JP2018200005A - Control device for work machine - Google Patents

Abstract

To provide a control technology capable of appropriately determining initial abnormality of a fan belt while adopting a rational configuration in a work machine for actuating an actuation section by transmitting engine power to the actuation section with a hydraulic pressure or the like along with operation of an operation section.SOLUTION: A control device for a work machine includes automatic deceleration control means 31 for executing deceleration control for maintaining a speed of an engine 10 at a predetermined low speed when an operation section A is not operated and executing speed return control for returning the speed of the engine 10 from the low speed to a predetermined rated speed larger than the low speed when the operation section A is operated. The control device further includes: first slip detection means 32 for detecting occurrence of slip of a fan belt 15 in a speed increase period during execution of the speed return control by the automatic deceleration control means 31; and belt state determination means 35 for determining a state of the fan belt on the basis of a detection result obtained by the slip detection means 32.SELECTED DRAWING: Figure 2

Description

  The present invention provides a working machine including an engine that generates power, an operating unit that operates by power of the engine, and an operation unit that performs transmission operation of the power of the engine to the operating unit. Of a work machine including slip detection means for detecting occurrence of slip of a fan belt that transmits a fan to a cooling fan, and belt state determination means for determining a state of the fan belt based on a detection result of the slip detection means The present invention relates to a control device.

  As a conventional technique for automatically determining abnormalities such as wear, looseness, cracks, cracks, etc. in the fan belt in the engine, the measurement result of the rotation speed of the engine and the measurement result of the rotation speed of the cooling fan are used. Comparing and detecting the occurrence of slip of the fan belt depending on whether or not a difference of more than a predetermined value occurs between them, and outputting an alarm that the fan belt is abnormal when it is detected that the slip has occurred Is known (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 58-98437

In a working machine such as an agricultural machine such as a combine machine or a construction machine such as a backhoe that transmits the engine power to the operating part by hydraulic pressure or the like in accordance with the operation of the operating part, the operating part is usually operated. During the operation to be operated, the rotation speed of the engine is maintained at a constant rotation speed such as a rated rotation speed. In such a working machine, even when a small initial abnormality occurs in the fan belt of the engine, the occurrence of slip is suppressed because the speed fluctuation of the fan belt is small.
Therefore, in such a working machine, the state of the fan belt is determined depending on the occurrence of slippage of the fan belt in the state where the conventional technology described in Patent Document 1 is adopted and the rotational speed of the engine is maintained at a constant rotational speed. However, there is a problem that the initial abnormality of the fan belt cannot be determined.

  In view of this situation, the main problem of the present invention is to adopt a rational configuration in a work machine that operates the operation unit by transmitting engine power to the operation unit by hydraulic pressure or the like in accordance with operation of the operation unit. It is in providing a control technique that can appropriately determine an initial abnormality of a fan belt.

A first characteristic configuration of the present invention is a work machine including an engine that generates power, an operation unit that operates by power of the engine, and an operation unit that performs transmission operation of the power of the engine to the operation unit. ,
Slip detecting means for detecting occurrence of slip of the fan belt for transmitting the power of the engine to a cooling fan;
A control device for a work machine, comprising: a belt state determination unit that determines a state of the fan belt based on a detection result of the slip detection unit;
When the operation unit is not operated, a deceleration control is performed to maintain the engine rotation speed at a predetermined low rotation speed, and the engine rotation speed is increased from the low rotation speed to a predetermined value higher than the operation speed when the operation unit is operated. Equipped with auto-decel control means to increase the rated rotational speed of
As the slip detection means, there is provided first slip detection means for detecting occurrence of slip of the fan belt during a rotation speed increase period while the rotation speed of the engine is increased to the rated rotation speed by the auto-decel control means. It is in the point.

