CN101535687B - Travel control device for hydraulic traveling vehicle - Google Patents

Abstract

A rotational speed pickup 71 (traveling speed detection means), a hydraulic pressure sensor 72 (traveling operation detection means), a hydraulic pressure sensor 73 (drive status detection means), and a voltage sensor 74 (transmission shift position detection means) detect parameters regarding the traveling state of a hydraulic traveling vehicle. A control unit 80, a solenoid proportional valve 81, an engine control system 82, and a motor regulator 33 determine the operating state of the hydraulic traveling vehicle based on the parameters regarding the traveling state, and control the equivalent displacement of the traveling system including a hydraulic traveling motor 14 and the maximum flow rate supplied to the hydraulic traveling motor 14 according to the result of determination. The pump flow rate and motor displacement are controlled according to the traveling state in this way, thereby ensuring favorable traveling performance without degrading the fuel efficiency.

Description

The travel controlling system of hydraulic traveling vehicle

Technical field

The present invention relates to the travel controlling system of hydraulic traveling vehicle, relate in particular to the travel controlling system of the hydraulic traveling vehicles such as wheeled hydraulic excavator with following structure, described structure is: as the driving mechanism of the usefulness of travelling, hydraulic traveling motor with the variable capacity type that is driven by the hydraulic oil of supplying with from oil hydraulic pump is by the travel control of torque of the capacity that changes this hydraulic traveling motor.

Background technique

The travel controlling system of the hydraulic traveling vehicles such as wheeled hydraulic excavator, usually making by hydraulically powered driving motors is variable capacity type, in the situation that the induced pressure (induced pressure travels) of driving motors raises when accelerating, during up-hill journey etc., the capacity of driving motors is increased, to produce needed torque.In addition, when slowing down, adjust circuit pressure (retardation pressure) by the overload relief valve in the hydraulic drive circuit that is located at the usefulness of travelling, by this retardation pressure driving motors is produced braking force, so that the vehicle body braking.In the travel controlling system that consists of like this, weight item with respect to the gradient of vehicle body when descending moves surpasses in the situation of above-mentioned braking force at the vector of direct of travel, vehicle body accelerates under the effect of deadweight, and surpass the maximum speed of predefined vehicle body, therefore affect the life-span of use equipment.

In the travel controlling system of patent documentation 1 record, weight item with respect to the gradient of vehicle body when descending moves surpasses under the state of above-mentioned braking force at the vector of direct of travel easily, the travel neutral condition of pedal of detection, and increased the capacity of driving motors by external command, increase thus braking force, thereby the maximum speed when making descending can not surpass predefined speed.

In addition, in the travel controlling system of patent documentation 2 records, monitor in advance the speed of a motor vehicle, be higher than the capacity that is increased driving motors in the situation of predefined speed by external command in the travelling speed of vehicle, thereby the maximum speed in the time of can making descending equally is no more than predefined speed.

On the other hand, in the travel controlling system of the hydraulic traveling vehicles such as wheeled hydraulic excavator, what have can set the high-power operation mode, sets when needed the high-power operation mode with the maximum speed of raising motor, thereby can guarantee high-power.In such travel controlling system, when having set the high-power operation mode, do not implement various controls in order not increase the speed of a motor vehicle.For example, in the prior art of patent documentation 3 records, when having set the high-power operation mode, reduce vert (capacity) of oil hydraulic pump, the speed of a motor vehicle can not increased.In addition, in patent documentation 3, at driving motors the self-pressure control mechanism that verts is set, when the head pressure of oil hydraulic pump when authorized pressure is above, this self-pressure self-pressure of control mechanism by driving motors of verting increases the capacity of driving motors, and, detect the head pressure of oil hydraulic pump, when detected head pressure when authorized pressure is above, increase the control of the maximum speed of motor, thus, prevent the increase of (when the maximum speed of motor increases) speed of a motor vehicle when the high-power operation mode is set.

Patent documentation 1: Japanese kokai publication hei 8-270788 communique

Patent documentation 2: No. 3631620 communique of Japan's special permission

Patent documentation 3: TOHKEMY 2001-295682 communique

But there are the following problems in above-mentioned prior art.

For example, the driver enters the descending action from flat pavement running stepping on the pedal that travels and do not carry out in the situation of deceleration-operation sometimes, and the action of lasting descending.Under these circumstances, according to the technology of patent documentation 1 record, because the pedal that travels stepped on, so the capacity of driving motors can not increase, so vehicle accelerates, and is difficult to stably carry out the descending action.Technology according to patent documentation 2 records, since when travelling speed than be redefined for maximum speed on level road on an equal basis or this speed more than maximum speed also high after, increase the capacity of driving motors, so vehicle can accelerate to than predefined speed high speed also.

In order to suppress the acceleration of such a vehicle when descending moves, consider fully to increase under the state before the capacity of driving motors switches the capacity of driving motors or the reduction speed ratio of the speed changer that links to each other with driving motors.Yet, if increase the capacity of driving motors or the reduction speed ratio of the speed changer that links to each other with driving motors under the state before the capacity of driving motors switches, then under this state when running at high speed most, be used for making the needed flow of driving system of driving motors rotation to become large, it is large that the hydraulic pressure that produces in the pipeline of driving system loss becomes, and therefore can produce the unfavorable conditions such as energy loss becomes greatly when running at high speed, fuel efficiency reduction.In addition, if prevent this situation, increase the sectional area of pipeline for the pressure loss of the pipe arrangement that reduces driving system, the pipe arrangement space that then has needed vehicle body increases, the shortcomings such as vehicle body maximization.

On the other hand, in the technology of above-mentioned patent documentation 3 records, establish the capacity of timing controlled oil hydraulic pump at the high-power operation mode, or switch mutually with the capacity of the driving motors of realizing by self-pressure and to increase linkedly the control of the maximum speed of motor, thereby can prevent that the speed of a motor vehicle from increasing.But, because as patent documentation 1 record, control system is very complicated, so the volume controlled of oil hydraulic pump is easily brought the problem of cost increase.In addition, switch at the capacity with the driving motors of realizing by self-pressure in the situation of control of the maximum speed that increases linkedly mutually motor, because predefined pump discharge head is carried out the control of engine peak speed and the capacity switching of driving motors as threshold value, therefore, it is inevitable that the deviation of setting and the responsiveness of control are delayed, when the head pressure reduction of oil hydraulic pump so that outside the control of absorption moment of torsion, thereby in the situation that the discharge flow rate of oil hydraulic pump increases, the speed of a motor vehicle might temporarily increase, for this point is improved, under development also have many item subjects to confirmation.

Summary of the invention

Thereby providing, the first purpose of the present invention a kind ofly can come control pump flow and motor capacity in the situation that fuel efficiency is worsened, to guarantee the travel controlling system of the hydraulic traveling vehicle of good rideability according to travelling state.

The second purpose of the present invention provides a kind of increase that can prevent the speed of a motor vehicle when increasing the maximum speed of motor simple and reliablely, and guarantees the travel controlling system of the hydraulic traveling vehicle of good rideability by high-power.

(1) in order to reach above-mentioned the first purpose, the present invention is a kind of drive-control system of hydraulic traveling vehicle, the hydraulic traveling motor that comprises the variable capacity type that drives by the oil hydraulic pump of prime mover driven with by the hydraulic oil of supplying with from this oil hydraulic pump, in this drive-control system, comprise: feeler mechanism, detect the parameter relevant with the travelling state of described hydraulic traveling vehicle; The operating condition decision mechanism is judged the operating condition of described hydraulic traveling vehicle based on the parameter relevant with described travelling state; And control mechanism, control the peak rate of flow that described hydraulic traveling motor is supplied with and the equivalent capacity that comprises the driving system of described hydraulic traveling motor according to the judged result of described operating condition.

Like this, according to controlling the peak rate of flow that the hydraulic traveling motor is supplied with based on the judged result of the operating condition of the hydraulic traveling vehicle of the gain of parameter relevant with the travelling state of vehicle and comprising the equivalent capacity of the driving system of hydraulic traveling motor, thus, can and comprise that the equivalent capacity of the driving system of hydraulic traveling motor is redefined for suitable size with peak rate of flow that the hydraulic traveling motor is supplied with, thereby can in the situation that fuel efficiency is worsened, guarantee good rideability.

For example, under the state that needs slow down, switch to large capacity by the equivalent capacity (for example capacity of hydraulic traveling motor) with driving system, just can guarantee enough braking force, obtain good operation sense.

In addition, only can not guarantee maximum speed at the descending state by the equivalent capacity (for example capacity of driving motors) that merely increases driving system, but, by in the equivalent capacity that increases driving system, increasing the peak rate of flow (peak rate of flow of driving system that the hydraulic traveling motor is supplied with, the discharge flow rate of oil hydraulic pump for example), and be suitable value with both preset amount, then can carry out descending on sloping road with stable speed.

Further, in the accelerated motion before reaching maximum speed, also be to reduce by the equivalent capacity (for example capacity of driving motors) that increases driving system to accelerate needed driving pressure, minimizing is from the leakage flow of the driving system that comprises oil hydraulic motor, thereby can improve the whole efficiency in the accelerated motion, and can also improve sense of acceleration.

In addition, at the state that does not need to slow down with under the state that does not need to accelerate, make the equivalent capacity (for example capacity of driving motors) of driving system drop to lower than the capacity of common needs, can further reduce thus the flow of the needs in order to keep speed, the pressure loss that will produce in the pipe arrangement of driving system is suppressed to lower, thereby can improve fuel efficiency, and owing to the heating that produces because of the pressure loss has also reduced, so can make the needed cooling unit miniaturization of vehicle body.

(2) in above-mentioned (1), for example, described control mechanism is controlled the equivalent capacity of the driving system that comprises described hydraulic traveling motor by the capacity of controlling described hydraulic traveling motor.

(3) in above-mentioned (1), also can be, also be included in the speed changer of the carry-out part setting of described hydraulic traveling motor, described control mechanism is recently controlled the equivalent capacity of the driving system that comprises described hydraulic traveling motor by the deceleration of switching described speed changer.

(4) in addition, in above-mentioned (1), for example, the rotating speed of described control mechanism by controlling described prime mover controlled the peak rate of flow that described hydraulic traveling motor is supplied with to increase and decrease the discharge flow rate of described oil hydraulic pump.

(5) in above-mentioned (1), also can be that the maximum capacity of described control mechanism by controlling described oil hydraulic pump controlled the peak rate of flow that described hydraulic traveling motor is supplied with to increase and decrease the discharge flow rate of described oil hydraulic pump.

(6) in addition, in above-mentioned (1), also can be, also between described oil hydraulic pump and described hydraulic traveling motor, equip direction switch valve, the peak rate of flow that described control mechanism is supplied with described hydraulic traveling motor by described direction switch valve control.

