Travel control device and travel control system

Abstract

To provide a traveling device and a travel control system capable of automatically switching a traveling stage of a crawler in turning operation, while suppressing increase in design, manufacture and maintenance costs.SOLUTION: When a travel second speed mode has been set (S06: YES), a turning determination unit 43 determines whether a calculated difference value is equal to or more than a high-speed stage determination value, that is, whether the value is 25% or more of the maximum value of an operating command value or a spool operation amount (S07). When the value is 25% or more (S07: YES), it is determined that the turning operation has been performed, the travel second speed mode is turned off (S08), and a traveling temporary first speed mode is turned on (S09). When the difference value is smaller than 25% of the maximum value (S07: NO), processing does not be performed in particular, and the processing is repeated from the beginning.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a driving control device and a driving control system for industrial machinery. [Background technology]

[0002] Conventionally, industrial machines equipped with a pair of crawlers on the left and right have two travel stages: a first speed that is slow but capable of generating high torque, and a second speed that is slow but capable of running at high speed with low torque. When driving such industrial machinery, the operator may use second gear when the running resistance is low, such as when going straight, and use first gear when turning, when the running resistance increases, thereby improving turning performance.

[0003] The above-mentioned operation of changing the driving speed is performed by operating a speed change switch located near the control lever. However, since the hand must be removed from the control lever in order to operate the speed change switch, it is necessary to stop the industrial machine once, change the speed, and then operate the driving operation again. Even in cases where a driver's seat is provided and the speed change switch is located on the floor, in order to drive smoothly, it is necessary to operate the speed change switch at the right time while operating the control lever. Therefore, a certain level of proficiency is required to perform driving operations that involve speed change operations.

[0004] Therefore, as an element for reducing the burden on the operator during traveling operation, Patent Document 1 discloses a configuration in which an automatic switching valve is provided in the drive circuit of the hydraulic motor. The automatic switching valve automatically switches between low and high speed depending on the magnitude of the load on the motor.

[0005] To briefly explain the structure of the change-over valve disclosed in Patent Document 1, it is equipped with a hollow two-speed spool that controls the flow path to the hydraulic motor and control piston, an external pilot port that sets the hollow two-speed spool to which pressure is supplied by operator input and which sets it to the second speed position, a first small diameter spool and a second small diameter spool to which the driving pressure of the hydraulic motor is supplied, and a spring that returns the hollow two-speed spool to the first speed position when no gear shifting operation is being performed.

[0006] In order to perform automatic shifting, this switching valve is designed so that the pressure-receiving area of ​​the second small diameter spool is smaller than the pressure-receiving area of ​​the first small diameter spool. With this structure, when the hydraulic pressure increases with an increase in the load on the hydraulic motor, the operating force applied to the second small diameter spool greatly exceeds the operating force applied to the first small diameter spool, and the resultant force of the second small diameter spool and the spring becomes greater than the resultant force of the operating forces applied to the first small diameter spool and the external pilot port, causing the hollow second-speed spool to move to the position (first-speed position) shown in Figure 1 of Patent Document 1. Therefore, even if the automatic shift valve is in the second gear position, when the drive pressure of the hydraulic motor exceeds a predetermined value, the travel stage is automatically switched to first gear. In this way, the travel stage is switched by a change in pressure applied to the hydraulic motor, so the operator can perform travel operations without performing operations to switch the travel stage. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP2015-017684 Public Relations Summary of the Invention [Problem to be solved by the invention]

[0008] However, in such an automatic transmission mechanism, in addition to the supply pressure to the external pilot port and the pressure-receiving area ratio between the first small diameter spool and the second small diameter spool, the spring force must be set to an appropriate value, and the structure can easily become complicated because many flow paths are connected to the automatic switching valve. This causes an increase in manufacturing costs and maintenance costs of the hydraulic motor unit. Furthermore, when applying to a model with a different hydraulic motor size, or when making minor changes to the same model, the above structure needs to be redesigned, making it difficult to reduce design costs.

[0009] In view of the above circumstances, the present invention aims to provide a traveling device and a traveling control system that can automatically switch the traveling stage of the crawler during turning operations while suppressing increases in design, manufacturing, and maintenance costs. [Means for solving the problem]

[0010] A first invention is a travel control device for an industrial machine that has a crawler on each of the left and right sides of a body, each of the crawlers being driven by a fluid pressure motor equipped with a speed change mechanism, the travel control device comprising: an operation unit for operating the left and right crawlers; a turning determination unit for determining whether a turning operation has been performed on the operation unit; and a control unit that performs control to switch the travel stage of the fluid pressure motor based on the determination of the turning determination unit, wherein the fluid pressure motor is capable of setting the travel stage to at least two stages, a low speed stage and a high speed stage, and the control unit sets the travel stage of the fluid pressure motor to the low speed stage while the turning determination unit determines that a turning operation is being performed.

[0011] A second invention is a driving control device characterized in that the control unit described in the first invention is configured so that the driving mode is set to a low-speed mode or a high-speed mode by operation of the operator, and in the low-speed mode, the transmission mechanism is set to the low-speed mode, and in the high-speed mode, the transmission mechanism is set to the high-speed mode, and in the high-speed mode, while the turning judgment unit determines that a turning operation is being performed, the driving mode is set to the low-speed mode as a temporary low-speed mode, and when in the temporary low-speed mode, if the turning judgment unit determines that a turning operation is not being performed, the driving mode is set to the driving mode selected by the operator.

