CN100519399C - Drive control apparatus for forklift - Google Patents

Abstract

A load determining section (54) of a drive control apparatus (52, 53) for forklift (10) determines a load state related to a loading attachment (22). In a case where a connection determining section (54, S20) determines switching to a connection state, if the load state determined by the load determining section (54, S10) requires that driving of a vehicle body (11) be limited, a disconnection control section (54, S25) forcibly disconnects a transmission of a driving force to a drive wheel (14). Thus, the forklift (10) is prevented from being started in a state that is likely to make the driving of the forklift unstable.

Description

The drive control apparatus that is used for fork truck

Art

The present invention relates to be used to control the drive control apparatus that fork truck drives.

Background technology

Usually, in factory, fork truck is widely used as industrial vehicle with operation load (lifting and place load).Because its specific application, the driving change of stability of this class fork truck greatly depends on load condition.For example, at bearing load not with carry between the load, the center of gravity of vehicle changes, and it is variant to drive stability.When carrying load, drive the angle of inclination of height that stability depends on the car fork of load weight, support loads, car fork and change.Therefore, usually, the technology that has disclosed a kind of driving that limits fork truck according to load condition in the file of Japanese patent application publication No. No.2001-163597 is to improve the driving stability of vehicle.In the file of publication number No.2001-163597, calculate the minimum acceleration value that causes trailing wheel to lift when the vehicle rollback based on load condition, and this value is set to admissible acceleration/accel from ground.The actual acceleration of vehicle is restricted to and is no more than described admissible acceleration/accel.

Disclosed a kind of for example driving of rice transplanter, combination machine and trac. pulsation-free technology that becomes of vehicle that is used to make in the Japanese patent application publication No. No.9-24751 file.A kind of technology is proposed in the Japanese patent application publication No. No.9-24751 file, when rice transplanter is finished rice transplanting and is begun on the way to drive, by master clutch is switched to engagement state from released state, engine speed is lowered to predetermined engine speed.

The technology that discloses among the Japanese patent application publication No. No.2001-163597 is based on the vehicle unsettled fact that becomes in accelerator, the degree that restriction is quickened.In the flat-out acceleration of vehicle, the disclosed technology that is used to limit acceleration/accel can not prevent that vehicle from becoming unstable among the publication number No.2001-163597.In other words, be under the situation of released state for the power-transfer clutch of drive wheel the transmission of power of driving engine or drive source, and be used to instruct the direction lever of vehicle direct of travel to be under the situation of Neutral Position, if the operation acceleration pedal, engine speed rises but vehicle is quickened so.In this state, if clutch engagement or direction lever are placed in activation point, acceleration/accel meeting flip-flop and vehicle are by flat-out acceleration so.Therefore, in the Acceleration Control that discloses in Japanese patent application publication No. No.2001-163597, engine control is not in time carried out to handle the unexpected variation of this acceleration/accel.As a result, vehicle is by fly start, the driving instability when this may cause vehicle launch.

On the contrary, in Japanese patent application publication No. No.9-24751 file, when master clutch when released state switches to engagement state, engine speed is reduced temporarily, thereby has avoided fly start.Yet for example in the fork truck, the driving stability of vehicle changes according to load condition at the industrial vehicle of bearing load.Therefore, even the control that discloses among the Japanese patent application publication No. No.9-24751 is applied to fork truck, the driving stability during starting still can not guarantee fully.In other words, even carry out the control that engine speed reduces when clutch engagement, the joint of power-transfer clutch also allows propulsive effort to be passed on the drive wheel.Therefore vehicle is advanced.Thereby, in driving the stable fork truck that changes according to load condition, under the situation of relatively low position,, engine speed needs the regular hour even descending at load-bearing, and described stability also can be guaranteed.Yet under the relatively harsh situation of load-up condition, for example, when load-bearing during in higher relatively position, described stability may not guarantee.As a result, according to load condition, the decline of engine speed can not enough be performed (engine control is early not enough) early.Driving instability when this makes starting.

Summary of the invention

Therefore, one object of the present invention is to provide a kind of drive control apparatus that is used for fork truck, prevents that fork truck from being started may making under the driving unsure state of fork truck.

In order to realize aforementioned purpose, and according to an aspect of the present invention, provide a kind of drive control apparatus that is used for fork truck.Described fork truck comprises car body, the drive wheel on the car body, driving engine, is arranged in the Poewr transmission mechanism between driving engine and the drive wheel and is positioned at Vehicular body front and the bogey of bearing load.Poewr transmission mechanism can switch engine power being passed to the coupled condition of drive wheel and the transmission of power of driving engine is not given between the off-state of drive wheel.Fork truck utilizes the power of driving engine to advance as propulsive effort.Drive control apparatus comprises and connects determining section, load determining section and disconnect control part.Connect the operation that determining section determines whether Poewr transmission mechanism responds chaufeur and switch to coupled condition from off-state.The load determining section is determined the load condition relevant with bogey.Determine to switch under the situation of coupled condition connecting determining section,, disconnect control part so and force to disconnect the transmission of propulsive effort to drive wheel if the load condition of being determined by the load determining section need limit the driving of car body.

According to another aspect of the present invention, provide a kind of drive control apparatus that is used for fork truck.Described fork truck comprises car body, the drive wheel on the car body, driving engine, is arranged in the Poewr transmission mechanism between driving engine and the drive wheel and is positioned at Vehicular body front and the bogey of bearing load.Poewr transmission mechanism can switch engine power being passed to the coupled condition of drive wheel and the transmission of power of driving engine is not given between the off-state of drive wheel.Fork truck utilizes the power of driving engine to advance as propulsive effort.Drive control apparatus comprises and connects determining section, engine speed determining section and disconnect control part.Connect the operation that determining section determines whether Poewr transmission mechanism responds chaufeur and switch to coupled condition from off-state.The engine speed determining section is determined the rotating speed of driving engine.Limit engine speed is set to the speed without load that is higher than driving engine at least.Determine to switch under the situation of coupled condition in the connection determining section,, disconnect control part so and force to disconnect the transmission of propulsive effort to drive wheel if the engine speed of being determined by the engine speed determining section is equal to or greater than limit engine speed.

By description taken together with the accompanying drawings hereinafter, other aspects and advantages of the present invention will become obviously, and these accompanying drawings are described by principle of the present invention is added by way of example.

Description of drawings

The present invention and purpose thereof and advantage hereinafter will be able to best understanding to the description of currently preferred embodiment in conjunction with the accompanying drawings by reference, and wherein these accompanying drawings are:

Fig. 1 is the lateral plan of fork truck;

Fig. 2 is the scheme drawing that shows forward relay circuit and reverse relay circuit, and they lay respectively at vehicle control apparatus and advance between the electromagnetic valve and controller of vehicle and retreating between the electromagnetic valve;

Fig. 3 is the scheme drawing of fork truck;

Fig. 4 shows the restricted areas of the vehicle that defines according to loading condition and the graph of a relation in unrestricted zone;

Fig. 5 shows the graph of a relation that concerns between loading condition and the max speed value;

Fig. 6 shows the graph of a relation that concerns between loading condition and the acceleration/deceleration value;

Fig. 7 is the diagram of circuit that shows the restriction deterministic process;

Fig. 8 is the diagram of circuit that shows according to the start-up restriction process of first embodiment;

Fig. 9 is the diagram of circuit that shows the engine retard process of carrying out as the subprogram of the start-up restriction process shown in Fig. 8;

Figure 10 shows the graph of a relation that concerns between engine speed regulated quantity, speed of a motor vehicle difference and the acceleration/deceleration grade;

Figure 11 is the diagram of circuit that shows according to the start-up restriction process of second embodiment;

Figure 12 is the diagrammatic view of explanation according to the structure of the fork truck of the 3rd embodiment;

Figure 13 shows the graph of a relation that concerns between clutch pressure and the slow-action pedal depression amount;

Figure 14 (a) is to show the graph of a relation that concerns between acceleration pedal depression amount, slow-action pedal depression amount, engine speed and the speed of a motor vehicle to 14 (d);

Figure 15 is the diagram of circuit that shows according to the starting control process of the 4th embodiment;

Figure 16 is the diagram of circuit that shows according to the starting control process of the 5th embodiment;

Figure 17 is presented under the situation that the control according to the 7th embodiment is not performed the graph of a relation that concerns between the speed of a motor vehicle and the engine speed;

Figure 18 is presented under the situation that the control according to the 7th embodiment is not performed the graph of a relation that concerns between the speed of a motor vehicle and the engine speed;

Figure 19 is the diagram of circuit that shows according to the starting control process of the 7th embodiment;

Figure 20 shows the graph of a relation that concerns between the speed of a motor vehicle and the engine speed, has shown the operation of the 7th embodiment;

Figure 21 is the diagram of circuit that shows according to the starting control process of the 8th embodiment;

Figure 22 shows the graph of a relation that concerns between the speed of a motor vehicle and the engine speed, has shown the operation on mild sloping road according to the 8th embodiment; And

Figure 23 shows the graph of a relation that concerns between the speed of a motor vehicle and the engine speed, has shown the operation on precipitous sloping road according to the 8th embodiment.

The specific embodiment

Below with reference to the drive control apparatus CD that be used for fork truck 10 of accompanying drawing 1 to 9 description according to first embodiment of the invention.Hereinafter, the direction faced of the chaufeur of fork truck 10 is defined as the place ahead.Rear, top, below, left and right-handly define with reference to the place ahead.

Fig. 1 is the lateral plan of fork truck 10.As shown in fig. 1, fork truck 10 comprises the bogey 12 that is positioned at car body 11 front portions.Operator's compartment 13 is formed in the centre portion of car body 11.Drive wheel (front-wheel) 14 is positioned at the front lower place of car body 11, and wheel flutter 15 is positioned at the back lower place of car body 11.Car body 11 also is equipped with the change-speed box 18 with tor-con 17.Tor-con 17 forms Power train.Driving engine 16 links to each other with drive wheel 14 by the change-speed box 18 with tor-con 17.Change-speed box 18 is between drive wheel 14 and driving engine 16.Fork truck 10 in the present embodiment belongs to engine type (engine vehicle), and wherein drive wheel 14 is driven by driving engine 16.In other words, fork truck 10 is advanced by means of the power of driving engine 16.

Bogey 12 is then described.Multistage (being two-stage in the present embodiment) strut assemblies 19 is positioned at the front portion of car body 11.This strut assemblies 19 comprises an a pair of left side and right outer leg 20 and an a pair of left side and Right Inboard pillar 21.An a pair of left side is pitched (carrier member) with right car and is linked to each other with strut assemblies 19 by means of shears 23.Hydraulic tilting cylinder 24 links to each other with each outer leg 20 so that strut assemblies 19 (car fork 22) having upwardly sloped front and rear sides at car body 11.Hydraulic lifting cylinder 25 links to each other with each inboard pillar 21.Lift cylinders 25 promotes with respect to car body or falls car and pitch 22.

The driver's seat 26 that chaufeur is taken is positioned at operator's compartment 13.And instrument carrier panel 27 is positioned at operator's compartment 13 front portions.Have steering handwheel 28, descending operation bar 29, tilt operation bar 30 and driving command part on instrument carrier panel 27, described driving command partly is a forward/back control lever (direction control stalk) 31.Steering handwheel 28 is used to change the steering angle of wheel flutter 15.Operate lifting control lever 29 is with lifting or fall car fork 22, and handles tilt operation bar 30 so that strut assemblies 19 tilts.When operate lifting control lever 29, lift cylinders 25 is driven according to steering (direction of improvement or descent direction), thereby makes inboard pillar 21 slide along outer leg 20.Therefore, car fork 22 is raised or falls.When handling tilt operation bar 30, inclined cylinder 24 is driven (stretch out or withdraw) according to steering (direction that turns forward or the direction that recedes), thereby makes strut assemblies 19 be with car fork 22 inclinations together.Handle the direct of travel (in the present embodiment, be working direction or direction of retreat) of forward/back control lever 31 with control vehicle.

The floor of operator's compartment 13 is provided with the vehicle accelerating part, and it is an acceleration pedal 32; The slow-action function part, it is a slow-action pedal 33; And the brake operating part, it is a brake pedal 34.Fig. 1 has shown acceleration pedal 32 and slow-action pedal 33.Fig. 3 has shown brake pedal 34.Handle the acceleration (driving) of acceleration pedal 32 with control vehicle.Handle slow-action pedal 33 with when manually-operated vehicle in loading process is slowly advanced, the power-transfer clutch (forward clutch 42 and back clutch 43) of change-speed box 18 is partly engaged.Under the effect of slow-action pedal 33, the engagement state of power-transfer clutch (forward clutch 42 and back clutch 43) changes continuously at joint with between separating.Brake activation pedal 34 thinks that vehicle provides braking force.When operation, brake pedal 34 is operated in the mode that is independent of slow-action pedal 33.On the other hand, when operational stroke is more than half, 33 beginnings and brake pedal 34 interlockings of slow-action pedal.In other words, slow-action pedal 33 is operated (no interlocking) in the mode that is independent of brake pedal 34 in the slow-action zone, and (brake area) and brake pedal 34 interlockings outside the slow-action zone.The slow-action zone refers to a zone, and slow-action pedal 33 is operated and power-transfer clutch (forward clutch 42 and back clutch 43) partly engages in this zone.Brake area is a zone, is applied on the vehicle in this zone inside brake power.

Fig. 3 is a diagrammatic view, shows the fork truck 10 of current embodiment.

The output shaft 16a of driving engine 16 is connected on the change-speed box 18 with tor-con 17.Driving engine 16 has throttle valve drive device 35.Handle described throttle valve drive device 35 to regulate the damper aperture.Therefore, the speed of driving engine 16, promptly the speed of output shaft 16a is conditioned.Driving engine 16 also links to each other with the loading pump with accelerating gear 37, and described loading pump is a Hydraulic Pump 36.Hydraulic Pump 36 launched machines 16 drive.In the fork truck 10 of current embodiment, the power of driving engine 16 is used for powered vehicle and advances and be used to drive bogey 12 (inclined cylinder 24 and lift cylinders 25).The discharge side of Hydraulic Pump 36 links to each other with inclined cylinder 24 so that strut assemblies 19 (car fork 22) tilts, and also links to each other with lift cylinders 25 to promote and to fall car and pitch 22.Inclined cylinder 24 is connected on the Hydraulic Pump 36 by conduit and car fork inclination solenoid electric valve 38, and lift cylinders 25 is connected on the Hydraulic Pump by conduit and car fork lifting/lowering solenoid electric valve 39.

