JPS5945533B2 - Hydraulic drive control device for powder transport vehicles - Google Patents

Description

[Detailed Description of the Invention] A tank for storing powder and granular material, such as powder feed, is mounted on the vehicle frame, and a bottom screw, a vertical screw,
2. Description of the Related Art Powder transport vehicles are known that are equipped with a transport means composed of a discharge screw.

In this conveying means, while the hydraulic motors that drive each screw are sequentially rotated in the normal direction to transport the powder and granules, the conveyance path may sometimes become clogged due to excessive or insufficient transfer of the powder or granules between the screws. This may occur, and if operation is continued in this condition, there is a risk of failure or damage.

Since it is inefficient to stop the drive and perform corrective work by inputting input, it is desirable to perform automatic correction by selectively stopping the screw.

In most cases, clogging of powder and granular material occurs at the transfer section from the bottom screw to the vertical screw, so in this case, it is possible to automatically stop the bottom screw and interrupt the feed toward the vertical screw. It becomes necessary.

Conventionally, some models have installed an internal pilot relief valve on the pressure oil inflow side in order to perform the above operation by utilizing the increase in load on the bottom screw motor caused by the clogging phenomenon. Since the load pressure of the bottom screw motor is basically smaller than the set pressure, the inflow side oil pressure does not rise sufficiently and the relief valve does not operate.

The present invention has found that clogging of powder and granular material occurs after the load pressure of the vertical screw hydraulic motor increases, and based on this knowledge, it has solved the above-mentioned drive control problem. The relief valve for bypassing the pressure oil to the bottom screw hydraulic motor is operated by an external pilot, and this external pilot is led from the inlet of the vertical screw hydraulic motor.

The present invention will be explained in detail below based on embodiments shown in the accompanying drawings.

FIG. 1 shows an example of a powder transport vehicle 1 equipped with the drive control device of the present invention, and a powder storage tank 3 is mounted on the vehicle frame 2.
will be installed.

The inside of this tank is divided, and the upper part of each compartment is provided with a powder loading port 4, and the lower part of the narrowed hem is provided with a delivery port that can be opened and closed. a bottom screw 5, a vertical screw 6 that is conveyed upward from its delivery end, and a discharge screw 1 that is conveyed toward a boom-shaped half-end outlet extending from its upper end.
A conveying means is provided.

The outer cylinder of the vertical screw 6 can be rotated by a bundle 8, and the discharge screw 1 can be raised or lowered by a hydraulic cylinder 9.

Each screw 5, 6. Hydraulic motors B and V serve as driving means for γ, respectively.

D is connected.

These hydraulic motors can be switched between normal rotation and reverse rotation by reversing the direction of flow of pressure oil.

FIG. 2 shows a hydraulic circuit including a drive control device of the present invention for the hydraulic motors B, V, and D.

An oil pump 10 serving as a pressure oil source is driven by the engine of the transport vehicle 1, sucks oil from an oil reservoir 11 through a strainer 12, and sends the pressure oil to a switching valve 14 through a main pipe 13.

An oil return pipe 15 is led from the switching valve 14 to the oil reservoir 11, and an internal pilot type relief valve 16 is provided between the pressure oil main pipe 13 and the oil return pipe 15.

The switching valve 14 can be switched to three positions: a left position for forward rotation, a medium position for stopping, and a right position for reverse rotation, and the left position is shown in FIG.

In this state, pressure oil flows from the sub pipe 1γ branched from the main pipe 13 through the switching valve 14 to the pressure oil pipe 18, first flows into the discharge screw hydraulic motor D, and then flows into the transfer pipe 19.
The oil flows into the vertical screw hydraulic motor V through the transfer pipe 20, and then flows into the bottom screw hydraulic motor B through the transfer pipe 20. The oil that flows out returns to the oil reservoir 11 through the oil return pipe 21, the switching valve 14, and the oil return pipe 15. .

In this way, the hydraulic motors D, V, and B are activated in that order and rotate normally to smoothly transfer and transport the powder and granules.

At the center position, the switching valve 14 becomes an open center, and the pressure oil auxiliary pipe 1γ directly connects to the oil return pipe 15, so that the three motors D, V, and B, which increase the discharge pressure of the oil sent from the oil pump 10, also stop.

