JPH01153848A - Operating structure for travelling of working vehicle - Google Patents

Abstract

PURPOSE:To enable a rapid starting operation without need for particularly providing a clutch for the purpose by providing a clutch operating valve mechanism for operating switchover to a clutch engaging condition and a clutch disengaging condition while providing the artificially operating tool of the clutch operating valve mechanism. CONSTITUTION:By steppingly operating a pedal in the maximum step-in position, as a clutch operating valve mechanism V2 is switched over to the disengaging condition of a clutch C2, an operating oil chamber 30 is connected to a tank T releasing the pressurization of a hydraulic piston 29 by a pressure oil to disengage the clutch C2. When the clutch operating valve mechanism V2 is switched over to the engaging condition of the clutch C2, the connection between the operating oil chamber 30 and the tank T is cut off while an oil-pressure control valve mechanism V1 feeds oil into the operating oil chamber 30 in the maximum pressure controlling condition, rapidly carrying out the pressurization of the hydraulic piston 29 by a pressure oil to suddenly engage the clutch C2. That is, the rapid engaging operation of the traveling friction clutch C2 can be carried out regardless of the existence of the oil-pressure control valve mechanism V1 to enable the rapid starting operation of a machine body.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a hydraulic piston for operating a friction clutch for traveling, and the hydraulic piston automatically operates when a shift gear of a traveling transmission device is switched. The operating means of the shift gear and the control valve of the hydraulic piston are linked so that the hydraulic piston is in the clutch disengaged position, and the hydraulic piston is automatically brought into the clutch engaged position as the shift gear is engaged. The present invention relates to a driving operation structure for a work vehicle provided with a hydraulic control valve mechanism that automatically and gradually increases the clutch engagement operation pressure of a piston.

[Conventional technology]

In the above-mentioned work vehicle, the operation of the traveling clutch necessary for switching the shift gear is automatically performed due to the linkage between the control valve of the hydraulic piston and the operating means of the shift gear, and the operation of the traveling clutch necessary for switching the shift gear is automatically performed, and the transmission device, forward/reverse switching device, etc. It is constructed so that switching of the traveling transmission device can be easily performed without requiring clutch operation. Furthermore, due to the action of the hydraulic control valve mechanism, each time a clutch engagement operation is performed in conjunction with a shift gear change, the clutch engagement operation pressure is gradually increased to alleviate the shift shock and start shock associated with a shift gear change. It was composed.

Conventionally, in this type of work vehicle, for example,
As disclosed in Japanese Patent No. 255, the driving clutch is operated only by automatic control in conjunction with the switching operation of the shift gear.

[Problem that the invention seeks to solve]

In the conventional case, when trying to enable sudden start operation of the aircraft in order to impact the packet into the earth and sand during packet work, a high-torque drive was required in the traveling device for the first start. It is necessary to apply a sudden force, and it is necessary to perform on/off operation of transmission to the traveling gear while maintaining the shift gear of the traveling gear in the engaged position;
This is due to the fact that the traveling clutch is operated only by automatic control in conjunction with switching gears, and therefore it is necessary to provide a clutch separate from the traveling clutch so that it can be operated manually. Ta.

An object of the present invention is to enable a sudden start operation without the need for a special clutch for this purpose.

[Means for solving problems]

The characteristic configuration of the present invention is that, in the operation structure for driving a working vehicle described above, the hydraulic piston is operated while the hydraulic control valve mechanism is maintained in a maximum pressure control state in which the clutch engagement operation pressure of the hydraulic piston is set to the maximum value. a clutch disengaged state in which the operating oil chamber is connected to the tank; and a clutch engaged state in which the connection between the operating oil chamber and the tank is cut off and the hydraulic control valve mechanism refuels the operating oil chamber in the maximum pressure control state. A clutch operating valve mechanism which can be freely switched is provided, and a manual operating tool for this clutch operating valve mechanism is also provided. The functions and effects thereof are as follows.

