JPH10339263A - Changeover control device for highly viscous fluid pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize a stopping and returning position of a hydraulic piston and elongate the life of the piston so as to form a grease port on a retreating side stroke end of a fluid feeding cylinder. SOLUTION: A computation device 26 is assembled in a changeover control device of a highly viscous fluid pump so as to stabilize a returning position of a hydraulic piston of a main hydraulic cylinder. The computation device 26 has a measuring part 27 which measures a time gap T1 in the case that hydraulic pistons of two main hydraulic cylinders alternatively reach stroke ends based on signals from sensors LS1, LS2, and a setting part 28 which set a delay time T2 for retarding changeover command to an electromagnetic changeover valve based on the measured time T1 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention controls a high-viscosity fluid pump for sucking and discharging a high-viscosity fluid such as concrete so that the main hydraulic cylinder is switched in accordance with the speed of a hydraulic piston of the main hydraulic cylinder. The present invention relates to a switching control device for a high-viscosity fluid pump.

[0002]

2. Description of the Related Art In a double-row hydraulic cylinder type high-viscosity fluid pump, when one of the two main hydraulic cylinders moves forward and reaches a stroke end, a sensor operates to operate a suction / discharge valve (oscillating valve). , Sliding valves, etc.) and switching the hydraulic piston of the main hydraulic cylinder in the opposite direction.

[0003] As an example, when a swing valve type is adopted as a suction / discharge valve, as shown in Figs. 4 and 5,
Two suction and discharge ports 2 are provided side by side at the lower part of the front surface of the hopper 1, and two fluid pressure feeding cylinders 3 and 4 communicating with the two suction and discharge ports 2 are installed in parallel outside the hopper 1. Then, the fluid-pressure-feeding piston 5 housed in each of the fluid-pressure-feed cylinders 3, 4 is connected to the fluid-pressure-feed cylinder 3, 4.
The hydraulic pistons 9 in the main hydraulic cylinders 7 and 8 connected to the main hydraulic cylinders 7 and 8 via the washing chamber 6 are integrally connected via one rod 10 respectively, and the hydraulic pistons 9 of the main hydraulic cylinders 7 and 8 are alternately advanced. By retreating, the fluid pressure feeding pistons 5 are alternately advanced and retreated. Further, an oscillating pipe 11 bent in an S-shape is located in the hopper 1, and a seal ring 12 is attached to one end of the oscillating pipe 11 so that the two can alternately coincide with the two suction / discharge ports 2. At the same time, the other end of the oscillating tube 11 penetrates the back surface of the hopper 1 to be connected to the transport tube 13, and a connecting shaft 14 fixed in the middle of the oscillating tube 11 is installed outside the hopper 1. The two swing cylinders 16 and 17 are connected via an operation lever 15 and the operation lever 15 is tilted left and right so that the swing tube 11 can be swung in the left and right direction about the connection shaft 14. is there.

When the high-viscosity fluid 18 in the hopper 1 is sucked and discharged by the above-mentioned high-viscosity fluid pump, the oscillating pipe 11 is oscillated and the suction and discharge corresponding to the fluid pressure feeding cylinder 3 which has already been sucked is performed. When located at the outlet 2, the hydraulic pumping piston 5 of the hydraulic pumping cylinder 3 is advanced by the main hydraulic cylinder 7, and the highly viscous fluid 18 sucked into the hydraulic pumping cylinder 3 is discharged through the oscillating pipe 11. At the same time, another fluid pressure feeding cylinder 4 retracts the fluid pressure feeding piston 5 so that the highly viscous fluid 18 in the hopper 1 is sucked through the suction / discharge port 2. Is swung to another suction / discharge port 2 side to cause the fluid pressure feeding cylinders 3 and 4 to operate in the reverse of the above-described manner.
8 is continuously discharged into the transport pipe 13 through the swing pipe 11.

As described above, an example of a switching control circuit of a high-viscosity fluid pump for performing suction and discharge of the high-viscosity fluid 18 is shown in FIG. Pressure oil supply / discharge line 19 for supplying / discharging pressure oil to / from the side pressure chamber
In the middle of the above, an electromagnetic switching valve 20 is provided, and the rod-side pressure chambers of the main hydraulic cylinders 7 and 8 are connected to each other by a sealed circuit 22,
The hydraulic oil discharged from the oil pump 21 is alternately supplied to the main hydraulic cylinders 7 or 8 by switching the electromagnetic switching valve 20, and the hydraulic pistons 9 of the main hydraulic cylinders 7 and 8 are alternately moved forward and backward to change the fluid. A line for alternately switching the pressure-feeding cylinders 3 and 4 between the suction side and the discharge side so as to discharge a high-viscosity fluid into the transport pipe 13, and supplying and discharging pressure oil to and from the two swing cylinders 16 and 17. An electromagnetic switching valve 24 is provided in the middle of 23, and by switching the electromagnetic switching valve 24, the swing cylinders 16 and 17 are alternately moved forward and backward to swing the swing tube 11 right and left. To 2
Reference numeral 5 denotes an oil tank.