Change-speed box 18 has input shaft (main shaft) 40 and output shaft (countershaft) 41.Input shaft 40 is connected on forward clutch 42 and the back clutch 43.Forward clutch 42 and back clutch 43 are hydraulic clutch (in the present embodiment, being multi-disc wet clutch).Forward clutch 42 and back clutch 43 have pressure receiving cavity 42a, 43a respectively.The engaging force of each power- transfer clutch 42,43 is regulated (hereinafter, being called clutch pressure) by the hydraulic coupling in relevant pressure reception cavity 42a, the 43a.When clutch pressure increased, engaging force reduced.

Forward clutch 42 links to each other with the electromagnetic valve 44 that advances, and back clutch 43 with retreat electromagnetic valve 45 and link to each other.Electromagnetic valve 44 links to each other with Hydraulic Pump 46 by conduit with 45.When driving engine 16 runnings, Hydraulic Pump 46 drives (turning force of the input shaft 40 of change-speed box 18) by the turning force that passes to change-speed box 18.The operation of Hydraulic Pump 46 provides hydraulic oil by the march forward pressure receiving cavity 42a of power-transfer clutch 42 of the electromagnetic valve 44 that advances.Similar, the operation of Hydraulic Pump 46 provides hydraulic oil by retreating the draw back pressure receiving cavity 43a of power-transfer clutch 43 of electromagnetic valve 45.In the present embodiment, when electric current in the screw actuator is zero, the electromagnetic valve 44 and retreat electromagnetic valve 45 standard-sized sheets of advancing, and when electric current feeds screw actuator, both full cut-offs.When leading to the solenoidal electric current vanishing of electromagnetic valve 44,45, hydraulic oil feeds to pressure receiving cavity 42a, 43a, and forward clutch 42 separates with back clutch 43.When electric current feeds the screw actuator of electromagnetic valve 44,45, there is not hydraulic oil to feed to pressure receiving cavity 42a, 43a, and forward clutch 42 and back clutch 43 joints.

Forward gear messenger chain 47 links to each other with the output shaft 41 of change-speed box 18 with backward gear messenger chain 48. Gear transmission chain 47,48 rotations with input shaft 40 pass to output shaft 41.The output shaft 41 of change-speed box 18 is connected on the vehicle bridge 50 with diff 49.Drive wheel 14 is positioned at vehicle bridge 50 two ends.The power of driving engine 16 passes to vehicle bridge 50 by the output shaft 41 of change-speed box 18, and drive wheel 14 with the corresponding direction of the hand of rotation of output shaft 41 on rotate.Each drive wheel 14 all is equipped with hydraulic drum brake 51.

Although tor-con 17, change-speed box 18, the electromagnetic valve 44 that advances, retreat electromagnetic valve 45 and Hydraulic Pump 46 illustrates separately in Fig. 3, yet these parts all are contained in the housing.

Car body 11 is equipped with vehicle control apparatus 52 and device for controlling engine 53.In the present embodiment, vehicle control apparatus 52 and device for controlling engine 53 form the driving of drive control apparatus CD (shown in broken lines in Fig. 3) with control fork truck 10.Vehicle control apparatus 52 and device for controlling engine 53 interconnect, thereby make electric signal to transmit between equipment 52,53.Vehicle control apparatus 52 and device for controlling engine 53 can adopt wired connection or wireless connections.Vehicle control apparatus 52 has the central processing unit (CPU) 54 that is used for control vehicle, is used for the random access memory 55 and the input-output interface 56 of control vehicle.Memory device 55 stores driving and the cargo-carring program that is used to control fork truck 10.Memory device 55 also stores driving and the cargo-carring mapping (enum) data (being presented at Fig. 4,5 and 6) that is used for controlling fork truck 10.Device for controlling engine 53 has the central processing unit (CPU) 57 that is used to control driving engine 16, random access memory 58 and the input-output interface 59 that is used to control driving engine 16.Memory device 58 stores the program that is used to control driving engine 16.Memory device 58 also stores the mapping (enum) data (being presented at Figure 10) that is used for controlling driving engine 16.Vehicle control apparatus 52 inputs come from the detection signal of all kinds sensor and come from various types of signals of device for controlling engine 53, and the driving and the loading of control fork truck 10.Device for controlling engine 53 inputs come from the detection signal of all kinds sensor and come from various types of signals of vehicle control apparatus 52, and control driving engine 16.

As shown in Figure 2, vehicle control apparatus 52 is connected on the electromagnetic valve 44 that advances by forward relay circuit 60, and is connected to by reverse relay circuit 61 and retreats on the electromagnetic valve 45.Forward relay circuit 60 is formed by the normally closed contactor that advances (contactless switch b) 60a and forward relay coil (electromagnetism) 60b.By making 60b demagnetization of forward relay coil and the closure normally closed contactor 60a that advances, electromagnetic valve 44 energisings of advancing.Reverse relay circuit 61 is by retreating normally closed contactor (contactless switch b) 61a and reverse relay coil (electromagnetism) 61b forms.By making 61b demagnetization of reverse relay coil and closure retreat normally closed contactor 61a, retreat electromagnetic valve 45 energisings.

Below, description is installed in be connected (the sensor institute bonded assembly device) of various sensors on the fork truck 10 and sensor.

Driving engine 16 has the engine speed sensor 62 that is used for detection of engine 16 rotating speeds.Engine speed sensor 62 is connected on the device for controlling engine 53, and output and engine speed relevant detection signal (engine rotational speed signal).The vehicle speed sensor 63 that is used to detect fork truck 10 car speeds be positioned at car body 11 with drive wheel 14 corresponding positions.Vehicle speed sensor 63 is connected on the device for controlling engine 53, and each one of sensor output and car speed relevant detection signal (vehicle velocity signal).The detection signal of engine speed sensor 62 and vehicle speed sensor 63 is transferred to vehicle control apparatus 52 from device for controlling engine 53.

Strut assemblies 19 has the height sensor 64 that is used for inspection vehicle fork 22 height.Height sensor 64 is connected on the vehicle control apparatus 52.When car fork 22 reaches predetermined altitude H (for example 2200mm), height sensor 64 output detection signals (altitude signal).Height sensor 64 is for example formed by limit switch.In the present embodiment, strut assemblies 19 has single height sensor 64.The scope that is equal to or higher than the height H that is recorded by height sensor 64 is defined as the high altitude scope, and the scope that is lower than height H is defined as the low clearance scope.

The gradient sensor 65 that is used for detecting the angle of inclination is assemblied in of inclined cylinder 24.Gradient sensor 65 links to each other with vehicle control apparatus 52, and inspection vehicle fork 22 is in the angle of inclination of the angle (grade angle) at rank position place with respect to car fork 22.Gradient sensor 65 outputs and angle of inclination relevant detection signal (inclination angle signal).Gradient sensor 65 is for example formed by potentiometer.The load weight sensor 66 that is used for the load weight on the inspection vehicle fork 22 is assemblied in of lift cylinders 25.Load weight sensor 66 links to each other with vehicle control apparatus 52, and detects the fluid pressure in the lift cylinders 25.Load weight relevant detection signal (load signal) on 66 outputs of load weight sensor and the car fork 22.Load weight sensor 66 is for example formed by pressure sensor.

The descending operation bar sensor 67 that is used to detect the amount of movement of descending operation bar 29 is assemblied in descending operation bar 29.The tilt operation bar sensor 68 that is used to detect the amount of movement of tilt operation bar 30 is assemblied in tilt operation bar 30.Descending operation bar sensor 67 links to each other with vehicle control apparatus 52 with tilt operation bar sensor 68, and the amount of movement relevant detection signal of output and descending operation bar 29 and tilt operation bar 30 (descending operation signal and tilt operation signal).The change-over swith 69 that is used to detect the position (progressive position [F], Neutral Position [N], going-back position [R]) of forward/back control lever 31 is assemblied on the forward/back control lever 31.Change-over swith 69 links to each other with vehicle control apparatus 52, and the position relevant detection signal (forward/backward signal) of output and forward/back control lever 31.In the present embodiment, when forward/back control lever 31 is positioned at progressive position [F] or going-back position [R], change-over swith 69 outputs and the cooresponding signal in described position.When forward/back control lever 31 was positioned at Neutral Position [N], change-over swith 69 is output detection signal not.In other words, the CPU54 of vehicle control apparatus 52 reception comes from the detection signal of change-over swith 69 to determine that forward/back control lever 31 is in progressive position [F] or going-back position [R].When not receiving detection signal, CPU54 determines that forward/back control lever 31 is in Neutral Position [N].

Accelerator pedal position sensor 70 is positioned on the acceleration pedal 32 to detect the depression amount of acceleration pedal 32.Accelerator pedal position sensor 70 links to each other with device for controlling engine 53, and output and depression amount relevant detection signal (pedal depression amount signal).When being operated, the acceleration (ON operation) of acceleration pedal 32 instruction fork trucks 10.When unclamping, acceleration pedal 32 does not instruct the acceleration (OFF operation) of fork truck 10.

Have slow break switch 71 on the slow-action pedal 33 to detect the state of stepping on of slow-action pedal 33.Slow break switch 71 links to each other with vehicle control apparatus 52, and exports and step on state relevant detection signal (slow-action signal).Particularly, when power-transfer clutch (forward clutch 42 or back clutch 43) engages, slow break switch 71 output detection signals.Power-transfer clutch (forward clutch 42 or back clutch 43) or be in transferring power engagement state, disconnect the released state of transmission of power, perhaps be in the partial engagement state that switches between engagement state and the released state.Therefore, in the present embodiment, slow break switch 71 is mounted to output detection signal when power-transfer clutch is in engagement state.When power-transfer clutch was in released state (notconnect state) and partial engagement state, slow break switch 71 is output detection signal not.When being operated, slow-action pedal 33 disengage the clutch (ON operation).When being released, slow-action pedal 33 makes clutch engagement (OFF operation).When the operation of slow-action pedal 33 is when the ON operation switches to the OFF operation, fork truck 10 switches to the propulsive effort coupled condition from the propulsive effort off-state.

Have brake switch 72 on the brake pedal 34 to detect the state of stepping on of brake pedal 34.This brake switch 72 is connected on the vehicle control apparatus 52 and the corresponding described state output detection signal (speed-slackening signal) of stepping on.More specifically, when brake pedal 34 is operated, these brake switch 72 output detection signals.When chaufeur is only stepped on brake pedal 34, during brake switch 72 or when chaufeur is stepped on brake pedal 34 and slow-action pedal 33 simultaneously, brake switch 72 output detection signals.When being operated, brake pedal 34 makes drum-type actuator 51 to brake wheel 14 brake activation power (ON operation).When separated, brake pedal 34 stops to make drum-type actuator 51 to drive wheel 14 brake activation power (OFF operation).

In the fork truck 10 of present embodiment, when driving engine 16 is started and forward/back control lever 31 when being in Neutral Position [N], forward relay coil 60b and reverse relay coil 61b are energized with advance normally closed contactor 60a and retreat normally closed contactor 61a of unlatching.Thereby, this electromagnetic valve 44 and retreat electromagnetic valve 45 and do not switch on of advancing.As a result, this forward clutch 42 and back clutch 43 are separated.

After driving engine 16 is by starting, when chaufeur marches forward P PARK Position P [F] when switching with forward/back control lever 31 from Neutral Position [N], vehicle control apparatus 52 receives detection signal from change-over swith 69 (indicate described bar 31 to march forward signal that P PARK Position P [F] switches), and with described forward relay coil 61b deenergization, thereby march forward electromagnetic valve 44 energisings.As a result, forward clutch 42 engages.After driving engine 16 startings, when chaufeur with forward/back control lever 31 when Neutral Position [N] switches to going-back position [R], vehicle control apparatus 52 receives detection signal (indicator stem 31 has been switched to the signal of going-back position [R]) from change-over swith 69, and with reverse relay coil 61b deenergization, electromagnetic valve 45 energisings of drawing back thus.As a result, back clutch 43 engages.When chaufeur bend the throttle 32, device for controlling engine 53 receives from the detection signal (signal of the depression amount of corresponding acceleration pedal 32) of accelerator pedal position sensor 70 and controls throttle valve drive device 35.Thereby the rotating speed of driving engine 16 is correspondingly adjusted, and fork truck 10 is along travelling with forward/back control lever 31 corresponding directions (working direction or direction of retreat).

When pilot control descending operation bar 29, vehicle control apparatus 52 receives from the detection signal (with the cooresponding signal of the operational ton of descending operation bar 29) of descending operation bar sensor 67 and controls the lifting/lowering solenoid electric valve 39 that car is pitched.When chaufeur was handled tilt operation bar 30 in loading process, vehicle control apparatus 52 received from the detection signal (with the cooresponding signal of the operational ton of tilt operation bar 30) of tilt operation bar sensor 68 and controls car fork inclination solenoid electric valve 38.Next, when chaufeur is stepped on slow-action pedal 33 in loading process, thereby cause power-transfer clutch (forward clutch 42 and back clutch 43) partial engagement or separate, and bend the throttle 32.These operations (action) cause driving engine 16 to rotate to drive Hydraulic Pump 36.When descending operation bar 29 was operated, hydraulic oil was fed into hydraulic lifting cylinder 25 by car fork lifting/lowering solenoid electric valve 39.When tilt operation bar 30 was operated, hydraulic oil was provided to hydraulic tilting cylinder 24 by car fork inclination solenoid electric valve 38.As a result, hydraulic lifting cylinder 25 stretches out according to the direction of operating of descending operation bar 29 or withdraws, and car fork 22 also is raised thus or descends.Similarly, hydraulic tilting cylinder 24 stretches out according to the direction of operating of tilt operation bar 30 or withdraws, and strut assemblies 19 (car fork 22) also tilts therefrom forward or backward.In the loading operation process of fork truck 10, slow-action pedal 33 is operated, and described power-transfer clutch (forward clutch 42 and back clutch 43) is partly engaged or separates (separation).When fork truck 10 was driven behind loading operation, slow-action pedal 33 was separated, thereby power-transfer clutch (forward clutch 42 and back clutch 43) is engaged.Then, acceleration pedal 32 is operated with the acceleration that gives an order.