[0012] A third invention is a travel control device characterized in that the industrial machine described in the first invention is provided with a control valve for adjusting the direction and flow rate of the working fluid supplied to the fluid pressure motor, the control valve having a left spool valve connected to the fluid pressure motor corresponding to the left crawler and a right spool valve connected to the fluid pressure motor corresponding to the right crawler built in, the left spool valve is provided with a left operation amount detection unit that detects the operation amount of a spool, and the right spool valve is provided with a right operation amount detection unit that detects the operation amount of a spool, and the turning determination unit determines that a turning operation is being performed when a predetermined difference occurs between the detection value of the left operation amount detection unit and the detection value of the right operation amount detection unit.

[0013] A fourth invention is a driving control device characterized in that the specified difference described in the third invention is a specified value that is greater than or equal to 15% and less than or equal to 25% of the maximum drive amount of the right spool valve and the left spool valve.

[0014] A fifth invention is a driving control device characterized in that the specified difference described in the fourth invention is set to a high speed gear determination value when the fluid pressure motor is set to a high speed gear, and is set to a low speed gear determination value when the fluid pressure motor is set to a low speed gear, and the high speed gear determination value is set to a value greater than the low speed gear determination value.

[0015] A sixth invention is a driving control device characterized in that the fluid pressure motor described in any one of the first to fifth inventions is connected to a drive flow path that supplies pressure oil to the fluid pressure motor and a speed change flow path for operating the transmission mechanism, the transmission mechanism changes the travel stage by hydraulic fluid pressure, the speed change flow path is equipped with a switching valve which is a pilot valve that controls the operation of the transmission mechanism, and a speed change control valve which is a solenoid valve that controls the operation of the switching valve, the switching valve is switchable between a high speed position which sets the travel stage to a high speed stage and a low speed position which sets the travel stage to a low speed stage, the speed change control valve is switchable between a high speed command position which connects a pilot port of the switching valve to a pump and a low speed command position which connects the pilot port to a hydraulic fluid tank, and the control unit sets the speed change control valve to the low speed command position while the turning determination unit determines that a turning operation is being performed.

[0016] A seventh invention is a travel control system comprising an industrial machine having a crawler on each of the left and right sides of a body, each of the crawlers being driven by a fluid pressure motor equipped with a speed change mechanism, and a remote control device having an operation unit for inputting an operation command value for the crawler, the travel control system further comprising a turning determination unit that determines whether a turning operation has been performed based on the operation command value transmitted from the remote control device, and a control unit that controls switching of the travel stage of the fluid pressure motor based on the determination of the turning determination unit, the fluid pressure motor being capable of setting the travel stage to at least two stages, a low speed stage and a high speed stage, and the control unit setting the travel stage of the crawler to the low speed stage while the turning determination unit determines that a turning operation is being performed.

[0017] An eighth invention is a driving control system characterized in that the control unit described in the seventh invention is configured such that the driving mode is set to a low-speed mode or a high-speed mode by operation of the operator, and in the low-speed mode, the transmission mechanism is set to the low-speed mode, and in the high-speed mode, the transmission mechanism is set to the high-speed mode, and in the high-speed mode, while the turning judgment unit determines that a turning operation is being performed, the driving mode is set to the low-speed mode as a temporary low-speed mode, and when in the temporary low-speed mode, if the turning judgment unit determines that a turning operation is not being performed, the driving mode is set to the driving mode selected by the operator.

[0018] A ninth invention is a driving control system characterized in that the turning determination unit described in the seventh invention determines that a turning operation is being performed when a predetermined difference occurs between an operation command value of the fluid pressure motor corresponding to the left crawler input to the remote control device and an operation command value of the fluid pressure motor corresponding to the right crawler.

[0019] A tenth aspect of the present invention is a cruise control system according to the ninth aspect of the present invention, characterized in that the predetermined difference is a predetermined value that is equal to or greater than 15% and equal to or less than 25% of the maximum value of the operation command value.

[0020] An eleventh invention is a driving control system characterized in that the specified difference described in the tenth invention is set to a high speed gear determination value when the fluid pressure motor is set to a high speed gear, and is set to a low speed gear determination value when the fluid pressure motor is set to a low speed gear, and the high speed gear determination value is set to a value greater than the low speed gear determination value.

[0021] A twelfth invention is a driving control system characterized in that the fluid pressure motor according to any one of the seventh to eleventh inventions is connected to a drive flow path that supplies pressure oil to the fluid pressure motor and a speed change flow path for operating the transmission mechanism, the transmission mechanism changes the travel stage by hydraulic fluid pressure, the speed change flow path includes a switching valve which is a pilot valve that controls the operation of the transmission mechanism, and a speed change control valve which is a solenoid valve that controls the operation of the switching valve, the switching valve is switchable between a high speed position for setting the travel stage to a high speed position and a low speed position for setting the travel stage to a low speed position, the speed change control valve includes a speed change control valve that is switchable between a high speed command position for connecting a pilot port of the switching valve to a pump and a low speed command position for connecting the pilot port to a hydraulic fluid tank, and the control unit sets the speed change control valve to the low speed command position while the turning determination unit determines that a turning operation is being performed. Effect of the Invention

[0022] According to the present invention, it is possible to provide a traveling device and a traveling control system that can automatically switch the traveling stage of a crawler and suppress increases in manufacturing and maintenance costs. [Brief description of the drawings]

