JP2008207721A - Traveling control device of construction machinery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an operator's load by allowing a driver to shift the traveling speed of a vehicle by, for example, both a switch at this side and a switch in a switch box. <P>SOLUTION: When a shift switch 15 installed in the switch box 13 in a cab 5 is shifted to a low speed side, a shift operation by an additional shift switch 23 at this side of the operator is made to take preference to that of the speed-shift switch 15. When the shift switch 15 is shifted from the low speed side to a high speed side, the shift operation of the speed-shift switch 15 is made to take preference to that of the additional shift switch 23. Thereby, when ground grading is carried out, for example, by an earth-moving machine, the speed shift switch 15 is shifted to the low speed side, and the additional shift switch 23 at this side is made to take preference to that of the speed shift switch 15, so that the operator can simply shift the traveling speed to the high speed or low speed by the switch at this side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a traveling control device for a construction machine that is preferably used for traveling control of a construction machine such as a hydraulic excavator or a hydraulic crane.

  In general, a construction machine such as a hydraulic excavator is provided with a switch box in the vicinity of a driver's seat together with an operation lever and the like. For example, the traveling speed of the vehicle is selectively set at two positions, a high speed side and a low speed side. A plurality of operation switches including a speed changeover switch such as a travel mode selection switch for switching to is attached (for example, see Patent Document 1).

  Further, on the front side of the driver's seat, a speed increasing / decreasing means such as a traveling lever that is manually tilted forward and backward by an operator or a traveling pedal that performs a stepping operation is provided. The vehicle traveling speed is increased or decreased according to the operation or the depression operation.

  In this type of conventional technology, the operator of the construction machine is operating the travel lever or pedal while sitting in the driver's seat, and the speed change switch is appropriately operated with a fingertip or the like, thereby reducing the vehicle torque. The vehicle is driven at a high speed or at a low speed with a high torque.

  On the other hand, as another prior art, a push button-type hand switch is provided in a grip portion of the travel lever, etc., and an operator who manually operates the travel lever presses the hand switch with a fingertip or the like. Is configured to run at a high speed with a low torque or at a low speed with a high torque (see, for example, Patent Document 2).

JP 2000-303499 A JP 2000-71801 A

  By the way, in the prior art according to Patent Document 1 described above, for example, the speed change switch is arranged on the upper surface side of the switch box provided on the right side of the driver's seat. This can prevent the occurrence of erroneous operations such as accidentally touching the speed changeover switch with the fingertip of the vehicle, and the operation of manually switching the vehicle running speed between the high speed side and the low speed side can be performed stably and safely. is there.

  However, since the speed change switch in this case is arranged at a position separated from the travel lever, the operator who tilts the travel lever frequently switches the travel speed between high speed and low speed. In this case, the operator needs to release his hand from the travel lever each time, so that not only the operability is lowered but also the burden on the operator is increased.

  On the other hand, in the case of the prior art disclosed in Patent Document 2, the traveling speed can be appropriately switched between high speed and low speed by operating a push button type hand switch provided on the grip portion of the traveling lever with a fingertip. There is an advantage that the speed switching operation can be easily performed by the operator without releasing the hand from the traveling lever.

  However, in this case, there is a possibility that the operator who tilts the travel lever may mistakenly operate the hand switch with a fingertip or the like, and the traveling speed suddenly increases from low to high, contrary to the operator's intention, or When switching from low speed to high speed, there is a problem that it is difficult to ensure safety in traveling operation.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to perform an operation for switching the traveling speed of a vehicle, for example, on both the operator's hand side and the switch box side. It is an object of the present invention to provide a traveling control device for a construction machine that can reduce the burden by improving the operability of the construction machine and can improve the safety in traveling operation.

  In order to solve the above-described problems, the present invention provides a self-propelled vehicle body provided with a driver's seat, and is provided near the driver's seat to switch the traveling speed between a high speed side and a low speed side. A switch box provided with a speed change switch, a speed increasing / decreasing means which is provided in the vehicle body and is located on the front side of the driver's seat to increase / decrease a traveling speed according to an operator's manual operation or stepping operation, and a speed change switch of the switch box And a control means for variably controlling the travel speed of the vehicle body in accordance with the signal from the speed increasing / decreasing means.