(7) in addition, in above-mentioned (1), preferred described operating condition decision mechanism judges whether described travelling state is at least usually some in travelling state and the descending state, when described travelling state is in described common travelling state, described control mechanism is controlled, so that the peak rate of flow that described hydraulic traveling motor is supplied with is predefined first flow, and the equivalent capacity that makes the driving system that comprises described hydraulic traveling motor is the first capacity, and described the first capacity is for guaranteeing the equivalent capacity of the predefined maximum speed of travelling under described first flow; When described travelling state is in described descending state, described control mechanism is controlled, so that the equivalent capacity of driving system that comprises described hydraulic traveling motor is for than described first the second capacity capacious, and make the peak rate of flow that described hydraulic traveling motor is supplied with for can under described the second capacity, guaranteeing the second flow of described predefined maximum speed.

(8) further, in above-mentioned (1), preferred described operating condition decision mechanism judges whether described travelling state is at least usually some in travelling state and the acceleration mode, when described travelling state is in described common travelling state, described control mechanism is controlled, so that the peak rate of flow that described hydraulic traveling motor is supplied with is first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be the first capacity; When described travelling state is in described acceleration mode, described control mechanism is controlled, so that the peak rate of flow that described hydraulic traveling motor is supplied be second flow larger than described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be than first the second capacity capacious.

(9) in addition, in above-mentioned (1), preferred described operating condition decision mechanism judges whether described travelling state is at least usually some in travelling state and the upward slope state,

When described travelling state is in described common travelling state, described control mechanism is controlled, so that the peak rate of flow that described hydraulic traveling motor is supplied with is first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be the first capacity; When described travelling state is in described upward slope state, described control mechanism is controlled, so that the peak rate of flow that described hydraulic traveling motor is supplied be second flow larger than described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be than first the second capacity capacious.

(10) in addition, in above-mentioned (7)～(9), preferred described operating condition decision mechanism judges also whether described travelling state is in deceleration regime, when described travelling state is in described deceleration regime, described control mechanism is controlled, so that the peak rate of flow that described hydraulic traveling motor is supplied with is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the second capacity.

(11) in addition, in order to reach above-mentioned the second purpose, the present invention is, in above-mentioned (1), described control mechanism has the first control mechanism and the second control mechanism, described the first control mechanism is according to the judged result of described operating condition, and the control of the maximum speed by increasing and decreasing described prime mover is controlled at first flow with the maximum discharge flow rate of described oil hydraulic pump and at least than between the second large flow of this first flow; Described the second control mechanism is according to the judged result of described operating condition, the equivalent capacity that will comprise the driving system of described hydraulic traveling motor is controlled at least the first capacity and than between this first second capacity capacious, the second flow of described oil hydraulic pump and the second capacity of described driving system are set, so that when the equivalent capacity of the driving system that will comprise described hydraulic traveling motor is controlled at the second capacity, vehicle adapts to set travel the second flow of needed flow and described oil hydraulic pump of maximum speed.

Like this, the control of the maximum speed by increasing and decreasing prime mover is controlled at the maximum discharge flow rate of oil hydraulic pump between first flow and the second flow, and the equivalent capacity to the driving system that comprises the hydraulic traveling motor is controlled, and the second flow of oil hydraulic pump and the second capacity of driving system set, so that when the equivalent capacity of the driving system that will comprise the hydraulic traveling motor is controlled at the second capacity, vehicle adapts to set travel the second flow of needed flow and oil hydraulic pump of maximum speed, thus, can prevent the increase of the speed of a motor vehicle when increasing the maximum speed of motor simple and reliablely.

In addition, the maximum discharge flow rate of oil hydraulic pump is controlled in the control of the maximum speed by increasing and decreasing described prime mover, and the equivalent capacity to the driving system that comprises the hydraulic traveling motor is controlled, and thus, can guarantee good rideability by high-power.

For example, under the operational situation that does not need high output, the equivalent capacity (for example capacity of driving motors) of driving system is controlled to be first capacity less than the second capacity, thus, the flow of needed driving system diminishes when travelling to set maximum speed, thereby can be suppressed at the pressure loss that produces in the pipe arrangement of driving system, improve fuel efficiency.

In addition, be increased to the second capacity by the equivalent capacity (for example capacity of driving motors) that makes driving system, thereby when accelerating or go up a slope, need under the situation of tractive force, the driving pressure that needs reduces, reduce from the leakage flow of the driving system that comprises oil hydraulic motor, therefore, the whole efficiency in the action of accelerating, go up a slope improves, and can improve sense of acceleration.

(12) in above-mentioned (11), the preferred first flow of described oil hydraulic pump and the first capacity of described driving system also set, so that when the equivalent capacity of the driving system that will comprise described hydraulic traveling motor is controlled at described the first capacity, vehicle adapts with the travel first flow of needed flow and described oil hydraulic pump of described setting maximum speed.

(13) in above-mentioned (11) or (12), for example, described the second control mechanism is controlled the equivalent capacity of the driving system that comprises described hydraulic traveling motor by the capacity of controlling described hydraulic traveling motor.

(14) in above-mentioned (11) or (12), also can be, also be included in the speed changer of the carry-out part setting of described hydraulic traveling motor, described the second control mechanism is recently controlled the equivalent capacity of the driving system that comprises described hydraulic traveling motor by the deceleration of switching described speed changer.

(15) in above-mentioned (11) or (12), described operating condition decision mechanism judges whether described travelling state is at least usually some in travelling state and the descending state, when described travelling state is in described common travelling state, described the first control mechanism and the second control mechanism are controlled, so that the discharge flow rate of described oil hydraulic pump is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the first capacity; When described travelling state is in described descending state, described the first control mechanism and the second control mechanism are controlled, so that the discharge flow rate of described oil hydraulic pump is described the second flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the second capacity.

(16) further, in above-mentioned (11) or (12), described operating condition decision mechanism judges whether described travelling state is at least usually some in travelling state and the acceleration mode, when described travelling state is in described common travelling state, described the first control mechanism and the second control mechanism are controlled, so that the discharge flow rate of described oil hydraulic pump is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the first capacity; When described travelling state is in described acceleration mode, described the first control mechanism and the second control mechanism are controlled, so that the discharge flow rate of described oil hydraulic pump is described the second flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the second capacity.

(17) in addition, in above-mentioned (11) or (12), described operating condition decision mechanism judges whether described travelling state is at least usually some in travelling state and the upward slope state, when described travelling state is in described common travelling state, described the first control mechanism and the second control mechanism are controlled, so that the discharge flow rate of described oil hydraulic pump is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the first capacity; When described travelling state is in described upward slope state, described the first control mechanism and the second control mechanism are controlled, so that the discharge flow rate of described oil hydraulic pump is described the second flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the second capacity.

(18) in addition, in above-mentioned (15)～(17), described operating condition decision mechanism judges also whether described travelling state is in deceleration regime, when described travelling state is in described deceleration regime, described the first control mechanism and the second control mechanism are controlled, so that the discharge flow rate of described oil hydraulic pump is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the second capacity.

(19) in above-mentioned (1)～(18), as the parameter relevant with the travelling state of described hydraulic traveling vehicle, described feeler mechanism detect at least described hydraulic traveling vehicle travelling speed, be used for driving the mobility operation instruction of described hydraulic traveling motor and the head pressure of described oil hydraulic pump.

The invention effect

By the present invention, according to controlling the peak rate of flow that the hydraulic traveling motor is supplied with based on the judged result of the operating condition of the hydraulic traveling vehicle of the gain of parameter relevant with travelling state and comprising the equivalent capacity of the driving system of hydraulic traveling motor, can in the situation that fuel efficiency is worsened, guarantee good rideability thus.

In addition, according to the present invention, the control of the maximum speed by increasing and decreasing prime mover is controlled at the maximum discharge flow rate of oil hydraulic pump between first flow and the second flow, and the equivalent capacity to the driving system that comprises the hydraulic traveling motor is controlled, and the second flow of oil hydraulic pump and the second capacity of driving system set, so that when the equivalent capacity of the driving system that will comprise the hydraulic traveling motor is controlled at the second capacity, vehicle adapts to set travel the second flow of needed flow and oil hydraulic pump of maximum speed, thus, can prevent the increase of the speed of a motor vehicle when increasing the maximum speed of motor simple and reliablely, and can guarantee good rideability by high-power.

Description of drawings

Fig. 1 shows the figure that uses wheeled hydraulic excavator of the present invention.

Fig. 2 is the whole pie graph of the travel controlling system of the first mode of execution of the present invention.

The travelling of details that Fig. 3 shows motor actuator shown in Figure 2 drives the enlarged view in loop.

Fig. 4 shows the flow chart of whole overview of the processing capacity of motor capacity in the processing capacity of control unit, pump duty control algorithm section.

Fig. 5 shows step S120 and the judgement among the step S130 of Fig. 4 and selects the figure of the details of processing.

Fig. 6 shows the flow chart of the details that the control of the oil hydraulic motor among the step S140 of Fig. 4 processes.

Fig. 7 shows the flow chart of the details that the control of the pump duty control among the step S150 of Fig. 4 processes.

Fig. 8 shows the driving instruction that uses and presses figure with the relation of engine speed increment Delta N in the calculating of engine speed increment Delta N.

Fig. 9 shows the functional block diagram of the overview of the engine control operational part in the processing capacity of control unit.

Figure 10 shows the relation of travel usefulness rotating speed of target characteristic L1, operation rotating speed of target characteristic L2, reference rotation speed characteristic L3, and the figure of the relation of travel usefulness rotating speed of target characteristic L1 and engine speed increment Delta N.

Figure 11 shows the figure of the moment of torsion control characteristic of pump governor.

Figure 12 shows the figure (PQ line chart) of the relation result that can access the capacity by pump governor restriction control oil hydraulic pump, pump pressure and pump duty.

Figure 13 shows the functional block diagram of the overview of the engine control operational part in the processing capacity of the control unit in other mode of executions of the present invention.

Figure 14 show in the target vehicle speed operational part, set, driving instruction presses the figure of the relation of (the accelerator pedal amount of entering into) Pt and target vehicle speed Vt.

Figure 15 show in accelerating the incremental speed operational part, set, vehicle speed deviation Δ V and the figure that accelerates with the relation of revising incremental speed Δ Ns.

Figure 16 shows vehicle speed deviation Δ V and the figure that accelerates with the variation of the relation of revising incremental speed Δ Ns.

Figure 17 shows the figure that judges relation in the situation of accelerated motion and control motor capacity, vehicle speed deviation Δ V and the instruction of motor volume controlled with speed variation Δ V.

Figure 18 shows the functional block diagram of the overview of the engine control operational part in the processing capacity of the control unit in another embodiment of the present invention.

Figure 19 shows the figure of relation that set, pump pressure and engine speed increment Delta Ns in upward slope incremental speed operational part.

Figure 20 shows with judge the to go up a slope figure of relation in the situation of action and control motor capacity, pump pressure and the instruction of motor volume controlled of pump pressure.

