JPS61279785A - Sequence driving device of concrete pump - Google Patents

Abstract

PURPOSE:To try to reduce the number of occurrence of vibration and noise by using an accumulator only for force-feeding raw concrete of poor blending under high pressure without using said accumulator for force-feeding ordinary raw concrete under low pressure. CONSTITUTION:In the case of sucking and force-feeding, by concrete pumps 34, 44, raw concrete mixed with little moist and much aggregate and hard to be force-fed, it is arranged that the pressure of a pressure switch PS is set to 120kg/cm<2>. And, when discharge pressure of a hydraulic pump 21 is below 120kg/cm<2>, pressure oil discharged from the hydraulic pump 21 is not supplied to main cylinders 32, 42, which become to make a pause, and pressure oil is stored into an accumulator 28. Also, when the discharge pressure of the oil hydraulic pump 21 becomes above 120kg/cm<2>, pressure oil from the main hydraulic pump 21 is supplied to the main cylinder 32 through a high pressure line 22a, and poorly mixed raw concrete is forcibly fed from the concrete pump 44 as soon as it is sucked into the concrete pump 34.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is capable of controlling ready-mixed concrete by driving a concrete pump and a valve cylinder according to the condition of the ready-mixed concrete.
;:1 Reduces the vibration and noise generated when suctioning and pumping
Sequence drive of concrete pump that can reduce '1・j'
Regarding the equipment.
゛) <Prior art> As shown in Fig. 4, a hydraulic pump 1. ．． 1
Accumulator 2 stores the pressure oil from
13 Pressure of muleta 2 is applied to sequence valve 4
When the pressure exceeds the set pressure, the sequence valve 4 is activated and pressure oil from the hydraulic pump l is supplied to one of the main cylinders 6 via the sequence valve 4 and the main cylinder control switching valve 5.
This main cylinder 6 operates to pump fresh concrete from one concrete pump 8, and at the same time sucks the ready-mixed concrete into the other concrete pump 8 via the valve 9, and then
When the valve control switching valve II is switched, the pressure oil in the accumulator 2 is supplied to the valve cylinder 12 at once via the valve control switching valve 11, the valve 9 is switched instantaneously, and the accumulator 2 is switched again. When the pressure reaches the set pressure of the sequence valve 4, the main cylinder 6 operates to suck fresh concrete into one concrete pump 8 through the valve 9, and at the same time pump the fresh concrete from the other concrete pump 8.

<Problems to be Solved by the Invention> However, in the sequence drive device for the concrete pump described above, the accumulator 2 is switched every time the valve 9 is switched.
Since the valve 9 is switched at high speed and high pressure using the switch, there is a problem in that vibration and noise are generated during the switching. Also,
The switching of the valve 9 is performed by reciprocating the piston 14 in the valve cylinder 2 at high speed and high pressure each time using pressure oil from the hydraulic pump 1 and pressure oil from the accumulator 2. There is a problem in that the moving parts and the contact surfaces of the valve 9 are subject to severe wear.

Therefore, the purpose of this invention is to reduce the number of times the accumulator is used, and to reduce the number of times the accumulator is used, without using an accumulator when pumping ordinary ready-mixed concrete using low pressure, and only when pumping ready-mixed concrete with a poor mix using high pressure. In addition to reducing the number of times, the aim is to reduce the amount of wear that occurs on valves and valve housings.

<Structure of the Invention>'1 In order to achieve the above object, the concrete pump sequence drive device of the present invention uses a hydraulic pump.
).

A main cylinder that is connected to □ via an oil line and drives the concrete pump, a 3-position switching valve for controlling the main cylinder, a concrete valve that switches between suction and pressurization of ready-mixed concrete in the concrete pump, and a concrete valve that controls the concrete pump. Sequence driving of a concrete pump, comprising: a valve cylinder that is connected to a hydraulic pump for control via an oil passage to drive a concrete valve; and an accumulator disposed in an oil passage between the hydraulic pump and the valve cylinder. In the device, an accumulator selection switch for selecting whether or not to use the accumulator is connected in series with an accumulator operating side contact in the accumulator selection switch, and a fluid pressure in an oil passage communicating with the accumulator is set to the accumulator setting pressure. Below, it is turned off and the three-position switching valve for controlling the main cylinder is held in the neutral position to accumulate pressure oil in the accumulator, but when the fluid pressure in the oil passage exceeds the set pressure of the accumulator, it is turned on. and a pressure switch that switches the main cylinder control switching valve to an operating position and causes pressure oil to be fed from the accumulator to the valve cylinder.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