  The feature of the configuration adopted by the invention of claim 1 is that the speed increasing / decreasing means is provided with an additional changeover switch for switching the traveling speed between the low speed side and the high speed side separately from the speed change switch of the switch box, The control means gives priority to speed change operation by the additional changeover switch over the speed changeover switch when the speed changeover switch is changed to the low speed side, and the speed changeover switch is switched to the high speed side. In some cases, the speed change operation by the speed change switch is given priority over the additional change switch.

  According to a second aspect of the invention, there is provided a first notification means for notifying that the switching operation by the additional switching switch is invalid when the speed switching switch is switched to the high speed side.

  According to a third aspect of the present invention, there is provided a second notifying means for notifying that the switching operation by the additional changeover switch is effective when the speed changeover switch is switched to the low speed side.

  As described above, according to the first aspect of the present invention, when the speed change switch provided in the switch box is switched to the low speed side, the speed change by the additional change switch on the speed increasing / decreasing means side than the speed change switch. Prioritizing the switching operation, when the speed change switch is switched to the high speed side, the speed change operation by the speed change switch is given priority over the additional change switch. When the operation is performed, the traveling speed of the vehicle can be switched to high speed with low torque or switched to low speed with high torque by simply operating the speed selector switch on the switch box side.

  For example, when the operator frequently switches the traveling speed between a high speed and a low speed in order to perform leveling work using a soil removal device, the speed change switch should be switched to the low speed side in advance. Thus, priority can be given to the speed switching operation by the additional switching switch on the speed increasing / decreasing means side rather than the speed switching switch. As a result, for example, the operator can open and close the additional change-over switch without releasing his / her hand from the travel lever (speed increase / decrease means), thereby enabling frequent switching of the travel speed between high speed and low speed. It can be done easily.

  Accordingly, an operation for switching the traveling speed of the vehicle can be performed, for example, on both the operator's hand side (additional changeover switch) and the speed change switch on the switch box side, and the operator's operability can be improved and the burden can be reduced. Thus, the safety in traveling operation can be further improved.

  According to the second aspect of the present invention, when the speed selector switch on the switch box side is switched to the high speed side, for example, the switching operation by the additional selector switch which is a hand switch is invalidated. By notifying with a notification means (for example, a lamp such as a light emitting element, a buzzer, or a voice synthesizer), the operator can immediately be notified that the operation by the additional changeover switch is invalid, and the switching operation of the traveling speed can be performed. The switch on the switch box side can be urged to do so.

  Furthermore, according to the invention described in claim 3, when the speed selector switch on the switch box side is switched to the low speed side, for example, the switching operation by the additional selector switch which is a hand switch can be made effective. Is notified by the second notification means (for example, a lamp such as another light emitting element, a buzzer or a voice synthesizer), so that the operator can immediately be notified that the operation by the additional changeover switch is effective. The operator can change the traveling speed from a low speed to a high speed or from a high speed to a low speed, for example, with a fingertip or the like using an additional changeover switch on the hand side.

  Hereinafter, a case where the traveling control device for a construction machine according to an embodiment of the present invention is applied to a small hydraulic excavator called a so-called mini excavator will be described in detail with reference to the accompanying drawings.

  Here, FIG. 1 to FIG. 8 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a small hydraulic excavator as a construction machine. The hydraulic excavator 1 is mounted on a self-propelled lower traveling body 2 and is pivotable on the lower traveling body 2. The upper rotating body 3 constituting the vehicle body of the excavator 1, and a front device 7 and a soil removal device 8 described later are roughly configured.

  Reference numeral 4 denotes a revolving frame that constitutes a base frame of the upper revolving structure 3, and the revolving frame 4 is configured as a sturdy support structure formed by welding a plurality of steel plates or the like. A cab 5 is provided on the front side of the revolving frame 4, and a counterweight 6 is provided on the rear side of the cab 5. The cab 5 is closed on the lower surface side by a floor plate 5A as shown in FIGS. 2 and 3, and defines a cab inside thereof.

