JP2008095749A - Transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission capable of realizing multiple main shift stages through a simple and inexpensive structure. <P>SOLUTION: The transmission comprises an input shaft 210, a main clutch output shaft 291, a pair of forward and backward hydraulic clutch mechanisms 410 and 420, two sets of gear synchronizing first and second transmission mechanisms 250 and 280, and a pair of first and second hydraulic clutch mechanisms 240 and 270. In gear shifting operation from one odd shift stage to the other odd shift stage or one even shift stage to the other even shift stage by the two sets of first and second transmission mechanisms 250 and 280, the pair of forward and backward hydraulic clutch mechanisms 410 and 420 are operatively connected with a reverser lever 114 and a clutch pedal 123 to form a main clutch. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transmission technology.

  Conventionally, transmission technology is known. For example, in Patent Document 1, the second gear speed change mechanism is operated to a predetermined shift position, the first friction clutch is operated to be disconnected while the second friction clutch is operated to the transmission state, and the transmission clutch is moved from the transmission state. First control means for operating in the semi-transmission state and gradually operating in the transmission state is provided, the second gear clutch is operated while operating the first gear transmission mechanism to a predetermined shift position and operating the first friction clutch in the transmission state. Is operated to turn off, and the transmission clutch is operated from the transmission state to the half transmission state and gradually moved to the transmission state, and the first and second control units are operated alternately to change the speed command. A transmission comprising third control means for obtaining a shift position according to the above is disclosed.

According to the transmission, in the traveling speed change structure of the work vehicle, the double transmission state is generated while the speed change operation is performed, and the power with less torque fluctuation is transmitted to the traveling device. It is possible to prevent a situation where a shock is generated when the transmission clutch is operated to a transmission state in a state where the traveling speed of the aircraft drastically decreases due to a traveling load and the traveling speed of the aircraft greatly decreases. Performance and speed change performance can be improved.
JP 2003-314679 A

  However, in order to cope with the multi-stage main shift by no-clutch shift, a hydraulic clutch (power shift clutch) corresponding to the main gear shift is required, which increases the size of the transmission and the cost. In addition, the control device for controlling all the clutches has become complicated, and the control valve has become large.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a transmission that achieves multi-stage main shift with a simple and inexpensive configuration.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

That is, in claim 1,
A transmission in which power is shifted and transmitted from a drive source to drive wheels,
An input shaft operatively connected to the drive source;
A transmission shaft arranged parallel to the input shaft;
A pair of reverser clutches arranged on the input shaft and for switching the rotational direction of the power transmitted to the transmission shaft;
Two sets of gear-synchronized main transmissions arranged on the output side of the pair of reverser clutches;
A pair of clutches that are arranged on the output side of the two sets of main transmissions and that switch between connection and disconnection of power transmitted from each of the two sets of main transmissions;
In the shifting operation from one odd gear to another odd gear, or from one even gear to another even gear by the two sets of main transmissions, the pair of reverser clutches includes a reverser lever and a clutch pedal. Is linked to the main clutch.

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect of the present invention, since the forward / reverse switching and the main shift switching can be switched without a clutch without providing a hydraulic clutch at each shift stage as in the conventional hydraulic clutch transmission, it is necessary to provide a separate main clutch. Because the clutch can be configured inexpensively and compactly, and the clutch is arranged on the output side of the main transmission, the clutch load can be reduced and the clutch can be made smaller, so the transmission case can be configured compactly. The transmission can be made compact at low cost.

  Hereinafter, preferred embodiments of a transmission according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side view showing a traveling vehicle to which a transmission according to the present embodiment is applied, FIG. 2 is a skeleton diagram of a transmission according to a first embodiment, and FIG. 3 is a diagram illustrating a first hydraulic clutch mechanism from a hydraulic mechanism during a shifting operation. And FIG. 4 is a plan view of the main transmission lever, FIG. 5 is a plan view of the reverser lever, FIG. 6 is a reverser lever, main transmission lever, FIG. 7 is a diagram showing an operation system of a clutch pedal, first and second hydraulic clutch mechanisms, first and second transmission mechanism shifters, and forward and reverse hydraulic clutch mechanisms, and FIG. 7 is a skeleton diagram of a transmission according to the second embodiment. is there.

  First, the transmission 200 of the first embodiment will be described with reference to FIGS. A traveling vehicle (tractor) 100 shown in FIG. 1 includes a main body 103 that suspends a pair of left and right front wheels 101 and 101 and a pair of left and right rear wheels (drive wheels) 102 and 102 in the front and rear of the vehicle. A bonnet 106 is disposed at the front, and a drive source (here, an engine) 105 is disposed inside the bonnet 106. A driver's seat 107 is provided in the cabin 104. A main transmission lever 110 projects from a side portion of the driver's seat 107, and a steering handle 108 is disposed in front thereof. A reverser lever 114 that is an operation lever for switching between forward and reverse travel of the traveling vehicle 100 is disposed on the left side of the handle column 115, and a clutch pedal 123 is disposed on the floor below the lever.

  The traveling vehicle 100 is provided with a transmission case 109 provided with a transmission 200 behind the drive source 105, and transmits power from the drive source 105 to the transmission 200 for shifting. Here, a rear wheel (drive wheel) is used. ) 102 and 102 are configured to be able to transmit driving force. The traveling vehicle 100 is mounted with a work machine (not shown) via a work machine mounting device having a top link 112 and a lower link 113 at the rear, and a part of the power from the drive source 105 is transmitted to the transmission case. The PTO shaft 111 protruding from the rear surface 109 is transmitted to the working machine via a telescopic transmission shaft (not shown) provided with universal joints at both ends to drive the working machine.

  Next, the transmission 200 will be described in detail. As shown in FIG. 2, the transmission 200 is inserted in a traveling system transmission path from the drive source 105 to the drive wheels 102, 102, and includes an input shaft 210, a forward hydraulic clutch mechanism 410, and a reverse hydraulic clutch. Mechanism 420, reverse transmission shaft 290, main clutch output shaft 291, main transmission shaft 292, first transmission mechanism 250, first transmission shaft 230, first hydraulic clutch mechanism 240, and second transmission mechanism 280, a second transmission shaft 260, and a second hydraulic clutch mechanism 270. Here, the forward hydraulic clutch mechanism 410 and the reverse hydraulic clutch mechanism 420 are the main clutches. The main clutch is a clutch having a performance capable of absorbing the total horsepower of the drive source (engine) 105.

  The input shaft 210 is a single input shaft that is operatively connected to the output shaft of the drive source 105. A pipe-shaped main clutch output shaft 291 is loosely fitted on the input shaft 210, and the main clutch output shaft. A front portion of the pipe-shaped main transmission shaft 292 is spline-fitted (or fixed) on the rear portion of the 291. The rear portion of the input shaft 210 is connected to the PTO shaft 111, and a pipe-shaped sub-transmission transmission shaft 516 is loosely fitted on the rear portion of the input shaft 210 (or the PTO shaft 111). The shaft 291, the main transmission shaft 292, the PTO shaft 111, and the sub-transmission transmission shaft 516 are disposed on the same axis. In this way, a plurality of shafts are arranged on one shaft center, and a clutch and a transmission are arranged on the shaft, thereby realizing a compact size.