As shown in FIG. 1, a high pressure line 22a connected to the outlet of the hydraulic pump 21 and a low pressure line 2 connected to the tank 24.
Between 2b and 2b is the logic for the valve.
“Through valve 25°・255・25°・25d2, I
t<)Iy2', y , , the rings 26a and 26b are connected. Above valve
1.1. Ada, 63.26b and Hydraulic Boap, 1. )′:l;1 An accelerator 28 is provided in the high pressure line 22a.
There are 17. A check valve 29 is provided between the accumulator 28 and the hydraulic pump 2, j1, and the check valve 2
9 prevents the pressure oil accumulated in the accumulator 28 from flowing back. Check valve 29 above
1 and the hydraulic pump 21, a main cylinder logic is connected between the high pressure line 22a and the low pressure line 22b.
V valve 31a, 3 lb, 31c,
The main serial i adapter 32.42 is connected via 31d. It is shown in Figure 2.
1, the main cylinder 32 is equipped with a cylindrical concrete plate 34 having a larger diameter than the main cylinder 32.
The piston 34a of the concrete pump 34 is caused to reciprocate by the main cylinder 32. The main cylinder 32 and concrete pump 34
The other ends of the double cylinders 32, 42 are connected to each other by a connecting passage 35, and one end of both concrete pumps 34, 44 is connected to a concrete hopper (not shown). Connected to the exit. A valve 36 is provided at the outlet. By opening and closing the valve 36, fresh concrete in the concrete hopper is sucked into the concrete pump 34, 44, or the suction is stopped. Further, as shown in FIG. 1, the main cylinder control pilot switching valve 38 is a three-position switching valve, and the pilot chambers 38a and 38b at both ends are connected to the valve cylinder 2.
6a and 26b through pilot lines 39.4L, and the valve cylinders 26a and 26b operate to the end of their stroke and increase the pressure, thereby switching from the neutral position to a predetermined symbol position. It controls the operation of 32.42. Further, a three-position switching valve 45 for controlling the main cylinder is connected between the high pressure line 22a and the low pressure line 22b and the pilot switching valve 38 for controlling the main cylinder.
controls the operation of the Further, the valve control pilot switching valve 46 is a two-position switching valve, and pilot chambers 46a and 46b at both ends thereof are respectively connected to the main cylinder 42.32 via a logic valve 48.49. A valve control switching valve 54 is connected to pilot lines 51 and 52 between the valve control pilot switching valve 46 and the high pressure and low pressure lines 22a and 22b. The valve control switching valve 54 is a three-position switching valve, and controls the opening and closing of the valve 36. A pressure switch PS is connected between a pilot line 51 and a pilot line 52 between the valve control switching valve 54 and the high pressure and low pressure lines 22a and 22b. Note that 70, 70, and 70 are check valves, and 71 is a relief valve.

A contact PS of the pressure switch PS is provided in a relay circuit shown in FIG. 3 in a control panel (not shown). That is, in the relay circuit, the power line 61a and the common contact C1 of the accumulator selection switch 62 are connected, and the accumulator selection switch 62
The relay coil R1 is connected between the accumulator non-operating contact B and the power line 61b, while the connection point 6 between the relay coil R1 and the accumulator non-operating contact B
4 and the accumulator operating side contact A of the accumulator selection switch 62, there is a contact P of the pressure switch PS.
S is connected.

In addition, while connecting the power supply line 1a and the common contact C2 of the concrete pump drive switch 65, a relay coil R3 is connected between the normal rotation side contact E of the concrete pump drive switch 65 and the power line 61b, and the concrete pump drive switch 65 also connects a relay coil R3. A relay coil R2 is connected between the reverse rotation side contact F of the drive switch 65 and the power supply line 61b.

In addition, a relay contact r is connected between both power lines 61a and 161b.
2 and one coil S3 of the valve control switching valve 54 are connected in series. The above relay contact r2 and the above coil S
1 between the connection point 66 between 3 and the power line 611b.
contact r1 and main cylinder control
One coil S2 of the 13-position switching valve 45 is connected in series 'i', while the above 1
contact r2 and power line 261
The relay contact r3, the relay contact rl, and the other coil SL of the three-position switching valve 45 for controlling the main cylinder are connected in series between the connection point 68 between the main cylinder a and the power line 61b. Furthermore, the relay contact r
)1゛; Connection point 69 between 3 and relay contact r1 and power line
11:) The other side of the valve control switching valve 54 is
-1;) coil S4 is connected.
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In a single-acting device, first, when ordinary ready-mixed concrete is sucked in and pumped through a concrete pump, ;
l(Therefore, there is no need to use the accumulator 28. Also, the accumulator of the relay circuit shown in Fig. 3, ・(
- Connect the common contact C1 of the selection switch 62 and the Akicomulator non-operating side contact B. , relay coil R1 is energized and relay contact rl is turned on. On the other hand, in order to cause the concrete pump 34, 44 to rotate in the normal direction, the common contact C2 and the normal rotation side contact E of the concrete pump drive switch 65
Connect with. Relay coil R3 is energized and relay contact r3 is turned on. As a result, one coil S1 of the three-position switching valve 45 for controlling the main cylinder is excited, and one coil S4 of the switching valve 54 for valve control is excited.

