JPS604631A - Oil-hydraulically operated speed change gear - Google Patents

Abstract

PURPOSE:To prevent generation of shock at the time of clutching operation as well as to shorten the time till completion of said operation by controlling a flow control valve for cylinder and accumulator so that the pressure oil supply amount, before the cylinder supply oil pressure attains the accumulation commencing pressure of the accumulator, is greater than the supply amount thereafter. CONSTITUTION:An accumulator A to accumulate part of the pressure oil to be supplied to the cylinder in accordance with the clutching operation is furnished in order to raise slowly the oil to be supplied to oil-hydraulic cylinder S1. Pressure chamber (a) is put in communication with a drain oil line TR when a control valve V is in neutral state, and with an oil line PR on the pump side when the valve V is in the state of speed change operation. The cylinder supply oil pressure is put in communication with the cylinder by furnishing an orifice 18 at the part of piston 17 of accumulator A nearer to the base than the major dia. part so that the pressure oil supply amount before attainment of the accumulation commencement pressure of the accumulator will become greater than the pressure oil supply amount thereafter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a hydraulic cylinder for operating a multi-disc clutch for acceleration, and also provides a control valve for the hydraulic cylinder. The present invention relates to a hydraulically operated transmission equipped with an accumulator for accumulating parts.

Conventionally, in such a hydraulically operated transmission, a throttle valve is provided to reduce the flow rate of pressure oil supplied to the hydraulic cylinder and the accumulation lane, so as to provide a half-clutch state for a sufficient period of time when the clutch is engaged. , in this case, to prevent unpleasant shock from occurring.

The hydraulic cylinder that has been moved to the clutch disengagement side is operated to the clutch engagement side to bring the separated friction plates of the multi-disc clutch into contact with each other. Even when the cylinder is pre-activated for clutch engagement operation, the hydraulic cylinder is supplied. As a result of the reduction in the amount of pressurized oil, there is a disadvantage that the time from when the control valve is operated to when the clutch engagement operation is completed becomes longer.

More specifically, in the clutch disengagement state, the friction plates of the multi-disc clutch are maintained far apart from each other, and
It is necessary to suppress early wear of the friction plate, and for that purpose,
The hydraulic cylinder must be operated to return to the clutch disengaged side with a large stroke, resulting in an inconvenience that the cylinder pre-operation time for the clutch engagement operation becomes long, and there is room for improvement.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to enable the clutch engaging operation to be performed without unpleasant shock.F: The clutch engaging operation can be performed after operating the control valve without any damage. The aim is to shorten the time it takes to complete the process.

The characteristic configuration of the hydraulically operated transmission according to the present invention is that a flow rate regulating valve for the cylinder and the accumulator is configured to control the amount of pressure oil supplied before the cylinder supply oil pressure reaches the accumulation operation start pressure of the accumulator or a pressure close to it. In order to increase the amount of pressurized oil supplied after that, it is designed to be able to be automatically operated.

Next, the effects of the characteristic configuration of the present invention will be described.

In other words, when the hydraulic cylinder preliminarily operates to engage the clutch, the amount of oil supplied is large, and when the clutch is engaged while the accumulator is being operated to accumulate dJ, the amount of oil supplied is made to be small. be.

Therefore, while maintaining the half-clutch state for a sufficient period of time so that the clutch engagement operation can be performed without causing an unpleasant shock, the pre-operation time for the hydraulic cylinder's clutch engagement operation is shortened and the control is controlled. It is possible to shorten the time from valve operation to completion of clutch engagement operation, thereby providing a hydraulically operated transmission device that is more convenient to use.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a circuit diagram of a hydraulically operated transmission for traveling installed in a combine harvester. A multi-disc clutch (C1) that switches each of the forward 2-speed gear (G, ), the forward 8-speed gear (G3), and the reverse gear (Go) to a state where they rotate integrally with the transmission shaft. ), (Cri.

(C1), (CG), and clutch operation cylinders (51), (S2), (Sa
), (So) for each clutch (C1').
... are operated separately, and the clutch release side K1
It is a throw with 1 t of force applied.

Then, a pump (P
l, and the pressure oil from it to the hydraulic cylinder (S work)
A Rochley-type control valve (Vl) is provided to selectively supply power to the engine, so that three forward speeds and seven reverse speeds can be changed depending on the valve operation.

