CN101153659A - Running vehicle - Google Patents

Abstract

The invention provides a working vehicle having a hydraulic control apparatus which can increase the pressure smoothly. An elastic return spring supplies the work oil in the forward and backward clutch by stepping the clutch pedal to make the forward and backward clutch in a connection state and makes the forward and backward clutch in a non-connection state by releasing the stepping of the clutch pedal. To the forward and backward clutch in a non-connection state, the device inputs a hydraulic pressure larger than the elasticity of the return spring when starting and outputs a hydraulic pressure from the same as the elasticity of the return spring to a larger one to make the forward and backward clutch in a connection state. Thereof, the forward and backward clutch can increase the pressure from a non-connection state to a connection state.

Description

Moving vehicle

Technical field

The present invention relates to have the working truck of the hydraulic control device of the good hydraulic coupling of maneuverability on the farm.

Background technique

The axletree and the driving force of this axletree that travels is carried out the speed change gear of speed change of travelling about agricultural has with, working truck for building, that transportation is used etc., as the known speed change gear of this speed change gear with following structure, the changement that promptly is provided with the main clutch of the break-make of carrying out engine power and carries out the forward-reverse conversion of vehicle, and the main transformer quick-mounting that is provided with synchromesh below the transmission of changement is put, and also is provided with secondary speed-changing device below its transmission.

In above-mentioned working truck, exist and have the vehicle of structure of hydraulic coupling that main clutch and double as carry out the changement of forward-reverse conversion, in this vehicle, the operation interlock of hydraulic coupling and clutch pedal or forward-reverse bar and carry out work, the inoperative of speed change gear and the control of advancing, retreating.

The hydraulic coupling of following structure is disclosed in Japanese kokai publication hei 7-127668 communique (patent documentation 1), promptly in the hydraulic coupling of the break-make of carrying out speed change gear with the entering into interlock of clutch pedal, if it is big more to be used to connect the amount of entering into of clutch pedal of hydraulic coupling, then reduce the setting current value that on the solenoid-operated proportional control valve that the pistons work of hydraulic coupling is used, flows through more, and, the process of the return of carrying out this clutch from the clutch on positi to the clutch off position, the solenoid-operated proportional control valve is carried out Current Control, make that the return amount of clutch is big more, then the setting current value used from pistons work of current value increases gradually.When having carried out the return of clutch pedal rapidly, in the operational phase at initial stage of this pedal, the hydraulic work state has the tendency of postponement with respect to this pedal operation, thereby the return of pedal is excessively carried out, sometimes produce by the caused speed change of the rapid pressure contact action of clutch friction plate and impact, and above-mentioned this structure has been eliminated this unfavorable condition.

In the structure of above-mentioned patent documentation 1, though the speed change when not having the return of clutch pedal is impacted, but do not consider since the centrifugal force that rotation produced of hydraulic coupling input shaft to clutch hydraulic pressure piston applied thrust, and the situation of the operation sense of touch of this thrust when influencing the operated clutch pedal.

Summary of the invention

Problem of the present invention is to provide a kind of working truck with hydraulic control device, this hydraulic control device is considered being roughly zero state from transmitting torque under the notconnect state of hydraulic coupling and is started working when making boosting that hydraulic coupling connects, the influence of the centrifugal force that produces owing to the rotation of hydraulic coupling input shaft can be boosted smoothly.

Problem of the present invention solves by the following method.

The invention of scheme 1 is a kind of moving vehicle, has: motor 62; From the notconnect state to the coupled condition, the adjustment of the hydraulic pressure by working oil changes the hydraulic coupling D of coupled condition continuously with the power of motor 62; Power transmission mechanism A, the B, the C that carry out work with the power of the state that connected hydraulic coupling D; Adjustment makes hydraulic coupling D be in the clutch operating unit 115,119 of hydraulic pressure of the working oil of coupled condition or notconnect state; Under state, hydraulic coupling D effect elastic force is in backspring 77F, the 77R of notconnect state to hydraulic coupling D effect hydraulic pressure; And, in the occasion that the hydraulic coupling D of notconnect state is applied hydraulic pressure, the initial output stipulated time is than backspring 77F, the hydraulic pressure that the elastic force of 77R is also big, output and backspring 77F afterwards, the hydraulic pressure that the elastic force of 77R is roughly the same, and export gradually than backspring 77F, the hydraulic pressure that the elastic force of 77R is also big and make hydraulic coupling D be in the hydraulic control device 100 of coupled condition, it is characterized in that, has hydraulic control device 100, this hydraulic control device 100 is calculated the centrifugal force in the hydraulic coupling D that the revolution according to motor 62 produces, and according to the centrifugal force in the hydraulic coupling D that calculates, correction makes the hydraulic pressure of hydraulic coupling D work, with the hydraulic pressure of correction make hydraulic coupling D from notconnect state work to coupled condition.