  In addition, a reverse transmission shaft 290 is disposed in parallel with the input shaft 210, a main transmission output shaft 910 is disposed behind the reverse transmission shaft 290, and a pipe-shaped first shaft is disposed on the front of the main transmission output shaft 910. 1 a transmission shaft 230 is loosely fitted, a pipe-like second transmission shaft 260 is loosely fitted on the rear portion of the main transmission output shaft 910, an output shaft 960 is disposed behind the main transmission output shaft 910, and reverse transmission The shaft 290, the main transmission output shaft 910, the first transmission shaft 230, the second transmission shaft 260, and the output shaft 960 are disposed on the same shaft center.

  A main clutch including a pair of front and rear hydraulic clutches is disposed on the input shaft 210. The main clutch has a forward hydraulic clutch mechanism 410 disposed at the rear, and a reverse hydraulic clutch mechanism 420 disposed at the front. ing. Two sets of main transmissions are disposed between the main transmission shaft 292 and the first transmission shaft 230 and between the main transmission shaft 292 and the second transmission shaft 260, respectively. The odd speeds of the first speed and the third speed and the even speed stages of the second speed and the fourth speed are arranged in front and rear. Note that the odd-numbered gear stage and the even-numbered gear stage may be arranged in the reverse order. More specifically, an odd-numbered first shift mechanism 250 is disposed on the front of the main transmission shaft 292, and an even-numbered second shift mechanism 280 is disposed on the rear thereof. A sub-transmission mechanism 500 is disposed between the rear portion of the main transmission output shaft 910, the sub-transmission transmission shaft 516, and the output shaft 960. On the other hand, a forward drive transmission mechanism 118 composed of a gear mechanism is disposed between the main clutch (forward hydraulic clutch mechanism 410) and the main clutch output shaft 291, and the main clutch (reverse hydraulic clutch mechanism 420) and A reverse drive transmission mechanism 119 configured by a gear mechanism is disposed between the main clutch output shafts 291.

  In the forward hydraulic clutch mechanism 410, a multi-plate hydraulic clutch is formed between the input shaft 210 and the main clutch output shaft 291, and the reverse hydraulic clutch mechanism 420 is interposed between the input shaft 210 and the boss portion of the reverse gear 122. A multi-plate hydraulic clutch is formed. The forward drive transmission mechanism 118 is directly transmitted from the forward hydraulic clutch mechanism 410 to the main clutch output shaft 291 and the main transmission shaft 292. In the reverse drive transmission mechanism 119, the reverse gear 122 loosely fitted on the input shaft 210 is engaged with the reverse first driven gear 940 fixed on the reverse drive shaft 290 via the intermediate idle gear 430. Further, the reverse second driven gear 920 fixed on the reverse transmission shaft 290 behind the reverse first driven gear 940 is engaged with the reverse third driven gear 121 loosely fitted on the input shaft 210, Power is transmitted from the reverse gear 122 to the main clutch output shaft 291. The forward hydraulic clutch mechanism 410 and the reverse hydraulic clutch mechanism 420 are integrally formed front and rear on a concentric shaft. The reverse third driven gear 121 and the reverse gear 122 are disposed on both the front and rear sides with the forward hydraulic clutch mechanism 410 and the reverse hydraulic clutch mechanism 420 interposed therebetween. In this embodiment, the main clutch is constituted by a multi-plate hydraulic clutch, but it can also be constituted by a powder type clutch.

  A first speed gear mechanism 251a and a third speed gear mechanism 251b are disposed between the first speed change mechanism 250 and the front part of the first transmission shaft 230, and the second speed change mechanism 280 and the front part of the second transmission shaft 260 are disposed. Between the second speed gear mechanism 281a and the fourth speed gear mechanism 281b.

  A pair of front and rear hydraulic clutches for main transmission are arranged on the main transmission output shaft 910. The hydraulic clutch has a second hydraulic clutch mechanism 270 at the front, and a first hydraulic clutch mechanism 240 at the rear. Has been placed. Further, a second speed gear mechanism 281a and a fourth speed gear mechanism 281b configured by a gear mechanism are disposed between the first hydraulic clutch mechanism 240 and the rear portion of the main transmission shaft 292, and the second hydraulic clutch mechanism 270 and the main transmission are shifted. A first speed gear mechanism 251a and a third speed gear mechanism 251b configured by a gear mechanism are disposed between the front portions of the shaft 292. That is, the first and second hydraulic clutch mechanisms 240 and 270 include the first speed change mechanism 250 (first speed gear mechanism 251a and third speed gear mechanism 251b) and the second speed change mechanism 280 (second speed gear mechanism 281a and second speed gear mechanism 281a). The fourth-speed gear mechanism 281b) is arranged symmetrically in the front-rear direction (substantially in the center).

  Specifically, in the first speed gear mechanism 251a, a first drive gear 261 that is loosely fitted to the front portion on the main transmission shaft 292 is integrally provided on the input side of the second hydraulic clutch mechanism 270 to provide a first transmission. It is meshed with a first driven gear 230a fixed on the shaft 230 so that power can be transmitted. In the third speed gear mechanism 251b, a third drive gear 263 that is loosely fitted on the main transmission shaft 292 in front of the first drive gear 261 is integrally provided on the input side of the second hydraulic clutch mechanism 270. Thus, it is meshed with a third driven gear 230b fixed on the first transmission shaft 230 so that power can be transmitted. In the second speed gear mechanism 281a, a second drive gear 262 that is loosely fitted on the rear portion of the main transmission shaft 292 is integrally provided on the input side of the first hydraulic clutch mechanism 240, and the second transmission shaft 260 is provided. It is meshed with a second driven gear 260a fixed on the top so that power can be transmitted. In the fourth speed gear mechanism 281b, a fourth drive gear 264 that is loosely fitted on the main transmission shaft 292 behind the second drive gear 262 is integrally provided on the input side of the first hydraulic clutch mechanism 240. Thus, it is meshed with a fourth driven gear 260b fixed on the second transmission shaft 260 so that power can be transmitted. A second hydraulic clutch mechanism 270 is formed between the first driven gear 230a and the third driven gear 230b and the main transmission output shaft 910, and the second driven gear 260a and the fourth driven gear 260b and the main transmission output shaft 910 are formed. A first hydraulic clutch mechanism 240 is formed between the first hydraulic clutch mechanism 240 and the first hydraulic clutch mechanism 240 and the second hydraulic clutch mechanism 270, which are integrally formed on the concentric shaft. The first driven gear 230a, the third driven gear 230b, the second driven gear 260a, and the fourth driven gear 260b are disposed on both front and rear sides with the first hydraulic clutch mechanism 240 and the second hydraulic clutch mechanism 270 interposed therebetween. In this embodiment, the clutch is constituted by a multi-plate type hydraulic clutch, but it can also be constituted by a powder type clutch or the like.

  Thus, the first transmission path 200a is formed from the first speed change mechanism 250 to the second hydraulic clutch mechanism 270 via the first speed gear mechanism 251a or the third speed gear mechanism 251b. A second transmission path 200b is formed between the second speed gear mechanism 281a or the fourth speed gear mechanism 281b and the first hydraulic clutch mechanism 240. As described above, the transmission path from the main transmission shaft 292 to the main transmission output shaft 910 includes the first transmission path 200a and the second transmission path 200b, thereby forming a compact transmission with a simple transmission path configuration. It becomes possible.

  As described above, in the present invention, the main clutch, the main transmission mechanism, the first and second hydraulic clutch mechanisms 240 and 270, and the auxiliary transmission mechanism 500 are arranged on two axes, so that a compact transmission path configuration can be achieved. It is possible to configure a simple transmission.

