JPS6159006A - Control valve unit for displacement control of agricultural machine - Google Patents

Abstract

PURPOSE:To eliminate necessity for any complicated link mechanism as well as to prevent any shock occurring when an agricultural machine changes its position, by setting up, a control valve in form of a spool valve and operating this spool valve by means of the rotation of a pulse motor so as to control the speed of spool displacement. CONSTITUTION:A control valve 2 is set up in form of a spool valve. This spool valve is so arranged as capable of making sliding motion following the rotation of a pulse motor 4. This pulse motor 4 is controlled by an electric controller 59 including a pulse generator. And this controller 59 outputs a control pulse of variable width and frequency. The spool valve is slowly controlled at the initial stage of displacement etc. by means of this control pulse, thus preventing shock(s) on the agricultural machine.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field/Field This invention relates to agricultural operation 9: control valve 'JI[f for controlling machine displacement], in which a control valve for oil path switching is configured as a spool valve.

The rotary tiller, which is used for tillage work by being towed by a tractor, is attached to a foot device installed on the tractor.
As is well known, the hydraulic lift device is moved up and down.
Rokuri tiller? It is not only used for raising and lowering between an upper waiting position and a lower working position;
It is also used to finely move the rotary tiller up and down, such as to set a constant plowing depth and constant υF rotation load while the rotary tiller is in the working position. And a rotary tiller? 117 of a hydraulic lift device that moves up and down
The operation of the cylinder cylinder is controlled by a control valve gW.

In addition, while working with a rotary tiller, the left-right posture is controlled by the rocking displacement of the tiller in response to the left-right inclination of the field, thereby achieving an even plowing depth on both sides. Displacement control, also called rolling control or horizontal control, is also well known, and the construction of the tiller rocking displacement control 1'l, 4eHI cylinder for this purpose7J
In a combine harvester installed at the front of a machine with a reaping machine that is moved up and down by a hydraulic pressure device, the cutting height is determined by the cutting height sensor. In response to the detection signal, the entire reaping machine is finely moved up and down to maintain the appropriate cutting height, and the control valve device for the 7-cylinder oil field lift can be used for this control as well. .

Even if the rice transplanter is a riding rice transplanter that is connected to a tractor-type machine with a housing so that the entire rice transplanter can be raised and lowered, it is difficult to do rice planting work in order to control the planting depth at a constant level. Hydraulic lift cylinders are used to move up and down finely, and a control valve device is also used in this case.

The present invention relates to a control valve device +1 which is used for displacement control of an agricultural working machine as exemplified above.

Problems with the prior art: This type of control valve device moves to the operating position in response to the detection signal from a sensor that detects the position and posture of the working machine, the slope of the field, the quality of cutting, the depth of seedling planting, etc. It has been constructed with a servo valve that is displaced and returned to a neutral position when the working horse is moved to the appropriate position or posture, but generally a servo link mechanism connects the sensor and the valve spool. Alternatively, the displacement can be performed mechanically through four feedback links connecting the working machine and the gear (for example, the
(Refer to Publication No.-42107).

This kind of link mechanism has a complicated structure, and has problems such as reduced accuracy due to the play that necessarily exists at the connection points between link elements, and poor responsiveness due to being mechanical. , has.

What can be considered is the use of solenoid valves, and in fact, solenoid valves have been used for the above-mentioned rolling control (horizontal control), for example, as disclosed in Japanese Patent Application Laid-open No. 55-23918. There is.

However, solenoid valves have the problem of being too responsive. In other words, a solenoid valve is instantaneously displaced in an on-off manner by the excitation of a solenoid, but agricultural working machines that are relatively heavy and have a large inertia have a difference between when the displacement begins and when the displacement ends. The nature of this is that it must be displaced slowly to prevent the occurrence of shock. This kind of work equipment displacement is achieved by slowing down the initial and final stages of valve spool displacement and giving a specific speed to the oil passage throttling effect. It is impossible to do so, and it is difficult to prevent shock. For example, a control valve for a hydraulic lift 71J installed on a front loader, for example, a control valve for a hydraulic lift 71J installed on a front loader, for example,
176 Between neutral positions as disclosed in FAr publication,
It is composed of a 4-position valve with a floating position that allows the lift arm equipped with a packet l to freely lower the lower part 11, in addition to the ascending action position and the descending action ill (ff) position. However, it is difficult to configure a solenoid valve to have all four or more positions.