In order to slowly increase the hydraulic pressure supplied to the hydraulic cylinder (Sl), the pressure chamber ta+ is connected to the control valve (V) so that the accumulator (4), which accumulates a part of the pressure oil to be supplied to the cylinder when the clutch is engaged, is operated. In the neutral state, the drain oil path (
TR), and is connected to the pump side oil passage (PR) when the II control valve ty> is in a speed change operation state, thereby preventing the clutch engagement from being performed suddenly. This is to suppress the occurrence of unpleasant shocks associated with this.

However, the throat of the drain oil passage (TR) is opened to supply pressure oil to the clutch (Cs) for cooling; )・
・Low pressure relief valve, which sets the hydraulic pressure supplied to (
2) is a high pressure main relief valve.

To be more specific about the control valve fflK, as shown in Figs.
At the same time, a pair of left and right spools are attached to the bottom of the bottomed cylindrical spool (8A) on the outside of the mission booth for the opening (4) of the pump side oil passage (PR) and the drain oil passage (TR). Opening L51 along the circumferential direction,
+51 respectively, lined up in the spool rotation direction, and with a pump side opening (4) between the pair of drain side openings (5), (5).
At the same time, the two hydraulic cylinders (sl) and
・Speed change control oil passages (R+) and (R
2), (R3).

Entrances (Ul) and (Us) for each of (R4)
, (Us).

(Uo) are formed in a state lined up in the spool movement direction. In other words, the configuration of the valve part of the pump side oil passage (PR) consists of a concave groove (6) formed on the outer surface of the valve gauging (3) along the spool rotation axis direction, and a concave groove (6) that communicates with the inner end of the transmission case. An annular groove (7) along the circumferential direction of the spool, a pair of passages T8+ communicating with the inside of the casing, A pair of concave grooves (91, +91) formed along the circumferential direction on the outer surface of the spool (8A) O communicate only when operated.
, passages tiol, tlQ) that communicate the concave grooves t91, +91 with the inner space of the spool's cylindrical portion, and holes (!) formed along the circumferential direction of the spool that communicate with the pump-side opening (4) at the bottom of the spool. and its hole (
A passage (I2) that communicates between the inner space of the spool and the cylindrical part of the spool.
are provided respectively. In addition, the drain oil passage (the configuration of the TR offshore valve section includes a pair of drain openings (5), a drain outlet (5A)'k that communicates with one of the drain openings (5), and a valve casing (
4), and a pair of drain openings (5), (5
Connect the U-shaped groove 0 to the side of the pump (4
) is formed on the outer peripheral surface of the spool in a detour state.
Further, in the medium state, one of the passages is opened to discharge the pressure oil flowing into the casing from the annular groove (7) through the pair of passages +81 and +8+ marked Oa to the drain oil passage (TR). (8) and the U-shaped groove along the spool rotation axis direction, and a drain opening (5) communicating with the other passageway (8) and the drain outlet (5A). Recessed grooves (+5) along the spool rotation axis direction connecting the spools are formed on the outer circumferential surface of the spool 11J.

The accumulator consists of Figure 2 and %5.
As shown in figures (a), (b), and (c), the piston 07
1, the large diameter end (17A) 'k of the piston Uη does not come into sliding contact with the inner surface of the spool in a state where no pressure oil is accumulated, and
It is formed so that it comes into sliding contact with the inner surface of the spool due to the operation associated with the start of pressure oil accumulation, and the large diameter of the piston (+7) (
17A), there is an orifice (+8) t-
A passage (10) is formed and communicates with the groove (9).
) flows through the piston outer circumference and the piston end surface into the pressure chamber full! 1) in the oil passage with a large circumference, which causes IJ, and an oil passage with a small opening in which the pressure oil from the passage (IO) flows into the pressure chamber fa+ only through the orifice 08). (+7)
The accumulator tA+ is loaded in a state where it is opened and closed in accordance with the operation of the accumulator tA+, and the accumulator tA+ is also used as a flow rate regulating valve.

In short, the flow rate is adjusted so that the amount of pressure oil supplied before the cylinder supply oil pressure reaches a pressure close to the accumulation operation start pressure of the accumulator is larger than the amount of pressure oil supplied after that.

However, the piston (17) is provided so as to open the passage (lO) when the maximum accumulation operation is performed, and at the end of the clutch engagement operation, the pressure oil supply amount is reduced to a half-clutch state. The next step is to quickly increase the clutch operating pressure to a predetermined pressure.

