JPS59106749A - transmission device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a shifter operated by a hydraulic cylinder in a transmission, and a pilot pressure pulp that is opened and closed as the shifter is switched between a transmission state and a non-transmission state. The present invention relates to a transmission device in which a valve mechanism for operating a clutch provided in series with the device is provided so as to be operated by opening and closing the pulp, and the clutch is configured to automatically operate in conjunction with a gear change operation.

In the above-mentioned transmission device, conventionally, the pilot pressure valve is configured by applying pilot pressure to the valve mechanism when the shifter is in the operating state, operating the clutch to engage the transmission, and at the same time, the shifter is in the non-transmission state. At that point, the pilot oil passage for the valve mechanism was connected to the drain passage and the clutch was configured to be operated to disable the transmission, but due to the time required to release the pilot pressure when communicating with the drain passage, the shifter was not activated. There was a problem that the synchronization of the clutch disengagement operation was reduced, resulting in a lack of smooth gear shifting operation.

Particularly in cold seasons, the above-mentioned tendency becomes even stronger because the viscosity of the hydraulic oil increases.

In view of the above-mentioned conventional situation, the purpose of the invention is to improve the pilot pressure pulp so that the pilot pressure can be released appropriately in order to better synchronize the shifter's operation to the non-transmission state and the clutch disengagement operation. The purpose of this invention is to improve the durability of the pilot pressure pulp.

An uninvented characteristic configuration is that in the above-mentioned transmission device, in the hydraulic cylinder, the peripheral surface K of the piston rod, which constitutes the pulp for pilot pressure, is connected to and disconnected from the drain path as the peripheral surface K of the piston rod slides. When the switching groove is formed to extend longitudinally in a part of the circumferential direction of the piston rod, the boat for the pilot oil passage to the valve mechanism is connected to the drain passage as the piston rod slides. The cylinder tube is formed with a groove arranged so as to be selectively connected to the cylinder chamber, and its functions and effects are as follows.

In other words, when the shifter is in the transmission state, the pressure oil supplied to the cylinder chamber is supplied to the valve mechanism as pilot pressure oil for the sliding of the piston rod, and when the shifter is in the non-transmission state, the pilot oil is supplied to the valve mechanism as pilot pressure oil. The pilot oil passage is connected to the drain passage via a groove to release pilot pressure, and by forming the groove to extend in the longitudinal direction of the piston rod, the pilot oil passage is connected to the drain passage through a groove. can be connected to the drain path and pilot pressure release can be started, allowing sufficient time for pilot pressure release, and as a result, the time when the shifter completes operation to the non-transmission state and the clutch disengagement operation can be started. By appropriately synchronizing the completion point with the time of completion, it has become possible to make the gear shifting operation extremely smooth.

Moreover, since the groove is formed only in a part of the circumferential direction of the piston rod, the sliding contact area between the piston rod and the cylinder tube is reduced compared to, for example, forming the groove as an 11-wide annular groove. It was possible to maintain a large amount of pressure, suppress early wear and damage between the piston rod and cylinder tube due to an increase in sliding contact pressure, and significantly improve the durability of the pilot pressure pulp.

Next, a non-inventive embodiment will be described in detail based on illustrative drawings.

As shown in Fig. 1, power from the engine (Elf) is transferred to the main transmission (1), hydraulic multi-disc clutch (2), sub-transmission I# (3), and switching device for starting/decelerating ( 4) in that order, and the power taken out from the super deceleration switching device (4) is transmitted to the pair of left and right rear wheels (6) via the rear wheel differential device (5), and to the transmission shaft ( 7) and a front vehicle differential gear (1a), the transmission is transmitted to a pair of left and right front wheels for steering (!), respectively. It is configured so that the power branched from the hand side is transmitted to the power take-off shaft (6)K for driving the work equipment via the power take-off speed change i If (10) and the hydraulic multi-disc clutch 0υ, and This constitutes a drive device for a finishing wheel such as the following.

As shown in Figs. 1 and 2, P(1), (3), (41, H) during each of the above-mentioned gear shifts are composed of the 9th position m (N) of the rotary set including the neutral position (N). , Fl~F
, ) The two speed shifters (
a).