As shown in FIG.
On the other hand, the valve control switching valve 54 is switched from the normal position to the symbol position v4. At this time, the pressure oil discharged from the hydraulic pump 21 is fed to the high pressure line 22a, and this high pressure is transmitted through the pilot line 51 to the valve control switching valve 54 located at the symbol position v4. On the other hand, since the valve control pilot switching valve 46 has been switched to the symbol position v5, the high pressure is applied to the pilot line 51. Valve control switching valve 54 in symbol position V4, symbol position v
The logic valves 25 for the first and third valves from the upstream side in the figure are connected via the valve control pilot switching valve 46 located at 5.
It is transmitted to the spring chamber SSS of a and 25c. Then, the logic valves 25a and 25c are closed. on the other hand,
Logic valve 2 for the second and fourth valves from the upstream side in the diagram
The spring chambers S18 of 5b and 25d are the pilot switching valve 46 for valve control located at the symbol position v5, and the spring chamber S18 is located at the symbol position v4.
Valve control switching valve 54 and pilot line 52
The logic valves 25b and 25d are opened because they are connected to the low pressure line 22b through the valves. the result,
High-pressure oil in the high-pressure line 22a is supplied to the valve cylinder 26b via the valve logic valve 25d, and the valve cylinders 26a and 26b operate to operate the valve 36'!
'716・807・'<)Ltf>')>'12
6bh<.

When operated to the stroke end, the valve cylinder 26b
Since the pressure is approximately as high as the discharge pressure of the hydraulic pump 2I, this high pressure is transmitted to the pilot chamber 38b of the main cylinder control pilot switching valve 38 via the pilot line 41, and the main cylinder control The pilot switching valve 38 is switched from the normal position to the symbol position v6. As mentioned above, since the three-position switching valve 45 for controlling the main cylinder is switched to the symbol position Vt, the high pressure from the high pressure line 22a is transferred to the pilot line 81.
．． The second and fourth valves from the upstream side in the figure
This is transmitted to the spring chamber S18 of the main cylinder logic valve 31b, 31d. Then, the main cylinder logic valves 31b and 31d are closed. On the other hand, the first and third main cylinder logic valves 31a and 31 from the upstream side in the figure
The spring chamber SSS of c is connected to the low pressure line 22b via the main cylinder control pilot switching valve 38 located at the symbol position v6, the 3-position switching valve 45 for main cylinder control located at the symbol position v1, and the pilot line 82. , the main cylinder logic valves 31a and 31c are opened. As a result, high pressure oil from the high pressure line 22a is supplied to the main cylinder 32 via the main cylinder logic valve 31a, and the pistons 34a and 44a shown in FIG. While the fresh concrete is sucked into the concrete pump 34, it is pumped out from the concrete pump 44.

・) Next, we will introduce the problem of low-moisture aggregates that are difficult to pump.
) (1,: Mixed ready-mixed concrete to concrete pump 34.44
, when suction 5 = 1" and pumping 7
A°7・7'1y-y'yya:
1j sleeve with i-switch PS set pressure 120 Kg/cm2.

shall be. Then, the discharge pressure of the hydraulic pump 21 is t
Q□: When the weight is less than 20 Kg/c+n, the relay circuit shown in Fig. 3 is connected to the common contact of the road accumulator selection switch 62.
・)': Even if CI and accumulator operating side contact A are connected,
9) j, -t, ya8i? %PS(7
) Tsusada,, Kayo 120 Kg/. .・
:;1)・ Since relay coil R1 is set to
:, 11: Because the contact PS of the switch PS does not turn on,
□11. Without excitation, relay contact RL is turned off and the main cylinder is turned off.
・;1:: :[ One pilot chamber of the 3-position switching valve 45 for control
While the coil Sl of the pin 45a is de-energized, the common contact C2 of the concrete pump drive switch 65 is connected to the normal rotation side contact E, so the relay coil R3 is energized and the relay contact r3 is turned on. One pilot chamber 54 of the valve control switching valve 54. Relay S4 of a remains energized. As a result, the three-position switching valve 45 for main shilling control moves from the symbol position v1 to the normal position V. On the other hand, the valve control switching valve 5
4 is held at symbol position v4.