Purpose This output L111 solves the above-mentioned problem of a control valve that is mechanically displaced and the above-mentioned problem of an electromagnetic control valve that is positioned electromagnetically by excitation of a solenoid. The aim is to

In other words, the object of the present invention is to provide a system that does not use a link mechanism with a complicated structure, has high accuracy and good responsiveness, and can easily control the spool displacement speed to prevent shocks when the work equipment is displaced. It is an object of the present invention to provide a new control valve device for controlling the displacement of an agricultural working machine, which is easy to obtain and can be easily constructed into a valve with four or more positions.

The control valve device for controlling the displacement of vll'1:1 work machine invented by C has the control valve of the oil path switching river configured as a spool valve, and the control valve device has a spool valve. tl
l m 11 control valve % ip,
Re-Itli rotational movement! Movement conversion gate structure that converts to luck #+? The spool 17C of the intervening spool valve is characterized in that the spool 17C of the spool valve is completely submerged and the spool is slidably displaced by the rotation of the pulse motor.

Invented by Tsurugi, electric pulses are applied at a constant small angle, and a rotating pulse motor is used to slide and displace the entire spool of a control valve over a constant small distance.
The amount of displacement of the spool can be controlled by the number of pulses applied to the pulse motor, and the displacement speed of the manosuguru can be controlled by the frequency of applying pulses over time. Pulse width 'f! as required. : If you change it, you can also change and control the amount of spool displacement for each pulse.

Figures 1 to 10 show the first q (relating to the male side), which was implemented by this inventor as an elaborate control valve device for a hydraulic lift device installed in a tractor. This is a complete circuit diagram of the hydraulic circuit including the control valve bag al.The control valve for M path switching is
There is a work indicated by the symbol 2. The fflZtn diagram shows the specific construction of the control valve system, of which Figure 8 shows the operation when the control valve 2r is moved to the upward working position, and the fm9.10 diagram shows the operation when the control valve 2r is moved to the downward working position. The effects of the DIC transfer are shown respectively.

Control pulp 2 as shown in Figure 4 and Figures 8 and 9.
The spool valve has a hollow spool 8 which is fitted into a valve hole passing through a valve case. A pulse motor 4 is mounted on one end of the pulp case, and a sliding support 6, which is driven forward and backward by the pulse motor 4 through an F motion conversion mechanism 5, is thrown against one end of the spool 3. be.

The other end of the spool 3 is provided with a spring 7 that urges the entire sliding metal part of the spool 3 to slide in 6 directions.
The I″9 sliding metal fitting 6 is held in place by the annular stepped portion 6a on the metal fitting 6 due to the urging force of the spring 7.

When the pulse motor 4 is rotated in the forward direction due to the neutral state force of the control valve 1 shown in FIG. When the spool 3 is pushed and moved to the upward movement position 1 stroke as shown in FIG. 8, and the pulse motor 4 is reversed, the sliding metal fitting 6 is slid to the right in the diagram. The force of the spring 70 causes the spool 3 to be moved into the lower operating position as shown in FIG. The spool 3 is operated by an Eri spring 7 for reverse rotation of the pulse motor 4 from the upward working position shown in FIG. 8, and by normal rotation of the pulse motor 4 from the downward working position 1u shown in FIG. Pushed by the sliding hardware 6, each is returned to the neutral position shown in FIG.

In FIG. 1, 8 is a lift cylinder of a hydraulic lift device, 9 is an oil tank, IO is a hydraulic bong for completely supplying hydraulic oil from the oil tank 9 to the lift cylinder 8, and 11 is an actuator supplied to the lift cylinder 3. 12 is a stop valve for keeping the lift cylinder 8 in a stopped state; 13 is a mellow return pulp for reducing the lift cylinder 8 at low speed; 14 is a beam 7 to the cylinder 8. This is an overload relief valve to avoid excessive hydraulic pressure, and these valves are provided outside the control valve unit and have a conventional structure.

Similarly, as shown in FIG.
C is a pump boat 1 connected to the hydraulic pot 10;
5P, and a cylinder port 15C connected to the lift cylinder 8 via the stop pulp 12 and mellow return pulp 13, and both boats 15P and 15C are connected by an oil supply circuit 16. The control valve 2 is inserted into the oil supply circuit 16,
Further, the oil supply circuit +61C is on the secondary side of the control valve 2, and a load check valve I7 is inserted therein to completely prevent backflow of oil from the lift cylinder 8. control pal 7
``J m 1 fd Also, with the control valve 2 at the neutral position [N and the downward action position, drain the oil flowing into the pump boat 15P at a low temperature. 2 rising action position H
The flow rate control valve 19 for fully controlling the amount of oil supplied to the lift cylinder 8 is placed in the lowering position of the control valve 2. The next unload check valve 20 to be drained,
We are prepared.