According to this configuration, since the auto-decel control means is provided, when the operation unit that does not operate the operation unit is not operated, the decel control is executed to maintain the engine rotation speed at a low rotation speed, so that the engine noise and fuel consumption are reduced. Can be reduced. Further, when operating the operating unit that operates the operating unit, the rotational speed of the engine can be returned to the rated rotational speed, and the power of the engine can be appropriately transmitted to the operating unit.
Since the first slip detection means is provided as the slip detection means for detecting the occurrence of the fan belt slip, the belt state determination means can appropriately determine the initial abnormality of the fan belt. In other words, the engine speed rapidly increases from the low speed to the rated speed during the above speed increase period, so even if there is only a relatively small initial abnormality in the fan belt, It will be in the state where slip of this occurs easily. Therefore, when it is detected by the first slip detection means that the fan belt slips within the rotation speed increase period, the belt state determination means determines that the fan belt has at least an initial abnormality. For example, maintenance such as adjustment or replacement of the fan belt can be performed early using the determination result.
Therefore, according to the present invention, in the working machine that transmits the engine power to the operating part by hydraulic pressure or the like in accordance with the operation of the operating part and operates the operating part, the initial abnormality of the fan belt can be prevented while adopting a rational configuration. It is possible to provide a control device for a work machine that can be appropriately determined.

The second characteristic configuration of the present invention comprises fan rotation speed measuring means for measuring the rotation speed of the cooling fan,
The first slip detection means acquires the cooling fan rotation speed at a predetermined timing within the rotation speed increase period as the rising fan rotation speed by the fan rotation speed measurement means, and the rising fan rotation speed is It is a means for detecting that the fan belt has slipped when the rotational speed is lower than a predetermined set fan rotational speed.

  According to this configuration, it is not necessary to use the measurement result of the engine rotation speed, and only the measurement result of the fan rotation speed measurement means is used, and the slip of the fan belt within the rotation speed increase period is detected by the first slip detection means. Can be detected. That is, the engine speed is automatically increased by the auto-decel control means within the rotation speed increase period, so that the engine rotation speed at a predetermined timing within the rotation speed increase period is known in advance. Become. Therefore, if the set fan rotation speed is set based on the known engine rotation speed at that timing, and the cooling fan rotation speed at that timing is measured as the rising fan rotation speed, the measured rising fan rotation speed When the speed is less than the set fan rotation speed, it can be detected that a fan belt slip has occurred.

The third characteristic configuration of the present invention comprises fan rotation speed measuring means for measuring the rotation speed of the cooling fan,
The first slip detection means acquires, as the fan rotation speed increase rate, an increase rate of the cooling fan rotation speed within the rotation speed increase period by the fan rotation speed measurement means, and the fan rotation speed increase rate is predetermined. This is a means for detecting that the fan belt has slipped when the fan rotational speed increase rate is less than the set rate.

  According to this configuration, it is not necessary to use the measurement result of the engine rotation speed, and only the measurement result of the fan rotation speed measurement means is used, and the slip of the fan belt within the rotation speed increase period is detected by the first slip detection means. Can be detected. That is, since the engine speed is automatically increased by the auto-decel control means during the rotation speed increase period, the increase rate of the engine rotation speed during the rotation speed increase period is known in advance. . Therefore, if the above set fan rotation speed increase rate is set based on the known engine rotation speed increase rate and the cooling fan rotation speed increase rate is measured as the fan rotation speed increase rate, the measured fan rotation When the speed increase rate is less than the set fan rotation speed increase rate, it is possible to detect that a fan belt slip has occurred.

  A fourth characteristic configuration of the present invention is that the slip detection means is configured to be able to change detection sensitivity to slip of the cooling fan.

  According to this configuration, it is possible to detect a slight slip of the fan belt in the slip detection unit by changing the detection sensitivity of the slip detection unit to a higher side. Conversely, the detection sensitivity of the slip detection means can be changed to a low side, and detection of slight slip of the fan belt can be eliminated in the slip detection means. That is, for example, the fan belt abnormality can be appropriately determined by changing the sensitivity of slip detection in accordance with the user's request or situation.

The fifth characteristic configuration of the present invention is an environmental temperature measuring means for measuring an environmental temperature at an installation location of the fan belt,
And a detection sensitivity correction unit that corrects the detection sensitivity of the slip detection unit based on the measurement result of the environmental temperature measurement unit.

  According to this configuration, since the ease of occurrence of fan belt slip is also affected by the environmental temperature at the location where the fan belt is installed, the environmental temperature is measured by the environmental temperature measuring means, and the measurement result If the detection sensitivity of the slip detection means is corrected based on this, the slip detection of the fan belt by the slip detection means can be performed with high accuracy.

