JP3558374B2 - Valve system - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a valve system for controlling a power shift transmission of a tractor, for example.
[0002]
[Prior art]
In the tractor, the power shift transmission has a forward / reverse switching mechanism serving as a main clutch, a main transmission mechanism, an auxiliary transmission mechanism, a front-wheel equal-speed switching mechanism, and the like, and also has a differential lock mechanism and the like. Can be switched using a hydraulic clutch, a cylinder or the like.
[0003]
The valves that control these many hydraulic clutches, cylinders, etc. are centrally located at one location to facilitate maintenance and shorten piping from the hydraulic pump. The valves are centrally located on the outer surface of a cover mounted to close the opening.
As this type of valve, a solenoid valve is used, but the type that directly controls large hydraulic pressure becomes large, and the type that uses pilot hydraulic pressure to control the control valve indirectly becomes small. It is known that a device utilizing a pilot valve is preferable in a device having a concentrated arrangement.
[0004]
[Problems to be solved by the invention]
In the prior art pilot control valve, the control valve and the pilot valve are independent and connected by a long oil passage, and have low responsiveness due to oil leakage or the like. Are large, costly and the piping is cumbersome.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to arrange a control valve and a pilot valve in close proximity to a spool hole formed in a valve body, thereby achieving high responsiveness, enabling small-sized and inexpensive manufacture.
[0006]
[Means for Solving the Problems]
A first specific means for solving the problem in the present invention is a valve in which a spool 13 for a control valve B for controlling supply of hydraulic oil to an actuator A is inserted into a spool hole 12 formed in a valve body 11.
A pilot oil path P for supplying pilot oil for sliding the spool 13 is connected to the spool end of the spool hole 12, and a pilot valve C for controlling the pilot oil path P is arranged to face the spool 13. It is.
[0007]
A second specific means for solving the problem in the present invention is a valve in which a spool 13 for a control valve B for controlling supply of hydraulic oil to an actuator A is inserted into a spool hole 12 formed in a valve body 11. ,
A pilot oil passage P for supplying pilot oil for sliding the spool 13 is connected to the spool end of the spool hole 12, and a pilot valve C for controlling the pilot oil passage P is disposed to face the spool 13. The set of B and the pilot valve C are symmetrically arranged concentrically within the valve body 11 with the partition wall 11a interposed therebetween.
[0008]
Further, a third specific means for solving the problem in the present invention is that, in addition to the first or second specific means, a valve support 14 is fixed to an end of a spool hole 12 of a valve body 11, The tip of the valve support 14 abuts on the end of the spool 13 to form an oil passage 14a in communication with the pilot oil passage P. The oil passage 14a is moved by the solenoid 16 to the oil passage 14a. That is, a valve element 17 for opening and closing 14a is arranged.
[0009]
[Action]
In a spool hole 12 formed in the inner valve body 11, a spool 13 constituting a control valve B and a pilot valve C are disposed so as to face the spool 13. When the pilot valve C controls the pilot oil passage P, The pilot pressure is applied to the end of the spool 13 and slides against the spring 30 to control the control valve B.
[0010]
Spool holes 12 are symmetrically arranged in the inner valve body 11 with a partition wall 11a interposed therebetween, and a set of a control valve B and a pilot valve C is formed back to back, so that the occupied area is further reduced.
The position of the valve support 14 fixed to the end of the spool hole 12 of the inner valve body 11 can be regulated by contacting the end of the spool 13, and an oil passage formed in the valve support 14 is formed. At 14a, the pilot oil when the pilot pressure is not applied to the spool 13 is drained.
[0011]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 11, reference numeral 2 denotes a transmission case in which a transmission of a tractor is built, and an inspection opening 3 is formed on an upper surface, and a cover 4 for closing the opening 3 so as to be able to open and close is attached. An interior valve unit 5 is mounted on the inner surface of the cover 4 via a separate plate 8, and an exterior valve unit 6 is mounted on the outer surface, respectively, to constitute a valve system.