Of these, the unload valve 18 and the flow control valve 19 are respectively connected to the oil supply circuit 16 on the primary side of the control valve 2.
Branched from t and inserted into t drain circuit 21.22, and t
The unload check valve 20 is inserted into a drain circuit 23 branched from the oil supply circuit I6 on the secondary side of the load check valve 17.

' In the zt diagram, 24 is the control valve 2.
The control valve 2 has a four-way back pressure action circuit that applies back Ef to the unloaded pulp 18 only at the rising action position 11U, and the same back pressure action circuit is reversed at the neutral position N and the descending action position. The valve 18 is configured to completely release the back pressure of the unloaded pulp 18 via the valve 24 and cause the valve 18 to perform a hydraulic unloading operation. control valve 2
incorporates a variable throttle 9 part 25 that throttles the oil supply circuit 16 at its upward action position tffU, and the combination of this variable throttle part 25 and the flow rate control valve 19 allows the 0 flow rate *
In order to achieve +U control, the oil field of the oil supply circuit 16 of the control pulse 2 secondary IItlJ is made to act as back pressure on the flow rate control valve 19 by the back pressure applying circuit 27 in which the throttle 26 is fully inserted. In the illustrated case, the unload check valve 20 is configured as a valve that opens when the control valve 2 is placed in the lowering position and applied with pilot oil pressure via the pilot circuit 28. explain.

To explain the specific construction of the control valve bag @1, as shown in Fig. 4.5, the load check valve 1 described above is
7. Unload pulp 18 and unload check valve 2
0 are installed in the valve case in parallel with the spool 3, and the flow control well 19 is installed in the hollow part of the spool 3 in parallel with the spool 3. The illustrated control valve device I is installed on a tractor by abutting against the outer surface of the mission case wall W (FIG. 4) of the surface sl tractor shown in FIG. As shown in , the above-mentioned pump boat 15P, cylinder boat 15c, and 4 drain boats 15T are opened on the t-plane S.
15T, 15T, 15T4 are provided.

Of these, pump boat I5P and cylinder boat 15c
are superimposed on the open ends of the corresponding oil passages in the mission case wall W, and the two primaries are communicated through the slots 80.31. It is designed to communicate with the inside of the transmission case through the hole.

As shown in Figure 4, the pulp case contains bongpo-1-
15F) An M path 32 extending in the opposite direction of the mission case wall W is formed by opening at the outer peripheral position of the spool 3 and extending over the spool 3 position on t,
This oil passage 32 is communicated with an annular groove 35 on the outer circumference of the spool 3 via an oil passage 33 parallel to the spool 3 and an oil passage 34 parallel to the circuit 32. Annular grooves 36 and 37 are formed on one side and the other side of the annular groove 35 on the outer circumference of the spool 3 at appropriate intervals in the length direction of the annular groove 35 and the spool 3. One of the annular grooves 36 is MU
An oil passage 38 parallel to the passage 32 is formed with a perforated end closed by the transmission case wall W, and communicated with the primary side of the load check valve 17. 1fc The other annular groove 37 communicates with the oil passage 39 parallel to the oil passage 32.degree. 38 to the Eridrain boat 15L. As shown in FIGS. 4-6, an oil path 40 along the direction across the spool 3 and the unloaded pulp 18, and an oil path 41 along the direction cutting the load check valve 17 and the unload check valve 20, It is thrown into the valve case parallel to the beans, and r+
The A and I passages 40 of the iJ player are used to direct the annular groove 35 and the annular groove 42 on the next side of the unloaded pulp 18. The latter oil passage 41 is connected to the cylinder boat 15C by an oil passage 43 shown in FIGS. It is said to be used to connect to 15C. The secondary side of the unloaded pulp 18 and the secondary side of the unloaded check valve 20 are communicated with the drain boat 15Tt through an oil passage 44, as shown in FIG.

In addition to the annular grooves 35 and 3637, two other annular grooves 45 and 46t-1 annular grooves 37 are also formed on the outer circumferential position of the spool 3, and are located on the sliding hardware 6 side and spaced apart from each other. It is. Of these, the annular groove 45 on the side far from the sliding metal fitting 6 is connected to the unloaded pulp 1 by an oil passage 47 shown in FIGS.
It is connected to the back of 8. Also, as shown in FIG. 5, behind the Amerode check valve 20, there is a
A piston 48 is provided concentrically with the annular groove 46 of the annular groove 45, 46 on the side closer to the sliding hardware 6.
As shown in FIG. From the middle of the small diameter oil passage 49, the other small diameter oil passage 5IVC shown in FIG.
It is connected to the drain boat 15″r3,
Further, the space on the curved surface side of the piston 48 mentioned above is communicated with the drain boat 15T4 through an oil passage 52, as shown in Figure 5.

