JPH0114085Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a posture control device for maintaining the horizontal posture of a ground work device such as a rotary tiller that is towed by a tractor to perform field cultivation work.
It is related to

When a ground work device such as a rotary cultivator, which is connected to this machine such as a tractor and is raised and lowered by a hydraulic lift cylinder, is used for ground work such as plowing in a lower working position that acts on the field, the ground work device is connected to this machine. When tilting to follow the slope of the machine, it is not possible to obtain consistent work results such as a constant plowing depth. Therefore, a posture control device such as the one described above is installed, so that even if the machine is tilted, the ground work equipment will not work. has already been maintained in a horizontal position.

This type of attitude control device is equipped with an attitude control hydraulic cylinder that changes the attitude of the ground work equipment, and the attitude control hydraulic pressure is controlled by a solenoid valve whose position is switched and controlled by a sensor that detects the attitude of the ground work equipment. The ground working device is configured to maintain the ground working device in a horizontal position by controlling the supply of hydraulic oil to the cylinder. Generally, the hydraulic pump for supplying hydraulic oil to the above-mentioned attitude control hydraulic cylinder is also used as a hydraulic pump for supplying hydraulic oil to the hydraulic lift cylinder for raising and lowering the ground work equipment. The hydraulic oil is supplied to the hydraulic lift cylinder and the attitude control hydraulic cylinder by a single hydraulic pump, and the discharge flow of the pump is distributed to the hydraulic lift cylinder and the attitude control hydraulic cylinder via a flow dividing valve. In addition, in order to be able to change and adjust the attitude correction speed of the working equipment by the attitude control hydraulic cylinders, the above-mentioned flow divider valve changes and adjusts the supply ratio of hydraulic oil to each of the above-mentioned hydraulic cylinders. Configured into a possible valve.

By the way, conventionally, in order to relatively increase the attitude correction speed of the ground work equipment by the attitude control hydraulic cylinder, the above-mentioned flow divider valve was used to increase the proportion of hydraulic fluid supplied toward the attitude control hydraulic cylinder. When making adjustments and proceeding with work, the following problems were observed.

In other words, when turning the machine on a headland in a field, the ground work device is lifted upward to the standby position by the hydraulic lift cylinder, but as mentioned above, the flow control valve operates in the direction of the attitude control hydraulic cylinder. When the oil supply ratio is increased, the hydraulic oil supply ratio in the direction of the hydraulic lift cylinder is correspondingly smaller, so that the hydraulic lift cylinder can be quickly extended, that is, the ground work equipment can be quickly moved by the lift cylinder. As a result, work efficiency was reduced due to the lack of improvement.

The purpose of this invention is to solve the problems described above in a structure in which hydraulic oil is supplied to a hydraulic lift cylinder and an attitude control hydraulic cylinder by a single hydraulic pump via a flow dividing valve as described above. An object of the present invention is to provide a new attitude control device for a ground work device that solves the problem.

Regarding the illustrated embodiment, the structure of this invention will be explained. In Fig. 1, 1 is an agricultural tractor, and a rotary tiller 2, which is an example of a ground work device, is connected to the rear of the tractor 1 to be pulled. There is. As usual, this connection is made using one upper link 3 and two left and right lower links 4, and the left and right lift arms 6 of a hydraulic lift device 5 installed at the top of the rear of the tractor 1 are connected. It is connected to the left and right lower links 4 by left and right tie rods 7, and the rotary tiller 2 can be raised and lowered by a hydraulic lift cylinder 8 (FIG. 2) of a hydraulic lift device 5. An attitude control hydraulic cylinder 9 is inserted into the tie rod 7 on one side, and changes the attitude of the rotary tiller 2 by expanding and contracting the tie rod 7. Further, a sensor 10 such as a mercury switch is provided on the rotary tiller 2 to detect the attitude of the tiller 2. In FIG. 1, 11 is a PTO shaft extending rearward from the tractor 1, and 12 is a flexible transmission shaft mechanism for transmitting driving force from the PTO shaft 11 to the rotary tiller 2.