In the right position for reversal, pressure oil flows from the main pipe 13 through the switching valve 14 to the conduit 22.

This conduit 22 is led to a transfer pipe 20 that connects the outflow side of the vertical motor and the inflow side of the bottom motor.

This pressure oil flows backward through the vertical screw hydraulic motor V, then flows backward through the discharge screw hydraulic motor D, and returns to the oil reservoir 11 via the pressure oil pipe 18, the switching valve 14, and the oil return pipe 15.

In this way, the hydraulic motors V and D rotate in reverse, and the powder in these screws is discharged from the bottom end of the vertical screw V.

In this case, the oil return pipe 21 of the hydraulic motor B is shut off by the switching valve 14, so that the hydraulic motor B stops without passing oil.

The pressure oil flow side of the bottom screw hydraulic motor B 1 In other words, in this example, from the transfer pipe 20 or conduit 22 to the external pilot type IJ
4 is led to the oil reservoir 11, and an external pilot path 25 for operating the relief valve 23 is led from the inlet of the vertical screw hydraulic motor V, that is, from the transfer pipe 19.

By the way, if the switching valve 14 is operated to the left position for forward rotation and a clogging phenomenon occurs during the process of transporting powder and granules to the outside, the load on the vertical screw hydraulic motor V increases, and as a result, the IJ IJ- This increased load pressure is introduced to the valve 23 through the pilot path, and the valve 23 is opened.

Therefore, the pressure oil for the bottom screw hydraulic motor B is returned to the oil reservoir T, and the supply of powder by the bottom screw 5 is stopped.

On the other hand, since the vertical screw 6 and the discharge screw γ continue to be driven by the hydraulic motors V and D in the normal rotation, they continue to discharge the powder and granular material, thereby resolving the clogging phenomenon.

When the clogging phenomenon is resolved, the pressure acting on the inlet of the vertical screw hydraulic motor V decreases, and the relief valve 23 returns to the closed position, causing the bottom screw hydraulic motor B to resume forward rotation. Then, the supply of powder and granular material by the bottom screw 5 is performed again.

As described above, in the present invention, the relief valve for bypassing the pressure oil to the bottom screw hydraulic motor is configured to be operated by an external pilot, and this external pilot is guided from the inlet of the vertical screw hydraulic motor. So,
Even if a clogging phenomenon occurs when discharging powder or granular material, it is possible to automatically and reliably and quickly eliminate the clogging phenomenon.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view of a powder transport vehicle, and FIG. 2 is a hydraulic circuit diagram including a drive control device according to an embodiment of the present invention. 1...Powder transport vehicle, 2...Car frame, 3
... Powder storage tank, 4 ... Powder charging inlet, 5 ... Bottom screw, 6 ...
・Vertical screw, 1...Discharge screw, 8...Bundle, 9...Hydraulic cylinder, B...Hydraulic motor for bottom screw, ■... ...Hydraulic motor for vertical screw,
D...Hydraulic motor for discharge screw,
10... Oil pump, 11... Oil reservoir, 12... Strainer, 13...
・Pressure oil main pipe, 14...Switching valve, 15...
・Oil retention pipe, 16...IJ IJ-fu valve, 11.
... Pressure oil sub pipe, 18 ... Pressure oil pipe, 19,
20... Transfer pipe, 21... Oil retention pipe, 2
2... Conduit, 23... External pilot type relief valve, 24... Oil retention pipe, 25...
...External pilot conduit.

Claims (1)

[Claims] 1. A powder storage tank mounted on the vehicle frame, and a bottom screw for transporting the powder and granule in the storage tank to the outside.
In a granular material transport vehicle comprising a conveying means constituted by a vertical screw and a discharge screw, and a driving means constituted by hydraulic motors for driving the conveying means, when the granular material is discharged by the conveying means, The hydraulic motors are connected in series to drive the hydraulic motor for the discharge screw, the hydraulic motor for the vertical screw, and the hydraulic motor for the bottom screw in the order of forward rotation. A hydraulic control device for a powder transport vehicle, characterized in that a conduit provided with a valve is branched, and an external pilot for operating the relief valve is guided from an inlet of a hydraulic motor for a vertical screw.