While the pulp case has an oil passage as described above, the spool 3 of the control valve 2 has a gr
Four lands 3a+ 3b+ 3c+ 3d are provided from the spring springs to the sliding hardware side.

Of these, the land 3a has an annular groove 35 in the neutral position shown by V in FIG. 154 and in the downward operating position shown in FIG.
The communication between the annular grooves 35 and 36 is completely cut off, and in the raised position shown in FIG. Therefore, the oil passage 38 carried to the primary side of the load check valve 17 is communicated with the pump bow 1-15P only at the lifting action position U of the control bar A/gu 2.

The land 3b has an annular groove 35 communicating with the pump port 15P and the drain port 1 no matter where the spool 3 is placed.
Communication between annular grooves 37 that communicate with sTIK? It is set up to block it.

Next, the land 3 is different from the neutral position shown in Fig. W14 and the downward action position rα shown in Fig. 9 of the drain=≠, j
-'- The annular groove 37 that communicates with the toe 15T and the annular groove 45 that communicates with the back of the unloaded pulp 18 are made to communicate with each other.
7.45 and communicates with the annular groove 45 through the annular groove between the gold lands 3c and 3d. Therefore, at the neutral position N of the control valve 2 and the downward working position [D], hydraulic pressure is removed from behind the unloading pulp 18 to the drain boat 15T, and at the rising working position U, the pump boat 15 is released behind the unloading pulp 18.
The hydraulic pressure of P acts as a back pressure and becomes 0. Finally, land 3dl-j, the oil chamber 50 behind the piston 48 provided behind the unload check valve 20 as described above.
The annular r446 that communicates with the oil passage 32 through the annular slot between the lands 3c and 3d, and therefore with the pump port 15P, is provided only in the elaborate lowering position shown in FIG. .

The control valve 2 or its spool 3 is configured as a VC for switching oil passages as described above, whereas the spool 3 is slidably displaced by a pulse motor 4 as described above. There is.

As shown in FIGS. 2 and 4, the pulse motor 4 is attached to the pulp case via a support cylinder 52 having flanges 52a and 52bji at both ends, and the base end of the sliding metal 6 is attached to the support cylinder. 52 is fitted. The above-mentioned specific motion conversion rock groove 5i-1: As shown in FIG.
An external thread 54al is formed on the rotating hardware 54 connected to the motor shaft 4a through No. 3, and an internal thread 6bk is formed on the base end portion of the moving hardware 60, which is connected to the external thread 54a.
In order to make the pin 55 screwed onto the support tube 52 appear in the long groove hole 6d formed on the outer circumferential surface of the proximal end of the sliding metal fitting 6, the sliding metal fitting 6 is attached to the support tube. 52, the motor m4 is supported in a sliding manner but not relatively rotatable.
The rotational movement of the motor shaft 4a is transferred to the sliding metal piece 6 by the sound screw coupling between the rotating metal piece 54, which rotates integrally with the rotating metal piece 54, and the sliding metal piece 6, which is supported non-rotatably.
It is configured to convert into linear motion. 'ma f
Similarly, as shown in Figure @4, the spring 7 has a snap ring 56 attached to the inner peripheral surface of the other end of the spool 3, and a spring receiver ring 57 is received by the snap ring 56 from the opposite side of the sliding metal fitting 6. Both ends are received by a lid 58 mounted on the end face of the pulp case and the spring receiver ring 57, and are used inside the pulp case.

As shown in Fig. 1), the electric controller 59 including the pulse generator is connected to the VC pulse motor 4, and the controller 59 controls the extension/retraction position of the lift cylinder 8, and hence the lifting/lowering position of the work equipment @ complete set. It can be set as the value Sa, and a detection signal from the plowing depth sensor S1 or load sensor S can be input. The electric controller 59 generates electric pulses according to a preset program according to set values and sensor signals, and the pulse motor 4t can selectively rotate forward or reverse. In the relationship between the electric pulse and the sliding displacement of the spool 8, the maximum displacement of the spool/I/3 from the neutral position 1 shown in FIG. The maximum amount of displacement is said to be about 1 m, but even if the spool 3 is 25μ (microns) with the pulse motor 4/1liF1E inputted by Photohar + Lume, it will be possible to slide the spool 3 over a small distance. is set to .

