JPH042151B2 - - Google Patents

Description

Detailed Description of the Invention <Industrial Application Field> The present invention provides a concrete system that can reduce vibrations and noise generated when sucking and pumping ready-mixed concrete by driving a concrete pump and valve cylinder according to the condition of the ready-mixed concrete. This invention relates to a sequence drive device in a pump truck.

<Prior art> As shown in FIG. 5, a conventional sequence drive device in a concrete pump vehicle stores pressure oil from a hydraulic pump 1 in an accumulator 2, and the pressure in the accumulator 2 is equal to the set pressure of a sequence valve 4. When the above occurs, the sequence valve 4 is activated and pressure oil from the hydraulic pump 1 is supplied to one of the main cylinders 6 via the sequence valve 4 and the main cylinder control switching valve 5, and this main cylinder 6 is activated. At the same time as fresh concrete is pumped from one concrete pump 8, fresh concrete is sucked into the other concrete pump 8 via the concrete valve 9. Then, when the valve control switching valve 11 is switched, the pressure oil in the accumulator 2 is suddenly discharged. The concrete valve 9 is instantaneously switched by being supplied to the valve cylinder 12 via the valve control switching valve 11,
Then, when the pressure of the accumulator 2 reaches the set pressure of the sequence valve 4 again, the main cylinder 6 operates to suck fresh concrete into one concrete pump 8 via the concrete valve 9, and at the same time pump fresh concrete from the other concrete pump 8. There is something to do.

<Problems to be Solved by the Invention> However, in the sequence drive device for the concrete pump vehicle, the concrete valve 9 is switched at high speed and under high pressure using the accumulator 2 each time the concrete valve 9 is switched. Sometimes there are problems with vibration and noise. Furthermore, the concrete valve 9 is switched by using the pressure oil from the hydraulic pump 1 and the pressure oil from the accumulator 2 to the valve cylinder 12.
Since the piston 14 is reciprocated at high speed and high pressure each time, there is a problem in that the sliding portion of the piston 14 and the contact surface of the concrete 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, by not using the accumulator when pumping ordinary ready-mixed concrete using low pressure, and only when pumping ready-mixed concrete with a poor mix using high pressure. The objective is to reduce the number of times and the amount of wear that occurs on concrete valves and valve housings.

<Structure of the Invention> In order to achieve the above object, a sequence drive device in a concrete pump vehicle of the present invention is connected to a hydraulic pump via an oil path, and controls a main cylinder that drives the concrete pump and the main cylinder. A 3-position switching valve for main cylinder control,
A concrete valve that switches between sucking and pressurizing fresh concrete in the concrete pump, a valve cylinder that is connected to a hydraulic pump via an oil line to control the concrete valve and drives the concrete valve, and a valve that controls the valve cylinder. In a sequence drive device for a concrete pump vehicle, comprising a control switching valve and an accumulator disposed in an oil path between the hydraulic pump and the valve cylinder, an accumulator that selects whether or not to use the accumulator. a selection switch; and a pressure switch which is actuated by the fluid pressure of the oil passage leading to the accumulator and has a contact connected in series with the accumulator operation side contact of the accumulator selection switch, the pressure switch being operated by the fluid pressure of the oil passage leading to the accumulator, the By turning off the pressure switch at , the valve control switching valve is held in the neutral position and the pressure oil from the hydraulic pump is accumulated in the accumulator, while the pressure is turned off at a pressure higher than the set pressure of the accumulator. The present invention is characterized in that when the switch is turned on, the valve control switching valve is switched to the operating position, and pressure oil is force-fed from the accumulator to the valve cylinder.

<Examples> The present invention will be described in detail below with reference to illustrated examples.

As shown in FIG. 1, logic valves 25a, 25b, 25c, and 25d are connected to a valve cylinder 26a between a high pressure line 22a connected to the outlet of the hydraulic pump 21 and a low pressure line 22b connected to the tank 24. , 26b are connected. The valve cylinders 26a, 26b and the hydraulic pump 21
The high pressure line 22a between the accumulator 2
There are 8. A check valve 29 is provided between the accumulator 28 and the hydraulic pump 21, and the check valve 29 prevents the pressure oil accumulated in the accumulator 28 from flowing back. Main cylinder logic valves 31a, 31b, 31c, 31 are connected between the high pressure line 22a and the low pressure line 22b between the check valve 29 and the hydraulic pump 21.
The main cylinders 32 and 42 are connected via d. As shown in FIG. 2, a cylindrical concrete pump 34 having a larger diameter than the main cylinder 32 is connected to the main cylinder 32, and the main cylinder 32 causes a piston 34a of the concrete pump 34 to reciprocate. . Another main cylinder 42 and concrete pump 4 having the same structure as the above main cylinder 32 and concrete pump 34
4, the other ends of the main cylinders 32, 42 are connected to each other by a connecting passage 35, and one ends of the concrete pumps 34, 44 are connected to the outlet of a concrete hopper (not shown). A concrete valve 36 is provided at the outlet. By opening and closing the concrete valve 36, fresh concrete in the concrete hopper is sucked into the concrete pumps 34 and 44, and the suction is stopped. In addition, as shown in FIG. 1, the main cylinder control pilot switching valve 38
is a three-position switching valve, and the pilot chambers 38a, 38b at both ends are connected to the valve cylinders 26a, 26.
b via pilot lines 39 and 41, respectively, and the valve cylinders 26a and 26b operate to the end of their stroke and increase pressure to switch from the neutral position to a predetermined symbol position, and the main cylinder 32 , 42 are controlled. Furthermore, the three-position switching valve 45 for main cylinder control is connected to the high pressure line 22a and the low pressure line 22a.
b and the above-mentioned main cylinder control pilot switching valve 38
and controls the operation of the main cylinders 32 and 42. Further, the valve control pilot switching valve 46 is a two-position switching valve, and the pilot chambers 46a and 46b at both ends are connected to the logic valve 4.
The main cylinders 42 and 32 are connected to the main cylinders 42 and 32 via cylinders 8 and 49, respectively. 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 concrete valve 36. The switching valve 54 for valve control and the high pressure and low pressure lines 22a and 22b
A pressure switch PS is connected between the pilot line 51 and the pilot line 52. In addition, 70, 70, 70 are check valves,
71 is a relief valve.