Symbol description

1 motor (prime mover)

10 oil hydraulic pumps

11 pump governors

12 control valves (direction switch valve) that travel

14 hydraulic traveling motors

15 speed changers

16 guide's hydraulic powers

The 20 pilot operated loops of travelling

21 accelerator pedals

22a, the 22b pilot valve that travels

23a, 23b pilot line

30 travel drives the loop

31a, 31b main line

32 back pressure valves

33 motor actuator

34a, 34b overload relief valve

35 reciprocable valve

36 valve bodies

37a, 37b throttle valve

38a, 38b safety check

40 speed changer COMM communication

41 power supplys

42 speed change diverter switches

43 solenoid valves

51 oil hydraulic cylinders

52 servovalves

52a, 52b the first and second compression zones

52c, 52d the first and second springs

The 52s Servo Valve's Slide Valve

53 actuating struts

54a, 54b the first pilot line

55 pipelines

71 speed probes (travelling speed feeler mechanism)

72 hydrostatic sensors (mobility operation feeler mechanism)

73 hydrostatic sensors (driving condition detection mechanism)

74 voltage transducers (T/M velocity stage feeler mechanism)

75 engine control penals

76 hydrostatic sensors (the induced pressure feeler mechanism of travelling)

77 travel/the operation selector switch

80 control units

81 electromagnetic proportional valves

82 engine controlling units

83 signaling lines

The 90 rotating speed of target operational parts that travel

91 operative goals rotating speed operational parts

92 datum target rotating speed operational parts

93 target vehicle speed operational parts

94 vehicle speed deviation operational parts

95 accelerate the incremental speed operational part

96 accelerate the rotating speed of target correction portion

97 switching parts

98 maximum selection rule sections

99 rotating speed of target correction portions

Embodiment

The below utilizes the description of drawings embodiments of the present invention.

Fig. 1 shows the figure that uses wheeled hydraulic excavator of the present invention.This wheeled hydraulic excavator has lower traveling body 101 and carries upper rotating body 102 on the top of lower traveling body 101 in the mode that can rotate, is provided with operator cabin 103 and operation with front fixture 104 in upper rotating body 102.Front fixture 104 have with the swing arm 104a on the main body that can be connected in the mode that above-below direction rotates upper rotating body 102, with can about, the fore-and-aft direction mode of rotating be connected on the swing arm 104a dipper 104b and with can about, the fore-and-aft direction mode of rotating is connected to the scraper bowl 104c on the dipper 104b, swing arm 104a is driven by swing arm cylinder 104d, dipper 104b is driven by dipper cylinder 104e, and scraper bowl 104c is moving by scraper bowl cylinder 104f district.Be provided with hydraulic traveling motor 105, speed changer 106 and transmission shaft 107f, 107r at lower traveling body 101, drive front-wheel 108F and trailing wheel 108R by transmission shaft 107f, 107r.

Fig. 2 is the whole pie graph of the travel controlling system of the first mode of execution of the present invention.This travel controlling system comprises: as the diesel engine (being designated hereinafter simply as motor) 1 of prime mover; Oil hydraulic pump 10 by this motor 1 driving; Adjust the pump governor 11 of the capacity (discharge capacity) of oil hydraulic pump 10; The flow of the discharge oil of control oil hydraulic pump 10 and the control valve that travels (direction switch valve) 12 of direction; The pilot operated loop 20 of travelling that the driving instruction of this control valve 12 that travels of generating run is pressed; The travelling of hydraulic traveling motor 14 (the hydraulic traveling motor 105 that is equivalent to Fig. 1) that comprises variable capacity type drives loop 30, above-mentioned hydraulic traveling motor 14 is connected on the control valve 12 that travels via pair of actuator line 13a, 13b, and is driven by the hydraulic oil with control valve 12 controls of travelling; Be connected on the output shaft of hydraulic traveling motor 14, and can switch to according to the action of not shown oil hydraulic cylinder the speed changer 15 (speed changer 106 that is equivalent to Fig. 1) of high speed level and slow speed turbine stage; With optionally the lead oil hydraulic cylinder of speed changer 15 of the hydraulic oil of guide's hydraulic power 16, and speed changer 15 is switched to the speed changer COMM communication 40 of the one party in the at a high speed level and slow speed turbine stage; And the main safety valve 17 of the MDP of restriction oil hydraulic pump 10.

The capacity of pump governor 11 control oil hydraulic pumps 10 is controlled the discharge flow rate of oil hydraulic pump 10 thus so that the absorption moment of torsion of oil hydraulic pump 10 is no more than predefined Maximum Torque, the maximum horsepower (Figure 11 and Figure 12) of control oil hydraulic pump 10.

The pilot operated loop 20 of travelling has the pilot valve of travelling 22a, 22b, above-mentioned pilot valve 22a, the 22b of travelling generates the driving instruction pressure of advancing or retreating according to the amount of entering into (operation amount) of accelerator pedal 21 and the direction of entering into, the driving instruction that advances is pressed the advance side compression zone 12a that is directed to the control valve 12 that travels via pilot line 23a, the control valve 12 that travels is moved to the diagram left, the driving instruction that retreats is pressed via what pilot line 23b was directed to the control valve 12 that travels and is retreated side compression zone 12b, thereby makes the control valve 12 that travels to the right-hand movement of diagram.

Travel and drive loop 30 and comprise: via final controlling element line 13a, 13b hydraulic traveling motor 14 is connected to main line 31a, 31b on the control valve 12 that travels; Be installed in the back pressure valve 32 that travels between control valve 12 and the hydraulic traveling motor 14; Adjust the motor actuator 33 of the capacity (discharge capacity) of hydraulic traveling motor 14; Overload relief valve 34a, the 34b of the maximum pressure of restriction final controlling element line 13a, 13b and main line 31a, 31b; And the reciprocable valve 35 of the on high-tension side pressure of selective extraction final controlling element line 13a, 13b.Final controlling element line 13a, 13b are provided with safety check 18a, the 18b that supply is used.

Back pressure valve 32 is also referred to as brake valve, comprise: have the valve body 36 of neutral position and open position and be arranged on side by side throttle valve 37a, 37b and safety check 38a, 38b on this valve body 36, when descent run etc., carry out under the such operating condition of pumping action at hydraulic traveling motor 14, the exhaust port of valve body 36 is closed, and produces back pressure (retardation pressure) by the effect of throttle valve 37a and overload relief valve 34a at the main line 31b as the discharge side of hydraulic traveling motor 14.

Speed changer COMM communication 40 has power supply 41, speed change diverter switch 42 and solenoid valve 43, when speed change diverter switch 42 is in that the L position of disconnection and switch 42 are operated and when switching to closed H position, above-mentioned solenoid valve 43 is switched from illustrated position by excitation.When solenoid valve 43 is in illustrated position, the oil hydraulic cylinder that not shown gear in the speed changer 15 switches usefulness is connected on the fuel tank, so speed changer 15 is switched at a high speed level, when thereby operation speed change diverter switch 42 solenoid valves 43 are switched from illustrated position, the gear that the hydraulic oil of guide's hydraulic power 16 is sent in the speed changer 15 switches in the oil hydraulic cylinder of usefulness, so speed changer 15 is switched to slow speed turbine stage.

In addition, the travel controlling system of present embodiment, its feature structure is to comprise: be installed on the speed changer 15 speed probe 71 of the travelling speed feeler mechanism of detecting as the rotating speed to the output gear of speed changer 15; Be located on the advance side pilot line 23a in the pilot operated loop 20 of travelling, as the hydrostatic sensor 72 of the mobility operation feeler mechanism that the driving instruction that advances is compressed into the row detection; The hydrostatic sensor 73 of the driving condition detection mechanism of detecting as the head pressure to oil hydraulic pump 10; Be connected between the low speed gear selector switch 42b and solenoid valve 43 of speed changer COMM communication 40 voltage transducer 74 of the T/M velocity stage feeler mechanism of detecting as the signal to low speed gear selector switch 42; Engine control penal (engine control dial) 75; Detection is by the hydrostatic sensor 76 of the on high-tension side pressure of reciprocable valve 35 extractions; Can switch to travelling/operation selector switch 77 of traveling-position and job position; With speed probe 71, hydrostatic sensor 72, hydrostatic sensor 73, voltage transducer 74, engine control penal 75, hydrostatic sensor 76 and travel/the go forward side by side control unit 80 of the fixed calculation process of professional etiquette of the signal input of operation selector switch 77; The electromagnetic proportional valve 81 that is driven by the signal from control unit 80 output; And basis is from the engine controlling unit 82 of the fuel injection amount of the SC sigmal control motor 1 of control unit 80 outputs.

Electromagnetic proportional valve 81 generates the corresponding pilot pressure of output signal with control unit 80 according to the hydraulic oil of guide's hydraulic power 16, and with this pilot pressure as external signal via signaling line 83 to motor actuator 33 outputs.

The travelling of details that Fig. 3 shows motor actuator 33 drives the enlarged view in loop 30.

Motor actuator 33 has oil hydraulic cylinder 51 as control piston, servovalve 52 and the piston rod of oil hydraulic cylinder 51 can be connected to actuating strut 53 on the swash plate 14a of hydraulic traveling motor 14 with moving.Oil hydraulic cylinder 51 moves actuating strut 53 by piston rod is come in and gone out, thereby drives the swash plate 14a of hydraulic traveling motor 14, to control its capacity.The bar chamber 51a of oil hydraulic cylinder 51 is connected on the reciprocable valve 35 that the on high-tension side pressure of final controlling element line 13a, 13b is selected via the first pilot line 54a, 54b.The 51b of bottom compartment of fluid power motor 51 is connected on the servovalve 52 via pipeline 55.

Servovalve 52 has Servo Valve's Slide Valve 52s to the first and second compression zone 52a, the 52b of the right-hand application of force of diagram, and to first spring 52c and the second spring 52d of Servo Valve's Slide Valve 52s to the diagram left application of force, the pressure of the first pilot line 54a, 54b (induced pressure travels) is directed to the first compression zone 52a, and the pressure of the second pilot line 56 (external signal) is directed to the second compression zone 52b.

When the guiding valve 52s of servovalve 52 was in illustrated P1 position, the 51b of bottom compartment of oil hydraulic cylinder 51 was communicated with the pressure release loop 58 of hydraulic traveling motor 14 via pipeline 55, servovalve 52 and pipeline 57a, and the pressure of the 51b of bottom compartment becomes tank pressure.At this moment, oil hydraulic cylinder 51 shrinks under the effect of the pressure of the hydraulic oil of bar side 51a as shown like that, and hydraulic traveling motor 14 is controlled at minimum capacity.

When the guiding valve 52s of servovalve 52 moves to the P2 position in diagram left side, the 51b of bottom compartment of oil hydraulic cylinder 51 is communicated with reciprocable valve 35 via pipeline 55, servovalve 52, pipeline 57b and the first pilot line 54a, 54b, and the pressure of the 51b of bottom compartment becomes the induced pressure that travels that is extracted by reciprocable valve 35.Thus, oil hydraulic cylinder 51 farthest extends, and actuating strut 53 is moved to the diagram left, thereby hydraulic traveling motor 14 is controlled at maximum capacity.