At the stroke end of each of the main hydraulic cylinders 7 and 8 on the forward side, sensors LS1 and LS2 are provided.
When the main hydraulic cylinder 7 or 8 reaches the stroke end and the sensor LS1 or LS2 operates, the solenoid SOL. 1 or SOL. 2 is energized so that the electromagnetic switching valve 20 is switched to the port a or b, and the solenoid S of the electromagnetic switching valve 24 is
OL. 3 or SOL. 4 is excited and the electromagnetic switching valve 2
4 is switched to port a or b.

In the above-mentioned high-viscosity fluid pump, in order to lubricate each of the fluid-pressure-feeding pistons 5 of the fluid-pressure-feed cylinders 3, 4, the position of the retreat-side stroke end of each fluid-pressure feed cylinder 3, 4 (FIG. 4). It is necessary to inject grease in section A), but the hydraulic piston 9 of the main hydraulic cylinders 7 and 8 changes the overrun distance at the stroke end position depending on the operating speed.
At the time point when the hydraulic piston 9 of the main hydraulic cylinder 7 is detected by the sensor LS1 at the forward stroke end, the hydraulic piston 9 of the main hydraulic cylinder 8 has not reached the backward stroke end, and the hydraulic pressure feeding cylinder 4 is moved backward. The end may not be reached, and the stop turning position may not be constant.

For this reason, conventionally, a grease port for lubricating the fluid-pressure feeding piston 5 cannot be provided at the retreat-side stroke end of the fluid-pressure feeding cylinders 3 and 4, and the main hydraulic cylinders 7 and 8 and the fluid-pressure feeding are not provided. Cylinders 3, 4
In this case, oil for lubrication is put in the washing chamber 6 located between the two.

[0009]

However, if the cleaning chamber 6 is configured to contain oil for lubrication, the cleaning chamber 6 containing oil for lubricating the piston 5 for fluid pressure feed contains a highly viscous fluid 18 in the cleaning chamber 6. May enter from inside the fluid pressure feeding cylinders 3 and 4 and mix with the lubricating oil, and further into the sealing circuit from the gland portions of the main hydraulic cylinders 7 and 8, which may damage the hydraulic piston 9 and the oil tank 25. There is a problem that the pressurized oil inside is contaminated.

There is also a system in which the operation timing of the main hydraulic cylinder and the cylinder for switching the suction / discharge valve is controlled by a timer which is inversely proportional to the engine speed (Japanese Patent No. 2525).
No. 75688) is a pump that handles a high (strong) viscous fluid such as concrete, because the discharge rate control is performed by changing not only the engine speed but also the discharge rate of the oil pump from zero to the maximum. In addition, it is extremely difficult to control the position where the piston is turned back over the entire range of use.

In view of the above, the present invention has been made to stabilize the turning-back position of the hydraulic piston of the main hydraulic cylinder, and to provide a grease port at the backward stroke end of the hydraulic pressure feeding cylinder to lubricate the hydraulic pressure feeding piston. It is an object of the present invention to provide a switching control device for a high-viscosity fluid pump that can extend the life of a piston.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is designed to alternately supply pressure oil from an oil pump to two main hydraulic cylinders via an electromagnetic switching valve. The pressure oil from the oil pump is alternately switched between the suction and discharge valves via another electromagnetic switching valve, and the suction and discharge is performed based on the operation of a sensor provided at the forward stroke end of the two main hydraulic cylinders. In a switching control device for a high-viscosity fluid pump configured to switch between an electromagnetic switching valve for a valve and an electromagnetic switching valve for the main hydraulic cylinder, the hydraulic pistons of the two main hydraulic cylinders alternately move forward. A measuring unit that measures the interval to reach the end by a signal from the sensor, and outputs a switching command to the electromagnetic switching valve for the main hydraulic cylinder according to the measuring time obtained by the measuring unit. And integrate into an become an arithmetic unit and a setting unit for setting a delay time in.

