JPH02255005A - Control device of working machine of mower or the like - Google Patents

Abstract

PURPOSE:To simplify assembly operation by equipping one side of a block member with a tank and the other side with a motor, integrating a gear pump, etc., into the block member and directly attaching a cylinder to the block. CONSTITUTION:One side of a block member 9 is equipped with a tank T, the other side with a motor M, the block member 9 is provided with a gear pump P, an operation checking valve, a slow return valve, a change valve V, etc., and a cylinder C is directly attached to the block member. An assembly man- hour is reduced and a working machine can be miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device suitable for adjusting the position of a blade of a lawn mower.

(Prior Art) In the conventional device shown in FIG. 7.8, a working machine a is connected to a vehicle body 1 via a rotating shaft 2.

The vertical position of this working machine a is the single-acting cylinder C.
I'm trying to operate and control it.

When the cylinder C configured as described above is extended, the work implement a rotates clockwise in FIG. 7 about the rotating shaft 2, and the blade portion 3 thereof is raised.

Note that reference numeral 4 in the figure is a rod for adjusting the vertical position of the guide roller 5.

Further, the control circuit is as shown in FIG.

That is, a manual switching valve V is connected between a pump P linked to the engine E and the cylinder C, and a slow return valve Sv is connected downstream of the switching valve (2). Each of these constituent elements is separated and independent, and these constituent elements are connected with a hose.

Another conventional example shown in Fig. 9.10 uses a double-acting cylinder C to adjust the position of a working machine. An L-shaped link 6 is rotatably provided at the tip of the rod of this double-acting cylinder C, and this link 6
A chain 7 is connected to the free end (1) of the chain. The tip of this chain 7 is connected to the blade part 3 via a pulley 8.

Therefore, when the cylinder C is extended, the link 6 rotates counterclockwise in the drawing, pulling the chain 7 and causing the blade part 3 to rotate.
lift up. When the cylinder C is contracted from this lifted state, the blade portion 3 together with the link 6 returns to the original position shown in the figure.

The control circuit of this device is as shown in FIG. That is, a pump P linked to an engine E,
A manual switching valve V is connected between the above cylinder C, and a slow return valve S is connected downstream of this switching valve ■.
v is connected. Furthermore, the point that each of these constituent elements is separated and independent and connected by a hose is the same as in the case of Fig. 7.8 above.

(Problems to be Solved by the Invention) In the conventional device as described above, each component connected between the pump P and the cylinder C is separated and independent, and these independent components are connected with a hose. Therefore, there was a problem in that the number of assembly steps increased, making the assembly process inefficient.

An object of the present invention is to provide a device in which waste components such as a pump, a tank, and a switching valve are packaged to simplify assembly work.

(Means for Solving the Problems) This invention includes a block member connected to a tank, and this block member includes a gear pump, a passage communicating with one chamber of the cylinder, and a passage communicating with the other chamber. and an operated check valve provided on the passage side that communicates with the one chamber described above to allow free flow of flow from the gear pump to one chamber of the cylinder, and a slow return valve provided downstream of the operated check valve. On the other hand, the present invention is characterized in that a switching valve that is switched by pressure action on the discharge side of the gear pump and guides the fluid in the tank to the suction side of the gear pump is connected to the block member.

(Operation of the present invention) Since the present invention is configured as described above, a gear pump, an operating check valve, a slow return valve, etc. are incorporated in advance into the block member, and a passage is formed to communicate these elements. Therefore, when assembling the device, the assembly is completed simply by connecting the block member and the switching valve.

(Effects of the Present Invention) According to the device of the present invention, the number of man-hours required for assembly is reduced, so that work efficiency is improved accordingly, and the overall size of the device can be reduced.

(Embodiment of the present invention) In the first embodiment shown in FIGS. 1 to 5, one end of the tank T is blocked by a block member 9, and this block member 9 is equipped with a gear pump P, an operating check valve OT, and a slow return valve. It incorporates Sv.