According to the invention of scheme 1,, export the stipulated time hydraulic pressure also bigger at first than the elastic force of backspring 77F, 77R in the occasion of connecting hydraulic coupling D.Output and the roughly the same hydraulic pressure of elastic force of backspring 77F, 77R afterwards, and export gradually than the also big hydraulic pressure of the elastic force of backspring 77F, 77R and make hydraulic coupling D be in coupled condition.

At this moment, in hydraulic coupling D, produce centrifugal force according to the torque of motor 62, so this centrifugal action is in the high side of the contact pressure of hydraulic coupling D.So, revise the hydraulic pressure of the connection usefulness of hydraulic coupling D according to centrifugal force.

The present invention has following effect.

According to the invention of scheme 1, in the occasion of connecting hydraulic coupling D, because the initial output stipulated time hydraulic pressure also bigger than the elastic force of backspring 77F, 77R, so the connection of hydraulic coupling D afterwards becomes good.Have again, adjust hydraulic pressure by basis according to the above-mentioned centrifugal force that engine revolution influences the contact pressure of hydraulic coupling D, thereby obtain good operation sense of touch.

Description of drawings

Fig. 1 is the left view of the tractor of embodiments of the invention.

Fig. 2 is the interior power transmission figure of transmission device of the tractor of Fig. 1.

Fig. 3 is the hydraulic circuit diagram of the power transmission figure of Fig. 2.

Fig. 4 is the structural drawing of the hydraulic coupling used of the forward-reverse power break-make of the speed change gear of Fig. 2.

Fig. 5 is the controlling party block diagram of the hydraulic coupling used of the forward-reverse power break-make of the speed change gear of Fig. 2.

Fig. 6 is the enter into figure of relation of working pressure of the hydraulic coupling that position and above-mentioned forward-reverse power break-make use of the pedal of the tractor of presentation graphs 2.

The figure of the correction value α of the centrifugal force the during work of Fig. 7 hydraulic coupling that to be expression use according to the forward-reverse power break-make of the speed change gear of Fig. 2 and the relation of engine revolution.

Among the figure:

The 1-engine shaft, 2-input shaft, 3-output shaft, the 62-motor, 65-gearbox casing, 76-clutch pack, 77F, 77R-backspring, 78F, 78R-piston, 100-control gear, the 112-engine rotation sensor, 115-forward-reverse cocking lever, 119-clutch pedal, A-main transformer quick-mounting is put, B-high-low speed change device, C-secondary speed-changing device, D-forward-reverse clutch, T-tractor vehicle body.

Embodiment

With the following drawings embodiments of the present invention are described.

Fig. 1 is the left view as the tractor of an example of moving vehicle, Fig. 2 is the interior power transmission figure of transmission device of the tractor of Fig. 1, Fig. 3 is the hydraulic circuit diagram of the power transmission figure of Fig. 2, Fig. 4 is the structural drawing of the hydraulic coupling cylinder used of the forward-reverse power break-make of the speed change gear of Fig. 1, Fig. 5 is the controlling party block diagram of the hydraulic coupling used of the forward-reverse power break-make of the speed change gear of Fig. 4, Fig. 6 is the enter into figure of relation of working pressure of the hydraulic coupling that position and above-mentioned forward-reverse power break-make use of expression pedal, the figure of the correction value α of the centrifugal force when Fig. 7 is the work of representing according to above-mentioned hydraulic coupling and the relation of engine revolution.

Fig. 1 represents the side view of the tractor of present embodiment.

Tractor vehicle body T with the mode of travelling of riding four-wheel drive, the running of when handling front-wheel 61, travelling with steering tiller 73.Rotary tillage device 84 working machines such as grade can liftably be installed at the rear portion of vehicle body T carry out operation over the ground.This vehicle body T carries motor 62 at front end by the engine bracker that is erected on the front axle housing, rear side at this motor 62 connects clutch housing and gearbox casing 65 etc. integratedly, rear portion at this gearbox casing 65 is provided with rear axle housing 75, at left and right sides portion axle dress trailing wheel 63.

Fig. 2 represents the power transmission system figure of the tractor of present embodiment.

Motor 62 has outstanding engine shaft 1 at rear side, this engine shaft 1 is connected on the input shaft 2 of clutch housing portion.Make output shaft 3 and PTO axle 14 by the driving mechanism interlock rearward end in the gearbox casing 65, interlock is located at the structure of front wheel output shaft 5 of the bottom of gearbox casing 65 simultaneously.The substantial middle portion at this rear portion of output shaft 3 in gearbox casing 65 is supported by axle along fore-and-aft direction, and has a driver pinion 53 in the rear end, with differential gear 46 engagements of back differential mechanism 45, by back differential axle 10 and the rear-wheel spindle 11 of planetary gear speed reducing mechanism interlock along back axle columella dress.And, front wheel output shaft 5 is from the bottom of the bottom process motor 62 of gearbox casing 65, be connected with the input shaft 26 of the preceding differential mechanism 47 of the central part that is located at front axle housing, and by along the preceding differential axle 12 of this propons columella dress and planetary gear speed reducing mechanism etc. to front wheel spindle 13 interlocks.In addition, be configured in side by side on the input shaft 2 from the gear drive axle 15,17 of input shaft 2 to the power taking-up usefulness of oil hydraulic pump 80 (Fig. 3).

