JPS6338577B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves fitting a cylindrical rotary valve body into a valve body, and by rotating the cylindrical rotary valve body, a plurality of ports formed in the valve body can be selectively connected to oil supply ports and exhaust ports. The present invention relates to a speed change operation valve for a power transmission configured to be connected in communication with an oil port.

The above-mentioned speed change operation valve for power transmission operates by rotating a cylindrical rotary valve body.
A combination is selected in which a plurality of ports formed in the valve box are connected to an oil supply port or an oil drain port so that a series of gear shifting operations can be carried out smoothly. As such, an annular oil supply side groove 28 which is always in communication with the pump port formed in the valve body and an annular oil drain groove 31' which is always in communication with the drain port are arranged in parallel in the axial direction on the circumferential surface of the rotary valve body 27. , an annular groove 28 on the oil supply side and an annular groove 31' on the oil drain side.
In addition to creating an uneven shape at the boundary between the
A plurality of ports are formed in a line on the valve box side corresponding to this boundary at appropriate intervals, and each of the plurality of ports is communicated with an oil supply port or an oil drain port by rotating the rotary valve body. Since we wanted to configure the structure so that the combination of
31' are arranged in parallel, the length of the rotary valve body 27 in the axial direction becomes long, and when a large number of ports are formed at predetermined intervals as in a power transmission speed control valve, the rotation In order to increase the circumferential length of the valve body 27, the diameter of the rotary valve body 27 also increases, resulting in a problem that the entire valve becomes larger.

Therefore, in order to increase the diameter of the rotary valve body in the above problem, it is conceivable to provide multiple ports formed in the valve body in multiple rows, but in this case, the oil supply formed in the rotary valve body A new problem arises where the boundary between the side annular groove and the oil drain side annular groove has a plurality of shapes.

The present invention has been made in view of the above circumstances, and although it is a valve equipped with a large number of ports,
The purpose is to simplify the structure and make it as small as possible by devising the shape of the rotary valve body.

The characteristic structure of the speed change operation valve for a power transmission according to the present invention, which has been made to achieve the above object, is that both left and right end surfaces are formed into uneven surfaces partially protruding in the axial direction along the circumferential direction. and an annular groove along the circumferential surface, and a cylindrical rotary valve body having a concave portion continuous with the annular groove formed on the circumferential surface of the protruding portions of the left and right end surfaces is fitted into the valve box, and the valve body is fitted into the valve box. The pump port of the box is always communicated with the annular groove, the recess is configured as an oil supply recess, and the recess is formed along the circumferential direction by being sandwiched between the protrusions on both left and right end surfaces of the rotary valve body. The recess is configured as an oil drain recess by being in constant communication with the drain port of the valve box, and the oil supply recesses on both sides of the annular groove are positioned corresponding to the oil drain recess to connect the plurality of ports to the oil drain recess. The present invention is formed in a valve box, and is configured to selectively connect the plurality of ports to the oil supply recess and the oil drain recess by rotating the rotary valve body. It has the following effects.

That is, instead of arranging the oil supply side annular groove and the oil drain side annular groove side by side on the circumferential surface of the rotary valve body as in the conventional case,
Both left and right end surfaces of the rotary valve body are formed into uneven surfaces, and almost the entire circumferential surface of the protrusion is formed into a recess for oil supply,
Since the recesses along the circumferential direction of the left and right end surfaces of the rotary valve body are formed in the oil drainage recess, the axial length of the rotary valve body can be shortened.

In order to reduce the diameter of the rotary valve body, instead of simply dividing the large number of ports into two rows and forming them in the valve box, the recesses on both the left and right end surfaces of the rotary valve body are formed as oil drainage recesses. However, since they are formed in two rows along the left and right oil supply recesses and oil drain recesses,
The shape of the boundary part is not complicated as in the conventional case, and the structure can be simplified.

Therefore, according to the present invention, it is possible to reduce the size of the power transmission speed change operation valve without complicating the structure.

Incidentally, in order to shorten the axial length of the rotary valve body, it is possible to connect the annular groove to the drain port at all times and form a common oil passage on the oil supply side on the end face of the valve body. Due to the change in the arrangement of the ports, the disadvantage is that the oil passage configuration of the piping connecting the pump ports becomes complicated.

According to the present invention, by forming the oil collection passage on the end face of the rotary valve body, when the valve box is attached to the wall surface of the transmission case which is also used as a hydraulic oil tank, as is conventionally done, the oil collection passage can be formed on the end face of the rotary valve body. Waste oil collected on the road,
The oil return to the transmission case can be returned directly to the transmission case without complicating the structure, and compared to forming the oil supply side common oil passage on the end face of the rotary valve body, this method has the advantage of being advantageous in terms of manufacturing. be.

Next, embodiments of the present invention will be described in detail based on illustrative drawings.

