JPH0861494A - Valve system - Google Patents

Abstract

PURPOSE: To provide a valve system which is high in the responsiveness, can be miniaturized and manufactured at a low cost, and can be easily assemble a restricting member to prevent the movement of one spool of two spools when the other spool is operated. CONSTITUTION: A pilot oil passage to feed the pilot oil to slide a spool 13 is connected to the spool end part side of a spool hole formed in a valve body 11, pilot valves CF, CR to control this pilot oil passage are arranged opposite to the spool 13, and a set of control valves BF, BR and the pilot valves CF, CR are concentrically and symmetrically arranged in the valve body 11 with a bulkhead 11a interposed therebetwben. A restricting member 9 which is interposed in the respective spool holes which are symmetrically arranged through the bulkhead 11a and prevent the movement of one spool 13 when the other symmetrically arranged spool 13 is operated is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve system for controlling, for example, a power shift transmission of a tractor.

[0002]

2. Description of the Related Art In a tractor, a power shift transmission has a forward / reverse switching mechanism that serves as a main clutch, a main transmission mechanism, an auxiliary transmission mechanism, a front wheel equal-speed switching mechanism, and the like, and a diff lock mechanism and the like. ,
Each of these mechanisms can be switched using a hydraulic clutch, a cylinder or the like.

The valves for controlling a large number of these hydraulic clutches, cylinders, etc. are centrally arranged at one location in order to facilitate maintenance and shorten the piping from the hydraulic pump. On the outer surface of the cover attached to close the internal inspection opening,
The multiple valves are centrally arranged. This type of valve uses a solenoid valve, but the type that directly controls large hydraulic pressure becomes large, and the type that indirectly controls the control valve using pilot hydraulic pressure becomes small. It is known that, in the case of such centralized arrangement, the one utilizing a pilot valve is preferable.

[0004]

In the conventional pilot control valve, the control valve and the pilot valve are independent of each other and are connected by a long oil passage, and are responsive to pressure loss or oil leakage. Are low, and each is small, but the total occupied area is large, the cost is high and the piping is troublesome.

SUMMARY OF THE INVENTION The main object of the present invention is to provide a valve system which is highly responsive, small in size, and inexpensive to manufacture by arranging a control valve and a pilot valve close to a spool hole formed in a valve body. To do.

[0006]

The technical means taken by the present invention to achieve the above object is a control for controlling the supply of hydraulic oil to the actuators AF and AR in the spool hole 12 formed in the valve body 11. In the valve in which the valve BF and BR spool 13 is inserted, the spool hole 12
A pilot oil passage P for supplying pilot oil for sliding the spool 13 is connected to the spool end side of the control valve BF, pilot valves CF and CR for controlling the pilot oil passage P are arranged to face the spool 13, and a control valve BF, A set of BR and pilot valves CF and CR is concentrically and symmetrically arranged in the valve body 11 with a partition wall 11a interposed therebetween.
One of the spools 13 that is symmetrically arranged and extends through both spool holes 12 that are symmetrically arranged so as to pass through a.
Is provided with a restraining member 9 that prevents the movement of the other spool 13 during the operation.

[0007]

[Operation] Spool hole 12 formed in the inner valve body 11
And a spool 13 constituting the control valves BF and BR,
Pilot valves CF, C facing the spool 13
R is arranged and these pilot valves CF, CR
When the pilot oil passage P is controlled by, the pilot pressure is applied to the end portion of the spool 13 and slid against the spring 30 to control the control valves BF and BR.

Spool holes 12 are concentrically arranged in the inner valve body 11 with a partition wall 11a interposed therebetween, and a pair of control valves BF and BR and pilot valves CF and CR are formed back to back to occupy an occupied area. It is getting smaller. Further, since the spool holes 12 are concentrically arranged via the partition wall 11a, it is possible to easily install the check member 9 that prevents the movement of the other spool 13 when one of the symmetrically arranged spools 13 operates.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 13, reference numeral 2 denotes a transmission case having a tractor transmission built therein, and an inspection opening 3 is formed on the upper surface thereof, and a cover 4 for opening and closing the opening 3 is attached. The internal valve unit 5 is attached to the inner surface of the cover 4 via the separate plate 8.
The exterior valve units 6 are attached to the outer surfaces of the valve systems, respectively.

