JPS6313980Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic cylinder device for automatic direction control applied to an automatic direction control device of a traveling device used in a mobile agricultural machine such as a combine harvester.

Generally, a combine harvester has a crawler that is wound between a drive sprocket and an idler wheel that are rotatably supported on a running frame.
The drive sprocket is driven via a transmission in a transmission case that is attached via a bracket to a body frame suspended from a running frame. An electromagnetic switching valve and two hydraulic cylinder devices are provided outside the transmission case, and the electromagnetic switching valve is switched by a control signal from a direction sensor provided in the divider section at the front of the aircraft. As a result, the two hydraulic cylinder devices are selectively activated, disconnecting either the left or right side clutch gear that transmits power to the drive sprocket, thereby stopping the rotation of either the left or right crawler. This allows the combine to be automatically oriented instead of manually oriented.

By the way, as mentioned above, in the past, hydraulic cylinder devices were provided separately for the left and right side clutch gears to operate the left and right side clutch gears individually, respectively.
If the electromagnetic switching valve is switched after operating one hydraulic cylinder device and the other hydraulic cylinder device is operated, the circuit residual pressure generated when the hydraulic oil in the one hydraulic cylinder device returns to the tank may The pistons do not return completely, and for a moment it becomes as if the individual pistons of both hydraulic cylinder devices are operating simultaneously, that is, the left and right side clutch gears are disengaged at the same time. It had the disadvantage that it could not be operated in any direction. In order to avoid the above drawbacks, a solution has been adopted in which a strong return spring is provided on the piston of each hydraulic cylinder device to quickly return the piston against the residual pressure in the circuit. In order to operate the piston, the presence of the return spring with the strong spring force described above inevitably requires an increase in the operating pressure, that is, the circuit pressure of the entire hydraulic system, which eliminates the above-mentioned disadvantages, but increases power loss and hydraulic pressure. This method has the drawback of causing new troubles such as oil leakage in the system due to an increase in operating pressure. In addition, since each of the above hydraulic cylinder devices was installed outside the transmission case and operated each side clutch gear indirectly via an appropriate transmission mechanism, there was a delay in operation, and accurate automatic direction control of the combine was caused. It had the disadvantage that it could not be carried out.

Therefore, in this invention, the left side inside the mission case,
The right cylinder members are arranged facing each other, a piston body of a single structure is arranged so that both ends are fitted into the left and right cylinder members, and plate members are fixed at the left and right positions of the intermediate part of the piston body, respectively. When the piston body is actuated, the plate member directly operates the cam bodies that operate the left and right side clutch gears, respectively, and furthermore, the plate member is configured to directly operate the cam bodies that operate the left and right side clutch gears, respectively, and furthermore, the plate member is configured to directly operate the cam bodies that operate the left and right side clutch gears, respectively, and furthermore, the plate member is configured to directly operate the cam bodies that operate the left and right side clutch gears, respectively. In addition, a hydraulic pressure relief part is provided in each of the piston bodies so that the hydraulic pressure escapes into the transmission case when the other end of the piston body comes into contact with the end of the cylinder part. It is an object of the present invention to provide a hydraulic cylinder device for automatic direction control that prevents the circuit oil pressure from rising rapidly when the end is reached.

Hereinafter, in explaining the embodiment of the present invention with reference to FIGS. 5 and 6, the underlying technology will first be explained based on FIGS. 1 to 4.

