JPH0384264A - Hydraulically-operated side clutch brake device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a trouble, e.g., an engine stop by providing a hydraulic actuator which is actuated by a hydraulic circuit for steering to operate a side clutch. CONSTITUTION:When an operation lever 39 is inclined rightwardly to operate it to a right reversing position, a second switching valve 35 is switched to the clutch side, and a right crawler is reversed and brought into a super earth cornering state. Simultaneously, control is made so that the relief pressure of a variable relief valve 36 is further increased. Thereby, an oil pressure passing through the relief pressure of a check valve 45 is increased to a value higher than that during an earth cornering state, a forced return amount of a change-speed lever 40 of a deceleration cylinder (hydraulic actuator) 44 is increased, and a static oil pressure continuously variable gear shifter 1 is further decelerated. Namely, when the static oil pressure type continuously variable gear shifter 1 is brought into a set cornering state, deceleration control is effected, and the degree of deceleration of the gear shifter 1 is increased as the degree of sharp cornering is increased.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hydraulically operated side clutch brake device for a crawler-type work vehicle such as a combine harvester or a transport vehicle, and more specifically, it relates to a hydraulically operated side clutch brake device for a crawler type work vehicle such as a combine harvester or a transport vehicle. The present invention relates to a hydraulically operated side clutch brake device which is equipped with a hydrostatic continuously variable transmission device that transmits power to these crawler traveling devices, and which is equipped with a hydraulic side clutch that operates on the same circumference as both of the crawler traveling devices.

[Conventional technology]

A vehicle using a crawler as a traveling device has a large ground contact area, and therefore has excellent ability to travel on rough roads and soft ground. On the other hand, when running on a hard road surface, the running resistance tends to be higher than that of a wheel-driven type, and especially when turning, there is always slippage between the crawler and the running ground, which tends to increase the running resistance. There is.

In addition, when turning with a crawler-type work vehicle, it is necessary to make gentle turns by disengaging the side clutch of the crawler on the inner side of the turn, turning with confidence by applying the brakes on the crawler on the inner side of the turn, and turning the crawler on the inner side of the turn in reverse. There are turning methods such as a super pivot turn by rotating. Among these turning methods, in pivot turns and super pivot turns, the crawler on the outside of the turn has a strong tendency to drag the crawler on the inside of the turn, so the load acting on the crawler on the outside of the turn increases further. In some cases, the driving condition became extremely unstable and the engine stopped.

[Problem to be solved by the invention]

In order for the crawler type work vehicle according to the prior art to perform turning without any problems, it is necessary for the operator to decelerate the hydrostatic continuously variable transmission for the crawler on the outside of the turn depending on the degree of the turn. Difficult to rotate,
Moreover, it became a nuisance.

The present invention automatically reduces the traveling speed when turning, and by focusing on the fact that the steering side clutch is hydraulically configured, automatic deceleration during high-load turning is streamlined. The purpose is to make the person do the following.

[Means to solve the problem]

Therefore, the present invention provides the hydraulically operated side clutch brake device described at the beginning with a hydraulic actuator that is operated by steering hydraulic circuit pressure for operating the side clutch, and the actuator is configured such that the circuit pressure is equal to or higher than a predetermined value. In this case, the hydrostatic continuously variable transmission is controlled to the deceleration side.

Further, the actuator may be arranged and configured to operate a speed change operating member attached to a trunnion shaft of the hydrostatic continuously variable transmission from a forward side toward a neutral side.

Furthermore, a neutral return biasing device is provided to return the hydrostatic continuously variable transmission to neutral by pressing and biasing a speed change operating member attached to the trunnion shaft in a predetermined direction with an operating member, and a single The operating member may be configured to be pressed in the predetermined direction by the actuator.

[For production]

In other words, in order to turn the aircraft, the side clutch for the crawler on one side is disconnected and operated, but since the side clutch is hydraulic, the steering valve is switched and pressure oil is applied to the steering hydraulic circuit pressure. The supply becomes the operating means of the side clutch. Then, the pressure of the steering hydraulic circuit increases due to the supply of pressure oil, and when it reaches a predetermined pressure, the hydraulic actuator operates and controls the hydrostatic continuously variable transmission to the deceleration side, resulting in a turning state. Then, the speed will be automatically reduced.