The oil passage 38 located on the primary side of the load check valve I7 is communicated with the pump boat 15P only at the upward operating position rt:tU of the control valve 2, as described above, by switching the oil passage using the spool 3. As shown in FIG. 4, the load check valve 17 is seated against the valve seat 17b from the opposite side of the oil passage 38 by the force of the valve spring 17a. Acting cylinder boat 15C oil aEk valve spring 1
A diagonal oil passage hole 17c leading into the installation space 7a is fully drilled. Note that the valve spring 17a is connected to the bottle 6 thrown in a floating manner.
(Bending is prevented by IK.

This load check valve 17 is controlled by the force of the valve spring 17a and the cylinder boat [5(
, o bend pressure and J-t) to the gills shown in Fig. 4, tfc
In the downward working position, the force of the valve spring 17a keeps the valve seat 17bK seated in the closed state as shown in Fig. 47.9, and in the rising working position U, the pump boat 15F for i'μ on the primary side is maintained. In an oil field, the valve leaves the valve seat 17b and retreats to the open state in the gills shown in Fig. 8e and 7d.

Next, unload pulp ■ By switching the oil path using the spool 3 attached to 8, the control valve 2 is placed in the neutral position N and the downward action position as described in I, and the annular groove 42 located on the next side is the pump It is communicated with the boat 15P, and back pressure is released to the drain boat 15T+. To this unload pulp 18? -1 Annular pressure receiving surface 18
The unloading pulp 18 resists the force of the valve spring 18b due to the hydraulic pressure of the pump bow 15F acting on the pressure receiving surface 18a at the above-mentioned neutral position N and descending action position i1D where the back pressure is released. , in the neutral position @N, as shown by the chain line in Fig. 5, and in the downward action position, as shown in Fig.
The oil flowing into the annular groove 42 is transferred to the I'dll passage 44.
Drain all 44 at low pressure, for example about 5 k,/d, into a drain boat 15T. control valve 2
At the lifting action position U, the hydraulic pressure of the pump boat 15P is applied as back pressure by switching the oil path by the spool 3, as described above, so that the unloaded pulp 18 is
It is closed as shown by the solid line in the figure.

Next, the flow rate control valve 19rr is installed in the hollow part of the sgur 3 as described above, and as shown in FIG. It is brought into contact with the tip of the sliding metal fitting 6 fitted into the end of the spool 3, and a curved wiring circuit 32 is provided in the outer circumferential space of the rond part 19a. , connect the control valve I with the communication part ↓f) in the oil passage hole 61 bored in the spool 3.
All ports on the 9-next side are connected to all ports 15PK. Maf
c A spring holder 6 that is fitted into the spool 3 in abutment with the snap ring 56 and receives the base end of the valve spring 19b.
2 is bored with an oil passage that connects both annular grooves 36 to the rear of the control valve 19 and includes the throttle 26 described above with reference to FIG. Furthermore, the control valve 19 on the spool 3 resists the force of the valve spring 19b slightly! When retracted, an oil passage hole 63 is completely drilled to communicate the outer circumferential space of the rond part +9a to the annular groove 37 connected to the drain boat 15T.

Neutral position N of flow rate control valve 19 and control valve 2
Since the unloading pulp 1'8 opens and unloads the bonder boat 15PLv oil pE at the lowering action position as described above, the position shown in FIGS. Do not perform any forward motion.

As shown in FIG. 8, the flow control valve 19 is actuated on the primary side through the oil passage 32 and the oil passage hole 61 in an oil field with respect to this LVc. to the position where the oil passage hole 63 is opened? Then I left work and performed two relief operations to release the oil to Drenbo [5T]. This l+ relief work is valve spring 19b
This is done against the force and against the action of hydraulic pressure through the variable restrictor 25 and restrictor 26 shown in FIG. The control valve 19 moves forward and backward so as to take a position corresponding to the oil pressure difference between the oil pressure acting on the next side and the oil pressure acting on the rear side, and changes and controls the opening degree of the oil passage hole 63 to control the lift cylinder. 8
The unload check valve 20, as shown in FIG. The rod portion 20ck is integrally formed with a groove bottom. A metal fitting 65 is placed in contact with the back of the piston 48, and the metal fitting 65 is placed in contact with a part of the outer end surface of the flange 52affi of the support cylinder 52 as shown in FIG. It is prevented from coming out.

