JPS602205B2 - Transmission devices for tractors, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides two sets of transmissions arranged in series in the power transmission path from the engine to the final drive means such as wheels. A plurality of sets of variable speed gear units are arranged on the drive shaft located at A self-propelled working vehicle such as a tractor, combine harvester, or riding rice transplanter (hereinafter referred to as , "tractor, etc."

) is related to the 0 transmission device. A transmission for a tractor or the like equipped with a hydraulic clutch type transmission as described above is known, for example, from U.S. Pat. No. 3,831,69 issued to the applicant of the present application, The running power transmission mechanism such as
Hyde.

Compared to those using static transmissions, this type of transmission has advantages such as a simpler structure and lower cost, but the purpose of this invention is to 0 Hydraulic clutch type transmission The hydraulic clutch type of the previous stage is changed depending on the gear position of the rear gearbox, that is, the gear position or reduction gear of the rear gearbox, which changes the equivalent inertial mass according to its reduction ratio. In order to be able to control the start-up mode of the transmission and achieve smooth operation of the transmission,
The present invention is intended to construct a transmission as described above. To explain the configuration of the transmission device for a tractor or the like according to the present invention with reference to the illustrated embodiment, first, as shown in FIG. The intermediate shaft 3 parallel to the drive shaft 2 can be connected in motion via a hydraulic clutch type main transmission 4 disposed between the two shafts 2 and 3, and an extension of the drive shaft 2. A gear-shifting sub-type consisting of a reduction gear wheel, which is rotated by an intermediate shaft 3, and a shift gear wheel on another intermediate shaft 5, which is provided on an extension of the intermediate shaft 3. A transmission 6 is provided downstream of the main transmission 4, and the intermediate koji 5 is connected to the differential 7.
It is configured to be interlocked and connected to the axle 8a of the traveling drive wheel 8 via the following.

That is, first, the configuration of the main transmission 4 will be explained with reference to FIG. 1. The main transmission 4 consists of an FI gear 9 iron-bonded to the drive shaft 2 and an FI gear 9 meshed with the intermediate shaft 3. An FI transmission gear unit consisting of a combination of an FI gear 10, an F2 gear 11 iron-bonded to the drive shaft 2, and an F gear 11 which is loosely connected to the intermediate shaft 3 and meshed with the F2 gear 11.
A combination of an F2 variable speed gear unit consisting of a combination of two gears 12, an F$ gear 13 iron-bonded to the drive wheel 2, and an F3 gear 14 which is loosely attached to the intermediate shaft 3 and meshed with the F bead gear 13. an R gear 15 which is iron-bonded to the drive shaft 2, and an R intermediate gear 16 which is freely rotatably supported and meshed with the R gear 15; It is configured to include four sets of speed change gear units including an R speed change gear unit consisting of a combination of an R gear 17 meshed with a gear 16, and an FI hydraulic clutch in the above FI speed change gear units 9 and 10. 18,
An F2 free pressure clutch 19 is installed in the F receiving/receiving speed gear units 11 and 12, an F3 free pressure clutch 20 is installed in the F3 speed change gear units 13 and 14, and an R speed change gear unit 15, 16, 17.
R hydraulic clutches 21 are respectively disposed in the R hydraulic clutches 21,
One friction plate is supported by the clutch housing on the intermediate shaft 3, and the other friction plate is supported by each of the above-mentioned idler gears 10, 12, 14, 17, so that they can only swing freely in the direction of the clutch axis, thereby creating a multi-plate type hydraulic system. By selectively ironing any one of these hydraulic clutches 18 to 21 that constitute a clutch, the drive shaft 2 and the intermediate shaft can be connected to each other via the transmission gear unit to which the hydraulic clutch belongs. The structure is such that the three can be interlocked and connected. Next, referring again to FIG. 1, the configuration of the dramatic transmission device 6 will be explained. This sub-transmission device 6 includes a dog clutch 22 arranged between the intermediate shafts 3 and 5, A gear 23 is integrally formed with the pulp 3 at the end and has one engagement piece 22a of the dog clutch 22, and a shift gear 24 is spline-coupled with the intermediate shaft 50. A shift gear 24 is formed with the other meshing piece 22b of the dog clutch 22, and two integral shift gears 25, 26 are splinted to the intermediate shaft 5 with a common boss portion thereof.
and four gears 27, 28, 29, 30 integrally connected to the drive shaft 2 with a common boss portion, and by meshing the gear 27 at the base end with the gear 23, the intermediate shaft 3
Four gears 27 and 30 are configured to rotate integrally with the drive shaft 2 and the intermediate shaft 5, and two gears are loosely connected to the shaft 31 provided in parallel with the drive shaft 2 and the intermediate shaft 5 as common to the boss portion thereof. The two gears 32, 33, which are made to rotate integrally with the intermediate shaft 3 by aligning the base end side gear 32 with the gears 3, and the drive shaft 2. Two gears 34 and 35 are rotated with the boss portion in common, and by meshing the gear 34 on the larger diameter side with the gear 33, it rotates integrally with the intermediate shaft 3 like the gears 32 and 33. The shift fork (the fourth
The shift gears 24, 25, 25 and 25 are operated by the change lever 70 shown in FIG. 26 on the intermediate shaft 5, and when the shift gear 26 is engaged with the gear 35, the first speed (very low speed) is set.
When the shift gear 25 is meshed with the gear 30, the 2nd speed is set. When the shift gear 25 is meshed with the gear 29, the 3rd gear is set.
The gear ratio is determined so that when the gears 8 and 8 are engaged, 4 distances are obtained, and the shift gear 24 is displaced and the engagement pieces 22a and 22b are engaged to form the engagement clutch 22.
When operating the intermediate shafts 2 and 5, the intermediate shafts 2 and 5 are directly connected to obtain 5th speed.