[For production]

When the clutch operating valve mechanism is switched to the clutch disengaged state, the operating oil chamber is connected to the tank, the force d of the hydraulic piston due to the pressure oil is released, and the clutch is disengaged. Then, when the clutch operating valve mechanism is switched to the clutch engaged state, the connection between the operating oil chamber and the tank is cut off, and the hydraulic control valve mechanism is in the maximum pressure control state, and the operating oil chamber is supplied with oil, and the hydraulic piston is driven by pressure oil. Pressure is applied rapidly and the clutch engages rapidly. That is, regardless of the presence of the hydraulic control valve mechanism, the vehicle can be suddenly started by rapidly engaging the traveling friction clutch.

〔Effect of the invention〕

Because of the clutch operation valve mechanism, the traveling clutch for simplifying the operation of the traveling transmission device can be used for sudden start of the aircraft, making it possible to improve the thrusting of packets, etc., and furthermore, the said traveling clutch Additionally, there is no need to provide a separate running clutch, making it economically advantageous.

〔Example〕

Next, examples will be shown.

As shown in Fig. 1, the output of the engine (not shown) is transmitted to the transmission case via the main clutch (CI), the input sleeve (1) for the traveling gear, and the input inner shaft (2) around the power take-off shaft. (3), and the rotational force of the input sleeve (1) is transmitted to the forward/reverse switching device (5) via the main transmission for traveling (4).
) is transmitted to the traveling auxiliary transmission (6) via the traveling friction clutch (C2), and this traveling auxiliary transmission (6)
The output of 6) is transmitted to the rear wheel differential mechanism (7) and the front wheel transmission shaft (
8) to constitute a transmission device for running and working of an agricultural tractor.

The main transmission for traveling (4) and the auxiliary transmission for traveling (6) each have two shift gears (9) and (lO) or (11).
) and (12), the gears can be changed in four stages. In other words, the overall speed can be changed to 16 forward speeds and 16 reverse speeds, and the speed change is performed based on the operating structure shown in FIG. 2.

That is, one shift gear (9) of the main transmission (4)
is connected to the first hydraulic cylinder (
13), and the other shift gear (10) is connected to the second hydraulic cylinder (14) via the shifter yoke (10a).
), and
One shift gear (11) of the auxiliary transmission (6) is connected to a third hydraulic cylinder (15) via a shifter yoke (lla).
In addition, the other shift gear (12) is configured to be switched by the fourth hydraulic cylinder (16) via the shifter yoke (12a), and all the hydraulic cylinders (13) to 16) are switched. one rotor,
This is connected to the high speed pulp (17). This variable speed pulp (17) has a neutral operating position (N) and 16 transmission operating positions (1) to XVI), and the operated neutral operating position (N) or transmission operating position (1) or...
The hydraulic cylinder (
13) to 16).

The shift gear (1st) of the forward/reverse switching device (5) is configured to be switched by a manually operated forward/reverse lever (19) via a shifter yoke (18a).

A pair of first gear switching pistons (20a) and (20b) are installed in the second hydraulic cylinder (14), and a pair of second gear switching pistons (21a) are installed in the third hydraulic cylinder (15).
.