According to a sixth characteristic configuration of the present invention, as the slip detection means, the occurrence of slip of the fan belt is detected within a rated rotation speed maintaining period while the rotation speed of the engine is maintained at the rated rotation speed. Second slip detecting means,
The belt state determination means can determine the state of the fan belt in a first determination mode using a detection result of the first slip detection means and a second determination mode using a detection result of the second slip detection means. It is in the point which is comprised.

According to this configuration, since the second slip detection means is provided separately from the first slip detection means, the abnormality of the fan belt can be reliably determined by the belt state determination means. That is, when the fan belt abnormality proceeds from the initial abnormality within the rated rotation speed maintaining period in which the engine rotation speed is maintained at the rated rotation speed, the fan belt slips. Therefore, when it is detected by the second slip detection means that the fan belt slips within the rated rotation speed maintaining period, the belt state determination means causes an abnormality that has progressed from the initial abnormality to the fan belt. It can be determined that there is.
In the first determination mode, the belt state determination unit can appropriately determine the initial abnormality of the fan belt based on the detection result of the first slip detection unit as described above. In addition, based on the detection result of the second slip detection means, it is possible to reliably determine an abnormality that has progressed beyond the initial abnormality of the fan belt. For example, the determination result may be used to adjust or replace the fan belt. Users can be urged to perform reliable maintenance.

Combine side view Schematic configuration diagram of the engine and its control device mounted on the combine Flow chart showing control flow of control device

Embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a combine (an example of a work machine) 100 according to the present embodiment includes a traveling machine body 1, an engine 10 as a power source, a cabin 4 having a driver's seat and a control unit, and the like. The traveling machine body 1 is provided with a crawler-type traveling unit 2 that travels the traveling machine body 1 as an operation unit of the traveling system. Further, the traveling machine body 1 includes, as an operation unit of the work system, a harvesting unit 3 that harvests grain cereals at the front of the traveling machine body 1, a threshing unit 5 that threshs the harvested cereal grains, a grain after threshing, and Sorting unit 7 that sorts out unwanted items, storage unit 6 that stores the selected grains, swivelable discharge auger 8 that discharges the grains stored in the storage unit 6, and waste that processes the waste after threshing A coffin processing unit 9 and the like are provided.

  Such a combine 100 is provided with a power transmission mechanism 20 for transmitting the power of the engine 10 to various operating parts B as shown in FIG. The power transmission mechanism 20 includes an input shaft 21 to which rotational power of the output shaft 11 of the engine 10 is input through the belt 16, an output shaft 23 that outputs rotational power to the operating unit B, the input shaft 21, and the output shaft. And a work clutch 22 that can be connected and disconnected. That is, when the state of the work clutch 22 is in a connected state in which the input shaft 21 and the output shaft 23 are connected, the rotational power of the engine 10 is transmitted to the various operating parts B. On the other hand, when the state of the work clutch 22 is in a disengaged state in which the input shaft 21 and the output shaft 23 are disengaged, transmission of rotational power to the various operating parts B is interrupted.

  The combine 100 is provided with a control device 30 that performs operation control of various operation parts B, rotation speed control of the engine 10, and the like. The control device 30 receives an operation signal of the work clutch lever 40 that is switched between an ON state and an OFF state. When the work clutch lever 40 is operated (from when the operation is switched to the ON state until when it is switched to the OFF state), the control device 30 changes the state of the work clutch 22 from the non-connected state to the connected state. And the rotational power of the engine 10 is transmitted to the various operating parts B. On the other hand, when the work clutch lever 40 is not operated (between the time of switching operation to the OFF state and the time of switching operation to the ON state), the control device 30 changes the state of the work clutch 22 from the connected state to the disconnected state. And the transmission of the rotational power of the engine 10 to the various operating parts B is interrupted. That is, the work clutch lever 40 functions as an operation unit A that performs a transmission operation of the power of the engine 10 to the various operation units B.

  The control device 30 is connected to a display operation unit 45 such as a touch panel installed in the cabin 4 (see FIG. 1). The control device 30 can display various information on the display operation unit 45 and the display operation unit. Input of various operation signals from 45 can be accepted.