[0012]
As shown in FIG. 11, this valve system controls almost all actuators necessary for traveling of the tractor. The actuators include actuators AF and AR of a forward / reverse switching mechanism, and actuators A1 of a main speed change mechanism. -A4, actuators AL and AH of the auxiliary transmission mechanism, actuators AJ and AG of the front and rear wheel differential lock mechanism, and actuators AD and AE of the front-wheel equal-speed switching mechanism.
[0013]
The actuator A of each of these mechanisms is a hydraulic clutch that couples a rotating shaft and a transmission gear, a hydraulic cylinder that engages a differential lock body with a differential gear, and the like, and is a hydraulic cylinder that moves a shifter engaged with the transmission gear. Is also good.
As shown in FIGS. 2, 3 to 7, and 9, the exterior valve unit 6 includes a main clutch control valve BM that supplies pressure oil to actuators AF and AR of a forward / reverse switching mechanism to an outer valve body 21; Control valves BL and BH for controlling the actuators AL and AH, and pressure detection switches RM, RL and BH communicating with these control valves B. The control valves BM, BL, and BH use an electromagnetic proportional valve, and are larger than a control valve B for pilot control described later.
[0014]
K is a supply oil passage for supplying pressure oil connected to the hydraulic pump 7, formed through the inside of the outer valve body 21 and communicating with the control valves BM, BL and BH. The flow holes K1 and K2 are branched.
The outer valve body 21 has actuator operating oil passages SJ, SG, SD for supplying actuator operating oil to the actuators AJ and AG of the front and rear wheel differential lock mechanism and the actuators AD and AE of the front wheel constant speed switching mechanism. Connection tools 22J, 22G, 22D, and 22E that form the SE are provided.
[0015]
Eight outlet holes QF, QR, Q1 to Q4, QL and QH are formed in the cover 4 to allow the actuator hydraulic oil to flow through the wall, and the outlet holes QF, QR, Q1 to QH are formed at one end on the inner surface side. Connector connection ports NF, NR, N1 to N4, NL for connecting Q4, QL, and QH to actuators AF and AR of the forward / reverse switching mechanism, actuators A1 to A4 of the main transmission mechanism, and actuators AL and AH of the auxiliary transmission mechanism, respectively. , NH are formed, and pressure detection switches R1 to R4 are provided on the outer surface of the cover 4 so as to communicate with the extraction holes Q1 to Q4 for the actuators A1 to A4.
[0016]
The pressure detection switches RM, RL, BH, R1 to R4 are provided for detecting the pressure of the corresponding control valve B and controlling the operation timing in sequence.
A pair of left and right supply oil grooves 23 communicating with the communication hole K2 and a pair of left and right pilot oil grooves 24 communicating with the communication hole K1 on both left and right sides are formed on the joint surface (lower surface) of the cover 4 facing the separate plate 8. Are formed long, and a pressure reducing valve 25 is provided in the flow hole K1 to generate pilot oil from the supplied oil. The left and right supply oil grooves 23 and the left and right pilot oil grooves 24 communicate with each other on the left and right.
[0017]
1 and 7 to 10, the interior valve unit 5 includes ten sets of valves in which a control valve B and a pilot valve C are combined. In the inner valve body 11, spool holes 12 are formed concentrically with a central partition wall 11a interposed therebetween, and the spool holes 12 are arranged in five rows.
The control valves BF and BR and the pilot valves CF and CR are for a forward / reverse switching mechanism, the control valves B1 to B4 and the pilot valves C1 to C4 are for a main transmission mechanism, and the control valves BL and BH and the pilot valves CL and CH are an auxiliary transmission mechanism. Respectively.
[0018]
The inner valve body 11 is formed with a supply oil chamber α, a hydraulic oil chamber β, and a drain oil chamber γ facing each spool hole 12. The sliding of the spool 13 causes the hydraulic oil chamber β to move. The supply oil chamber α and the drain oil chamber γ on both sides are selectively communicated with each other so that the supply of hydraulic oil to the actuator A can be controlled.