By switching the oil path using the spool 3, the oil chamber 50 behind the piston 48 is brought into communication with the pump boat 15PK only at the downward operating position iRD of the control valve 2. Therefore, in the neutral position II N and the upward operating position +4 U of the control valve 2, as shown in FIG. When the button is in the closed state where the valve seat 20bK is seated by the force of the spring 20a, the piston 48 moves forward as shown in FIG. (Press to fully open the unload check valve 20. In other words, at the downward action position iF\D of the control valve 2, the unload pulp I8 opens as in the previous 2, but the relief Ff of this unload pulp I8 is 4tJ,\ !Approximately 5 ks /
cd K 2 is fixed, unload check valve 2
The load of the valve spring 20a at 0 is approximately 5 kg/cj above in addition to the cylinder boat 15C(1)AIIIE acting on the primary side of the check valve 20, and when fchFE acts on the piston 48, the unload check is performed. valve 2
0 is open'! It is because of the value that it is forced to make. Also, the oil chamber 50 behind the piston 48? The front two small-diameter oil passages 51 leading to the drain port 15T are formed as oil passages with a small inner diameter to allow hydraulic pressure to remain in the oil chamber 50 until the unload check valve 20 is opened.

As shown in FIG. 5, the Itle receiver has a dash bin 65a'ilf'7 attached to the hardware 65 that protrudes outside the pulp case.
By pressing 5at, the receiver pushes in the metal fitting 65 as shown by the plumb line in Fig. 10, thereby fully opening the unload check valve 20 through the piston 48, causing the lift cylinder 8 to perform a contracting operation and allowing the work Fs to fully lower the scales. It is said that

The first embodiment is constructed as described above and includes a control valve 2 and other pulps 17.18.
19.2 (The action of + is a far bend with its individual configuration.

t:+-)" Check valve 17V! Control valve 2
Neutral position rfl N 7C') Prevents backflow of oil from the lift cylinder 8 and securely holds the lift cylinder 8 in a stopped state. Even though the load check valve 17 is closed, the unload check valve 20, which opens at the downward operating position HD of the control valve 2, allows the lift cylinder 8 to contract. This unload check valve 20i is not directly opened by the spool 3, but in some cases, the load on the pulse motor 4 for displacing the spool 3 is increased.

The unloading pallet 7''18 unloads the hydraulic pressure of the pump discharge oil at the neutral position JN and the descending position +1'lD of the control valve 2, thereby reducing the energy consumption of the hydraulic pump IO. Action circuit 27
The rapid movement of the flow rate control valve 19 in the throttle 26 inside the throttle 26 completely prevents the generation of noise and the acceleration of wear.

The electric controller 59 is controlled sequentially according to a preset program based on the input of set values or detection signals, and generates all electric pulses. It is displaced by an amount consisting of WN in the direction of the upward working position NU or the downward working position rilD, and then returned to the neutral position rfjN.

11 to 14 show a second embodiment in which the present invention is implemented as a control valve system having the same purpose as the first embodiment, and FIG. 11 corresponds to FIG. 12.
Figures 13 and 14 correspond to Figures 8, 9, and 10, respectively. In this second embodiment, in addition to a flow rate control valve 19 similar to the one described above, a pilot valve 70 for opening an unload check valve 20 at the lowering position of the control valve 2 is provided in the hollow spool 8. This pilot valve 70 is unique in that it is operated by a rotary metal fitting 54 corresponding to the M rotary metal fitting 54 rotated by the pulp motor 4.

Structure The basic structure of the second embodiment is the same as that of the first embodiment, so the parts that are constructed in the same way or similar to the kanji character 1@inverted. will be referred to by the same reference numerals as used in the explanation of the first embodiment, and the explanation of fC will not be repeated.

2nd'-ii: In the #1 example, the sliding hardware 6 is formed to have a short length, and the inner end surfaces of the sliding hardware 6 and the rotating hardware 54 are aligned with each other at the neutral position of the spool 3 shown in FIG. They are located almost on the same plane. In addition, in the hollow part of the spool 3, on the sliding metal fitting 6 side of the flow control valve 19, displacement in the direction of the Fi moving metal fitting 6 is regulated by a snap ring 71 on the inner peripheral surface of the spool 3. 'fr: A oil-tight fit. This passage-forming metal fitting 72 has oil passage holes 72C in a radial direction that connect a through hole 72a extending along the axis thereof and an annular groove 72b on the outer circumferential surface. The annular groove 72b is formed in the spool 3 and extends 7' into the oil passage hole 73 and extends 1!I! into the annular groove 46 corresponding to the annular groove 46 in the first embodiment. The annular groove 46 is connected to the oil passage 49. A series 1 is provided behind the unload check valve 20 shown in Fig. 14.
0, no member corresponding to the piston 4BVC is provided, and n1c of the cylinder boat 15C is connected to the valve spring 2.
An oil passage hole is formed that includes all of the predetermined throttles 74 that act on the back of the valve 20, which is the IP part 0a.

