JPH06100269B2 - Operation structure for traveling of work vehicle - Google Patents

Description

The present invention relates to a plurality of hydraulically-operated friction clutches that exhibit a transmission state for traveling and one operation for selectively entering and operating these friction clutches. An operating structure for traveling of a work vehicle in which a valve is provided and a hydraulic pressure adjusting mechanism for gradually increasing the operation pressure of the friction clutch is linked to the operation valve in a state in which the hydraulic adjustment mechanism is automatically operated in accordance with the switching operation of the operation valve. Regarding

[Conventional technology]

The work vehicle is configured to change the traveling speed or switch between forward and backward movements by operating the clutch by operating the operation valve. In addition, when shifting or switching between forward and reverse, the clutch engagement pressure is gradually increased due to the hydraulic pressure adjustment mechanism so that the switching shock is alleviated.

In this type of work vehicle, a friction clutch is conventionally provided in addition to a hydraulic clutch for gear shifting and forward / reverse switching, as shown, for example, in Japanese Patent Laid-Open No. 57-87717. It was configured to be able to perform rapid transmission for sudden start of the aircraft and half-clutch transmission for slow start of the aircraft and escape from wetlands by operating.

[Problems to be Solved by the Invention]

In the case of conventional vehicles, a clutch for enabling gear shifting and forward / reverse switching by operating the operating valve and a clutch for enabling rapid transmission or half-clutch transmission are required separately, which is disadvantageous in terms of structure and cost. It was.

It is an object of the present invention to enable rapid transmission and half-clutch transmission without the need for a special clutch.

[Means for Solving the Problems]

The characteristic configuration of the present invention is to disengage and operate all the friction clutches while maintaining the hydraulic pressure adjusting mechanism in a pressure adjusting state in which the clutch operating pressure is set to the set maximum value in the operating structure for traveling of the work vehicle described above. The first clutch while maintaining the hydraulic pressure adjusting mechanism in a clutch disengaged position, a first clutch engaged position for engaging and operating one of the friction clutches, and a pressure adjusting state in which the clutch engaged operating pressure is set to the set maximum value. The friction clutch operated to be engaged by the engaged position is switchably formed to a second clutch engaged position which is operated at a hydraulic pressure lower than that of the first clutch engaged position, and the clutch disengaged position and the first clutch engaged state. The manual valve for the clutch is provided in a state in which the second clutch engagement position exists between the positions. The action and effect are as follows.

[Work]

When the clutch manipulating valve is rapidly switched from the clutch disengaged position to the first clutch engaged position, the clutch manipulating valve will disengage the clutch while maintaining the hydraulic pressure adjustment mechanism in the pressure regulating state. One of the hydraulically operated friction clutches is rapidly engaged and operated from the disengaged state, and this clutch rapidly transmits power to the traveling device.

When the clutch manual operation valve is switched from the clutch disengaged position to the second clutch engaged position and is maintained, one of all hydraulically operated friction clutches is engaged and operated with a hydraulic pressure lower than the normal engaging pressure. A half clutch is transmitted to the traveling device.

〔The invention's effect〕

Because of the artificially operated valve for the clutch, it is originally intended to enable speed change and forward / reverse switching by operating the operating valve.The clutch is used for rapid transmission and half-clutch transmission, and the aircraft suddenly starts and slows down. It becomes possible to start and escape from a wetland, and it is possible to make a sudden start operation of the machine during excavator work to impact the bucket into the earth and sand, or to escape by yourself even in a wetland Structure of advantageous things is simple and cheap I got it.

〔Example〕

 Next, examples will be shown.

As shown in FIG. 2, the rotational output of the engine (E) is transmitted to the forward / reverse switching device (2) via the flywheel (1), and the rotational output of the forward / reverse switching device (2) is switched in four stages. It is transmitted to a traveling auxiliary transmission (4) capable of switching between two stages via a possible traveling main transmission (3), and
The rotation output of the auxiliary transmission (4) is transmitted to the rear wheel differential mechanism (5) and the front wheel transmission shaft (6), and the rotation output of the engine (E) is transmitted to the clutch (C). ) And the power transmission shaft (7), and the power transmission shaft (9) is directly connected to the power transmission shaft (9) that can be switched between two stages and is directly connected to the power transmission shaft (9). The transmission structure for traveling and working equipment is configured.