That is, the traveling drive of the tractor shown in the drawing is performed by the main transmission 4, which operates the FI transmission gear units 9 and 10 by the input of the FI hydraulic clutch 18, and the first forward speed by which the F2 hydraulic clutch 19 is loaded. Multi-speed gear unit 1
1 and 12 are activated, forward 3rd speed is activated by the F3 hydraulic clutch 20 being engaged to activate the F3 gear units 13 and 14, and R hydraulic clutch 21 is being engaged to achieve the R gear unit 15. , 16 and 17 are actuated, and it is possible to switch to four speeds, including reverse IZ far, and furthermore, the above-mentioned sub-transmission device 6 allows shifting to five speeds among the above-mentioned speeds. As described above, two sets of transmissions 4 and 6, the main Z transmission 4 and the auxiliary transmission 6, are arranged in series in the power transmission path from the engine 1 to the travel drive wheels 8, which are the final drive means. However, the main transmission 4 is configured to provide a four-speed shift, and the sub-transmission 6 is configured to provide a five-speed shift. The mechanism for selectively operating the two is constructed as follows.

That is, to explain this with reference to FIGS. 2 and 3, the clutch hydraulic oil supply and discharge mechanism for this purpose is configured to supply and discharge hydraulic oil from the oil tank 38 to the hydraulic clutches 218 and 21, as shown in FIG. The oil supply circuit 4, in which the hydraulic pump 39 is inserted, runs from the oil tank 38 to the hydraulic clutch 18-21, and is connected to the illustrated cutoff valve 41, that is, the illustrated neutral position N, and the FI hydraulic clutch 18. A switching valve that can be switched to four positions: FI position 3 for refueling, F2 position for refueling the F28 pressure clutch 19, F3 position for refueling the F3 bending pressure clutch 20, and R position for refueling the R hydraulic clutch 21. 41 is inserted, and as usual, the oil pressure of the oil supply circuit 40, and therefore the working oil pressure of the hydraulic clutches 18-21, is set in the branch circuit 42 connected to the four oil supply circuits at the stage before this switching valve 41. Pressure regulating valve 4 for
3 was inserted, and the refueling circuit 4 was also installed with the switching valve 4 on the aircraft.
1, a lubricating oil supply circuit 45 into which a throttle 44 can be inserted is connected. The pressure regulating valve 43, which is guided to the pressure piston portion of the friction plate, is particularly constructed as follows.

