JPH0121233Y2 - - Google Patents

Description

[Detailed explanation of the idea]

In the present invention, an input shaft, a first intermediate shaft, and a second intermediate shaft are arranged concentrically, and a reverse cylinder shaft is provided on the first intermediate shaft, and an output cylinder shaft is rotated relative to the second intermediate shaft. A first hydraulic clutch is mounted between the input shaft and the first intermediate shaft, and a fluid pressure operated first clutch is connected between the input shaft and the reverse cylinder shaft. A fluid pressure operated second clutch is provided between the clutches, and a fluid pressure operated third clutch is provided between the second intermediate shaft and the output cylindrical shaft, and is fixed to the first and second intermediate shafts respectively. third and fourth external gears that are always in mesh with the first and second external gears, respectively, are attached to the spider so as to be relatively rotatable, and fifth and sixth external gears are respectively fixed to the two cylindrical shafts. Seventh and eighth external gears that engage with the third and fourth external gears respectively are attached to the spider so as to be relatively rotatable, and a fluid pressure operated first a brake, a fluid-pressure-operated second brake for an internal gear that is always engaged with the third external gear, and a fluid-pressure-operated third brake for the second intermediate shaft, and the first clutch is operated in a forward movement state. The second and third clutches and the first to third brakes are selectively operated while the clutches are in the engaged state, and the second clutch is maintained in the engaged state and the third clutch and the second brake are selectively operated in the reverse state. ,
The present invention relates to a hydraulically operated travel transmission equipped with a valve mechanism for selectively operating a third brake. Conventionally, in such a traveling transmission, a valve mechanism for speed change operation is provided with just one control valve, but in this case, the control is performed by a speed change lever that reciprocates in one direction. Due to the fact that a spool that can be reciprocated in one direction in the valve is operated, there is a disadvantage that it is difficult to perform a speed change operation, and there is also a disadvantage that it is easy to operate erroneously, so there is room for improvement. To be more specific, in the case of a shift lever, it is desirable to increase the distance between adjacent shift positions so that each shift position can be easily identified, but in the case of the above conventional structure, the distance between adjacent shift positions is If it is set too high, the operating range of the gear shift lever becomes large, which has the disadvantage that the operator has to operate the gear shift lever while extending his/her hand.To avoid this, it is recommended to reduce the distance between adjacent gear shift positions. However, the shift position was difficult to determine, leading to erroneous operation. The present invention has been developed in view of the above-mentioned circumstances, and its purpose is to improve operability through simple modification that effectively utilizes the original configuration. A characteristic configuration of the fluid pressure operated travel transmission according to the present invention is that the valve mechanism includes a first control valve for switching forward and backward travel that selectively supplies fluid pressure to the first and second clutches; , a second speed setting control valve for selectively supplying fluid pressure to the second and third clutches and the first to third brakes;
The first and second control valves are connected in parallel to the second clutch via a shuttle valve, and different two control valves are connected in parallel to the second clutch via a shuttle valve.
A single gear shift lever that can be freely operated in one direction is linked to both control valves so that operation in one direction operates the first control valve and operation in the other direction operates the second control valve. , its functions and effects are as follows. That is, focusing on the fact that the first clutch is maintained in the engaged state in the forward traveling state and the second clutch is maintained in the engaged state in the reverse traveling state, the first control valve for forward/reverse switching and the second control valve for speed setting are controlled. are provided separately for each, and the fluid supplied to the second clutch, which is engaged in both forward and backward motion, is
In order to prevent oil from being drained through the first control valve in the forward drive state and to prevent oil from being drained through the second control valve in the reverse drive state, the second clutch is controlled by the first and second control valves using a shuttle valve. By connecting it to the valve, it is possible to perform a predetermined speed change by operating the first and second control valves, and furthermore, it is possible to operate two control valves while operating one shift lever in two different directions. It is set as. Therefore, while taking advantage of the advantage of shifting with a single gear lever, the operation stroke of the gear lever in each of the two different directions is minimized.
The distance between adjacent shift positions in each direction can be made sufficiently large, so that the shift lever can be operated satisfactorily while performing multi-stage shifting. Next, embodiments of the present invention will be described in detail based on illustrative drawings. As shown in FIG. 1, a front vehicle body 2 equipped with a pair of left and right front wheels 1 and a rear vehicle body 4 equipped with a pair of left and right rear wheels 3 are connected so as to be relatively swingable around a vertical axis P. The front body 2 is equipped with a front loader 5 that can be freely raised and lowered, and the rear body 4 is equipped with a boarding section 6, a driving section 7, and a backhoe device 8. The steering handle 6 is controlled by the hydraulic cylinder 9 installed over the
The structure is configured to relatively drive and sway both the front and rear vehicle bodies 2 and 4 by an amount corresponding to the amount of operation a, and perform vehicle direction. The earthmoving vehicle is configured to transmit the variable speed power to the front wheels 1 and the rear wheels 3, respectively, and thereby performs earth-moving work and excavation work. To configure the transmission structure in the traveling transmission case 11, as shown in FIGS. 2 and 3, the input shaft 12, the first intermediate shaft 13, and the second intermediate shaft 14 are arranged concentrically. and the first intermediate shaft 13
The reverse cylindrical shaft 15 is attached to the second intermediate shaft 14, and the output cylindrical shaft 16 is attached to the second intermediate shaft 14 so as to be relatively rotatable. A multi-plate first transmission clutch 18 is mounted between the input shaft 12 and the first intermediate shaft 13, and a multi-plate second transmission clutch is mounted between the input shaft 12 and the reverse cylinder shaft 15. clutch 19
and a third transmission clutch 20 is provided between the second intermediate shaft 14 and the output cylinder shaft 16, and first and second transmission clutches are respectively attached to the first and second intermediate shafts 13 and 14.
The third and fourth gears G ₃ and G ₄ , which are always engaged with the gears G ₁ and G ₂ respectively, are attached to the spider 17 so as to be relatively rotatable, and the fifth gears are attached respectively to the double cylinder shafts 15 and 16, respectively.
The 6th gear G ₅ and G ₆ are engaged separately, and the 3rd gear
The 7th and 8th gears G 7 and G ₈ that engage with the 4th gears G _{3 and} G ₄ separately are attached to the spider 17 so as to be relatively rotatable, and the multi-plate type is used to fix the reverse cylinder shaft 15 to the case 11. A first brake 21, a multi-plate second brake 22 for fixing to the case 11 the internal gear GF that is always engaged with the third gear _G3 , and a multi-plate second brake 22 for fixing the second intermediate shaft 14 to the case 11. Plate type 3
A brake 23 is provided, and the input shaft 12 is interlocked and connected to the engine 10 via a travel clutch 24 and a gear interlocking mechanism, and the output cylinder shaft 16 is connected to the output shaft for the front and rear wheels 1 and 3 via the gear interlocking mechanism. 25 is interlocked and connected. A hydraulic cylinder section 18 for clutch operation is attached to each transmission clutch 18 to 23 in a state where it is always biased toward the transmission disengaged state.
A valve mechanism is provided to selectively supply pressure oil from the hydraulic pump 26 to a to 23a, and a five-stage forward speed is provided.
It is configured to be switchable between F ₁ to _{F 5} , two reverse gears R ₁ and R ₂ , and a neutral shift state N. More specifically, in the forward state, the first
The clutch 18 is maintained in the engaged state and the second and third
The clutches 19, 20 and the first to third brakes 21, 22, 23 are selectively operated, and in the reverse driving state, the second clutch 19 is maintained in the engaged state and the third clutch 20 and the second and third brakes are operated. 22 and 23 will be selected. and,
The following table shows the pressure oil supply state in each gear shift state. However, (〇) indicates pressure oil supply and
(x) indicates drained oil.