[0023] [Figure 1] 1 is a side view of a crawler crane equipped with a traveling device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram of an operation section of the crawler crane shown in FIG. [Diagram 3] FIG. 2 is a diagram of a remote control for a crawler crane according to an embodiment of the present invention. [Figure 4] 1 is a hydraulic circuit diagram of a crawler crane according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a hydraulic circuit diagram of a control valve of the crawler crane according to the embodiment of the present invention. [Figure 6] FIG. 5 is a diagram of a motor unit portion extracted from the hydraulic circuit diagram shown in FIG. 4. [Figure 7]FIG. 7 is a hydraulic circuit diagram when the motor unit shown in FIG. 6 sets the hydraulic motor to second speed. [Figure 8] 1 is a block diagram showing a configuration of a driving control device and a driving control system according to an embodiment of the present invention; [Figure 9] 4 is a flowchart showing a method for controlling a switching valve according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings, taking as an example a crawler crane, which is a type of industrial machine and has crawlers on the left and right sides of its body. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals, and duplicated explanations are omitted. It should be noted that the drawings are schematic. Therefore, it should be noted that the relationship between thickness and planar dimensions, ratios, etc. may differ from the actual ones, and the drawings also include parts with different dimensional relationships and ratios. In addition, the embodiments shown below are examples of devices and methods for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention does not specify the materials, shapes, structures, displays, etc. of the components to the embodiments below.

[0025] In the following explanations and drawings relating to the configuration of industrial machinery, unless otherwise specified, the direction in which the machine moves forward will be referred to as the "front side of the machine" or simply "front side", and the direction in which the machine moves backward will be referred to as the "rear side of the machine" or simply "rear side". Additionally, the left hand side of the machine from the driver will be referred to as the "left side of the machine" or simply "left side", and the right hand side will be referred to as the "right side of the machine" or simply "right side". Similarly, "upper side" and "lower side" are defined based on the driver sitting in the driver's seat. When no particular direction is specified, the terms "forward / backward direction of the machine", "left / right direction of the machine", and "up / down direction of the machine" may be used. Unless otherwise specified, the crawler crane will be described as being in a traveling state in which the crane equipment has rotated to a position facing rearward along the fore-and-aft direction of the machine body, the boom has been lowered to a horizontal angle, and the outrigger equipment is stored.

[0026] <Crawler crane structure> As shown in FIG. 1, the crawler crane 1 is provided with a pair of crawlers 2 on the left and right sides of the lower body, which are driven by a hydraulic motor M and have tracks that circulate along the fore-aft direction of the body. When it is necessary to distinguish between the left and right, the crawler 2 may be described as a left crawler 2L (FIG. 4) and a right crawler 2R (FIG. 4). The hydraulic motor M is a variable displacement piston motor, and by changing the flow rate of hydraulic oil required for one rotation using a speed change mechanism, it is possible to change the rotation speed without changing the discharge flow rate from the pump. The crawler crane 1 according to this embodiment is set to two travel stages, with the first stage being set as the low speed stage and the second stage being set as the high speed stage. An outrigger unit 4 and a crane unit 5 are provided on the upper side of the machine body. An engine and the like are accommodated in a rear part 6 of the machine body, and an operating unit 10 shown in FIG. Although not shown, if the crawler crane 1 is a large model, a driver's seat for an operator may be provided at the rear part 6 of the machine body.

[0027] The crane apparatus 5 comprises a column 7 which can rotate about an axis along the up-down direction of the machine body, and a telescopic boom 8 which is supported on the upper end of the column 7 so as to be able to be raised and lowered about an axis along the left-right direction of the machine body, and a hook HO connected to a wire rope extending from a winch is suspended from the tip of the telescopic boom 8.

[0028] The crawler crane 1 is capable of changing the width between the left and right crawlers 2. Although not shown, a hydraulic cylinder is built into the bottom of the machine body, and by extending and contracting this hydraulic cylinder, the crawler 2 can move from a width approximately the same as the machine body width to a position where it protrudes from the left and right sides of the machine body. In this way, by making the width between the left and right crawlers 2 variable, the width can be narrowed to allow entry when traveling on narrow ground, and the width can be widened on rough ground to ensure stability.

[0029] Although details will be described later, as shown in Fig. 8, the crawler crane 1 is equipped with a controller 40. The controller 40 controls the operation of the crawler crane 1, and when operation is being performed by the remote control device 20 described next, it operates the left crawler 2L and right crawler 2R based on an operation command signal, and also controls the speed change of the crawler 2.

[0030] <Structure of the control unit> Next, the operation section of the crawler crane 1 will be described with reference to FIG. The crawler crane 1 is provided with an operation unit 10 at the rear body 6, in which a left lever 11, a right lever 12, an accelerator lever 13 and a two-speed changeover switch 14 are all arranged together. The left lever 11 and the right lever 12 are attached to the center of the operation unit 10, with the stand lever 15 disposed on the left side and the lock lever 16 disposed on the right side. The accelerator lever 13 is disposed further to the right of the lock lever 16, and the two-speed changeover switch 14 is disposed further to the left of the stand lever. Therefore, the operator operates the left lever 11 and the two-speed changeover switch with his left hand, and the right lever 12 and the accelerator lever 13 with his right hand. By operating the two-speed changeover switch 14, it is possible to switch the crawler crane 1 between a single-speed traveling mode, which is a low-speed stage mode, and a two-speed traveling mode, which is a high-speed stage mode. The stand lever 15 and the lock lever 16 are safety devices for fixing the left lever 11 and the right lever 12 when in the working position.

