which the turning range limiting device according to the present invention is mounted. However, the present invention is not limited to this, and the present invention includes a revolving body at the top, If the revolving body is a work machine that performs a revolving operation via a gear mechanism, it can be applied to work machines such as various construction machines and cargo handling machines. However, mobile cranes are relatively often subject to restrictions on the turning range of the swivel body depending on the environment surrounding the machine, such as the outrigger installation status and the presence of obstacles. It is suitable as a work machine to be mounted.

  Moreover, in the said embodiment, although the example provided with the stop position setting switch 10 and the setting cancellation | release switch 12 was demonstrated as a signal output means, it is not limited to this, For example, only the stop position setting switch 10 is provided as a signal output means. It is good also as a structure. In this case, for example, when the stop position setting switch 10 is pressed for the third time, the control unit 20 can easily change the turning setting range by acquiring this as a reset signal. However, in the point of foolproof, such as preventing the erroneous operation in the operation of switching from the state in which the turning range is always restricted to the normal state in which the turning range is not restricted, the setting release switch 12 is separately provided as in the above embodiment. It is preferable to set it as the structure provided with.

Moreover, although the control part 20 demonstrated in the said embodiment the example which sets both the one side and the other side in a turning direction as the turning setting range R, it is not limited to this, Only one side is described. The stop position may be set, and the other side may be configured so that a normal turning operation is possible without restricting turning.
Further, in the above embodiment, the example has been described in which two stop positions associated with the count value N are set and the vehicle can turn only within one turning setting range R. However, the present invention is not limited to this. As another turning position associated with the numerical value N, a position at the center of the turning setting range may be further set, and it may be configured to temporarily stop at that position. For example, a range inside the turning setting range May be further set, and a turning position associated with the count value N may be further increased, such as a configuration in which an alarm is issued in advance at that position.

  In the teaching in the above embodiment, the control unit 20 pushes the stop position setting switch 10 at the stop position A (first time), thereby obtaining the stop position A and the count value N that is the count number at that time. Correspondingly, it is set as one turning limit position, then the boom 4 is turned to the other stop position B, the stop position setting switch 10 is pushed at the stop position B (second time), and this stop position B and at that time The count value N, which is the count number of each, is described as being set as the other turning limit position, but the control unit 20 pushes the stop position setting switch 10 at the stop position A (first time). , Once the count value N is initialized (for example, N = 0), the stop position A is set as a reference point, then the boom 4 is turned to the other stop position B, and the stop position B is set at the stop position B. Press switch 10 (second), it may be set the count value N counted from the stop position A is the stop position B and the reference point as the other of the pivot restricting position.

  In the above-described embodiment, the pair of proximity sensors 8A and 8B are installed at positions where the movement state of the pinion gear 6 of the gear mechanism 5 that causes the turntable 3 to perform a turning motion can be detected. Although the example in which the pitch in the rotation direction of 6 is arranged so as to monitor the position shifted by ¼ pitch has been described, the mutual position is not limited to the position shifted by ¼ pitch. The proximity sensors 8A and 8B monitor the positions shifted in pitch in the rotational direction within a range of more than 0 and less than ½ pitch, for example, so that the phases of the output waveforms are different from each other and become staggered. It only has to be arranged so as to generate a signal. However, in order to obtain a stable output, it is preferable that the positions of the pitches in the rotation direction of the pinion gear 6 are monitored so as to be shifted by a quarter pitch. Further, although the pinion gear 6 has been described as an example of the gear for detecting the moving state, a sensor may be attached to the large gear 7.

  Moreover, although the said embodiment demonstrated as an example provided with a pair of proximity sensor 8A, 8B as a turning state detection means which can detect the movement state in the dentition direction of a gearwheel, a pair of sensor is limited to a proximity sensor. For example, a photoelectric sensor may be used as long as it is a sensor that can detect the movement state of the gear in the dentition direction without contact. However, considering use in a bad environment such as water, oil, and dust, it is preferable to use a proximity sensor as a pair of sensors as in the above embodiment. Further, the direction of the detection shaft of the sensor with respect to the gear is not particularly limited as long as the movement state of the gear can be detected.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the mobile crane carrying the turning range limiting apparatus which concerns on this invention, In the same figure, the schematic seen from the plane direction is shown. It is a figure explaining the gear mechanism and the hydraulic mechanism for driving the gear mechanism. In the same figure, while showing the gear mechanism in the schematic seen from the plane direction, the schematic structure of the hydraulic mechanism is shown. It is a block diagram explaining the structure of the turning range limit apparatus which concerns on this invention. It is a timing chart explaining the output signal from a sensor. It is a flowchart of the absolute position setting process performed within a control part. It is a figure explaining the setting table referred when counting a count value within a control part based on the output signal from a sensor. It is a flowchart of the turning management process performed within a control part. It is a flowchart of the turning management process (teaching process) performed in a control part.

Explanation of symbols

1 Mobile crane (work machine)
2 Base 3 Turntable (swivel body)
4 Boom 5 Gear mechanism 6 Pinion gear 7 Large gear 8A, 8B Proximity sensor (turning state detection means)
9 Column 10 Stop position setting switch (Signal output means)
12 Setting Release Switch 14 Hydraulic Motor 15 Control Valve 16 Hydraulic Pump 17 Discharge Pipe 18 Unload Valve 19 Tank 20 Control Unit P Gear Pitch R Rotation Setting Range

Claims (3)

Based on detection information detected by a turning state detecting means for detecting a turning state of the turning body and a turning state detection means for detecting a turning state of the turning body, which is used in a work machine in which the turning body performs a turning operation via a gear mechanism. Current position specifying means for specifying the current position of the body, and turning range limiting means for limiting the turning range of the revolving body within a desired turning setting range based on the current position information specified by the current position specifying means A turning range limiting device comprising:
The turning state detecting means includes a pair of non-contact type sensors installed so as to be able to detect a movement state of the gear mechanism in the dentition direction of the gear mechanism, and the pair of sensors includes a pair of non-contact sensors. When moving to one side in the column direction and when moving to the other side, they are arranged to make the phases of the output waveforms different,
The current position specifying means adds a predetermined value to a count value for specifying the current position when heading toward the one side according to the phase difference, and when heading toward the other side, A turning range limiting device characterized in that one count value corresponding to a current position is acquired as the current position information by subtracting a predetermined value from the count value. In the turning range limiting device according to claim 1,
A signal output means for outputting a turning range setting instruction signal for setting a turning setting range of the revolving structure;
The turning range restriction means includes turning range setting means for setting the turning setting range, and the turning range setting means restricts turning of the current position information when the turning range setting instruction signal is output. Is stored as power limit position information,
The current position information acquired at the first output of the turning range setting instruction signal is used as one restriction position information, and the current position information acquired at the second output of the turning range setting instruction signal is set as the other restriction. The turning range limiting device characterized in that the turning setting range is arbitrarily set by storing it as position information. The turning range limiting device according to claim 2,
The turning range restriction means restricts the turning range so as to turn the turning body only when the count value as the current position information is between the count values as the one and the other restriction position information. A turning range limiting device.

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