  The engine 10 is provided with a cooling fan 12 capable of blowing cooling air to a radiator (not shown). The cooling fan 12 is rotationally driven when the rotational power of the output shaft 11 of the engine 10 is transmitted via the fan belt 15. Further, the fan belt 15 is provided in a form that transmits the rotational power of the engine 10 to the alternator 13 for power generation.

The engine 10 is provided with various sensors 17, 18, and 19, and the measurement results of these sensors 17, 18, and 19 are input to the control device 30.
That is, the temperature sensor 17 (an example of an environmental temperature measuring unit) cools the temperature (an example of the environmental temperature) of the engine coolant CW circulating through, for example, a water jacket (not shown) as the environmental temperature at the installation location of the fan belt 15. It is a sensor that measures water temperature. In the present embodiment, the temperature of the cooling water CW is used as an example of the environmental temperature that affects the ease of occurrence of slipping of the fan belt 15, but the present invention is not limited to that configuration. Other environmental temperatures such as engine temperature and outside air temperature may be used.
The rotational speed sensor 18 is a sensor that measures the rotational speed of the output shaft 11 as the engine rotational speed. Furthermore, the rotation speed sensor 19 (an example of a fan rotation speed measuring unit) is a sensor that measures the rotation speed of the cooling fan 12 as the fan rotation speed.

The control device 30 functions as auto-decel control means 31 by executing a predetermined program.
The auto-decel control means 31 performs a decel control that maintains the rotational speed of the engine 10 at a predetermined low rotational speed when the work clutch lever 40 as the operation unit A is not operated. That is, in the deceleration control, when the work clutch lever 40 is switched from the ON state to the OFF state, for example, or when the work clutch lever 40 is maintained in the OFF state for a predetermined time, the work clutch lever 40 is Recognize that it is not operating. Then, when it is recognized that the work clutch lever 40 is in a non-operating state, the rotation speed of the engine 10 is maintained at a low rotation speed, and noise and fuel consumption of the engine 10 are reduced.

  Further, the auto-decel control means 31 increases the rotational speed of the engine 10 from the low rotational speed to a predetermined rated rotational speed higher than that when the work clutch lever 40 as the operation section A is operated. That is, for example, when the work clutch lever 40 is operated from the OFF state to the ON state, it is recognized that the work clutch lever 40 is in the operation state. When it is recognized that the work clutch lever 40 is in the operating state, the rotational speed of the engine 10 is returned to the rated rotational speed, and the power of the engine 10 is appropriately transmitted to the operating part B.

  Immediately after the operation clutch lever 40 is operated from the OFF state to the ON state, the rotational speed of the engine 10 increases rapidly from the low rotational speed toward the rated rotational speed. Furthermore, while the work clutch lever 40 is maintained in the ON state, the rotational speed of the engine 10 is maintained at the rated rotational speed.

  In the present embodiment, a period during which the rotation speed of the engine 10 increases from the low rotation speed toward the rated rotation speed by the auto-decel control means 31 is referred to as a “rotation speed increase period”. A period during which the rotation speed of the engine 10 is maintained at the rated rotation speed is referred to as a “rated rotation speed maintenance period”.

  The above is the basic configuration of the combine 100 of the present embodiment. Furthermore, the control device 30 of the combine 100 of the present embodiment is configured to appropriately determine the initial abnormality of the fan belt 15 while adopting a rational configuration. The detailed configuration will be described below with reference to FIGS.

The control device 30 functions as first slip detection means 32, second slip detection means 33, detection sensitivity correction means 34, and belt state determination means 35 by executing a predetermined program.
The first slip detection means 32 and the second slip detection means 33 are configured as slip detection means for detecting the occurrence of slip of the fan belt 15 that transmits the power of the engine 10 to the cooling fan 12. The display operation unit 45 is configured to be capable of executing a selection operation for selecting the first determination mode and the second determination mode as the determination mode of the state of the fan belt 15, and the selection result is determined by the control device. 30.