In the fork truck 10 of the present embodiment of as above constructing, vehicle control apparatus 52 and device for controlling engine 53 are carried out vehicular drives control and vehicle launch control, improve the driving stability of fork truck 10 in driving and starting process thus.Vehicular drive control is meant that the max speed and acceleration/deceleration are according to the confined control of load condition in the driving process.Vehicle launch control is meant that the starting of vehicle is according to load condition and the confined control of engine speed.In the present embodiment, vehicle launch control prevents the vehicle fly start.Load condition is represented the state of the load on the car fork 22.In the present embodiment, determine described load condition based on height, weight and angle of inclination.In fork truck 10,, may become harsh by load condition so if the height of car fork 22 increases, the weight of load increases and the angle of inclination exceeds the angular range that recedes (for example, turning forward).In other words, in driving and starting process, it is unstable that vehicle may become.When driving engine 16 is accelerated to a higher engine speed, when propulsive effort is access in, cause fly start.Load condition is harsh more, and vehicle is more possible owing to fly start becomes unstable.

Hereinafter, vehicular drive control (control of the max speed and acceleration/deceleration) and vehicle launch control (control of fly start) will be described.Vehicle control apparatus 52 and device for controlling engine 53 are carried out these control according to control program.

The mapping (enum) data that is stored in the memory device 55 of vehicle control apparatus 52 is illustrated with reference to Fig. 4 to Fig. 6.

The mapping (enum) data of Fig. 4 relates to and is used for determining whether load condition needs to limit the driving (hereinafter, being called as necessary determination data) of fork truck 10.In the present embodiment, this necessity determination data has defined restricted areas and unrestricted zone, in restricted areas,, or limit maximum speed and acceleration/deceleration, in unrestricted zone, do not impose any restriction based on car fork height and load weight based on two parameters.Particularly, highly be equal to or greater than car fork height H and load weight with car fork and be equal to or greater than the corresponding zone of load weight W and be set to restricted areas, be set to unrestricted zone less than car fork height H or load weight less than the cooresponding zone of load weight W with car fork height.In necessary determination data shown in Figure 4, the zone that the car fork is highly high and load weight is heavy, or the zone of load condition harshness is set to restricted areas.In Fig. 4, this restricted areas is by the diagonal line hatches region representation.

The mapping (enum) data of Fig. 5 is used under the confined situation of the max speed, just, and when determining that based on the necessary determination data of Fig. 4 load condition calculates the max speed value when being in restricted areas.The mapping (enum) data of Fig. 5 is called as speed of a motor vehicle computational data hereinafter.In the present embodiment, speed of a motor vehicle computational data is based on two parameters, or determines the max speed value [km/h] based on load weight and leaning angle.Particularly, the load region that is equal to or greater than load weight W is divided into a plurality of zones (being five zones of A, B, C, D, E shown in Fig. 5 in the present embodiment), and whether is in the scope of receding based on described leaning angle in each zone in described five zones and determines the max speed value.The situation that described leaning angle is in the scope of receding is meant that strut assemblies 19 (car fork 22) is with respect to car body 11 sweptback situations (state recedes).Other situation that is different from the scope of receding is meant that strut assemblies 19 is the situation of vertical (car fork 22 is levels) and the situation (state turns forward) that strut assemblies 19 turns forward with respect to car body 11.

According to the speed of a motor vehicle computational data of Fig. 5, the max speed under the situation of leaning angle in the scope of receding is represented by solid line.The leaning angle not the max speed under the situation in the scope of receding is illustrated by the broken lines.For example, in regional A, the max speed under the situation of leaning angle in the scope of receding is set to 15 (km/h), and leaning angle not the max speed under the situation in the scope of receding be set to 12 (km/h).In other words, in the time of in leaning angle is not receding scope, the center of gravity of load is positioned at the front portion of vehicle.On the other hand, in the time of in leaning angle is receding scope, the center of gravity of this load is positioned at the rear portion of vehicle.Therefore, in the time of in leaning angle is not receding scope, its load condition is harsher than the situation of leaning angle in the scope of receding.Thereby even the weight of load is identical, the max speed value also can change according to leaning angle.In the time of in leaning angle is not receding scope, the max speed is set to the max speed that is lower than under the situation of leaning angle in the scope of receding.

The mapping (enum) data of Fig. 6 is used under the confined situation of acceleration/deceleration, just, when determining that based on the necessary determination data of Fig. 4 load condition is in restricted areas, calculates the acceleration/deceleration value.The mapping (enum) data of Fig. 6 is called as the acceleration/deceleration computational data hereinafter.In the present embodiment, this acceleration/deceleration computational data is based on two parameters, or load weight and leaning angle definition acceleration/deceleration value [km/h/s].Particularly, whether the load region that is equal to or greater than load weight W is divided into a plurality of zones (being five zones of A, B, C, D, E shown in Fig. 5 in the present embodiment), and be in each zone in five zones based on leaning angle and determine the acceleration/deceleration value in the scope of receding.[km/h/s is that the acceleration/deceleration value with per second is converted into acceleration/deceleration value hourly and the value that obtains.In the acceleration/deceleration data of Fig. 6, the load region that is equal to or greater than weight W is divided into the gravimetric value identical with the speed of a motor vehicle computational data of Fig. 5.

According to the acceleration/deceleration computational data of Fig. 6, the acceleration/deceleration value that leaning angle is under the interior situation of the scope of receding is represented by solid line.The acceleration/deceleration value that leaning angle is under the situation outside the scope of receding is illustrated by the broken lines.For example in regional A, the acceleration/deceleration value that leaning angle is under the situation in the scope of receding is set to 4km/h/s, and the acceleration/deceleration value that leaning angle is under the situation outside the scope of receding is set to 3km/h/s.In other words, even load weight is identical, this acceleration/deceleration value also can change according to leaning angle.In the time of outside leaning angle is positioned at the scope of receding, the acceleration/deceleration value is set to less than leaning angle and is in acceleration/deceleration value under the situation in the scope of receding.Hereinafter, acceleration/deceleration data shown in Fig. 6, the acceleration/deceleration value of the acceleration/deceleration value of 1km/h/s, the acceleration/deceleration value of 2km/h/s, 3km/h/s and the acceleration/deceleration value of 4km/h/s are called as acceleration/deceleration grade 1, acceleration/deceleration grade 2, acceleration/deceleration grade 3 and acceleration/deceleration class 4 where necessary respectively.

Arrive the content of Fig. 9 description below with reference to Fig. 7 by the control of the CPU54 execution of vehicle control apparatus 52.

Fig. 7 has shown the restriction deterministic process that is used to limit the max speed and acceleration/deceleration.Fig. 8 has shown the starting control process of the starting that is used to control fork truck 10.Fig. 9 is the engine retard process that is used to reduce engine speed.Described engine retard process is performed during the starting control process.Make engine retard mean the rotating speed that reduces driving engine 16.In the present embodiment, CPU 54 usefulness of the starting control process shown in the restriction deterministic process shown in the execution graph 7 and Fig. 8 connect determining section, load condition determining section, engine speed determining section and disconnect control part.In the present embodiment, the CPU 54 of engine retard process shown in the execution graph 9 and under the instruction of the CPU 54 that carries out the engine retard process CPU 57 of the device for controlling engine 53 of control driving engine 16 as the motor speed control part.

At first, will the restriction deterministic process of Fig. 7 be described.CPU 54 carries out expectant control cycle of described restriction deterministic process.

In this restriction deterministic process, the information that CPU 54 obtains with car is pitched highly, load weight is relevant with the angle of inclination is used for determining load condition (step S10).In step S10, CPU 54 obtains car fork height, leaning angle and load weight from the detection signal from height sensor 64, gradient sensor 65 and load weight sensor 66.Subsequently, CPU 54 is with reference to the necessary determination data (step S11) shown in Fig. 4, and determines based on information of obtaining in step S10 relevant with load weight with car fork height and the data of Fig. 4 whether this load condition needs the speed of a motor vehicle (the max speed and acceleration/deceleration) is limited (step S12).In step S12, CPU 54 judges whether load condition is in the restricted areas of corresponding high car fork height and heavy lift weight.

If the judged result of step S12 is sure (needing restriction), then CPU 54 is with reference to the speed of a motor vehicle computational data (step S13) among Fig. 5, and chooses the max speed value (step S14) based on this comparable data with the information relevant with load weight and angle of inclination that obtains in step S10.In step S14, for example,, then be positioned at when receding scope when leaning angle if load weight is positioned at area B, CPU 54 chooses 13km/h as the max speed value, in the time of outside leaning angle is positioned at the scope of receding, then chooses 10km/h.Choose in step S14 after the max speed value, CPU 54 is stored in selected the max speed value in the memory device 55.

Subsequently, CPU 54 is with reference to the acceleration/deceleration data (step S15) among Fig. 5, and chooses acceleration/deceleration value (step S16) based on the data of institute's reference with the information relevant with load weight and angle of inclination that obtains at step S10.In step S16, for example, if load weight is positioned at area B, in the time of then in leaning angle is in the scope of receding, CPU 54 chooses 3km/h/s as the acceleration/deceleration value, in the time of outside leaning angle is in the scope of receding, then chooses 2km/h/s.Choose in step S16 after the acceleration/deceleration value, CPU 54 is stored in the acceleration/deceleration value of selecting in the memory device 55.

Subsequently, CPU 54 sends restricting signal to specify in the max speed value of choosing among the step S14 and the acceleration/deceleration value of choosing in step S16 to device for controlling engine.After this, CPU 54 stops described restriction deterministic process.If the judged result of step S12 is negative (not needing restriction), then CPU 54 advances to step S17, and sends restricting signal to device for controlling engine, to instruct it not limit the max speed and acceleration/deceleration.If the judged result of step S12 is for negating, then CPU 54 fact that will not need to limit the max speed and acceleration/deceleration is stored in the memory device 55.After this, CPU 54 stops this restriction deterministic process.When the judged result of step S12 for negate the time, then load condition is in unrestricted zone (low car fork height or underload weight).

Below description is presented at the starting control process among Fig. 8 and is presented at the engine retard process that the subprogram as described starting control process among Fig. 9 is carried out.CPU54 carries out the limit procedure control cycle in each expectant control in the cycle.

In the starting control process, CPU54 judges whether to connect propulsive effort (step S20).In other words, in step S20, CPU54 judges whether the propulsive effort off-state has switched to the propulsive effort coupled condition.In current embodiment, in step S20, the input of the detection signal of CPU54 monitoring slow break switch 71, and based on whether having the detection signal input to carry out judgement.When slow break switch 71 received detection signal, in step S20, CPU54 did not detect the propulsive effort off-state and has been transformed into the propulsive effort coupled condition when receive detection signal from slow break switch 71 in a period of time after.In this case, the judged result of step S20 is sure.When not receiving detection signal, the judged result of step S20 negates.

If the judged result of step S20 is sure, CPU54 determines whether the max speed and acceleration degree need to be limited (step S21) so.CPU54 is based on the judgement of restriction deterministic process at the judged result execution in step S21 at step S21 place.When memory device 55 remained with the max speed value and acceleration/deceleration value, the judged result of CPU54 determining step S21 was sure.When if memory device 55 does not keep the max speed value and acceleration/deceleration value, the judged result of CPU54 determining step S21 negates.

If the judged result of step S21 is sure, CPU54 obtains the information relevant with engine speed to determine the engine speed (acceleration mode of driving engine 16) (step S22) when the propulsive effort off-state is transformed into the propulsive effort coupled condition so.In step S22, CPU54 obtains engine speed from engine speed sensor 62.CPU54 receives and obtains the engine speed that the CPU57 by device for controlling engine 53 obtains by device for controlling engine 53.Then, the engine speed (being represented by M in Fig. 8) that CPU54 will obtain in step S22 compares with preestablished limit engine speed (being represented by Ma in Fig. 8), and whether definite engine speed M is more than or equal to limit engine speed Ma (step 23).Limit engine speed Ma is set at greater than speed without load (engine speed during idle running).In the present embodiment, limit engine speed is set at 1700rpm.In step S23, CPU54 determines whether the propulsive effort off-state switches to the propulsive effort coupled condition under a high engine speed, in other words, determines when driving engine 16 is accelerated.Limit engine speed Ma be considered (limit amount in the driving process) behind the load condition by experiment (simulation) what kind of engine speed when finding in starting stability is reduced and the value obtained.Therefore, limit engine speed Ma is according to the type of fork truck 10 and difference.

As (the Ma≤M) of the judged result among the step S23 when being sure, CPU54 judges whether the acceleration/deceleration value of determining is 1km/h/s or 2km/h/s in the step S16 of restriction deterministic process, in other words, judge whether the acceleration/deceleration grade is [1] or [2] (step S24).Four acceleration/deceleration grades [1] in present embodiment arrive in [4], and acceleration/deceleration grade [1] and [2] are and the corresponding grade of the situation of load condition harshness.

If the judged result of step S24 is sure, CPU54 disconnects propulsive effort (step S25) by force so.In step S25, CPU54 controls and advances electromagnetic valve 44 or retreat electromagnetic valve 45, forces to disconnect propulsive effort thus.Particularly, when the detection signal of the change-over swith 69 of the position that is used to detect forward/back control lever 31 indicates progressive position [F] or going-back position [R], CPU54 excitation forward relay coil 60b and reverse relay coil 61b.In other words, when advance relay coil 60b and reverse relay coil 61b were energized, normally closed contactor 60a and retreat normally closed contactor 61a and open advanced.Therefore, the electromagnetic valve 44 and retreat not energising of electromagnetic valve 45 of advancing, and the degree maximum of opening.Therefore, forward clutch 42 and back clutch 43 are supplied with hydraulic oil by the operation of Hydraulic Pump 46, and therefore separate.This makes propulsive effort disconnect.In step S25, CPU54 carries out and disconnects control to force to disconnect propulsive effort.