With the signals from the sensors at the stroke end of each forward side of the two main hydraulic cylinders as inputs, the interval is measured by the measuring unit of the arithmetic unit.
The delay time of the output command to the electromagnetic switching valve is controlled according to the measurement time. As a result, the stop turning position can be kept constant over a wide range from a high speed to a low speed of the hydraulic piston.

The delay time in the setting section can be set stepwise or steplessly.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. As shown in FIG. 6, the pressure oil from an oil pump 21 is switched by an electromagnetic switching valve 20 so that two main hydraulic cylinders 7, 8 and alternately supply the pressure to the head side pressure chambers and alternately move the swinging cylinders 16 and 17 forward and backward by switching the electromagnetic switching valve 24. 8 is operated when the sensor LS1 or LS2 provided at the end of the forward stroke of the solenoid SOL. 3 or S
OL. 4 is excited so that the electromagnetic switching valve 24 is switched, and the solenoid SOL. 1 or SOL. In the switching control device of the high-viscosity fluid pump in which the electromagnetic switching valve 20 is switched by being energized, an arithmetic unit 26 for stabilizing the stop turning position of the hydraulic piston 9 of the main hydraulic cylinders 7, 8 Is incorporated.

[0017] The computing device 26, for the hydraulic piston 9 of the two main hydraulic cylinders 7 and 8 to measure the time interval T ₁ reaches the forward side stroke end alternately based on a signal from the sensor LS1, LS2 The measuring unit 27 and the solenoid SOL. Of the electromagnetic switching valve 20 according to the time T ₁ measured by the measuring unit 27. 1 or SOL. Command to excite 2 and
The solenoid SOL. 3 or SOL.
The delay time T ₂ of the up and outputs a command to excite the 4 and a setting unit 28 for setting.

[0018] In the setting unit 28, as shown in FIG. 2 (b), or to control the delay time T ₂ stepwise by separating the measuring time T ₁ in stages, or 2 (b as shown in), the delay time T ₂ corresponding to the magnitude of the measurement time T ₂ are so as to control continuously.

FIG. 3 shows the main hydraulic cylinder 7 and the sensor L
This shows the relationship with S1, and the rod-side end block 2
A rod 10 having a hydraulic piston 9 slidably housed in a cylinder body 31 whose both ends are closed by a head end block 30 and a hydraulic piston 9 and a base end of which is attached to the hydraulic piston 9
The rod end block 29 is slidably penetrated through the rod end block 29 so as to protrude outside the cylinder body 31. An annular concave portion 33 having the same diameter as the inner diameter of the cylinder body 31 so as to communicate with the inside of the cylinder body 31 so as to extend the rod-side pressure chamber partitioned by the hydraulic piston 9 at the end position on the side of the cylinder.
And the rod-side end block 2
9, a hole 34 communicating with the concave portion 33 in the radial direction is formed, and a sensor LS1 using a Hall element is installed in the hole 34 so as to face the inside of the concave portion 33. A ring-shaped sensor 32 is attached to the rod-side pressure receiving surface of the piston 9. When the hydraulic piston 9 reaches the stroke end on the forward side, the sensor 32 enters the recess 33 and is detected by the sensor LS <b> 1. Thus, the forward stroke end position of the hydraulic piston 9 is detected. Reference numeral 35 denotes a ground portion. The main hydraulic cylinder 8 has the same configuration.

Next, the operation will be described with reference to FIGS.

When the hydraulic pistons 9 of the main hydraulic cylinders 7 and 8 are alternately moved forward and backward, when the stroke end reaches the forward stroke end alternately, the position is detected by the sensor LS.
1 and LS2 are sequentially detected. At this time, signals from the sensors LS1 and LS2 are
And the signal from the sensor LS1 and LS
Interval between the signal from the 2 is measured as the time T _1.

Subsequently, the setting unit 28 sets the measurement time T
Delay time T ₂ corresponding to ₁ is set based on the mode shown in FIG. 2 (a) or (b), after the delay time T ₂ elapses, the solenoid SOL of the solenoid selector valve 24. 3 or SO
L. 4 is output. Thereby, the electromagnetic switching valve 24 is switched, and the swing cylinders 16 and 1 are switched.
7 is operated in the reverse direction, and the solenoid SOL. 1 or SOL. When the solenoid 2 is excited, the electromagnetic switching valve 20 is switched.

In the above description, the solenoid-operated directional control valve 20 sets the interval measurement time T ₁ based on the signals from the sensors LS1 and LS2.
Order to be switched after the elapse of the delay time T ₂ that is set based on, but so that the switching is delayed, this places the hydraulic piston 9 of the main hydraulic cylinder 7,8 is folded reaches near the stroke end position Done. That is, regardless of whether the speed of the hydraulic piston 9 is high or low, the stop / turn position of the hydraulic piston 9 can be kept constant.