As shown in FIG. 12, this valve system controls almost all actuators required for traveling of the tractor. As the actuators, the actuators AF, AR of the forward / reverse switching mechanism and the main transmission mechanism are used. Actuators A1 to A4, auxiliary transmission mechanism actuators AL and AH, front and rear wheel differential lock mechanism actuators AJ and AG, and front wheel equal speed switching mechanism actuators AD and AE.

The actuator A of each of these mechanisms is, for example, a hydraulic clutch that connects the rotary shaft and the transmission gear, a hydraulic cylinder that engages the differential lock body with the differential gear, and a hydraulic cylinder that moves the shifter engaged with the transmission gear. May be The exterior valve unit 6 is shown in FIGS.
As shown in 0, the main clutch control valve BM that supplies pressure oil to the actuators AF and AR of the forward / reverse switching mechanism, and the control valves BL and BH that controls the actuators AL and AH of the auxiliary transmission mechanism are provided to the outer valve body 21. When,
Pressure detection switch R communicating with each of these control valves B
M, RL and BH are attached. The control valve B
Electromagnetic proportional valves are used for M, BL, and BH, which are larger than the control valve B for pilot control described later.

Reference numeral K denotes a supply oil passage connected to the hydraulic pump 7 for supplying pressure oil, which is formed through the inside of the outer valve body 21 and communicates with the control valves BM, BL, BH.
Circulation holes K1 and K2 are branched from the supply oil passage K.
Further, in the outer valve body 21, an actuator operating oil passage SJ for supplying actuator operating oil to the actuators AJ and AG of the front and rear wheel diff lock mechanism and the actuators AD and AE of the front wheel equal speed switching mechanism,
Connections 22J, 22G, 2 forming SG, SD, SE
2D and 22E are provided.

The cover 4 has eight take-out holes QF, QR, and Q1 to Q through which the actuator operating oil circulates within its wall thickness.
4, QL, QH are formed, and the extraction holes QF, QR, Q1 to Q4, QL, and QH are formed at one end on the inner surface side of the actuators AF and AR of the forward / reverse switching mechanism, the actuators A1 to A4 of the main speed change mechanism, and the auxiliary transmission mechanism. A connection tool connection port NF for connecting to the actuators AL and AH of the speed change mechanism,
NR, N1 to N4, NL, and NH are formed, and the take-out holes Q1 for the actuators A1 to A4 are formed on the outer surface of the cover 4.
To Q4 are provided with pressure detection switches R1 to R4.

The pressure detecting switches RM, RL, BH,
R1 to R4 are provided to detect the pressure of each corresponding control valve B and to sequence-control the operation timing. Cover 4 facing the separate plate 8
A pair of left and right supply oil grooves 23 for supplying actuator hydraulic oil communicating with the flow hole K2, and a pair of left and right pilot oil for supplying pilot oil for communication with the flow hole K1 on both left and right sides of the joint surface (lower surface). The groove 24 and the groove 24 are formed to be long, and the pressure reducing valve 25 is provided in the circulation hole K1 to generate low pressure pilot oil from high pressure actuator working oil. The left and right supply oil grooves 23 and the left and right pilot oil grooves 24 communicate with each other.

In FIGS. 1, 2, and 8 to 11, the internal valve unit 5 is provided with ten sets of valves, which are a combination of a control valve B and a pilot valve C. A spool hole 12 is concentrically formed in the inner valve body 11 with a central partition wall 11a interposed therebetween.
The columns are arranged. Control valves BF, BR and pilot valves CF, CR are for forward / reverse switching mechanism, control valves B1-B4 and pilot valves C1-C4 are for main transmission mechanism, control valves BL, BH and pilot valve C
L and CH are for the auxiliary transmission mechanism, respectively.