  Reference numeral 7 denotes a front device provided on the front side of the revolving frame 4. As the front device 7, for example, a swing type working device including a swing post 7 </ b> A that swings leftward and rightward is adopted. And the front apparatus 7 performs excavation work, such as earth and sand, using the bucket 7B etc. of the front end side, for example.

  8 is a soil removal device provided on the front side of the lower traveling body 2, and the soil removal device 8 is lifted up and down by an elevating cylinder (not shown) or the like, and usually separated upward from the ground (road surface). It is arranged at the position. The earth removal device 8 is lowered to a position where it is placed on the ground as shown in FIG. 1 when performing leveling work, for example.

  Reference numeral 9 denotes a driver's seat provided on the floor plate 5A of the cab 5. The driver's seat 9 is disposed in the cab 5 as shown in FIGS. 2 and 3 and is seated by an operator. Console devices 10, 11 and the like which will be described later are provided on the left and right sides of the driver's seat 9, and a driving lever / pedal device which will be described later for increasing / decreasing the traveling speed of the vehicle according to the operation of the operator. 20 etc. are provided.

  Reference numeral 10 denotes a left console device provided on the left side of the driver's seat 9, and the left console device 10 has a console box 10A. The front side of the console box 10A includes, for example, front and rear directions and left and right directions. The left operating lever 10B is provided to be tilted.

  11 is a right console device provided on the right side of the driver's seat 9, and the right console device 11 includes a console box 11A, an operation lever 11B, and the like, similarly to the left console device 10 described later. The right operation lever 11B is for operating, for example, the front device 7 and the like when the operator tilts with both hands together with the left operation lever 10B.

  Reference numeral 12 denotes a blade lever provided on the right side (back side) of the right console device 11, and the blade lever 12 tilts forward and backward when the operator sitting in the driver's seat 9 grips it with, for example, the right hand. Thus, the earth removing device 8 in FIG. 1 is moved up and down.

  A switch box 13 is provided on the right console device 11 at the rear side of the console box 11A. On the upper surface of the switch box 13, a light switch 14, a speed change switch 15, a wiper switch as shown in FIG. 16, an auxiliary hydraulic flow rate changeover switch 17, an operation system changeover switch 18, an air conditioner operation panel 19 and the like are attached.

  The light switch 14, the speed change switch 15, the wiper switch 16, the auxiliary hydraulic flow rate change switch 17 and the operation system change switch 18 include lamps 14A, 15A, 16A, 17A, 18A made of light emitting elements such as light emitting diodes. As shown by a dotted line in FIG. 4, it is attached to the lower surface side. These lamps 14A, 15A, 16A, 17A, and 18A are lit with different colors or marks in order to give distinguishability to the respective switch operations.

  Here, the light switch 14 is a switch for turning on or off an illumination lamp (not shown) such as a headlamp. The speed changeover switch 15 is a switch for selectively changing the traveling speed of the vehicle between the high speed side and the low speed side, and the capacity variable portion 26A of the hydraulic motor 26 is switched between a small capacity and a large capacity as will be described later. It has a function to switch between.

  The wiper switch 16 is a switch for operating a wiper (not shown) on the front glass side of the cab 5, for example, when it rains. The auxiliary hydraulic flow rate switching switch 17 assists the flow of pressure oil. Configures a switch to be switched. That is, for example, when a work tool (not shown) with an actuator such as a grapple or breaker is attached to the front end side of the front device 7 in place of the bucket 7B, the flow rate of the pressure oil to be supplied to these work tools is the auxiliary hydraulic flow rate. It is switched by a switching operation of the changeover switch 17. The operation system switching switch 18 is a switch that switches, for example, an operation system switching valve (not shown) between a work operation position and a soil removal operation position.

  On the other hand, a lamp 15A (hereinafter referred to as an invalid lamp 15A) attached to the speed change switch 15 constitutes a first notification means that is turned on when the speed change switch 15 is switched to the high speed side. The fact that the speed switching operation by the changeover switch 23 is invalid is notified by lighting the lamp. The color or mark when the invalid lamp 15A is lit is selected as a color or mark different from the other lamps 14A, 16A, 17A, 18A.