A hydraulic circuit as shown in FIG. 2 is provided in order to correct the attitude of the rotary tiller 2 by expanding and contracting the attitude control hydraulic cylinder 9 when the rotary tiller 2 is tilted from side to side. . As shown in the figure, a control valve device 1 for the hydraulic lift cylinder 8 is operated by a hydraulic pump 14 from an oil tank 13.
An oil supply circuit 17 for the attitude control hydraulic cylinder 9 is provided branching off from an oil supply circuit 16 for the hydraulic lift cylinder 8 that supplies hydraulic oil to the primary side of the hydraulic lift cylinder 8 and the attitude control oil supply circuit 17. Hydraulic oil is supplied to the hydraulic cylinders 9 and 9 by a single hydraulic pump 14. At the branch part of both the above-mentioned oil supply circuits 16 and 17, the oil supply circuit 1
7 and a relief valve 19 which is inserted into the oil supply circuit 16 and uses the oil pressure of the oil supply circuit 17 on the secondary side of the variable throttle 18 as back pressure. valve 20
However, it is provided.

In order to selectively operate the attitude control hydraulic cylinder 9, a solenoid valve 21 is provided, which has a primary side pump port 21P connected to the oil supply circuit 17, as shown in FIG. The tank port 21T on the primary side of this solenoid valve 21 is connected to the oil drain circuit 2.
2 to the oil tank 13, and two cylinder ports 21C _a on the secondary side of the solenoid valve 21,
_21Cb is connected to the expansion oil chamber 9a and the contraction oil chamber 9b of the attitude control hydraulic cylinder 9 through supply/discharge circuits 23A and 23B, respectively. The solenoid valve 21 has three positions, and at the neutral position N shown in the figure, both cylinder ports 21C _a , 2
1c _b to stop the attitude control hydraulic cylinder 9, communicate between the pump port 21P and the tank port 21T, and also block the solenoid 21A.
At the working position _A , which is moved by the excitation _of
In the other operating position B, which is moved by the excitation of the other solenoid 21B, the pump port 21P and the cylinder port 21C _b are communicated, and the cylinder port 21C _a and the tank port 21T are communicated to control the posture. Hydraulic cylinder 9
It is configured to operate in a reduced manner. As usual, each of the solenoids 21A and 21B described above is selectively energized when the sensor 10 detects an inclination of the rotary tiller 2 in one direction or the other. .

Similarly, as shown in FIG. 2, in accordance with this invention, a regulator valve 24 as described below is inserted and installed in the oil supply circuit 17. That is, the regulator valve 24 has two positions: a first position where the internal throttle 25 throttles the oil supply circuit 17 to reduce the amount of oil supplied in the direction of the attitude control hydraulic cylinder 9; and a second position where the amount of oil supplied is increased without throttling.

The regulator valve 24 is moved between the first position and the second position.
In order to selectively displace between the positions of
The following means are provided: That is, first, the regulator valve 24 is operated as shown in FIG.
It is biased toward the first position by the spring 26, and normally assumes the first position. and the spring 26 of the valve 24
The working end is connected to the oil drain circuit 2 by a drain circuit 27.
2, and the other end is connected to the oil supply circuit 17 on the secondary side of the valve 24 by a pilot hydraulic action circuit 28. When oil pressure is established in the oil supply circuit 17, the oil pressure acts against the force of the spring 26. Second
It is assumed that the vehicle is moved to the position of .

Therefore, when the solenoid valve 21 is in the neutral position N, the oil supply circuit 17 is connected to the oil drain circuit 22, and no oil pressure is established in the oil supply circuit 17, the regulator valve 24 is operated by the spring 26. 1st
The solenoid valve 21 is moved to either operating position A or B, and the oil supply circuit 17 is connected to the supply/discharge circuit 23A or 23B, and hydraulic pressure is established in the oil supply circuit 17 to maintain the posture. When the control hydraulic cylinder 9 is operated, the regulator valve 24
is displaced to the second position by hydraulic action. That is, the solenoid valve 21 is moved to each operating position A or B to establish oil pressure in the oil supply circuit 17, thereby controlling the attitude control hydraulic cylinder 9.
The spring 26 and the pilot hydraulic action circuit 28 constitute a means for displacing the regulator valve 24, and the displacement means is configured to detect when hydraulic pressure is established in the oil supply circuit 17. By doing so, the regulator valve 24 is displaced to the second position only when the operation of the attitude control hydraulic cylinder 9 is detected.