  The forward and reverse hydraulic clutch mechanisms 410 and 420 have a well-known hydraulic multi-plate clutch structure, and switch the control valve (electromagnetic valves 624 and 625) based on an external operation (reverser lever 114 operation) to send pressure oil. The forward hydraulic clutch mechanism 410 or the reverse hydraulic clutch mechanism 420 is “connected” or “disconnected”, and the rotational power of the input shaft 210 is selectively transmitted to the main clutch output shaft 291. Yes. When the forward hydraulic clutch mechanism 410 is “connected” and the reverse hydraulic clutch mechanism 420 is “disconnected”, the rotational power of the input shaft 210 is transmitted from the forward hydraulic clutch mechanism 410 to the main clutch output shaft 291. On the other hand, when the forward hydraulic clutch mechanism 420 is “contacted” and the forward hydraulic clutch mechanism 410 is “disengaged”, the rotational power of the input shaft 210 is for backward travel. Via the hydraulic clutch mechanism 420 and the reverse drive transmission mechanism 119, the rotational direction of the forward hydraulic clutch mechanism 410 is switched to be transmitted to the main clutch output shaft 291.

  Further, each of the first transmission mechanism 250 and the second transmission mechanism 280 includes a plurality of transmission mechanisms, and is configured to obtain a plurality of speed ratios. Each of the first transmission mechanism 250 and the second transmission mechanism 280 is a synchronous mesh type multi-stage transmission mechanism (synchromesh type transmission mechanism) configured to perform transmission in a state where the driving gear and the driven gear are previously engaged with each other. Yes. More specifically, an odd-numbered gear (or even-numbered gear) synchronous mesh type multi-speed transmission mechanism is arranged at the front of the main transmission shaft 292, and an even-numbered gear (or odd-numbered gear) is a synchronously meshed multi-speed gearshift at the rear. The mechanism is arranged. In the present embodiment, a transmission mechanism (first transmission mechanism 250) for odd-numbered gears of the third speed and the first speed is arranged at the front, and a transmission mechanism for even-numbered gears of the second and fourth speeds (the first gear mechanism 250) is arranged at the rear. A second transmission mechanism 280) is disposed.

  Then, the third drive gear 263 and the first drive gear 261 are loosely fitted on the front portion on the main transmission shaft 292, and the first transmission mechanism shifter 252 is spline-fitted on the main transmission shaft 292 therebetween, and the shaft It is slidable in the direction and is fitted so as not to be relatively rotatable, and can be selected as the third speed or the first speed by sliding forward or backward by operation of the speed change operation means. The second drive gear 262 and the fourth drive gear 264 are loosely fitted on the rear portion of the main transmission shaft 292, and the second transmission mechanism shifter 282 is spline-fitted on the main transmission shaft 292 therebetween, so that the axial direction And can be selected as the second speed or the fourth speed by sliding forward or backward by the operation of the speed change operation means. The first speed change mechanism shifter 252 and the second speed change mechanism shifter 282 are both frictional double synchronous clutches.

  The first and second hydraulic clutch mechanisms 240 and 270 have a well-known hydraulic multi-plate clutch structure, and switch the control valve (electromagnetic valves 620 and 621) based on an external operation (main shift lever 110 operation) to pressurize the pressure oil. , The first hydraulic clutch mechanism 240 or the second hydraulic clutch mechanism 270 is “contacted”, and the rotational power of the main transmission shaft 292 is output to the main transmission via the first transmission shaft 230 or the second transmission shaft 260. It is configured to selectively transmit to the shaft 910. In this embodiment, the first hydraulic clutch mechanism 240 connects / disconnects even-numbered gears, and the second hydraulic clutch mechanism 270 connects / disconnects odd-numbered gears. It is also possible to connect and disconnect even-numbered gears with the second and second hydraulic clutch mechanisms 270. In this way, it is possible to connect and disconnect the two sets of main transmissions on the two shaft centers, thereby forming a compact transmission.

  Further, since the first and second hydraulic clutch mechanisms 240 and 270 are arranged in oil as shown in FIG. 2, no special lubrication means is required, and the first speed change mechanism 250 and the second speed change mechanism are provided. By arranging symmetrically between the mechanisms 280 (substantially in the center), the hydraulic clutch can be simply configured, and the arrangement of the hydraulic clutch is easy.

  As illustrated in FIG. 6, the traveling vehicle 100 includes a control device 600, and the control device 600 includes a speed change mechanism (250 in one of the first transmission path 200 a and the second transmission path 200 b (200 a or 200 b). Or 280) is brought into the engaged state of the shift stage according to the first external operation (the operation of the main speed change lever 110), and the speed change mechanism (280 or 250) in the other transmission path (200b or 200a) is brought into the disengaged state. At the same time, the hydraulic clutch mechanism (270 or 240) in one transmission path (200a or 200b) is set to the power transmission state, and the hydraulic clutch mechanism (240 or 270) in the other transmission path (200b or 200a) is set to the power cutoff state. After that, when the next second external operation (main shift lever 110 operation) is performed, The speed change mechanism (280 or 250) in the other power transmission path (200b or 200a) is maintained while the speed change mechanism (250 or 280) in the power transmission path (200a or 200b) is kept in the engaged state of the speed stage according to the first external operation. ) Is brought into the engaged state of the shift stage according to the second external operation, and the hydraulic clutch mechanism (270 or 240) in one transmission path (200a or 200b) is gradually shifted from the power transmission state to the power cutoff state. At the same time, the hydraulic clutch mechanism (240 or 270) in the other transmission path (200b or 200a) is gradually shifted from the power cutoff state to the power transmission state. Specifically, the control device 600 includes a central processing unit (CPU) and a storage unit. The storage unit stores a control program, and includes, for example, a ROM and a RAM.

  Further, the control device 600 puts one hydraulic clutch mechanism (410 or 420) according to an external operation (reverser lever 114 operation) into a power transmission state, and puts the other hydraulic clutch mechanism (420 or 410) into a power cut-off state. After that, when the next external operation (reverser lever 114 operation) is performed, the other hydraulic clutch mechanism (420 or 410) is set in the power transmission state, and one hydraulic clutch mechanism (410 or 420) is set in the power cut-off state. It is configured to be

  The control device 600 includes electromagnetic valves 620, 621, 622, 623, 624, and 625, detection means 610 for detecting the shift position of the main transmission lever 110, detection means 611 for detecting the lever position of the reverser lever 114, A detecting means 612 for detecting the depression position of the clutch pedal 123 is connected.

  The electromagnetic valves 620, 621, 624, and 625 actuate solenoids to switch the direction in which the hydraulic oil is fed from the hydraulic pump, and the first hydraulic clutch mechanism 240, the second hydraulic clutch mechanism 270, or the forward hydraulic clutch mechanism 410. Alternatively, the reverse hydraulic clutch mechanism 420 is connected or disconnected. At this time, the electromagnetic valves 620, 621, 624, and 625 are PWM-controlled to change the oil feed amount. However, the electromagnetic valves 620, 621, 624, and 625 can also be configured as electromagnetic proportional valves, and in this case, the oil supply amount can be changed by adjusting the applied voltage from the control device 600. .