For this reason, a grease port for lubricating the hydraulic pumping piston is provided at the position of the retreat stroke end of the hydraulic pumping cylinders 3 and 4 so that the hydraulic pumping piston 5 is provided.
The lubricating oil can be reliably supplied to the washing chamber 6, so that there is no need to put lubricating oil into the cleaning chamber 6. The life of the hydraulic piston 9 can be extended.

In the above-described embodiment, the case where the switching command to the electromagnetic switching valves 20 and 24 is output at the same time has been described. What you may do,
Of course, various changes can be made without departing from the spirit of the present invention.

[0026]

As described above, according to the present invention, the hydraulic oil from the oil pump is alternately supplied to the two main hydraulic cylinders via the electromagnetic switching valve, and the oil from the oil pump is supplied from the oil pump. The pressure oil is alternately switched between the suction and discharge valves via another electromagnetic switching valve, and based on the operation of a sensor provided at the forward stroke end of the two main hydraulic cylinders, the electromagnetic system for the suction and discharge valves is operated. In a switching control device for a high-viscosity fluid pump in which a suction valve is switched by switching a switching valve and an electromagnetic switching valve for the main hydraulic cylinder is switched, hydraulic pistons of the two main hydraulic cylinders are alternated. A measuring unit for measuring an interval to reach the forward stroke end by a signal from the sensor, and switching to an electromagnetic switching valve of the main hydraulic cylinder according to a measuring time obtained by the measuring unit. The arithmetic unit having a setting unit for setting a delay time until a command is output is incorporated. Therefore, a signal from a sensor at a forward stroke end of the two main hydraulic cylinders is input, and a measuring unit is used. The interval can be measured at, and according to the measurement time, the delay time of the output command to the electromagnetic switching valve can be controlled by the setting unit.
The stop position of the hydraulic piston can be kept constant over a wide range from high speed to low speed. Therefore, a grease port can be provided at the backward stroke end of the hydraulic pump cylinder to lubricate the hydraulic pump piston. As a result, there is no need to put lubricating oil into the cleaning chamber, and lubricating oil mixed with high-viscosity fluid does not enter the main hydraulic cylinder, thus extending the life of the hydraulic piston. It has the effect.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an arithmetic unit according to an embodiment of the present invention.

FIGS. 2A and 2B show a setting unit of the arithmetic device, wherein FIG. 2A shows a setting mode when delay time is controlled stepwise, and FIG. 2B shows a setting mode when delay time is controlled steplessly. FIG.

FIG. 3 is a cross-sectional view of a main hydraulic cylinder showing an example of a related configuration between a hydraulic piston and a sensor.

FIG. 4 is a partially cut-away side view showing an example of a high-viscosity fluid pump.

FIG. 5 is a diagram showing a portion of the high-viscosity fluid pump of FIG. 4 that swings a swing tube.

FIG. 6 is a diagram illustrating an example of a hydraulic control circuit of a conventional high-viscosity fluid pump.

[Explanation of symbols]

 7, 8 Main hydraulic cylinder 9 Hydraulic piston 20 Solenoid switching valve 21 Oil pump 24 Solenoid switching valve 26 Arithmetic unit 27 Measurement unit 28 Setting unit LS1, LS2 Sensor

Claims (2)

[Claims] 1. A pressure oil from an oil pump is alternately supplied to two main hydraulic cylinders via an electromagnetic switching valve, and a pressure oil from the oil pump is supplied via another electromagnetic switching valve. The intake and discharge valves are alternately switched by switching the electromagnetic switching valve for the intake and discharge valves based on the operation of a sensor provided at the forward stroke end of the two main hydraulic cylinders to switch the intake and discharge valves. Further, in the switching control device for a high-viscosity fluid pump configured to switch the electromagnetic switching valve for the main hydraulic cylinder, the interval at which the hydraulic pistons of the two main hydraulic cylinders alternately reach the forward stroke end is set to the above. A measuring unit for measuring by a signal from the sensor, and a delay for outputting a switching command to the electromagnetic switching valve for the main hydraulic cylinder according to the measuring time obtained by the measuring unit. A switching control device for a high-viscosity fluid pump, comprising an arithmetic unit having a setting unit for setting time. 2. The switching control device for a high-viscosity fluid pump according to claim 1, wherein the measurement unit of the arithmetic unit has a function of setting the delay time stepwise or steplessly.