A supply oil chamber α, a working oil chamber β, and a drain oil chamber γ are formed in the inner valve body 11 so as to face the spool holes 12. The chamber β is selectively communicated with the supply oil chamber α and the discharge oil chamber γ on both sides, and the supply of the operation oil from the supply oil chamber α to the actuator A via the operation oil chamber β and the operation oil chamber β, The discharge of hydraulic oil from the actuator A can be controlled via the oil discharge chamber γ.

Each supply oil chamber α communicates with the supply oil groove 23 through the oil hole 35 of the separate plate 8, and the supply oil chamber α for the control valves BF and BR of the forward / reverse switching mechanism.
Are communicated with each other through a communication hole 36 in the inner valve body 11. Each hydraulic oil chamber β of the control valves BF and BR of the forward / reverse switching mechanism and the control valves B1 to B4 of the main transmission mechanism
Is an oil groove formed on the joint surface side of each separate plate 8 of the inner valve body 11 and the outer valve body 21 and hydraulic oil holes TF, TR, T1 formed in the separate plate 8.
Through T4, take-out holes QF, QR, Q in the cover 4
It communicates with 1-Q4. In addition, the control valves BL and BH of the auxiliary transmission mechanism are such that one is through the oil groove 37 of the outer valve body 21 and the other is through the hole of the separate plate 8 and the oil groove 38 of the inner valve body 11 and the take-out holes QL and QH. Is in communication with.

The control valve BJ of the front and rear wheel differential lock mechanism,
Each of the working oil chambers β of the BD and BE of the BG and the front wheel double speed switching mechanism includes an oil groove of the inner valve body 11, working oil holes TJ, TG, TD, TE formed in the separate plate 8, the cover 4 and the outer valve body. The connection tools 22J, 22G, 22D, and 22E communicate with each other through four holes 27 of 21.

Actuator hydraulic oil passages SF, SR for supplying controlled hydraulic oil to each actuator A by the hydraulic oil chamber β, hydraulic oil hole T, take-out hole Q, oil grooves 37, 38, hole 27, etc. , S1 to S4, SL, SH,
SJ, SG, SD, SE (shown in FIG. 12) are formed. The oil discharge passages γ of the control valves B are communicated with each other, and are opened from the inner valve body 11 through the separate plate 8 to the oil discharge groove 28 of the cover 4 into the mission case 2.

Actuator A of forward / reverse switching mechanism
The oil supply chambers α of the control valves BF and BR for F and AR are connected by an oil passage 36, and the hydraulic oil from the main clutch control valve BM can be supplied to this 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 communicating with the spool hole 12 is formed in each valve support body 14, and the oil drain hole 14a is also formed.
A valve body 17 made of a ball for opening and closing is provided. Further, each valve support 14 is provided with a solenoid 16, and the solenoid 16 is capable of closing the oil drain hole 14a by pushing the valve 17 by exciting it.

The spool 13 is biased by a spring 30 so that its end portion abuts on the valve support body 14, and the valve support body 14 also serves as a position regulating member for the spool 13. As shown in FIG. 13, the spool 13 is provided with a circumferential groove 13a at the end and a slit 13b at the end face communicating with the circumferential groove 13a.
3b also communicates with the oil drain hole 14a in the valve support 14.

An electromagnetic pilot valve C is constituted by the ends of the valve support 14, the solenoid 16 and the valve body 17. The pilot valve C faces the spool 13 and is paired with each control valve B. , This set is concentrically and back-to-back concentrically with the partition wall 11a in between. In the inner valve body 11 and the separate plate 8, as shown in FIG. 11, the oil passages UF, UR, U1 to communicate with the circumferential groove 13a of the spool 13 of each control valve B.
U4, UJ, UG, UD, and UE are formed, and the oil passages U are formed in the left and right pilot oil grooves 24 of the outer valve body 21.
And a pilot oil passage P are formed. Each oil passage U is provided with a diaphragm t (shown in FIG. 12),
The pilot pressure between each throttle t and the pressure reducing valve 25 is maintained.