(21b), and are automatically connected to the operating oil chambers of the first gear switching pistons (20a) and (20b) by the flow path switching valve (22). (20b) is connected to the first hydraulic cylinder (13) via the interlocking mechanism (25), one of the two control valves (23) and (24) for operating and releasing the control valve (20b);
The other control valve (24) is interlocked with the forward/reverse lever (19) via the interlocking mechanism (26) to operate and release the second gear cutting pistons (21a) and (21b). (27) to the fourth via the interlocking mechanism (28).
It is linked to the hydraulic cylinder (16). And the first
When the hydraulic cylinder (13) switches the shift gear (9), the control valve (23) is switched to the operating position (b) for the cylinder power, and the forward/reverse lever (19) is switched to the operating position (b). ), when the shift gear (18) is switched, the control valve (24) is switched to the operating position (b) due to the human operating force, so that in any case, the control valve (24) is switched to the operating position (b). The first gear cutting pistons (20a) and (20b) are driven by oil supply from the hydraulic pump (P), and at this time, the second hydraulic cylinder (
14) is also supplied with oil from the same hydraulic pump (P), but the first gear switching piston (20a)
(20b) is larger than that of the cylinder piston.
(a) and (20b) are configured to operate the second hydraulic cylinder (14) to the shift gear off state with priority over oil supply from the speed change valve (17). When the first hydraulic cylinder (13) completes the operation to engage the shift gear (9), the control valve (23) accordingly switches to one of the release positions (a) due to its self-restoring force. By this, the shift gear (18) by the forward/reverse lever (19)
When the input operation is completed, the control valve (
24) is in either one of the release positions (
By switching to a), in either case, the first gear switching pistons (20a) and (20b) are in the released state and the second hydraulic cylinder (14) is in the shift gear (10).
It is configured to allow operation of the switch to either one of the entry positions. Then, the first hydraulic cylinder (13
) and the first gear cutting piston (20a), (20b)
For a configuration similar to the interlocking configuration of the fourth hydraulic cylinder (
16) operates the shift gear (12),
The control valve (27) is switched to the operating position (b), and the second gear switching pistons (21a) and (21b) shift the third hydraulic cylinder (15) to a shift gear with priority over oil supply from the speed change valve (17). When the fourth hydraulic cylinder (16) completes the operation to engage the shift gear (12), the control valve (27) returns to one of the release positions (a).
), the second gear switching piston (21a) and (
21b) is the third hydraulic cylinder (15) is the shift gear (1
1) can be operated to either one of the entry positions. In other words, when the upper main transmission section (4a) of the shift gear (9) is switched, the main transmission section (4b) located on the downstream side is switched to the lower side auxiliary transmission section (4a) of the shift gear (12). 6b), the auxiliary transmission section (6b) located above this, and when the forward/reverse switching device (5) switches, the downstream main transmission section (4b) located above this, respectively. The transmission is automatically and temporarily turned off.

The clutch (C2) is configured to be operated by a hydraulic piston (29) inside the clutch body, and
The hydraulic piston (29) is operated by a two-position switching type first control valve (31a) and a three-position switching type second control valve (31b) connected in series to the operating oil chamber (30) of the hydraulic piston (29).
29), and when at least one of the first control valve (31a) and the second control valve (31b) is in the refueling release position, the control valve (31)
is in the clutch disengaged position, and both the first control valve (31a) and the second control valve (31b) are in the refueling position, so that the control valve (31) is in the clutch engaged position.

The second control valve (31b) is interlocked with the second hydraulic cylinder (14) via the interlocking mechanism (32), and the pilot operation valve (33) connected to the pilot pressure operation section of the first control valve (31a) ) is interlocked with the third hydraulic cylinder (15) via the interlocking mechanism (34), so that the hydraulic piston (29) is automatically activated when each of the shift gears (9) to 12) and (18) is switched. The clutch is in the disengaged position and the shift gears (9) or 12) and (
18) The hydraulic cylinder (
13) to 16) and the forward/reverse lever (19) are linked with the control valve (31). That is, the second
When the hydraulic cylinder (14) operates to switch the shift gear (10), the second control valve (31b) switches to the refueling release position (a) due to its self-restoring force, and the second hydraulic cylinder (14) When the shift gear (10) is engaged, the second control valve (31b) is switched to one of the refueling positions (b) due to the cylinder operating force. Then, when the third hydraulic cylinder (15) operates to switch the shift gear (11), the pilot operation valve (33) moves to the refueling release position (
a), the first control valve (31a) switches to the refueling release position (a) due to its self-restoring force, and the third hydraulic cylinder (31a) switches to the refueling release position (a).
15) completes the operation of shifting gear (11),
Along with this, the pilot operated valve (
33) will eventually switch to one of the refueling positions (b) and
The control valve (31a) is in the refueling position (
b). In other words, this control valve linkage,
Due to the above-mentioned linkage structure for automatic time switching of the lower main transmission section (4b) and the upper main transmission section (6a), when at least one of the shift gears (9) to 12) and (18) is operated to switch. , along with this, the first control valve (31a)
When at least one of the first control valve (31b) and the second control valve (31b) automatically enters the refueling release position (a) and all shift gears (9) to 12) and (18) enter the on position, the first control valve (31a ) and the second control valve (31b) are both in the refueling position (b).