As shown in FIG. 1, power from the engine E is transmitted to the main transmission 1, hydraulic multi-disc clutch 2, auxiliary transmission 3, and super-deceleration switching device 4 in that order, and the super-deceleration switching device The power taken out from device 4,
A pair of left and right rear wheels 6 via a rear wheel differential device 5
In addition, the power is transmitted to a pair of left and right steering front wheels 9 via a transmission shaft 7 and a front wheel differential device 8. Then, the power branched from the transmission upper side of the main transmission 1 is transferred to the power extraction transmission 1.
0 and a hydraulic multi-plate clutch 11 to transmit the power to the working machine drive power take-off shaft 12;
It constitutes a drive device for a working vehicle such as a wheel-drive tractor.

As shown in FIGS. 1 and 2, each transmission device 1, 3, 4, 10 has a neutral position N
9 rotary positions including (N, F ₁ ~ F ₃ )
The traveling system speed change valve V ₁ configured as a switching valve allows
The two sets of shift operation actuators 13a, 13b in the main transmission mechanism 1 and the high/low speed switching actuator 14 in the auxiliary transmission 3 are operated integrally, and the 4-speed shift in the main transmission 1 and the 4-speed shift in the auxiliary transmission 3 are performed. The actuator 15 for forward/reverse switching in the sub-transmission device ₃ is configured to provide a two-speed shift and is configured as a sliding 3-position (N, F, R) switching valve. The configuration is such that an 8-speed transmission state can be obtained in each of the forward and forward directions.

The super deceleration switching device 4 is operated by the mechanically operated shift device 16 to switch between the normal deceleration state and the super deceleration state, and
Similarly, a mechanically operated shift device 17 is configured to continuously operate power transmission to the front wheel drive transmission shaft 7 to switch between a two-wheel drive state and a four-wheel drive state.

In addition, the power take-off system speed change valve _V3 , which is configured as a rotary type 5-position n, _f1 to _f4 switching valve including the neutral position n, controls two sets of speed change operation actuators 18a in the power take-off transmission 10. ,18
b is integrally operated to perform a four-speed power extraction system.

In addition, P in the figure is an operating pressure oil supply pump directly connected to the input shaft _S1 of the transmission case M.

When operating each of the clutches 2 and 11, the second
As shown in the figure, each actuator 13a,
13b, 14, 15, 18a, 18b in a state where the plunger 19 is also used as a sliding spool, and the actuators 13a, 13b, 1
six three-position switching valves x 1 to x 6 that block the flow of pressure oil from the corresponding valves V ₁ , V ₂ , and V ₃ only when 4, 15, 18 a, _{and 18 b} are in the neutral position;
Five 2-position switching valves y ₂ - y 5 each operated by pilot pressure from the 3 _- position switching valves x ₁ - _{x 6}
Of these, three drive system hydraulic clutches y ₂ , y ₃ , y ₄ operate the drive system hydraulic clutch 2, two power take-off system hydraulic clutches y ₅ , y ₆ operate the power take-off system hydraulic clutch 11, and each valve V ₁ ,V ₂ ,
Each gear is configured to operate automatically in conjunction with the _V3 's gear change operation.

In addition, 20 in the figure is a relief valve 2 for the pump P.
This is a lubricating oil supply path for the clutches 2 and 11 which is also used as one circuit.

As shown in FIG. 4, the actuators 13a and 1 for both the transmission rotary valves V ₁ and V ₃ , the main transmission 1 and the power extraction transmission 10
3b, 18a, 18b and the two-position switching valves y ₃ , y ₄ , y ₅ , y ₆ corresponding to the actuators 13a, 13b, 18a, 18b are installed inside the main transmission 1 and the power extraction transmission 10. Front piping block attached to the side wall of the transmission case M
Each actuator 13a, 13b,
Shift forks 22 for gear change operation connected to 18a and 18b are centrally arranged in such a manner that they penetrate through block Ua and protrude into transmission case M, and
The forward/reverse switching valve V ₂ , two sets of actuators 14 and 15 for the auxiliary transmission 3, and one corresponding to one of the actuators 14
Two-position switching valves _y2 are centrally arranged on the outer surface of the rear piping block Ub attached to the side wall of the transmission case M in the interior part of the sub-transmission device 3, in the same manner as on the front piping block Ua side. . And oil passages bored in the piping blocks Ua and Ub before and after them, and
An oil passage bored into the wall of the mission case M that communicates with some of these oil passages allows operation devices such as valves, actuators, and switching valves, and pump P , both clutches 2,
11 are connected to each other in communication to form an operating hydraulic circuit as described above.

The traveling speed change rotary valve _V1 will be explained in more detail with reference to FIGS. 4 to 7.