(h) Actuators for operation (18a), (18b)
, and - by integrally operating the actuator Q411 for operating the high/low speed switching shifter (C) in the auxiliary transmission (3), the 4-speed shift in the main transmission (1) and the auxiliary transmission (3) are performed.
In addition, the auxiliary transmission (3) is configured to perform a two-speed shift at Forward/reverse switching shifter (d) This is configured to operate the operating actuator aθ to obtain an 8-speed state for forward/reverse travel.

Then, the mechanically operated shift device OQ operates the progressive deceleration switching device M (4) to switch between the normal deceleration state and the super deceleration state. The front wheel drive transmission shaft (7)
The vehicle is configured to switch between a two-wheel drive state and a four-wheel drive state by intermittent operation of power transmission to the vehicle.

Also, the 5th position I of the rotary set including the neutral position fW (n)
The power take-off system speed change valve (right) configured in the ff(n, f, ~f,) switching valve allows the two-speed change shifter (d) and (e) in the power take-off transmission OI to be operated by the actuator ( 18a) and (18h) are integrally operated to perform a four-speed power take-off system. (P) in the figure is an operating shaft directly connected to the transmission case (M) input shaft (SI). It is a pressure oil supply pump.

To operate the clutches (2), Ql), as shown in FIG. 2, the actuators (18a),
(x8b), Q41, QFj, (18a), (
18b) in which the piston rod OI is also used as a sliding spool -t'-tut et al. actuator (1
8a), (lah), 04, Ql.

Six 8-position switching valves (x, ``'') prevent the flow of pressure oil from the corresponding valves (Vt), (Vt), (■) only when (18a) and (18b) are in the neutral position.
Six two-position switching valves (y.

~yi), eight of the running system (Vt), (Ys)-
tYi) to engage the travel system hydraulic clutch (2), and ytb
The two power take-off system parts 1) and (9) are configured to automatically operate the power take-off system hydraulic clutches 0υ in accordance with the speed change operations of the respective valves (Vt), (Vt), and (Z). .

In the same figure, (E) is the relief valve Q for the pump CP).
A pair of clutches (2) that also uses the p circuit, O which is an Oυ lubricating oil supply path, and the actuators (18a), (18h), (18a
) and (18b), as shown in FIG. 8 and FIG. The rod side small diameter portion (22b) is formed, and the bottom side large diameter portion (22a) is provided with a sliding member (c) that divides it into two parts, the bottom side and the piston rod side. The large diameter portion on the side (22a) and the small diameter portion on the piston rod side (22h) are connected to oil passages from the traveling system transmission valve (tit) or the power extraction system transmission valve (V,), respectively. V,)
, (V,), shifter (a)
, (hl, (d), (e) to shift position 4■
When installing the piston rod, both bottom side large diameter portions (22a) and one piston rod side small diameter portion (22h) are drained of oil, and the other piston rod side small diameter portion (22h) is drained.
2b), and the sliding member on the side receiving the pressure oil supply (
After sliding the shifter (a) to the bottom end, extend the piston rod θ and move the shifter (a), (hl,
Shifters (a), (b), (d),
(e) When switching from the gear shift position to the neutral position, pressurized oil is supplied to both the bottom large diameter parts (22a) while the small diameter parts (22b) on both piston rod sides are drained, and the oil is supplied to the large diameter parts (22a) on the bottom side, The shifter (a) is moved toward the position by the abutting and pressing action of the piston rod OI of the moving member
, (h), (d), and (e) return to the neutral position, and in the neutral position, the position regulating action of both sliding member wings on the piston rod 01 in the pressurized oil supply state , shifter (a), (h)
, (d).

(e) is oval shaped to hold it in a neutral position.

To configure the pilot pressure 8-equipped switching valve (xs-3(+)), connect the boat (c) connected to the pilot oil passage (c) for the 2-position switching valve (y$~phantom) to the piston rod side of both cylinders. The small-diameter portion (22b) opens near the end of the piston rod a side, and both communicate with the drain space CD outside the cylinder wall due to the sliding of the piston rod and the non-communicating state. A pair of switching groove rings is formed in a part of the circumferential direction of the piston rod α flawed circumferential surface.