  When the first mode is selected (steps # 1 and # 10 in FIG. 3), the control device 30 detects whether or not the fan belt 15 has slipped by the first slip detection means 32 (FIG. 3). 3 steps # 10 to # 13). On the other hand, when the second mode is selected (steps # 1 and # 20 in FIG. 3), the control device 30 detects whether or not the fan belt 15 has slipped by the second slip detection means 33. (Steps # 21 to # 23 in FIG. 3).

  The belt state determination unit 35 determines whether or not the fan belt 15 is abnormal based on the detection results of the slip detection units 32 and 33. Specifically, when the first mode is selected (steps # 1 and # 10 in FIG. 3), the detection result of the first slip detection means 32 (step # 13 in FIG. 3) is used to detect the fan belt 15. Determine the state. On the other hand, when the second mode is selected (steps # 1 and # 20 in FIG. 3), the state of the fan belt 15 is changed using the detection result of the second slip detection means 33 (step # 23 in FIG. 3). judge.

  When it is determined that the fan belt 15 is abnormal (step # 30 in FIG. 3), an alarm process (step # in FIG. 3) for outputting alarm information for notifying the user of the fact to the display operation unit 45. 31) is executed. On the other hand, when it is determined that there is no abnormality in the fan belt 15 (step # 32 in FIG. 3), the present control flow ends without executing the alarm processing as described above.

  The first slip detection means 32 detects the occurrence of slip of the fan belt 15 during the rotation speed increase period in which the rotation speed of the engine 10 increases from the low rotation speed to the rated rotation speed. Specifically, it is determined whether or not it is within the rotational speed increase period during which the rotational speed of the engine 10 is being increased by the auto-decel control means 31 (step # 11 in FIG. 3). If it is within the rotation speed increase period (Yes in step # 11 in FIG. 3), the rotation speed of the cooling fan 12 measured by the rotation speed sensor 19 is increasing at a predetermined timing within the rotation speed increase period. Obtained as the fan rotation speed Fu (step # 12 in FIG. 3). It should be noted that the predetermined timing within the rotation speed increase period is set to a timing when a predetermined time (for example, 1 second) has elapsed since the increase in the rotation speed of the engine 10 is started.

  When the rising fan rotation speed Fu is lower than the predetermined set fan rotation speed Fuo (Yes in step # 13 in FIG. 3), it is detected that the fan belt 15 has slipped. The set fan rotation speed Fuo is set in advance as the rotation speed of the engine 10 at a predetermined timing within the rotation speed increase period or a slightly lower rotation speed. Further, the rotation speed of the engine 10 is automatically increased by the auto-decel control means 31. Therefore, the rotational speed of the engine 10 at the predetermined timing can be set as a known value in advance without using the measurement result of the rotational speed sensor 18.

Even if there is only a relatively small initial abnormality in the fan belt 15 within the rotation speed increase period while the rotation speed of the engine 10 is increased from the low rotation speed to the rated rotation speed by the auto-decel control means 31, the fan The belt 15 is likely to slip.
Therefore, when the slip of the fan belt 15 is detected by the first slip detection means 32, it can be recognized that the fan belt 15 has at least an initial abnormality. The detection of the slip of the fan belt 15 is determined as an abnormality of the fan belt 15 by the belt state determination means 35 (step # 30 in FIG. 3), and notified to the user by an alarm process (step # 31 in FIG. 3). To do. Then, the user can be informed that there is at least an initial abnormality in the fan belt 15, and the maintenance such as the adjustment or replacement of the fan belt 15 can be promptly performed.

  The second slip detection means 33 detects the occurrence of slip of the fan belt 15 within the rated rotation speed maintaining period while the rotation speed of the engine 10 is maintained at the rated rotation speed. Specifically, it is determined whether or not it is within the rotation speed maintaining period after the rotation speed of the engine 10 is increased by the auto-decel control means 31 (step # 21 in FIG. 3). If it is within the rotation speed maintenance period (Yes in step # 21 in FIG. 3), the rotation speed of the cooling fan 12 measured by the rotation speed sensor 19 at a predetermined timing within the rotation speed maintenance period is maintained. Obtained as the rotation speed Fr (step # 22 in FIG. 3). The predetermined timing within the rotation speed maintaining period is set as a predetermined time interval timing, for example.