The transmission device of present embodiment is provided with PTO clutch pack 66 on the PTO jack shaft 9 with PTO speed change counter gear 44, the input shaft 2 and input gear 31 interlocks of PTO speed change counter gear 44 from being driven by engine shaft 1.And, on input shaft 2, be provided with the forward-reverse conversion gear 42,42 of forward-reverse conversion usefulness with revolution state, be located at input shaft 2 in engagement on a side the forward-reverse conversion gear 42 that retreats side and place side by side back counter gear 43 on the rear intermediate shaft 8 of configuration, on the forward-reverse conversion gear 42 of the opposing party's advance side, the input gear 48 that is fixed on the main variable-speed shaft 19 is set and revolves round the sun and be located at four different mains 33 of pitch diameter on this main variable-speed shaft 19 freely.These four mains 33 constitute the level Four speed change, utilize clutch pack 76 to change speed change, will be called the main transformer quick-mounting by the speed change gear that four mains 33 constitute and put A.

On above-mentioned main variable-speed shaft 19, between main 33 (first speed with) that above-mentioned main transformer quick-mounting is put pitch diameter minimum in four mains 33 of A and the 3rd little main 33 of pitch diameter (third speed with), fixedly install clutch pack 76, between the main 33 of second little main 33 of pitch diameter (second speed usefulness) and pitch diameter maximum (the 4th speed with), fixedly install clutch pack 76.On above-mentioned two clutch packs 76, be respectively equipped with the friction clutch that each main 33 and main variable-speed shaft 19 one are connected rotatably.

In addition, can with the input gear 48 of the gear engagement of the advance side of forward-reverse conversion gear 42, with back counter gear 43 engagements on the gear that retreats side of forward-reverse conversion gear 42 and the rear intermediate shaft 8, ground and input shaft 2 being integral are selected in the conversion of two forward-reverse conversion clutch assemblies 60 that the gear 42 of the advance side in this forward-reverse conversion gear 42 and the gear 42 that retreats side independently are made of friction clutch by front and back, and converting to advances travels and retreat and travel.Comprise that cylinder 85 described later (Fig. 3) will be called forward-reverse clutch D by the structure that these gears 42 and clutch pack 60 etc. constitute.

In addition, will be located on the leg portion of steering tiller 73 with the forward-reverse cocking lever 115 of the conversion of manually carrying out forward-reverse clutch D, clutch pedal 119 is located at the underfooting of handle pillar 73, and clutch pedal 121 is located near the handle.

With the secondary variable-speed shaft 20 of main variable-speed shaft 19 concentric settings on be provided with two the different high low speed conversion gears 34 of pitch diameter that utilize clutch pack 76 conversion speed changes, can slow down to the driving force after the main transformer speed again and be converted at a high speed and low speed.This gear structure that is convertible into high speed and low speed is called high-low speed change device B.

Have again, with dispose output shaft 3 on secondary variable-speed shaft 20 is coaxial with three different secondary speed change gears 35 of pitch diameter.Output shaft 3 is made the structure of carrying out three-step gear shift by secondary speed change gear 35.This structure that can carry out the gear 35 of three-step gear shift is called secondary speed-changing device C.

In addition, have with the creep jack shaft 21 of the creep counter gear 49 of secondary speed change gear 35 engagements with and column position be located on the output shaft 3.And, have travel jack shaft 6 and main variable-speed shaft 19 and secondary variable-speed shaft 20 with the main transformer of engagements such as main 33 and high low speed conversion gear 34 speed counter gear 39 and high low speed conversion gear 40 with position configuration arranged side by side, by main 33 speed changes, this rotation is successively via main transformer speed counter gear 39 and high low speed conversion gear 40 and be delivered on the high low speed conversion gear 34 that is located on the secondary variable-speed shaft 20 from the rotation of main variable-speed shaft 19 transmissions.The power that is delivered to high low speed conversion gear 34 is by clutch pack 76 and by being delivered on the output shaft 3 according to the gear that is located at the secondary speed change gear 35 on the secondary variable-speed shaft 20.

In the driving dynamics delivery system of present embodiment, be provided with the clockwise and anticlockwise PTO of the kind of drive of the conduct rotation PTO couple axle 4 that possesses PTO clockwise and anticlockwise gear changing 37 mechanisms.