The mission case 1 has a built-in transmission with gears and the like disposed on each shaft disposed inside the case 1. As shown in FIG. A center gear 3 is supported on the shaft 2. On both sides of the center gear 3, there are left and right side clutch gears 5, 6 each having a structure in which gear parts 5a, 6a and brake parts 5b, 6b are integrally formed.
are fitted so that they can move freely in both the axial and rotational directions, and are normally pressed toward the center gear 3 by springs 7 and 9.
are engaged with internal gear portions 3x and 3y formed at the center of the center gear 3, respectively, to form a clutch, and brake portions 5b and 6b are respectively fixed to the inner wall of the transmission case 1 facing each other. The brake is constructed by slidingly contacting the other brake parts 5x and 5y. Further, a left drive gear 10 and a right drive gear 11 are meshed with the gear portions 5a and 6a of each of the side clutch gears 5 and 6, respectively.
The rotation of the left drive gear 10 drives the left side drive sprocket (not shown) through the left drive shaft 12, and the rotation of the right drive gear 11 drives the right side drive sprocket (not shown) through the right drive shaft 13. There is. And the above left and right side clutch gears 5,
A hydraulic cylinder device 15 for automatic direction control according to the present invention is disposed above 6, and each cylinder device 15 has a left cylinder fitted so as to face the inside of the transmission case 1. Member 16
and a right cylinder member 17, and a piston body 19 of a unitary structure whose both ends are fitted into the cylinder members 16 and 17. Disc-shaped plate members 20a and 20b are fixed to the piston body 19 at the left and right positions of the intermediate portion, respectively, by welding or the like, and the respective plate members 20
A, 20b and the left and right cylinder members 16, 17 are provided with a return compression spring 21a, which has a relatively weak spring force.
21b is interposed, so that the piston body 19 is located at the center of both cylinder members 16, 17 in a normal state. As shown in FIGS. 2 and 3, each of the plate members 20a and 20b is provided with a cam that rotates about shafts 22a and 22b that are pivotally supported by the mission case 1. The bodies 23a and 23b are brought into contact with each other, and furthermore, the pins 25a and 25b fixed to the intermediate portions of the cam bodies 23a and 23b are fitted into the grooves 5c and 6c of the side clutch gears 5 and 6, respectively. When the piston body 19 moves toward one of the cylinder members 16 and 17, the plate members 20a and 20b move toward the cam bodies 23a and 23.
b, thereby connecting the side clutch gears 5 and 6 to the center gear 3 via pins 25a and 25b.
It is designed to move in the direction of leaving the target. Note that the symbols D and E in FIG. 1 are hydraulic pipes connected to the cylinder members 16 and 17, and the symbols 26a and 2 in FIGS.
6b is a side clutch arm, and 27b in FIG. 2 is an operating wire. For example, by manually pulling the operating wire 27b, the cam body 23b can be moved.
By rotating the side clutch gear 6, the side clutch gear 6 can be moved.

Next, based on FIG. 4, the hydraulic cylinder device 15
Explain the hydraulic circuit for operating the. The hydraulic circuit in FIG. 4 includes a pump 3 driven by an engine 30.
1. Manual switching valve 32, single-acting hydraulic cylinder device 3
3, the electromagnetic switching valve 35, the previously explained hydraulic cylinder device 15 according to the present invention, and the relief valve 36,
It has a tank 37 and the like made up of the transmission case 1, and is further made up of hydraulic conduits A to F that connect the above-mentioned circuit elements. The manual switching valve 33 is a 4-port, 3-position switching valve having a switching flow path as shown in the figure, and operates the single-acting hydraulic cylinder device 33 downward in one position, locking in another position, and locking in one position. The above-mentioned operations of the single-acting hydraulic cylinder device 33 cause the pre-processing section of the combine to be lowered, locked, and raised accordingly. The electromagnetic switching valve 35 is a 4-port, 3-position switching valve having a switching flow path as shown in the figure.
By selectively energizing the solenoids x and y, the piston body 19 of the hydraulic cylinder device 15 is actuated rightward in the position, the piston body 19 is returned to the neutral position in the position having an open center type flow path, and in the position The piston body 19 is operated leftward.

Next, an embodiment of the present invention will be described based on FIGS. 5 and 6.

What is shown in FIGS. 5 and 6 is a piston body 1 which is a partially modified version of the above-mentioned hydraulic cylinder device 15, respectively.
9 and the cylinder members 16 and 17, and the hydraulic pressure relief portions provided at both ends of the fitting portion between the cylinder member 1 and the cylinder members 16 and 17 are shown in detail.
The inner diameter of 6, 17 is the inner diameter of the inner portion 16a, 17
The inner diameter _D2 of a is formed to be slightly larger than the inner diameter D1 of the outer portions 16b and 17b so that the inner diameter _D2 of a forms a hydraulic pressure relief part. Holes 19a and 19b are formed on both end surfaces of the piston body 19 so as to constitute a
Further, grooves 1 are formed on the circumferential surface near both ends of the piston body 19.
9c, 19d are carved, and those holes 19a, 1
9b and the grooves 19c, 19d are the grooves 19c, 19.
The piston body 19 is configured to communicate with each other through holes 19e and 19f drilled in the cylinder members 16 and 17 from its neutral position, respectively.
When moved a predetermined distance in the direction of the inner end surfaces 16c, 17c, the pressure oil flowing from the hydraulic pipes D, E is released from the inner end surfaces 16c, 17c.