[Table] As shown in FIGS. 3 and 4, the valve mechanism includes a first control valve for forward/reverse switching that selectively supplies fluid pressure to the first and second clutches 18, 19. V ₁ and the second and third clutches 19, 20
and a second control valve V ₂ for speed setting that selectively supplies fluid pressure to the first to third brakes 21, 22, 23, and the first and second control valves V ₁ and V ₂ are configured as shuttle valves. 27 to the second clutch 19 in parallel. In order to operate the first and second control valves V ₁ and V ₂ , one shift lever 28 is supported on a ball fulcrum Z so as to be swingable in the longitudinal direction and in the left and right directions. ) An elongated lever insertion hole 30 along the front-rear direction is formed in the arm 29 that operates the first control valve V ₁ by swinging around the horizontal axis (Y). Arm 3 that operates the second control valve V ₂
1, a long lever insertion hole 32 along the left and right direction.
Furthermore, a lever guide frame 34 having a lever insertion groove 33 is provided, and the shift lever 2
It is constructed so that the gear can be changed by the rocking operation of 8. To carry out the present invention, the gear shift lever 28 is supported so as to be movable in the longitudinal direction and in the lever axis direction,
Then, by moving the lever in the axial direction, the first control valve V ₁
and a support structure for the shift lever 28, such as allowing the second control valve _V2 to be operated by moving in the front-rear direction, and the shift lever 28 and the first and second control valves.
The linkage structure with V ₁ and V ₂ can be changed in various ways. In addition, the traveling transmission device of this proposal can be used not only for construction work vehicles, but also for
It can be applied to various work vehicles such as agricultural work vehicles.