Furthermore, since the main cylinder control pilot switching valve 38 is held at the symbol position v6 as described above, the high pressure from the high pressure line 22a is transferred to the pilot line 811.
Normal position V. All main cylinder logic valves 31a, 31b are connected via a three-position switching valve 45 for main cylinder control located at symbol position v6 and a pilot switching valve 38 for main cylinder control located at symbol position v6.

It is transmitted to the spring chambers s, s, sl, s of the main cylinder logic valves 31a, 3l, 31c, 31d.
b, 31c.

31d is closed. Then, the pressure oil discharged from the hydraulic pump 21 is not supplied to the main cylinder 32.42, the main cylinder 32.42 is in a stopped state, and the pressure oil is accumulated in the accumulator 28. When the discharge pressure of the hydraulic pump 2I exceeds 120 Kg/cm', the contact PS of the pressure switch PS shown in FIG. 3 is turned on, so the relay coil R1 is energized and the relay contact r1 is turned on. Since the common contact C2 of the concrete pump drive switch 65 is connected to the normal rotation side contact E, the relay coil R3 is energized and the relay contact r3 is turned on to switch one side of the three-position switching valve 45 for main shilling control. While the coil Sl is energized, one coil S4 of the valve control switching valve 54 remains energized. As a result, the three-position switching valve 45 for main shilling control switches from the normal position vo to the symbol position v1, while the valve control switching valve 54 is held at the symbol position v4.

As a result, the high pressure in the high pressure line 22a passes through the pilot line 51 to the valve control switching valve 54 at the symbol position v4, and the valve control valve at the symbol position v5.
The logic valves 25a for the first and third valves from the upstream side in the figure are connected via the nib control pilot switching valve 46.
This is transmitted to the spring chamber S18 of the valve 125c, and the valve logic valves 25a and 25c are closed. On the other hand, logic valves 25b and 25 for the second and fourth valves from the upstream side in the figure
The spring chamber SSS of d is connected to the low pressure line 22b via the valve control pilot switching valve 46 at the symbol position v5, the valve control switching valve 54 at the symbol position v4, and the pilot line 52, so that the valve logic valve 25b is connected to the low pressure line 22b through the pilot line 52. , 25d are open. For this reason, the pressure oil accumulated in the accumulator 28 is suddenly transferred to the logic valve 25 for the valve.
d to the valve cylinder 26b and the valve 3
6 switches at high speed.

On the other hand, as described above, one coil S1 of the 3-position switching valve 45 for main shilling control is energized, and the 3-position switching valve 45 for main shilling control is in the normal position V.

On the other hand, the high pressure in the valve cylinder 26b is transmitted to the pilot chamber 38b of the main cylinder control pilot switching valve 38, so the main cylinder control pilot switching valve 38 is switched to the symbol position v6. I'm awake.

Also, the high pressure from the high pressure line 22a is transferred to the pilot line 81. 2 from the upstream side in the figure via the 3-position switching valve 45 for main cylinder control located at symbol position ■1 and the pilot switching valve 38 for main cylinder control located at symbol position v6.
Logic valves 31b and 31d for the 4th and 4th main cylinders
), the main cylinder logic valves 31b and 31d are closed, while the spring chambers S of the first and third main cylinder logic valves 31a and 31c from the upstream side in the figure are S is the main cylinder control pilot at symbol position v6, tnm No. 381
．． Two tL4ii! ! V1. E Ah, □tsu1. That's it
3-position switching valve 45 for i control, pilot line 8
2 to the low pressure line 22a, the main cylinder logic valves 32a, 32c are open. The pressure oil from the main hydraulic pump 2I is connected to a high pressure line 22a,
Main cylinder 32 via main cylinder logic valve 31a
is supplied to the pistons 34a1 and 34b, and the pistons 34a1 and 44b operate. o
1) Concrete bong at the same time as inhaling fresh concrete) □:,
.