After step S25, the engine retard process (step S26) that shows in the CPU54 execution graph 9.The engine retard process is to be used for engine speed is reduced to the process that is equal to or less than predetermined engine speed (in the present embodiment, being 1000rpm).After the engine retard process, CPU54 carries out the step S27 in the starting control process.In step S27, the off-state of CPU54 cancellation propulsive effort inserts propulsive effort thus once more.In step S27, CPU54 controls and advances electromagnetic valve 44 or retreat electromagnetic valve 45, inserts propulsive effort thus once more.Particularly, when the detection signal indication progressive position [F] of the change-over swith 69 of the position that is used to detect forward/back control lever 31 or going-back position [R], the CPU54 de excitation is encouraged relevant among forward relay coil 60b and the reverse relay coil 61b.In other words, when advance relay coil 60b and reverse relay coil 61b were encouraged by de excitation, normally closed contactor 60a and retreat normally closed contactor 61a and close advanced.Therefore, advance electromagnetic valve 44 and retreat the electromagnetic valve energising and close fully.Therefore, the hydraulic oil that is provided by the operation of Hydraulic Pump 46 is be provided for forward clutch 42 and back clutch 43, and therefore engages.This makes propulsive effort insert.Therefore, propulsive effort (power of driving engine 16) is delivered to drive wheel 14 via change-speed box 18, thereby but makes fork truck 10 be in driving condition.In the present embodiment, the engine retard process is performed in the starting control process, thereby makes vehicle control apparatus 52 off-state of cancellation propulsive effort automatically.

After step S27, CPU54 finishes the starting control process.When the judged result of step S24 for negate the time, the acceleration/deceleration grade is [3] or [4].In this case, CPU54 carries out the engine retard process in step S28.Engine retard process among the step S28 identical with the engine retard process of in step S26, carrying out (Fig. 9).After the engine retard process of step S28, CPU54 finishes the starting control process.And, when the judged result of step S20, S21 for negate the time, CPU54 finishes the starting control process.When the judged result of step S20 for negate the time, disengaging of clutch or vehicle begin to advance.And, when the judged result of step S21 for negate the time, load condition does not limit the driving of vehicle.

In the present embodiment, even the max speed and acceleration/deceleration are restricted in the step S24 of starting control process, also can further divide state according to the acceleration/deceleration grade, and the limiting content in when starting is distinguished (, according to the degree of susceptibility of stability when the starting) between the limiting content of harshness and the limiting content that loosens.In other words, even the engine retard process shown in Fig. 9 is performed, the rotating speed of driving engine 16 can not drop to the desired speed that is equal to or less than predetermined driving engine at once yet, but needs some times to reduce.Therefore, be confirmed as in a kind of acceleration/deceleration grade under the load condition of harshness of [1] or [2] (the car fork is highly high or load heavy), the control that is used to reduce engine speed can not drop to engine speed enough grades, and consequently, it is unstable that the starting of vehicle becomes.Therefore, according to present embodiment, under the load condition of aforesaid harshness, except reducing engine speed, propulsive effort also is forced to disconnect, so the driving of vehicle (starting) is suspended until driving engine 16 decelerations (driving of vehicle (starting) is restricted) by interim.When engine speed dropped to desired speed, propulsive effort was access in, thereby made vehicle to be driven.On the other hand, be confirmed as in the acceleration/deceleration grade under the load condition of [3] or [4], that is, do not needing by reducing engine speed to disconnect under the load condition that propulsive effort just might stably drive, only engine speed is controlled.

Engine retard process shown in Fig. 9 is described below.

In the engine retard process, CPU54 is to the CPU57 of device for controlling engine 53 output request signal, and this request signal is used for carrying out racing of the engine request (reducing the request of driving engine 16 rotating speeds) at step S30.When receiving request signal, CPU57 controls throttle valve drive device 35, regulates the rotating speed of driving engine 16 thus.Do not consider the testing result (depression amount of acceleration pedal 32) of accelerator pedal position sensor 70, CPU57 control driving engine 16 is to reduce engine speed.

Behind step S30, CPU54 obtains the information relevant with engine speed (step S31).In step S31, CPU54 obtains engine speed in the mode identical with the step S22 of the starting control process shown in Fig. 8.Then, the engine speed (representing with M in Fig. 9) that CPU54 will obtain in step S31 is compared with predetermined cancellation limiting engine rotating speed (representing with Mb in Fig. 9), and judges whether engine speed M is less than or equal to cancellation limiting engine rotating speed Mb (step S32).Cancellation limiting engine rotating speed Mb is set at less than limit engine speed Ma.In the present embodiment, cancellation limiting engine rotating speed Mb is set at 1000rpm.Cancellation limiting engine rotating speed Mb is considering behind the load condition (limiting content in the driving process) that (simulation) by experiment keeps the degree of engine speed reduction of vehicle stabilization when finding out in starting and the value obtained.Therefore, cancellation limiting engine rotating speed Mb looks the type of fork truck 10 and difference.If the judged result among the step S32 be negate (Mb＜M), CPU54 enters step S31 and begins to repeat this process from step S31 so.On the other hand, when the judged result of step S32 be that sure (during Mb 〉=M), CPU54 finishes the engine retard process and turns back to the starting control process.

Then, will the content of being controlled by device for controlling engine 53 (particularly, the max speed and acceleration/deceleration control content) be described with reference to Figure 10.

Figure 10 shown be used for calculation engine speed adjustment amount mapping (enum) data (hereinafter, be called engine speed and regulate data), this mapping (enum) data is stored in the memory device 58 of device for controlling engine 53, value based on the max speed value of in step S14, the S16 of restriction deterministic process shown in Figure 7, choosing and acceleration/accel/deceleration, the CPU57 of device for controlling engine 53 regulates data computation from engine speed and goes out the engine speed regulated quantity, and the control engine speed.When the driving of vehicle is restricted, thereby CPU57 control driving engine 16 makes the speed of a motor vehicle be equal to or less than the max speed value, and does not consider the testing result (depression amount of acceleration pedal 32) of accelerator pedal position sensor 70.In other words, when the max speed and acceleration/deceleration were restricted, even the complete bend the throttle 32 of chaufeur, fork truck 10 can not be driven with the speed of a motor vehicle that surpasses the max speed value yet.And acceleration degree and degree of deceleration are according to the acceleration/deceleration grade and different.

It is the figure that concern between difference (hereinafter, be called the speed of a motor vehicle poor) between a reflection the max speed value and the actual vehicle speed and the engine speed regulated quantity that the engine speed of current embodiment is regulated data.Above-mentioned relation is determined to [4] according to four acceleration/deceleration grades [1].Speed of a motor vehicle difference is the max speed value chosen and by the difference between the car speed sensor 63 detected speed of a motor vehicle in the step S14 of restriction deterministic process.Regulate in the data at engine speed, the relation between speed of a motor vehicle difference and the engine speed is defined as, and along with speed of a motor vehicle difference increases, the engine speed regulated quantity increases.Relation between speed of a motor vehicle difference and the engine speed regulated quantity is defined like this, promptly along with the acceleration/deceleration grade near grade [1] (along with load condition becomes harsh), the engine speed regulated quantity reduces with respect to speed of a motor vehicle difference.In other words and since along with the acceleration/deceleration grade near grade [1], the engine speed regulated quantity descends, so fork truck 10 is by gentle acceleration and deceleration gradually.

When restriction the max speed and acceleration/deceleration, the CPU57 of device for controlling engine 53 regulates the rotating speed of driving engine 16 in the following manner.

In cycle, CPU57 obtains current vehicle speed from the detection signal of car speed sensor 63 in each predetermined control, and deducts the speed of a motor vehicle that is obtained from the max speed value, and it is poor to calculate the speed of a motor vehicle thus.Subsequently, CPU57 obtains the acceleration/deceleration value (value of acceleration/deceleration grade) that is stored in the memory device 58.Based on speed of a motor vehicle difference and acceleration/deceleration grade, the engine speed that CPU57 shows from Figure 10 is regulated data computation engine speed regulated quantity.After having calculated the engine speed regulated quantity, CPU57 regulates throttle opening thus based on described regulated quantity control throttle valve drive device 35.Therefore, the rotating speed of driving engine 16 is regulated.In other words, CPU57 carries out controlled reset, thereby makes actual vehicle speed can not surpass the max speed value.

Present embodiment has following advantage.

(1) when the operation by chaufeur (in the present embodiment, when the operation for slow-action pedal 33) the propulsive effort off-state is switched to the propulsive effort coupled condition, if load condition needs to limit on the vehicle and engine speed M is equal to or greater than limit engine speed Ma, propulsive effort is forced to interrupt to the transmission on the drive wheel 14 so.Because the propulsive effort off-state is switched to the propulsive effort coupled condition, so fork truck 10 is in drivable state, i.e. starting state.If in the acceleration (when acceleration pedal 32 is operated) that gives an order of propulsive effort off-state, the driving engine 16 of fork truck 10 is accelerated to rotate so, and engine speed M increases.Therefore, need vehicular drive to be restricted under the state of (for example, the car fork is highly high or load weight is big) and driving engine 16 quickening rotations at load condition, the starting of fork truck 10 may cause that driving is unstable.In other words, fork truck 10 may may cause under the vehicular drive unsure state by fly start at load condition.Therefore, under the propulsive effort coupled condition,, can avoid fork truck 10 to start may causing under the vehicular drive unsure state by forcing to disconnect propulsive effort according to load condition and engine speed.In other words, the stability of fork truck 10 when starting is guaranteed, and this is not to obtain by control the max speed and acceleration/deceleration in the driving process of fork truck 10.

(2) particularly, under the situation of the fork truck 10 of present embodiment, identical drive source (driving engine 16) is used for driving and loading.In this case, disconnect propulsive effort by stepping on slow-action pedal 33.Under this state, acceleration pedal 32 is operated to actuate bogey 12.Therefore, when bogey 12 was actuated, stepping on of acceleration pedal 32 made driving engine 16 rotate quickening, and engine speed increases.Under this working environment, when for example chaufeur lifted slow-action pedal 33, the propulsive effort off-state switched to the propulsive effort coupled condition.This may cause fork truck 10 fly starts.In other words, fork truck 10 starts may causing under the unsettled condition of vehicular drive.Therefore, under described working environment, the driving stability of fork truck 10 is guaranteed.

(3) when propulsive effort is forced to disconnect, carry out a control engine speed M is reduced to the value that is equal to or less than cancellation limiting engine rotating speed Mb.Because engine speed M is lowered to the value that is equal to or less than cancellation limiting engine rotating speed Mb, therefore, the propulsive effort off-state is cancelled.When the propulsive effort off-state was cancelled, propulsive effort recovered to the transmission of drive wheel 14, thereby makes fork truck 10 to drive.Therefore, owing to fork truck 10 is started with the engine speed M that reduces, so fork truck 10 is started in a kind of pulsation-free mode.In other words, prevent fork truck 10 fly starts, and starting stability is guaranteed.

(4) determine based on the serviceability of slow-action pedal 33 whether described state is switched to the propulsive effort coupled condition.Determine based on judged result whether propulsive effort will be disconnected (the step S23 of the starting control process that shows among Fig. 8).When chaufeur driving fork truck 10 is advanced (engaging clutch) or made fork truck 10 not advance (cut-off clutch), use slow-action pedal 33 to express the intentions of chaufeur.Therefore, by carrying out aforementioned deterministic process, when slow-action pedal 33 was operated, propulsive effort was forced the notified chaufeur of open circuited reason in the driving process.

Control content when (5) starting changes according to load condition.Particularly, when the acceleration/deceleration grade is [1] or [2], carry out the control that is used to disconnect propulsive effort and reduces engine speed.When the acceleration/deceleration grade is [3] or [4], carry out the control that is used to reduce engine speed.Therefore, under the state that can not only handle by control engine speed (driving engine 16), propulsive effort disconnects and connecting, thereby has avoided fly start reliably.On the other hand, under the state that can only handle, can reliably avoid fly start by the control engine speed, and not need to disconnect propulsive effort by control engine speed (driving engine 16).In other words, when propulsive effort disconnected, electromagnetic valve 44 and retreat electromagnetic valve 45 and be controlled to disconnect propulsive effort reliably and the structure of fork truck 10 is complicated advanced.Vehicle for example fork truck 10 is started repeatedly and is stopped.Therefore, when control that execution is used to start, the excitation number of times that is used to drive the relay circuit (forward relay circuit 60 and reverse relay circuit 61) of electromagnetic valve 44,45 may increase.Therefore, because propulsive effort is optionally disconnected according to load condition and is connected, can carry out the excitation number of times that starts control and do not need the additive incrementation relay circuit.

11 second embodiment of the present invention is described below with reference to the accompanying drawings.In the following embodiments, will omit and simplify the explanation of the same parts in the embodiment of having described.

In the present embodiment, when propulsive effort was forced to disconnect, off-state was eliminated by the operation of chaufeur.Particularly, the execution of the ON operation of the acceleration pedal 32 after the OFF operation that executes acceleration pedal 32 is set to the cancellation condition with the cancellation off-state.Figure 11 shows in the present embodiment, the starting control process of being carried out by the CPU54 of vehicle control apparatus 52.

The starting control process of present embodiment will be described with reference to Figure 11.In Figure 11, to these steps identical with corresponding steps in the starting control process (Fig. 8) of first embodiment titled with identical Reference numeral.Hereinafter, will omit or simplify, and mainly describe different processes for the unnecessary explanation of identical process.

In the starting control process that shows in Figure 11, when the judged result of step S23 when being sure, in step S24, the CPU54 of vehicle control apparatus 52 determines whether the acceleration/deceleration grade is [1] or [2].If the judged result among the step S24 is sure, in step S25, CPU54 forces to disconnect propulsive effort so.In step S25, with identical in first embodiment, CPU54 controls and advances electromagnetic valve 44 and retreat electromagnetic valve 45, disconnects propulsive effort thus.After propulsive effort was disconnected in step S25, in step S40 and S41, CPU54 determined whether above-described cancellation condition satisfies.

At first, in step S40, CPU54 receives detection signal from the accelerator pedal position sensor 70 that is positioned on the acceleration pedal 32, and obtains the depression amount (accelerator pedal position) of acceleration pedal 32.When the detection signal of accelerator pedal position sensor 70 was zero, CPU54 detected acceleration pedal 32 and is not operated (OFF operation).When the detection signal of accelerator pedal position sensor 70 indication during greater than zero value, accelerator pedal position sensor 70 detects acceleration pedal 32 and is operated (ON operation).Whether based on the information of obtaining in step S40, in step S41, CPU54 determines whether the cancellation condition satisfies, that is, be performed in the OFF operation ON operation of acceleration pedal 32 afterwards.