Further, normally, reverse movement in a work vehicle is mostly used occasionally, such as when changing direction of the vehicle, and is originally set at a high reduction ratio.

Therefore, even if the vehicle were to make a backward turn, there would be no particular inconvenience even if there was no further deceleration at that time. If the deceleration operation by the actuator is performed from the forward side to the neutral side, that is, it is activated only when turning in the forward direction, as in the configuration shown in FIG.

Furthermore, claim 3. With this configuration, it is possible to automatically decelerate the vehicle when the vehicle is in a turning state using only one actuator, regardless of whether the vehicle is traveling forward or backward.

〔Effect of the invention〕

Therefore, claim 1. The hydraulically operated side clutch brake device described above uses the existing steering hydraulic circuit to automatically decelerate when turning in a cost-effective and rational manner, thereby eliminating problems such as engine stoppage. Now you can avoid it.

Also, claim 2. In the hydraulically operated side clutch brake device according to claim 1. In addition to the effects of claim 3, the structure can be simplified since automatic deceleration is not performed when turning backward, and the structure can be simplified. In the hydraulically operated side clutch brake device according to claim 1. In addition to the effects of this, we were able to create a more rational device that can automatically decelerate when turning in both forward and reverse directions while having a low-cost structure with a single actuator.

〔Example〕

Figure 2 shows the structure inside the traveling system transmission case (8) of a combine harvester, which is one of the working vehicles, and the power from the engine (not shown) is transferred to a belt transmission mechanism (not shown) equipped with a tension clutch. The power from the output shaft (3) of the H8T (1) is transmitted to the input pulley (2) of the hydrostatic continuously variable transmission (hereinafter referred to as H3T) (1) through the first transmission shaft. (4) through the one-way clutch (5) and output pulley (7), the reaping section (
6).

The power from the first transmission shaft (4) is transmitted to the second transmission shaft (11) via the first gear (9) and the second gear (10), and the second transmission shaft (11) A first high speed gear (12) and a first low speed gear (13) are fitted on the outside so as to be relatively rotatable, and a shift gear (14) is fitted on the outside so as to be freely slidable with a spline structure.

On the other hand, the second high speed gear (16) and the second low speed gear (17) fixed to the third transmission shaft (15) mesh with the first high speed gear (12) and the first low speed gear (13). A medium speed gear (18) is fixed to the third transmission shaft (15).

With the above structure, the shift gear (14) can be slid -
By engaging the first high speed gear (12), medium speed gear (18>, and first low speed gear (13)), the power can be shifted to three stages of high, medium and low, and this power is transferred to the medium speed gear (18). 1
8) which meshes with the third gear (19).

A right side gear (21R) and a left side gear (21L) are fitted onto the support shaft (20) that supports the third gear (19) so as to be relatively rotatable, and left and right axles (22L)
, (22R)'s input gears (23R), (23L) are always engaged with the left and right side gears (21L), (21R). This allows the right or left side gear (
21R) and (21L) are slid against the third gear (19) to engage and separate them, and the power transmission is turned on and off to the sprocket (24a) of the crawler traveling device (24) shown in Fig. 3. Therefore, side clutches (25R) and (25L) are constructed between the third gear (19) and the left and right side gears (21L) and (21R).

Next, the structure for applying braking to one axle (22R) or (22L) will be described in detail.As shown in the figure, the fourth right gear (26R) and the fourth left gear (26R) are connected to the support shaft (20).
L) is relatively rotatably supported by a bearing, and a pair of fifth gears (29) are fixed to a fourth transmission shaft (27).
meshes with the right fourth gear (26R) and the left fourth gear (26L). A multi-plate hydraulically operated handbrake (28) is provided at one end of the fourth transmission shaft (27), and is connected to either the right side gear (21R) or the left side gear (21L).
) from the third gear (19), and then move the right fourth gear (26) away from the third gear (19).
R) or the left 4th gear (26L),
By operating the handbrake (28), one of the axles (22R) or (22L) can be braked.