As shown in FIG. 2, a throttle 30 is inserted into the primary pressure acting circuit for the relief valve 19, so that the flow dividing ratio of the two oil supply circuits 16 and 17 is controlled to be changed rapidly by the flow dividing valve 20. Efforts have been made to ensure that this does not occur. 31,3 in Figure 2
Reference numeral 2 denotes a throttle and a check valve which are connected in parallel and inserted into the supply/discharge circuit 23A. During the extension operation of the cylinder 9, hydraulic oil is slowly supplied to the extension oil chamber 9a through the throttle 31 to avoid a sudden descent of one end of the rotary tiller 2, and when the posture control hydraulic cylinder 9 is retracted, the hydraulic oil is supplied slowly to the extension oil chamber 9a. Extension oil chamber 9 via stop valve 32
to drain oil relatively quickly from a.
There is a plan. Reference numeral 33 denotes a check valve inserted into the supply/discharge circuit 23B, which prevents oil from flowing backward from the reduction oil chamber 9b due to the weight of the rotary tiller. To,
The electromagnetic valve 21 is configured to be opened when moved to the operating position A. In addition, in FIG. 2, 34 is a pressure regulating valve for setting the oil pressure.

The diversion valve 20, solenoid valve 21, regulator valve 24, throttle 31, and check valve 32 described above,
33 is unitized as an attitude control valve device 35, as shown surrounded by a two-dot chain line in FIG. As shown in FIG. 3, such an attitude control valve device 35 is placed behind the driver's seat 36 of the tractor 1 in a position sandwiched between the left and right lift arms 6 mentioned above, and is mounted on the upper surface of the tractor 1 body. is set up. In FIG. 3, 37P indicates the attitude control valve device 3 from inside the housing of the hydraulic lift device 5.
5, 37C is an oil pipe that leads oil from the attitude control valve device 35 to the control valve device 15 (FIG. 2) in the housing, and 37T is drain oil from the attitude control valve device 35. Oil pipes 37A and 37B that return the oil into the tractor body housing which also serves as the oil tank 13 are a pair of flexible oil pipes that connect between the attitude control valve device 35 and the attitude control hydraulic cylinder 9.

Next, the specific structure of the attitude control valve device 35 described above will be explained with reference to FIGS. 4-11.

As shown in FIGS. 4 and 5, the solenoid valve 21 is formed separately from a valve case 38 in which other valves of the attitude control valve device 35 are housed,
The case 38 is installed on the top surface of the valve case 38.
It is fixed by a fixing member 39. As clearly shown in FIGS. 7 and 10, the valve case 38 includes the four ports 21P and 21 of the solenoid valve 21.
Four oil passages 40P, 40T, 40C _a , which are connected to T, 21C _a , 21C _b (Fig. 2), respectively.
40C _b is drilled.

The valve case 38 includes the five oil pipes 37P, 37C, 37T, 37A, and 37B (third
Figure) Five ports connected to each end, that is, a pump port 41P and a diversion port 41C,
Tank port 41T and two cylinder ports 4
1A and 41B are provided. Of these, the pump port 41P is opened on one side of the valve case 38 as shown in FIG. 4, and the cylinder port 41A is opened on the other end surface of the valve case 38 as shown in FIGS. be. The other three ports are branch port 41C and tank port 41
T and the cylinder port 41B are each opened at the lower surface of the valve case 38, as clearly shown in FIG.

The valve case 38 has an oil passage 42 in the vertical direction, an oil passage 43 in the front-rear direction, and an oil passage 43 in the left-right direction in order to communicate the pump port 41P with the oil passage 40P connected to the pump port 21P of the solenoid valve 21. A passage 44, an oil passage 45 in the vertical direction, and an oil passage 46 in the front and back direction are bored, of which the oil passages 44 and 45 are connected to the regulator as shown in FIGS. They are respectively opened to the hole valves for the valves 24, and the oil passages 46 and the oil passages 4
0P is opened to the hole valve for the relief valve 19, as shown in FIGS. 4 and 5.