[0031] Although not shown, when the crawler crane 1 is equipped with a driver's seat, an accelerator pedal is disposed to the right of the right lever 12 on the floor surface of the driver's seat, and a two-speed changeover switch 14 is disposed to the left of the left lever 11. Therefore, the operator operates the accelerator pedal with his right foot and the two-speed changeover switch 14 with his left foot.

[0032] <Remote Control Device> Next, the remote control will be described with reference to FIG. The remote controller 20 includes a grip portion 21 and a remote controller 22. A battery pack (not shown) is inserted into the grip portion 21.

[0033] The remote control unit 22 is equipped with an information display unit 23 that displays information such as the selected travel mode, and is equipped at its bottom with a left stick 24, a right stick 25, and a setting switch 26. The left stick 24 and right stick 25 are used not only for operating the mobile crane 1 to travel as described below, but also for operating work equipment such as the crane unit 5 and the outrigger unit 4. The operator can freely change the object of operation by operating the setting switch 26 to change the setting. Although not shown in FIG. 3, the remote controller 20 is equipped with a transmitter 27 for transmitting an operation signal to the crawler crane 1.

[0034] The left stick 24 and the right stick 25 are joysticks equipped with a two-axis sensor at their base. The two-axis sensor consists of an X-axis sensor that detects tilt in the left-right direction and a Y-axis sensor that detects tilt in the up-down direction, and detects the direction and magnitude of tilt of the stick in the form of X and Y coordinate values. In addition, when no external force is applied, a biasing force is applied so that the stick automatically returns to the origin position where the input values ​​on both the X-axis and Y-axis are 0.

[0035] Specifically, the initial position is the origin (X:0, Y:0), and the position of the Cartesian coordinate system is expressed as a numerical value in the range of -255 to +255 with the left-right direction being the X-axis and the up-down direction being the Y-axis. For example, when the left stick 24 is tilted to the upper right to about half of the range of motion, it is expressed as a numerical value as (X:+122, Y:+122). When the left stick 24 is tilted significantly to the left and slightly downward, it is expressed as a numerical value as (X=-200, Y=-30).

[0036] <Remote control device operation method> In the remote controller 20, the left crawler 2L corresponds to the operation of the left stick 24, and the right crawler 2R corresponds to the operation of the right stick 25. With this operation method, when the stick is tilted forward and a +Y operation command value is input, the crawler 2 moves in the forward direction. Therefore, to move straight, the left stick 24 and right stick 25 are tilted in the same direction to the same angle. To turn, the tilt of the stick on the side to turn is reduced to slow down the robot, generating a difference in rotational speed between the crawlers.

[0037] In the remote controller 20 according to this embodiment, the X-axis of the operation command values ​​is assigned to widening and narrowing operations of the crawler 2. Specifically, when an operation command value of -X is input to the left stick 24 and an operation command value of +X is input to the right stick 25, widening is performed, and when an operation command value of +X is input to the left stick 24 and an operation command value of -X is input to the right stick 25, narrowing is performed. That is, when widening the width, the left stick 24 or the right stick 25 is tilted outward, and when narrowing the width, the left stick 24 or the right stick 25 is tilted inward.

[0038] <Hydraulic circuit of crawler crane> Next, the hydraulic circuit of the crawler crane 1 will be described with reference to Fig. 4. Note that the hydraulic circuit other than that for the crawler will not be described or illustrated. The hydraulic circuit of the crawler includes a pump P, a control valve C, a left motor unit LMU, and a right motor unit RMU. The pump P is connected to the control valve C, which is connected to the left motor unit LMU and the right motor unit RMU. Further, a shift control valve 32 is connected to the left motor unit LMU and the right motor unit RMU.

[0039] Inside the control valve C, there are a left spool valve SL and a right spool valve SR that are operated by the operating unit 10 and the remote control device 20, and by switching the flow path of the hydraulic oil, the hydraulic motor M is rotated forward, reverse, or stopped. As shown in Fig. 5, the left spool valve SL is connected to a left lever 11 via a double-acting cylinder DCL, and the right spool valve SR is connected to a right lever 12 via a double-acting cylinder DCR. The double-acting cylinders DCL and DCR operate when the crawler crane 1 is operated to travel using the remote control.

[0040] When the operation is performed using the remote controller 20, the crawler crane 1 is set to a radio-controlled operation mode at the start of work, and pairing with the remote controller 20 is performed. When pairing is completed, the remote control valves 101-104, which are solenoid valves shown in Fig. 4, are operated to supply pressure oil to the double-acting cylinder DCL for operating the left spool valve SL and the double-acting cylinder DCR for operating the right spool valve SR. Thereafter, the double-acting cylinders DCL and DCR are operated by controlling the opening and closing of the remote control valves 101-104 based on an operation command signal, thereby operating the spool valves SL and SR, and operating the left crawler 2L and the right crawler 2R. Note that while the remote controller 20 is being operated, the lever also operates in conjunction with the operation of the spool valves SL and SR, and if the lever is operated when the remote controller 20 is not being operated, the operation of the hydraulic motor M is stopped. Such an interlock mechanism prevents malfunction of the remote controller 20 while it is being used.