Nine oil passages 24, 24a are drilled in the cylindrical spool case 23, and the spool case 23 is attached to the outer surface of the front piping block Ua. , nine ports 25 opened thereto and each oil passage 24, 24.
The oil passages 2 are installed in such a manner that they are connected in communication with each other, and receive pressure oil supply from the pump P.
The opening on the inner circumferential surface side of the spool case 23 of 4a (that is, the pump port a) is arranged at the center in the axial direction of the spool case 23, and the opening on the inner circumferential surface side of the other eight spool case 23 (b to i) is arranged at the center of the spool case 23 in the axial direction. Six of them are located outside in the axial direction of the spool case 23, and
The remaining two are juxtaposed on the inside in the circumferential direction of the spool case 23, respectively. Then, the spool case 2 is connected integrally to the valve rotation operation shaft 26.
Rotary spool 27 rotatably fitted into 3
An annular groove 28 is bored on the outer circumferential surface of the pump port a, and as the spool 27 rotates, the annular groove 28 and the other eight oil supply ports b are formed.
A plurality of oil supply recesses 29 for selectively communicating with appropriate ones of ~i are formed on the outer circumferential surface of the spool 27 on both sides of the annular groove 28, and are arranged in the circumferential direction of the spool 27. The two sets of actuators 13a and 13b for the main transmission 1 and the high/low speed switching actuator 14 are configured to be integrally operated by selectively supplying pressurized oil to each oil supply port b to i through a 27-turn switching operation. .

Note that the symbols for the pump port a and the eight oil supply ports b to i in FIG. 6 correspond to the symbols a to i in FIG. 3, which is a partially enlarged view of FIG. 2.

Ports b to i other than the oil supply ports b to i that received pressure oil supply by the rotation switching operation of the spool 27
In order to return the return oil to the transmission case M, which also serves as a hydraulic oil tank, the return oil recesses 30a and 30b are formed on the outer peripheral surface of the spool 27.
are formed between each of the oil supply recesses 29 in the circumferential direction of the spool 27, and
An oil collecting recess 31a communicating with all of the return oil recesses 30a located on the axially outer side with respect to the annular groove 28 is located at the center of the outer end surface of the spool 27, and a return oil recess 30b located on the inner side. Oil collection recesses 31b communicating with all of the spools 27 are formed at the center of the inner end surface of the spools 27, respectively. The return oil collected in the inner oil collecting recess 31b is communicated with the outer oil collecting recess 31a via the oil groove 26a formed on the circumferential surface of the rotary operation shaft 26, and the return oil is communicated with the outer oil collecting recess 31a. The collected return oil is transferred to the space inside the cover 32 that covers the entire front piping block Ua.
The liquid is directly discharged from the outer end opening 23a of the spool case 23, and is configured to flow back into the mission case M through a hole 33 formed in the piping block Ua to pass through the shift fork 22.

34 in the figure is a ball day tent that positions the rotational operation position of the spool 27 by selective elastic engagement with a plurality of holes 35a formed in a disk-shaped member 35 fixed to the rotational operation shaft 26. It is.

Further, the specific shape of the oil collection recess 31 disposed on the end face of the rotary spool 27 can be changed in various configurations, and these are collectively referred to as the oil collection path 31.

Furthermore, the specific reflux structure for communicating the return oil collected in the oil collection path 31 to the hydraulic oil tank can be modified in various ways, and the openings for the oil collection path 31 in the reflux structure are collectively referred to as It is called a drain port 23a.

The present invention is directed to a speed change operation valve in various power transmissions such as those for traveling speed change and power extraction shaft speed change.

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 illustrate embodiments and conventional examples of the speed change operation valve for power transmission according to the present invention,
Fig. 1 is a schematic overall plan view showing the drive structure, Fig. 2 is a hydraulic circuit diagram, Fig. 3 is a partially cutaway side view showing the arrangement structure of the operating device, and Fig. 4 is a diagram of the driving speed change valve in Fig. 2. A schematic enlarged view showing the port, FIG. 5 is an exploded perspective view of the traveling speed change valve, FIG. 6 is an exploded view of the rotary valve body, and FIG. 7 is a longitudinal sectional view of the traveling valve.
FIG. 8 is a perspective view of a rotary valve body showing a conventional example. 23...Valve box, 23a...Drain port, 2
7... Rotating valve body, 28... Annular groove, 29... Oil supply recess, 30a, 30b... Oil draining recess, 31...
...Oil collection path, a...pump port, b-i...supply/discharge port.

Claims (1)

[Claims] 1. Both left and right end surfaces are formed into uneven surfaces by partially projecting in the axial direction along the circumferential direction, and an annular groove 28 along the circumferential surface, and the projecting portions of the left and right end surfaces are provided with the A cylindrical rotary valve body 27 having a recess 29 that is continuous with the annular groove 28 is fitted into the valve box 23, and the pump port a of the valve box 23 is constantly communicated with the annular groove 28, so that the recess 29 is connected to the annular groove 28. recesses 30a and 30b formed along the circumferential direction and sandwiched by the protrusions on both left and right end surfaces of the rotary valve body 27 are always communicated with the drain port 23a of the valve body 23. The recess 30
a, 30b are configured as oil draining recesses 30a, 30b, and are positioned correspondingly to the oil supply recess 29 and oil draining recesses 30a, 30b on both sides of the annular groove 28, and the plurality of ports b to i are configured as the oil draining recesses 30a, 30b. It is formed in the valve box 23, and by rotating the rotary valve body 27, the plurality of ports b to i are selectively connected to the oil supply recess 29.
and the oil drainage recesses 30a and 30b.