In addition, be provided with front-wheel couple axle 28, the secondary speed change jack shaft 27 of the secondary speed change counter gear 38 that meshes with above-mentioned secondary speed change gear 35 is supported in these front-wheel couple axle 28 rotations freely, and have from the front-wheel linked gear 51 of output shaft 3, on prolongation axle center, the place ahead of this front-wheel couple axle 28, be provided with PTO deboost axle 23 with PTO reduction gear 50 by front-wheel taking-up gear 36 interlocks.Have again, on the parallel position of front-wheel couple axle 28, be provided with PTO couple axle 4, with these PTO couple axle 4 concentrics on front end dispose PTO couple axle 4 be converted to the positive and negative transaxle 22 of PTO of PTO clockwise and anticlockwise gear changing 37 of main story and counter-rotating and the PTO variable-speed shaft 18 of PTO speed change gear 32.

In addition, constitute and have the sidepiece that is located at the positive and negative transaxle 22 of above-mentioned PTO with the PTO counter-rotating jack shaft 24 of the PTO counter gear 52 of PTO clockwise and anticlockwise gear changing 37 engagement, by the connection of PTO clutch pack 66, pass through PTO speed change gear 32, PTO speed change counter gear 44 and PTO clockwise and anticlockwise gear changing 37 etc. to positive and negative transaxle 22 transfer motion powers of PTO from input shaft 2.Above-mentioned clockwise and anticlockwise gear changing 37 is made the mode of the clutch ring of use and above-mentioned PTO speed change gear 32 same way as.Be provided with the counter-rotating jack shaft 24 with PTO counter gear 52 in the side of the positive and negative transaxle 22 of this PTO, PTO counter gear 52 can be accepted interlock and reverse PTO clockwise and anticlockwise gear changing 37 from PTO reduction gear 50.In addition, dispose deboost axle 23 at the rear of above-mentioned PTO jack shaft 9.

Have, 5 of front wheel output shafts that are configured in the lower layer part in the gearbox casing 65 are contained on the bottom, rear portion of gearbox casing 65, are connected to the input shaft 26 of above-mentioned preceding differential mechanism 47 by front-wheel couple axle 25 and coupling etc. again.Cross side at this front wheel output shaft 5 disposes front wheel driving shaft 7.Wheel gear 55 before the rear end of front wheel driving shaft 7 is provided with.And, the first front-wheel linked gear 51 on engagement front-wheel couple axle 28 on the front-wheel output gear 36 of the rearward end of above-mentioned output shaft 3, the driving force that is delivered to the output shaft 3 of front-wheel couple axle 28 by this first front-wheel linked gear 51 is delivered to the second front-wheel linked gear 54 that rotates with front-wheel couple axle 28 one, and is delivered to front wheel driving shaft 7 from this front-wheel linked gear 54.

In addition, front-wheel drive clutch pack 67 is located on the front wheel driving shaft 7, carries out the gear interlock to front wheel output shaft 5 from the front end of this live axle 7.And, two front-wheel drive conversion gears 41 that pitch diameter is different be configured in front-wheel drive clutch pack 67 about, these two front-wheel drive conversion gears 41 are engaged on respectively on two different conversion driving counter gears 56 of the pitch diameter that is located on the jack shaft 59, connect by front-wheel drive clutch pack 67 is selected a ground, can recently drive front wheel driving shaft 7 with any deceleration in two reduction speed ratio.

Be made as when front-wheel drive clutch pack 67 is displaced to the neutral position and do not make two of rear wheel drive that front-wheel 61 drives drive mode, by hydraulic operation this front-wheel drive clutch pack 67 is changed and to be made as the 4 wheel driven mode that front-wheel 61 relative trailing wheels 63 are driven with about 1 times of constant speed when being displaced to low-speed position, and, by hydraulic operation this front-wheel drive clutch pack 67 is changed to be made as the 4 wheel driven mode that front-wheel 61 relative trailing wheels 63 are driven with about 2 multiplication speed when being displaced to high speed position, thereby can be travelled.

By the meshing type speed variator that constitutes by said structure, the rotating power of motor 62 via the forward-reverse clutch D that constitutes main clutch utilize that the main transformer quick-mounting that is made of 4 grades of speed change levels is put A, the high-low speed change device B that constitutes by 2 grades of speed change levels and become to add up to 24 grades by the secondary speed-changing device C speed change that 3 grades of speed change levels constitute in any speed change level, the rotating power that obtains drives trailing wheels 63 through differential mechanism 45 later.And, the rotating power that carries out speed change with above-mentioned secondary speed-changing device C also is delivered on the front-wheel drive clutch pack (two drive the 4 wheel driven conversion clutch) 67, make front-wheel 61 be converted to " constant speed " or " speedup " afterwards by this clutch pack 67, warp differential mechanism 47 later drives front-wheels 61.

In addition, the main 33 of PTO speed change gear 32, driving system, high low speed conversion gear 34 and secondary speed change gear 35 etc. are disposed on the axle center of the output shaft 3 with driver pinion 53.The transmission of driving system is carried out multi-change speed interlock by the main on the axle center that is configured in output shaft 3 33, high low speed conversion gear 34 and secondary speed change gear 35 etc. to driver pinion 53 from input shaft 2.And the speed change of PTO system is carried out interlock by the PTO speed change gear 33 of the front end on the axle center that is located at this output shaft 3.