  The electromagnetic valves 622 and 623 actuate solenoids to switch the direction of oil supply from the hydraulic pump, and slide actuators 630 and 631 such as cylinders to shift the first speed change mechanism shifter 252 and the second speed change. The main shift device can be shifted from the first speed to the fourth speed by sliding the mechanism shifter 282. It should be noted that an actuator such as a solenoid or a motor may be applied instead of the electromagnetic valves 622 and 623 and the actuators 630 and 631.

  Next, a specific example of forward / reverse switching will be described. The drive source 105 is always in a rotating state after startup, and therefore the input shaft 210 is always in a rotating state around the axis.

  When the reverser lever 114 is operated from the neutral position N to the forward position F, the electromagnetic valve 624 is switched, the forward hydraulic clutch mechanism 410 is “contacted”, and the reverse hydraulic clutch mechanism 420 remains “disconnected”. The rotational power of the input shaft 210 is transmitted to the main clutch output shaft 291 via the forward hydraulic clutch mechanism 410.

  Next, when the reverser lever 114 is operated from the forward position F to the reverse position R, the electromagnetic valve 625 is switched, and the forward hydraulic clutch mechanism 420 is “disconnected” and then the reverse hydraulic clutch mechanism 420 is “closed”. Thus, the rotational power of the input shaft 210 is transmitted to the main clutch output shaft 291 through the reverse hydraulic clutch mechanism 420 and the reverse drive transmission mechanism 119 while switching the rotation direction with the forward hydraulic clutch mechanism 410. Specifically, from the input shaft 210, the reverse hydraulic clutch mechanism 420, the reverse drive transmission mechanism 119, the reverse gear 122, the intermediate idle gear 430, the reverse first driven gear 940, the reverse drive shaft 290, the reverse second driven gear 920, Power is transmitted to the main clutch output shaft 291 by being transmitted to the reverse third driven gear 121.

  With such a configuration, the transmission 200 can switch forward and backward travel of the traveling vehicle 100.

  The electromagnetic valves 624 and 625 for operating the pair of forward hydraulic clutch mechanisms 410 and the reverse hydraulic clutch mechanism 420 constituting the reverser clutch (main clutch) are interlocked with the reverser lever 114 and the clutch pedal 123. When the clutch pedal 123 is depressed, the signal from the detection means 612 is input to the control device 600, the electromagnetic valves 624 and 625 are turned OFF, the forward and reverse hydraulic clutch mechanisms 410 and 420 are turned off, and the power is The clutch output shaft 291 is not transmitted.

  Next, a specific example of the speed change operation will be described. As described above, the drive source 105 is always rotated after starting, and the input shaft 210 is always rotated around the axis. Therefore, in the state where the forward hydraulic clutch mechanism 410 or the reverse hydraulic clutch mechanism 420 is in the “contact” state, the main clutch output shaft 291 is always rotated around the axis as described above, and the main clutch output shaft 291 is in a rotating state. The main transmission shaft 292 is also always rotated around the axis via the clutch output shaft 291.

  In the state where the forward hydraulic clutch mechanism 410 or the reverse hydraulic clutch mechanism 420 is in the “contact” state, first, when the main transmission lever 110 is shifted from the neutral position N to the first speed, the electromagnetic valve 622 is switched, By actuating the actuator 630, the first speed change mechanism shifter 252 is slid and meshed with the teeth of the first drive gear 261 in the first speed gear mechanism 251a, and the first driven gear 261 to the first driven gear. Power can be transmitted to the first transmission shaft 230 via 230a. At the same time, the electromagnetic valve 621 is switched to make the second hydraulic clutch mechanism 270 “contact”, and power is transmitted from the main transmission shaft 292 to the main transmission output shaft 910 via the first transmission path 200a. . Specifically, the first transmission shifter 252, the first drive gear 261, the first driven gear 230 a, the first transmission shaft 230, and the second hydraulic clutch mechanism 270 are transmitted from the main transmission shaft 292 to the main transmission output shaft 910. Is transmitted. Power is transmitted from the main transmission output shaft 910 to the rear wheels (drive wheels) 102 and 102 via the auxiliary transmission mechanism 500 and the differential device 900. On the other hand, in the second transmission path 200b, since the first hydraulic clutch mechanism 240 is “disconnected”, the rotational power from the main transmission shaft 292 to the main transmission output shaft 910 is not transmitted.

  Next, when the main speed change lever 110 is shifted from the first speed to the second speed, the electromagnetic valve 623 is switched, the actuator 631 is operated, and the second speed change mechanism shifter 282 is slid to move the second drive gear. Engaged with the tooth portion of 262, power can be transmitted from the main transmission shaft 292 to the second drive gear 262. At the same time, the operating voltage to the electromagnetic valve 621 is gradually decreased, the operating voltage to the electromagnetic valve 620 is gradually increased, and the operating oil pressure fed to the second hydraulic clutch mechanism 270 as shown in FIG. α is gradually decreased, and the hydraulic pressure β fed to the first hydraulic clutch mechanism 240 is gradually increased. For example, in the first speed shift state (see γ1), the second hydraulic clutch mechanism 270 is “contact”, and the first hydraulic clutch mechanism 240 is “disconnected”. In the transitional period when shifting from the first speed to the second speed (see γ2), the hydraulic pressure to the second hydraulic clutch mechanism 270 decreases and the hydraulic pressure to the first hydraulic clutch mechanism 240 increases. The first hydraulic clutch mechanism 240 and the second hydraulic clutch mechanism 270 are both “contacted” while sliding, and are in a so-called half-clutch state, and power is transmitted to the first transmission path 200a and the second transmission path 200b. .

  Then, in a state where the predetermined speed has elapsed and the gear has been completely shifted to the second speed (see γ3), the supply of hydraulic oil to the second hydraulic clutch mechanism 270 is stopped and becomes “off”, and the first hydraulic clutch The working hydraulic pressure to the mechanism 240 becomes the set hydraulic pressure and becomes “contact”. Then, power is not transmitted to the first transmission path 200a, but power is transmitted to the second transmission path 200b. Specifically, the second transmission shifter 282, the second drive gear 262, the second driven gear 260a, the second transmission shaft 260, and the first hydraulic clutch mechanism 240 are transmitted from the main transmission shaft 292 to the main transmission output shaft 910. Is transmitted. At the same time, the electromagnetic valve 622 is switched to operate the actuator 630, and the first shift mechanism shifter 252 is slid to the neutral side.

  Further, when the main speed change lever 110 is changed from the second speed to the third speed, the electromagnetic valve 622 is switched, the actuator 630 is operated, and the first speed change mechanism shifter 252 is slid, and the third speed gear. The gear is engaged with the tooth portion of the third drive gear 263 in the mechanism 251b, and power is transmitted from the main transmission shaft 292 to the third drive gear 263, and the operating hydraulic pressure to the first hydraulic clutch mechanism 240 is reduced, so that The electromagnetic valves 621 and 620 are switched so as to increase the operating hydraulic pressure to the two-hydraulic clutch mechanism 270. Thus, as described above, the half-clutch state is revealed, and power is transmitted to the first transmission path 200a and the second transmission path 200b.

  Then, in a state where the predetermined time has elapsed and the gear is completely shifted to the third speed (see γ3), the supply of hydraulic oil to the first hydraulic clutch mechanism 240 is stopped and becomes “OFF”, and the second hydraulic clutch The working oil pressure to the mechanism 270 becomes the set oil pressure and becomes “contact”. Then, power is not transmitted to the second transmission path 200b, but power is transmitted to the first transmission path 200a. Specifically, the first transmission shifter 252, the third drive gear 263, the third driven gear 230 b, the first transmission shaft 230, and the second hydraulic clutch mechanism 270 are transmitted from the main transmission shaft 292 to the main transmission output shaft 910. Is transmitted. At the same time, the electromagnetic valve 623 is switched to operate the actuator 631, and the second shift mechanism shifter 282 is slid to the neutral side.