There are inflow and outflow ports 10 on both sides of the gear pump P.
．． 11 and both these ports 10.11
As shown in FIG. 4, each of them is communicated with the relay chamber 12 and pilot chamber 13 of the operated check valve OT.

The above-mentioned operated check valve OT partitions the above-mentioned relay chamber 12 and pilot chamber 13 on both sides of the bushing member 14, and is provided with a poppet 15 on the downstream side of the relay chamber 12. This poppet 15 normally closes the seat portion 17 under the action of a spring 16. When pressure fluid flows into the relay chamber 12 from the port 10 in this state, the poppet 15 opens against the spring 16, allowing the pressure fluid to flow toward the passage 18.

On the other hand, when the poppet 15 is closed as shown,
Flow from passage 18 to relay chamber 12 is blocked. However, when pilot pressure acts on the pilot chamber 13, the bushing member 14 moves due to the pressure action, and the poppet 15 is forcibly opened. When the poppet 15 is forcibly opened in this way, the flow from the passage 18 to the relay chamber 12 is allowed.

A slow return valve Sv is provided on the downstream side of the passage 18, and this slow return valve is mainly composed of a cylindrical valve member 19 with one end closed. This valve member 19 is inserted into a recess formed in the block member 9, and the inner diameter of this recess is made larger than the outer diameter of the valve member 19, so that a passage is formed outside the valve member 19.
0 is formed.

The valve member 19 configured as described above has its closing surface 21 located on the passage 18 side, and has an orifice 22 formed in the closing surface 21. Furthermore, the slow return valve is connected to the bottom chamber 23 of the cylinder C on the downstream side.

Now, when pressurized fluid is applied from the passage 18 side, the valve member 19 moves downward from the position shown in FIG. 4 due to the pressure action, opening the passage 20 and creating a free flow state. On the other hand, when fluid flows from the bottom chamber 23 of the cylinder C, the pressure action at that time causes the valve member 19 to enter the state shown in FIG. 4 and close the passage 20. When the passage 20 is closed in this manner, the bottom chamber 23 communicates with the passage 18 only through the orifice 22, so the amount of flow from the bottom chamber 23 is restricted.

Note that the rod side chamber 24 of the cylinder C is connected to the passage 25.
It is connected to tank T via 26.

A valve case 27 of a switching valve V is connected to the block member 9 constructed as described above. A spool 28 is slidably housed inside the valve case 27, and both sides of the spool 28 can be closed with plugs 29, 30.

A pilot chamber 31.32 is formed between the spool 28 and the plug 29.30, and the pilot chamber 31.32 is communicated with the inflow/outflow port 10.11 through a communication hole 33.34. There is.

The spool 28 constructed as described above has a spring 35.3.
6, the neutral position shown in the figure is normally maintained. Spool 2
8 in the neutral position shown, both ports 10.1
1 and the tank T is cut off. From this state, when pilot pressure acts on one pilot chamber 31, the spool 28 moves against the spring 36. When the spool 28 moves in this way, the inflow/outflow port 11
However, it communicates with the tank T via the communication hole 34 → the pilot chamber 32 → the recess 37 on one side of the spool → the notch 38 formed in the spool → the filter 39. Furthermore, when pilot pressure acts on the other pilot chamber 32, the spool moves downward. Therefore, the inflow and outflow port 10
However, it communicates with the tank T via the communication hole 33 → the pilot chamber 31 → the other recess 40 of the spool → the above-mentioned notch 38 → the filter 39.

One of the plugs 29 is provided with a relief valve 41, and the other plug 30 is provided with an orifice 42.

In addition, the reference numeral 43 in the figure is a stop valve for communicating the passage 18 with the passage 26.

When the morph m is rotated and the gear pump P is rotated in the forward direction, the inflow and outflow ports 10 become high pressure, but the pressure at this time acts on the pilot chamber 31, and the spool 2 of the switching valve V
Move 8 upward. When the spool 28 moves in this way, the fluid from the tank T flows into the other outflow/inflow port 11 side, so the pump P discharges the fluid sucked in from the outflow/inflow port 11 from the outflow/inflow port 10. Then, due to this pressure fluid, the operating check valve OT
is pushed open and the valve member 19 of the slow return valve Sv is pushed down, so the supply side passage maintains a free flow state.