And shifters (a), (b), (d),
When (e) is in any of the gear shifting states, one of the boats (c) is in the non-communicating groove (c) as shown in FIG.
The other boat (c) is disconnected from the groove ring and communicated with the piston rod side small diameter portion (22b) that is supplied with pressure oil, and is connected to the pilot oil passage (c). Also, shifter (a) so that pressure oil is supplied.
, Φ), (d), and (e) slide a little from the gear shift position to the neutral position, as shown in Figure 8, both boats (
The groove (E) is formed in a shape extending in the longitudinal direction of the piston rod 0I so that the groove (E) is communicated with the co-trap drain space (D) via the groove (E) and pilot pressure release is started. Therefore, shifters (a), (11), (d)
.

By allowing sufficient pilot pressure release time before shifter (e) reaches the neutral position, shifters (a) and (b)
, (d) , (so that the disengagement of clutch (2) and Oυ is not delayed due to the time required to release the pilot pressure with respect to the operation of el to the neutral position,
In order to perform gear shifting operations smoothly, the sliding contact area between the piston rod 01 and the cylinder (A) is increased by forming the groove (E) only on a part of the circumferential surface of the piston rod 01 in the circumferential direction. The structure is such that the durability of the 8-position switching valve (Xs to x,) is improved by maintaining the 8-position switching valve (Xs to x) by suppressing early wear between the piston rod Ql and the cylinder due to an increase in sliding surface pressure.

Leap, shifter (a), (b), (d), (
Clutch (2), Ql) operation valves ゛(y), (V
*), 0's), (Clutch (2) by VJ.

The specific operation structure of Ql) can be changed in various configurations, and these valves 0's), (J's), 0's)
, 0's), the clutch (2), αυ operation structure is collectively referred to as the clutch operation valve mechanism (y), (y'), and the shifter (a), (b), (di, (
The gear changeover structure of e) consists of each shifter (→, (h),
Instead of providing two shift states for one neutral state in (d) and (e), one neutral state and one shift state may be provided. ) (Rubu genus), (XI) I (XI), (XI
) may be configured as a two-position switching valve.

Furthermore, the specific sliding switching structure of the piston rod (l!1) is also applicable to shifters (a), (b), (d).
, (e) Instead of returning to neutral by supplying pressurized oil, various configuration changes are possible in which a spring or the like is used to bias the neutral return.

In addition, the specific structure of the drain passage that communicates with the groove (A) as the piston rod θ1 slides can be changed in various ways, and these passages are collectively referred to as the drain passage CD). The invention is directed to various transmission devices equipped with hydraulically operated transmissions for various equipment such as agricultural and construction equipment.

[Brief explanation of drawings]

The drawings illustrate an embodiment of the transmission device according to the invention, FIG. 1 is an overall schematic plan view showing the drive structure, FIG. 2 is a hydraulic circuit diagram, FIG. 8 is an enlarged sectional view showing the shifter operation structure, and FIG. FIG. 4 is an IV-TV line diagram of the piston rod in FIG. 8. (υ...Transmission, (2)...Clutch, (11...Piston rod, (2)...
... cylinder, (22b) ... cylinder chamber,
(c)...Pilot oil path, (b)...
・Boat, (a)...ditch, (y)...
Valve mechanism, (D)...Drain path, (Xs), (
XI)... Pulp for pilot pressure, (a). (1))...Shifter 9

Claims (1)

[Claims] The transmission device (υ is provided with shifters (a) and (b) operated by a hydraulic cylinder (a), and the shifter (a)
, (h) Pilot pressure pulps (xg), (x+) that are opened and closed when switching between transmission state and non-transmission state
and a clutch (
2), the valve mechanism (y) for operating the pulp (X, ),
A transmission device provided to be operated by opening and closing the pilot pressure pulps (Xs), (x
4), in the hydraulic cylinder (a),
A groove ring that switches between a connected state and a non-connected state with respect to the piston rod (in the surface of the piston rod and the drain path υ as it slides) is formed in a state that extends in the longitudinal direction in a part of the circumferential direction of the piston rod 0. At the same time, as the piston rod 01 slides, the boat (c) for the pilot oil passage (goods) to the valve mechanism υ) is connected to the groove (c) connected to the front Re drain passage 0, and the cylinder chamber. A transmission device characterized in that it is arranged so as to be alternatively connected to (22h) and formed in a cylinder (b) tube.