JPS6139145Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention has a fluid pressure operated piston that presses and engages each of a plurality of multi-plate transmission clutches for speed change, in a state where the piston is biased to return to the clutch disengagement position. The gear shift lever is provided with a control valve that is moved toward a clutch engagement position by fluid supply and that switches the operating state of each piston in accordance with the movement of a reciprocating valve body, and is reciprocally movable. The present invention relates to a hydraulic transmission for a working vehicle, in which the valve body is interlocked and connected to the valve body by a mechanical interlocking mechanism so that the valve body can be moved and operated.

The above-mentioned fluid pressure type transmission can be applied to the traveling speed of various work vehicles such as combine harvesters, tractors, transport vehicles, and construction machinery, and to change the operating speed of various work devices equipped with it. There is an inconvenience that a no-output state is brought about, and especially when used for traveling speed change, there is also an inconvenience that the aircraft's movement is temporarily stopped.

More specifically, in order to avoid two shift states occurring at the same time, fluid is supplied to the piston to which fluid should be supplied next while the shift lever is being moved from the shift operating position to the adjacent shift position. Fluid previously supplied to unnecessary pistons will be drained, resulting in an unnecessary shift neutral condition. In order to avoid this, it is only necessary to quickly move the gear shift lever from one gear shift position to the adjacent gear shift position to suppress the time during which the unnecessary gear shift neutral state is brought about to a very short time. In practice, it is difficult to perform such a lever operation, and the above-mentioned inconveniences arise.

An object of the present invention is to avoid an unnecessary no-output state during gear shifting while suppressing complication of lever operation.

The characteristic configuration of the present invention is that during the mechanical interlocking mechanism between the speed change lever and the valve body, the speed change lever is allowed to move in advance with respect to the valve body, and the elastic force acting on the valve body is accordingly reduced. a locking mechanism that incorporates an elastic mechanism for accumulating and that locks a portion of the interlocking mechanism closer to the valve body than the elastic mechanism so as to maintain the valve body in the gear shift position; The locking state is maintained against the accumulated elastic force during the initial movement to the adjacent shift operation position, and the locking state is switched to the unlocked state during the final movement.

In other words, during the initial movement of the shift lever from the shift position to the adjacent shift operation position, the elastic force acting on the valve body is accumulated in the elastic mechanism without moving the valve body, and the final movement of the shift lever is At times, the valve element can be moved at high speed from one gear shift position to the adjacent gear shift position by working together with the accumulated elastic force of the elastic mechanism, so that the gear shift lever is not moved quickly. In both cases, the valve body can be moved at high speed from one gear shift position to the next gear shift position to avoid unnecessary no-output conditions during gear shifts, making the work even more convenient. This led to the development of a hydraulic transmission system for cars.

Embodiments of the present invention will be described below based on the drawings.

As shown in FIG. 1, left and right running crawlers 1a,
1b, the front part of this machine equipped with a threshing device 2, etc. is equipped with a stem culm pulling device 3, a cutting blade 4 for cutting the stem culm stock base, a device 5 for conveying the harvested stem culm to the rear threshing device 2, etc. The reaping processing section is connected, and as the aircraft advances,
The system is configured to automatically and continuously perform the operations of lifting and reaping the stem culms planted in the field and sequentially threshing the harvested stem culms.

As shown in FIG. 2, an input shaft 7, a first transmission shaft 8, a second transmission shaft 9, and an output shaft 10, through which the engine output is transmitted by a belt, are connected to a traveling transmission case 6 installed in the machine. A small diameter first transmission gear 7a and a large diameter second transmission gear 7b are fixed to the input shaft 7, and the first transmission shaft 8
A first forward speed transmission gear 8a that is always in mesh with the first transmission gear 7a and a third forward speed transmission gear 8b that is always in mesh with the second transmission gear 7b are freely rotatably supported, and
The third transmission gear 8c is fixed to the second transmission shaft 9, and the reverse gear 9 is always engaged with the transmission gear 8a for the first forward speed.
a and the second forward speed gear 9b that is always engaged with the second transmission gear 7b, and the fourth transmission gear 9c.
is fixed to the output shaft 10, and a third transmission gear 8c is attached to the output shaft 10.
and a fifth transmission gear 10a that is always engaged with the fourth transmission gear 9c, and a first, second, and third forward gears, and a first gear that supports each of the forward gears 8a, 2nd gear, 3rd gear, and reverse gear 8a.
Multi-plate gear shifting friction clutches A, B, C, and D are provided between the second transmission shafts 8 and 9, and a hydraulically operated piston Sa that presses and engages each clutch A separately. , Sb, Sc, and Sd are provided in a state where they are biased to return to the clutch disengaged operating position and are moved toward the clutch engaged operating position by oil supply, and each piston Sa... By operating each separately, the traveling speed can be increased by 3.
It is configured so that it can be switched to one gear and one reverse gear.