[0041] Next, the structure of the right motor unit RMU will be described with reference to Fig. 6. Note that since the left motor unit LMU and the right motor unit RMU have the same structure, a description of the left motor unit LMU will be omitted. The right motor unit RMU includes therein a hydraulic motor M, a switching valve 31, and a counterbalance valve CB. A driving flow passage and a speed change flow passage are connected to the hydraulic motor M. However, this definition is merely for convenience, since the driving flow passage and the speed change flow passage are partially connected to each other.

[0042] The drive flow path is a flow path that connects from the counterbalance valve CB to the hydraulic motor M. When hydraulic oil is not being supplied from the control valve C, the counterbalance valve CB is located in a stop position SP where the flow path is not connected, and by stopping the flow of hydraulic oil, the rotation of the hydraulic motor M is stopped. When the counterbalance valve is located in the stop position, no hydraulic pressure is applied to the brake B, so the hydraulic motor M is also stopped by the brake B. When hydraulic oil is supplied from the control valve C, the counterbalance valve CB automatically moves to the forward rotation position FP or the reverse rotation position RP to rotate the hydraulic motor M. Note that Fig. 6 shows the state in which the counterbalance valve CB has moved to the forward rotation position FP.

[0043] The speed change flow path is a flow path that connects the counterbalance valve CB through the shuttle valve SB and the switching valve 31 to the speed change mechanism 33. A speed change control valve 32 is connected to a pilot port of the switching valve 31. The switching valve 31 is a pilot valve that can be switched between a first-speed position LP1, which is a low-speed position, and a second-speed position HP1, which is a high-speed position, and is biased so that the basic position is set to the first-speed position LP1. A pilot port is provided on the second-speed position HP1 side, and the switching valve 31 switches to the second-speed position when the pilot pressure exceeds the biasing force. The downstream side of the flow path is connected to the speed change mechanism 33 of the motor, and the upstream side is connected to the counterbalance valve CB via the shuttle valve SB.

[0044] The shift control valve 32 is a solenoid valve that can be switched between a first speed command position LP2, which is a low speed command position, and a second speed command position HP2, which is a high speed command position, and is biased so that its basic position is set to the first speed command position LP2. When the solenoid is energized, it switches to the second speed command position HP2. The downstream side of the flow path is connected to the pilot port of the switching valve 31, and the upstream side is connected to the control valve C and the hydraulic oil tank T. When the first speed command position LP2 is selected, the pilot port of the switching valve 31 is connected to the hydraulic oil tank T, and when the second speed command position HP2 is selected, a pump is connected to the pilot port of the switching valve 31 to supply pressure oil.

[0045] Since the switching valve 31 is normally positioned in the first gear position LP1, the transmission mechanism 33 is connected to the hydraulic oil tank T and no pressurized oil is supplied, so the drive stage of the hydraulic motor M is maintained in a first gear state, which is a low speed but can generate high torque. When the crawler crane 1 switches to the two-speed traveling mode and the switching valve 31 switches to the second-speed position HP1, pressure oil is supplied from the pump P to the speed change mechanism 33 through the counterbalance valve CB, and the speed change mechanism 33 operates. As a result, the speed change flow path becomes the state shown in Figure 7, and the hydraulic motor M switches to second speed, which has low torque but can provide high speed.

[0046] <Drive control device and drive control system> The configurations of the cruise control device 50 and the cruise control system 60 will be described with reference to FIG. The travel control device 50 is provided on the crawler crane 1 and is composed of an operation unit 10, a control valve C, a controller 40 and the crawler 2. The control valve C is provided with a left operation amount detector 34 that detects the operation amount of the left spool valve SL, and a right operation amount detector 35 that detects the operation amount of the right spool. The controller 40 includes a difference value calculation unit 42, a turning determination unit 43, and a control unit 44. A difference value calculation unit 42 calculates the difference between the amount of operation of the left spool valve SL and the amount of operation of the right spool valve SR, and a turning determination unit 43 determines whether a turning operation is being performed based on the calculation result of the difference value calculation unit 42. Then, a control unit 44 controls the operation of the shift control valve 32 based on the determination result of the turning determination unit 43.

[0047] The travel control system 60 is composed of the crawler crane 1 and the remote control device 20. The remote control device 20 is equipped with a transmitter 27 in addition to the left stick 24 and right stick 25 described above. The controller 40 of the crawler crane 1 is equipped with a receiver 41 in addition to the elements that make up the travel control device 50. When the left stick 24 and the right stick 25 are operated, an operation signal is transmitted from the transmitter 27 and received by the receiver 41. The receiver 41 transmits the received operation signal to a difference value calculation unit 42. The difference value calculation unit 42 then calculates the difference between the operation signals of the left stick 24 and the right stick 25, and based on the calculation result, a turning determination unit 43 determines whether a turning operation is being performed. If it is determined that a turning operation is being performed, the control unit 44 controls the operation of the gear shift control valve 32 in the same manner as the cruise control device 50.

[0048] The operation of the cruise control device 50 and the cruise control system 60 will be specifically described with reference to FIG. First, it is determined whether operation is being performed by the operation unit 10 or the remote controller 20 (S01). In this embodiment, if operation is performed by the operation unit 10 of the vehicle, it is determined that the radio control mode is OFF and the cruise control device 50 operates, and if operation is performed by the remote controller 20, it is determined that the radio control mode is ON and the cruise control system 60 operates.