At the end of the rod portion 19a of the flow rate control valve 19, another rounded portion 75 is formed completely integrally, and this rod portion 75 is completely penetrated through the through hole 72a of the metal fitting 72, and its tip faces the rotating metal fitting 54. Let me do it.

Rod portion 750 free ff1. ! The j side is formed into a bar with an outer diameter that fits tightly into the through hole 72a, and the boundary between the two round doors 19a and 75 is a valve seat formed with an oil passage forming metal fitting '72V at the end of the through hole 72a. The engageable poppet portion 76 is fitted with an IJZ. The length of the rod portion 75 is 100 mm when the pulp 2 is in the middle position shown in FIG. The length of the rod portion 75 is set such that the end face of the rod portion 75 is substantially in contact with the rotary metal fitting 54, and is divided into a vertical portion that engages with the valve seat.

The #1 pilot valve 70 has a valve body and a valve spring 19bt-a filter formed on the rod part 19a+75 of the flow rate control valve 19, and the rod gfl I9
(a) The outer peripheral space (tS) is optionally provided with a function of quickly lifting up behind the unload check valve 20. i.e. il
When the control valve 2 is in the neutral position shown in Fig. 1, the upper 2
As shown in the figure, the poppet portion 76 engages with the valve seat at the end of the through hole 72a, and the end of the hole 72a is locked.
In addition, at the rising operation position 1q of the control valve 2 shown in FIG. 12, the control valve I9 performs a relief operation, so the poppet portion 76 separates from the valve washer, but at that time, the large diameter portion of the rod portion 75 is connected to the oil passage. While the hole 72cii is blocked, in the lowering operation position of the control valve 2 shown in FIG. . At the lowering position of the upper tab 9, the sliding metal fitting 6 is displaced to the right in the figure by the pulse motor 4, and the spool 3 is correspondingly displaced in the same direction VC by the spring 7, thereby controlling the flow rate. Valve 19 and its rod part! 9a and 75 also try to follow the displacement of the valve spring 19b due to the force of the valve spring 19b, whereas the rotating hardware 54 does not change its position; the force 1 pushes the rod part 75 to the left in the figure, and for this reason The poppet part 76 is the through hole 72
Leaving the valve seat at end a, the outer circumferential space of the rond part 19a penetrates.
so as to be communicated to the back of the check valve 20,
It is planned.

Effect The second embodiment operates differently from the first embodiment only in the following points, and other effects H"l<qualitatively the first
This is no different from the embodiment.

That is, the anorode check valve 2 in the second embodiment
(l fi control valve 2's neutral position and rising position r are received as 411 back pressure of cylinder boat 15C via M path including specified throttle 74, and this back pressure and valve spring 2 (la force) Then, maintain the closed state where the valve is seated on the valve seat as shown by the chain line in Figure 14.

Is control valve 2 in neutral position n? When t is moved to the lowering position, it is recorded as 7? +Pilot valve 70
is the outer peripheral space care 70- of the rod portion 19a of the flow control valve 19.
It communicates with the back of the check valve 20. The outer peripheral space of the wood portion 19a is communicated with the pump boat 15P as in the first embodiment, but when the control valve 2 is in the lowering position, the unloaded pulp 18 is closed as shown by the chain line in FIG. Since it is transferred from the neck to the ill release neck shown by the solid line, the outer circumferential space of the rondo part +9a is connected to the pump boat 15P along with the drain bow h l 5 T,
Therefore, the back of the unload check valve 20 is also connected to the drain boat 15T. At this time, the back of the unload check valve 20 is also connected to the cylinder boat 15C, but since there is a drain shifter 4 in the communication path, the drain boat +5T2 is connected from behind the unload check valve 20. Heto 7 [f
Therefore, the unload check valve 20 is operated by the cylinder boat 1 that acts on the Moemen Tsukuda 1.
5cc/) oil pressure, valve 19 resists the force of spring 2()a, opens as shown by the arrow in FIG. 14, and opens cylinder boat 15C.
Drain MJ completely from drain boat 15 T.

The above-described embodiments 7'c2 are all related to this invention as a control valve device for a hydraulic lift device installed in a tractor, but this invention is of course also applicable to the invention as described at the beginning. The present invention can be implemented as a control valve device for controlling the displacement of agricultural working machines for various purposes.