That is, as shown in FIG. 3, this pressure regulating valve 43 is equipped with a valve body 47 that is moved back and forth and is biased to move in the backward direction by a pressure setting spring 46 as usual.
The spring 46 is activated by the hydraulic pressure of the inlet boat 50 which is applied to the oil chamber 49 behind the valve body 47 through the outer periphery of the small diameter portion 47a of the valve body 47 and the oil hole 48 formed in the valve body 47.
When it is moved forward to the chain line position shown in the figure against the spring force, a gap is caused to pass between the inlet boat 50 and the outlet boat 51 at the outer circumferential tip position of the small flap part 47a, and oil is relieved in the direction of the outlet boat 51. However, according to the present invention, the tip of the pressure setting spring 46 in the pressure regulating valve 43 is supported by a control piston 52 that can move forward and backward, and is moved in the backward direction by the spring 46 and another compression spring 53. Behind this energized control piston 52 is a partition member 5.
4 forms an oil chamber 55, and an oil passage 56,
An oil chamber 57 in the partition member 54 and an oil passage 5 which is an oil passage 58 bored in the partition member 54 and into which a throttle 59 is inserted.
8, the hydraulic pressure of the inlet boat 50 is applied to the oil chamber 55, and as a result of the above, the switching valve 41 is moved to the operating position F.
When switching to 1, F2, F3 or R, first the valve body 4
A low oil pressure corresponding to the compression amount of the spring 46 corresponding to the position shown by the chain line 7 is established in the oil supply circuit 40, and then the oil pressure of the inlet boat 50 is gradually applied to the bottle chamber 55 behind the control piston 52 via the throttle 59. As the control piston 52 is gradually advanced to compress the pressure setting spring 46 to zero, the pressure of the spring 4 increases due to the compression.
The oil pressure of the oil supply circuit 40 is gradually increased corresponding to the strength of 6. In the illustrated case, a reciprocating rod 61, which passes through the valve case cover 60 at one end of the steel pressure valve 43 and the partition wall member 54, is brought into contact with the rear end surface of the control piston 52 with its tip. A cam disk 63 is configured such that the last retreating pupil of the control piston 52 can be changed by advancing and retreating the advancing and retreating rod 61, and is rotatable around the support shaft 62.
is provided with its cam surface abutting against the rear end of the reciprocating rod 61, and is provided with rack teeth 65 that mesh with pinion teeth 64 formed on a part of the circumferential surface of the cam disk 63. Pestle 6
6 is provided, and by moving the advancing/retracting village 66 back and forth in the direction of the arrow A, the force ram disk 63 can be rotated from the illustrated state in which the advancing/retracting rod 61 is brought into contact with the cam surface 63a. 6
When the rear end of the cam surface 63b or 63c is brought into contact with another cam surface 63b or 63c, the advance/retreat rod 61 is moved forward accordingly.
Correspondingly, the control piston 52 is arranged to assume its last position a certain amount forward of the position shown. Furthermore, the third
In the figure, 67 indicates the oil passage 58 in the partition wall portion 54.
This check valve 67 is inserted into another oil passage 68 drilled in parallel with the inlet boat 50, and allows oil to flow only in the direction of the inlet boat 50. Position N
'If the oil chamber 55 behind the control piston 52
69 is a drain hole for IJ-k oil. ZNext, a mechanism for advancing and retracting the advance/retreat punch 66 to change the final retraction position of the control piston 52 in the pressure regulating valve 43 will be explained with reference to FIG. The piston 52 is moved by the operator 2 of the sub-transmission device 6.
The forward and backward lever 66 is connected to the change lever 70' of the sub-transmission device 6 as follows. That is, as shown in FIG. 4, the shift gear 24,
The change lever 70 for displacing 25 and 26 is rotatable around a pin 73 that passes through a sphere 72 supported by a housing cover 71, and its lower end is connected to a sliding shaft 74, A washing bar 3-70 is installed on either side of the upper surface of a pair of washing hardware 76, 77 which is iron-bonded to the washing machine 75.
Shift forks 76a, 77a are integrally vertically disposed on the lower surfaces of the drain fittings 76, 77. 77a are fitted into the shifter fitting grooves 36, 37, respectively, so that the shift gears 24, 25, 26 can be selectively displaced by rotating the lever 70 in the longitudinal direction. spring 7 respectively
Of the two movable shafts 74, 75, the annular grooves 80a, 81 40a facing the click stop balls 80, 81 moved and energized at 8, 79 are formed on their circumferential surfaces;
A sliding shaft 74 to which a shift fork 76a for displacing the shift gear 24 for obtaining the 4th and 5th speeds of the sub-transmission device 6 or a sliding metal fitting 76 is attached is configured on the advance/retreat punch 66, When the shift gear 24 is placed in the non-operating position, the cam surface 63a acts, and when the shift gear 24 is placed in the 4-distal position, the cam surface 63b acts,
The cam surface shape is set so that the cam surface 63c acts when the shift gear 24 is placed in the fifth speed position. In FIG. 1, 82 is a bevel wheel at the end of the intermediate shaft 5, 83 is a bevel gear which is fixed to the differential cage of the differential gear 7 and is meshed with the bevel gear 82, and 91 is the differential gear 7. differential lock device, 84 and 8 for inactivating
Reference numeral 5 denotes a pair of left and right gears that interlock and connect the output shaft 7a of the rhombus drive device 7 and the axle 8a, 86 an internally expanding type pig rake disposed at the end of the output shaft 7a, and 87 and 88 the drive shaft 8a, respectively. Intermediate shaft provided on the extension line of shaft 2, 89 is PT
The O-axis 90 is a PTO transmission disposed between the intermediate shaft 88 and the PTO shaft 89.