If the judged result among the step S41 is sure, in step S27, with identical in first embodiment, CPU54 controls and advances electromagnetic valve 44 and retreat electromagnetic valve 45, cancels the propulsive effort off-state thus so.Therefore, propulsive effort (power of driving engine 16) is delivered to drive wheel 14 via change-speed box 18, thereby but makes vehicle be in driving condition.On the other hand, if the judged result of step S41 negates that CPU54 returns the process of step S40 and repeating step S40, S41 so.In other words, CPU54 keeps the propulsive effort off-state up to satisfying the cancellation condition.

Therefore, except (1), (2) and (4) bar advantage of first embodiment, second embodiment also provides following advantage.

(6) when propulsive effort is forced to disconnect, if chaufeur is carried out the ON operation of acceleration pedal 32 in OFF operation back, the propulsive effort off-state is cancelled so.When chaufeur was carried out the ON operation of acceleration pedal 32, the engine speed M of fork truck 10 increased to meet or exceed limit engine speed Ma.When chaufeur was carried out the OFF operation of acceleration pedal 32, engine speed M reduced.By making chaufeur carry out this sequence of operations, guaranteed in order to the time of reducing engine speed M, thereby make fork truck 10 under the situation that engine speed M descends, allow to be driven.In other words, prevent fork truck 10 by fly start, and the stability when guaranteeing to start.

Below with reference to Figure 12 and Figure 13 the 3rd embodiment of the present invention is described.This embodiment can be applied to first and second embodiments.

In this embodiment, in the step S20 of the starting control process shown in Fig. 8, determine by detecting the forward clutch 42 and the pressure receiving cavity 42a of back clutch 43, the clutch pressure of 43a, carrying out whether the propulsive effort off-state has been transformed into the process of propulsive effort coupled condition.

The structure of the fork truck 10 of present embodiment is described below with reference to Figure 12.Figure 12 mainly shown with first embodiment in the different place of fork truck 10 (being presented among Fig. 3) described.The parts (structure) that are not presented among Figure 12 are identical with those parts (structure) of fork truck 10 in being presented at Fig. 3.

As shown in Figure 12, forward clutch 42 and back clutch 43 have the clutch pressure (hydraulic pressure) of clutch pressure sensor 80,81 with detected pressures reception cavity 42a, 43a. Clutch pressure sensor 80,81 links to each other with vehicle control apparatus 52, and the hydraulic pressure among detected pressures reception cavity 42a, the 43a.80,81 outputs and the cooresponding detection signal of hydraulic coupling (clutch pressure signal) of clutch pressure sensor. Clutch pressure sensor 80,81 is for example formed by pressure sensor.The slow-action pedal 33 of present embodiment has slow-action pedal position sensor 82, to detect the depression amount (pedal stroke) of slow-action pedal 33.Slow-action pedal position sensor 82 links to each other with vehicle control apparatus 52, and output and depression amount relevant detection signal (pedal depression amount signal).Identical in the operating mode of slow-action pedal 33 and first embodiment.In other words, when being operated, slow-action pedal 33 is operated with cut-off clutch.When unclamping, slow-action pedal 33 is operated with engaging clutch.

Memory device 55 storages of vehicle control apparatus 52 are presented at the mapping (enum) data (hereinafter, being called the connection determination data) among Figure 13.Connect determination data and be the figure that concerns between a depression amount that has reflected slow-action pedal 33 and the clutch pressure.When the clutch pressure among pressure receiving cavity 42a, the 43a of the forward clutch 42 of present embodiment and back clutch 43 descends, thereby engaging force increases and makes clutch engagement.When clutch pressure increased, engaging force reduced, thereby power-transfer clutch is separated.In other words, when the depression amount of slow-action pedal 33 hour, clutch engagement and clutch pressure reduce.When the depression amount of slow-action pedal 33 is big, disengaging of clutch, and clutch pressure increases.Connect determination data and comprise two determined values, or a joint determined value separates determined value to determine clutch engagement or separation with one.Exist between these two values and lag behind.In other words, connecting determination data and have three zones, is respectively engaging zones, part calmodulin binding domain CaM and separated region, and these three zones are by engaging determined value and separating the determined value division.When the ON of slow-action pedal 33 operation was performed (depression amount increase), the partial engagement zone was included in the engaging zones, and when the OFF of slow-action pedal 33 operation was performed (depression amount reduces), the partial engagement zone was included in the separated region.

Below, with the process of carrying out by CPU54 among the step S20 of the starting control process that in Fig. 8, shows of explanation.

Among the step S20 of the starting control process that shows in Fig. 8, CPU54 receives detection signal from clutch pressure sensor 80,81, and obtains the clutch pressure among pressure receiving cavity 42a, the 43a.Subsequently, based on the information of the depression amount of clutch pressure that is obtained and slow-action pedal 33, CPU54 is by judging that with reference to connecting determination data power-transfer clutch is engaged or separates.In the present embodiment, CPU54 receives the detection signal of slow-action pedal position sensor 82 in each predetermined control in the cycle.The testing result that CPU54 will obtain in current control cycle (depression amount of slow-action pedal 33) is compared with the testing result of obtaining in control cycle last time, and the result judges whether the OFF operation of the ON operation of slow-action pedal 33 is performed based on the comparison.When determining clutch engagement based on the serviceability of clutch pressure and slow-action pedal 33, the result of CPU54 determining step S20 is sure.When determining disengaging of clutch, CPU54 finishes the starting control process.In other words, when the ON of slow-action pedal 33 operation was performed, if clutch pressure is equal to or less than the separation determined value, CPU54 determined that power-transfer clutch is separated so.When the OFF of slow-action pedal 33 operation was performed, if clutch pressure is equal to or less than the joint determined value, CPU54 determined that power-transfer clutch is engaged so.

Therefore, except (1) to (5) bar advantage of first embodiment, the 3rd embodiment also provides following advantage.

(7) determine based on the serviceability of slow-action pedal described state whether the clutch pressure (hydraulic pressure) in responsive clutch (forward clutch 42 and back clutch 43) pressure receiving cavity 42a, the 43a be switched under the situation of propulsive effort coupled condition, testing result depends on the assembly precision that is used for detecting operation status detection part (for example, slow break switch 71 and slow-action pedal position sensor 82).In other words, if even power-transfer clutch does not engage but power-transfer clutch is judged joint in control program, so described determine and driving engine 16 speed-raisings between the life period sluggishness.Therefore, in other words, the control that is used for starting (being presented at the starting control process of Fig. 8 and Figure 11) may not be performed, and the vehicle fly start.And, if even power-transfer clutch be engaged but in control program power-transfer clutch be judged separation, even the control that is used to so start is not performed.In this case, vehicle may fly start.Yet in the present embodiment, the clutch pressure in pressure receiving cavity 42a, the 43a is directly detected with the improvement accuracy of detection and is judged precision, and judges whether described state has switched to the propulsive effort coupled condition.Therefore, judge that precision is improved, and further prevent the vehicle fly start reliably.

14 and 15 the 4th embodiment of the present invention is described below with reference to the accompanying drawings.Present embodiment can be applied to first to the 3rd embodiment.

In the present embodiment, when determining propulsive effort when the propulsive effort off-state switches to the propulsive effort coupled condition (when the judged result of the step S20 of fly start control process when being sure), engine speed M monitored behind the time point of making judgement predetermined amount of time in the past.If in the predetermined amount of time that begins from the time point of making judgement, engine speed M meets or exceeds limit engine speed Ma, and propulsive effort is forced to disconnect so.In the present embodiment, described predetermined amount of time is set at 0.5 second.

When Figure 14 (a) shows that to Figure 14 (d) from acceleration pedal 32 and slow-action pedal 33 one of pin when chaufeur moves on another, the variation of acceleration pedal 32 depression amount, slow-action pedal depression amount, engine speed and the speed of a motor vehicle.Figure 14 (a) is mutually related to Figure 14 (d), and transverse axis is shared time axis.

To shown in Figure 14 (d), even acceleration pedal 32 is operated, the engine speed and the speed of a motor vehicle can not rise along with stepping on action fully synchronously yet, but rise after a delay as 14 (a).Particularly, the depression amount of acceleration pedal 32 causes that at first engine speed rises.Then, the speed of a motor vehicle rises.Therefore, when chaufeur conversion pedal, if power-transfer clutch engages with the acceleration pedal 32 that is being operated, engine speed M may be in the low engine speed region that is lower than limit engine speed Ma when engaging so.In the present embodiment, consider the delay that engine speed M rises, engine speed M is monitored up to the schedule time in past.

Below, will be with reference to the starting control process of Figure 15 explanation by the CPU54 execution of vehicle control apparatus 52.In Figure 15, the step that those are identical with corresponding steps in the starting control process (Fig. 8) of first embodiment is given identical Reference numeral.Hereinafter, will be omitted or simplify for the unnecessary explanation of identical process, and mainly describe different processes.

In starting control process shown in Figure 15, when the result who judges step S23 for negate the time, CPU54 enters step S42.In step S42, CPU54 judges that being confirmed as beginning certainly institute's elapsed time from the result of step S20 has reached predetermined amount of time Ta.The CPU54 of present embodiment has clocking capability.When the judged result of step S20 is defined as when sure, CPU54 measured from the time of judgement time (being transformed into the time of propulsive effort coupled condition from the propulsive effort off-state) beginning.If the judged result among the step S42 negates that CPU54 enters step S22 and repeats the process that begins from step S22 so.In other words, CPU54 determines engine speed continuously, up to past predetermined amount of time Ta.Section Ta was before the past at the fixed time, and sure if the result of step S23 is confirmed as, CPU54 enters step S24 so, and the program after carrying out.

On the other hand, when the judged result of step S24 when negating, the section Ta rear engine rotating speed M engine speed Ma (driving engine 16 is not raised speed) that can not overstep the extreme limit in the past at the fixed time.In this case, CPU54 finishes the starting control process.After finishing the starting control process, CPU54 resets to zero with the time that records.

In this control, when change-speed box 18 switches to the propulsive effort coupled condition (moment of switching), if engine speed M does not does not meet or exceed limit engine speed M, as engine speed M when section meets or exceeds limit engine speed Ma among the Ta at the fixed time, the starting of vehicle is restricted (propulsive effort is forced to disconnect and engine speed descends) so.

Therefore, except the advantage (1) of first embodiment to (5), the 3rd embodiment also provides following advantage.

(8) at the fixed time the section Ta in, this predetermined amount of time Ta comprises that change-speed box 18 is switched to the time point of propulsive effort coupled condition (instantaneous), engine speed M is monitored.In the section Ta, if engine speed M meets or exceeds limit engine speed Ma, propulsive effort is forced to disconnect so at the fixed time.When chaufeur was transformed into the propulsive effort coupled condition, even chaufeur indication vehicle quickens, engine speed M also may begin to rise to and is equal to or greater than limit engine speed Ma from the moment of conversion.Therefore, begin to determine engine speed M in the past continuously, can avoid not smooth starting more reliably up to predetermined amount of time Ta by be switched to the propulsive effort coupled condition from change-speed box 18.

To Figure 16 the 5th embodiment of the present invention is described below with reference to Figure 14.Present embodiment can be applied in first to the 3rd embodiment any one.

In the present embodiment, when propulsive effort be defined as when the propulsive effort off-state is transformed into the propulsive effort coupled condition (when the judged result of the step S20 of fly start control process for certainly the time), engine speed M is monitored to reach preset vehicle speed up to the speed of a motor vehicle after the time of making judgement.Begin from the time point of making judgement up to the speed of a motor vehicle reach preset vehicle speed during in, if engine speed M meets or exceeds limit engine speed Ma, propulsive effort is forced to disconnect so.Whether in the present embodiment, preset vehicle speed is set at 3krm/h needs to be limited at low speed of a motor vehicle zone so that judge starting.As shown in Figure 14 (d), even acceleration pedal 32 is operated, the speed of a motor vehicle and engine speed are similar, also can not rise fully synchronously along with stepping on action, but rise after a delay.Therefore, when chaufeur conversion pedal, if power-transfer clutch engages with the acceleration pedal 32 that is being operated, the engine speed M when engaging so may be positioned at the low engine speed region that is lower than limit engine speed Ma, and the speed of a motor vehicle also may be positioned at low speed of a motor vehicle zone.In the present embodiment, consider the rising delay of the engine speed M and the speed of a motor vehicle, engine speed M is monitored up to the past predetermined amount of time.

Below, will the starting control process of being carried out by the CPU54 of vehicle control apparatus 52 be described with reference to Figure 16.In Figure 16, those steps identical with corresponding steps in the starting control process (Fig. 8) of first embodiment are endowed identical Reference numeral.Hereinafter, will omit or simplify unnecessary explanation, and mainly describe different processes for identical process.

In the starting control process shown in Figure 16, when the result of determining step S23 when negating, CPU54 enters step S43.In step S43, CPU54 receives the detection signal of car speed sensor 63, and obtains the speed of a motor vehicle.CPU54 receives the detection signal of car speed sensor 63 by the CPU57 of device for controlling engine 53.Subsequently, in step 544, the speed of a motor vehicle (representing with S in Figure 16) that CPU54 will obtain in step S43 is compared with preset vehicle speed (representing with Sa in Figure 14 and 16), and judges that whether speed of a motor vehicle S is more than or equal to preset vehicle speed Sa.If judged result is for negating, the CPU54 process that enters step S22 and repeat to begin so from step S22.In other words, CPU54 determines that continuously engine speed reaches preset vehicle speed Sa up to speed of a motor vehicle S.If before speed of a motor vehicle S arrived preset vehicle speed Sa, the result of step S23 was judged as sure, CPU54 enters step S24 so, and carries out down-stream.

On the other hand, when the judged result of step S44 when negating, even speed of a motor vehicle S has reached preset vehicle speed Sa, the engine speed M engine speed Ma (driving engine 16 does not raise speed) that also can not overstep the extreme limit.In this case, CPU54 finishes the starting control process.

In this control, even (moment of switching) engine speed M does not does not meet or exceed limit engine speed M when change-speed box 18 switches to the propulsive effort coupled condition, as long as engine speed M met or exceeded limit engine speed Ma before the speed of a motor vehicle arrives preset vehicle speed Sa, the starting of vehicle will be subjected to limit value (propulsive effort is forced to disconnect and engine speed descends).

Therefore, except the advantage (1) of first embodiment to (5), present embodiment also provides following advantage.