Therefore, the oil passages UF, UR, U1 to U4, U
Pilot oil supplied to the opening end side of the spool hole 12 via J, UG, UD, and UE is discharged through the circumferential groove 13a and the slit 13b of the spool 13 when the solenoid 16 of the pilot valve C is demagnetized. When the solenoid 16 is drained from the oil hole 14a and the solenoid 16 is excited, the oil drain hole 14a
Since a is closed by the valve body 17, the circumferential groove 13a and the slit 13b are filled, pilot pressure is applied to the end of the spool 13, and the spool 13 is pushed against the spring 30 to supply the oil in the oil supply chamber. The α can be communicated with the hydraulic oil chamber β.

The separate plate 8 regulates the undesired flow of oil between the cover 4 and the inner valve body 11, and also supplies the oil supply groove 23 and the pilot oil groove 24 and the inner valve body 11 opposed thereto. A supply oil hole 35, an operation oil hole T, and an oil passage U for transferring oil are formed between the oil passage U and the supply oil chamber α, the operation oil chamber β, and the like, and the supply oil passage K and the actuator are provided. The hydraulic oil passage S and the pilot oil passage P communicate with each other.

1, 2 and 12, the actuators AF of the forward / reverse switching mechanism, the control valve BF for AR,
In the spool hole 12 of the BR, there is provided a restraining member 9 made of a bar member that penetrates the partition wall 11a and is slidably supported by the partition wall 11a. When the spool 13 of one of the symmetrically arranged control valves BF and BR is pressed by the pilot pressure, the check member 9 is pushed by the one spool 13 and contacts the other spool 13.
The movement of the other spool 13 is restricted, and the control valve B
It prevents F and BR from operating at the same time.

Further, the spool holes 1 of the control valves BF and BR for the actuators AF and AR of the forward / reverse switching mechanism.
The pressure relief oil passages WF and WR formed in the inner valve body 11 are connected to the opening end side of 2, and therefore these oil passages WF and WR are connected to the pilot valves CF and CR for the forward / reverse switching mechanism. Is communicated with the oil passages UF and UR which are communicated with. A check valve 33 is provided in each of the oil passages WF and WR, and these oil passages WF and W are also provided.
R merges and is connected to the pressure relief valve 32.
It should be noted that a shuttle valve that allows only the pressure oil from one side to flow to the pressure relief valve 32 is provided at the confluent portion 50 of the oil passages WF and WR, so that the two check valves 33 can also be used as one valve. it can.

The pressure relief valve 32 can be operated manually or by further depressing the clutch pedal 47 from the normal depression range (the range in which the main clutch control valve BM is operated). By opening the pressure relief valve 32, Forward / reverse switching mechanism actuator AF,
The pilot oil selectively supplied to the spool holes 12 of the AR control valves BF and BR presses the check valve 33,
Even if the drain holes 14a of the pilot valves CF and CR are drained through the depressurizing oil passages WF and WR and the drain holes 14a of the pilot valves CF and CR are closed by the valve body 17, the pressing force of the spool 13 by the pilot pressure is released. The spool 13 is returned by the spring 30, and the actuators AF, A
The operation of R is released, and the forward / reverse switching mechanism is set to the neutral state.

In FIG. 12, the hydraulic oil discharged from the hydraulic pump 7 among the triple pumps 7, 40 and 41 driven by the engine is supplied to the PTO clutch valve 43 after passing through the steering controller 42. 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 passed through the lubricating oil passage 44 and the actuators AF, AR, A1.
To A4, AL, AH, AJ, AG, AD, AE.

The hydraulic oil discharged from the other pumps 40 and 41 is used as the actuator 4 of the working machine mounted on the tractor.
It is supplied to the 5- and 3-point link lifting hydraulic device 46 and the like.
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, BH, and is supplied to the control valves B1 to B4, BJ, BG, B via the flow passage K2.
It is supplied to D and BE, and is supplied to the control valves BF and BR via the main clutch control valve BM. Further, the pilot valves CF, CR, C1 of the internal valve unit 5 become pilot oil through the pressure reducing valve 25 of the circulation hole K1.
To C4, AL, AH, CJ, CG, CD, CE.