  A traveling lever / pedal device 20 is provided on the floor 5A of the cab 5 and located on the front side of the driver's seat 9. The traveling lever / pedal device 20 is used for left and right traveling which constitutes a speed increasing / decreasing means. Lever 21A, 21B and left and right traveling pedals 22A, 22B are provided. Then, the operator sitting in the driver's seat 9 manually tilts the traveling levers 21A and 21B or depresses the traveling pedals 22A and 22B, thereby depending on the operation amount of the vehicle (hydraulic pressure). The traveling speed of the excavator 1) is increased or decreased as described later.

  In this case, the operation amount of the travel levers 21A and 21B or the travel pedals 22A and 22B is detected by an operation amount detector 33 (see FIG. 7) described later, and the detection signal is output to the controller 32. The controller 32 controls the direction control valve 31 as will be described later in accordance with the detection signal at this time.

  Further, the left and right traveling levers 21A and 21B are operated, for example, by steering the vehicle by appropriately changing the amount of tilting operation by the operator. This is also true when the left and right traveling pedals 22A and 22B are stepped on at different angles.

  Reference numeral 23 denotes an additional changeover switch provided in addition to the travel lever / pedal device 20. The additional changeover switch 23 is attached to the upper end side (grip portion) of the travel lever 21B as shown in FIG. The operator holding the lever 21B constitutes a hand switch that is opened and closed with a fingertip.

  Here, the additional changeover switch 23 is closed when the operator performs a pressing operation with a fingertip or the like, and at this time, a signal for switching the traveling speed to the high speed side is output to the controller 32 described later. When the operator releases the pressing operation, the additional changeover switch 23 is automatically opened, and a signal for switching the traveling speed to the low speed side is output to the controller 32.

  Further, a priority lamp 23A is provided on the upper end side (grip portion) of the traveling lever 21B in addition to the additional changeover switch 23, and the priority lamp 23A is constituted by a light emitting element such as a light emitting diode. The priority lamp 23A constitutes second informing means that lights up when the speed selector switch 15 on the switch box 13 side is switched to the low speed side. For example, the speed change operation by the additional selector switch 23 is effective. In other words, the lamp is turned on to give priority to the operation of the additional changeover switch 23 over the operation of the speed changeover switch 15.

  Next, 24 is a hydraulic pump that constitutes a hydraulic power source together with the tank 25 shown in FIG. 7, and this hydraulic pump 24 is rotationally driven by a prime mover (not shown) provided on the upper swing body 3 of the hydraulic excavator 1, Pressure oil is supplied to a hydraulic motor 26 and the like which will be described later.

  Reference numeral 26 denotes a left and right traveling hydraulic motor (only one is shown in FIG. 7) provided in the lower traveling body 2, and the hydraulic motor 26 has a variable capacity portion 26A as shown in FIG. It is constituted by a capacity type hydraulic motor, and is connected to the hydraulic pump 24 and the tank 25 via a pair of main pipelines 27A and 27B. The hydraulic motor 26 is rotationally driven by supplying and discharging pressure oil from the hydraulic pump 24, and the traveling speed of the vehicle is increased or decreased according to the rotational speed of the hydraulic motor 26.

  Reference numeral 28 denotes a tilt actuator as a capacity variable mechanism attached to the hydraulic motor 26. The tilt actuator 28 tilts the capacity variable portion 26A of the hydraulic motor 26 between a large capacity position and a small capacity position. As a result, the rotational speed of the hydraulic motor 26 is increased or decreased according to the flow rate of the pressure oil based on the speed characteristic of one of the characteristic lines 29 and 30 as illustrated in FIG.

  That is, the tilting actuator 28 tilts and drives the displacement variable portion 26A of the hydraulic motor 26 to either the large capacity position or the small capacity position in accordance with a control signal from the controller 32 described later. When the variable capacity section 26A is switched to the large capacity position, the hydraulic motor 26 is rotated at a low speed with a large torque along the characteristic line 29, and when the variable capacity section 26A is switched to the small capacity position, the characteristic line 30 is reached. Along with this, it is rotated at a high speed with a low torque.