(9) time point (instantaneous) beginning that is switched to the propulsive effort coupled condition from change-speed box 18 arrives preset vehicle speed Sa up to speed of a motor vehicle S, and engine speed M is monitored.Before speed of a motor vehicle S reached preset vehicle speed Sa, if engine speed M meets or exceeds limit engine speed Ma, propulsive effort was forced to disconnect so.When chaufeur was transformed into the propulsive effort coupled condition, even chaufeur indication vehicle quickens, engine speed M also may begin from the time that is transformed into the rotating speed that is equal to or greater than limit engine speed Ma to rise.Therefore, begin to reach the preset vehicle speed Sa described deterministic process of execution continuously, can avoid not smooth starting more reliably up to speed of a motor vehicle S by be switched to the propulsive effort coupled condition from change-speed box 18.

Below with reference to Fig. 6 and Figure 10 the 6th embodiment of the present invention is described.Present embodiment can be applied in first to the 5th embodiment any one.

In the present embodiment; when load condition in fork truck 10 traveling process changes; and when the limit value content on the vehicular drive (the max speed value and acceleration/deceleration value) changes according to the variation of load condition; execution is used to restrain the control (hereinafter, being called normalisation control) that the speed of a motor vehicle changes (quickening and deceleration) suddenly.The variation of load condition comprise car fork height from high car fork height to low car fork height change situation and the angle of inclination from the scope of receding to exceeding this scope or from exceeding this scope to the situation of change that enters this scope.In the present embodiment, the CPU57 of device for controlling engine 53 carries out described normalisation control.When fork truck 10 was advanced under the situation that acceleration pedal 32 is stepped on fully, the unexpected variation of this speed of a motor vehicle frequently took place.For example, when the restriction state that is restricted when the driving of vehicle was switched to unrestricted unrestricted state, because the restriction that is applied on the max speed or the acceleration/deceleration cancels suddenly, so fork truck 10 may flat-out accelerations and become unstable.Otherwise, when unrestricted state switches to restriction state, because restricted being applied on the max speed or the acceleration/deceleration, so fork truck 10 may slow down and become unstable suddenly.When limiting content loosened, because (that is, the max speed value increases) loosened in the restriction that is applied on the max speed and the acceleration/deceleration, fork truck 10 may the flat-out acceleration and the instability that becomes.

Hereinafter, with the content of explanation by the normalisation control of the CPU57 execution of the device for controlling engine in the present embodiment 53.In the present embodiment, the CPU54 of vehicle control apparatus 52 restriction deterministic process as shown in the execution graph 7 as in the first embodiment.

The CPU57 of device for controlling engine 53 is at memory device 58 stored limiting contents (the max speed value and acceleration/accel/subtract deceleration value), and these limiting contents are by the restricting signal instruction from the CPU54 of vehicle control apparatus 52.During this time, CPU57 stores in memory device 58 by the limiting content of the restricting signal instruction that receives in last control cycle and the limiting content that is instructed by the restricting signal that receives in current control cycle.CPU57 will be stored in the limiting content of the last control cycle in the memory device 58 and compare with the limiting content of current control cycle, and determine whether change on described content.Particularly, CPU57 determines that whether limiting content changes in response to the variation of car fork height, and whether definite limiting content changes in response to the variation at angle of inclination.The variation that limiting content produces in response to car fork height change comprises variation (hereinafter, being called variation pattern P1) and the variation from restriction state to unrestricted state (hereinafter, being called variation pattern P2) from unrestricted state to restriction state.The variation that limiting content produces in response to angle change comprises that variation that the max speed value and acceleration/deceleration value produce from the scope of receding to the variation that exceeds this scope in response to the angle of inclination (hereinafter, be called variation pattern P3), with the max speed value and acceleration/deceleration value in response to the angle of inclination from exceeding the variation (hereinafter, being called variation pattern P4) that the described scope that recedes produces to the variation that enters the described scope that recedes.

Then, if the limiting content that is applied on the vehicular drive does not change, CPU57 regulates engine speed according to the limiting content of current control cycle so, controls driving engine 16 thus.Particularly, when the driving of vehicle was unrestricted, CPU57 regulated engine speed thus according to detection signal (depression amount of acceleration pedal 32) the control throttle valve drive device 35 that is arranged on the accelerator pedal position sensor 70 on the acceleration pedal 32.When the driving of vehicle was restricted, CPU57 adopted the engine speed shown in Figure 10 to regulate data adjusting engine speed based on the max speed value and the acceleration/deceleration value that are stored in the memory device 58.

On the other hand, when the limiting content on being applied to vehicular drive had changed, CPU57 determined that in the P4 which of described variation and variation pattern P1 conforms to.CPU57 controls driving engine 16 thus according to being that the predetermined control that every kind of variation pattern is set is regulated engine speed then.If described variation conforms to variation pattern P1, CPU57 adopts the max speed value by the restricting signal instruction as the max speed value so, and adopt acceleration/deceleration grade 1 instead by the acceleration/deceleration value (acceleration/deceleration grade) of restricting signal instruction as the acceleration/deceleration value.For example, even restricting signal instruction the max speed value is that 15km/h and acceleration/deceleration grade are 4, CPU57 adopts acceleration/deceleration grade 1 to carry out control.If described variation conforms to variation pattern P2, the restriction (do not limit the max speed value) of CPU57 cancellation on the max speed value so, and continue to adopt acceleration/deceleration grade 1 as the acceleration/deceleration value.

If described variation conforms to variation pattern P3, CPU57 adopts by the max speed value and the acceleration/deceleration value of restricting signal instruction and carries out control so.If described variation conforms to variation pattern P4, CPU57 adopts the max speed value of being instructed by restricting signal as the max speed value so, and adopts the acceleration/deceleration grade than low one grade of the acceleration/deceleration value (acceleration/deceleration grade) of being instructed by restricting signal.For example, at the limiting content of last control cycle is under the situation of the max speed value of 12km/h and acceleration/deceleration grade 3, if the limiting content of current control cycle is the max speed value and the acceleration/deceleration class 4 of 15km/h, CPU57 adopts the max speed value and the acceleration/deceleration grade 3 of 15km/h so.

When limiting the acceleration/deceleration grade according to above-described normalisation control (when the acceleration/deceleration grade has changed), CPU57 is set to normal level according to serviceability degree of the will speed up/deceleration/decel grade of acceleration pedal 32.In other words, whether the ON operation of CPU57 monitoring acceleration pedal 32 switches to the OFF operation.When the ON operation that detects acceleration pedal 32 had switched to the OFF operation, CPU57 degree of will speed up/deceleration/decel grade reverted to last grade.More particularly, if described variation conforms to variation pattern P1, CPU57 will revert to the acceleration/deceleration value (acceleration/deceleration grade) of being instructed by restricting signal with acceleration/deceleration grade 1 relevant acceleration/deceleration value so.When described variation conformed to variation pattern P2, CPU57 cancelled the qualification to the acceleration/deceleration grade, and does not limit acceleration/deceleration.When described variation conformed to variation pattern P3, because CPU57 does not also change the acceleration/deceleration grade, so CPU57 kept current state.If described variation conforms to variation pattern P4, CPU57 degree of will speed up/deceleration value reverts to the acceleration/deceleration value (acceleration/deceleration grade) by the restricting signal instruction so.

Therefore, except that the advantage (1) of first embodiment to (5), present embodiment also provides following advantage.

(10) when the limiting content in the driving that is applied to vehicle changes, select the acceleration/deceleration grade according to the degree that changes, and therefore carry out drive controlling.Therefore, when limiting content changes, prevented speed of a motor vehicle flip-flop.In other words, when limiting content changed, fork truck 10 was slowly quickened or is slowed down.Consequently, when limiting content changes, prevent the driving instability of fork truck 10.In other words, fork truck 10 can be driven in the pulsation-free mode.By carrying out the normalisation control of present embodiment, fork truck 10 startings and the stability when advancing all can be guaranteed.Further, in fork truck 10 traveling process, the stability of fork truck 10 is guaranteed that this stability is not just obtainable by controlling the max speed and acceleration/deceleration simply.When the drive condition of fork truck 10 changed, chaufeur had time enough recollectedly to handle this change.

(11) in normalisation control, when chaufeur was carried out the OFF operation of acceleration pedal 32, the acceleration/deceleration grade was resumed and is normal level (with load condition relevant acceleration/deceleration/decel grade).Therefore, need not to make the operation of chaufeur to complicate, be cancelled by the restriction (setting of acceleration/deceleration grade) on the normalisation control fork truck 10.

17 to 20 the 7th embodiment of the present invention is described below with reference to the accompanying drawings.In ensuing embodiment, described to such an extent that the explanation of same parts of embodiment will omit or simplify.

In aforementioned embodiments, be assumed to and on the level land, carry out starting, do not consider the climbing starting.In other words, when execution prevents the control of fly start, the decline of detection of engine rotating speed reaches the grade that is equal to or less than a particular value (cancellation limiting engine rotating speed Mb), and allows fork truck to advance by cancellation propulsive effort off-state and engine retard state of a control.Yet,, on the level land, start so and will have problems if cancellation limiting engine rotating speed Mb sets higherly to prevent that the back slips on uphill road.In other words, as shown in Figure 17, preventing that fly start is controlled at engine speed is after the time t0 place of limit engine speed Ma begins, when prevent that fly start is controlled at time t1 place that engine speed drops to cancellation limiting engine rotating speed Mb when finishing, and the back slide can not take place on uphill road.Yet fork truck 10 will be by fly start on the level land.If cancellation limiting engine rotating speed Mb is set lowly to prevent fly start on the level land, on uphill road, starts so and will have problems.In other words, as shown in Figure 18, preventing that fly start is controlled at engine speed is after the time t0 place of limit engine speed Ma begins, when preventing that fly start is controlled at engine speed when dropping to the time t1 place end of cancellation limiting engine rotating speed Mb, will fly start can not take place on the level land.Yet fork truck 10 slips the back on uphill road.Present embodiment has prevented to slip and fly start on the level land in back on the uphill road simultaneously.

Except limit engine speed Ma and cancellation limiting engine rotating speed Mb, also store engine retard cancellation rotating speed Mc in the memory device 55 of vehicle control apparatus 52.Engine retard cancellation rotating speed Mc is set at less than (being lower than) cancellation limiting engine rotating speed Mb.Cancellation limiting engine rotating speed Mb is set at and is higher than an engine speed, and this engine speed can not cause fork truck 10 fly start on the level land, and engine retard cancellation rotating speed Mc is set at and is lower than described cancellation limiting engine rotating speed Mb.Cancellation limiting engine rotating speed Mb and engine retard cancellation rotating speed Mc are after having considered load condition (limiting content in the driving process), the value that the experiment (simulation) of the reduction degree of the engine speed of the stationarity when keeping vehicle launch by being used to find out obtains.Therefore, cancellation limiting engine rotating speed Mb and engine retard cancellation rotating speed Mc is according to the type of fork truck 10 and variant.In the present embodiment, for example, limit engine speed Ma is 1700rpm, and cancellation limiting engine rotating speed Mb is 1500rpm, and engine retard cancellation rotating speed Mc is 1200rpm.

The CPU54 of controller of vehicle 52 carries out the process identical with the step S23 of aforementioned embodiments in the starting control process.Memory device 55 storages are used to carry out the control program of the diagram of circuit shown in Figure 19.In described diagram of circuit, identical among the above part of step S24 and Fig. 8, wherein a part is omitted.

19 starting process of describing present embodiment below with reference to the accompanying drawings.In Figure 19, give identical Reference numeral to those steps identical with corresponding steps in the starting control process (Fig. 8) of first embodiment.Hereinafter, will omit or simplify unnecessary explanation, and mainly describe different processes for identical process.

In the starting control process shown in Figure 19, when the judged result of step S23 for certainly the time, in step S24, the CPU54 of vehicle control apparatus 52 determines that the acceleration/deceleration grade is [1] or [2].If the judged result among the step S24 is sure, CPU54 forces to disconnect propulsive effort in step S25 so.In step S25, as in the first embodiment, CPU54 controls and advances electromagnetic valve 44 and retreat electromagnetic valve 45, disconnects propulsive effort thus.After step S25 broke propulsive effort, CPU54 carried out the engine retard process.In other words, in step S30, CPU54 carries out racing of the engine request (reducing the request of driving engine 16 rotating speeds).When receiving the racing of the engine request signal from CPU54, CPU57 controls throttle controller 35, regulates the rotating speed of driving engine 16 thus.Do not consider the testing result (depression amount of acceleration pedal 32) of accelerator pedal position sensor 70, CPU57 control driving engine 16 is to reduce engine speed.

After step S30, in step S31, CPU54 obtains engine speed.Then, the engine speed (representing with M in Figure 19) that CPU54 will obtain in step S32 is compared with predetermined cancellation limiting engine rotating speed (representing with Mb in Figure 19), and whether definite engine speed M is less than or equal to cancellation limiting engine rotating speed Mb.Cancellation limiting engine rotating speed Mb is set at less than limit engine speed Ma.In the present embodiment, cancellation limiting engine rotating speed Mb is set at 1500rpm.If the judged result among the step S32 is (Mb＜M), the CPU54 process that enters step S31 and repeat to begin from step S31 so of negating.On the other hand, if the judged result among the step S32 is that sure (Mb 〉=M), CPU54 enters step S27 so.In step S27, the off-state of CPU54 cancellation propulsive effort inserts propulsive effort thus again.In step S27, identical with the fwd embodiment, CPU54 controls and advances electromagnetic valve 44 or retreat electromagnetic valve 45, inserts propulsive effort thus again.

In the first embodiment, (Mb 〉=M), CPU54 finishes moderating process to insert propulsive effort again for certainly the time when the judged result of step S32.On the contrary, in the present embodiment, CPU54 continues moderating process.After step S27, CPU54 enters step S51.In step S51, CPU54 obtains engine speed.Then, the engine speed (representing with M in Figure 19) that CPU54 will obtain in step S52 is compared with predetermined engine retard cancellation rotating speed (representing with Mc in Figure 19), and whether definite engine speed M is less than or equal to engine retard cancellation rotating speed Mc.

If the judged result of step S52 is (Mc＜M), the CPU54 process that enters step S51 and repeat to begin from step S51 so of negating.On the other hand, if the judged result among the step S52 is that sure (Mc 〉=M), CPU54 enters step S53 and cancellation engine retard process status so.In other words, CPU54 finishes the engine retard process.After step S53, CPU54 finishes the starting control process.