A hydraulic control valve mechanism (V1) is provided between the control valve (31) and the operating oil chamber (30). This hydraulic control valve mechanism (V1)
The pressure oil from the control valve (31) is first passed through the low-pass valve (
35) to the operating oil chamber (30).
30) reaches the set low pressure, the low-pass valve (35) automatically switches to close due to the back pressure from the operating oil chamber (30), and the accumulator (30) passes through the throttle valve (36).
Oil is supplied to the operating oil chamber (30) while accumulating pressure in the operating oil chamber (37), and when the oil pressure in the operating oil chamber (30) reaches the set high pressure, the bypass valve (38) is automatically switched to open due to back pressure and this bypass is closed. By supplying oil to the operating oil chamber (30) through the valve (38), the clutch-engaging operating pressure of the hydraulic piston (29) is automatically and gradually increased, and the control valve (
31) is switched to the clutch disengaged position, the pressure accumulated by the accumulator (37) is released through the oil passage (39) with a check valve, so that each time the control valve (31) switches from the clutch disengaged position to the clutch engaged position, The pressure is increased gradually.

In short, by switching the speed change valve (17), the first and second hydraulic cylinders (13).

(14) Main transmission for traveling using hydraulic power (4)
, and the third and fourth hydraulic cylinders (15), (
The auxiliary transmission device (6) for traveling is switched by the hydraulic power generated by the hydraulic power of the gearbox (16), and by swinging the forward/reverse lever (19), the forward/reverse switching device (5) is manually operated.
) is switched. During any switching operation, the necessary clutch (C2) operation is automatically performed using hydraulic power from the hydraulic piston (29), and the hydraulic control valve mechanism (V1) prevents gear shift shocks. This is done to alleviate the shock of starting. Furthermore, switching between the upper main transmission section (4a), the lower auxiliary transmission section (6b), and the forward/reverse switching device (5) is performed by the lower main transmission section (4b).
Alternatively, by attempting to prevent the dynamic inertia of the rotating member in the non-switching target part from being transmitted to the switching target part by the switching operation of the upper sub-transmission part (6a), it is possible to ``facilitate synchronization of the switching target part. It will be done.

A clutch operating valve mechanism (V2) is provided between the hydraulic control valve mechanism (Vl) and the operating oil chamber (30), and the clutch operating valve mechanism (V2) is connected to the foot pedal (41) via the interlocking mechanism (40). The clutch operating valve mechanism (V2) is constructed as shown in FIG. 3, by operating the clutch (C2) to quickly engage the clutch (C2) and adjust the engagement pressure.

That is, a valve body (43) is attached to a valve case (42), and a first spring (44) is applied to one end side of this valve body (43).
, and two second valves acting on the other end side of the valve body (43).
In addition to installing springs (45) and (46),
The spring receiver (47) that acts on the side opposite to the valve body side of the second springs (45) and (46) is attached to the valve case (41).
) is installed through one end side. The valve body (43) slides along the stopper and guide (48), and as shown in FIG. 4, the outer peripheral groove (49) as shown in FIG.
, communicates with the pump port (P) via the valve seat inner circumferential groove (51) and the valve seat hole (52), and the valve seat hole (53).
It penetrates into the cylinder port (C) through the operating oil chamber (
30) to the hydraulic control valve mechanism (Vυ and the control valve (31), as shown in FIG.
0) comes off from the inner circumferential groove (51) of the valve seat, and the outer circumferential groove (49)
) communicates with the cylinder port (C) and also communicates with the tank port (1) via the second notch (54) and spring chamber (55) as shown in FIG. Control valve mechanism (for Vυ, the tank (
T) is the oil draining position where the connected state is established, and as shown in Fig. 3, the outer peripheral groove (49) communicates with the cylinder port (C), and the first notch (50) connects to the valve seat inner peripheral groove. (5I), the second notch (54) comes off from the spring chamber (55), and the operating oil chamber (30) is connected to the control valve (31) and the tank (
The neutral position is sandwiched between each neutral position to be in a disconnected state with respect to T).