Then, Fig. 3 represents the hydraulic circuit diagram of the tractor of present embodiment.

In the hydraulic circuit diagram of Fig. 3, be provided with trailing wheel 63 about independent brake about master cylinder 83, will be delivered to the power-converting of front-wheel 61 carries out work for the 4 wheel driven conversion clutch cylinder 99 of " constant speed " or " speedup ", by the rotary manipulation of steering tiller 73 power steering gear 103, PTO clutch cylinder 104, PTO clutch pressure control with valve 105,106 etc.In addition, the loop 101 of single-point line part is called main oil hydraulic circuit (working machine lifting, working machine level and external hydraulic taking-up etc.), has little or nothing to do with sub-loop (travel, braking, differential lock, PTO side loop), has therefore omitted the diagram of circuit diagram.

The working oil of discharging from oil hydraulic pump 80 by reduction valve 81a supply to conversion by clutch pack 76 make respectively the 4th speed that the main transformer quick-mounting puts A with and the speed change control valve 89 used with the 4-2 rate conversion of the hydraulic coupling cylinder 87 of each gear 33 work and hydraulic coupling cylinder 88 of second speed, be re-supplied to the speed change control valve 93 that the 1-3 rate conversion of hydraulic coupling cylinder 91 that each gear 33 that first speed is used and third speed is used that conversion makes the main transformer quick-mounting put A respectively works and hydraulic coupling cylinder 92 is used.

Supply to the advance side and the changing valve 86 that retreats the clutch D of side of conversion forward-reverse clutch cylinder 85 by the on-off control valve 129 of forward-reverse clutch cylinder 85 via the working oil of reduction valve 81a.In the advance side of this forward-reverse clutch cylinder 85 with retreat and supplied with working oil among the clutch D of side which and just can and retreat side clutch pressure sensor 111 and detect with advance side clutch pressure sensor 110.

Equally, the working oil of addressing following hydraulic coupling cylinder in the supply can detect with being located at each pressure transducer on the oil circuit of the inlet side of hydraulic coupling cylinder.

In addition, the master cylinder 83 about the working oil of discharging from oil hydraulic pump 80 is supplied with via brake valve 82a branch by reduction valve 81b.Above-mentioned brake valve 82a is a switchover control valve of selecting trailing wheel 63, and this brake valve 82a constitutes with the pressure controlled valve 82b one of adjusting braking force.

Have again, supply with control valve 96a, 96b via the working oil of reduction valve 81b, this control valve 96a, 96b are used to change the speed that will carry out speed change with each gear 33 that above-mentioned first speed～the 4th speed is used and carry out the height hydraulic coupling cylinder 95 of work by clutch pack 76 to any of two gears 40 of " at a high speed " and " low speed ".

In addition, the working oil via reduction valve 81b branches into the front-wheel differential lock cylinder 98a of preceding differential mechanism 47 usefulness and the trailing wheel differential lock cylinder 98b of back differential mechanism 45 usefulness through differential lock control valve 97.

The working oil of supplying with via above-mentioned reduction valve 81b through switchover control valve 94 on the oil hydraulic cylinder 99 of the conversion usefulness of the gear 41 of front-wheel drive clutch pack 67 is arranged again.

Equally, supply with PTO clutch cylinder 104 by PTO with valve 105,106, adjust the pressure of PTO clutch via the working oil of reduction valve 81b.

In addition, the hydraulic pressure from oil hydraulic pump 80 shown in Figure 3 is the structure of the hydraulic steering gear 107 that carries out work with the operation of servosteering handle 73 being supplied with working oil.

Fig. 4 represents to carry out the cross-section structure of forward-reverse clutch cylinder 85 of the conversion of forward-reverse gear 42,42.

In a pair of cylinder 85F in the front and back of cylinder 85,85R, be respectively equipped with the forward- reverse conversion clutch 60,60 that piston 78F, 78R that works respectively by the working oil (oil) that flows into and the many groups friction plate that is contacted with each other by the work with this piston 78F, 78R constitute.

Oil flows in any cylinder 85F, 85R of the usefulness that moves forward and backward (not carry out entering into when operating of foot-operated pedal 119) when inoperation clutch pedal 119, thereby piston 78F or 78R become working state, forward-reverse conversion clutch assembly 60,60 becomes coupled condition, and engine power is delivered to the driving mechanism of the advance side in the speed change gear 24 or retreats the driving mechanism of side.In addition, in each cylinder 85F, 85R, be provided with backspring (pressure spring) 77F, 77R, this backspring 77F, 77R respectively to releasing advance, a side effect of the coupled condition of back clutch assembly 60,60.Thereby, if operated clutch pedal 119 (carrying out the operation of entering into of foot-operated pedal 119), then the oil in cylinder 85F or the 85R flows out, because the elastic force of backspring 77F or 77R and piston 78F or 78R move to Return-ing direction, this advances or the coupled condition that retreats the clutch pack 60 of usefulness is disengaged.