Each supply oil chamber α communicates with the supply oil groove 23 through an oil hole 35 of the separate plate 8. The supply oil chamber α for the control valves BF and BR of the forward / reverse switching mechanism is provided in the inner valve body 11. The communication holes 36 communicate with each other.
[0019]
The hydraulic oil chambers β of the control valves BF and BR of the forward / reverse switching mechanism and the control valves B1 to B4 of the main speed change mechanism are oil grooves formed on the joint surface side of each of the separate plates 8 of the inner valve body 11 and the outer valve body 21. In addition, it communicates with the outlet holes QF, QR, Q1 to Q4 in the cover 4 through hydraulic oil holes TF, TR, T1 to T4 formed in the separate plate 8. One of the control valves BL and BH of the auxiliary transmission mechanism is taken out through the oil groove 37 of the outer valve body 21, and the other is taken out through the hole of the separate plate 8 and the oil groove 38 of the inner valve body 11. Is in communication with
[0020]
Hydraulic oil chambers β of the control valves BJ and BG of the front and rear wheel differential lock mechanisms and the BD and BE of the front-wheel equal-speed switching mechanism are provided with oil grooves in the inner valve body 11 and hydraulic oil holes TJ, TG and TD formed in the separate plate 8. , TE, cover 4, and four holes 27 of outer valve body 21 and are connected to connectors 22J, 22G, 22D, and 22E.
[0021]
These hydraulic oil chambers β, hydraulic oil holes T, take-out holes Q, oil grooves 37, 38, holes 27 and the like allow actuator hydraulic oil passages SF, SR, S1 to supply controlled hydraulic oil to each actuator A. S4, SL, SH, SJ, SG, SD, SE (shown in FIG. 11) are formed.
The oil drain passages γ of the control valves B are communicated with each other, and are opened from the oil drain groove 28 of the cover 4 to the transmission case 2 via the separate plate 8 from the inner valve body 11.
[0022]
The supply oil chambers α of the control valves BF, BR for the actuators AF, AR of the forward / reverse switching mechanism are communicated with each other through an oil passage 36, and the hydraulic oil from the main clutch control valve BM can be supplied to the oil passage 36. .
An end of a valve support 14 is inserted and fixed to an end of each spool hole 12 of the inner valve body 11. An oil drain hole 14a is formed in the valve support 14, and a ball-shaped valve element 17 that opens and closes the oil drain hole 14a is arranged. The solenoid 16 provided on the valve support 14 is capable of closing the oil drain hole 14a by exciting the valve body 17 when excited.
[0023]
The spool 13 is urged by a spring 30 so that an end thereof comes into contact with the valve support 14, and the valve support 14 also serves as a position regulating member for the spool 13. The spool 13 is formed with a peripheral groove 13a at an end and a slit 13b at an end face communicating with the peripheral groove 13a. The slit 13b also communicates with an oil discharge passage 14a in the valve support 14.
[0024]
An electromagnetic pilot valve C is constituted by the valve support 14, the solenoid 16, and the end of the valve body 17, and the pilot valve C is paired with each control valve B so as to face the spool 13. Are symmetrically arranged concentrically back to back with the partition wall 11a therebetween.
Oil passages UF, UR, U1 to U4, UJ, UG, UD, and UE are formed in the inner valve body 11 and the separate plate 8 so as to communicate with the circumferential groove 13a of the spool 13 of each control valve B. The path U communicates with the left and right pilot oil grooves 24 of the outer valve body 21 to form a pilot oil path P.
[0025]
Therefore, when the solenoid 16 is demagnetized, the pilot oil supplied to the oil passages UF, UR, U1 to U4, UJ, UG, UD, and UE is drained from the oil drain hole 14a, and when the solenoid 16 is excited. The oil drain hole 14a is closed by the valve element 17, fills the circumferential groove 13a and the slit 13b, applies a pilot pressure to the end of the spool 13, pushes the spool 13 against the spring 30, and pressurizes the supply oil. The chamber α can communicate with the hydraulic oil chamber β.