The pressure oil back pressure from the hydraulic piston (29) acting on the pressure receiving parts (57) and (58), which are provided inside the valve body that communicates with the through hole (56) in the outer peripheral groove (49), and the The first spring (44) biases the valve body (43) to the oil draining position, and the second springs (45) and (46) bias the valve body (43) to the oil drain position.
3) to the refueling position, and as the pedal (41) is rocked, the spring receiver (
47) is slidably adjusted for the pedal return spring (59) and the second springs (45) and (46) to adjust the biasing force of the second springs (45) and (46).

That is, when the pedal (41) is in the non-depressed position (ON), the spring receiver (47) is pushed in by the pedal return spring (59) and the second spring (
45) and (46) to the set maximum value, and until the clutch engagement operating pressure reaches the set maximum value, the valve body (
43) is operated to the oil supply position by the second springs (45) and (46) to enable oil supply from the hydraulic control valve mechanism (Vl) to the operating oil chamber (30), and with this oil supply, the clutch When the engagement operation pressure reaches the set maximum value, the pressure oil that operates the hydraulic piston (29) to the clutch engagement position, the biasing force of the first spring (44), and the second spring (45)
) and (46) are in balance, the valve body (43) is placed in the neutral position, and the clutch engagement operating pressure is maintained at the set maximum value. In other words, the clutch operating valve mechanism (V2) is in the clutch engaged state.

When the pedal (41) is depressed to the maximum depression position (OFF), the spring receiver (47) is pushed out to the stroke end by the second springs (45) and (46), and the second spring (45) and (4
6) Decrease the biasing force to the set minimum value, and then press the valve body (43).
is in the oil drain position due to back pressure and the first spring (44), and by closing the pump port side, it is possible to release pressure from the operating oil chamber (30) while applying back pressure to the hydraulic control valve mechanism (V1). It is to make it. That is, the clutch (C2
), the clutch operating valve mechanism (V2) is in a state where it is turned off. Then, the pedal (41) is in the non-depressed position (
When the spring receiver (47) is depressed to an operating position between the operating position (ON) and the maximum depression position (OFF), the spring receiver (47) is moved to the intermediate mounting position due to the balance between the operating force and the second springs (45) and (46). and the second spring (4
5) and (46) are adjusted to an intermediate value between the set maximum value and the set minimum value, and the valve body (43)
Because of the spring (44), it becomes the oil drain position and allows pressure relief from the operating oil chamber (30), and with this pressure relief, the back pressure and the biasing force of the first spring (44) and the second spring (44) are released. When the biasing forces of 45) and (46) are balanced, the valve body (43) becomes the neutral position and the clutch engagement operating pressure is increased to a value determined by the adjusted biasing forces of the second springs (45) and (46). maintain it. That is, the clutch operating valve mechanism (V2) enters a state in which the clutch (C2) is engaged at an operating pressure lower than the set maximum value while maintaining the hydraulic control valve mechanism (Vl) in the maximum pressure control state.

Therefore, by depressing the pedal (41) to the maximum depressing position (OFF), operating the clutch (C2) to disengage, and then returning the pedal (41) to the non-depressing position (ON), the highest pressure control state can be achieved. Hydraulic control valve mechanism (V
1), pressure oil is rapidly supplied to the operating oil chamber (30), and the clutch (C2) is rapidly engaged. Then, by depressing the pedal (41) to the maximum depressing position (OFF), some pressure is released from the operating oil chamber (30), and the clutch (C2) is brought into a half-clutch state. The ring can be adjusted.