  Here, of the first to fourth shifts, the case of shifting from the first shift to the second shift and the case of shifting from the second shift to the third shift have been described as examples, but the same shift operation is performed. It is possible to switch from the third shift to the fourth shift. When shifting to the fourth shift, in the second transmission path 200b, the main transmission shaft 292 to the second transmission shifter 282, the fourth drive gear 264, the fourth driven gear 260b, the second transmission shaft 260, the first A transmission path for the fourth shift is formed which is transmitted to the hydraulic clutch mechanism 240 and passes through the main shift output shaft 910.

  A specific example of the shift operation from the first shift to the third shift will be described. As described above, in the state of being shifted to the first speed change, the first speed change mechanism shifter 252 is engaged with the tooth portion of the first drive gear 261 in the first speed gear mechanism 251a, and the first drive gear 261 to the first speed change. Power can be transmitted to the first transmission shaft 230 via the first driven gear 230a, the first hydraulic clutch mechanism 240 is “disconnected”, and the second hydraulic clutch mechanism 270 is “contacted”. Specifically, the first transmission shifter 252, the first drive gear 261, the first driven gear 230 a, the first transmission shaft 230, and the second hydraulic clutch mechanism 270 are transmitted from the main transmission shaft 292 to the main transmission output shaft 910. A transmission path for the first speed change is formed. On the other hand, in the forward and reverse hydraulic clutch mechanisms 410 and 420, the forward hydraulic clutch mechanism 410 or the reverse hydraulic clutch mechanism 420 is "contacted", and the reverse hydraulic clutch mechanism 420 or the forward hydraulic clutch mechanism 410 is " The rotational power of the input shaft 210 is selectively transmitted to the main transmission shaft 292 via the main clutch output shaft 291 as described above.

  When the main speed change lever 110 is shifted from the first speed to the third speed, the second hydraulic clutch mechanism 270 continues to be “contacted”, and the first hydraulic clutch mechanism 240 remains “disconnected”. The forward hydraulic clutch mechanism 410 (or the reverse hydraulic clutch mechanism 420) that is in the “contact” state is “disconnected”. At the same time, the electromagnetic valve 622 is switched, the actuator 630 is operated, the first speed change mechanism shifter 252 is slid, and is meshed with the tooth portion of the third drive gear 263 in the third speed gear mechanism 251b. Thus, power can be transmitted from the main transmission shaft 292 to the third drive gear 263, and the forward hydraulic clutch mechanism 410 (or the reverse hydraulic clutch mechanism 420) that has been "disconnected" is again "contacted". . In this way, the main transmission output shaft 910 is transmitted from the main transmission shaft 292 to the first transmission shifter 252, the third drive gear 263, the third driven gear 230 b, the first transmission shaft 230, and the second hydraulic clutch mechanism 270. A transmission path of the third speed change passing through is formed.

  Here, the case of shifting from the first shift to the third shift has been described as an example, but it is possible to switch from the second shift to the fourth shift by a similar shift operation. Specifically, when the main transmission lever 110 is shifted from the second speed to the fourth speed, the first hydraulic clutch mechanism 240 continues to be “contacted” and the second hydraulic clutch mechanism 270 remains “disconnected”. Thus, the forward hydraulic clutch mechanism 410 (or the reverse hydraulic clutch mechanism 420) that is “contacted” is “disconnected”. At the same time, the electromagnetic valve 623 is switched, the actuator 631 is operated, the second speed change mechanism shifter 282 is slid, and meshed with the teeth of the fourth drive gear 264 in the fourth speed gear mechanism 281b. Thus, power can be transmitted from the main transmission shaft 292 to the fourth drive gear 264, and the forward hydraulic clutch mechanism 410 (or the reverse hydraulic clutch mechanism 420) that has been "disconnected" is again "contacted". . In this way, the transmission path of the second speed change is changed to the transmission path of the fourth speed change.

  In addition to the above-described configuration, the transmission 200 according to the present embodiment includes a sub-transmission mechanism 500 that performs multi-stage transmission between the main transmission output shaft 910 and the output shaft 960 (here, the main drive shaft of the differential device 900). It has more. Specifically, the output shaft 960 is disposed substantially parallel to the main transmission output shaft 910 and is supported coaxially by the main transmission output shaft 910 so as to be rotatable about a longitudinal axis. Here, the subtransmission mechanism 500 is configured to perform a four-speed shift, and includes a subtransmission mechanism gear transmission mechanism 510, a first subtransmission mechanism shifter 520, and a second subtransmission mechanism shifter 540. It has.

  The gear transmission mechanism 510 for the subtransmission mechanism is configured to transmit power from the main transmission output shaft 910 to the output shaft 960 at a predetermined transmission ratio (here, a reduction ratio). Specifically, the sub-transmission mechanism gear transmission mechanism 510 includes a sub-transmission transmission shaft 516 disposed substantially parallel to the main transmission output shaft 910 and the output shaft 960, and first and second transmission gears having a predetermined reduction ratio. , Third sub-transmission gear mechanism 511, 512, 513 and creep transmission gear mechanism 514. Here, the first sub-transmission gear mechanism 511 includes a first sub-transmission gear 511a that is rotatably supported on the output shaft 960, and a second sub-transmission gear that meshes with the first sub-transmission gear 511a. 511b, and a second sub-transmission gear 511b provided on the sub-transmission transmission shaft 516 so as not to be relatively rotatable. Here, the second sub-transmission gear mechanism 512 includes a third sub-transmission gear 512a that is rotatably supported on the output shaft 960, and a fourth sub-transmission gear that meshes with the third sub-transmission gear 512a. 512b, and a fourth sub-transmission gear 512b provided on the sub-transmission transmission shaft 516 so as not to be relatively rotatable. Here, the third sub-transmission gear mechanism 513 includes a fifth sub-transmission gear 513a that is provided on the main transmission output shaft 910 so as not to rotate relative thereto, and a sixth sub-transmission gear that meshes with the fifth sub-transmission gear 513a. And a sixth sub-transmission gear 513b provided on the sub-transmission transmission shaft 516 so as not to be relatively rotatable. The creep transmission gear mechanism 514 is a seventh auxiliary transmission that is rotatably supported on the output shaft 960 from the second auxiliary transmission gear 511b fixed on the auxiliary transmission transmission shaft 516 via the creep gear mechanism 514b. Power is transmitted to the gear 514a.

  The first sub-transmission mechanism shifter 520 is spline-fitted on the output shaft 960, is slidable in the axial direction, and is externally fitted so as not to be relatively rotatable. The main transmission output shaft is operated by operating the sub-transmission operation means. 910 and the third auxiliary transmission gear 512a are selectively slid forward or backward. The first sub-transmission mechanism shifter 520 is engaged with the tooth portion at the end of the main transmission output shaft 910 so that the rotational power of the main transmission output shaft 910 can be transmitted to the output shaft 960. Further, by engaging the first sub-transmission mechanism shifter 520 with the tooth portion of the third sub-transmission gear 512a, the rotational power of the main transmission output shaft 910 is converted into the fifth sub-transmission gear 513a and the sixth sub-transmission gear. 513b, the sub-transmission transmission shaft 516, the fourth sub-transmission gear 512b, the third sub-transmission gear 512a, and the first sub-transmission mechanism shifter 520 can be transmitted to the output shaft 960.