Further, a reaping section driving pulley 11 is attached to the outer end of the case of the output shaft 10 via a one-way rotating clutch 12 that prevents the pulley 11 from being rotated in the reverse transmission state. It is constructed so that the operating speed of the vehicle can be changed in synchronization with the traveling speed.

Further, a sub-transmission gear 13 having three large, medium, and small gear portions is slidably connected to the output shaft 10 by a spline, and the sub-transmission transmission shaft 14 is provided with a spline connection.
Fixing three gears 14a, 14b, 14c that alternatively mesh with the sub-transmission gear 13,
The rotational speed of the output shaft 10 is configured to be variable between a high-speed transmission state for driving on the road and a two-speed transmission state of high and low speed for reaping work.

Further, the steering clutch shaft 15 supports a transmission gear 15a which is in constant engagement with a small-diameter gear 14c for auxiliary transmission, and is capable of engaging and disengaging from the sides of the transmission gear 15a, and is gear-interlocked with the left and right axles 16a, 16b. The left and right clutch gears 17a and 17b are spline-connected, so that the vehicle can be steered by sliding operation of the left and right clutch gears 17a and 17b.

As shown in FIG. 3, each of the hydraulic cylinders
A rotary type control valve 18 is provided to switch the operating state of Sa..., and an accumulator 19 that accumulates a portion of the oil supplied from the control valve 18 to the cylinder when the clutch is engaged is operated only in the neutral shift state. The accumulated oil is provided in a state to be discharged into the tank 20, so that the piston operating speed at the initial stage of the clutch engagement operation can be made low when switching from the neutral shift state to the output shift state, and the output The structure is such that the piston operating speed can be made high when switching from the power transmission state to the output transmission state.

As shown in FIG. 3, a throttle valve 22 is provided to reduce the supply speed of oil supplied from the hydraulic pump 21 to the control valve 18, thereby suppressing each piston Sa from being operated at an unnecessarily high speed. I have made it possible. Further, a main relief valve 23 is provided which determines the maximum pressure of oil supplied from the pump 21 to each piston Sa, and drained oil from this valve 23 is supplied to each clutch A for cooling. A sub-relief valve 25 is further provided to determine the maximum pressure of the cooling oil supply pressure.

As shown in FIGS. 4 to 9, the control valve 1
The rotary type valve element 18A of No. 8 is rotatably housed in the valve casing 26 attached to the upper part of the traveling transmission case 6 with one end protruding. , an intermediate swing link 28 to which the valve actuator operating arm 27 is attached so as to be freely rotatable, and which locks and swings the arm 27;
is pivotally supported on a support frame 29 projecting upward from the valve casing 26 so as to be swingable back and forth, and a long hole 31 is formed in the arm 27 to receive a locked pin 30 fixed thereto. A plate spring 33 provided at the base of the gear shift lever 32 and bolted to the base of the shift lever 32 is bolted to the swing link 28, and the lever locking frame 34 resists the engagement biasing force of the plate spring 33. The lever 34 is disposed in such a manner that it is unlocked by horizontal swinging, and then the shift lever 32 is moved from the neutral gear shift operating position N toward the front side to the forward first gear operating position F ₁ , As the valve body 18A is moved to the operating position F ₂ for forward 2nd gear and the operating position F ₃ for 3rd forward gear, the valve body 18A is rotated to perform forward gear shifting, and the shift lever 32 is moved to the operating position for neutral gear shifting. As the valve body 1 is moved from N toward the rear and moved to the reverse operation position R, the valve body 1
8A is rotated to perform a reverse gear change.