Since the transmission device 0 for a tractor or the like according to the present invention is configured as described above, first, as described above, from the time when the switching valve 41 is switched to the operating position F1, F2, F3, R, the pressure regulating valve 48 As shown in FIG. 5, the oil pressure P of the oil supply circuit 40 is regulated by the gradual advancement of the control piston 52 at the stepped portion 92.
The oil pressure is gradually increased to a predetermined high oil pressure P2 when the maximum forward position shown by the chain line in FIG. The hydraulic clutch 18-
In addition to preventing damage to the transmission member 21 or related thereto as described above, the adverse effects of shock waves that may occur in the hydraulic circuit are also prevented, and furthermore, unpleasant shocks to the driver are also prevented. However, the transmission according to the present invention further controls the last retraction of the control piston 52 in the pressure regulating valve 43 by the operation means 70 of the sub-transmission device 6 in conjunction with the speed change operation by the operation means as described above. Since the piston 52 is interlocked and connected so that the last retracted layer of the piston 52 is changed when the piston 52 is moved forward or backward, the last retracted layer of the control piston 52 in the sea bream pressure valve 43 is changed according to the reduction ratio in the sub-transmission device 6. Adjust and
The amount of precompression of the pressure setting spring 46 and therefore the spring 46
The initial spring force of the 6th spring can be freely changed and adjusted.
As shown in the figure, the initial operating oil pressure applied to the hydraulic clutch 18-21 immediately after switching the switching valve 43 to the operating position is adjusted as indicated by PI-1, PI-2, and PI-3 in FIG. It can be changed and adjusted according to the reduction ratio in the sub-transmission device 6.

More specifically, as described above, as the equivalent inertial mass of the clutch load increases, the higher the speed stage of the transmission 6, that is, the smaller the reduction ratio, the higher the initial working oil pressure for the hydraulic clutches 18-21. is made large, so that the starting acceleration can be made almost constant regardless of the speed reduction ratio Z of the dramatic distance change device 6. As is clear from the above description, the transmission device for a tractor or the like of the present invention has two sets of transmission devices 4 and 6 arranged in series in the power transmission path from the engine 1 to the final drive means 8 such as wheels. The front-stage transmission 4 includes a drive shaft 2 located on the engine 1 side and a driven shaft 3 located on the final drive means 8 side.
A plurality of sets of speed change gear units are arranged between them, and a hydraulic clutch is arranged for each set of speed change gear units, and the hydraulic clutches 18, 19, 20,
This is a transmission device for a tractor or the like, which is configured to interlock and connect the drive ball 2 and the driven shaft 3 via a transmission gear unit that is selectively activated by the boarding of the hydraulic clutch 18, 21, and the like. The pressure regulating valve 43 sets the oil pressure of the oil supply circuit 40 into which the switching valve 41 that controls the supply of hydraulic oil to the 19, 20, and 21 is inserted.
A control piston 52 that receives the tip of the pressure setting spring 46 and changes the strength of the pressure setting spring 46 by advancing and retreating is disposed, and behind this control piston 52, the oil pressure of the oil supply circuit 40 is applied, and a throttle 59 is provided. The control piston 52 is actuated through an inserted circuit, and the control piston 52 is moved forward and backward in conjunction with the speed change operation by the operating means of the other transmission device 6.
The two last abdication layers are interlocked and connected so that they can be changed, and have the following advantages.