[0049] If it is determined that the radio control mode is ON (S01: YES), the difference value calculation unit 42 obtains the operation command value transmitted from the transmission unit 27 of the remote controller 20, and calculates the difference between the operation command values ​​of the left stick 24 and the right stick 25 (S02, S03). If it is determined that the radio control mode is OFF (S01: NO), the difference value calculation unit 42 obtains the operation amounts of the left spool valve SL and the right spool valve SR detected by the left operation amount detection unit 34 and the right operation amount detection unit 35, and calculates the difference between the operation amounts (S04, S05).

[0050] Next, it is determined whether the traveling two-speed mode is set (S06). If the traveling two-speed mode is set (S06: YES), the turning determination unit 43 determines whether the calculated difference value is equal to or greater than the high-speed gear determination value, i.e., 25% or greater of the maximum value of the operation command value or spool operation amount (S07). If it is 25% or greater (S07: YES), it is determined that a turning operation has been performed, the traveling two-speed mode is turned OFF (S08), and the traveling temporary one-speed mode (S09) is turned ON. If the difference value is smaller than 25% of the maximum value (S07: NO), no particular processing is performed, and the processing is repeated from the beginning.

[0051] If the mode is not set to the two-speed traveling mode (S06: NO), it is determined whether the mode is set to the temporary one-speed traveling mode (S10). If the mode is set to the temporary one-speed traveling mode (S10: YES), the turning determination unit 43 determines whether the calculated difference value is equal to or less than the low-speed stage determination value, that is, equal to or less than 15% of the maximum value of the operation command value or the spool operation amount (S11). If it is equal to or less than 15% (S11: YES), it is determined that a turning operation is not being performed, the temporary one-speed traveling mode is turned OFF (S12), and the traveling mode selected by the operator at that time (the two-speed traveling mode if no particular operation is being performed) is turned ON (S13). If the difference value is greater than 15% of the maximum value, no particular processing is performed, and the processing is repeated from the beginning. Also, if the second-speed travel mode is not set (S06: NO) and the temporary first-speed travel mode is not set (S10: NO), no particular process is performed and the process is repeated from the beginning.

[0052] <Operation while driving> Based on the above explanation, the operation of the crawler crane 1 equipped with the travel control device 50 and travel control system 60 during travel will be described. In the following explanation, it is assumed that the crawler crane 1 is initially set to single-speed travel mode, and that the operator operates it using the remote controller 20. If the crawler crane 1 is operated using the operation unit 10, it is sufficient to operate the lever to an extent that is equal to the ratio of the input value to the maximum value of the operation command value, in which case the travel control device 50 will operate.

[0053] When the crawler crane 1 starts traveling, it travels in first speed. Then, when the operator operates the setting switch 26 to set the traveling second speed mode, the solenoid of the speed change control valve 32 is energized, the traveling speed of the hydraulic motor M is switched to second speed, and the traveling speed of the crawler crane 1 increases. In this case, when operating the remote controller 20, for example, to move forward at maximum speed, the operator tilts the right stick 25 and the left stick 24 forward to the maximum extent, so the operation command values ​​are left stick (X: 0, Y +255) and right stick (X: 0, Y 255). Therefore, the difference between the left and right operation command values ​​is 20% or less of the maximum value, and no speed change is performed.

[0054] From this state, when attempting to make a gentle turn to the left, suppose that the tilt of the left stick 24 is eased until the operation command value becomes left stick (X: 0, Y: 200) right stick (X: 0, Y: 255). When the hydraulic motor is rotated based on such an operation command value, if the crawler 2 is rotated while the travel stage is in second gear, the hydraulic motor M cannot generate enough driving torque to cause the crawler 2 to slide left or right and turn, and the crawler crane 1 continues to move straight. In this embodiment, when the difference value exceeds 20% of the maximum value of the operation command value, that is, when a difference of 51 or more occurs between the input values ​​of the left stick 24 and the right stick 25, the two-speed traveling mode is turned OFF (S08) and the temporary one-speed traveling mode is turned ON (S09). Note that when operation is performed using the operation unit 10, the judgment is made based on 20% of the maximum drive amount of the left spool valve SL and the right spool valve SR. At this time, the solenoid of the speed change control valve 32 is de-energized, and the hydraulic motor M is switched to first gear. As a result, the drive torque is increased to the extent that the crawler 2 can slide left and right, and the crawler crane 1 swings gently to the left.

[0055] After swinging to the desired direction, if the operator tilts the left stick 24 to the maximum again to move the crawler crane 1 straight, the command value becomes the left stick (X: 0, Y: 255) and the right stick (X: 0, Y: 255). Then, the difference value becomes 20% or less of the maximum value, so the temporary first-speed traveling mode is turned OFF (S12) and the selected traveling mode is turned ON (S13), and the mode returns to the two-speed traveling mode. At this time, the power supply to the solenoid of the speed change control valve 32 is resumed, and the traveling stage of the hydraulic motor M is switched to second speed. Therefore, when the swing operation is completed, the crawler crane 1 moves straight at the speed of the second-speed traveling stage.

[0056] <Effects> The travel control device 50 of the present invention makes it possible to rotate the crawler crane 1 simply by operating a lever or stick that has traditionally been used for travel operations, thereby reducing the burden on the worker during travel operations. In particular, since the crawler crane 1 does not have a driver's seat and both travel operations and gear shift operations must be performed by hand, application of the present invention not only greatly improves operability while traveling, but also improves safety while traveling because it is no longer necessary to take your hands off the travel lever.