When the guiding valve 52s of servovalve 52 is in position between P1 position and the P2 position, the 51b of bottom compartment of oil hydraulic cylinder 51 is communicated with pipeline 57a and pipeline 57b both sides via pipeline 55, servovalve 52, and the pressure of the 51b of bottom compartment becomes the intermediate pressure of tank pressure and the induced pressure that travels.Thus, oil hydraulic cylinder 51 is elongated to the neutral position, actuating strut 53 is moved to the diagram left, thereby hydraulic traveling motor 14 is controlled at middle capacity.

According to because the effect of feedback rod 59 on the actuating strut 53 and the first spring 52c and the second spring 52d that is located at is led the pressure (induced pressure travels) of the first pilot line 54a, the 54b of the first and second compression zone 52a, 52b and the pressure (external signal) of the second pilot line 56 control the position of the guiding valve 52s of servovalve 52, thereby correspondingly control therewith the capacity of hydraulic traveling motor 14.

Here, the minimum capacity of hydraulic traveling motor 14 is defined as " little ", maximum capacity is defined as " greatly ", with the capacity definition between minimum capacity and the maximum capacity be " in ", in this case, the induced pressure that travels of the first compression zone 52a of leading can comprise " little " by making servovalve 52 action, " in ", the capacity of control hydraulic traveling motor 14 in the four corner of " greatly ", the pressure (external signal) of the second pilot line 56 of the second compression zone 52b that leads by making servovalve 52 actions can with the volume controlled of hydraulic traveling motor 14 " little " (first capacity) or " in " (the second capacity).In addition, the compression area of the compression area of the first compression zone 52a and the second compression zone 52b has predetermined compression face product moment (compression area of the first compression zone 52a is less than the compression area of the second compression zone 52b), and has respectively different control characteristics.With the serve as reasons indicated capacity of the pressure (induced pressure travels) of the first pilot line 54a, 54b of guiding the first compression zone 52a and by the capacity of the larger side in the indicated capacity of the pressure (external signal) of the second pilot line 56 of guiding the second compression zone 52b of the volume controlled of hydraulic traveling motor 14.

The following describes the processing capacity of control unit 80.

Fig. 4 shows the flow chart of the whole overview of the processing capacity of motor capacity, pump duty control algorithm section in the processing capacity of control unit 80.At first, to the control unit 80 inputs various data (parameter) (step S100) relevant with the travelling state of wheeled hydraulic excavator.The various data (parameter) relevant with travelling state comprise the rotating speed by the output gear of speed probe 71 detected speed changers 15, pressed by the hydrostatic sensor 72 detected driving instructions that advance, head pressure (the following suitable pump pressure that is called) by hydrostatic sensor 73 detected oil hydraulic pumps 10, index signal (the following suitable T/M velocity stage that is called) by voltage transducer 74 detected low speed gear selector switches 42, with by the hydrostatic sensor 76 detected induced pressures etc. that travel.Be converted into the travelling speed of wheeled hydraulic excavator by the rotating speed of the output gear of speed probe 71 detected speed changers 15, and be used as travelling speed.

Then, the control unit 80 usefulness various data (parameter) relevant with travelling state are judged the operating condition (step S120) of wheeled hydraulic excavator, and select the required flow (motor capacity) of hydraulic traveling motor 14 and the required flow (pump duty) (step S130) of oil hydraulic pump 10 according to this operating condition.

Fig. 5 shows the judgement among step S120 and the step S130 and selects the figure of the details of processing.In step S120 and step S130 as the operating condition that judges, and select motor capacity and pump duty.

[travelling state 1]

Travelling speed (Km/h) is not limit

2/3 (together lower) of driving instruction pressure＞supreme command pressure P tmax

Pump pressure (Mpa)＞20

The T/M velocity stage is not limit

Be judged as in this case accelerated motion, and following selection motor capacity and pump duty.

In the motor capacity (the second capacity)

Pump duty large (the second flow)

[travelling state 2]

Travelling speed (Km/h)＞10

Driving instruction presses＞2/3

Pump pressure (Mpa)＞25

The T/M velocity stage is not limit

Be judged as in this case the upward slope state, and following selection motor capacity and pump duty.

In the motor capacity (the second capacity)

Pump duty large (the second flow)

[travelling state 3]

Travelling speed (Km/h)＞10

Driving instruction presses＜1/3

Pump pressure (Mpa) is not limit

T/M velocity stage Hi

Be judged as in this case speed-down action, and following selection motor capacity and pump duty.

In the motor capacity (the second capacity)

Pump duty little (first flow)

[travelling state 4]

Travelling speed (Km/h)＞10

Driving instruction presses＞2/3

Pump pressure (Mpa)＜3

T/M velocity stage Hi

Be judged as in this case the descending state, and following selection motor capacity and pump duty.

In the motor capacity (the second capacity)

Pump duty large (the second flow)

[travelling state 5]

State beyond the combinations thereof

Be judged as in this case acceleration, upward slope, deceleration, descending operating condition in addition, and following selection motor capacity and pump duty.

Motor capacity little (the first capacity)

Pump duty little (first flow)

Get back to Fig. 4, control unit 80 is controlled so that hydraulic traveling motor 14 is desired volume (step S140), and controls so that oil hydraulic pump 10 is required flow (step S150).

Fig. 6 shows the flow chart of the details that the control of the hydraulic traveling motor 14 among the step S140 processes.Control unit 80 judge the desired volume of the hydraulic traveling motor 14 of in step S130, selecting whether be " in " (step S142), if for " in " then do not carry out any operation, return this judgements processing.At this moment, electromagnetic proportional valve 81 is in illustrated OFF position, with the second compression zone 52b of tank pressure as the servovalve 52 of external signal steerable motor regulator 33.Thus, detected and be applied to by reciprocable valve 35 in the situation of induced pressure less than the pressure corresponding with motor capacity " little " of travelling of the second compression zone 52a, servovalve 52 actions switch to small capacity to illustrated P1 position with hydraulic traveling motor 14.If the desired volume of the hydraulic traveling motor 14 of in step S130, selecting for " in ", then calculate for the volume controlled of hydraulic traveling motor 14 for " in " desired value of needed pilot pressure (external signal) from electromagnetic proportional valve 81 outputs, and output driving signal (the motor capacity command signal corresponding with this desired value; Voltage signal) Em (step S144).

Here, as described above, the first and second compression zone 52a, the 52b of servovalve 52 have respectively the different control characteristic corresponding from compression area, and the induced pressure that will the travel first compression zone 52a that leads is with the guiding valve 52s of control servovalve 52.Therefore, when the desired value of calculating the pilot pressure (external signal) of exporting from electromagnetic proportional valve 81, in order to revise the amount of the induced pressure that travels on the first compression zone 52a, the following desired value of obtaining pilot pressure.

The desired value of pilot pressure is Pc if make, and the pilot pressure that only is used for drawing according to the control signal from electromagnetic proportional valve 81 outputs target capacity " " is Po, and the induced pressure that travels is Pt to the scaled value of pilot pressure, then

Po＝Pt+Pc

Thus,

Pc＝Po-Pt (1)

Here, Po is the value that calculated in advance goes out, and Pt can be according to being obtained by the hydrostatic sensor 35 detected induced pressures that travel.

Electromagnetic proportional valve 81 generates the suitable pilot pressure of Pc according to the driving signal Em corresponding with the desired value of the above-mentioned pilot pressure of obtaining like that, and this pilot pressure is directed to the second compression zone 52b of the servovalve 52 of motor actuator 33 as external signal.Thus, servovalve 52 to the action of P2 position side, switches to middle capacity with hydraulic traveling motor 14 from illustrated position from the P1 position.

Fig. 7 shows the flow chart of the details that the control of the pump duty control among the step S150 processes.It is the discharge flow rate that increases oil hydraulic pump 10 by the maximum speed that increases motor 1 that pump duty among the step S150 is controlled.

At first, control unit 80 judges whether the required flow (pump duty) of the oil hydraulic pump 10 of selecting is " greatly " (step S152) in step S130, if then do not carry out any operation for " greatly ", returns this judgement and processes.If the pump duty of selecting is " greatly ", then driving instruction pressure is at this moment gone out engine speed increment Delta N (step S154) with reference to the schematic calculation that has been stored in the storage in step S130.

Fig. 8 shows the driving instruction that uses and presses figure with the relation of engine speed increment Delta N in the calculating of engine speed increment Delta N.The driving instruction relation with engine speed increment Delta N of pressing is set to: during 2/3 the value of the supreme command pressure P tmax when driving instruction forces down in pedal complete operation, engine speed increment Delta N is zero, when driving instruction is pressed as more than 2/3 of supreme command pressure P tmax (instruction area of running at high speed), engine speed increment Delta N increases along with the rising of driving instruction pressure, until become certain pilot pressure value (for example 5/6 of Ptmax), then, engine speed increment Delta N reduces along with the rising of driving instruction pressure.

Next, the control unit 80 engine speed increment Delta N that will calculate in step S 154 exports to the engine control operational part (step S156) of control unit 80.

Fig. 9 shows the functional block diagram of the overview of engine control operational part.The engine control operational part has each function of the rotating speed of target operational part 90 that travels, operative goals rotating speed operational part 91, datum target rotating speed operational part 92, switching part 97, maximum selection rule section 98 and rotating speed of target correction portion 99.

Rotating speed of target operational part 90 outputs of travelling press (amount of entering into of accelerator pedal) proportional travelling to use target engine speed Nt with driving instruction, 91 outputs of operative goals rotating speed operational part are pressed (amount of entering into of accelerator pedal) proportional operation target engine speed Nw with driving instruction, the proportional target engine speed Nc of operation amount of 92 outputs of datum target rotating speed operational part and engine control penal 75.

That is, travel 91 outputs of rotating speed of target operational part 90 and operative goals rotating speed operational part according to being pressed Pt by pressure transducer 72 detected driving instructions and definite travel rotating speed of target Nt and operative goals rotational speed N w corresponding to function (rotary speed property) L1, the L2 of the rotating speed of target of motor 1.Datum target rotating speed operational part 92 output according to the signal Fc of the operation amount that exists with ... engine control penal 75 and corresponding to function (rotary speed property) L3 of the rotating speed of target of motor 1 definite datum target rotational speed N c.

Selection portion 97 according to travel/selection instruction of operation selector switch 77 select from rotating speed of target operational part 90 outputs of travelling based on characteristic L1 travel rotating speed of target Nt and from 91 outputs of operative goals rotating speed operational part based on the side the operative goals rotational speed N w of characteristic L2, and output.That is, when travel/when operation selector switch 77 switched to traveling-position, selectivity characteristic L 1; When switching to job position, selectivity characteristic L2.To be input to maximum selection rule section 98 at the rotating speed of target Nf1 that selection portion 97 is selected, maximum selection rule section 98 select this rotating speed of target Nf1 with from 92 outputs of datum target rotating speed operational part based on the larger side the rotating speed of target Nc of characteristic L3, and output.