That is, the transmission of the present invention maintains the oil pressure of the oil supply circuit 40 for the hydraulic clutches 18, 19, 20, and 21 in one transmission 4, and therefore the respective hydraulic clutches from the time when the switching valve 41 is switched to each operating position. A pressure regulating valve 43 for setting the hydraulic pressure applied thereto is configured such that the tip of the pressure setting spring 46 is received by the control piston 52, and the hydraulic pressure of the oil supply circuit 40 is connected behind the control piston 52. is applied gradually through the throttle 59, and the strength of the pressure setting spring 46 is gradually increased by the gradual advancement of the control piston 52, thereby gradually increasing the working oil pressure for each hydraulic clutch. When operating the hydraulic clutch, it is assumed that the hydraulic clutch is operated gradually, thereby preventing damage to the hydraulic clutch and related transmission members and shock waves in the hydraulic circuit that may occur due to sudden hydraulic action. This prevents the adverse effects caused by such occurrence and also prevents unpleasant shocks to the driver.

Further, the transmission of the present invention utilizes the fact that the pressure regulating valve 43 is provided with the control piston 52 as described above, so that the last recessed layer of the control piston 52 is adjusted according to the gear position of the other transmission 6. The initial hydraulic pressure applied to the hydraulic clutch, which is determined by the last retreated layer 0 of the control piston 52, is changed in accordance with the gear position of the other transmission. The higher the transmission gear 6 is located, that is, the smaller the reduction ratio by the other transmission 6, the greater the equivalent inertial mass that acts on the hydraulic clutch operated in one transmission 4. The activation of the hydraulic clutch is delayed and the start or speed increase acceleration due to activation of the hydraulic clutch becomes 4. However, as the other transmission 6 is moved to the high speed gear side, the initial acceleration for the hydraulic clutch becomes 4. To increase the working oil pressure so that the hydraulic clutch can be operated quickly, and to always keep the starting or accelerating acceleration of the vehicle neck almost constant regardless of which gear the other transmission device 6 is in. What it does, what it becomes, and what it becomes.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, in which Fig. 1 is a transmission system diagram, Fig. 2 is a hydraulic circuit diagram, Fig. 3 is a vertical cross-sectional view of the main parts, and Fig. 4 is a diagram of other main parts. 0 and 5 are graphs showing the effect. 1...Engine, 2...Drive shaft, 3...
...Intermediate shaft (driven ball), 4...Main transmission,
6...Sub-transmission device, 8...Traveling drive wheel, 9,
10...FI gear, 11, 12...F2 gear, 13
,14...F3 gear, 15,16,17...R gear, 18...FI hydraulic clutch, 1 9...F2
Free pressure clutch, 20...F3 Free pressure clutch, 2
1...R hydraulic clutch, 40...Oil supply circuit, 4...Switching valve, 43...Humble pressure valve, 4
6... Pressure setting spring, 52... Control piston, 55... Oil chamber, 59... Throttle,
61...Advance and retreat. Tsudo, 63...Cam disc, 66...Advance/retreat village, 70...Change lever. Little brother r figure 2 figure 3 figure 4 figure 5

Claims (1)

[Claims] 1 Two sets of transmissions are arranged in series in the power transmission path from the engine to the final drive means such as wheels, and the first transmission is connected to the drive shaft located on the engine side and the final drive means side. A plurality of sets of speed change gear units are disposed between positioned driven shafts, and a hydraulic clutch is respectively disposed in each set of speed change gear units, and the transmission is selectively operated by fitting the hydraulic clutch belonging to the set. A transmission device for a tractor, etc., configured to interlock and connect the driving shaft and the driven shaft through a gear unit, and an oil supply circuit in which a switching valve for controlling supply and discharge of hydraulic oil to and from the hydraulic clutch is inserted. A control piston that receives the tip of a pressure setting spring in the pressure regulating valve and changes the strength of the pressure setting spring by advancing and retreating is disposed in the pressure regulating valve that sets the oil pressure of the pressure regulating valve, and behind the control piston the oil supply circuit is connected to the control piston. The hydraulic pressure is applied to the control piston through a circuit into which a throttle is inserted, and the control piston is moved forward and backward in conjunction with the speed change operation by the operation means of the other transmission, and the control piston is moved forward and backward in conjunction with the speed change operation by the operation means. A transmission in a tractor, etc., which is interlocked so that the abdication layer can be changed.