JPS6069352A - Speed change gear for running work vehicle - Google Patents

Abstract

PURPOSE:To simplify a subgear speed change device, by providing two low speed side transmission parts of different speed change ratio in the subgear speed change device while a clutch mechanism which switches a condition of use of the low speed side transmission parts. CONSTITUTION:A clutch sleeve 23, being alternatively engaged with the second cylindrical shaft 19 or a two-stage gear 22 following the operation by a hydraulic cylinder 12 for controlling a speed change shifter, is mounted to be externally fitted by a spline to the third transmission shaft 18. Then a movable clutch piece 25a, being alternatively engaged with two low speed side transmission gears 21a, 21b following the sliding operation by a manual control lever 24, is externally fitted by a apline to the first cylindrical shaft 17, forming a clutch mechanism. In this way, a speed change gear of variable speed in multiple stages can be obtained by simplifying its construction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a traveling transmission for a work vehicle, which is provided with a main gear transmission and an auxiliary gear transmission arrangement that changes gears in two stages, high and low.

Such a traveling transmission is capable of multi-speed shifting by combining a main gear transmission and an auxiliary gear transmission, but in high-speed situations where the auxiliary gear transmission is switched to the commercial side, it is possible to perform further gear changes. It is desirable to be able to perform multi-stage shifting with small speed differences, and to run the vehicle at as high a speed as possible while suppressing overload on the engine.

In other words, when working with a book connected to a tractor, for example, it is necessary to perform multi-stage shifting with small speed differences in order to improve work efficiency and avoid overloading the engine.

For this reason, the inventor considered a means to provide a number of auxiliary gears that change gears in two high and low gears separately from the auxiliary gear transmission system, but in this case, the entire auxiliary gear transmission system It was difficult to put into practical use because absorption was complicated and the disadvantage was too high.

The present invention was created in view of the above-mentioned actual situation, and its purpose is to have a simple structure that utilizes absorption in its original form.
The purpose is to enable multi-speed shifting at high speeds.

The characteristic configuration of the traveling transmission for a working vehicle according to the present invention is that the auxiliary gear transmission is provided with two low-speed transmission sections with different gear ratios, and the use state of the low-speed transmission sections is switched. The advantage is that a clutch mechanism is provided, and its effects are as follows.

That is, if one of the two low-speed transmission parts is used, the traveling speed can be changed in multiple stages over a wide range, and contrary to n, if one low-speed transmission part J is used,
If the high-speed side of the parts is used, the traveling speed can be changed in multiple stages within a small range on the high-speed side. In order to achieve all of these, the configuration is such that the auxiliary gear transmission has seven high-speed transmission sections and one low-speed transmission section with different gear ratios. Compared to providing the above-mentioned auxiliary auxiliary gear transmission which is configured with two high and low transmission parts separately from the auxiliary gear transmission, a simple S configuration with fewer transmissions G16 is provided. I can do it.

Therefore, it is possible to carry out multi-stage shifting in high-speed situations by taking advantage of the practical aspects of manufacturing, thereby obtaining a traveling transmission device for work vehicles that can be used more conveniently. reached.

Hereinafter, uninvented embodiments will be described based on the drawings.

Figure 1 shows the transmission structure in one transmission case equipped with a tractor VC. Flexible synchronized main gear transmission f
ftff (H+) is provided, and a friction plate type transmission clutch (Ol
a synchromesh type forward/reverse gear transmission m (112) which changes the output of the second transmission shaft (3) in forward and reverse directions;
A synchronized mesh type first auxiliary gear that can freely switch the output from high to low in one step [H3], and.

No. 2, which can be freely switched to a hook that greatly decelerates the output from the
Auxiliary gear transmission B (H+') is provided, and @
The output of the two auxiliary gear transmission @CH,) is configured to be transmitted to the differential mechanism (4A) of the @wheel (4) and the differential mechanism (5A) of the front wheel (5).

A synchronized mesh gear transmission (7) that shifts the power of the input shaft (1) to the V stage and transmits it to the power output transmission shaft (61) is installed, and a transmission shaft (61 and A friction plate type transmission clutch (9) is provided between the power take-off shaft (δ1), so that the power take-off shaft (8) can be changed in speed.

Next, the speed change operation structure for the driving transmission system will be described in detail with reference to FIGS. 1 and 2.