The forward / reverse switching device (2) is constructed as follows.

That is, as shown in FIG. 2 and FIG. 3, the forward transmission gear (1) meshed with the first gear (11) of the input cylinder shaft (10).
2) and a reverse transmission gear (15) which is interlocked with the second gear (13) of the input cylinder shaft (10) via the reverse rotation gear (14) and is attached to the output shaft (16) so as to be relatively rotatable, Output shaft (1
A multi-plate wet type forward friction clutch (FC) is provided between the clutch body (17) and the forward transmission gear (12) that are integrally rotatably attached to 6) so as to be operated by the first hydraulic piston (18). A multi-plate wet type reverse friction clutch (RC) is provided between the clutch body (17) and the reverse transmission gear (15) so as to be operated by the second hydraulic piston (19). And, a pair of piston chambers (20) formed by the clutch body (17) and internally provided with the first hydraulic piston (18) and the second hydraulic piston (19), respectively.
(21) is connected to _one forward / reverse switching valve (V ₁ ) as shown in FIG. 1 through an oil passage formed in the output shaft (16), the transmission case (22), etc. The forward / reverse switching valve (V ₁ ) is selectively supplied to the piston chambers (20) and (21) by supplying oil so that the first hydraulic piston (18) or the second hydraulic piston (19) is engaged. , The forward friction clutch (FC) and the reverse friction clutch (RC) are selectively operated to be operated.

That is, when the forward friction clutch (FC) is turned on and the reverse friction clutch (RC) is turned off by the switching operation of the forward / reverse switching valve (V ₁ ), the rotational force of the input cylinder shaft (10) is changed to the gear (11). ), (12) and the clutch body (17) to the output shaft (16) so that it is in the forward drive state, and the forward friction clutch (FC) is disengaged and the reverse friction clutch (RC) is engaged. When the input cylinder shaft (10) is operated in the reverse direction, it is in the reverse drive state so that the rotational force of the input cylinder shaft (10) is transmitted to the output shaft (16) via the gears (13), (14), (15) and the clutch body (17). It will be.

To be able to supply oil from the oil passage (23) connecting the forward-reverse switching valve (V ₁ ) and the hydraulic pump (P) to the oil passage (24) for lubricating the forward friction clutch (FC) and the reverse friction clutch (RC). The forward friction clutch (FC) includes a relief valve (25) connected to the connection oil passage (23) and a hydraulic cylinder (26) attached to the relief valve (25) so as to change and adjust the relief pressure of the relief valve (25). And a hydraulic pressure adjusting mechanism (M) for gradually increasing the operating pressure of the reverse friction clutch (RC) to a predetermined transmission high pressure value, and moving the operating oil passage (27) of the hydraulic cylinder (26) forward and backward. proceeds by connecting the switching valve (V _1), are coordinated to automatically operate Accordingly the switching operation to a hydraulic adjusting mechanism (M) of the forward-reverse switching valve (V _1). That is, when the forward / reverse switching valve (V ₁ ) is operated to the forward drive position (F) or the reverse drive position (R), the operation oil passage (27) is connected to the connection oil passage (23) and the hydraulic pump (P) is connected.
Is gradually supplied to the hydraulic cylinder (26) through the throttled portion (27a) of the operating oil passage (27), and the relief valve (25) is adjusted by the hydraulic cylinder (26) to gradually increase the relief pressure. From the hydraulic pump (P) to the piston chamber (2
The hydraulic pressure to 0) or (21) is gradually increased. Then, each time the forward / reverse switching valve (V ₁ ) is switched from _one of the forward drive position (F) and the reverse drive position (R) to the other and passes through the neutral position (N), the operating oil passage (27) causes the tank ( Connected to T), the hydraulic cylinder (26) passes through the portion with check valve (27b) of the operating oil passage (27) due to the elastic restoring force of the relief pressure setting spring (28) of the relief valve (25). Oil is quickly and quickly drained, and the relief pressure of the relief valve (25) is set to the value when the clutch engagement operation is completed from the high pressure value to the value when the clutch engagement operation is started in order to adjust the relief pressure drop by the hydraulic cylinder (26). It returns to the value.