  A directional control valve 31 is provided between the hydraulic pump 24, the tank 25 and the hydraulic motor 26 and is provided in the middle of the main pipelines 27A and 27B. The directional control valve 31 is, for example, a control signal from the controller 32 or The flow rate of the pressure oil that is switched and controlled by a pilot signal or the like and supplied to or discharged from the hydraulic pump 24 to the hydraulic motor 26 is increased or decreased according to the operation amount on the traveling lever / pedal device 20 side.

  Reference numeral 32 denotes a controller as a control means composed of a microcomputer or the like. The controller 32 is connected at its input side to the speed change switch 15, the additional changeover switch 23 and an operation amount detector 33 described later, and its output side is an invalid lamp. 15A, the priority lamp 23A, the tilting actuator 28, the direction control valve 31 and the like.

  The controller 32 has a storage unit 32A composed of a ROM, a RAM, and the like, and a processing program shown in FIG. 8 to be described later is stored in the storage unit 32A. Then, the controller 32 performs vehicle travel control processing according to the processing program of FIG. 8, that is, performs control to turn on or off the invalid lamp 15A and the priority lamp 23A, and control to switch the vehicle travel speed between low speed and high speed. Is what you do.

  33 is an operation amount detector that detects the operation amount of the travel lever / pedal device 20, and this operation amount detector 33 is used for an operator sitting in the driver's seat 9 in the cab 5 to travel or stop the vehicle. The amount of operation when the levers 21A, 21B are tilted (the pedals 22A, 22B are depressed) and the detection signal is output to the controller 32, so that the vehicle traveling speed is determined according to the detection signal. The number is increased or decreased as described later.

  The hydraulic excavator 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described next.

  First, the operator opens the door of the cab 5, gets on the floor board 5 </ b> A, and sits on the driver's seat 9. At this time, since there is no obstacle or the like on the front side of the driver's seat 9 on the floor board 5A, the operator can get in smoothly and can obtain a wide forward view.

  Then, when the operator seated in the driver's seat 9 activates the prime mover to rotationally drive the hydraulic pump 24 and operates the traveling lever / pedal device 20 in this state, the direction control is performed with a stroke corresponding to the operation amount at this time. The valve 31 is switched from the neutral position. For this reason, the hydraulic motor 26 on the lower traveling body 2 side is supplied with hydraulic oil at a flow rate corresponding to the stroke of the direction control valve 31 from the hydraulic pump 24, and the vehicle (hydraulic excavator 1) It is possible to travel on the road at a traveling speed substantially proportional to

  Therefore, the vehicle running control process by the controller 32 will be described according to the processing program of FIG.

  First, when the processing operation starts, in step 1, an operation signal is read from the speed change switch 15 on the switch box 13 side, and an operation signal is also read from the additional change-over switch 23 on the traveling lever 21B side.

  Then, in the next step 2, it is determined whether or not the speed changeover switch 15 is switched to the low speed side, and when it is determined “YES”, the process proceeds to step 3 to turn on the priority lamp 23A. At this time, the invalid lamp 15A on the switch box 13 side is turned off.

  That is, in the process of step 3, the priority lamp 23A is turned on when the speed selector switch 15 on the switch box 13 side is switched to the low speed side, and the switching operation of the additional selector switch 23 at the operator's hand is effective. The lamp is turned on to give priority to the operation of the additional changeover switch 23 over the operation of the speed changeover switch 15.

  In the next step 4, it is determined whether or not the operator is pressing the additional changeover switch 23 at hand with a fingertip or the like to perform a closing operation. Here, while it is determined as “NO” in Step 4, the additional changeover switch 23 is in the open state, and the operator has selected to travel at low speed, so the process proceeds to Step 5 to select the low speed characteristic. Then, control is performed to keep the traveling speed of the vehicle at a low speed.