[Another example]

FIG. 7 shows another embodiment of the hydraulic control valve mechanism (Vl), in which the hydraulic pressure in the operating oil chamber (3o) is set by the balance between the back pressure from the operating oil chamber (30) and the pressure setting spring (60). Operate the pressure regulating valve (61) between the oil chamber (3o) and the first control valve (3o).
1a), and the set pressure by the pressure setting spring (61) increases as oil is supplied to the piston (62) that changes and adjusts the biasing force of the pressure setting spring (60) and the operating oil chamber (30). An oil passage (63) for operating the piston (62) in such a manner is attached to the pressure regulating pulp (61).

Pressure control valve mechanism (Vl) and clutch operation valve mechanism (V2)
and may be implemented by configuring them into one valve structure.

The present invention is also applicable to the case where switching of at least one of the main transmission for traveling (4), the auxiliary transmission for traveling (6), and the forward/reverse switching device (5) is linked with the operation of the clutch (C2). The main transmission for traveling (4), the auxiliary transmission for traveling (6), and the forward/reverse switching device (5) are referred to as traveling transmissions (4), (5), and (6), and the hydraulic cylinder (13) or 16) and forward/reverse lever (
19) as the operating means (13) or 16) and (19)
It is called.

The clutch operation valve mechanism (V2) is operated using the foot pedal (4).
Instead of 1), it may be configured to use a manual lever.
These are referred to as human operating tools (41).

In addition to agricultural tractors, the present invention can also be applied to various work vehicles such as transport vehicles.

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 the drawing]

The drawings show an embodiment of the operation structure for driving a work vehicle according to the present invention, in which FIG. 1 is a sectional view of a transmission device, FIG. 2 is a hydraulic circuit diagram, and FIG. 3 is a sectional view of a clutch operating valve mechanism. 4 and 5 are cross-sectional views of the valve body arrangement portion, FIG. 6 is a plan view of the valve body, and FIG. 7 is a schematic diagram of another hydraulic control valve mechanism. (4), (5), (6)...Traveling transmission, (9), (10), (11), t12), (
18)...Shift gear, (13), (14)
), (15), (16), (19)...
...Operating means, (29) ...Hydraulic piston,
(30)...Operating oil chamber, (41)...
Human operating tool, (Vl)...Hydraulic control valve mechanism, (
V2)...Clutch operation valve mechanism.

Claims (1)

[Claims] 1. A hydraulic piston (29) for operating a traveling friction clutch (C_2) is provided, and a traveling transmission device (4);
(5), (6) shift gears (9), (10), (11)
), (12), (18), the hydraulic piston (29) automatically moves to the clutch disengagement position, and the shift gears (9), (10), (11), (1
2) and (18), the hydraulic piston (
The shift gears (9), (10), (11), (12), (1
8) operating means (13), (14), (15), (16)
), (19), and a control valve (
31) is provided with a hydraulic control valve mechanism (V_1) that automatically gradually increases the clutch engagement operating pressure of the hydraulic piston (29),
The hydraulic control valve mechanism (V_1
) while maintaining the clutch disengagement state in which the operating oil chamber (30) of the hydraulic piston (29) is connected to the tank (T), and the connection between the operating oil chamber (30) and the tank (T) is disconnected. a clutch operating valve mechanism (V_2) that can be freely switched between a clutch engaged state and a clutch engaged state in which the hydraulic control valve mechanism (V_1) supplies oil to the operating oil chamber (30) in the maximum pressure control state;
An operation structure for running a work vehicle, which is provided with a manual operation tool (41) for this clutch operation valve mechanism (V_2). 2. The structure according to claim 1, wherein the traveling transmission devices (4) and (6) are traveling transmissions. 3. The structure according to claim 1, wherein the traveling transmission device (5) is a forward/reverse switching device.