  When the maintenance fan rotation speed Fr is less than the predetermined set fan rotation speed Fro (Yes in step # 23 in FIG. 3), it is detected that the fan belt 15 has slipped. The set fan rotation speed Fro is set in advance as the rated rotation speed of the engine 10 or a slightly lower rotation speed. Further, the rated rotational speed of the engine 10 can be recognized as a known one in advance without using the measurement result of the rotational speed sensor 18. For example, the rotational speed of the engine 10 measured by the rotational speed sensor 18 is determined. You can use it.

Within the rotation speed maintenance period after the rotation speed of the engine 10 is increased by the auto-decel control means 31, if the fan belt 15 has only a relatively small initial abnormality, the fan belt 15 is unlikely to slip. However, when the abnormality progresses, the fan belt 15 slips.
Therefore, when the slip of the fan belt 15 is detected by the second slip detection means 33, it can be recognized that the fan belt 15 has an abnormality that has progressed more than the initial abnormality. The detection of the slip of the fan belt 15 is determined as an abnormality of the fan belt 15 by the belt state determination means 35 (step # 30 in FIG. 3), and notified to the user by an alarm process (step # 31 in FIG. 3). To do. Then, the user can be informed that the fan belt 15 has a relatively serious abnormality, and can be urged to carry out maintenance such as adjustment and replacement of the fan belt 15 with certainty.

The first slip detection means 32 and the second slip detection means 33 described above are configured so that the detection sensitivity of the cooling fan 15 to the slip can be changed.
That is, the slip detection means 32 and 33 increase and decrease the set fan rotation speeds Fuo and Fro which are compared as threshold values of the rotation speeds Fu and Fr of the cooling fan 12 measured by the rotation speed sensor 19, and have a detection sensitivity. It can be changed. For example, when lowering the detection sensitivity of the slip detection means 32, 33, the set fan rotation speeds Fuo, Fro are decreased so that the rotation speeds Fu, Fr of the cooling fan 12 are less than the set fan rotation speeds Fuo, Fro. It is assumed that it is difficult to become. Conversely, when the detection sensitivity of the slip detection means 32, 33 is increased, the set fan rotation speeds Fuo, Fro are increased so that the rotation speeds Fu, Fr of the cooling fan 12 become the set fan rotation speeds Fuo, Fro. It will be in the state where it is likely to become less than.

Further, the detection sensitivity correction unit 34 corrects the detection sensitivities of the slip detection units 32 and 33 based on the temperature of the cooling water CW measured by the temperature sensor 17. That is, the ease with which the fan belt 15 slips is also affected by the environmental temperature at the location where the fan belt 15 is installed. Specifically, the lower the environmental temperature, the more likely the slip of the fan belt 15 that is not caused by the abnormality of the fan belt 15 occurs. Further, the temperature of the cooling water CW can be used as the environmental temperature. For these reasons, the detection sensitivity correction means 34 detects slippage of the fan belt 15 that is not caused by the abnormality of the fan belt 15, and the slip detection means 32, 33 decreases as the temperature of the cooling water CW decreases. Is set to the low side (dull side).
Further, the detection sensitivity of the slip detection means 32 and 33 may be configured so that the user can arbitrarily change the setting by operating the display operation 45.

[Another embodiment]
Other embodiments of the present invention will be described. Note that the configuration of each embodiment described below is not limited to being applied independently, and can be applied in combination with the configuration of another embodiment.

(1) In the above embodiment, the slip detection means 32, 33 detects the slip of the fan belt 15 using the measurement result of the rotational speed of the cooling fan 12, but the present invention is limited to that configuration. Instead, another measurement result may be used. For example, the slip of the fan belt 15 can be detected using measurement results such as the rotational speed of the alternator 13 and the feed speed of the fan belt 15 itself.

(2) In the above embodiment, the first slip detection means 32 compares the rising fan rotation speed Fu with the set fan rotation speed Fuo at a predetermined timing within the rotation speed increase period, and detects the slip of the fan belt 15. Although detected, the present invention is not limited to the configuration, and may be configured to detect slip in another form. For example, the slip of the fan belt 15 can be detected using the rate of increase in the rotational speed of the cooling fan 12 within the rotational speed increase period. With this configuration, it is possible to detect the slip of the fan belt 15 with higher accuracy than in the case of detecting using the rising fan rotation speed at a predetermined timing. The details of the detection method will be described below.