[0057] The travel speed switching control device according to the present invention can reduce manufacturing and maintenance costs compared to a configuration that includes an automatic single-speed valve in the fluid circuit. This is because, while including an automatic single-speed valve requires designing a dedicated fluid circuit and setting and adjusting the pilot pressure for automatic shifting, the travel speed control device according to the present invention only needs to control the pilot pressure for switching the position of the motor displacement switching valve, and the shift control valve 32 used for this control can also be provided separately from the drive circuit for the hydraulic motor M.

[0058] Unlike the conventional automatic single-speed valve that judges turning based on the difference in pilot pressure, the travel speed control device according to the present invention makes it easy to adjust the threshold value for automatic gear shifting because the control unit judges turning. Therefore, it can be easily applied between models with different aircraft weights and pump P discharge pressures, and adjustments for each aircraft are also easy.

[0059] The present invention can prevent industrial machinery from stopping due to insufficient drive torque of the crawler while it is running. In addition, since the fact that the machine stops due to insufficient torque can be confirmed as a running characteristic at the time of design and has a high reproducibility, the fact that the operator performs an operation with the intention of turning while actually running is suitable as a condition for automatic gear shifting. Therefore, by applying the present invention, it is possible to rotate the crawler crane 1 without stopping it during a rotation operation, even without an automatic speed change valve or a sensor for measuring the driving pressure of the hydraulic motor, and because automatic speed change is possible with a simple structure, it can be manufactured more cheaply than conventional automatic speed change mechanisms.

[0060] The cruise control device 50 and cruise control system 60 according to the present invention change the threshold value used for turning judgment according to the immediately preceding driving mode. Therefore, even if the input value fluctuates due to vibration or the like while the operator is turning near the threshold value, chattering is unlikely to occur when changing the driving stage, improving operability.

[0061] The cruise control device 50 and cruise control system 60 according to the present invention are controlled by the controller 40, and therefore both can be mounted on industrial machinery without a significant increase in manufacturing costs.

[0062] <Modification> In the embodiment, the difference value used for turning judgment was set to 20% of the maximum value, but in the application of the present invention, it does not necessarily have to be set to 20%, and can be adjusted within the range of 15% to 25% depending on the type and size of the industrial machine to which the present invention is applied.

[0063] In the embodiment, when driving operation is performed using the left lever 11 and the right lever 12, the operation amounts of the left spool valve SL and the right spool valve SR are detected, but in the application of the present invention, it is not necessarily necessary to detect the operation amounts of the spool valves. For example, the operation amounts of the left lever 11 and the right lever 12 may be detected and used to calculate the difference value. Furthermore, even when the remote control unit 22 of the remote controller 20 is used to perform the traveling operation, the difference value may be calculated using the movement amount of the spool instead of calculating the difference value based on the operation command value.

[0064] In the embodiment, the travel mode of the crawler crane 1 is selected arbitrarily by the operator, and when the temporary single-speed travel mode is turned OFF, the crawler crane is configured to return to the travel mode selected by the operator, but this configuration does not necessarily have to be adopted in implementing the present invention. For example, a configuration may be adopted in which, after a turn, the first speed mode is temporarily maintained for several seconds after it is determined that the vehicle is not turning, thereby facilitating fine adjustment of the turning angle.

[0065] In the embodiment, the threshold value used for determining whether or not a vehicle is turning is set to a high gear ratio determination value and a low gear ratio determination value. However, in the application of the present invention, it is not always necessary to change the threshold value depending on the immediately preceding driving mode. For example, if the difference value is 20% or more of the operation command value or the maximum value of the spool operation amount, it may be determined that a turning operation is being performed, and if the difference value is less than 20%, it may be determined that a turning operation is not being performed. In this way, even if the threshold value is fixed, there is no effect when either the lever or the stick is tilted to its maximum angle and operation is easy because the threshold value is a fixed value.

[0066] In the embodiment, a crawler crane in which the hydraulic motor M has two travel stages is described, but the application of the present invention is not limited to hydraulic motors with two travel stages. For example, even if the travel stages are set to three or more stages or are set to be continuously variable, the hydraulic motor can be controlled to switch to the swing mode when it is determined that a swing operation is being performed.

[0067] In the means for solving the problem, the third invention is structured to cite only the first invention, but this does not prevent the third invention from citing the description of the second invention, and in implementing the present invention, the third invention may have the structure described in the second invention. [Explanation of symbols]

[0068] Crawler crane...1, left crawler...2L, travel control device...3, travel control system...4, right crawler...2R, 10...operation unit, 11...left lever, 12...right lever, 20...remote control device, 22...remote control unit, 24...left stick, 25...right stick, 26...setting switch, 31...switching valve, 32...speed change control valve, 33...speed change mechanism, 34...left operation amount detection unit, 35...right operation amount detection unit, 42...difference value calculation unit, 43...turn determination unit, 44...control unit, SL...left spool valve, SR...right spool valve, M...hydraulic motor, C...control valve, LP1...first gear position, LP2...first gear command position, HP1...second gear position, HP2...second gear command position

Claims

1. A travel control device for an industrial machine having crawlers on each of the left and right sides of a machine body, each of the crawlers being driven by a fluid pressure motor having a speed change mechanism, An operation unit for operating the left and right crawlers; a rotation determination unit that determines whether a rotation operation has been performed on the operation unit; A control unit that performs control to switch the travel stage of the fluid pressure motor based on the determination of the turning determination unit, The fluid pressure motor can set a travel speed to at least two speeds, a low speed and a high speed, The control unit sets the travel stage of the fluid pressure motor to the low speed stage while the turning determination unit determines that a turning operation is being performed.