Therefore, the discharged fluid is supplied to the bottom side chamber 23 of the cylinder C, and extends the cylinder C to raise the blade portion 3 of the working machine a.

Furthermore, when the gear pump P is reversed, its discharge fluid flows into the pilot chamber 32, but the fluid that flows into the parrot chamber 32 flows out into the tank T via the orifice 42. As the fluid passes through the orifice 42 in this manner, the pressure on the upstream side within the orifice 42 increases, and the spool 28 of the switching valve (2) moves downward due to the action of this pressure.

Therefore, the pump P discharges the fluid sucked in from the outflow/inflow boat 10 from the outflow/inflow boat 11. The pressure fluid discharged from the inflow/outflow boat 11 in this manner acts on the pilot chamber 13 of the operated check valve OT, pushes the bushing member 14, and forces the poppet 15 open.

When the operating check valve opens, the fluid in the bottom chamber 23 of the cylinder C flows out, and the valve member 19 of the slow return valve Sv is pressed upward by the fluid pressure at this time. For this purpose, the passage 20 is closed, so that the return fluid returns to the tank T via the orifice 22. That is, the return speed of the cylinder C at this time is controlled by the orifice 22 and becomes slow.

Incidentally, when the guide roller 5 rides on a convex portion of the cutting surface while the working machine a is traveling, the cylinder C is extended. Therefore, at this time, the fluid in the rod side chamber 24 is returned to the tank T via the passages 25, 26. Although the cylinder C is returned to the tank T in this way, the expansion speed of the cylinder C is attenuated by the passage resistance during the return process. Therefore, the cylinder C does not jump up suddenly when climbing over a convex portion of the cutting surface. However, it is of course possible to actively provide an orifice in any of the passages 25, 26 in order to dampen the rate of expansion of the cylinder C.

In addition, in this case, if the spring force of the spring 16 is set so that the operating check valve OT does not open, the inside of the bottom side chamber 23 becomes negative pressure when the cylinder C is extended, so this negative pressure By this action, the cylinder C can be automatically returned to its original position.

Note that it goes without saying that a relief valve may be used in place of the orifice 42.

In the second embodiment shown in FIG. 6, the other inflow/outflow boat 11 of the gear pump P is communicated with the tank via a passage 26, and an orifice 42 is provided in the communication process. Note that in this embodiment, the orifice 4
2 may be replaced with a sequence valve.

[Brief explanation of drawings]

Drawings 1 to 5 show a first embodiment of this invention.
Fig. 1 is a circuit diagram, Fig. 2 is a vertical sectional view, Fig. 3 is a partially enlarged sectional view of the main part, Fig. 4 is a sectional view taken along the rV-IVV line in Fig. 3, and Fig. 5 is a V in Fig. 3. 6 is a circuit diagram of the second embodiment, and FIG. 7.8 is a conventional device.
The figure is a side view showing the vehicle main body and the working machine, Fig. 8 is a circuit diagram, Fig. 9.10 shows another conventional example, and Fig. 9 shows the vehicle main body and the working machine. The side view and FIG. 10 are circuit diagrams. C-...Cylinder, S V...Slow return valve, 9...Block member, P...Gear pump, OT
-...Operate check valve, 18.25.26...
Passage, T...Tank, ■...Switching valve.

Claims (1)

[Claims] A block member is connected to the tank, and the block member has a gear pump, a passage communicating with one chamber of the cylinder, a passage communicating with the other chamber, and a passage communicating with the one chamber, It incorporates an operated check valve that allows free flow of flow from the gear pump to one chamber of the cylinder, and a slow return valve provided on the downstream side of this operated check valve, and is switched by pressure action on the discharge side of the gear pump, A control device for a working machine such as a lawn mower, in which a switching valve for guiding fluid in a tank to the suction side of a gear pump is connected to the block member.