However, (+9) in the figure is the lever for spool operation, (C of 2 is the spool positioning ball elastically biased toward the spool (8A) side, (2υ is *Oil passage for operation (R□)・
This is an oil passage forming plate that forms a part of the pump oil passage (PR), a part of the drain oil passage (TR), and a part of the drain oil passage (TR) in cooperation with the outer surface of the transmission case.

As shown in FIG. 6, the oil passage for gear shift operation (R Formation hole (sha).

C4) Through the cylinder (Ss)... and clutch (
C1) * Communicatively connected to *. In addition, FIG. 6 shows the installation part of the gear 'l' (G□) for the first forward speed as a representative example.

To explain the hydraulic cylinder (Ss) and the forward operating cylinder (Si) as a representative, as shown in FIG. (C) and the drain hole (2).
The ball deer purple is in the closing position when the clutch is closed, and the hydraulic cylinder (S work) starts contacting the clutch (C1).
Is the same body suppressed and retreated by the clutch (C1)?
A hydraulic cylinder (St): J! By slowing down the cylinder operating speed in the range immediately before contacting the clutch (C1), the piston (c) moves to the clutch (C1) &? : This is to prevent a sudden high torque transmission state from occurring at the time of starting contact.

In other words, the cylinder (Sl) is in the state before continuous operation, and the clutch (
Ct) When VC contact is started, a temporary but high torque transmission condition is caused due to the dynamic inertia of the piston (21), but this is to be avoided. In addition, as a means to reach the same purpose, the seventh
As shown in the figure, the VC may be configured such that the small diameter oil passage 4 communicating with the drain oil passage side hole (241) formed in the transmission shaft (2) is provided in a state in which it is surrounded as the piston moves.

The hydraulically operated gear shift device of the present invention is suitable for the traveling speed change of a working vehicle, but in addition to
It can be applied to various purposes such as slowing J speed.

Also, flow rate adjustment valve (r□), Crz), (17)
In addition to making effective use of the accumulator, a pilot pressure-operated flow rate adjustment valve is operated to increase when the cylinder supply oil pressure reaches the accumulation operation start pressure of the accumulator (accumulator) or a pressure close to it. Depending on the situation, it may be possible to provide it in various configurations, such as incorporating a pump oil path (PR) K.

[Brief explanation of the drawing]

The drawings show an example tray of a hydraulically-operated electric-speed loading box according to ``Zero Emissions'', Fig. 1 is a hydraulic circuit diagram, Fig. 2 is a cutaway rear view of the control intermediary part, and Fig. 3 (A). , (b), and (c) are the second
Ei, lower, no -no nine-line arrow view in the figure, 4th
The people in Figures (A), (B), and (C) are in Figure 8 (A). A sectional view showing the gilt advance l speed state corresponding to each of (b) and (c), a sectional view showing the operating state of the large V accumulator in Fig. 5 (a), (b), and (c), Figure 6 is M
Sectional view showing the multi-plate clutch stone part for tJ forward speed, No. 7
The figure is a sectional view of an application example.

Claims (1)

[Claims] ■ Multi-disc clutch for speed change (C1), (Cz),
(C3). Operating hydraulic cylinder (Sl) for (Co), (
S2). (Ss), '(So) k are provided, and their hydraulic cylinders (Sl), (Sri, (Sa),
It is a hydraulically operated transmission equipped with an accumulator (Al) that accumulates a part of the pressure oil for supplying the cylinder when the cylinder (SI) is engaged. ), (S2), (Sa)
, (So) and the flow rate adjustment valve for the accumulator (rl), Dz), (17) f: Pressure oil before the cylinder supply oil pressure reaches the accumulator operation ambient starting pressure of the accumulator (4) or a pressure close to it. A hydraulically operated transmission that is equipped to automatically control the opening in order to make the supply amount larger than the subsequent supply amount of pressure oil. Pressure oil from the hydraulic pump (tP) is passed through the pressure chamber (al) of the accumulation lake to the cylinder (St),
(52) , (Sa), and (SO) are formed in a circuit a, and the blood flow regulating valve is configured by a pair of valves having different opening degrees and fully communicating with the pressure chambers (al and the hydraulic pump ψ). The oil pressure according to claim 0, wherein the oil passages Cr1) and (r2) are provided in the accumulator in a state where they are opened and closed in accordance with the operation #J of the piston θ of the accumulator. Operated transmission.