The variable diaphragm 18, as shown in FIGS. 6 and 9,
It is also constituted by a threaded rod that is screwed into the valve case 38 with its tapered end facing into the oil passage 43. A handle 18a is attached to the screw rod constituting the variable throttle 18 outside the valve case 38 for changing and adjusting the degree of restriction of the oil passage 43 by the variable throttle 18 by rotating the screw rod.

As shown in FIG. 4, the relief valve 19 includes the oil passage 42 connected to the pump port 41P and the vertical oil passage 47 bored in the valve case 38 connected to the branch port 41C. They are inserted into valve holes that are opened at appropriate intervals. The throttle 30 is formed by a throttle-forming metal fitting 30a screwed onto the tip of the relief valve 19. The valve spring 19a of the relief valve 19 is provided so that its base end is received by a screw plug 48 that closes one end of the valve hole. The oil passage 46 opens into the valve hole behind the relief valve 19, so that the hydraulic pressure on the secondary side of the variable throttle 18 acts as back pressure on the relief valve 19 as described above. It's summery. The relief valve 19 is provided with an oil passage hole 19b for communicating between the oil passages 46 and 40P through the valve hole. Further, the relief valve 19 is provided with oil which, when the relief valve 19 is moved back by an amount δ from the position shown in FIG. Passage hole 1
9c is provided.

The diverting valve 20 is composed of a combination of a variable throttle 18 and a relief valve 19. When the oil pressure difference between the primary side oil pressure and the secondary side oil pressure of the variable throttle 18 changes, the relief valve 19 slides and displaces the oil passage. By changing and controlling the oil flow area between 42 and 47 so that the above-mentioned oil pressure difference is kept constant, the ratio of the oil flow rate flowing to the branch port 41C and the oil flow rate flowing to the oil passage 40 becomes constant. Then, the flow rate is controlled. The oil flow rate ratio can be adjusted by operating the handle 18a.
The adjustment is made by changing the degree of restriction of the oil passage 43 by 8.

Next, as shown in FIGS. 5, 6, and 9, the regulator valve 24 is inserted into a valve hole in which the oil passages 44 and 45 are opened with an appropriate interval between them. , the first shown in FIG.
An oil passage hole 24a for communicating between the oil passages 44 and 45 is provided at a position, and the throttle 25 is provided by a throttle-forming hardware fixedly installed in the oil passage hole 24a. has been done.
The regulator valve 24 has a first position shown in FIGS. 5 and 6 which blocks the oil passages 44 and 45, and a second position shown in FIG. A land 24b is provided with a space between them to allow communication without using the aperture 25. The spring 26 is provided so that its base end is received by a screw plug 49 that closes the end of the valve hole of the regulator valve 24 . The spring 26
Inside the valve hole on the opposite side is the oil passage 40P, and a left-right oil passage 50 bored in the valve case 38.
(Fig. 4 is clear) are communicated via an oil passage 51 in the vertical direction and an oil passage 52 at the end of the valve hole,
The pilot hydraulic circuit 28 previously described in connection with FIG. 2 is provided by the oil passages 50, 51, 52. Tank port 21T of solenoid valve 21
(Fig. 2) is connected to the tank port 41T as shown in Fig. 8, and the oil passage 40T connected to the oil passage 40T in the left and right direction is connected to the tank port 41T as shown in Fig. 8. An oil passage 54 in both directions is bored in the valve case 38, and the oil passage 54 opens into the spring 26 installation space as shown in FIGS. Therefore, due to the oil passages 54 and 53,
A drain circuit 27 is provided as previously described with respect to FIG.