  The second sub-transmission mechanism shifter 540 is spline-fitted onto the output shaft 960, is slidable in the axial direction, and is externally fitted so as not to be rotatable relative to the first sub-transmission operation means. The first gear 511a and the seventh auxiliary gear 514a are selectively slid forward or rearward. By engaging the second sub-transmission mechanism shifter 540 with the teeth of the first sub-transmission gear 511a, the rotational power of the main transmission output shaft 910 is supplied to the fifth sub-transmission gear 513a and the sixth sub-transmission gear 513b. The sub-transmission transmission shaft 516, the second sub-transmission gear 511b, the first sub-transmission gear 511a, and the second sub-transmission mechanism shifter 540 can be transmitted to the output shaft 960. Further, the second auxiliary transmission mechanism shifter 540 is engaged with the teeth of the seventh auxiliary transmission gear 514a, so that the rotational power of the main transmission output shaft 910 is supplied to the fifth auxiliary transmission gear 513a and the sixth auxiliary transmission gear. 513b, a sub-transmission transmission shaft 516, a second sub-transmission gear 511b, a creep mechanism 514b, a seventh sub-transmission gear 514a, and a second sub-transmission mechanism shifter 540 so as to be transmitted to the output shaft 960. It has become.

  By adopting such a configuration, the transmission 200 can perform sub-shifting by the speed change mechanisms 250 and 280 and the hydraulic clutch mechanisms 240 and 270. Here, the first to sixth shifts can be sub-shifted in four stages of first to third sub-shift stages and creep stages.

  Next, the transmission 200 of the second embodiment will be described with reference to FIG. However, members having the same reference numerals as those in the first embodiment shown in FIG. 7 have the same configuration in the second embodiment, and thus detailed description thereof is omitted.

  As shown in FIG. 7, the transmission 200 of the second embodiment includes an input shaft 210, a forward hydraulic clutch mechanism 410, a reverse hydraulic clutch mechanism 420, a reverse transmission shaft 290, a main clutch output shaft 291, The main transmission shaft 292, the first transmission mechanism 250, the first transmission shaft 230, the first hydraulic clutch mechanism 240, the second transmission mechanism 280, the second transmission shaft 260, and the second hydraulic clutch mechanism 270, The third transmission shaft 293 is provided.

  The rear portion of the input shaft 210 is connected to the PTO shaft 111, and the pipe-shaped third transmission shaft 293 and the sub-transmission transmission shaft 516 are loosely fitted on the rear portion of the input shaft 210 (or the PTO shaft 111). The main clutch output shaft 291, the main transmission shaft 292, the PTO shaft 111, the third transmission shaft 293, and the sub-transmission transmission shaft 516 are disposed on an extension of the same axis.

  In addition, a first transmission shaft 230 is disposed behind the reverse transmission shaft 290, and a pipe-shaped second transmission shaft 260 is loosely fitted on the front portion of the first transmission shaft 230. A pipe-like main transmission output shaft 910 is loosely fitted at the rear, an output shaft 960 is disposed behind the main transmission output shaft 910, a reverse transmission shaft 290, a first transmission shaft 230, and a second transmission shaft. 260, the main transmission output shaft 910, and the output shaft 960 are disposed on an extension of the same axis.

  Two sets of main transmissions are arranged between the main transmission shaft 292 and the first transmission shaft 230 and between the main transmission shaft 292 and the second transmission shaft 260, respectively. In addition, odd-numbered shift stages of the first speed and the third speed, and even-numbered shift stages of the second speed and the fourth speed are arranged on the second transmission shaft 260 in the front-rear direction. Specifically, a first transmission mechanism 250 with an odd gear stage is arranged at the front part on the first transmission shaft 230, and a second transmission mechanism 280 with an even gear stage is arranged at the front part on the second transmission shaft 260. .

  A first speed gear mechanism 251a and a third speed gear mechanism 251b are disposed between the first speed change mechanism 250 and the front part of the main speed change shaft 292, and between the second speed change mechanism 280 and the rear part of the main speed change shaft 292. In addition, a second speed gear mechanism 281a and a fourth speed gear mechanism 281b are provided.

  A pair of front and rear hydraulic clutches for main speed change are arranged on the third transmission shaft 293. The hydraulic clutch has a second hydraulic clutch mechanism 270 at the front, and a first hydraulic clutch mechanism 240 at the rear. Has been placed. Further, a first drive transmission mechanism 116 constituted by a gear mechanism is disposed between the first hydraulic clutch mechanism 240 and the rear portion of the first transmission shaft 230, and between the second hydraulic clutch mechanism 270 and the rear portion of the second transmission shaft 260. A second drive transmission mechanism 117 composed of a gear mechanism is disposed at the front, and a third drive transmission mechanism 930 composed of a gear mechanism is disposed between the rear portion of the third transmission shaft 293 and the front portion of the main transmission output shaft 910. Has been.

  Specifically, the first drive transmission mechanism 116 is integrally provided on the input side of the first hydraulic clutch mechanism 240, and the first transmission gear 116 a that is loosely fitted on the third transmission shaft 293 is replaced with the first transmission shaft 230. It is meshed with a first output gear 116b fixed on the top so that power can be transmitted. The second drive transmission mechanism 117 is integrally provided on the input side of the second hydraulic clutch mechanism 270, and the second transmission gear 117a is loosely fitted on the third transmission shaft 293 in front of the first transmission gear 116a. The second output gear 117b fixed on the second transmission shaft 260 is meshed with the power transmission. A first hydraulic clutch mechanism 240 is formed between the first transmission gear 116 a and the third transmission shaft 293, and a second hydraulic clutch mechanism 270 is formed between the second transmission gear 117 a and the third transmission shaft 293. The first hydraulic clutch mechanism 240 and the second hydraulic clutch mechanism 270 are integrally formed front and rear on a concentric shaft. The first transmission gear 116a and the second transmission gear 117a are disposed on both front and rear sides with the first hydraulic clutch mechanism 240 and the second hydraulic clutch mechanism 270 interposed therebetween. The third drive transmission mechanism 930 includes a third transmission gear 930a fixed at the rear portion on the third transmission shaft 293, and a third output gear 930b fixed at the front portion on the main transmission output shaft 910. It is meshed so that power can be transmitted.

  Thus, the first transmission path 200a is formed from the first transmission mechanism 250 to the first hydraulic clutch mechanism 240 via the first drive transmission mechanism 116, and from the second transmission mechanism 280 via the second drive transmission mechanism 117. Thus, a second transmission path 200b is formed up to the second hydraulic clutch mechanism 270. As described above, the transmission path from the main transmission shaft 292 to the main transmission output shaft 910 includes the first transmission path 200a and the second transmission path 200b, thereby forming a compact transmission with a simple transmission path configuration. It becomes possible.

  Further, in the first transmission mechanism 250 and the second transmission mechanism 280, an odd-numbered gear stage (or even gear stage) synchronous mesh type multi-speed transmission mechanism is disposed at the front portion on the first transmission shaft 230, and the second transmission shaft 260 is arranged. A synchronous meshing multi-stage transmission mechanism with an even-numbered gear stage (or an odd-numbered gear stage) is disposed at the upper front portion. In the present embodiment, a transmission mechanism (first transmission mechanism 250) for odd-numbered gears of the third speed and the first speed is arranged at the front, and a transmission mechanism for even-numbered gears of the second and fourth speeds (the first gear mechanism 250) is arranged at the rear. A second transmission mechanism 280) is disposed.