  That is, in the process of step 5, a signal for switching the traveling speed to the low speed side is output to the controller 32 by opening the additional changeover switch 23, and the tilting actuator 28 controls the capacity variable portion 26A by the control signal from the controller 32. Since the position is switched to the large capacity position, the traveling hydraulic motor 26 is rotated at a low speed with a large torque along the characteristic line 29 in FIG. 6 to keep the traveling speed of the vehicle at a low speed characteristic.

  If “YES” is determined in Step 4, the operator presses the additional changeover switch 23 at hand with the fingertip or the like to perform the closing operation. In this case, the process proceeds to Step 9 and high speed characteristics are obtained as described later. Then, control is performed to switch the traveling speed of the vehicle to a high speed, and then the process proceeds to step 6 and returns.

  On the other hand, if “NO” is determined in step 2, the speed change switch 15 on the switch box 13 side has been switched from the low speed side to the high speed side, so that the process proceeds to the next step 7 and the invalid lamp on the switch box 13 side. 15A is turned on, and the priority lamp 23A on the traveling lever 21B side is turned off.

  That is, in the process of step 7, by turning on the invalid lamp 15A on the switch box 13 side, the switching operation of the additional selector switch 23 on the traveling lever 21B side is invalid, and the operation of the speed selector switch 15 is changed to the additional selector switch. It is notified by lamp lighting that priority is given to 23.

  In the next step 8, it is determined whether or not the additional changeover switch 23, which is the operator's hand switch, is opened, and regardless of the operation of the additional changeover switch 23, that is, “YES” or “NO”. Regardless of which, the control proceeds to the next step 9 to select the high speed characteristic. Note that the determination process in step 8 is not always necessary and may be omitted.

  Next, in step 9, the controller 32 drives the tilting actuator 28 in accordance with a signal for switching the traveling speed output from the speed changeover switch 15 to the high speed side, and moves the displacement variable portion 26A of the hydraulic motor 26 to the large displacement position. To the small capacity position. Then, the traveling hydraulic motor 26 is rotated at a high speed with a low torque along the characteristic line 30 in FIG. 6 when the capacity variable portion 26A is switched to the small capacity position, and the traveling speed of the vehicle is controlled with the high speed characteristics. Thereafter, the process returns at step 6.

  Thus, according to the present embodiment, when the speed change switch 15 provided in the switch box 13 in the cab 5 is switched to the low speed side, the additional changeover switch 23 located closer to the operator than the speed change switch 15 is provided. The switching operation is prioritized, and when the speed switching switch 15 is switched from the low speed side to the high speed side, the switching operation of the speed switching switch 15 is given priority over the additional switching switch 23.

  As a result, the operator sitting in the driver's seat 9 in the cab 5 operates the speed change switch 15 on the switch box 13 side, for example, when performing a normal travel operation at a construction site or the like, and thereby increases the travel speed of the vehicle. It can be switched to high speed with low torque, or to low speed with high torque.

  For example, when the operator frequently switches the traveling speed between a high speed and a low speed in order to perform leveling work using the earth removal device 8, the speed changeover switch 15 is previously switched to the low speed side. Thus, priority can be given to the speed switching operation by the additional switching switch 23 on the hand side rather than the speed switching switch 15. Thus, for example, the operator can easily open and close the additional changeover switch 23 with a fingertip or the like without releasing his hands from the traveling levers 21A, 21B, etc., and the traveling speed of the vehicle is frequently increased between high speed and low speed. The operation of switching to can be easily performed.

  That is, in the leveling work using the earth removal device 8, the excavator 1 (vehicle) is slowly advanced at a low speed while the earth removal device 8 is placed on the ground as shown in FIG. Can be accurately leveled, and when returning to the rear appropriately, the leveling operation can be efficiently performed in a short time by moving the vehicle backward at a high speed.

  Further, when the speed selector switch 15 on the switch box 13 side is switched to the high speed side, the invalid lamp 15A notifies that the switching operation by the additional selector switch 23 which is a hand switch is invalidated. As a result, the operator can be immediately notified that the operation by the additional changeover switch 23 is invalid, and the speed changeover switch 15 on the switch box 13 side can be prompted to perform the operation of changing the running speed.