Rotating speed of target correction portion 99 will be from the rotating speed of target Nf2 and the engine speed increment Delta N addition of exporting among the step S156 of Fig. 7 of maximum selection rule section 98 outputs, obtain final rotating speed of target Nf3, and this final rotating speed of target Nf3 is exported to engine controlling unit 82.

Figure 10 shows the figure of the relation of characteristic L1～L3 and engine speed increment Delta N.

Characteristic L1 be exist with ... accelerator pedal 21 the amount of entering into, roadablely travel that to use rotating speed of target characteristic, characteristic L2 be the operation rotating speed of target characteristic amount of entering into, that be suitable for operation that exists with ... accelerator pedal 21.Operation refers to, the use operation digging operation of fixture etc.L2 compares with characteristic, the increment rate of the rotating speed of target of characteristic L1, is that the slope of characteristic is more precipitous.Characteristic L3 is reference rotation speed characteristic operation amount, that be suitable for operation that exists with ... engine control penal 75.Characteristic L2, L3, its slope, to be engine speed equate with respect to the variable quantity of operation amount, and racing speed Ncid, also equate with respect to the rotating speed of target Ncmax of capacity operation.

In addition, in motion, if output engine incremental speed Δ N in the said pump flow control calculation process (the step S120 among the figure, S130, S150) when having selected to travel the HP pattern, then in the HP pattern rotating speed of target correction portion 99 of travelling, at this increment Delta of addition N from the rotating speed of target Nf2 of maximum selection rule section 98 outputs.Consequently, when driving instruction was pressed as more than 2/3 of supreme command pressure P tmax (instruction area of running at high speed), the characteristic of travelling with the counterpart of rotating speed of target characteristic L1 switched to L1B from L1A.Namely, when in step S130, having selected pump duty " little ", as travelling with the rotating speed of target characteristic and setting property L1A of the instruction area of running at high speed, when having selected pump duty " greatly ", as travelling with the rotating speed of target characteristic and setting property L1B of the instruction area of running at high speed.

Here, the increment rate of the rotating speed of target of characteristic L1B, be that the slope ratio characteristic L1A of characteristic is more precipitous, and the maximum speed Ntmax1 of the maximum speed Ntmax2 ratio characteristic L1A of characteristic L1B is high.For example, maximum speed Ntmax1 is 1650rpm, and maximum speed Ntmax2 is 2000rpm.In addition, the result that the slope of characteristic L1B is more precipitous is, driving instruction is pressed in and arrives before the supreme command pressure P tmax (for example 5/6 of Ptmax) and arrives maximum speed Ntmax2.This feature L1B's is corresponding with the relation of driving instruction pressure P t shown in Figure 8 and engine speed increment Delta N with respect to the variation (increase) of the rotating speed of target of feature L1A.

Figure 11 shows the figure of the moment of torsion control characteristic of pump governor 11.Transverse axis is the head pressure (pump pressure) of oil hydraulic pump 10, and the longitudinal axis is the capacity (verting of discharge capacity or swash plate) of oil hydraulic pump 10.

When in the scope of head pressure at P0～P1 of oil hydraulic pump 10, pump governor 11 does not absorb moment of torsion control, and the capacity of oil hydraulic pump 10 be the steady state value qmax of maximum.When the head pressure of oil hydraulic pump 10 surpassed P1, pump governor 11 absorbed moment of torsion control, and the capacity of oil hydraulic pump 10 reduces along characteristic line A.Control thus the absorption moment of torsion of oil hydraulic pump 10, make it be no more than the prescribed torque (Maximum Torque) shown in the moment of torsion constant curve TA.When the head pressure of oil hydraulic pump 10 rose to Pmax, main safety valve 17 actions continued to rise with the restrictive pump head pressure.

Figure 12 shows the figure (PQ line chart) of the relation result that can access as described above the capacity by pump governor 11 restriction control oil hydraulic pumps 10, pump pressure and pump duty.Transverse axis is the head pressure (pump pressure) of oil hydraulic pump 10, and the longitudinal axis is the discharge flow rate (pump duty) of oil hydraulic pump 10.

The discharge flow rate of oil hydraulic pump is the capacity of oil hydraulic pump and the long-pending function of rotating speed, even pump capacity is identical, when engine speed increased, correspondingly pump duty also increased.In Figure 12, solid line is the PQ line chart of engine speed when being maximum speed Ntmax1, and dotted line is the PQ line chart of engine speed when being maximum speed Ntmax2.When engine speed was maximum speed Ntmax1, when the head pressure of oil hydraulic pump 10 was in the scope of P0～P1, pump duty was the peak rate of flow Qmax1 corresponding with the maximum capacity qmax of oil hydraulic pump 10; When the head pressure of oil hydraulic pump 10 surpassed P1, pump duty reduced along characteristic line A1 along with the minimizing of pump capacity.Can control thus the absorbed horsepower of oil hydraulic pump 10, the distribution horsepower when making it be no more than engine speed and be maximum speed Ntmax1.When engine speed is maximum speed Ntmax2, when the head pressure of oil hydraulic pump 10 is in the scope of P0～P1, pump duty be the peak rate of flow Qmax2 corresponding with the maximum capacity qmax of oil hydraulic pump 10 (＞Qmax1); When the head pressure of oil hydraulic pump 10 surpassed P2, pump duty reduced along characteristic line A2 along with the minimizing of pump capacity.Can control thus the absorbed horsepower of oil hydraulic pump 10, the distribution horsepower when making it be no more than engine speed and be maximum speed Ntmax2.In addition, when engine speed is maximum speed Ntmax2, compare when being maximum speed Ntmax1 with engine speed, pump duty is corresponding to the increasing amount of maximum speed and increased on the whole flow Δ Q, and peak rate of flow Qmax2 has also increased Δ Q than peak rate of flow Qmax1.

Like this, in the present embodiment, in the pump duty control algorithm is processed, when selecting pump duty " little ", set L1A as the travelling the rotating speed of target characteristic of high speed instruction zone, the maximum speed of the motor 1 of this moment is Ntmax1, and the peak rate of flow of oil hydraulic pump 10 is the Qmax1 corresponding with this maximum speed Ntmax1; When selecting pump duty " greatly ", set L1B as the travelling the rotating speed of target characteristic of high speed instruction zone, the maximum speed of the motor 1 of this moment is Ntmax2, and the peak rate of flow of oil hydraulic pump 10 increases to the Qmax2 corresponding with this maximum speed Ntmax2.

Here, in the present embodiment, the relation of the motor capacity " little " of following setting hydraulic traveling motor 14 and the peak rate of flow Qmax1 of oil hydraulic pump 10, that is: make when having selected motor capacity " little " vehicle equate (adapting) with the travel peak rate of flow Qmax1 of the oil hydraulic pump 10 of flow when having selected pump duty " little " of needed hydraulic traveling motor 14 of the maximum speed of setting, and, the motor capacity of following setting hydraulic traveling motor 14 " in " with the relation of the peak rate of flow Qmax2 of oil hydraulic pump 10, that is: make selected the motor capacity " in " time vehicle equate (adapting) with the travel peak rate of flow Qmax2 of the oil hydraulic pump 10 of flow when having selected pump duty " greatly " of needed hydraulic traveling motor 14 of the maximum speed of setting.In other words, hydraulic traveling motor 14 is controlled to be motor capacity " little ", and the relation of the peak rate of flow Qmax1 of the motor capacity " little " of setting hydraulic traveling motor 14 and oil hydraulic pump 10, so that the maximum speed of maximum travel speed for setting of the vehicle of the maximum discharge flow rate of oil hydraulic pump 10 when being controlled as pump duty " little ", and, with hydraulic traveling motor 14 be controlled to be the motor capacity " in ", and set hydraulic traveling motor 14 the motor capacity " in " with the relation of the peak rate of flow Qmax2 of oil hydraulic pump 10 so that the maximum travel speed of the vehicle of the maximum discharge flow rate of oil hydraulic pump 10 when being controlled as pump duty " greatly " is the maximum speed of setting.

Consequently, the following capacity " little " of having set hydraulic traveling motor 14 and " greatly " and the peak rate of flow Qmax1 of oil hydraulic pump 10, the relation of Qmax2, that is: the maximum travel speed that makes the vehicle when selecting motor capacity " little " and selecting pump duty " little " with select the motor capacity " in " and the maximum travel speed of vehicle when selecting pump duty " greatly " about equally.

In above-mentioned, speed probe 71 (travelling speed feeler mechanism), hydrostatic sensor 72 (mobility operation feeler mechanism), hydrostatic sensor 73 (driving the condition detection structure), voltage transducer 74 (T/M speed detecting mechanism) has consisted of the feeler mechanism for detection of the parameter relevant with the travelling state of hydraulic traveling vehicle, the step S100 shown in Figure 4 of control unit 80 and the processing of S120 have consisted of the operating condition decision mechanism of judging the operating condition of hydraulic traveling vehicle according to the detected parameter relevant with travelling state of feeler mechanism, the processing of the step S130 shown in Figure 4 of control unit 80～S150, electromagnetic proportional valve 81, engine controlling unit 82 and motor actuator 33 have consisted of according to the judged result of above-mentioned operating condition to be controlled to the peak rate of flow of hydraulic traveling motor 14 supplies and the control mechanism of the equivalent capacity of the driving system that comprises hydraulic traveling motor 14.

In addition, the step S120 shown in Figure 4 of control unit 40, S130, function and the engine controlling unit 82 of the function of S150 and rotating speed of target correction portion 99 shown in Figure 9 have consisted of the first control mechanism, the control of the maximum speed of this first control mechanism by increasing and decreasing motor 1 (prime mover) is controlled at the maximum discharge flow rate of oil hydraulic pump 10 between first flow (the peak rate of flow Qmax1 during pump duty " little ") and second flow (the peak rate of flow Qmax2 during pump duty " greatly ") larger than this first flow at least, the step S120 shown in Figure 4 of control unit 80, S130, the equivalent capacity that the function of S140 and electromagnetic proportional valve 81 and motor actuator 33 have consisted of the driving system that will comprise hydraulic traveling motor 14 is controlled at the first capacity (motor capacity " little ") and at least than the second control mechanism between this first second capacity capacious (motor capacity " greatly ").

And, set the second flow of oil hydraulic pump 10 and the second capacity of driving system, so that vehicle adapts to set travel second flow (the peak rate of flow Qmax2 during pump duty " greatly ") of needed flow and oil hydraulic pump 10 of maximum speed when the equivalent capacity of the driving system that will comprise hydraulic traveling motor 14 is controlled at above-mentioned the second capacity (motor capacity " in "), and set the first flow and the first capacity of above-mentioned driving system of oil hydraulic pump 10, so that vehicle adapts with the travel first flow (the peak rate of flow Qmax1 during pump duty " little ") of needed flow and oil hydraulic pump 10 of setting maximum speed when the equivalent capacity of the driving system that will comprise hydraulic traveling motor 14 is controlled at above-mentioned the first capacity (motor capacity " little ").

Below, the action of present embodiment is described.