  Then, the third drive gear 263 and the first drive gear 261 are loosely fitted on the front portion on the first transmission shaft 230, and the first speed change mechanism shifter 252 is spline-fitted between them, and can slide in the axial direction. In addition, it is externally fitted so as not to be relatively rotatable, and can be selected as the third speed or the first speed by sliding forward or backward by operation of the speed change operation means. In addition, the second drive gear 262 and the fourth drive gear 264 are loosely fitted to the front portion on the second transmission shaft 260, and the second speed change mechanism shifter 282 is spline fitted between them, and can slide in the axial direction. In addition, it is externally fitted so as not to be relatively rotatable, and can be selected as the second speed or the fourth speed by sliding forward or backward by operating the speed change operation means.

  The first and second hydraulic clutch mechanisms 240 and 270 are configured to selectively transmit the rotational power of the first transmission shaft 230 or the second transmission shaft 260 to the third transmission shaft 293. In this embodiment, the first hydraulic clutch mechanism 240 connects / disconnects odd-numbered gears, and the second hydraulic clutch mechanism 270 connects / disconnects even-numbered gears. Alternatively, an odd number of gears may be connected / disconnected by the second and second hydraulic clutch mechanisms 270. In this way, it is possible to connect and disconnect the two sets of main transmissions on the two shaft centers, thereby forming a compact transmission.

  The control device 600 responds to a first external operation (operation of the main transmission lever 110) with respect to the transmission mechanism (250 or 280) in one transmission path (200a or 200b) of the first transmission path 200a and the second transmission path 200b. And a hydraulic clutch mechanism (200a or 200b) in one transmission path (200a or 200b), and the transmission mechanism (280 or 250) in the other transmission path (200b or 200a) is disengaged. 240 or 270) is in a power transmission state, and the hydraulic clutch mechanism (270 or 240) in the other transmission path (200b or 200a) is in a power cut-off state, and then the next second external operation (main shift lever 110 operation). Is made, the transmission mechanism (200a or 200b) in one transmission path ( 50 or 280) is kept engaged with the gear position corresponding to the first external operation, and the speed change mechanism (280 or 250) in the other transmission path (200b or 200a) is shifted according to the second external operation. While the stage is engaged, the hydraulic clutch mechanism (240 or 270) in one transmission path (200a or 200b) is gradually shifted from the power transmission state to the power cutoff state, and at the same time the other transmission path (200b or 200a). The hydraulic clutch mechanism (270 or 240) in (1) is gradually shifted from the power cut-off state to the power transmission state.

  Next, a specific example of the speed change operation will be described. In the state where the forward hydraulic clutch mechanism 410 or the reverse hydraulic clutch mechanism 420 is in the “contact” state, first, when the main transmission lever 110 is shifted from the neutral position N to the first speed, the electromagnetic valve 622 is switched, By actuating the actuator 630, the first speed change mechanism shifter 252 is slid and meshed with the teeth of the first driven gear 230a in the first speed gear mechanism 251a, and the first driven gear 261 to the first driven gear. Power can be transmitted to the first transmission shaft 230 via 230a. At the same time, the electromagnetic valve 620 is switched so that the first hydraulic clutch mechanism 240 is “contacted”, and power is transmitted from the main transmission shaft 292 to the third transmission shaft 293 via the first transmission path 200a. . Specifically, power is transmitted from the main transmission shaft 292 to the first drive gear 261, the first driven gear 230 a, the first transmission shifter 252, the first transmission shaft 230, and the first hydraulic clutch mechanism 240, and the power is transmitted to the third transmission shaft 293. Is transmitted. Power is transmitted from the third transmission shaft 293 to the rear wheels (drive wheels) 102 and 102 via the third drive transmission mechanism 930, the main transmission output shaft 910, the auxiliary transmission mechanism 500, and the differential device 900. On the other hand, since the second hydraulic clutch mechanism 270 is “disconnected” in the second transmission path 200b, the rotational power from the main transmission shaft 292 to the third transmission shaft 293 is not transmitted.

  Next, when the main transmission lever 110 is shifted from the first speed to the second speed, the electromagnetic valve 623 is switched, the actuator 631 is operated, and the second shift mechanism shifter 282 is slid to move the second driven gear. Engaged with the tooth portion of 260a, power can be transmitted from the second driven gear 260a to the second transmission shaft 260. At the same time, the operating voltage to the electromagnetic valve 620 is gradually decreased, the operating voltage to the electromagnetic valve 621 is gradually increased, and the operating hydraulic pressure fed to the first hydraulic clutch mechanism 240 as shown in FIG. α is gradually decreased, and the hydraulic pressure β fed to the second hydraulic clutch mechanism 270 is gradually increased. For example, in the first speed shift state (see γ1), the first hydraulic clutch mechanism 240 is “contact” and the second hydraulic clutch mechanism 270 is “disconnected”. In the transition period when shifting from the first speed to the second speed (see γ2), the hydraulic pressure to the first hydraulic clutch mechanism 240 decreases and the hydraulic pressure to the second hydraulic clutch mechanism 270 increases. The first hydraulic clutch mechanism 240 and the second hydraulic clutch mechanism 270 are both “contacted” while sliding, and are in a so-called half-clutch state, and power is transmitted to the first transmission path 200a and the second transmission path 200b. .

  Then, in a state where the predetermined time has elapsed and the gear is completely shifted to the second speed (see γ3), the supply of hydraulic oil to the first hydraulic clutch mechanism 240 is stopped and becomes “OFF”, and the second hydraulic clutch The working oil pressure to the mechanism 270 becomes the set oil pressure and becomes “contact”. Then, power is not transmitted to the first transmission path 200a, but power is transmitted to the second transmission path 200b. Specifically, the power is transmitted from the main transmission shaft 292 to the second drive gear 262, the second driven gear 260 a, the second transmission shifter 282, the second transmission shaft 260, and the second hydraulic clutch mechanism 270 to provide power to the third transmission shaft 293. Is transmitted. At the same time, the electromagnetic valve 622 is switched to operate the actuator 630, and the first shift mechanism shifter 252 is slid to the neutral side.

  Further, when the main speed change lever 110 is changed from the second speed to the third speed, the electromagnetic valve 622 is switched, the actuator 630 is operated, and the first speed change mechanism shifter 252 is slid, and the third speed gear. The gear is engaged with the tooth portion of the third driven gear 230b in the mechanism 251b, power is transmitted from the third driven gear 230b to the first transmission shaft 230, and the operating hydraulic pressure to the second hydraulic clutch mechanism 270 is decreased, The electromagnetic valves 621 and 620 are switched so as to increase the operating hydraulic pressure to the first hydraulic clutch mechanism 240. Thus, as described above, the half-clutch state is revealed, and power is transmitted to the first transmission path 200a and the second transmission path 200b.