Accordingly, the regulator valve 24 and the means for displacing the valve 24 between the first position and the second position are as described above with respect to FIG. , when the solenoid valve 21 is in the neutral position N and no oil pressure is established in the oil passage 40P, the regulator valve 24 assumes the first position shown in FIGS. 5 and 6 by the action of the spring 26, Oil is supplied to the oil passage 40P via the throttle 25 at a small rate. Then, when the solenoid valve 21 is moved to either operating position A or B, the oil pressure established in the oil passage 40P is transferred to the oil passage 50,
By acting on the regulator valve 24 from the opposite side of the spring 26 through 51 and 52, the regulator valve 24 is moved to the second position shown in FIG. On the other hand, oil is supplied at a relatively high rate determined by the degree of restriction of the variable throttle 18.

Next, the cylinder port 21C _a , 2 of the solenoid valve 21
1C _b and the cylinder _{ports 41A} , 4 of the valve case 38.
1B will be explained with reference to FIGS. 7 and 10. A hole 54 formed in the valve case 38 and arranged concentrically with the cylinder port 41A is connected to an oil passage 55 along the front-rear direction. It communicates with the oil passage 40C _a . Further, a hole 56 formed in the valve case 38 and arranged concentrically with the hole 54 described above is communicated with the cylinder port 41C _b by an oil passage 57 along the vertical direction, and is connected to the oil passage 58 along the front-rear direction in the left-right direction. It is communicated with the oil passage _40Cb by an oil passage 59 extending therethrough.

The above-described check valve 32 is slidably disposed within a port-forming metal fitting 60 that is screwed onto the valve case 38 at the end of the hole 54, and the throttle 31 is formed in the check valve 32. . Inside the hole 54 is a sliding metal fitting 6.
This sliding metal fitting 61 is provided with an oil passage hole 61a for communicating the oil passage 55 with the cylinder port 41A. An annular groove 60a is formed on the inner circumferential surface of the distal end of the port forming hardware 60, and a first annular groove 60a is formed on the distal end surface of the check valve 32.
When the slit 32a is formed as clearly shown in FIG. 1 and the check valve 32 is displaced toward the distal end inside the port forming hardware 60 as shown in FIG. The oil passage hole 32b in 32 is communicated with the oil passage hole 61a of the sliding metal fitting 61 via the annular groove 60a and the slit 32a, and conversely, as shown in FIG. When the port forming hardware 60 is displaced toward the proximal end side, the end of the oil passage hole 32b is blocked by the inner circumferential surface of the port forming hardware 60, so that the oil passage hole 32b is opened only through the throttle 31. hole 61
It is designed to communicate with a.

The above-mentioned check valve 33 is inserted into the hole 56 and is seated on a valve seat 62 in the middle of the hole 56 by the force of a spring 63 to prevent backflow of oil from the direction of the cylinder port 41B. The hole 64 that connects the holes 54 and 56 is the valve case 3.
8, and the check valve 33 has a hole 6 formed therein.
A slit 33b is formed in the slit 33a to communicate the hole 56 with the hole 54 at the tip of the sliding metal fitting 61. be. The length of the rod portion 33a is such that when the check valve 33 is seated on the valve seat 62 as shown in FIG. It is set.

As described above, the throttle 31, the check valve 32, and the check valve 33
They are said to function in the following way. That is, when the solenoid valve 21 is moved to the operating position A and hydraulic pressure is applied to the distal end surface of the check valve 32 through the oil passages 40C _a and 55 and the oil passage hole 61a, as shown in FIG. The check valve 32 is displaced toward the proximal end within the port forming hardware 60 by the oil pressure, and at this time, as described above, the oil passage holes 61a and 32b are communicated only through the throttle 31. Hydraulic oil is supplied to the cylinder port 41A through the throttle 31. In addition, as mentioned above, at the operating position A of the solenoid valve 21, the hydraulic pressure acts into the oil passage hole 61a.
Similarly, as shown in FIG. 10, the sliding metal fitting 61 is slid to the innermost part of the hole 54 by hydraulic action,
As a result, the rod portion 33a is pushed, and the check valve 3
3 is opened by leaving the valve seat 62 against the force of the spring 63, and the oil passage 57, the hole 56, and the oil passages 58, 59, 40 are opened from the cylinder port 41B.
Oil drains through C _b .