Next, to explain in detail the structure for reversing one axle (22R) or (22L), as shown in the same figure, the sixth gear ( 37) is fitted onto the fourth transmission shaft (27) so as to be relatively rotatable, and the sixth gear (37) and the fourth transmission shaft (27)
A reversing clutch (30) is provided between the two. As a result, the right side gear (21R) or the left side gear (21R)
1L) to the right 4th gear (26R) or the left 4th gear as described above.
With the gear (26L) engaged, turn the reverse clutch (
30), the power from the second high-speed gear (16) is reversed and decelerated to 1/2, and the power is transferred to the axle (22R).
) or (22L).

Next, hydraulic actuators (31R) and (3) slide the left and right side gears (2LL) and (21R).
Hydraulic cylinder as 1L), handbrake (28)
The hydraulic oil supply structure to the reverse clutch (30) will be described in detail. As shown in Fig. 1, the hydraulic oil from the pump (32) is supplied to the left and right side gears (
Hydraulic cylinder (31R) for (21L), (21R)
), (31L) as well as the hydraulic cylinder (
The oil passage (34) from the side of 31R) and (31L) is connected to the second switching valve (35) for the handbrake (28) and the reverse clutch (30), and the oil passage (34)
A variable relief valve (36) is connected to. Then, the maximum relief pressure of the variable relief valve (36) variably operated by the operating lever (39) is determined by the hydraulic circuit (L) shown in FIG.
) is set at the maximum overall pressure.

Further, as shown in FIG. 1, the H8T (1) has a shift lever (40) as a shift operation member attached to its trunnion shaft (38) and a swing arm (40) as an operation member.
By applying pressure in a predetermined direction with 1), the H8T (
1) is equipped with a neutral return biasing device (A) for returning the vehicle to neutral. That is, the gear lever (40) has a V-shaped recess (40).
a), and this recess (40a) is formed in the swing arm (41).
) to support the roller (42) that engages and contacts the spring (43), and supports the opposite swing fulcrum side of the swing arm (41) to the spring (43).
) in the trunnion axis direction, the roller (42) settles on the bottom corner of the recess (40a).
8T(1) is configured to always try to return to the neutral state.

A deceleration cylinder (44) is provided as a hydraulic actuator for operating the speed change lever (40) from the forward side to the neutral position. This reduction cylinder (44) is operated by the pressure of the hydraulic circuit (L),
To explain in detail, a check valve (45) is provided in the oil passage (34).
A deceleration cylinder (44) is connected through the hydraulic circuit (L), and when the hydraulic pressure of the hydraulic circuit (L) exceeds a predetermined value, H8T (1) is activated.
When the vehicle is moving forward, the gear shift lever (40) is pushed toward the neutral side to perform a deceleration operation.

Next, the turning action of this embodiment will be explained in the case of right turning.

When the operating lever (39) is tilted to the right, the first switching valve (33) is switched at the right side clutch disengaged position, the right hydraulic cylinder (31R) is operated, and the right side clutch is disengaged. The aircraft makes a slow right turn. At this time, excess oil from the right hydraulic cylinder (31R) returns to the tank (T) from the oil path (34) through the variable relief valve (36) whose relief pressure is operated to the lowest value by the operating lever (39). It is.

Then, when the operating lever (39) is further tilted to the right and operated to the right braking position, the variable relief valve (36) is operated to increase its relief pressure, so that the extra power from the right hydraulic cylinder (31R) is increased. Oil can no longer pass through this relief valve (36) and flows into the second switching valve (35), resulting in a turning state in which the right crawler is braked. At this time, the second switching valve (35) is switched to the handbrake side by the operation lever (39), and the variable relief valve (35) is lower than the allowable pressure of the check valve (45).
6) becomes a high value, excess oil flows to the handbrake (28) and also to the deceleration cylinder (28).
44) also has a check valve (45) and a variable relief valve (3).
6) acts to control the deceleration of H3T(1).