[during acceleration]

At first, the situation that vehicle accelerates according to driver's operation from halted state is described.

When vehicle accelerates, press above 2/3 of supreme command pressure P tmax at driving instruction, and the head pressure of oil hydraulic pump 10 is higher than under the state of 20Mpa, control unit 80 is judged as accelerated motion, selection motor capacity " in " (the second capacity) and pump duty " greatly " (the second flow), and control, so that the maximum discharge flow rate (engine speed) of the capacity of hydraulic traveling motor 14 and oil hydraulic pump 10 becomes respectively capacity and the flow of this selection.At this moment, in aforesaid (1) formula, be higher than when only obtaining anxious acceleration of pilot pressure Po of target capacity " " by the control signal from electromagnetic proportional valve 81 outputs at the scaled value Pt of induced pressure to pilot pressure that travel, because the desired value Pc of pilot pressure is negative value, therefore not to electromagnetic proportional valve 81 output drive signals, 52 induced pressures that travel by guiding the first compression zone 52a of servovalve are controlled.Thus, the capacity of hydraulic traveling motor 14 be controlled as with travel induced pressure accordingly greater than " in " capacity.

Thus, since the capacity of hydraulic traveling motor 14 be controlled as predetermined capacity " in " or than its large capacity, needed driving pressure step-down when therefore accelerating, reduce from the leakage flow of the driving system that comprises hydraulic traveling motor 14, thereby the whole efficiency in the accelerated motion improves, and can improve sense of acceleration.

In addition, although owing to the capacity of hydraulic traveling motor 14 increases the temporary transient change of the required flow that makes the needed driving system of maximum speed greatly, thereby but increase and the pump duty increase by the increase motor output of engine speed, therefore can accelerate to swimmingly the maximum speed of setting.

Further, when the accelerated motion end, when the head pressure of oil hydraulic pump 10 reduced, control unit 80 was judged as " usually ", and motor capacity and pump duty are switched to respectively " little ".At this moment, since set peak rate of flow Qmax2 and motor capacity " in " relation, so that in pump duty for " greatly " (peak rate of flow Qmax2) and motor capacity be " in " time the maximum travel speed maximum speed that equals to set, and, set the relation of peak rate of flow Qmax1 and motor capacity " little ", so that (that is to say in the pump duty maximum speed that the maximum travel speed during for " little " equals to set for " little " (peak rate of flow Qmax1) and motor capacity, set second capacity (motor capacity " in ") of driving system and second flow (the peak rate of flow Qmax2 during pump duty " greatly ") of oil hydraulic pump 10, so that vehicle adapts to set travel second flow (the peak rate of flow Qmax2 during pump duty " greatly ") of needed flow and oil hydraulic pump 10 of maximum speed when the equivalent capacity of the driving system that will comprise hydraulic traveling motor 14 is controlled at the second capacity (motor capacity " in "), and, set first capacity (motor capacity " little ") of driving system and the first flow (the peak rate of flow Qmax1 during pump duty " little ") of oil hydraulic pump 10, so that vehicle adapts to set the travel first flow (the peak rate of flow Qmax1 during pump duty " little ") of needed flow and oil hydraulic pump 10 of maximum speed when the equivalent capacity with driving system is controlled at the first capacity (motor capacity " little ")), therefore can prevent that the speed of a motor vehicle is increased to more than the maximum speed of setting, and can guarantee good vehicle body acceleration performance by high-power.

[upward slope]

The following describes the situation that vehicle body enters the upward slope state.

During up-hill journey, when travelling speed is lower than 10Km/h, driving instruction is pressed and is surpassed 2/3 of supreme command pressure P tmax, and when the head pressure of oil hydraulic pump 10 is higher than 25Mpa, control unit 80 is judged as the upward slope state, selection motor capacity " in " (the second capacity) and pump duty " greatly " (the second flow), and control, so that the discharge flow rate (engine speed) of the capacity of hydraulic traveling motor 14 and oil hydraulic pump 10 becomes respectively capacity and the flow of this selection.In this case, when the induced pressure that travels when when going up a slope on the sloping road of heavy gradient is high, also be by guiding servovalve 52 the first compression zone 52a travel induced pressure with the volume controlled of hydraulic traveling motor 14 for than " in " large capacity.

Thus, the capacity of hydraulic traveling motor 14 be increased at least predetermined capacity " in ", and engine speed increases, motor output increases, pump duty increases, the speed of a motor vehicle in the time of therefore can guaranteeing good upward slope by high-power.

In addition, when the upward slope release, when the head pressure of oil hydraulic pump 10 reduced, control unit 80 was judged as " usually ", and motor capacity and pump duty are switched to respectively " little ".At this moment, owing to set peak rate of flow Qmax2 and motor capacity and be " in " relation, so that in pump duty for " greatly " and motor capacity be " in " time the maximum travel speed maximum speed that equals to set, and, setting peak rate of flow Qmax1 and motor capacity is the relation of " little ", so that in the pump duty maximum speed that the maximum travel speed during for " little " equals to set for " little " (peak rate of flow Qmax1) and motor capacity, therefore, the speed of a motor vehicle in the time of can guaranteeing good upward slope by high-power, and can prevent that the speed of a motor vehicle is increased to more than the maximum speed of setting.

[deceleration]

The situation that the following describes when travelling on smooth road or slow down during descending.

During deceleration, when travelling speed is higher than 10Km/h, driving instruction forces down in 1/3 of supreme command pressure P tmax, and when the T/M velocity stage is in Hi (at a high speed level), control unit 80 is judged as deceleration regime, selection motor capacity " in " (the second capacity) and pump duty " little " (first flow), and control, so that the discharge flow rate (engine speed) of the capacity of hydraulic traveling motor 14 and oil hydraulic pump 10 becomes respectively capacity and the flow of this selection.

Like this, control unit 80 after detecting the running speed-reduction state, make at once the capacity of driving motors be increased to predetermined capacity " in ".Thus, even being in the descending state, vehicle body also can obtain enough hydraulic braking force.In addition, according to travelling speed and the T/M velocity stage of vehicle, only increase when needed the equivalent capacity of driving system, can guarantee enough hydraulic braking force thus, and can prevent the deterioration of the deceleration impact that causes owing to braking force is excessive etc., operating characteristics.

[descending]

The following describes the situation that under the driver does not carry out the situation of deceleration-operation, enters the descending action.

During descending, when travelling speed is higher than 10Km/h, driving instruction is pressed and is higher than 2/3 of supreme command pressure P tmax, the head pressure of oil hydraulic pump 10 is lower than 3Mpa, and when the T/M velocity stage is in Hi (at a high speed level), control unit 80 is judged as the descending state, selection motor capacity " in " (the second capacity) and pump duty " greatly " (the second flow), and control, so that the discharge flow rate (engine speed) of the capacity of hydraulic traveling motor 14 and oil hydraulic pump 10 becomes respectively capacity and the flow of this selection.

Thus, detect descending action after, make the capacity of hydraulic traveling motor 14 be increased to predetermined capacity " in ", thereby and the engine speed discharge flow rate that increases oil hydraulic pump 10 also be increased to predetermined value " greatly ".Here, set peak rate of flow Qmax2 and motor capacity " in " relation, so that in pump duty for " greatly " (peak rate of flow Qmax2) and motor capacity be " in " time the maximum travel speed maximum speed that equals to set, and, set the relation of peak rate of flow Qmax1 and motor capacity " little ", so that the maximum speed that the maximum travel speed when pump duty is " little " for " little " (peak rate of flow Qmax1) and motor capacity equals to set.Thus, can under the state that keeps maximum speed, carry out the descending action, and can prevent that by the increase of hydraulic braking force vehicle body from accelerating to surpass predetermined maximum speed because of deadweight.

[effect]

As described above, according to present embodiment, detect the parameter relevant with the travelling state of vehicle to judge the operating condition of vehicle, according to the capacity of this judged result control hydraulic traveling motor 14 and the maximum discharge flow rate of oil hydraulic pump 10, therefore, can in the situation that does not reduce fuel efficiency, guarantee good rideability.

That is, under the state that needs slow down, the capacity by the oil hydraulic motor 14 that will travel increase to " in ", just can guarantee enough braking force, and obtain good operation feeling.

In addition, can not guarantee maximum speed at the descending state although only merely increase the capacity of hydraulic traveling motor 14, but by in the capacity that increases hydraulic traveling motor 14, the maximum discharge flow rate of oil hydraulic pump 10 being controlled to be " greatly " to increase the peak rate of flow of driving system, just can carry out descending on sloping road with stable speed and move.

Further, until reach in the accelerated motion of maximum speed, also be to reduce by the capacity that increases hydraulic traveling motor 14 to accelerate needed driving pressure, thereby the leakage flow that comprises the driving system of hydraulic traveling motor 14 reduces, whole efficiency in the accelerated motion improves, and can improve sense of acceleration.

In addition, at the state that does not need to slow down with under the state that does not need to accelerate, arrive " little " less than the capacity of common needs by the volume lowering with hydraulic traveling motor 14, can further reduce be used to the necessary flow of the speed of keeping, the pressure loss that produces in the pipe arrangement with driving system suppresses lowlyer, thereby improve fuel efficiency, and reduced the heating that produces because of the pressure loss, therefore can also make the needed cooling unit miniaturization of vehicle body.

Further, the maximum discharge flow rate of oil hydraulic pump 10 is controlled in the control of the maximum speed by increasing motor 1, and the capacity of control hydraulic traveling motor 14, and set second capacity (motor capacity " in ") of driving system and second flow (pump duty " greatly ") of oil hydraulic pump 10, so that when with the volume controlled of hydraulic traveling motor 14 for " in " time vehicle adapt to set travel second flow (the peak rate of flow Qmax2 during pump duty " greatly ") of needed flow and oil hydraulic pump 10 of maximum speed, therefore, can be simply and prevent that effectively the speed of a motor vehicle increases when increasing the maximum speed of motor 1.

In addition, the maximum discharge flow rate of oil hydraulic pump 10 is controlled in the control of the maximum speed by increasing motor 1, and the capacity of control hydraulic traveling motor 14, thus, can guarantee good rideability by high-power.

With Figure 13～Figure 17 other mode of executions of the present invention are described.About present embodiment, the operating condition beyond the accelerated motion is identical with the first mode of execution, controls motor capacity and pump duty with judgement selection function shown in Figure 5, when accelerated motion, utilizes vehicle speed deviation to control motor capacity and pump duty.

At first, to having utilized pump duty control vehicle speed deviation, in the accelerated motion to describe.In the present embodiment, also be to carry out pump duty control by the maximum speed that changes motor.

Figure 13 shows and has assembled the functional block diagram that is used for utilizing vehicle speed deviation overview of the engine control operational part of the function of control pump duty when accelerated motion.Among the figure, to the identical reference character of parts mark that is equal to parts shown in Figure 9.