Consequently, when propulsive effort disconnection and engine retard control were cancelled in preventing fly start control, the velocity variations of fork truck 10 was represented by Figure 20.In other words, when fork truck 10 starts on the level land, be disconnected at the time t0 propulsive effort.After this, engine speed is reduced to cancellation limiting engine rotating speed Mb.At time t1, propulsive effort disconnected and to be cancelled this moment, and fork truck 10 is not being that the speed of fly start is started.After this, engine speed drops to engine retard cancellation rotating speed Mc, and is cancelled in the control of time t3 engine retard.Since time t3, the speed of a motor vehicle increases with bigger acceleration/accel.

When going up a slope starting, engine speed is reduced to cancellation limiting engine rotating speed Mb, and begins to advance at time t2 fork truck 10, and time t2 is a certain hour section after the open circuited cancellation of propulsive effort time t1.In other words, fork truck 10 is compared on the time that postpones with the level land starting and is started.After this, engine speed is reduced to engine retard cancellation rotating speed Mc, and is cancelled in the control of time t3 engine retard.After time t3, the speed of a motor vehicle rises gradually with the acceleration/accel less than level land starting situation.

Except the advantage (1) of first embodiment to (5), present embodiment also provides following advantage.

(12) when disconnecting control part (CPU54) and disconnect propulsive effort, motor speed control part (CPU54) drops to engine speed to be lower than cancellation limiting engine rotating speed Mb, and this rotating speed Mb is lower than limit engine speed Ma.When disconnecting propulsive effort, when engine speed is reduced to cancellation limiting engine rotating speed Mb, disconnect the disconnection of control part cancellation propulsive effort, but continue engine retard control.When engine speed drops to or be lower than than the low engine retard cancellation rotating speed Mc of cancellation limiting engine rotating speed Mb, the control of motor speed control partial cancellation engine retard.Therefore, be higher than an engine speed that can not cause fork truck 10 fly starts even cancellation limiting engine rotating speed Mb is set at, on the level land, also can prevent fork truck 10 with the corresponding speed fly start of cancellation limiting engine rotating speed Mb.And, can prevent that the back slips on the hillside.

21 to 23 the 8th embodiment of the present invention is described below with reference to the accompanying drawings.The place that present embodiment greatly is different from the 7th embodiment is, in preventing fly start control (starting control), the cancellation open circuited condition of propulsive effort (factor) comprises the speed of a motor vehicle rather than the engine speed of fork truck 10, and when the propulsive effort disconnection was cancelled, the engine retard state of a control was cancelled at one time.Except above-mentioned difference, the 8th embodiment is identical in the 7th embodiment, and will omit or simplify the explanation for the same parts of the embodiment of having described.

The CPU54 of vehicle control apparatus 52 carries out the identical process before the step S25 in the starting control process.Memory device 55 storages are used to carry out the control program of the diagram of circuit shown in Figure 21.In described diagram of circuit, identical among the part before the step S25 and Figure 19, and wherein part is omitted.

As in the 7th embodiment, in step S25, CPU54 disconnects propulsive effort.After step S25 broke propulsive effort, CPU54 received the detection signal of car speed sensor 63, and obtains the speed of a motor vehicle.CPU54 receives the detection signal of car speed sensor 63 by the CPU57 of device for controlling engine 53.Subsequently, in step S56, the speed of a motor vehicle (representing with S in Figure 21) that CPU54 will obtain in step S55 is compared with cancellation restricted speed (representing with Sb in Figure 21), and whether definite speed of a motor vehicle S is more than or equal to cancellation restricted speed Sb.If judged result is that sure (S 〉=Sb), CPU54 enters step S27 so.In step S27, CPU54 cancellation propulsive effort off-state inserts propulsive effort thus again.Identical with the fwd embodiment, in step S27, CPU54 controls and advances electromagnetic valve 44 or retreat electromagnetic valve 45, inserts propulsive effort thus again.

On the other hand, if the judged result of step S56 be negate (S＜Sb), CPU54 enters step S57 and obtains engine speed so.Then, the engine speed (representing with M in Figure 21) that CPU54 will obtain in step S57 is compared with predetermined cancellation limiting engine rotating speed (representing with Mb in Figure 21), and whether definite engine speed M is less than or equal to cancellation limiting engine rotating speed Mb.Cancellation limiting engine rotating speed Mb is the value that is lower than limit engine speed Ma, can not cause fork truck 10 fly starts on the level land.In the present embodiment, cancellation limiting engine rotating speed Mb is set at 1500rpm.

If the judged result among the step S58 be negate (Mb＜M), CPU54 enters step S55 so, and repeats the process that begins from step S55.Another reverse side is if the judged result among the step S58 is that sure (Mb 〉=M), CPU54 enters step S27 so.In step S27, CPU54 cancellation propulsive effort off-state inserts propulsive effort thus again.

Consequently, when preventing that fly start is controlled at when carrying out on the mild sloping road, because the disconnection of propulsive effort is represented by Figure 22 with the velocity variations that is connected the fork truck 10 that causes.In other words, after the time t0 propulsive effort disconnected, engine speed reduced and fork truck 10 backs slip.At time t11, when the speed of a motor vehicle became cancellation restricted speed Sb, propulsive effort disconnected and being cancelled.Therefore fork truck 10 startings.The result has prevented back slide.

Consequently, when preventing that fly start is controlled at when carrying out on the precipitous sloping road, because the disconnection of propulsive effort is represented by Figure 23 with the velocity variations that is connected the fork truck 10 that causes.In other words, after the time t0 propulsive effort disconnected, engine speed reduced and fork truck 10 backs slip.At time t11, when the speed of a motor vehicle became cancellation restricted speed Sb, propulsive effort disconnected and being cancelled.Therefore fork truck 10 startings.In this case, shortened because the back slips the speed of a motor vehicle of fork truck 10 and drops to or be lower than time of cancellation restricted speed Sb, and the situation when engine speed is higher than mild sloping road during time t11.Reduced the amount that fork truck 10 backs slip.

And, when starting on the level land, the back does not take place slips.Therefore, if propulsive effort is disconnected, the speed of a motor vehicle of fork truck 10 can not reach cancellation restricted speed Sb so, is cancelled up to disconnection.Therefore, the disconnection of propulsive effort can not be cancelled based on speed of a motor vehicle S.When engine speed M dropped to or be lower than cancellation limiting engine rotating speed Mb, the disconnection of propulsive effort was cancelled, and propulsive effort is inserted again.Because cancellation limiting engine rotating speed Mb is set at a value that can not cause fork truck 10 fly starts on the level land, therefore can prevent fork truck 10 fly starts.

Except the advantage (1) of first embodiment to (5), present embodiment also provides following advantage.

(13) under the situation that disconnects control part (CPU54) pressure disconnection propulsive effort, when the speed of a motor vehicle meets or exceeds predetermined cancellation restricted speed Sb, or when engine speed dropped to or be lower than than the low cancellation limiting engine rotating speed Mb of limit engine speed, the disconnection of propulsive effort was cancelled.Therefore,, also can eliminate the back slide when starting, and prevent the fly start on the level land even on precipitous sloping road.Therefore fork truck 10 starts in the pulsation-free mode.And in the open circuited while of cancellation propulsive effort, engine retard control finishes.Therefore, than the end of carrying out open circuited cancellation of propulsive effort and engine retard control according to different conditions, control process obtains simplifying.

Above-mentioned embodiment can carry out following change.

Although described embodiment is applied on the fork truck 10 (tor-con vehicle) of tor-con type, yet the present invention also can be used on the fork truck (power-transfer clutch vehicle) or hydrostatic drive vehicle (HST vehicle) of clutch type.Under the situation of MT vehicle, for example, as in said embodiment, the power-transfer clutch that forms transmission system is converted to released state from engagement state in disconnecting control, forces to disconnect the transmission of propulsive effort thus.Under the situation of HST vehicle, for example, in disconnecting control, form the Hydraulic Pump of transmission system and the fluid power passage between the HM Hydraulic Motor by disconnection, the transmission of propulsive effort is forced to disconnect.

In described embodiment, be used for definite the max speed and acceleration/deceleration and whether answer confined parameter, and the calculating of the max speed and acceleration/deceleration can be changed.For example, can set mapping relations carrying out described deterministic process based on car fork height and load weight, and calculating the max speed and acceleration/deceleration.In the necessary determination data shown in Fig. 4, the zone of car fork height and load weight can be divided into littler zone so that two or more restricted areass to be provided.In this case, for each restricted areas provides the acceleration/deceleration computational data shown in the speed of a motor vehicle computational data shown in Fig. 5 and Fig. 6, thereby make that for each restricted areas the data that are used to calculate the max speed value and acceleration/deceleration value change.When partition cart fork height regional, strut assemblies 19 can have two or more limit switches with inspection vehicle fork height.Perhaps, strut assemblies 19 can have reel sensor (reer sensor) with continuous detecting car fork height.

In described embodiment, can be configured to when feeding solenoidal electric current when being zero, the electromagnetic valve 44 and retreat electromagnetic valve 45 and close fully of advancing, and when electric current feeding spiral tube, all open.

In described embodiment, forward relay circuit 60 and reverse relay circuit 61 can be formed rather than be formed by normally closed contactor by normally open contactor.Adopting under the situation of normally open contactor, electromagnetic valve 44 and retreat electromagnetic valve 45 energising when normally open contactor is closed, outage when contactless switch is opened advances.

In described embodiment, the structure of forward clutch 42 and back clutch 43 can change.In other words, the increase that can be configured to the clutch pressure among each pressure receiving cavity 42a, 43a increases engaging force, and the reduction of clutch pressure reduces engaging force.

In described embodiment, can provide hydraulic oil with march forward power-transfer clutch 42 and back clutch 43 for feed path provides bypass.In this case, when force disconnecting propulsive effort, can supply with hydraulic oil via march forward power-transfer clutch 42 or back clutch 43 of described bypass by switching described feed path.And, increasing in the structure of engaging force by the clutch pressure that increases forward clutch 42 and back clutch 43, can force to disconnect the stream that propulsive effort is used to switch hydraulic oil by stopping up feed path.

Described embodiment can be set to, and detects the speed of a motor vehicle when the propulsive effort off-state is converted to the propulsive effort coupled condition, and when the speed of a motor vehicle that records is equal to or less than the predetermined threshold speed of a motor vehicle, carries out motor speed control and disconnect control.The threshold value speed of a motor vehicle is set at for example 3km/h that is in the low speed of a motor vehicle zone in this case.According to this set, if carry out an operation to disconnect or to insert propulsive effort in fork truck 10 is advanced (at high speed) process, motor speed control and disconnection control are not carried out so.This has guaranteed the stability that drives.In other words, only when fork truck 10 starts, can carry out motor speed control and disconnect control, thereby instability appears in the feasible vehicle of avoiding in traveling process.

In described embodiment, when the restriction acceleration/deceleration, the CPU54 of vehicle control apparatus 52 can send the signal of an indication acceleration/deceleration grade rather than limited acceleration/deceleration value to device for controlling engine 53.

In described embodiment, the engine speed that uses in the starting control process can calculate based on the detected value of accelerator pedal position or throttle opening.Can adopt accelerator pedal position or throttle opening rather than engine speed to carry out described process.In this case,, also can carry out described control, adopt minimum required sensor (test section) to be used for engine control by detecting accelerator pedal position and throttle opening even fork truck 10 is not equipped with engine speed sensor 62.

In the first embodiment, when load condition is very harsh (in the first embodiment, when the acceleration/deceleration grade is [1] or [2]), propulsive effort is disconnected and engine speed reduces.When the driving of automobile such as the max speed and acceleration/deceleration need be restricted, disconnect propulsive effort and can not consider that the mode that load condition reduces engine speed replace above-mentioned control thereby can adopt.

First embodiment can be set to, and when load condition is very harsh, disconnects propulsive effort and reduce engine speed, and under other condition, fork truck 10 can need not to carry out motor speed control and start with disconnecting control.For example, in the first embodiment, even acceleration/deceleration grade [3] or [4] corresponding to the state of fork truck 10 bearing loads, as long as load condition allows fork truck 10 smooth startings, also need not to be provided with restriction when starting.

In the first embodiment, when propulsive effort is forced to disconnect, according to engine speed M drop to or be lower than the cancellation limiting engine required time of rotating speed Mb, propulsive effort can be inserted again.This described time can be passed through analogue computing.In the first embodiment, when propulsive effort is forced to disconnect, engine speed drops to or the required time that is lower than cancellation limiting engine rotating speed Mb can calculate by the engine speed when disconnecting, and after required time was gone over, propulsive effort can be inserted again.For example, under the situation of engine speed M1, after time period T1 went over, propulsive effort was inserted again.Engine speed M2 (under the situation of M2＜M1), when time period T2 in the past after, propulsive effort is inserted again.In this set, when engine speed was in the high rotary speed area, the propulsive effort off-state was cancelled gradually.On the other hand, when engine speed was in the low rotation speed area, the propulsive effort off-state was by immediate cancel.Therefore, the driving of fork truck 10 stability and operability can both be guaranteed.

In the first embodiment, the mapping (enum) data (engine speed adjusting data) that is used for regulating engine speed is stored in memory device 58.Yet CPU57 can adopt predetermined mathematic(al) representation calculation engine speed adjustment amount based on the information that sends to CPU57 (the max speed value, acceleration/deceleration value and the speed of a motor vehicle), thereby replaces with reference to mapping (enum) data.

At first, second, in the 4th, the 5th and the 6th embodiment, can judge whether the propulsive effort off-state has been transformed into the propulsive effort coupled condition based on the operation of forward/back control lever 31 or brake pedal 34.Carrying out based on the operation of forward/back control lever 31 under the situation of described judgement, when forward/back control lever 31 when Neutral Position [N] switches to progressive position [F] or going-back position [R], can determine that the propulsive effort off-state has switched to the propulsive effort coupled condition.Carrying out based on the operation of brake pedal 34 under the situation of described judgement, when the ON of brake pedal 34 operation switches to the OFF operation, can determine that the propulsive effort off-state has switched to the propulsive effort coupled condition.At first, second, in the 4th, the 5th and the 6th embodiment, carry out described judgement based on the operation of slow-action pedal 33.Yet, can carry out described judgement based on the operation of the combination in any in slow-action pedal 33, forward/back control lever 31 and the brake pedal 34.For example, when forward/back control lever 31 switches on progressive position [F] or the going-back position [R] from Neutral Position [N], and the OFF of slow-action pedal 33 operation can determine that the propulsive effort off-state has switched to the propulsive effort coupled condition when switching to the ON operation.