Since this embodiment has the above configuration, in the hydraulic circuit state shown in FIG.
The pressure oil from 1 flows from pipe A through the neutral position of the switching valve 32 into pipe C, further passes through the neutral position of the electromagnetic switching valve 35, and connects to pipe F along with pipes D and E. It is returned to the tank 37 constituted by the case 1. In this state, the left and right cylinder members 16, 1 of the hydraulic cylinder device 15
As mentioned above, the hydraulic pipes D and E connected to the tank 37 are both connected to the pipe F leading to the tank 37, so both ends of the piston body 19 are at the same pressure, and since no working pressure is applied, the piston The body 19 is kept in a neutral state by return springs 21a, 21b shown in FIG.
3b is not operated at all, so that the gear parts 5a and 6a of the left and right side clutch gears 5 and 6 are both engaged with the internal gear parts 3x and 3y of the center gear 3,
Therefore, the left and right drive gears 10 and 11 are both driven, so that the combine runs straight ahead. In this state, a direction change control signal is sent from the direction sensor to the electromagnetic switching valve 3, for example.
5, the switching valve 35 is switched to the position, and the pipe C becomes the pipe D.
Since the pipe F is connected to the pipe E, the pressure oil from the pump 31 is supplied to the left cylinder member 1 of the cylinder device 15.
6 and pushes the piston body 19 to the right, and the oil in the right cylinder member 17 flows into the piston body 19.
is pushed out and returned to the tank 37.
In this way, when the piston body 19 is moved rightward to the state shown in FIG. 1, the plate member 2
The cam body 23b is rotated by the pin 25b, and the right side clutch gear 5 is moved rightward against the spring 9, and the gear portion 6b is rotated by the pin 25b.
is disengaged from the internal gear portion 3y of the center gear 3, and the brake portion 6b is disengaged from the other brake portion 6y.
The right side clutch gear 5 is in a state where its rotation is stopped, and therefore,
The right drive shaft 13 is in a stopped state. Therefore, the driving force from the center gear 3 is transmitted only to the left crawler via the left drive gear 10, left drive shaft 12, etc., so that the combine harvester is turned rightward. Furthermore, when the control signal from the direction sensor disappears from this state, both the solenoids x and y become de-energized, and the electromagnetic switching valve 35 becomes in the neutral position, but at this time, the hydraulic cylinder device 15 is activated as described first. As shown in FIG. As shown in FIG. 4, the piston body 19 can be returned to its neutral position very quickly without being affected by the residual pressure in the circuit. Ru.

At this time, in the embodiment shown in FIG. 5, for example, the piston body 19 moves from the neutral position toward the cylinder member 17 on the right side in the figure, and one end of the piston body 19 When the left cylinder member 16 comes into contact with the inner end 16c of the left cylinder member 16, the oil pressure escapes from the gap between the inner part 16a and the cylinder part 16 to the inner end 16c, and the oil pressure is transferred to the inside of the mission case 1, that is, the mission case. 1 is directly returned to the tank 37 made up of 1 without passing through an oil path.

Further, in the embodiment shown in FIG. 6, one end of the piston body 19 is connected to the cylinder member 17, as described above.
When it comes into contact with the end of the cylinder part of the left cylinder member 16, the hydraulic pressure of the left cylinder member 16 flows from the groove part 19c to the inner end 16 through the hole 19e formed in the groove part 19c from the hole 19a.
c, and the hydraulic pressure is inside the transmission case 1.
In other words, a tank 3 composed of a mission case 1
7 directly without going through an oil path.