In the forward-reverse conversion clutch assembly 60 of said structure, because the centrifugal force that produces because of the rotation as the input shaft 2 of Clutch input shaft, the oil in piston 78F or the 78R is to piston 78F or 78R applied thrust.Thus, produce the transmission of power torque in the torque of the input shaft 2 that produces by the hydraulic pressure compaction pressure, to add the power of the thrust that causes by centrifugal force.

Above-mentioned centrifugal force can be obtained with following formula.

At first, oil in clutch cylinder 85F or 85R and advance side clutch pack 60 or retreat the occasion that side clutch pack 60 becomes one fully and is rotated, the pressure P radially of input shaft 2 is represented (formula of forced vortex) with following formula.And, the distribution radially of the input shaft 2 of pressure P as shown in Figure 6, the value of radial outside pressure P is big more.

P＝P ₀+1/2ρr ²ω ² (1)

Here, P ₀: axial pressure (Pa), ρ: density (kg/m ³), r: from the distance (m) in axle center, ω: clutch angular velocity (rad/s).

Thereby the thrust of piston 78F or 78R obtains following formula (2), (3) by formula (1) radially being carried out the area branch.

${F=\&Integral;\mathrm{PdA}=P}_{0}A+{\&Integral;}_{\frac{{\mathrm{\&Phi;}}_1}{2}}^{\frac{{\mathrm{\&Phi;}}_2}{2}}\frac{1}{2}{\mathrm{\&rho;<figure-callout\; id="2"\; label="r"\; filenames="A20071016164400171.png,A20071016164400211.png"\; state="\{\{state\}\}">r</figure-callout>}}^2{\mathrm{\&omega;}}^2\&times;2\mathrm{\&pi;rdr}---\left(2\right)$

$F=P_{0}A+\frac{1}{64}{\mathrm{\&rho;\&pi;\&omega;}}^2({{\mathrm{\&Phi;}}_2}^4-{{\mathrm{\&Phi;}}_1}^4)---\left(3\right)$

Here, F: piston thrust (N), A: piston area (m ²), Φ 1: piston inner diameter (m), Φ 2: piston external diameter (m).

First expression of formula (3) be with the caused piston 78F of pilot pressure of the not shown hydrovalve of electromagnetic coil 86F or 86R work or the thrust of 78R, the caused thrust of centrifugal force of the oil in second expression cylinder 85F or the 85R.

According to formula (3), even the pressure that above-mentioned hydrovalve causes is zero, as long as advance side clutch pack 60 or retreat clutch pack 60 rotations of side, thrust just produces, and therefore, the location load of backspring 77F or 77R must be bigger than the thrust that centrifugal force causes.And, though this thrust can not be used determination of pressure sensor, can decide by the revolution of input shaft 2, therefore can be according to engine revolution (detecting) supposition with engine rotation sensor shown in Figure 5 112, and carry out correspondingly control.

So, carry out the clutch pack 60 of the forward-reverse hydraulic coupling D of break-make in the present embodiment for operation interlock with clutch pedal 119 grades, can carry out half-clutch device operation according to the pressure of the operating position of clutch pedal 119 change forward-reverse hydraulic coupling D, and according to engine revolution (or revolution of input shaft 2) revise according to the position of clutch pedal 119 at advance side clutch pack 60 or retreat applied pressure on the side clutch pack 60.

Fig. 6 represents that the position of clutch pedal 119 is connected the relation of pressure with clutch, position as clutch pedal 119, the clutch engagement pressure of (advance side clutch pack 60 or retreat side clutch pack 60 be complete notconnect state, the position P1 of pedal 119) is specified value (1kgf/cm when fully having entered into pedal 119 ²), but from advance side clutch pack 60 or retreat side clutch pack 60 complete notconnect states and become advance side clutch pack 60 or retreat side clutch pack 60 complete contact conditions (the position P2 of pedal 119), specified value (10kgf/cm for example need become up to clutch engagement pressure by returning pedal 119 ²) during, will add that the hydraulic pressure according to the correction pressure alpha of above-mentioned centrifugal force is applied to advance side clutch pack 60 or retreats side clutch pack 60.

Fig. 7 represents the relation of engine revolution and above-mentioned correction pressure alpha, revising pressure alpha under idling conditions is maximum value, reduce successively during engine revolution arrives rating value (for example 2200rpm), revising pressure alpha when engine revolution is rating value (for example 2200rpm) is zero.The thrust of the low more piston 78F of engine revolution, 78R is more little, and centrifugal force is also more little, so need to increase the correction pressure alpha.

In addition, owing to obtain piston thrust according to the sectional area of clutch plunger 78F, 78R and the product of engine revolution, therefore, as long as determined the piston 78F of hydraulic coupling D, the structure of 78R, just can be in advance be kept at value on the storage of controller 100 as data with the piston thrust of obtaining by computing according to the above-mentioned correction pressure alpha correction of engine revolution, when carrying out the pressure control of clutch pedal 119, read the preservation data according to engine revolution and make advance side clutch pack 60 or retreat 60 work of side clutch pack.