That is, the 2Il of the hydraulic cylinder (10) for operating the gear shifter which is alternatively operated in the main gear transmission &(H,).
! In addition to installing IL, forward and backward gear transmission (H7)
and the first auxiliary gear transmission @ (H3) are provided with seven hydraulic cylinders till and α2 for operating the transmission shifter, and a hydraulic cylinder θ3 for operating the transmission shifter clutch (0) K%. ) Fully equipped.

The main gear shifting hydraulic cylinder FIO), +101
and a main control valve (vl) for each of the first auxiliary transmission hydraulic cylinders a21, and an auxiliary control valve (vg) for the forward/reverse transmission hydraulic cylinder +Il+ (ts hydraulic pump Φ). Then, a 3-position switching valve (Sl) m (52)-(
An oil path that supplies pressurized oil from a switching valve (S,) configured with seven hydraulic cylinders (S, ), (54) and a hydraulic cylinder (11) for forward/reverse transmission to a hydraulic cylinder a9 for clutch operation. α41'ft is provided, and pilot pressure-operated switching valves (T1), (T2), (
A switching valve (S) is constructed by arranging three hydraulic cylinders (T, ) in series, and consisting of the main gear shifting hydraulic cylinders +101, [01 and the first sub-shifting hydraulic cylinder Q21, respectively.
Operated with pressure oil from ρ, (S, ) and (δ2) n
The clutch operation cylinder (13
Valve (51) * (TI) e (
T2) I (T3 piece, main gear transmission (Hl), forward/reverse gear transmission (H2), and first auxiliary gear transmission (
41S), so that the switching operation is automatically performed in conjunction with the gear shifting operation so that the switching operation is performed only in the transmission state of 41S).

However, the main gear transmission R (Hρ's two hydraulic cylinders QO
When one of I and [01 is operated to the t-shift side, the other hydraulic cylinder +101' is operated and held at the neutral shift position by pressure oil.
Further, the second auxiliary gear transmission (H4) is equipped with a shifter that can be freely operated with a speed change lever.

Furthermore, a transmission (7) and a transmission clutch (91) for the power take-off shaft (8) are configured to perform hydraulic sweeping in the same manner as the above-mentioned traveling transmission structure.

Main and auxiliary control valves Cvs ) * Cvs ) and clutch actuation control valves (51) l(TθI(Tρ, (T,
) is attached to the main relief pulp rJω on the upper side of the flow path, and the drained oil from the main relief pulp rJω is supplied to the transmission clutch (C) for lubrication.

The first auxiliary gear transmission (H3) is configured.

The clutch sleeve 061 in the forward/reverse gear transmission (H2) engages the first cylindrical shaft α71 with the forward center and the second cylindrical shaft α71.
A second cylindrical shaft Q9]K which is freely rotatably supported on the transmission shaft ('A) and freely rotatably supported on the third transmission shaft 081 parallel to the second transmission shaft (3),
The gear (19a) that is always in mesh with the gear (17a) attached to the first tsumugi αη, and the gear (lob) that is always in mesh with the reverse gear (sha) in the forward/reverse gear transmission (horse) are rotated integrally. The first cylindrical shaft αη is provided with a gear portion that freely rotatably supports two large and small low-speed transmission gears (21g) and (21b) and meshes with these gears (glb) and (2xb) separately. fc, 2nd gear (22), 2nd gear (23+ i, 8th transmission 1.H0)
Attach the spline outer shell to the spline (21a
).

A movable clutch piece (25a) that selectively engages with (21b)
) is externally fitted with a spline to the first cylinder shaft αη to constitute a clutch mechanism (2 (to)), thereby transmitting U7 from the first forward/reverse gear transmission (H2) to the second cylinder shaft (10). The high-speed state is output by the high-speed side transmission section fil VC, which transmits the power to the eighth transmission shaft (H8) without changing the speed, and the first forward/reverse gear transmission (transmitted from the H to the first cylinder shaft (17+). One low-speed transmission part (Ga) with a different speed ratio that reduces and transmits the power of the first power to the third transmission #Jaa using either the large-diameter low-speed transmission gear (21a) or the small-diameter transmission gear (glb).
.

(It is configured to switch to a low-speed state that applies pressure by cbyK-.)