Forward-reverse switching valve (V ₁₎ to connect clutch manual operation valve (V _2), the forward-reverse changeover valve (V ₁₎ a forward position (F) or reverse position the operating valve while maintaining the (R) By operating (V ₂ ), both the forward friction clutch (FC) and the reverse friction clutch (RC) can be turned off, and either clutch can be operated regardless of the presence of the hydraulic pressure adjustment mechanism (M). (FC) or (RC) can be operated by rapidly entering the set high pressure value for power transmission, or can be operated in the entry state at a pressure lower than this set high pressure value, and is rapidly transmitted to the traveling device so that the vehicle body starts suddenly. In addition, it is possible to transmit a half clutch to the traveling device so that the vehicle can escape from the wetland
A forward friction clutch (FC) and a reverse friction clutch (RC) are used as clutches for switching between the traveling main transmission (3) and the traveling auxiliary transmission (4). That is, the clutch manually operated valve (V ₂ ) is constructed as shown in FIG.

That is, the valve body (31) has a valve body (32), a first spring (33) that acts on one end side of the valve body (32), and two pieces that act on the other end side of the valve body (32). Second springs (34) and (35) of the valve body (31) and a spring receiver (36) acting on the side opposite to the valve body side of the second springs (34) and (35). It is installed throughout. The valve body (32) slides along the stopper / guide (37), and as shown in FIG. 5, the outer peripheral groove (38) shown in FIG. 7 has the first notch (39) and the valve seat portion. The piston chamber (20) communicates with the pump port (P ₂ ) through the circumferential groove (40) and the valve seat hole (41) and also communicates with the cylinder port (C) through the valve seat hole (42). ) Or (21) is connected to the forward / reverse switching valve (V ₁ ) at the oil supply position, as shown in FIG. 6, the first notch (39) is disengaged from the valve seat inner peripheral groove (40) and the outer peripheral groove is formed. (38) communicates with the cylinder port (C) and
The piston chamber (20) communicates with the tank port (t ₂ ) through the second notch (43) and the spring chamber (44) as shown in the figure.
Or, the drainage position where (21) is not connected to the forward / reverse switching valve (V ₁ ) but is connected to the tank (T), as shown in FIG. 4, the outer peripheral groove (38) Communicate with the cylinder port (C), the first notch (39) is disengaged from the inner circumferential groove (40) of the valve seat, and the second notch (43) is connected to the spring chamber (4
4) Remove the piston chamber (20) or (21) from the forward / reverse switching valve (V ₁ ) and the tank (T) so that the neutral position is switched to the neutral position. is there. Pressure oil from the piston chamber (20) or (21) that acts on the pressure receiving portions (46) and (47) provided inside the valve body, which communicates with the outer peripheral groove (38) through the through hole (45). The back pressure and the first spring (33) urge the valve body (32) to the oil discharge position, and the second springs (34) and (35) urge the valve body (32) to the oil supply position. In addition, as the clutch pedal (48) is oscillated, the spring receiver (36) causes the pedal return spring (49) to move to the second position.
The springs (34) and (35) are slidably adjusted to adjust the biasing force of the second springs (34) and (35).