[0026]
The separate plate 8 regulates undesired flow of oil between the cover 4 and the inner valve body 11, and also includes a supply oil groove 23 and a pilot oil groove 24 and an oil passage U of the inner valve body 11 opposed thereto. A supply oil hole 35, a hydraulic oil hole T, and an oil passage U for transferring oil are formed between the supply oil chamber α, the working oil chamber β, and the like. S and the pilot oil passage P communicate with each other.
[0027]
1 and 11, depressurizing oil passages WF, WR are connected to oil passages UF, UR communicating with pilot valves CF, CR for a forward / reverse switching mechanism, and these oil passages WF, WR are inner valve bodies. 11, each having a non-return valve 33 and merging and connected to a pressure relief valve 32. The two check valves 33 may be one shuttle valve.
[0028]
The pressure relief valve 32 can be operated manually or by further depressing the clutch pedal 47 from a normal depression range (a range in which the main clutch control valve BM is operated), and the pressure relief oil passages WF and WR open the pressure relief valve 32. As a result, the pilot oil is discharged from the pilot valves CF and CR, the operation of the actuators AF and AR is released, and the forward / reverse switching mechanism is set to the neutral state.
[0029]
In FIG. 11, the hydraulic oil discharged from the hydraulic pump 7 among the triple pumps 7, 40, 41 driven by the engine passes through the steering controller 42 and is then supplied to the PTO clutch valve 43. The oil whose pressure has been adjusted here is supplied to the supply oil passage K of the outer valve body 21 of the valve system, and at the same time, the oil whose pressure has been adjusted to the lubricating oil is supplied to the actuators AF, AR, A1 to A4 , AL, AH, AJ, AG, AD, and AE.
[0030]
The hydraulic oil discharged from the other pumps 40 and 41 is supplied to the actuator 45 and the three-point link hydraulic device 46 of the tractor mounting work machine.
The hydraulic oil that has entered the supply oil passage K is directly supplied to the main clutch control valve BM and the control valves BL and BH, and is supplied to the control valves B1 to B4, BJ, BG, BD, and BE via the communication hole K2. It is supplied to the control valves BF, BR via the main clutch control valve BM. Further, the oil is supplied to the pilot valves CF, CR, C1 to C4, AL, AH, CJ, CG, CD, and CE of the interior valve unit 5 as pilot oil through the pressure reducing valve 25 of the circulation hole K1.
[0031]
The main clutch control valve BM is operated by the clutch pedal 47 when switching between forward and backward and when the vehicle is stopped, and the control valves BL and BH are operated by levers or buttons when switching the auxiliary transmission mechanism between high and low, thereby reducing shock during shifting. Is directly electrically controlled to perform pressure control for the actuators, and supplies actuator hydraulic oil to the actuators AL and AH.
[0032]
By electrically controlling the pilot valves CF, CR, C1 to C4, AL, AH, CJ, CG, CD, CE, the drainage of pilot oil is regulated, and the control valves BF, BR, B1 to B4, BJ , BG, BD, BE by pushing the spool 13 with the pilot pressure to switch the valve, to send the actuator hydraulic oil from the supply oil passage K to the actuator hydraulic oil passage S, and to transmit the actuator AF, AR, A1 to A4, AL, AG, AD and AE are operated appropriately.
[0033]
【The invention's effect】
According to the present invention described in detail above, in the valve in which the spool 13 for the control valve B for controlling the supply of the hydraulic oil to the actuator A is inserted into the spool hole 12 formed in the valve body 11, the spool end of the spool hole 12 is provided. A pilot oil passage P for supplying pilot oil that slides the spool 13 is connected to the section, and a pilot valve C for controlling the pilot oil passage P is disposed to face the spool 13, so that the control valve B and the pilot valve No oil passage between the C and C is required, the responsiveness is improved, and the device can be manufactured in a small size and at low cost.