Therefore, as shown in the graph shown in Fig. 4, the one on the low speed side (G
If you switch to the first state that uses b), the traveling speed (
2)) can be shifted to two speeds over a wide range, and can also be switched to the second state used for the high speed transmission part (Ga) 1 of the two low speed transmission parts (Ga) * (Gb). If this is done, the traveling speed can be shifted to two speeds in the high speed range. In other words, in the first condition above, the main tlilJ goben (VL)
If the main control valve (V,) is switched to the operating position (Fl to CF@) n, the speed can be changed over a wide range, and in the second state, the main control valve (V,) is switched to (H5) to (p*).
If n, the speed can be changed to the speeds indicated by (f, ) to (H4) in the graph.

As shown in FIGS. 2 and 3, a switching valve (S,
) is supplied through the high-speed side transmission oil passage (Uh).
A solenoid valve (Va) which can be suddenly switched is provided to supply pressure oil to the low speed side transmission oil passage (Ut), and an operation lever (2) for the clutch button Iυ is installed in the operation circuit for the solenoid valve (H3).
4) A manual switch installed in the control section of the tractor, where the limit switch is operated to suppress when it is operated to the low speed side.
, and a diaphragm pressure switch ρ which detects the supply of pressure oil to the high-speed transmission part 1i8 (Uh) are installed in series, thereby controlling the main $ control valve (V) from J series (H5) to ! When the clutch mechanism (24) is operated to the high speed side and the clutch mechanism (24) is operated to the high speed side, when the manual switch is turned on and the manual switch is operated (9), one low speed side transmission part (Ga) is activated. ,
(Gb) so that it can be operated on the transmission center using the one on the high speed side, and the pressure switch ρ~ is set to the main control valve (Vl) t''/speed (Fl) to gspeed (H4). This is to prevent unexpected high-speed conditions from being brought about by the action of blocking the energization of the solenoid valve (va) when any of the solenoid valves (va) are operated.

Therefore, when working with all the books connected, the clutch mechanism must be operated to the high speed side and the main control valve (
V□〕tJ speed CF, )～! Speed CF8) to determine the running speed, and if you turn on the manual switch □□□ at that time, the speed will be reduced by 9%, for example, compared to when you do not turn it on. A speed decelerated by a set rate of n is obtained.

In addition to being applied to tractors, the present invention can be applied to various work vehicles such as combines.
Various changes can be made depending on the intended use.

The present invention also provides a transmission shifter operation cylinder (101,
+IQ+, α or when shifting by operating a single friction plate clutch for shifting with a hydraulic cylinder, although not illustrated, it is possible to perform multi-stage shifting while simplifying the hydraulic structure. Although this is more convenient, it can also be applied to the case where each of the main gear transmission (Hl) and the auxiliary gear transmission 5t (HK) is manually operated. And even when operating using hydraulic pressure as described above,
Its operating structure can be changed in various configurations. For example, in the case of the embodiment, the main mlJ control valve (V□) is also configured to be operated by an electric drive device, and 7. ? The main Ifa valve (V□) and the solenoid valve (V□) may be automatically operated based on a command signal from an operation unit that selects a stage.

[Brief explanation of the drawing]

The drawings show an embodiment of a traveling transmission device for a working vehicle according to the invention, and Fig. 1 shows a transmission structure. Fig. 2 shows a hydraulic circuit diagram, Fig. 3 shows an electrical circuit diagram, and Fig. Figure Fi is a graph showing the relationship between the gear shift operation position and the traveling speed. )s (Gb)...Low speed transmission part % (Hl)...Main gear transmission 1. (Hl
)・・・・・・Auxiliary gear transmission device.

Claims (1)

[Claims] ■ Main gear transmission (Hl) and M-
This is a traveling transmission for a work vehicle, which is provided with two auxiliary gear transmissions (H, L), respectively, in which the auxiliary gear transmission (H3) is comprised of two low-speed side gears with different gear ratios. Transmission part (Ga)
, (cb), and a low connection side transmission section (Ga
) s (G b ) A traveling transmission device for a work vehicle, which is provided with a clutch mechanism □□□ for switching the operating state of the G b ). ■ The main gear transmission (2) and the auxiliary gear transmission (H
Hydraulic cylinder for gear shifter operation +10 for each of l)
1, flol, and ++21.