Conversely, the solenoid valve 21 is moved to the operating position B, and the oil passage 4
0C _b , 59, 58 and the check valve 33 through the hole 56
When hydraulic pressure is applied to the tip surface of the seventh
Since the check valve 33 is opened by the oil pressure as shown by the chain line in the figure, the oil passage 57 is further opened from the hole 56.
Hydraulic oil is supplied to the cylinder port 41B via the cylinder port 41B. When the solenoid valve 21 is moved to the operating position B as described above, the hole 54 and the oil passage 55,
40C _a connects to tank port 41T via solenoid valve 21
On the other hand, since hydraulic pressure is applied to the tip end surface of the sliding metal fitting 61 from inside the hole 56 through the slit 33b, the sliding metal fitting 61 is connected to the sliding metal fitting 61 by the hydraulic action as shown in FIG. is displaced in the direction of the port-forming hardware 60 until it comes into contact with the inner end surface 60b of the port-forming hardware 60. and check valve 32
is pushed by the drain oil flow from the cylinder port 41A due to the oil pressure difference before and after the throttle 31, and is displaced toward the tip side in the port forming metal fitting 60, where the tip surface hits the sliding metal fitting 61 as shown in FIG. At this time, since the oil passage hole 32b is communicated with the oil passage hole 61a via the annular groove 60b and the slit 32a as described above, the oil flows from the cylinder port 41A to the oil passage 55 without being throttled by the throttle 31.
40C Drained in direction _a .

As described above, the throttle 31, check valve 32, and check valve 33 are as described above with reference to FIG.

In addition, in FIG. 4, 66 is the valve case 38.
This is an insertion hole for a fixture for fixedly connecting the hydraulic lift device 5 to the housing of the hydraulic lift device 5.

The attitude control device shown in FIG. 1-11 is configured as explained above, so that when the sensor 10 detects the left and right inclination of the rotary tiller 2, the attitude control device shown in FIG. Depending on the direction, the solenoid valve 21 is moved to either the operating position A or B, and at that time, the regulator valve 24 is automatically displaced to the second position as described above, and the oil supply circuit 17 is moved. Hydraulic oil is supplied through the solenoid valve 21 in the direction of the solenoid valve 21 at a rate determined by the degree of restriction of the variable throttle 18. Then, such hydraulic oil is supplied to the attitude control hydraulic cylinder 9 via either the supply/discharge circuit 23A or 23B, and the operation of the hydraulic cylinder 9 causes the rotary tiller to move in the direction of eliminating the above-mentioned inclination. The posture of 2 is corrected.
By inserting the throttle 31 into the supply/discharge circuit 23A, as described above, the proportion of hydraulic oil supplied to the extension oil chamber 9a of the posture control hydraulic cylinder 9 is reduced, and the rotary tiller 2 Sudden descent of the one end side and generation of impact force due to such descent are therefore prevented.

As described above, the regulator valve 24 assumes the first position at the neutral position N of the solenoid valve 21, and at that time the internal throttle 25 throttles the flow rate of the hydraulic oil flowing through the oil supply circuit 17. The following advantages can be obtained. That is, the variable aperture 18
Even if the solenoid valve 21 is in the neutral position N even when the work is progressing by making the degree of restriction of the valve relatively small and increasing the proportion of hydraulic oil supplied to the hydraulic cylinder 9 when the attitude control hydraulic cylinder 9 is activated. As long as the oil flow rate in the oil supply circuit 17 is regulated by the throttle 25 and kept extremely small, the hydraulic lift cylinder 8
A large amount of oil is secured in the oil supply circuit 16 in the direction by moving the relief valve 19 significantly to the right in the figure from the position shown in FIG. Therefore, for example, when turning the tractor 1 on a headland in a field, the control valve device 15 is operated to extend the hydraulic lift cylinder 8 to lift the rotary tiller 2. A quick extension motion and therefore a quick upward motion of the rotary tiller 2 can be obtained. In other words, although the hydraulic pump 14 is used both for the hydraulic lift cylinder 8 and for the attitude control hydraulic cylinder 9, the proportion of hydraulic oil supplied to the hydraulic lift cylinder 8 is relatively greatly reduced, and the hydraulic pump 14 can be used for both the hydraulic lift cylinder 8 and the attitude control hydraulic cylinder 9. This prevents a situation in which the cultivator 2 cannot move upwardly, resulting in a decrease in work efficiency.