In addition, also can replace engine revolution and calculate the thrust (torque) of above-mentioned correction pressure alpha or input shaft 2 based on the revolution of input shaft 2.At this moment can be with calculating the thrust (torque) of revising pressure alpha or input shaft 2 by engine revolution with to the revolution of the input shaft 2 of the deceleration computing recently of the input shaft 2 that becomes object.

Like this, utilize the centrifugal force shown in the above-mentioned formula (3) that rotation produced of the rotation of motor or input shaft 2, oil in clutch cylinder 85F, the 85R is to piston 78F, 78R applied thrust, thus, at advance side clutch pack 60 or retreat side clutch pack 60 and produce the transmission of power torques, therefore just can not provide predetermined clutch to connect torque with the power that in the torque of the input shaft 2 that produces by the hydraulic pressure compaction pressure, adds thrust with the torque of engine revolution or input shaft 2 and to the supply pressure of piston 78F, 78R by above-mentioned centrifugal force.So,, then can obtain good operation sense of touch if carry out clutch operating in the torque of the input shaft 2 that produces by the hydraulic pressure compaction pressure according to the revolution of engine revolution or input shaft 2, to add according to the power of the thrust of above-mentioned centrifugal force.

In addition, owing on piston 78F, the 78R of forward-reverse clutch D, apply the centrifugal force shown in the above-mentioned formula (3), therefore will be created in the backspring 77F, the 77R that append the thrust of above-mentioned centrifugal force on the piston thrust that maximum revolution was produced with the Clutch input shaft 2 of the engine revolution reduction speed ratio of 2 revolution (or from the engine revolution to the Clutch input shaft) computing and be configured on the piston Return-ing direction.

As forward-reverse hydraulic coupling (changement) D of present embodiment, the structure of clutch that the clutch 60,60 used of a pair of forward-reverse of configuration etc. has a reduction speed ratio of two systems in a cylinder body is widely used.In this occasion, if the above-mentioned centrifugal force that is produced by the revolution of forward-reverse clutch D is also bigger than the elastic force of backspring 77F, 77R, then forward-reverse clutch D becomes dual engagement, the danger that exists the clutch pack 60 of non-outlet side to wear and tear gradually.

For this reason, as mentioned above, provide the big elastic force that has appended above-mentioned centrifugal force, can carry out the disconnection of coupled condition of each clutch pack 60,60 of forward-reverse clutch D smoothly by piston return force with backspring 77F, 77R.

In addition, if the piston return force with backspring 77F, 77R provides the big elastic force that has appended above-mentioned centrifugal force on the contrary, then make clutch pack 60,60 when notconnect state is in coupled condition, going up streaming current and carrying out travel time than piston 78F, 78R that the initial stage of short time exports a little at the electromagnetic coil 86F that produces the thrust enough bigger or 86R than the elastic force (thrust) of backspring 77F, 77R.Thus, the thrust also bigger than the elastic force of backspring 77F, 77R that can be used under the notconnect state of forward-reverse clutch D begins the work of piston 78F, 78R, supplies with afterwards from clutch returning pressure (reaction force) compaction pressure to clutch pack 60,60 about equally with the elastic force computing of available backspring 77F, 77R to overcome the pressure of above-mentioned reaction force gradually and make forward-reverse clutch D be in coupled condition.

Like this, can be implemented under the notconnect state of forward-reverse clutch D and to be roughly zero state from transmitting torque and to make piston 78F, 78R work up to connecting boosting of forward-reverse clutch D.

In addition, the boost pressure of using from the pistons work of the notconnect state of above-mentioned hydraulic coupling D is revised pressure according to the input revolution (the input shaft revolution of available engine revolution and reduction speed ratio computing gets final product) of Clutch input shaft 2.It is the reasons are as follows.

Promptly, as mentioned above, because the transmission of power torque that produces piston 78F, 78R with the power of in the torque of the Clutch input shaft 2 that produces with the hydraulic pressure compaction pressure, appending according to the thrust of centrifugal force, therefore just can not provide predetermined clutch connection torque with input revolution, the supply hydraulic pressure of Clutch input shaft 2.By revise the thrust of the connection usefulness of forward-reverse clutch D according to the revolution of engine revolution or Clutch input shaft 2, can revise the difference when operation forward-reverse clutch D like this because of the different operation senses of touch that produce of engine revolution.

Have again, when the connection of beginning forward-reverse clutch D, elastic force for backspring 77F, 77R, make the roughly the same degree of the elastic force of thrust that the maximum revolution degree of the revolution of the Clutch input shaft 2 when having appended centrifugal force produces and the value of appending of supplying with hydraulic coupling and backspring 77F, 77R and begin to boost, make the difference in change of pressure become slow and convert the structure that improves hydraulic pressure gradually to, also can realize changing smoothly.The above-mentioned degree that improves hydraulic pressure gradually is made as 1kgf/cm ²The degree of variation to change in about 0.5～1 second.