More specifically, the pedal (49) is in the non-depressed position (ON).
, The spring receiver (36) is pushed for the pedal return spring (49) to increase and adjust the urging forces of the second springs (34) and (35) to the set maximum value.
The valve disc (3
2) is operated to the refueling position due to the second springs (34) and (35) to enable refueling from the forward / reverse switching valve (V ₁ ) to the piston chamber (20) or (21). When the clutch actuated operating pressure reaches the set maximum value as a result, the pressure oil for operating the hydraulic piston (18) or (19) to the clutch engaged position and the biasing force of the first spring (33) and the second spring (34) and The urging force of (35) balances the valve body (32) to the neutral position, and the clutch (FC) or (FR)
Thus, the first clutch engagement position (on ₁ ) is reached so as to operate the clutch in a completely engaged state. And pedal (4
When 8) is depressed to the maximum depressed position (OFF), the spring receiver (36) causes the second springs (34) and (35).
Is pushed out to the stroke end by adjusting the urging force of the second springs (34) and (35) to a set minimum value, and the valve body (32) drains oil due to the back pressure and the first spring (33). Position, the pump port side is closed and back pressure is applied to the forward / reverse switching valve (V ₁ ) while allowing pressure release of the piston chamber (20) or (21), and the hydraulic piston (18) or (19) The clutch disengagement position (off) is set so as to disengage the clutches (FC) and (RC) while maintaining the hydraulic pressure adjusting mechanism (M) in a pressure regulating state in which the clutch operating pressure is set to the set maximum value. Then, when the pedal (48) is depressed to an operating position between the non-depressed position (ON) and the maximum depressed position (OFF), the spring receiver (36) causes the pedal operation force and the second spring (34) and An intermediate mounting position is reached due to the balance with (35), and the urging forces of the second springs (34) and (35) are adjusted to an intermediate value between the set maximum value and the set minimum value, and the valve body (32) Is in the oil discharge position due to the back pressure and the first spring (33) and enables the pressure release of the piston chamber (20) or (21). With this pressure release, the back pressure and the first spring (33) are released. ) And the urging forces of the second springs (34) and (35) are balanced, the urging force of the second springs (34) and (35) adjusted so that the valve body (32) is in the neutral position. Maintain the clutch operating pressure at a value determined by the above, and set the clutch operating pressure to the set maximum value. The second clutch engaged position (on ₂ ) so that the clutch (FC) or (RC) is engaged at a hydraulic pressure lower than the set maximum value while maintaining the hydraulic pressure adjusting mechanism (M) in the regulated state.
It becomes.

Therefore, by depressing the pedal (48) to the maximum depressing position (OFF), operating the clutches (FC) and (RC) to the off position, and then returning the pedal (48) to the non-depressing position (ON), The hydraulic pressure adjusting mechanism (M) rapidly supplies the highest pressure oil pressure to the piston chamber (20) or (21), and the clutch (FC) or (RC) rapidly enters. Then push the pedal (48) to the maximum depression position (OF
By depressing to the operation position up to F), some pressure is released from the piston chamber (20) or (21), and the clutch (FC) or (RC) can be adjusted and maintained in a half-clutch state. is there.

As shown in FIG. 8, the forward / reverse switching valve (V ₁ ), the hydraulic pressure adjusting mechanism (M) and the clutch manually operated valve (V ₂ ) are provided on the vehicle body forming transmission case (22) on the oil passage forming plate (50). It is installed in one valve body (31) that is attached via.

An inner part (24a) of the lubricating oil passage (24) that passes through the inside of the transmission case (22) to the output shaft (16) is formed by a hole formed in the transmission case (22). A connecting portion (24b) between the case inner portion (24a) and the hydraulic pressure adjusting mechanism (M) in 24) is formed of a pipe. And
A rubber sleeve (52) fitted over the pipe and incorporated in the hole of the transmission case (22) allows the inner part of the case (24
There is a seal between a)) and the connection (24b).

[Another embodiment]

FIG. 9 shows another embodiment of the hydraulic pressure adjusting mechanism (M) and the clutch manually operated valve (V ₂ ), and the check portion (27a) of the operation oil passage (27) of the hydraulic pressure adjusting mechanism (M) and the non-return check. Valved part (27
By connecting b) to the forward / reverse switching valve (V ₁ ) separately, the hydraulic pressure adjusting mechanism (M) is linked to the forward / reverse switching valve (V ₁ ).