Next, another embodiment shown in FIGS. 12 and 13 will be described. In this other embodiment, the regulator valve 24 having the same position as described above is placed in the first position.
As shown in FIG. 2, the electromagnetic valve is configured to normally take the same first position as described above under the force of a spring 70, and take the same second position as described above when the solenoid 71 is energized.

As shown in FIG. 13, the sensor 1
0 is equipped with a sensor switch 10A that detects the tilt of the rotary tiller 2 in one direction and a sensor switch 10B that detects the tilt of the rotary tiller 2 in the other direction,
The electric control circuit is configured such that one solenoid 21A of the solenoid valve 21 is energized by the ON operation of the sensor switch 10A, and the other solenoid 21B of the solenoid valve 21 is energized by the ON operation of the sensor switch 10B. On the other hand, the solenoid 71 of the regulator valve 24 is connected to either the sensor switch 10A or 1.
So that it can be excited even when 0B turns on,
It is connected in series to both sensor switches 10A and 10B and inserted into the electrical control circuit.

Therefore, in the embodiment shown in FIGS. 12 and 13, the operation of the attitude control hydraulic cylinder 9 is detected by the sensor switches 10A and 10B, and upon this detection, the solenoid 71 activates the regulator valve 24.
is displaced to the second position, providing advantages similar to those described for the previous embodiment.

As is clear from the description of the above two embodiments, the posture control device for a ground work device of this invention includes a posture control hydraulic cylinder 9 that changes the posture of the ground work device 2 which is raised and lowered by a hydraulic lift cylinder 8. A single hydraulic pump 14 supplies hydraulic oil to the hydraulic lift cylinder 8 and the attitude control hydraulic cylinder 9, and each hydraulic cylinder 8,
The sensor 1 is configured to supply the hydraulic oil to the ground work device 2 through a diversion valve 20 that can change and adjust the supply ratio of the hydraulic oil to the ground working device 2 .
An attitude control device configured to maintain the ground work device 2 in a horizontal attitude by controlling the supply of hydraulic oil to the attitude control hydraulic cylinder 9 by an electromagnetic valve 21 whose position is switched and controlled by 0. The oil supply circuit 1 for the attitude control hydraulic cylinder 9
A regulator valve 24 having a first position for reducing the amount of oil supplied in the direction of the attitude control hydraulic cylinder 9 and a second position for increasing the amount of oil supplied is inserted and installed in the position control hydraulic cylinder 7. Detection means for detecting the operation of the attitude control hydraulic cylinder 9 (in the embodiment shown in FIGS. 1-11, a solenoid valve 21 that detects the operation by establishing oil pressure in the oil supply circuit 17).
In the embodiment shown in FIGS. 12 and 13, a sensor switch 10 displaces a solenoid valve 21 into operating positions A and B.
A, 10B. ) and a displacement means (in the embodiment shown in FIG. 1-11, a spring 26) whose operation is controlled by the detection means to displace the regulator valve.
and the pilot hydraulic operating circuit 28. In the embodiment shown in FIGS. 12 and 13, the spring 70 and the solenoid 7
1. ), and is configured to displace the regulator valve to the second position only when the attitude control hydraulic cylinder 9 is activated, and has the following advantages. ing.