[0034]
Further, in a valve in which a spool 13 for a control valve B for controlling supply of hydraulic oil to the actuator A is inserted into a spool hole 12 formed in the valve body 11, the spool 13 slides toward the spool end of the spool hole 12. A pilot oil path P for supplying a pilot oil to be connected is connected, a pilot valve C for controlling the pilot oil path P is disposed to face the spool 13, and a set of the control valve B and the pilot valve C is partitioned into a valve body 11 in the valve body 11. 11a, the oil passage between the control valve B and the pilot valve C is unnecessary, the responsiveness is high, the device can be manufactured compactly and inexpensively. A plurality of sets of valves can be efficiently arranged on the valve body 11.
[0035]
Further, a valve support 14 is fixed to the end of the spool hole 12 of the valve body 11, and the tip of the valve support 14 contacts the end of the spool 13, and the valve support 14 communicates with the pilot oil passage P. The oil passage 14a is formed, and the valve body 17 which opens and closes the oil passage 14a by being moved by the solenoid 16 is disposed in the oil passage 14a. An oil passage for the valve C can be formed.
[Brief description of the drawings]
FIG. 1 is a sectional plan view showing an embodiment of the present invention.
FIG. 2 is a side view of the entire valve system of the traveling vehicle.
FIG. 3 is a plan view of the exterior valve unit.
FIG. 4 is a cross-sectional plan view of the exterior valve unit.
FIG. 5 is a sectional view taken along line XX of FIG. 3;
FIG. 6 is a sectional view taken along line YY of FIG. 3;
FIG. 7 is an explanatory plan view showing an oil passage in the valve system.
FIG. 8 is a sectional view taken along line ZZ of FIG. 1;
FIG. 9 is a plan view showing an oil passage on the side of the interior valve unit.
FIG. 10 is a plan view showing an oil passage of a separate plate.
FIG. 11 is a hydraulic circuit diagram of the valve system.
[Explanation of symbols]
2 Transmission case 3 Opening 4 Cover 5 Interior valve unit 6 Exterior valve unit 7 Hydraulic pump 8 Separate plate 11 Inner valve body 12 Spool hole 13 Spool 14 Valve support 21 Outer valve body 21
A Actuator B Control valve C Pilot valve K Supply oil passage S Actuator operation oil passage P Pilot oil passage

Claims (2)

A valve having a spool (13) for a control valve (B) for controlling supply of hydraulic oil to an actuator (A) inserted into a spool hole (12) formed in a valve body (11).
A pilot oil path (P) for supplying pilot oil for sliding the spool (13) is connected to the spool end side of the spool hole (12), and a pilot valve (C) for controlling the pilot oil path (P). Is disposed opposite to the spool (13), and a set of the control valve (B) and the pilot valve (C) is symmetrically disposed concentrically in the valve body (11) with the partition (11a) interposed therebetween.
A set of the concentrically symmetrically arranged control valve (B) and pilot valve (C) is arranged in one valve body (11) for a forward / reverse switching mechanism and a main transmission mechanism;
In the valve body (11), a supply oil chamber (α), a hydraulic oil chamber (β), and a drain oil chamber (γ) facing each set of spool holes (12) are formed, and each control valve ( B) the oil drain chambers (γ) are communicated with each other ,
A valve system wherein a supply oil chamber (α) for two control valves (BF, BR) of the forward / reverse switching mechanism is communicated with each other through a communication hole (36) in a valve body (11) . A valve support (14) is fixed to the end of the spool hole (12) of the valve body (11), and the tip of the valve support (14) is brought into contact with the end of the spool (13), and the valve support is fixed. An oil passage (14a) communicating with the pilot oil passage (P) is formed in (14), and a valve body (17) that opens and closes the oil passage (14a) by moving to the oil passage (14a) by the solenoid (16). The valve system according to claim 1 , wherein the valve system is disposed .

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