  Further, when the speed selector switch 15 on the switch box 13 side is switched to the low speed side, the operator is notified by the priority lamp 23A on the hand side that priority is given to the switching operation by the additional switch 23 on the hand side. Thus, the operator can immediately be notified that the operation by the additional changeover switch 23 is effective, and the operator can change the traveling speed from the low speed to the high speed, or from the high speed to the low speed. It can be used for quick switching operation with a fingertip or the like.

  Therefore, according to the present embodiment, the operation of switching the traveling speed of the vehicle can be performed by both the additional changeover switch 23 on the operator's hand side and the speed changeover switch 15 on the switch box 13 side. As a result, the operability of the operator can be increased and the burden can be reduced, and the safety in driving operation can also be improved.

  Next, FIG. 9 and FIG. 10 show a second embodiment of the present invention. In this embodiment, the same reference numerals are given to the same components as those in the first embodiment described above, and the description thereof will be given. Shall be omitted. However, a feature of the present embodiment is that a speed change pedal 41 is provided on the operator's foot side, and an additional changeover switch for performing a switching operation of the traveling speed by the speed change pedal 41 is configured.

  Here, as shown in FIGS. 9 and 10, the speed switching pedal 41 is provided on the floor plate 5A in the cab 5 and located on the front side of the driver's seat 9, and is pressed by the operator with a foot or the like. That is, the speed change pedal 41 is used in place of the additional changeover switch 23 on the operator's side described in the first embodiment.

  The speed switching pedal 41 is in an open state until the operator performs a pressing operation with his / her foot, sets the traveling speed to the low speed side, and switches to the high speed side when closed by the operator's pressing operation. ing. In addition, a priority lamp 41A that constitutes a second notification unit is provided below or near the speed switching pedal 41, similarly to the priority lamp 23A described in the first embodiment.

  Thus, even in the present embodiment configured as described above, the traveling speed of the vehicle can be easily switched between the low speed side and the high speed side with the tip of the foot by the speed switching pedal 41 provided on the operator's foot side. It is possible to obtain substantially the same effect as that of the first embodiment.

  In the second embodiment, the case where the priority lamp 41A constituting the second notification means is provided below the speed switching pedal 41 has been described as an example. However, the present invention is not limited to this. For example, a configuration in which a priority lamp that constitutes the second notification means is used at a position near the speed switching pedal 41, or at a position separated in the front, rear direction, or left or right direction. Also good. This also applies to the invalid lamp 15A and the priority lamp 23A described in the first embodiment.

  Further, in each of the embodiments, the case where the switch box 13 is provided on the rear side of the right console device 11 has been described as an example. However, the present invention is not limited to this, and for example, a switch box may be provided at the front side of the right console device 11 or at the front and rear positions of the left console device 10. Any configuration may be used.

  On the other hand, in the first embodiment, the case where the invalid lamp 15A is provided on the speed change switch 15 side of the switch box 13 has been described as an example. However, the present invention is not limited to this. For example, when the speed change switch 15 is switched to the high speed side using notification means such as a buzzer or a voice synthesizer, the change operation by the additional change switch 23 is invalid. It is good also as a structure to alert | report. This point is the same as in the first embodiment.

  In the first embodiment, the case where the priority lamp 23A is provided on the additional changeover switch 23 side of the traveling lever 21B has been described as an example. However, the present invention is not limited to this. For example, when the speed change switch 15 is switched to the low speed side using notification means such as a buzzer or a voice synthesizer, priority is given to the switching operation by the additional change switch 23. It is good also as a structure to alert | report. This point is the same as in the first embodiment.

  On the other hand, in each of the above embodiments, the case where the directional control valve 31 shown in FIG. 7 is controlled by the control signal from the controller 32 has been described as an example. However, the present invention is not limited to this. For example, the directional control valve is configured by a hydraulic pilot type directional control valve, and the directional control valve is hydraulically switched with a stroke corresponding to the operation amount of the traveling lever or pedal. It is good also as composition to do.

  Further, the tilt actuator 28 that tilts and drives the capacity variable portion 26A of the hydraulic motor 26 does not need to be electrically controlled by a control signal from the controller 32. For example, the tilt actuator is switched by switching the electric signal to a hydraulic signal. It is good also as a structure which operates by oil pressure.