In other words, the hydraulic circuit (L) using the variable relief valve (36)
The pressure rose above the predetermined value mentioned above.

Then, when the operation lever (39) is further tilted to the right and operated to the right reverse rotation position, the second switching valve (35) is operated to switch to the reverse clutch side, and the right crawler is reversed to a super turning state. become. At the same time, the relief pressure of the variable relief valve (36) is operated to be even higher, so the oil pressure passing through the check valve (45) becomes higher than that in the pivot turning state, and the pressure of the deceleration cylinder (44) increases. The amount by which the shift lever (4o) is pushed back increases, and the H8T (1) is further decelerated. (The gear shift lever (40) is never pushed back to neutral.) In other words, the H8T (1) is controlled to decelerate when it enters the set turning state, and as the turning becomes steeper, the H8T (1) is controlled to decelerate.
This also works to increase the deceleration rate of 8T(1).

Note that (46) is the manual gear shift operation lever of H8T (1), and (49) is the set pressure adjustment lever of the check valve (45).

[Another example]

A hydraulically operated side clutch brake device as shown below may also be used.

(2) As shown in FIG. 4, the deceleration cylinder (44) may be configured to act on the swing arm (41) in the neutral return biasing device (A).

In this case, automatic deceleration can be achieved with only one deceleration cylinder (44) in either the forward or reverse turning state.

(2) As shown in FIG. 5, a pair of deceleration cylinders (44), (44) may be arranged on both sides of the shift lever (40) in the swinging direction of the neutral return biasing device (A).

In this case, the two deceleration cylinders (44), (44) can perform automatic deceleration operations in forward and reverse turning states.

■ As shown in Fig. 6, a double-acting telescopic cylinder (44) is interposed in the middle of the operating rod (47) of the manual shift operating lever (46) of the H3T (1).
) is connected to the manual shift operation lever (46).
This switching valve (48
) may be connected to the oil path after passing through the check valve (45) in the hydraulic circuit (L).

Even in this case, one double-acting cylinder (44) enables automatic deceleration in forward and reverse turning states.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the hydraulically operated side clutch brake device according to the present invention, in which Fig. 1 is a hydraulic circuit diagram, Fig. 2 is a sectional view showing the internal structure of the transmission case, and Fig. 3 is a diagram showing the front part of the combine. The side view, FIG. 4, FIG. 5, and FIG. 6 are structural diagrams showing other embodiments of the control circuit for decelerating the hydrostatic continuously variable transmission. (1)... Hydrostatic continuously variable transmission, (24).
・・・・・・Crawler traveling device, (25R), (25L
)...Side clutch, (38)...
Trunnion shaft, (40)... Speed change operation member, (
41)... Operating member, (44)... Actuator, (A)... Neutral return biasing device.

Claims (1)

[Claims] 1. A hydrostatic continuously variable transmission device (1) that transmits power to a pair of left and right crawler traveling devices (24), (24) and these crawler traveling devices (24), (24). In addition, hydraulic side clutches (25R) and (25L) for steering the crawler traveling devices (24) and (24) are provided.
), the hydraulically operated side clutch brake device is equipped with a side clutch (25R), (25L).
), and this actuator (44) decelerates the hydrostatic continuously variable transmission (1) when the circuit pressure exceeds a predetermined value. A hydraulically operated side clutch brake device configured to be controlled from the side. 2. The actuator (44) is configured to operate the speed change operation member (40) attached to the trunnion shaft (38) of the hydrostatic continuously variable transmission (1) from the forward side to the neutral side. A hydraulically operated side clutch brake device according to claim 1. 3. The hydrostatic continuously variable transmission (1) is returned to neutral by pressing and biasing the speed change operation member (40) attached to its trunnion shaft (38) in a predetermined direction with the operation member (41). A return biasing device (A) is provided, and the operation member (41) is operated by the single actuator (44).
2. The hydraulically operated side clutch brake device according to claim 1, wherein the hydraulically operated side clutch brake device is configured to be pressed in the predetermined direction.