Engine control operational part in the present embodiment also has each function of target vehicle speed operational part 93, vehicle speed deviation operational part 94, acceleration incremental speed operational part 95 and acceleration rotating speed of target correction portion 96 on the basis of each function with the rotating speed of target operational part 90 that travels shown in Figure 9, operative goals rotating speed operational part 91, datum target rotating speed operational part 92, switching part 97, maximum selection rule section 98, rotating speed of target correction portion 99.

93 outputs of target vehicle speed operational part are pressed target vehicle speed Vt corresponding to (the accelerator pedal amount of entering into) with driving instruction, vehicle speed deviation operational part 94 deducts actual travelling speed Vr and calculates vehicle speed deviation Δ V from this its target vehicle speed Vt, accelerating 95 calculating of incremental speed operational part accelerates with revising incremental speed Δ Ns accordingly with this vehicle speed deviation Δ V, accelerate rotating speed of target correction portion 96 this increment Delta Ns and the rotating speed of target Nt that travels are revised mutually, and export the rotating speed of target Nt1 that travels.

Figure 14 shows the figure that the driving instruction of setting is pressed the relation of (the accelerator pedal amount of entering into) Pt and target vehicle speed Vt in target vehicle speed operational part 93.Target vehicle speed Vt presses the rising of Pt along with driving instruction and increases.

Figure 15 shows the vehicle speed deviation Δ V that sets and the figure that accelerates with the relation of revising incremental speed Δ Ns in accelerating incremental speed operational part 95.Before speed variation Δ V reaches the first value Δ V1, engine speed increment Delta Ns is zero, when speed variation Δ V surpasses the first value Δ V1, be judged as accelerated motion, the increase of increment Delta Ns and speed variation Δ V increases pro rata rapidly, when speed variation Δ V surpassed the second value Δ V2, increment Delta Ns was maximum value Δ Nsmax.

Figure 16 shows vehicle speed deviation Δ V and the figure that accelerates with the variation of the relation of revising incremental speed Δ Ns.Before vehicle speed deviation Δ V reached value Δ V3, increment Delta Ns was minimum value Nsmin, and when speed variation Δ V exceedance Δ V3, increment Delta Ns is with the stepped maximum value Δ Nsmax that is increased to.

As described above, with increment Delta Ns and the rotating speed of target Nt addition of travelling, correspondingly, final rotating speed of target Nf3 increases in accelerating rotating speed of target correction portion 96.Thus, with the first mode of execution in the same manner, when output increment Δ Ns, the maximum speed of motor 1 rises to Ntmax2 from Ntmax1, the maximum discharge flow rate of oil hydraulic pump 10 is increased to Qmax2 from Qmax1, when the output of increment Delta Ns stopped, the maximum speed of motor 1 was got back to Ntmax1, and the maximum discharge flow rate of oil hydraulic pump 10 reduces to Qmax2.

The below describes the motor volume controlled in the accelerated motion that has utilized vehicle speed deviation.

Figure 17 shows the figure of the relation of vehicle speed deviation Δ V and the instruction of motor capacity.Before speed variation Δ V reached the second value Δ V2, the instruction of motor capacity was " little ", when speed variation Δ V surpasses the second value Δ V2, was judged as accelerated motion, the instruction of motor capacity is switched to " in ".In addition, in the switching of motor capacity instruction, hysteresis is arranged, when vehicle speed deviation Δ V reduces, before vehicle speed deviation Δ V reaches the first value Δ V1, the instruction of motor capacity be " in ", when vehicle speed deviation Δ V is worth Δ V1 less than first, being judged as accelerated motion and finishing, the instruction of motor capacity is switched to " little ".

When the instruction of motor capacity is switched to " in " time, with the step S144 of Fig. 6 in the same manner, driving signal (the motor capacity command signal that output and electromagnetic proportional valve 81 are corresponding; Voltage signal) Em.Thus, when the instruction of motor capacity is switched to " in " time, the capacity of hydraulic traveling motor 14 be increased to " in ", when the instruction of motor capacity was switched to " little ", the capacity of hydraulic traveling motor 14 reduced to " little ".

In above such present embodiment that consists of, also can access the effect identical with the first mode of execution.

With Figure 18～Figure 20 another embodiment of the present invention is described.About present embodiment, the action operating condition in addition of going up a slope is identical with the first mode of execution, control motor capacity and pump duty with judgement selection function shown in Figure 5, when going up a slope action, only use the head pressure (pump pressure) of oil hydraulic pump 10 to control motor capacity and pump duty.

At first, the pump duty control in the upward slope action that utilizes pump pressure is described.In the present embodiment, also be to carry out pump duty control by the maximum speed that changes motor.

Figure 18 shows and has assembled the functional block diagram that is used for utilizing pump pressure overview of the engine control operational part of the function of control pump duty when going up a slope action.Among the figure, to the identical reference character of parts mark that is equal to parts shown in Figure 9.

Engine control operational part in the present embodiment also has each function of upward slope incremental speed operational part 95A and upward slope rotating speed of target correction portion 96A on the basis of each function with the rotating speed of target operational part 90 that travels shown in Figure 9, operative goals rotating speed operational part 91, datum target rotating speed operational part 92, switching part 97, maximum selection rule section 98, rotating speed of target correction portion 99.

Upward slope incremental speed operational part 95A calculates with head pressure (pump pressure) Pp by pressure transducer 73 detected oil hydraulic pumps 10 and goes up a slope accordingly with revising incremental speed Δ Ns, upward slope rotating speed of target correction portion 96A revises this increment Delta Ns with travelling rotating speed of target Nt addition, and exports the rotating speed of target Nt1 that travels

Figure 18 shows the pump pressure Pp that sets and the figure that goes up a slope with the relation of revising incremental speed Δ Ns in upward slope incremental speed operational part 95A.Before head pressure (pump pressure) Pp of oil hydraulic pump 10 reaches the first value Pa, engine speed increment Delta Ns is zero, when pump pressure Pp surpasses the first value Pa, be judged as the action of going up a slope, the increase of increment Delta Ns and pump pressure Pp increases pro rata rapidly, when pump pressure Pp surpassed the second value Pb, increment Delta Ns was maximum value Δ Nsmax.

As described above, in upward slope rotating speed of target correction portion 96A, with increment Delta Ns and the rotating speed of target Nt addition of travelling, correspondingly, final rotating speed of target Nf3 increases.Thus, with the first mode of execution in the same manner, when output increment Δ Ns, the maximum speed of motor 1 rises to Ntmax2 from Ntmax1, the maximum discharge flow rate of oil hydraulic pump 10 is increased to Qmax2 from Qmax1, when the output of increment Delta Ns stopped, the maximum speed of motor 1 was got back to Ntmax1, and the maximum discharge flow rate of oil hydraulic pump 10 reduces to Qmax2.

The below describes the motor volume controlled in the upward slope action that has utilized pump pressure.

Figure 20 shows the figure of the relation of pump pressure Pp and the instruction of motor capacity.Before pump pressure Pp arrived the second value Pb, the instruction of motor capacity was " little ", when pump pressure Pp surpasses the second value Pb, was judged as the action of going up a slope, the instruction of motor capacity is switched to " in ".In addition, in the switching of motor capacity instruction, hysteresis is arranged, when pump pressure Pp descends, before pump pressure Pp arrives the first value Pa, the instruction of motor capacity be " in ", when pump pressure Pp is worth Pa less than first, be judged as the upward slope release, the instruction of motor capacity is switched to " little ".

When the instruction of motor capacity is switched to " in " time, with the step S144 of Fig. 6 in the same manner, driving signal (the motor capacity command signal that output and electromagnetic proportional valve 81 are corresponding; Voltage signal) Em.Thus, when the instruction of motor capacity is switched to " in " time, the capacity of hydraulic traveling motor 14 be increased to " in ", when the instruction of motor capacity was switched to " little ", the capacity of hydraulic traveling motor 14 reduced to " little ".

In above such present embodiment that consists of, also can access the effect identical with the first mode of execution.

Several mode of execution of the present invention more than has been described, these mode of executions can carry out various distortion in the scope of technological thought of the present invention.

For example, in the above-described embodiment, to open loop-type the oil hydraulic circuit of connecting fluid press pump 10 with the driving system of hydraulic traveling motor 14 is illustrated, but the hydraulic system of travelling of loop circuit formula also can be with identical structure applications the present invention.

In addition, in the above-described embodiment, increase the capacity of hydraulic traveling motor 14 according to external command, but the speed changer of speed changer 15 grades that also can be by switching driving system increases to increase the equivalent capacity (equivalent capacity that comprises the driving system of hydraulic traveling motor 14) that recently makes driving system that slows down, and so also can access identical effect.

In addition, in the above-described embodiment, increase pump duty by the rotating speed that increases motor 1, and increase the peak rate of flow (flow travels) of driving system, if but the oil hydraulic pump that uses has more than neededly, and also can be the structure that the maximum capacity of oil hydraulic pump is increased.In addition, in the vehicle of the driving system with loop-type, use in the situation of the sensor-type direction switch valve of road, can also switch by switching LS pressure reduction (the front and back pressure reduction of direction switch valve) peak rate of flow of driving system.

Further, also can use a plurality of oil hydraulic pumps, and make in their situation of discharge oil interflow with acquisition peak rate of flow (flow travels), switch the quantity of the oil hydraulic pump at interflow.

In addition, by the capacity of having or not of switching recently according to the deceleration of speed changer that control of the present invention in each velocity stage implements or hydraulic traveling motor, can improve the rideability of vehicle.

For example in having the vehicle of three-range transmission, in 3 speed that capacity significantly reduces, use control of the present invention, and the capacity of the hydraulic traveling motor after will switching is set greatlyr.Can guarantee enough hydraulic braking force thus.On the contrary, in 1 speed that equivalent capacity becomes enough large, by ending the application of control of the present invention, braking force significantly becomes large and greater impact occurs when causing deceleration-operation in the time of can avoiding slowing down.

In addition, 2 speed in the middle of be arranged in by using control of the present invention, and make motor Capacity Ratio 3 speed after the switching little, the sensation in the time of can guaranteeing enough braking force and good deceleration.

In addition, in the above-described embodiment, the situation of the direction switch valve of hydraulic pilot formula is illustrated, but also can be applied to utilize electric bar with the vehicle of the Flight By Wire formula of controller function direction switch valve.

Moreover, in the above-described embodiment, to only being illustrated at the example that drives use oil hydraulic pump 10 in the loop that travels, but driven by the direction switch valve of multiple linked in the situation of the final controlling element beyond travelling, also can implement best the present invention by judge travel single movement or composition operation according to the operation signal of pump pressure and other final controlling element.