The main clutch control valve BM is a pilot valve C when switching between forward and reverse and when the vehicle is stopped.
The control valves BL and BH are operated in conjunction with F and CR, and are operated when switching the auxiliary transmission mechanism to high or low, or in conjunction with the pilot valves A1 to A4 of the main transmission mechanism. BL and BH are directly and electrically controlled to perform pressure control for shock reduction at the time of gear shift, and the actuator hydraulic fluid is supplied to the actuator A.
Supply to L and AH.

Pilot valves CF, CR, C1 to C
By electrically controlling 4, AL, AH, CJ, CG, CD, CE, the discharge of pilot oil is regulated, and control valves BF, BR, B1 to B4, BJ, BG, BD, B
The spool 13 of E is pushed by the pilot pressure to switch the valve, the actuator working oil is sent from the supply oil passage K to the actuator working oil passage S, and the actuators AF, A
R, A1 to A4, AL, AG, AD, and AE are appropriately operated.

[0032]

According to the present invention described in detail above, the actuator A is provided in the spool hole 12 formed in the valve body 11.
A control valve BF for controlling the supply of hydraulic oil to F and AR,
In the valve in which the BR spool 13 is inserted, 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 CF for controlling the pilot oil passage P is connected. , CR are arranged to face the spool 13, an oil passage between the control valve B and the pilot valves CF, CR is not required, the responsiveness is high, and the small size and low cost can be manufactured.

Further, since the set of the control valves BF and BR and the pilot valves CF and CR are arranged concentrically and symmetrically in the valve body 11 with the partition wall 11a interposed, the control valves BF and BR and the pilot valve CF are arranged. , CR, no oil passage is required, responsiveness is high, small size and low cost can be manufactured, and more than one set of valves can be efficiently arranged in one valve body 11.

Further, since the spool holes 12 are concentrically arranged via the partition wall 11a, the restraining member 9 for preventing the movement of the other spool 13 when one of the symmetrically arranged spools 13 operates can be easily incorporated. .

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view showing a main part of the present invention.

FIG. 2 is a cross-sectional plan view of the entire valve system of the traveling vehicle.

FIG. 3 is a side view of the entire valve system.

FIG. 4 is a plan view of an exterior valve unit.

FIG. 5 is a cross-sectional plan view of an exterior valve unit.

6 is a cross-sectional view taken along line XX of FIG.

7 is a cross-sectional view taken along the line YY of FIG.

FIG. 8 is an explanatory plan view showing an oil passage in the valve system.

FIG. 9 is a sectional view taken along line ZZ of FIG.

FIG. 10 is a plan view showing an oil passage on the internal valve unit side.

FIG. 11 is a plan view showing an oil passage of a separate plate.

FIG. 12 is a hydraulic circuit diagram of the valve system.

FIG. 13 is a perspective view of a spool.

[Explanation of symbols]

 2 Mission case 3 Opening 4 Cover 5 Internal valve unit 6 External valve unit 7 Hydraulic pump 8 Separate plate 9 Checking member 11 Inner valve body 12 Spool hole 13 Spool 21 Outer valve body 21 A Actuator B Control valve C Pilot valve K Supply oil passage S Actuator operating oil passage P Pilot oil passage

Claims (1)

[Claims] 1. Control valves (BF), (BR) for controlling supply of hydraulic oil to actuators (AF), (AR) in spool holes (12) formed in a valve body (11).
In the valve having the spool (13) inserted therein, a pilot oil passage (P) for supplying pilot oil for sliding the spool (13) is connected to the spool end side of the spool hole (12), and this pilot oil passage is connected. Pilot valves (CF) and (CR) for controlling (P) are arranged to face the spool (13), and control valves (BF) and (BR)
Both spools and pilot valves (CF) and (CR) are concentrically and symmetrically arranged in the valve body (11) with a partition wall (11a) interposed therebetween, and both spools are symmetrically arranged through the partition wall (11a). A check member (9) interposed between the holes (12) and preventing movement of the other spool (13) when one of the symmetrically arranged spools (13) operates. Valve system to do.