The main cylinder 32 that pumps the fresh concrete from the pipe 44
The high pressure is transmitted to the spring chamber of the logic valve 49 via the pilot line 84, and the logic valve 49 is closed. Furthermore, when the piston 44a of the concrete pump 44 reaches the stroke end, the pressure inside the main cylinder 42 increases, so this high pressure is transferred to the pilot line 85,
The signal is transmitted to the pilot chamber 46a of the valve control pilot switching valve 46 via the logic valve 48, and the valve control pilot switching valve 46 is switched from the symbol position v5 to the symbol position v7. As a result, logic valve 2 for valve
5b and 25d are closed. On the other hand, logic valve 2 for valve
5a and 25c are open. After the pressure oil from the hydraulic pump 21 is accumulated in the accumulator 28, the accumulated pressure oil is supplied at once to the cylinder valve 26a via the valve logic valve 25a. Valve 36 switches at high speed. On the other hand, the high pressure in the valve cylinder 26a is transmitted to the pilot chamber 38a of the main cylinder control pilot switching valve 38 via the pilot line 39.
The main cylinder control pilot switching valve 38 is switched from the symbol position ■6 to the symbol position V8.

As a result, the main cylinder logic valves 31a, 31c are closed, while the main cylinder logic valve 31b is closed.

31d is open. Then, the pressure oil from the hydraulic pump 2I passes through the main cylinder logic valve 31d to the main cylinder 4.
2, the pistons 34a, 44a shown in FIG.
is operated to suck the poorly mixed fresh concrete into the concrete pump 44 through the valve 36, while pumping the fresh concrete from the concrete pump 34.

In this way, since the accumulator 28 is used only in the case of poorly mixed concrete that is difficult to pump, the number of times vibrations and noises generated from the valve 36 and valve cylinders 26a and 26b are reduced when pressurized oil is pumped by the accumulator 28. Not only can the valve cylinder 26a,
The amount of wear on the sliding portion of 26b can be reduced. Furthermore, by making the set pressure of the pressure switch PS variable, the charge pressure of the accumulator 28 can be controlled, and it is possible to deal with various types of raw concrete with poor mix proportions.

Further, when the fresh concrete is to be pumped to a high place or a far place, the fresh concrete can be pumped by using the accumulator 28 in the same way as in the case of the poor mix of raw concrete described above.

<Effects of the Invention> As is clear from the above description, the concrete pump sequence drive device of the present invention includes a hydraulic pump, a main cylinder, a 3-position switching valve for controlling the main cylinder, a concrete valve, a valve cylinder, an accumulator, moreover,
Equipped with an accumulator selection switch that selects whether or not to use an accumulator, and a pressure switch that operates based on the relationship between the set pressure of the accumulator and the fluid pressure in the oil line, it is possible to transfer raw concrete with a poor mix that is difficult to pump by using a concrete pump. The accumulator can be used only for pressure feeding, which reduces the number of vibrations and noises generated from valves, valve cylinders, oil passages, etc. when pressure oil is fed by the accumulator, and also reduces the number of vibrations and noises generated from the valve cylinder's sliding parts. It can reduce the amount of wear on the contact surface of the valve.

[Brief explanation of the drawing]

1'a'"""10°＞') ')-Lt!77'c7
)y-,,''to'-(D''Dint, !21ffl
+"ty't:zy" i Schematic diagram showing a concrete pump and valve, 3rd figure is a relay circuit diagram, and 4th figure is a circuit diagram of a conventional concrete pump sequence drive device.
1゜21...Main hydraulic pump, 26a, 26b
・・・Valve ：、：”Cylinder・
28-°° Achiemulator・ 32・42°°°l,
Main cylinder, 34.44... concrete pump,
:□1: 36... Valve, 38... 3-position linear switching valve for main cylinder control, 62... Accumulator selection switch, PS
', 7' L, ya, ita.
；□、：［）１′・Patent applicant Kyokuto Kaihatsu 1 Co., Ltd.
:′.

Claims (1)

[Claims] (1) A main cylinder that is connected to the hydraulic pump via an oil line and drives the concrete pump, a 3-position switching valve for controlling the main cylinder, and a concrete valve that switches between suction and pressure feeding of ready-mixed concrete in the concrete pump; A valve cylinder connected to a hydraulic pump via an oil path to drive the concrete valve to control the concrete valve, and an accumulator disposed in the oil path between the hydraulic pump and the valve cylinder. In a concrete pump sequence drive device, an accumulator selection switch that selects whether or not to use the accumulator, and fluid pressure in an oil path that is connected in series with the accumulator operating side contact of the accumulator selection switch and that communicates with the accumulator. is turned off when the accumulator's set pressure is below, and the 3-position switching valve for controlling the main cylinder is held in the neutral position to accumulate pressure oil in the accumulator, while the fluid pressure in the oil passage is lower than the accumulator's set pressure. The sequence drive device for a concrete pump is characterized by comprising a pressure switch that is turned on to switch the main cylinder control switching valve to an operating position and force-feed pressure oil from the accumulator to the valve cylinder.