Claims (21)

1. the travel controlling system of a hydraulic traveling vehicle, comprise the oil hydraulic pump (10) that is driven by prime mover (1), the hydraulic traveling motor (14) of the variable capacity type that is driven by the hydraulic oil of supplying with from this oil hydraulic pump, be arranged on the direction switch valve (12) between described oil hydraulic pump and the described hydraulic traveling motor, the speed changer (15) that arranges at the carry-out part of described hydraulic traveling motor (14), with the wheel (108) that is driven by described hydraulic traveling motor (14) via described speed changer (15), it is characterized in that, comprising:

The a plurality of parameters relevant with the travelling state of described hydraulic traveling vehicle detect in feeler mechanism (71,72,73,73);

Travelling state decision mechanism (80, S100, S120) is judged the travelling state of described hydraulic traveling vehicle based on a plurality of parameters relevant with described travelling state; And

Control mechanism (33,80, S 130～S 150,81,82), control from described oil hydraulic pump via the peak rate of flow and the equivalent capacity that comprise the driving system of described hydraulic traveling motor and described speed changer of described direction switch valve to the hydraulic oil of described hydraulic traveling motor (14) supply according to the judged result of described travelling state

Described control mechanism is controlled the equivalent capacity of the driving system that comprises described hydraulic traveling motor and described speed changer by the capacity of the described hydraulic traveling motor of control (14) and any one in the reduction speed ratio of described speed changer (15).

2. the travel controlling system of hydraulic traveling vehicle as claimed in claim 1 is characterized in that,

Described control mechanism (33,80, S130～S150,81,82) is controlled the equivalent capacity of the driving system that comprises described hydraulic traveling motor by the capacity of the described hydraulic traveling motor of control (14).

3. the travel controlling system of hydraulic traveling vehicle as claimed in claim 1 is characterized in that,

Described control mechanism is recently controlled the equivalent capacity of the driving system that comprises described hydraulic traveling motor by the deceleration of switching described speed changer.

4. the travel controlling system of hydraulic traveling vehicle as claimed in claim 1 is characterized in that,

The rotating speed of described control mechanism (33,80, S130～S150,81,82) by described prime mover of control (1) controlled the peak rate of flow that described hydraulic traveling motor (14) is supplied with thus to increase and decrease the discharge flow rate of described oil hydraulic pump (10).

5. the travel controlling system of hydraulic traveling vehicle as claimed in claim 1 is characterized in that,

The maximum capacity of described control mechanism by the described oil hydraulic pump of control (10) controlled the peak rate of flow that described hydraulic traveling motor (14) is supplied with thus to increase and decrease the discharge flow rate of described oil hydraulic pump.

6. the travel controlling system of hydraulic traveling vehicle as claimed in claim 1 is characterized in that,

The peak rate of flow that described control mechanism is supplied with described hydraulic traveling motor by described direction switch valve control.

7. the travel controlling system of hydraulic traveling vehicle as claimed in claim 1 is characterized in that,

Described travelling state decision mechanism (80, S100, S120) judges whether described travelling state is at least usually some in travelling state and the descending state,

When described travelling state is in described common travelling state, described control mechanism (33,80, S130～S150,81,82) is controlled, so that the peak rate of flow that described hydraulic traveling motor (14) is supplied with is predefined first flow, and the equivalent capacity that makes the driving system that comprises described hydraulic traveling motor is for guaranteeing the equivalent capacity of the predefined maximum speed of travelling, i.e. the first capacity under described first flow; When described travelling state is in described descending state, described control mechanism (33,80, S130～S150,81,82) is controlled, so that the equivalent capacity of driving system that comprises described hydraulic traveling motor is for than described first the second capacity capacious, and make the peak rate of flow that described hydraulic traveling motor is supplied with for can under described the second capacity, guaranteeing the second flow of described predefined maximum speed.

8. the travel controlling system of hydraulic traveling vehicle as claimed in claim 1 is characterized in that,

Described travelling state decision mechanism (80, S100, S120) judges whether described travelling state is at least usually some in travelling state and the acceleration mode,

When described travelling state is in described common travelling state, described control mechanism (33,80, S130～S150,81,82) is controlled, so that the peak rate of flow that described hydraulic traveling motor (140) is supplied with is first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be the first capacity; When described travelling state is in described acceleration mode, described control mechanism (33,80, S130～S150,81,82) is controlled, so that the peak rate of flow that described hydraulic traveling motor is supplied be second flow larger than described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be than first the second capacity capacious.

9. the travel controlling system of hydraulic traveling vehicle as claimed in claim 1 is characterized in that,

Described travelling state decision mechanism (80, S100, S120) judges whether described travelling state is at least usually some in travelling state and the upward slope state,

When described travelling state is in described common travelling state, described control mechanism (33,80, S130～S150,81,82) is controlled, so that the peak rate of flow that described hydraulic traveling motor (14) is supplied with is first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be the first capacity; When described travelling state is in described upward slope state, described control mechanism (33,80, S130～S150,81,82) is controlled, so that the peak rate of flow that described hydraulic traveling motor is supplied be second flow larger than described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be than first the second capacity capacious.

10. such as the travel controlling system of each described hydraulic traveling vehicle in the claim 7 to 9, it is characterized in that,

Described travelling state decision mechanism (80, S100, S120) judges also whether described travelling state is in deceleration regime,

When described travelling state is in described deceleration regime, described control mechanism (33,80, S130～S150,81,82) is controlled, so that the peak rate of flow that described hydraulic traveling motor (14) is supplied with is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the second capacity.

11. the travel controlling system of hydraulic traveling vehicle as claimed in claim 1 is characterized in that,

Described control mechanism has the first control mechanism (80, S120, S130, S150,82,99) and the second control mechanism (33,80, S120, S130, S140,81), described the first control mechanism (80, S120, S130, S150,82,99) is according to the judged result of described travelling state, and the control of the maximum speed by increasing and decreasing described prime mover (1) is controlled at first flow with the maximum discharge flow rate of described oil hydraulic pump (10) and at least than between the second large flow of this first flow; Described the second control mechanism (33,80, S120, S130, S140,81) is according to the judged result of described travelling state, the equivalent capacity that will comprise the driving system of described hydraulic traveling motor (14) is controlled at least the first capacity and than between this first second capacity capacious

The second flow of described oil hydraulic pump and the second capacity of described driving system are set, so that when the equivalent capacity of the driving system that will comprise described hydraulic traveling motor is controlled at the second capacity, vehicle adapts to set travel the second flow of needed flow and described oil hydraulic pump of maximum speed.

12. the travel controlling system of hydraulic traveling vehicle as claimed in claim 11 is characterized in that,

Described control gear is also set the first flow of described oil hydraulic pump and the first capacity of described driving system, so that when the equivalent capacity of the driving system that will comprise described hydraulic traveling motor (14) is controlled at described the first capacity, vehicle adapts with the travel first flow of needed flow and described oil hydraulic pump (10) of described setting maximum speed.

13. the travel controlling system such as claim 11 or 12 described hydraulic traveling vehicles is characterized in that,

Described the second control mechanism (33,80, S120, S130, S140,81) is controlled the equivalent capacity of the driving system that comprises described hydraulic traveling motor by the capacity of controlling described hydraulic traveling motor.

14. the travel controlling system such as claim 11 or 12 described hydraulic traveling vehicles is characterized in that,

Described the second control mechanism is recently controlled the equivalent capacity of the driving system that comprises described hydraulic traveling motor by the deceleration of switching described speed changer.

15. the travel controlling system such as claim 11 or 12 described hydraulic traveling vehicles is characterized in that,

Described travelling state decision mechanism (80, S100, S120) judges whether described travelling state is at least usually some in travelling state and the descending state,

When described travelling state is in described common travelling state, described the first control mechanism (80, S120, S130, S150,82,99) and the second control mechanism (33,80, S120, S130, S140,81) are controlled, so that the discharge flow rate of described oil hydraulic pump (10) is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor (14) be described the first capacity; When described travelling state is in described descending state, described the first control mechanism (80, S120, S130, S150,82,99) and the second control mechanism (33,80, S120, S130, S140,81) are controlled, so that the discharge flow rate of described oil hydraulic pump is described the second flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the second capacity.

16. the travel controlling system such as claim 11 or 12 described hydraulic traveling vehicles is characterized in that,

Described travelling state decision mechanism (80, S100, S120) judges whether described travelling state is at least usually some in travelling state and the acceleration mode,

When described travelling state is in described common travelling state, described the first control mechanism (80, S120, S130, S150,82,99) and the second control mechanism (33,80, S120, S130, S140,81) are controlled, so that the discharge flow rate of described oil hydraulic pump (10) is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor (14) be described the first capacity; When described travelling state is in described acceleration mode, described the first control mechanism (80, S120, S130, S150,82,99) and the second control mechanism (33,80, S120, S130, S140,81) are controlled, so that the discharge flow rate of described oil hydraulic pump is described the second flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the second capacity.

17. the travel controlling system such as claim 11 or 12 described hydraulic traveling vehicles is characterized in that,

Described travelling state decision mechanism (80, S100, S120) judges whether described travelling state is at least usually some in travelling state and the upward slope state,

When described travelling state is in described common travelling state, described the first control mechanism (80, S120, S130, S150,82,99) and the second control mechanism (33,80, S120, S130, S140,81) are controlled, so that the discharge flow rate of described oil hydraulic pump (10) is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor (14) be described the first capacity; When described travelling state is in described upward slope state, described the first control mechanism (80, S120, S130, S150,82,99) and the second control mechanism (33,80, S120, S130, S140,81) are controlled, so that the discharge flow rate of described oil hydraulic pump is described the second flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor be described the second capacity.

18. the travel controlling system of hydraulic traveling vehicle as claimed in claim 15 is characterized in that,

Described travelling state decision mechanism (80, S100, S120) judges also whether described travelling state is in deceleration regime,

When described travelling state is in described deceleration regime, described the first control mechanism (80, S120, S130, S150,82,99) and the second control mechanism (33,80, S120, S130, S140,81) are controlled, so that the discharge flow rate of described oil hydraulic pump (10) is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor (14) be described the second capacity.

19. the travel controlling system of hydraulic traveling vehicle as claimed in claim 16 is characterized in that,

Described travelling state decision mechanism (80, S100, S120) judges also whether described travelling state is in deceleration regime,

When described travelling state is in described deceleration regime, described the first control mechanism (80, S120, S130, S150,82,99) and the second control mechanism (33,80, S120, S130, S140,81) are controlled, so that the discharge flow rate of described oil hydraulic pump (10) is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor (14) be described the second capacity.

20. the travel controlling system of hydraulic traveling vehicle as claimed in claim 17 is characterized in that,

Described travelling state decision mechanism (80, S100, S120) judges also whether described travelling state is in deceleration regime,

When described travelling state is in described deceleration regime, described the first control mechanism (80, S120, S130, S150,82,99) and the second control mechanism (33,80, S120, S130, S140,81) are controlled, so that the discharge flow rate of described oil hydraulic pump (10) is described first flow, and to make the equivalent capacity of the driving system that comprises described hydraulic traveling motor (14) be described the second capacity.

21. the travel controlling system of hydraulic traveling vehicle as claimed in claim 1 is characterized in that,

As a plurality of parameters relevant with the travelling state of described hydraulic traveling vehicle, described feeler mechanism (71,72,73,74) detect at least described hydraulic traveling vehicle travelling speed, be used for driving the mobility operation instruction of described hydraulic traveling motor (14) and the head pressure of described oil hydraulic pump (10).

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