In other words, the attitude control device of this invention has a structure in which hydraulic oil is supplied to the hydraulic lift cylinder 8 and the attitude control hydraulic cylinder 9 by a single hydraulic pump 14 via the above-mentioned diversion valve 20. However, since the regulator valve 24 as described above is inserted and installed in the oil supply circuit 17 for the attitude control hydraulic cylinder 9, the solenoid valve 21 is in the neutral position N and the attitude When the control hydraulic cylinder 9 is not operated, the regulator valve 24 assumes the first position,
The amount of oil flowing through the oil supply circuit 17 is reduced, and on the contrary, the amount of oil supplied in the direction of the hydraulic lift cylinder 8 is increased. Even if the hydraulic lift cylinder 8 is adjusted so as to do so, the hydraulic lift cylinder 8 is caused to quickly extend. Therefore, when turning the machine 1 on a headland in a field, the ground working device 2 is lifted by the hydraulic lift cylinder 8, whereas the attitude control device of this invention can quickly lift the ground working device 2. This eliminates the problem of deterioration of work efficiency due to the time it takes to lift the work device 2, and improves work efficiency. When the attitude of the ground work device 2 is corrected by the operation of the attitude control hydraulic cylinder 9, the regulator valve 24 is automatically moved to the second position upon detection of the operation of the cylinder 9. Hydraulic cylinder 9 for attitude control according to the setting ratio to valve 20
Although the attitude control device of this invention has the above-mentioned advantages,
The posture of the ground work device 2 is corrected in a manner set in advance by the flow dividing valve 20, so that problems in posture correction do not occur.

[Brief explanation of the drawing]

Figure 1 is a side view of the rear of a tractor equipped with an embodiment of this invention and a rotary tiller, Figure 2 is a hydraulic circuit diagram of the same embodiment, Figure 3 is a schematic plan view of the rear of the tractor, and Figure 4. 5 is a partially longitudinal side view taken along the line V-V in FIG. 4, and FIGS. Figure 8 is an end view taken along the arrow in Figure 4.
10 and 10 are cross-sectional views similar to FIGS. 6 and 7, respectively, but taken in different states, FIG. 11 is an enlarged perspective view of a part of the same embodiment, and FIG.
The figure is a hydraulic circuit diagram showing another embodiment of this invention, and FIG. 13 is an electrical control circuit diagram of another embodiment. 1...Tractor, 2...Rotary tiller, 5...
...Hydraulic lift device, 6...Lift arm, 7...
Tie rod, 8... Hydraulic lift cylinder, 9...
Attitude control hydraulic cylinder, 9a... Extension oil chamber, 9b... Reduction oil chamber, 10... Sensor,
10A, 10B...sensor switch, 14...
Hydraulic pump, 15...control valve device,
16... Refueling circuit, 17... Refueling circuit, 18...
Variable throttle, 18a... Handle, 19... Relief valve, 20... Diversion valve, 21... Solenoid valve, 21
A, 21B... Solenoid, 22... Oil drain circuit,
23A, 23B... Supply/discharge circuit, 24... Regulator valve, 25... Throttle, 26... Spring, 27... Drain circuit, 28... Pilot hydraulic action circuit, 35... Attitude control valve device, 4
0P, 40T, 40C _a , 40C _b ...Oil passage, 4
1P...Pump port, 41C...Diversion port,
41T...Tank port, 41A, 41B...Cylinder port, 70...Spring, 71...Solenoid.

Claims (1)

[Scope of utility model registration request] A posture control hydraulic cylinder is provided to change the posture of a ground work device that is raised and lowered by a hydraulic lift cylinder, and a single hydraulic pump supplies hydraulic oil to the hydraulic lift cylinder and the posture control hydraulic cylinder, and a single hydraulic pump supplies hydraulic oil to each of the hydraulic cylinders. The system is configured to supply hydraulic oil through a diversion valve that can change and adjust the supply ratio of hydraulic oil to the ground work equipment, and a solenoid valve whose position is switched and controlled by a sensor that detects the attitude of the ground work equipment to control the attitude control hydraulic pressure. An attitude control device configured to control the supply of hydraulic oil to a cylinder to maintain a ground work device in a horizontal attitude,
A regulator valve is provided in the oil supply circuit for the attitude control hydraulic cylinder, and includes a first position where the amount of oil supplied toward the attitude control hydraulic cylinder is small and a second position where the amount of oil supplied is increased. At the same time, a detection means for detecting the operation of the attitude control hydraulic cylinder and a displacement means for displacing the regulator valve whose operation is controlled by the detection means are provided. Only when the regulator valve is activated is the second
An attitude control device for a ground work device configured to displace the device to a position.