[Brief explanation of the drawing]

The drawings show an embodiment of the hydraulically operated traveling transmission device according to the present invention, and FIG. 1 is a side view of an earthmoving vehicle, and FIG.
FIG. 3 is a schematic diagram of the traveling transmission, FIG. 3 is a hydraulic circuit diagram, and FIG. 4 is a perspective view showing a valve operation configuration. 12...Input shaft, 13...First intermediate shaft, 14...
... Second intermediate shaft, 15 ... Reverse cylinder shaft, 16 ... Output cylinder shaft, 17 ... Spider, 18 ... First clutch, 19 ... Second clutch, 21 ... First brake, 22 ... ...Second brake, 23...Third brake, 27...Shuttle valve, 28...Speed lever, _{G1 to G8 ...} External gear, GF...Internal gear, _V1 ...First control valve , V ₂ ... second control valve.

Claims (1)

[Scope of utility model registration request] Input shaft 12, first intermediate shaft 13, and second intermediate shaft 1
4 are arranged concentrically, a reverse cylinder shaft 15 is attached to the first intermediate shaft 13, and an output cylinder shaft 16 is attached to the second intermediate shaft 14 so as to be relatively rotatable, and both ends of the spider 17 are connected to the two ends of the spider 17. A fluid pressure operated first clutch 18 is mounted on the cylindrical shafts 15 and 16 separately and relatively rotatably, and between the input shaft 12 and the first intermediate shaft 13.
A fluid pressure operated second clutch 19 is provided between the input shaft 12 and the reverse cylinder shaft 15, and a fluid pressure operated third clutch 20 is provided between the second intermediate shaft 14 and the output cylinder shaft 16. are provided, respectively, and are fixed to the first and second intermediate shafts 13 and 14, respectively.
The third and fourth external gears G ₃ and G ₄ , which are always engaged with the external gears G ₁ and G ₂ separately, are attached to the spider 17.
The two cylinder shafts 15, 16 are mounted so as to be relatively rotatable.
The fifth and sixth external gears _G5 and
Seventh and eighth gears that engage G ₆ separately and engage the third and fourth external gears G ₃ and G ₄ , respectively.
External gears G ₇ and G ₈ are attached to the spider 17 so as to be relatively rotatable, and a fluid pressure operated first brake 21 for the reverse cylindrical shaft 15 and an internal gear GF constantly meshed with the third external gear 29. A fluid pressure operated second brake 22 is provided for the second intermediate shaft 14, and a fluid pressure operated third brake 23 is provided for the second intermediate shaft 14 to maintain the first clutch 18 in the engaged state in the forward movement state. 3 clutch 1
9, 20 and the first to third brakes 21,
A valve mechanism is provided for selectively operating the third clutch 20 and the second and third brakes 22 and 23 by selectively operating the third clutch 22 and 23, and maintaining the second clutch 19 in the engaged state in the reverse traveling state. In the hydraulically operated traveling transmission, the valve mechanism includes the first and second clutches 18 and 19.
a first control valve V ₁ for forward/reverse switching that selectively supplies fluid pressure to
20 and the first to third brakes 21, 2
A second speed setting control valve V ₂ is provided to selectively supply fluid pressure to the first and second control valves V ₁ , 23 .
V ₂ is connected in parallel to the second clutch 19 via the shuttle valve 27, and one shift lever 28 that can be operated in two different directions is operated in one direction to control the first control valve V ₁ and , a hydraulically operated travel transmission connected to both control valves V ₁ and V ₂ so as to operate the second control valve V ₂ by operation in the other direction.