  The first slip detection means 32 rotates, for example, the rotation speed of the cooling fan 12 immediately after the start of the increase in the rotation speed of the engine 10 and the rotation speed of the cooling fan 12 after a predetermined time has elapsed within the rotation speed increase period. Measurement is performed by the speed sensor 19, and the rate of increase of the rotation speed of the cooling fan 12 during the rotation speed increase period is calculated using each of the measured rotation speeds, and is acquired as the fan rotation speed increase rate.

  When the fan rotation speed increase rate is less than a predetermined set fan rotation speed increase rate, it is detected that the fan belt 15 has slipped. The set fan rotation speed increase rate is set in advance as an increase rate of the engine 10 rotation speed within the rotation speed increase period or a slightly lower increase rate than that. Further, the rotation speed of the engine 10 is automatically increased by the auto-decel control means 31. Therefore, the increase rate of the rotational speed of the engine 10 can be set as a known value in advance without using the measurement result of the rotational speed sensor 18.

10 Engine 12 Cooling fan 15 Fan belt 16 Belt 17 Temperature sensor (environmental temperature measuring means)
19 Rotational speed sensor (fan rotational speed measuring means)
30 control device 31 auto-decel control means 32 first slip detection means 32 slip detection means 33 second slip detection means 33 slip detection means 34 detection sensitivity correction means 35 belt state determination means 100 combine A operation part B action part Fr maintenance fan rotation speed Fro Setting fan rotation speed Fu Rising fan rotation speed Fuo Setting fan rotation speed

Claims (6)

In a work machine including an engine that generates power, an operation unit that operates by power of the engine, and an operation unit that performs transmission operation of the power of the engine to the operation unit,
Slip detecting means for detecting occurrence of slip of the fan belt for transmitting the power of the engine to a cooling fan;
A control device for a work machine, comprising: a belt state determination unit that determines a state of the fan belt based on a detection result of the slip detection unit;
When the operation unit is not operated, a deceleration control is performed to maintain the engine rotation speed at a predetermined low rotation speed, and the engine rotation speed is increased from the low rotation speed to a predetermined value higher than the operation speed when the operation unit is operated. Equipped with auto-decel control means to increase the rated rotational speed of
As the slip detection means, there is provided first slip detection means for detecting occurrence of slip of the fan belt during a rotation speed increase period while the rotation speed of the engine is increased to the rated rotation speed by the auto-decel control means. Work machine control device. Fan rotation speed measuring means for measuring the rotation speed of the cooling fan,
The first slip detection means acquires the cooling fan rotation speed at a predetermined timing within the rotation speed increase period as the rising fan rotation speed by the fan rotation speed measurement means, and the rising fan rotation speed is 2. The work machine control device according to claim 1, which is means for detecting that the fan belt slips when the rotation speed is lower than a predetermined set fan rotation speed. Fan rotation speed measuring means for measuring the rotation speed of the cooling fan,
The first slip detection means acquires, as the fan rotation speed increase rate, an increase rate of the cooling fan rotation speed within the rotation speed increase period by the fan rotation speed measurement means, and the fan rotation speed increase rate is predetermined. 2. The work machine control device according to claim 1, wherein the control device is a means for detecting that the fan belt has slipped when the fan rotational speed increase rate is less than a set value.   4. The work machine control device according to claim 1, wherein the slip detection unit is configured to be able to change a detection sensitivity of the cooling fan with respect to a slip. 5. Environmental temperature measuring means for measuring the environmental temperature at the installation location of the fan belt;
The work machine control device according to claim 4, further comprising: a detection sensitivity correction unit that corrects a detection sensitivity of the slip detection unit based on a measurement result of the environmental temperature measurement unit. The slip detection means includes second slip detection means for detecting occurrence of slip of the fan belt within a rated rotation speed maintaining period while the rotation speed of the engine is maintained at the rated rotation speed,
The belt state determination means can determine the state of the fan belt in a first determination mode using a detection result of the first slip detection means and a second determination mode using a detection result of the second slip detection means. The control device for a work machine according to any one of claims 1 to 5, which is configured as follows.

Images