  Then, in a state where the predetermined time has elapsed and the gear has been completely shifted to the third speed (see γ3), the supply of hydraulic oil to the second hydraulic clutch mechanism 270 is stopped and becomes “disconnected”, and the first hydraulic clutch The working hydraulic pressure to the mechanism 240 becomes the set hydraulic pressure and becomes “contact”. Then, power is not transmitted to the second transmission path 200b, but power is transmitted to the first transmission path 200a. Specifically, power is transmitted from the main transmission shaft 292 to the third drive gear 263, the third driven gear 230 b, the first transmission shifter 252, the first transmission shaft 230, and the first hydraulic clutch mechanism 240, and the motive power is transmitted to the third transmission shaft 293. Is transmitted. At the same time, the electromagnetic valve 623 is switched to operate the actuator 631, and the second shift mechanism shifter 282 is slid to the neutral side.

  When shifting to the fourth speed change, in the second transmission path 200b, the main transmission shaft 292 to the fourth drive gear 264, the fourth driven gear 260b, the second speed change shifter 282, the second transmission shaft 260, A transmission path for the fourth shift is formed which is transmitted to the second hydraulic clutch mechanism 270 and passes through the third transmission shaft 293.

  A specific example of the shift operation from the first shift to the third shift will be described. As described above, in the state of being shifted to the first speed change, the first speed change mechanism shifter 252 is engaged with the tooth portion of the first driven gear 230a in the first speed gear mechanism 251a, and the first drive gear 261 starts the first shift. Power can be transmitted to the first transmission shaft 230 via the first driven gear 230a, the first hydraulic clutch mechanism 240 is "contacted", and the second hydraulic clutch mechanism 270 is "disconnected". Specifically, the first transmission gear 261, the first driven gear 230 a, the first transmission shifter 252, the first transmission shaft 230, and the first hydraulic clutch mechanism 240 are transmitted from the main transmission shaft 292 and pass through the third transmission shaft 293. A transmission path for the first speed change is formed.

  When the main transmission lever 110 is shifted from the first speed to the third speed, the first hydraulic clutch mechanism 240 continues to be “contacted” and the second hydraulic clutch mechanism 270 remains “disconnected”. The forward hydraulic clutch mechanism 410 (or the reverse hydraulic clutch mechanism 420), which is in “contact”, is “disconnected”. At the same time, the electromagnetic valve 622 is switched, the actuator 630 is operated, the first speed change mechanism shifter 252 is slid, and is meshed with the tooth portion of the third driven gear 230b in the third speed gear mechanism 251b. Thus, the power can be transmitted from the third driven gear 230b to the first transmission shaft 230, and the forward hydraulic clutch mechanism 410 (or the reverse hydraulic clutch mechanism 420) that has been “disconnected” is brought into “contact” again. The In this manner, the third transmission shaft 293 is transmitted from the main transmission shaft 292 to the third drive gear 263, the third driven gear 230b, the first transmission shifter 252, the first transmission shaft 230, and the first hydraulic clutch mechanism 240. A transmission path for the third speed change passing through is formed.

  Note that when the main transmission lever 110 is shifted from the second speed to the fourth speed, the second hydraulic clutch mechanism 270 continues to be “connected” and the first hydraulic clutch mechanism 240 remains “disconnected”. The forward hydraulic clutch mechanism 410 (or the reverse hydraulic clutch mechanism 420), which is in “contact”, is “disconnected”. At the same time, the electromagnetic valve 623 is switched, the actuator 631 is operated, the second speed change mechanism shifter 282 is slid, and meshed with the teeth of the fourth driven gear 260b in the fourth speed gear mechanism 281b. Thus, power can be transmitted from the fourth driven gear 260b to the second transmission shaft 260, and the forward hydraulic clutch mechanism 410 (or the reverse hydraulic clutch mechanism 420) that has been “disconnected” is again brought into “contact”. The In this way, the transmission path of the second speed change is changed to the transmission path of the fourth speed change.

  As described above, the transmission 200 is a transmission 200 in which power is transmitted from the drive source 105 to the rear wheels (drive wheels) 102 and 102, and the input shaft 210 is operatively connected to the drive source 105. A main clutch output shaft 291 disposed parallel to the input shaft 210, and a pair of forward and reverse hydraulic clutches disposed on the input shaft 210 and switching the rotational direction of power transmitted to the main clutch output shaft 291 Mechanisms 410, 420; two sets of gear-synchronized first and second transmission mechanisms 250, 280 disposed on the output side of the pair of forward and reverse hydraulic clutch mechanisms 410, 420; Power that is disposed on the output side of the first and second transmission mechanisms 250 and 280 and is transmitted from each of the two sets of first and second transmission mechanisms 250 and 280 A pair of first and second hydraulic clutch mechanisms 240, 270 that switch connection / disconnection, and one odd gear shift stage by the two sets of first and second transmission mechanisms 250, 280 to another odd gear shift stage, or one In the shifting operation from the even gear to another even gear, the pair of forward and reverse hydraulic clutch mechanisms 410 and 420 are interlocked with the reverser lever 114 and the clutch pedal 123 to form a main clutch. Is. By adopting such a configuration, the forward / reverse switching and the main shift switching can be switched with no clutch without having to provide a hydraulic clutch at each shift stage as in the conventional hydraulic clutch transmission, so a separate main clutch The forward and reverse hydraulic clutch mechanisms 410 and 420, and the first and second hydraulic clutch mechanisms 240 and 270 can be configured inexpensively and compactly, and the first and second hydraulic clutch mechanisms 240 and 270 By disposing on the output side of the first and second transmission mechanisms 250 and 280, the load on the first and second hydraulic clutch mechanisms 240 and 270 is reduced, and the first and second hydraulic clutch mechanisms 240 and 270 are made smaller. As a result, the transmission case 109 can be made compact and the transmission 200 can be made compact at low cost. Kill.

The side view which shows the traveling vehicle to which the transmission which concerns on this Embodiment is applied. The skeleton figure of the transmission which concerns on a 1st Example. The figure which shows the time change of the working hydraulic pressure supplied to a 1st hydraulic clutch mechanism and a 2nd hydraulic clutch mechanism from a hydraulic mechanism in the case of gear shifting operation. The top view of a main gearshift lever. The top view which shows a reverser lever. The figure which shows the operating system of a reverser lever, a main transmission lever, a clutch pedal, the 1st and 2nd hydraulic clutch mechanism, the shifter for 1st and 2nd transmission mechanisms, and the forward and backward hydraulic clutch mechanism. The skeleton figure of the transmission which concerns on a 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 102 Drive wheel 105 Drive source 114 Reverser lever 123 Clutch pedal 200 Transmission 210 Input shaft 240 1st hydraulic clutch mechanism 250 1st speed change mechanism 270 2nd hydraulic clutch mechanism 280 2nd speed change mechanism 291 Main clutch output shaft 410 Advance hydraulic clutch mechanism 420 Reverse hydraulic clutch mechanism

Claims (1)

A transmission in which power is shifted and transmitted from a drive source to drive wheels,
An input shaft operatively connected to the drive source;
A transmission shaft arranged parallel to the input shaft;
A pair of reverser clutches arranged on the input shaft and for switching the rotational direction of the power transmitted to the transmission shaft;
Two sets of gear-synchronized main transmissions arranged on the output side of the pair of reverser clutches;
A pair of clutches that are arranged on the output side of the two sets of main transmissions and that switch between connection and disconnection of power transmitted from each of the two sets of main transmissions;
In the shifting operation from one odd gear to another odd gear, or from one even gear to another even gear by the two sets of main transmissions, the pair of reverser clutches includes a reverser lever and a clutch pedal. A transmission characterized by being linked to the main clutch.

Images