At first, second, in the 4th, the 5th and the 6th embodiment, can detect the depression amount (pedal stroke amount) of slow-action pedal 33, and the joint that can detect power-transfer clutch based on described testing result with separate.

In second embodiment, when propulsive effort was forced to disconnect, when engine speed M dropped to or be lower than cancellation limiting engine rotating speed Mb, propulsive effort can be inserted again.In second embodiment, when propulsive effort was forced to disconnect, vehicle control apparatus 52 did not send the no-load speed request to device for controlling engine 53.Therefore, in order to reduce engine speed, chaufeur need be carried out the OFF operation of acceleration pedal 32.Therefore, engine speed reduces.

In second embodiment, after propulsive effort was forced to disconnect, when chaufeur switched to the propulsive effort off-state with the propulsive effort coupled condition, propulsive effort can be inserted again.In this case, chaufeur need be carried out the ON operation of slow-action pedal 33, perhaps forward/back control lever 31 is switched to Neutral Position [N].

In the 3rd embodiment, connection judgment value and disconnection judgment value can merge.

Predetermined amount of time Ta in the 5th embodiment and the preset vehicle speed Sa in the 6th embodiment can change.

In the 6th embodiment, can change selected acceleration/deceleration grade when limiting content changes.In other words, for fear of flat-out acceleration or deceleration, the acceleration/deceleration grade that has reduced acceleration/deceleration is compared in selection with normal level.

The 6th embodiment can be set to, and the CPU54 of vehicle control apparatus 52 judges whether limiting content changes, and according to described judged result, CPU54 specifies the max speed value and acceleration/deceleration value to the CPU57 of device for controlling engine 53.CPU57 carries out control according to described instruction.

In the 7th embodiment, when disconnecting propulsive effort, be not when engine speed drops to or be lower than cancellation limiting engine rotating speed M, but cancel the required time period past tense of engine speed Mb when engine speed drops to or is lower than restriction, CPU54 can cancel the disconnection of propulsive effort.The described time period is (simulation) acquisition in advance by experiment.And, also can be arranged to, not when engine speed drops to or be lower than engine retard cancellation rotating speed Mc, but, engine speed cancels the required time period past tense of rotating speed Mc, the engine retard state of a control that cancellation (termination) is partly implemented by motor speed control when dropping to or be lower than engine retard.

In the 7th embodiment, when engine speed decline is less than or equal to the value of cancellation limiting engine rotating speed Mb, perhaps drop to or be lower than the required time past tense of restriction cancellation engine speed Mb when engine speed, the condition that is used to cancel the propulsive effort off-state is satisfied.

In the 8th embodiment, when disconnecting propulsive effort, be not when engine speed drops to or be lower than cancellation limiting engine rotating speed M, but cancel the required time period past tense of engine speed Mb when engine speed drops to or is lower than restriction, CPU54 can cancel the disconnection of propulsive effort.

In the 7th embodiment, when CPU54 disconnected propulsive effort, the open circuited condition of cancellation propulsive effort can comprise that the speed of a motor vehicle is more than or equal to cancellation restricted speed Sb.In other words, when engine speed is reduced to or be lower than cancellation limiting engine rotating speed Mb, or when the speed of a motor vehicle met or exceeded cancellation restricted speed Sb, CPU54 can cancel the disconnection of propulsive effort.In this case, even fork truck 10 is positioned on the unaccommodated slope of cancellation limiting engine rotating speed Mb, the starting control program also can be carried out smoothly.

The solenoidal magnitude of current that leads to forward clutch 42 and back clutch 43 can be regulated, thereby makes described power-transfer clutch set Be Controlled according to three kinds, and described three kinds of settings are released state (released state), partial engagement state and full engagement state.In the 7th embodiment, when cancelling the disconnection of propulsive effort, propulsive effort can be transmitted by the power-transfer clutch of partial engagement.In this case, when engine speed is reduced to or be lower than engine retard cancellation rotating speed Mc, the power-transfer clutch full engagement.

In described embodiment, load condition when switching to the propulsive effort coupled condition based on the propulsive effort off-state and engine speed are carried out the control of forcing to disconnect propulsive effort.Yet described control can be based on a kind of being performed in load condition and the engine speed.For example, if the load condition when changing from the propulsive effort off-state to the propulsive effort coupled condition needs the driving of vehicle to be restricted, propulsive effort is forced to disconnect so.In other words, even the rotation of driving engine 16 is not accelerated when playing electrical forklift 10, so described starting also may be owing to load condition becomes unstable, the car fork height that described load condition is for example higher.Therefore, by force disconnecting propulsive effort, can prevent that vehicle from starting may causing driving under the unsettled situation according to load condition.By disconnecting described propulsive effort, impel chaufeur to change load condition (for example, reducing car fork height).And, because fork truck 10 load runnings, thereby when fork truck 10 startings, must very careful described operation can not become unstable.Therefore, even load condition is corresponding with low car fork height and underload, if the rotation quickening of driving engine 16 when starting, fork truck 10 also can fly start, and this may cause fluctuation of service.Therefore, by force disconnecting propulsive effort, can prevent that vehicle from starting may causing driving under the unsettled situation according to engine speed.By disconnecting propulsive effort, impel chaufeur to change the serviceability (for example, reducing depression amount) of acceleration pedal 32.

Claims (11)

1. drive control apparatus (52,53) that is used for fork truck (10),

Wherein, fork truck (10) comprises car body (11), it is anterior and load the bogey (22) of load to be positioned at drive wheel (14), driving engine (16) on the car body (11), to be arranged in the Poewr transmission mechanism (18) between driving engine (16) and the drive wheel (14) and to be positioned at car body (11), and

Described Poewr transmission mechanism (18) can given driving engine (16) transmission of power the coupled condition of drive wheel (14) and driving engine (16) transmission of power do not switched between the off-state of drive wheel (14), wherein, fork truck (10) utilizes the power of driving engine (16) to advance as propulsive effort, and described drive control apparatus is characterised in that:

Connect determining section (54, S20), determine that whether Poewr transmission mechanism (18) switches to coupled condition in response to the operation of chaufeur from off-state;

The load determining section (54, S10), determine and the relevant load condition of bogey (22);

Disconnect control part (54, S25), wherein, connect determining section (54, S20) determine to switch under the situation of coupled condition (S20), if by load determining section (54, S10) load condition of Que Dinging needs the driving of car body (11) to be restricted (S12, S21), (54, S25) pressure disconnects the transmission of propulsive effort to drive wheel (14) to disconnect control part so.

2. drive control apparatus according to claim 1 is characterized in that, determine engine speed the engine speed determining section (54, S22), wherein limit engine speed is set to the speed without load that is higher than driving engine (16) at least,

Wherein, connecting determining section (54, S20) determine to switch under the situation of coupled condition (S20), if by the load determining section (54, S10) definite load condition need the driving of car body (11) be restricted (S12, S21), and by engine speed determining section (54, S22) engine speed of Que Dinging is equal to or greater than limit engine speed (S23), and (54, S25) pressure disconnects the transmission of propulsive effort to drive wheel (14) to disconnect control part so.

3. drive control apparatus that is used for fork truck (10), wherein, fork truck (10) comprises car body (11), it is anterior and load the bogey (22) of load to be positioned at drive wheel (14), driving engine (16) on the car body (11), to be arranged in the Poewr transmission mechanism (18) between driving engine (16) and the drive wheel (14) and to be positioned at car body (11)

Wherein, described Poewr transmission mechanism (18) can given driving engine (16) transmission of power the coupled condition of drive wheel (14) and driving engine (16) transmission of power do not switched between the off-state of drive wheel (14), wherein, fork truck (10) utilizes the power of driving engine (16) to advance as propulsive effort, and described drive control apparatus is characterised in that:

Connect determining section (54, S20), determine that whether Poewr transmission mechanism (18) switches to coupled condition in response to the operation of chaufeur from off-state;

The engine speed determining section (54, S22), be used for determining the rotating speed of driving engine, wherein limit engine speed is set to the speed without load that is higher than driving engine (16) at least;

Disconnect control part (54, S25), wherein, connecting determining section (54, S20) determine to switch under the situation of coupled condition, if (54, S22) definite engine speed is equal to or greater than limit engine speed by the engine speed determining section, (54, S25) pressure disconnects the transmission of propulsive effort to drive wheel (14) to disconnect control part so.

4. according to claim 2 or 3 described drive control apparatus,

It is characterized in that cancellation limiting engine rotating speed is set to and is lower than limit engine speed,

Wherein, drive control apparatus also comprises motor speed control part (54,57, S26, S28), when disconnecting control part (54, when S25) disconnecting propulsive effort, described motor speed control part (54,57, S26 S28) drops to engine speed or is lower than cancellation limiting engine rotating speed, wherein, described motor speed control part (54,57, S26, S28) engine speed is dropped to or be lower than cancellation limiting engine rotating speed and need a preset time section (t1), and

Wherein, when engine speed drops to or be lower than cancellation limiting engine rotating speed (S32), or when described preset time section (t1) past tense, the pressure that disconnects control part (54) cancellation propulsive effort disconnects (S27).

5. according to claim 2 or 3 described drive control apparatus,

It is characterized in that fork truck (10) also comprises the accelerating part (32) that instruction car body (11) quickens, cancellation limiting engine rotating speed is set to and is lower than limit engine speed, and,

Wherein, when following any one situation took place, the pressure that disconnects control part (54) cancellation propulsive effort disconnected (S27):

Not instructing after car body (11) quickens, the ON operation of accelerating part (32) is performed with instruction once more and quickens in OFF operation that chaufeur is carried out accelerating part (32); Engine speed drops to or is lower than cancels limiting engine rotating speed (S32); And in response to the operation of chaufeur, coupled condition switches to off-state (S25).

6. according to claim 2 or 3 described drive control apparatus,

It is characterized in that cancellation limiting engine rotating speed is set to and is lower than limit engine speed, and engine retard cancellation rotating speed is set to and is lower than cancellation limiting engine rotating speed,

Wherein, drive control apparatus also comprises motor speed control part (54,57, S30), when disconnecting control part (54) disconnection propulsive effort, described motor speed control part (54,57, S30) engine speed is dropped to or be lower than cancellation limiting engine rotating speed, wherein, described motor speed control part (54,57, S30) engine speed is dropped to or be lower than cancellation limiting engine rotating speed and need first predetermined amount of time (t1), and motor speed control part (54,57, S30) engine speed is dropped to or be lower than engine retard cancellation rotating speed and need second predetermined amount of time (t3)

Wherein, when engine speed drops to or be lower than cancellation limiting engine rotating speed (S32), or when described first predetermined amount of time (t1) past tense, the pressure that disconnects control part (54) cancellation propulsive effort disconnects (S27) under off-state, and

Wherein, when engine speed drops to or be lower than engine retard cancellation rotating speed, or, disconnect control part (54) by motor speed control part (54 when described second predetermined amount of time (t3) past tense, 57, S30) cancellation engine retard control (S53).

7. according to claim 2 or 3 described drive control apparatus,

It is characterized in that cancellation limiting engine rotating speed is set to and is lower than limit engine speed,

Wherein, when the speed of a motor vehicle when off-state is issued to or surpass predetermined cancellation restricted speed (S56), or when engine speed drops to or be lower than cancellation limiting engine rotating speed (S58), disconnect the pressure disconnection (S27) of control part (54) cancellation propulsive effort.

8. according to claim 2 or 3 described drive control apparatus,

It is characterized in that, connecting determining section (54, S20) determine to switch under the situation of coupled condition, if lighting preset time section (Ta) before the past from switching the time of determining, by engine speed determining section (54, S22) engine speed of Que Dinging meets or exceeds limit engine speed, disconnects the transmission (S25) that control part (54) forces to disconnect propulsive effort so.

9. according to claim 2 or 3 described drive control apparatus,

It is characterized in that, connecting determining section (54, S20) determine to switch under the situation of coupled condition, if lighted before the speed of a motor vehicle arrives preset vehicle speed from switching the time of determining, by engine speed determining section (54, S22) engine speed of Que Dinging meets or exceeds limit engine speed, disconnects the transmission (S25) that control part (54) forces to disconnect propulsive effort so.

10. according to claim 1 or 3 described drive control apparatus,

It is characterized in that described Poewr transmission mechanism (18) comprises power-transfer clutch (42,43),

Wherein, car body (11) also comprises the driving command part (31) in response to the driving direction of the operating order car body (11) of chaufeur, continuously change power-transfer clutch (42 in response to operating between joint and the separation of chaufeur, 43) the slow-action function part (33) of state, and in response to the operation of chaufeur brake operating part (34) to car body (11) brake activation power

Wherein, driving command part (31) is set to selectively to instruct forward travel state, fallback state and driving command part (31) neither forward travel state any one in the non-driven state of non-fallback state again, wherein, when driving command part (31) is operated with when the non-driven state instruction is forward travel state or fallback state, off-state is switched to coupled condition

Wherein, when carrying out the ON operation of slow-action function part (33), power-transfer clutch (42,43) activated to separate, when carrying out the OFF operation of slow-action function part (33), power-transfer clutch (42,43) activated with joint, and wherein slow-action function part (33) is converted to the OFF operation from the ON operation, off-state is switched to coupled condition

Wherein, when carrying out the ON operation of brake operating part (34), brake activation power, when carrying out the OFF operation of brake operating part (34), brake activation power not, and, wherein brake operating part (34) is converted to the OFF operation from the ON operation, and off-state switches to coupled condition, and

Wherein, and described connection determining section (54, S20), determine whether to carry out the switching of coupled condition based at least one the serviceability in driving command part (31), slow-action function part (33) and the brake operating part (34).

11. according to claim 1 or 3 described drive control apparatus,

It is characterized in that, described Poewr transmission mechanism (18) comprise and have pressure receiving cavity (42a, hydraulic clutch 43a) (42,43), described power-transfer clutch (42,43) according to pressure receiving cavity (42a, 43a) hydraulic pressure in engage and separate between change continuously,

Wherein, described power-transfer clutch (42,43) have the detected pressures of being used for reception cavity (42a, 43a) the hydraulic pressure test section (80,81) of the hydraulic pressure in, and

Wherein, and the connection determining section (54, S20) based on determining by the detected hydraulic pressure in hydraulic pressure test section (80,81) whether the switching of coupled condition is performed.

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