The leaf spring 33 is bent in a step-like manner when viewed in the front-rear direction of the aircraft, so that it can be elastically deformed in the moving direction of the gear shift lever 32.
This constitutes an elastic mechanism that allows the speed change lever 32 to move in advance relative to the valve body 18A and accumulates the elastic force acting on the valve body accordingly. Further, a ball 35 is engaged with the valve operating arm 27 in a state where it is projected and biased by a spring 36, and the ball 35 is inserted into the valve body 18A at a position corresponding to each of the plurality of rotational positions for speed change. A plurality of recesses 3 that are removably engaged with each other.
7... are formed on the support frame 29, and the valve body 18
A locking mechanism is configured to lock the valve operating arm 27 so as to maintain the gear shifter A in the gear shifting position.
This locking mechanism maintains the locking state against the accumulated elastic force during the initial movement of the shift lever 32 from the shift operation position to the adjacent shift operation position, and maintains the locking state during the final movement. The biasing force of the spring 36 and the shape of the recess 37 are determined so that the spring 36 can be switched to the unlocked state at any time,
The valve body 18A is configured to rotate at a high speed in cooperation with the accumulated elastic force during the final movement and depression of the speed change lever 32.

Also, the depth of the recess 37a corresponding to the reverse gear change is made sufficiently shallower than the other recesses 37, so that when operating from the reverse gear change state to the neutral shift state, the accumulated elasticity is reduced. The valve body 18A is rotatably moved without using force. In short, when operating from a reverse shift state to a neutral shift state, the valve body 18A is moved together with the shift lever 32 to avoid an unnecessarily long output state, thereby improving safety. It is structured as follows.

The present invention may be implemented pneumatically.

Further, as the control valve 18, a spool type valve having a sliding valve body may be used.

Further, as the mechanical interlocking mechanism that interlocks and connects the speed change lever 32 and the valve body 18A, various types such as those using wires can be used.

Further, the elastic mechanism 33 may be constructed using a tension spring, a pressure spring, or the like.

[Brief explanation of drawings]

Fig. 1 is a side view of the combine, Fig. 2 is a schematic diagram of the transmission structure, Fig. 3 is a hydraulic circuit diagram, Fig. 4 is a rear view of the gear lever mounting part, Fig. 5 is a side view of the same part, Fig. 6 is a cutaway rear view showing the attachment part of the valve actuation arm, Fig. 7 is a side view of the same part, Fig. 8 is a plan view of the lever locking frame, and Fig. 9 shows the ball engagement state. FIG. 18... Control valve, 18A... Valve body, 32... Speed change lever, 33... Elastic mechanism, 35, 36, 37
...Locking mechanism, A...Multi-plate power transmission clutch, Sa...
...Fluid pressure operated piston.

Claims (1)

[Scope of utility model registration request] A fluid pressure operated piston that individually presses and engages each of a plurality of multi-plate transmission clutches A for speed change.
Sa... is provided in a state where it is urged to return to the clutch disengaged operating position and is moved towards the clutch engaged operating position by fluid supply, and as the valve body 18A, which is reciprocally movable, moves. A control valve 18 is provided for switching the operating state of each piston Sa, and a reciprocating shift lever 32 is interlocked and connected to the valve body 18A by a mechanical interlocking mechanism so that it can be moved. This is a hydraulic transmission system for a working vehicle, in which the interlocking mechanism allows the speed change lever 32 to move in advance with respect to the valve body 18A, and accordingly reduces the elastic force acting on the valve body. Incorporating an elastic mechanism 33 for accumulation,
locking mechanisms 35, 36, 37 that lock a portion of the interlocking mechanism closer to the valve body than the elastic mechanism 33 to maintain the valve body 18A in the gear shifting position;
When the shift lever 32 is moved from a shift operation position to an adjacent shift operation position, the locked state is maintained against the accumulated elastic force during the initial movement, and the locked state is maintained during the final shift. A hydraulic transmission for a work vehicle, characterized in that the transmission is configured to be switched to