Also, in the illustrated embodiment, in accordance with one embodiment of the present invention,
Seven-pulse motor 4 only allows sliding displacement in one direction of spool 3
Then, slide the spool 3 in the other direction (IJ
A structure in which the displacement is performed behind the spring 7 has been adopted, but with this structure, compared to a structure in which the spool 3 and the sliding metal 6 are manufactured integrally and are slidably displaced as one, processing is easier. It is advantageous in that it is easy to maintain the motor 4 and the spool 3 can be left behind when the pulse motor 4 breaks down, making maintenance easier. Of course, it is also possible to adopt a structure in which the sliding displacement in both directions is directly controlled by the pulse motor.

Furthermore, as the motion conversion mechanism 5 for converting rotational motion into linear motion, one feed screw was used in the embodiment, but many mechanisms are well known as this type of motion conversion mechanism (for example, reeds). Written by Ye Qing Sanbu, “Whispers Machine Lun!lI[+J4J,
(Gihodo Co., Ltd., March 15, 1962, 10th edition, pp. 19-87), an appropriate one can be selected and adopted from among these well-known methods.

The sliding displacement of the spool 3 for switching the oil path is controlled by the pulse motor 4.
According to the present invention, in contrast to the conventional system in which the sliding displacement of the spool is obtained by a full link mechanism, the complicated 81-ton link mechanism is omitted, and the connection points between link elements are eliminated. Not only does the accuracy of spool displacement control improve as there is no decrease in accuracy due to play, but the use of a pulse motor that is fully controlled by electric pulses provides much more responsiveness than mechanical ones. Good spool displacement control can be performed.

Whereas the magnetic control valve allows the spool to be displaced instantaneously and there is no possibility of changing the spool displacement speed each time or over time, this invention According to VC, it is possible to freely change the displacement speed of the spool by changing the pulse interval given to the pulse motor, making it possible to displace agricultural working machines with large inertia without shock. While it is difficult to produce,
The valve system of the present invention, in which the spool is completely submerged and is slidably displaced by a pulse motor, can control 4 or more positions without the spool displacement mechanism imposing any restrictions on increasing the position of the spool or control valve. It is easy to manufacture one with a valve.

4. Explanation of 1mg4 in Figure 1 Figure 1 is a circuit diagram of an oil field circuit including the first embodiment of the present invention, Figure 2 is a plan view of the first embodiment, and Figure 3 is a diagram showing @. The m-m arrow view, FIG. 4, and FIG. 5 are longitudinal sections taken along the IV-ff line and the V-V line in FIG. ■An arrow view, a longitudinal cross-sectional view along the ■-■ line in Fig. 4, Figs. Figure 1O is the same longitudinal sectional side view as Figure 5, but it is completely shown in a different state, Figure d'l1,
FIGS. 12 and 13 are longitudinal side views showing the second embodiment of the present invention at different angles, and FIG. FIG.

■...Control valve device, 2...':y nt a-le pulp, 3...Spool, 4...Pulse motor, 4a...Motor shaft, 5...Motion conversion F14
m, 6... Suri TIja modern item, 6a... Annular step, 6
b...internal thread, 6 c..., long slotted hole, 7... tin ring, 52... support cylinder, 53... threaded pin, 54... rotating hardware, 54a... outside Screw, 55...
・Pin, 56...Snap ring, 57...Spring retainer ring.

Figure 1 Figure 6 Figure 7 Figure 7 sTs Procedural amendment (method) September 1985-27 1988 Patent Application No. 94049 2 Masterpiece of invention Control valve device for agricultural working machine displacement control 3 , Relationship with the case of the person making the amendment Patent applicant representative Koji Yamaoka Department 4, Attorney 6 Number of inventions increased by amendment E! "Agricultural working machine...valve device" in the 3rd line of page 1 of the A specification is corrected to "control valve device for agricultural working machine displacement control."

(that's all)

Claims (2)

[Claims] 1. A control valve device for controlling the displacement of an agricultural working machine, in which a control valve for switching an oil path is configured as a spool valve, and the control valve device is interlocked with the spool of the spool valve through a motion conversion mechanism that converts rotational motion into linear motion. A control valve device characterized in that a connected pulse motor is provided, and the spool is slidably displaced by rotation of the pulse motor. 2. A control valve device for controlling the displacement of an agricultural working machine according to claim 1, wherein a sliding metal member that is driven forward and backward by the pulse motor via the motion conversion mechanism is disposed opposite to one end of the spool. A control valve device characterized in that a spring is disposed at the other end of the spool to urge the one end of the spool to slide in a direction to engage the sliding metal fitting.