The artificially operated valve for the clutch (V ₂ ) is at the clutch disengagement position (of
When operated in f), the oil supply passage (53) for the forward / reverse switching valve (V ₁ ) is made to communicate with the tank (T) so that the clutches (FC) and (RC) are turned off. Then, when operated to the first clutch engaged position (on ₁ ),
By supplying the entire amount of oil from the forward / reverse switching valve (V ₁ ) to the oil supply passage (53), the clutch (FC) or (RC) is operated in the completely engaged state. When the second clutch engaged position (on ₂ ) or (on ₃ ) is operated, a part of the oil from the forward / reverse switching valve (V ₁ ) is fed to the lubricating oil passage (2
By supplying the rest to the oil supply passage (53) while supplying it to 4), the clutch (FC) or (RC) is operated with the hydraulic pressure lower than the set maximum value.

As shown in the above embodiment, two friction clutches (FC),
(RC) is provided so that the forward transmission state and the reverse transmission state are separately displayed, and alternatively, the two or more friction clutches are selectively operated. Thus, the present invention can be applied to a case in which the transmission state of one of a plurality of different speed stages is selectively displayed. Therefore, the forward friction clutch (FC) and the reverse friction clutch (RC) are referred to as friction clutches (FC) and (RC) that express the transmission state for traveling, and the forward / reverse switching valve (V ₁ ) is simply operated by the operating valve ( V ₁ ).

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of the operating structure for traveling of a work vehicle according to the present invention. FIG. 1 is a hydraulic circuit diagram, FIG. 2 is a transmission system diagram, and FIG.
FIG. 4 is a sectional view of a forward / reverse switching clutch, FIG. 4 is a sectional view of a clutch manually operated valve, FIGS. 5 and 6 are operation explanatory views of the clutch manually operated valve, FIG. 7 is a plan view of a valve body, and FIG. FIG. 8 is a partially cutaway plan view of the operation valve installation portion, and FIG. 9 is another embodiment hydraulic circuit diagram. (FC), (RC) …… Friction clutch, (V ₁ ) …… Operating valve,
(V ₂ ) …… Human operated valve for clutch, (M) …… Hydraulic control mechanism, (off) …… Clutch disengagement position, (on ₁ ) …… First
Clutch engagement position, (on ₂ ), (on ₃ ) ... 2nd clutch engagement position.

Claims (1)

[Claims] 1. A plurality of hydraulically-operated friction clutches (FC), (RC) for expressing a transmission state for traveling and one friction clutch (FC), (RC) for selectively entering and operating. An operating valve (V ₁ ) is installed and the friction clutches (FC), (R
Hydraulic adjusting mechanism (M) the operating valve to increase the incoming operating pressure of C) gradually (V ₁₎ of the operating valve in a state that operates automatically with the switching operation (V ₁₎ working vehicle which is linked to The operation structure for traveling, wherein all the friction clutches (FC), (RC) are operated while maintaining the hydraulic pressure adjusting mechanism (M) in a pressure adjusting state in which the clutch operating pressure is set to a maximum value. Clutch disengagement position (off), the friction clutch (F
C), the first clutch engaged position (on ₁ ) for operating one of (RC), and the hydraulic pressure adjusting mechanism (M) is maintained in a pressure adjusting state in which the clutch operating pressure is set to the set maximum value. Meanwhile, the friction clutch (FC or RC) that is operated to be engaged or disengaged by the first clutch engagement position (on ₁ ) is
Clutch engaging position (on ₁₎ the second clutch engaging position to operate enters at a lower hydraulic pressure according to (on _2), switching freely formed in (on _3), and said clutch disengaging position (of
f) and the second clutch engagement position (on ₁ )
An operating structure for traveling of a work vehicle that is provided with a clutch manually operated valve (V ₂ ) so that the clutch engagement positions (on ₂ ) and (on ₃ ) exist.