As explained above, according to the present invention, the left and right cylinder members 16 and 17 are provided in the transmission case 1.
are arranged facing each other, and the left and right cylinder members 16, 17
A piston body 19 having a single structure is disposed such that both ends thereof are fitted into the piston body 19, and plate members 20a and 20b are respectively fixed to the left and right positions of the intermediate portion of the piston body 19, thereby controlling the operation of the piston body 19. At this time, the cam bodies 23a and 23b operate the left and right side clutch gears 5 and 6 by the plate members 20a and 20b.
Since the switching valves 35 are configured to operate directly, when the switching valve 35 is switched to communicate from one cylinder member 16 to the other cylinder member 17, the movement of the integrally structured piston body 19 causes the flow to flow from one cylinder member to the other cylinder member. The other cylinder member is forcibly discharged based on the supply of pressure oil, and the piston body 19 is moved extremely quickly even if the circuit residual pressure increases, so automatic direction control of the mobile agricultural machine is achieved without malfunction. Moreover, the spring force of the return springs 21a and 21b for returning the piston body 19 to the neutral position can be relatively weak. Accordingly, the operating pressure of the hydraulic system connections can be reduced, and troubles in the hydraulic system connections can be reduced.Furthermore, the hydraulic cylinder device 15 is installed inside the mission case 1, and the piston body 19 is directly connected to the hydraulic cylinder device 15. Cam body 23a, 2
3b, so there is less delay in operation and higher responsiveness.In addition, the structure can be made compact and simple without leaking hydraulic oil to the outside, and failures due to foreign objects such as dirt and debris are eliminated.
Maintenance is also easier. Further, at both ends of the fitting portion between the piston body 19 and the cylinder members 16 and 17, so that hydraulic pressure escapes into the mission case 1 when the other end of the piston body 19 comes into contact with the end of the cylinder part. Since the hydraulic pressure relief parts 16a and 17a are provided, the circuit hydraulic pressure does not rise suddenly even when the piston body 19 operates and reaches its stroke end, and therefore the relief valve 36 is closed by the operation of the piston body 19. It is not activated frequently,
As a result, the power loss of the pump 31 can be reduced, and automatic direction control using hydraulic pressure becomes possible even in a small combine harvester with a small engine capacity. Then, while the piston body 19 is in contact with the end of the cylinder part, the hydraulic pressure relief parts 16a, 1
The hydraulic pressure flowing from 7a is supplied to the tank 3 configured in the mission case 1, that is, the case 1.
7, there is no need to provide a return oil path for oil pressure return, and therefore the hydraulic circuit can be simplified, making the device more compact and reducing costs. Also,
When the switching valve 35 is an open center type electromagnetic switching valve having a neutral switching position, when the switching valve 35 is set to the neutral switching position, oil is pumped from the activated cylinder member 16 to the actuated cylinder member 17. As a result, the piston body 19 is quickly returned to the neutral position, the number of times the automatic direction control device is operated is increased, and automatic direction control with good performance can be performed.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a partial internal structure of a transmission case in which a hydraulic cylinder for automatic direction control, which is the basic technology of the present invention, is built in, and Fig. 2 is a sectional view taken along the arrow A-A in Fig. 1. , FIG. 3 is a side view showing the relationship between the plate member of the piston body and the cam body as seen from the right side of FIG. 2, FIG. 4 is a hydraulic circuit diagram for operating this hydraulic cylinder device, and FIG. 6 and 6 are partial plan cross-sectional views showing different embodiments of the present invention, respectively. 1...Mission case, 5, 6...Side clutch gear, 12, 13...Drive shaft, 15...Hydraulic cylinder device for automatic direction control, 16, 17...
Cylinder member, 16a, 17a... Hydraulic pressure relief part (inward part), 19... Piston body, 20a, 2
0b...Plate member, 23a, 23b...Cam body, 35...Switching valve.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A hydraulic cylinder device is actuated by controlling the switching valve according to a control signal from a direction sensor, and the left and right side clutch gears in the transmission case are operated separately. In the automatic direction control device for a mobile agricultural machine which selectively transmits the driving force from the prime mover to the left and right drive shafts, left and right cylinder members are disposed facing each other in the transmission case, and the left and right cylinder members are arranged oppositely in the transmission case. A piston body of a single structure is disposed so that both ends are fitted into the right cylinder member, and plate members are fixedly installed at the left and right positions of the intermediate part of the piston body, so that when the piston body is operated, The plate member is configured to directly operate the cam bodies that operate the left and right side clutch gears, and the other end of the piston body is located at both ends of the fitting portion between the piston body and the cylinder member. A hydraulic cylinder device for automatic direction control, characterized in that a hydraulic pressure relief portion is provided in each of the transmission cases so that hydraulic pressure escapes into the transmission case when the cylinder contacts the transmission case. (2) The hydraulic cylinder device for automatic direction control according to claim 1, wherein the switching valve is an open center type electromagnetic switching valve having a neutral switching position.