2. The control unit is configured to set the driving mode to a low-speed mode or a high-speed mode by an operation of an operator, 2. The driving control device according to claim 1, wherein the transmission mechanism is set to a low gear in the low gear mode, and the transmission mechanism is set to the high gear in the high gear mode, and while the turning determination unit determines that a turning operation is being performed in the high gear mode, the driving gear is set to the low gear as a temporary low speed mode, and when the turning determination unit determines that a turning operation is not being performed in the temporary low speed mode, the driving mode is set to the driving mode selected by an operator.

3. The industrial machine includes a control valve for adjusting a direction and a flow rate of the working fluid supplied to the hydraulic motor, The control valve includes a left spool valve connected to the fluid pressure motor corresponding to the left crawler, and a right spool valve connected to the fluid pressure motor corresponding to the right crawler, The left spool valve is provided with a left operation amount detection unit that detects an operation amount of the spool, The right spool valve is provided with a right operation amount detection unit that detects an operation amount of the spool, 2. The driving control device according to claim 1, wherein the turning determination unit determines that a turning operation is being performed when a predetermined difference occurs between a detection value of the left operation amount detection unit and a detection value of the right operation amount detection unit.

4. 4. The travel control device according to claim 3, wherein the predetermined difference is a predetermined value that is equal to or greater than 15% and equal to or less than 25% of a maximum drive amount of the right spool valve and the left spool valve.

5. the predetermined difference is set to a high speed gear determination value when the fluid pressure motor is set to a high speed gear, and is set to a low speed gear determination value when the fluid pressure motor is set to a low speed gear, 5. The cruise control device according to claim 4, wherein the high gear ratio determination value is set to a value greater than the low gear ratio determination value.

6. a drive flow passage for supplying pressure oil to the fluid pressure motor and a speed change flow passage for operating the speed change mechanism are connected to the fluid pressure motor; The transmission mechanism changes the travel stage according to a working fluid pressure, the speed change flow passage includes a switching valve which is a pilot valve that controls an operation of the speed change mechanism, and a speed change control valve which is a solenoid valve that controls the operation of the switching valve, The switching valve is switchable between a high speed position for setting the travel stage to a high speed stage and a low speed position for setting the travel stage to a low speed stage, the speed change control valve is switchable between a high speed command position for connecting a pilot port of the switching valve to a pump and a low speed command position for connecting the pilot port to a hydraulic fluid tank, 6. The cruise control device according to claim 1, wherein the control unit sets the shift control valve to a low speed command position while the turning determination unit determines that a turning operation is being performed.

7. An industrial machine having crawlers on each of the left and right sides of a machine body, each of the crawlers being driven by a fluid pressure motor having a speed change mechanism; A travel control system including a remote control device having an operation unit for inputting an operation command value for the crawler, a rotation determination unit that determines whether a rotation operation has been performed based on an operation command value transmitted from the remote controller; A control unit that controls switching of the travel stage of the fluid pressure motor based on the determination of the turning determination unit, The fluid pressure motor can set a travel speed to at least two speeds, a low speed and a high speed, The control unit sets the crawler travel stage to the low speed stage while the turning determination unit determines that a turning operation is being performed.

8. The control unit is characterized in that the driving mode is set to a low-speed mode or a high-speed mode by operation by an operator, the control unit sets the transmission mechanism to the low-speed mode in the low-speed mode, and sets the transmission mechanism to the high-speed mode in the high-speed mode, and while the turning determination unit determines that a turning operation is being performed in the high-speed mode, sets the driving stage to the low-speed mode as a temporary low-speed mode, and when the turning determination unit determines that a turning operation is not being performed in the temporary low-speed mode, sets the driving stage to the driving mode selected by the operator.

9. 8. The travel control system according to claim 7, wherein the turning determination unit determines that a turning operation is being performed when a predetermined difference occurs between an operation command value for the fluid pressure motor corresponding to the left crawler and an operation command value for the fluid pressure motor corresponding to the right crawler, both input to the remote controller.

10. 10. The cruise control system according to claim 9, wherein the predetermined difference is a predetermined value that is 15% to 25% of the maximum value of the operation command value.

11. the predetermined difference is set to a high speed gear determination value when the fluid pressure motor is set to a high speed gear, and is set to a low speed gear determination value when the fluid pressure motor is set to a low speed gear, The cruise control system according to claim 10, wherein the high gear ratio determination value is set to a value greater than the low gear ratio determination value.

12. a drive flow passage that supplies pressure oil to the fluid pressure motor and a speed change flow passage that operates the speed change mechanism are connected to the fluid pressure motor; The transmission mechanism changes the travel stage according to a working fluid pressure, the speed change flow passage includes a switching valve which is a pilot valve that controls an operation of the speed change mechanism, and a speed change control valve which is a solenoid valve that controls the operation of the switching valve, The switching valve is switchable between a high speed position for setting the travel stage to a high speed stage and a low speed position for setting the travel stage to a low speed stage, the speed change control valve is provided with a speed change control valve that is switchable between a high speed command position that connects a pilot port of the switching valve to a pump and a low speed command position that connects the pilot port to a hydraulic fluid tank, 12. The cruise control system according to claim 7, wherein the control unit sets the shift control valve to a low speed command position while the turning determination unit determines that a turning operation is being performed.

Images