  Further, in each of the above-described embodiments, the hydraulic excavator 1 in which the swing type front device 7 that can swing left and right is provided on the front side of the upper swing body 3 has been described as an example. However, the present invention is not limited to this. For example, the present invention may be of a type provided with a front device composed of an offset boom type working device, and may be applied to a hydraulic excavator configured to provide a so-called canopy instead of the cab 5. .

  Furthermore, in addition to the hydraulic excavator, it can be applied as a travel control device to various construction machines such as a hydraulic crane, a wheel loader, a bulldozer, or a cargo handling machine. The traveling speed switching control is not limited to the displacement switching of the hydraulic motor, and may be configured to switch the gear stage of the traveling transmission, for example, between the low speed side and the high speed side.

1 is a front view showing a small hydraulic excavator to which a travel control device according to a first embodiment of the present invention is applied. It is a perspective view which expands and shows the cab in FIG. 1 with an internal driver's seat and the left and right console devices. It is the cross-sectional view which expanded the driver's seat in a cab, the left and right console apparatus, etc. from the arrow III-III direction in FIG. It is a fragmentary perspective view which expands and shows the right console apparatus in FIG. 2 with a switch box. FIG. 3 is a perspective view of the traveling lever / pedal device as viewed from the opposite side to FIG. 2. It is a characteristic diagram which shows the relationship between the flow volume of pressure oil, and the rotational speed of a hydraulic motor. It is a control block diagram which shows the travel control apparatus which performs lighting control of a lamp | ramp, and rotational speed control of a hydraulic motor. It is a flowchart which shows the traveling control process of the vehicle by the controller 32 in FIG. It is a perspective view which shows the speed switching pedal by 2nd Embodiment with the driver's seat in a cab, and the left and right console apparatuses. It is a cross-sectional view at the same position as FIG. 3 showing the driver's seat in the cab, the left and right console devices, the speed switching pedal and the like.

Explanation of symbols

1 Excavator (construction machine)
2 Lower traveling body 3 Upper turning body (vehicle body)
4 Turning frame 5 Cab 7 Front device 8 Earth removal device 9 Driver's seat 10 Left console device 10B, 11B Operation lever 11 Right console device 12 Blade lever 13 Switch box 15 Speed change switch 15A Invalid lamp (first notification means)
20 Traveling lever / pedal device 21A, 21B Traveling lever (speed increasing / decreasing means)
22A, 22B Traveling pedal (speed increasing / decreasing means)
23 Additional changeover switch 23A, 41A Priority lamp (second notification means)
Reference Signs List 24 hydraulic pump 26 traveling hydraulic motor 26A capacity variable section 28 tilting actuator 31 direction control valve 32 controller (control means)
41 Speed selector pedal (additional selector switch)

Claims (3)

A self-propelled vehicle body provided with a driver's seat, a switch box provided in the vicinity of the driver's seat and provided with a speed change switch for switching a traveling speed between a high speed side and a low speed side; A speed increasing / decreasing means which is provided in the vehicle body and located on the front side of the driver's seat and which increases / decreases the traveling speed according to an operator's manual operation or stepping operation; a signal from the speed change switch of the switch box; A travel control device for a construction machine comprising control means for variably controlling the travel speed of the vehicle body according to
In addition to the speed change switch of the switch box, the speed increasing / decreasing means is provided with an additional changeover switch for switching the traveling speed between a low speed side and a high speed side,
The control means prioritizes the speed switching operation by the additional changeover switch over the speed changeover switch when the speed changeover switch is switched to the low speed side,
A traveling control device for a construction machine, wherein when the speed change switch is switched to a high speed side, the speed change operation by the speed change switch is given priority over the additional change switch.   The travel control device for a construction machine according to claim 1, further comprising a first notification means for notifying that a switching operation by the additional switch is invalid when the speed switch is switched to a high speed side. .   The traveling of the construction machine according to claim 1 or 2, further comprising: second notification means for notifying that the switching operation by the additional switch is effective when the speed switch is switched to a low speed side. Control device.

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