Like this, when beginning to connect forward-reverse clutch D, if begin to boost from supply pressure with the roughly the same degree of the elastic force of backspring 77F, 77R, then can be successfully, the variation in pressure when promptly clutch pack 60 engages makes forward-reverse clutch D be in on-state lessly.

In addition, decide in the structure that the hydraulic control pressure of forward-reverse clutch D controls, can constitute also that engine revolution is high more to be modified to above-mentioned hydraulic control pressure lower at operating position according to clutch pedal 119.This is because because the influence of above-mentioned centrifugal force, the transmitting torque of the high more piston 78F of engine revolution, 78R is big more, is difficult to make forward-reverse clutch D to disconnecting the direction action.And the occasion engine output torque high in engine revolution is also big, and the speed change when the low caused clutch of engine torque aligns is impacted the reduction effect and also weakened.Therefore, by making said structure, the transmitting torque that can suppress when motor is high to be rotated is too high.

In addition, also can make following structure, promptly when operated clutch pedal 119, do not carry out correction according to above-mentioned centrifugal force, operation is used to carry out the advancing of not shown vehicle, the neutral or forward-reverse cocking lever 115 that retreats, according to the connection of the forward-reverse clutch D of predefined relatively forward-reverse bar operation amount or the curve (not shown) of disconnected usefulness, carry out the correction of the revolution (revolution of the input shaft 21 of available engine revolution and reduction speed ratio computing gets final product) of the Clutch input shaft 2 when hydraulic pressure is boosted.

The operation of clutch pedal 8 according to the people feel carry out, therefore operate the sensation that vehicle begins to move with pin.If in the operation of carrying out with this pin, add correction according to above-mentioned centrifugal force, then need to append when beginning to travel according to the change of the engine revolution of load variations and quicken operation and the whole of clutch operating revise, also need not reply fully the controller of hysteresis, and, need control system at high price in order to reach these purposes.

To this, use the hydraulic coupling control that above-mentioned forward-reverse bar 115 carries out, the content of people's operation is entrusted to the people, only correction according to above-mentioned centrifugal force is carried out in the control of using forward-reverse bar 115, thereby cheapness and the good system of sense of touch can be provided.

At this moment make the structure of the correction pressure of the high more hydraulic control that reduces the forward-reverse clutch D that causes by above-mentioned centrifugal force more of engine revolution.

In addition, the correction of above-mentioned hydraulic control pressure is only carried out when low-pressure, does not revise after pressure uprises.Its reason is, when carrying out delicate torque control if the torque difference that Clutch input shaft 2 is applied then the impact during speed change become big, still, pressure uprises after, just do not need.So in the case of necessary, do not need to revise computing of hydraulic control pressure etc. by carrying out above-mentioned correction.

In addition, also can make on the contrary and carry out above-mentioned correction in all-hydraulic control area.This occasion because that the thrust that causes of centrifugal force is done is auxiliary, also can suppress to control electric current even therefore revise in all-hydraulic zone, can save energy.And engine revolution is high more can be suppressed the hydraulic pressure (electric current) of control usefulness low more, has the effect of saving energy.

Utilizability on the industry

The comparable control of travelling of in the past carrying out accurately the working trucks such as tractor of the present invention, thus can obtain The vehicle that operability is good.

Claims (1)

1. moving vehicle has:

Motor (62);

From the notconnect state to the coupled condition, the adjustment of the hydraulic pressure by working oil changes the hydraulic coupling (D) of coupled condition continuously with the power of motor (62);

The power transmission mechanism (A, B, C) that carries out work with the power of the state that connected hydraulic coupling (D);

Adjustment makes hydraulic coupling (D) be in the clutch operating unit (115,119) of hydraulic pressure of the working oil of coupled condition or notconnect state;

Hydraulic coupling (D) is not being acted under the state of hydraulic pressure, hydraulic coupling (D) effect elastic force is being in the backspring (77F, 77R) of notconnect state; And,

In the occasion that the hydraulic coupling (D) of notconnect state is applied hydraulic pressure, the initial output stipulated time is than the also big hydraulic pressure of elastic force of backspring (77F, 77R), export the corresponding hydraulic pressure of elastic force afterwards with backspring (77F, 77R), and export gradually than the also big hydraulic pressure of elastic force of backspring (77F, 77R) and make hydraulic coupling (D) be in the hydraulic control device (100) of coupled condition, it is characterized in that

Has hydraulic control device (100), this hydraulic control device (100) is calculated the centrifugal force in the hydraulic coupling (D) that the revolution according to motor (62) produces, and according to the centrifugal force in the hydraulic coupling of calculating (D), correction makes the hydraulic pressure of hydraulic coupling (D) work, with the hydraulic pressure of correction make hydraulic coupling (D) from notconnect state work to coupled condition.

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