Contact PS ₁ of the pressure switch PS is provided in a relay circuit shown in FIG. 3 in a concrete 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 relay coil _R1 is connected between the accumulator non-operating contact B of the accumulator selection switch 62 and the power line 61b. On the other hand, the above relay coil
The contact PS ₁ of the pressure switch PS is connected between the connection point 64 between R ₁ and the contact B on the non-operating side of the accumulator and the contact A on the accumulator operating side of the accumulator selection switch 62.

In addition, while connecting the power line 61a 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 Reverse side contact F of concrete pump drive switch 65 and power line 61b
Relay coil _R2 is connected between.

In addition, between both power supply lines 61a and 61b, there is a relay contact _R2 , a relay contact _R1 , and a valve control switching valve 5.
4 and one coil _S3 is connected in series. A relay contact r3 is connected between the connection point 66 between the relay contact _r2 and the power line 61a and the power line 61b _.
and one coil _S1 of the three-position switching valve 45 for controlling the main cylinder are connected in series, while the connection point 68 between the relay contact _r3 and the coil _S1 and the power line 61b are connected in series. In between, the relay contact _r1 and the other coil _S4 of the valve control switching valve 54 are connected in series. Further, the other coil S ₂ of the three-position switching valve 45 for controlling the main cylinder is connected between the connection point 69 between the relay contact r ₂ and the relay contact r ₁ and the power line 61b.

In the concrete pump sequence drive device having the above configuration, first, when ordinary ready-mixed concrete is sucked in and pumped by the concrete pumps 34 and 44, it is necessary to use the accumulator 28 because ordinary ready-mixed concrete has a high moisture content and is easy to pump. Therefore, the common contact _C1 of the accumulator selection switch 62 of the relay circuit shown in FIG. 3 is connected to the accumulator non-operating side contact B. relay coil
R ₁ is energized and relay contact r ₁ is turned on. on the other hand,
In order to cause the concrete pumps 34, 44 to rotate in the normal direction, the common contact _C2 of the concrete pump drive switch 65 and the normal rotation side contact E are connected. Relay coil _R3 is energized and relay contact _r3 is turned on.
As a result, the three-position switching valve 45 for controlling the main cylinder
One coil S ₁ of the valve control switching valve 54 is excited, and the other coil S ₄ of the valve control switching valve 54 is excited. As shown in FIG. 1, the three-position switching valve 45 for main cylinder control switches from the neutral position, that is, the normal position Vo, to the symbol position _V1 , while the valve control switching valve 54 switches from the normal position Vo to the symbol position V1. Switch to position V4. Then, the high pressure from the high pressure line 22a, that is, as shown in FIG.
A pressure of 60 kg/cm ² is applied to the pilot line 81, the 3-position switching valve 45 for controlling the main cylinder at the symbol position V ₁ , and the pilot switching valve 38 for controlling the main cylinder at the symbol position V ₈ to the upstream side in FIG. Logic valve 3 for the first and third main cylinders from the side
It is transmitted to the spring chambers S and S of 1a and 31c. The main cylinder logic valves 31a, 31c
will be closed. On the other hand, the spring chambers S and S of the second and fourth main cylinder logic valves 31b and 31d from the upstream side in the figure are the main cylinder control pilot switching valve 38 located at symbol position _V8 , and the symbol position _V1.
The main cylinder logic valve 31 is connected to the low pressure line 22b via the main cylinder control 3-position switching valve 45 and the pilot line 82.
b, 31d are open. As a result, high pressure line 2
High pressure oil from 2a is supplied to the main cylinder 42 via the main cylinder logic valve 31d,
The pistons 34a and 44a shown in FIG. 2 operate to suck fresh concrete into the concrete pump 44 via the valve 36, while pumping the fresh concrete from the concrete pump 34. Furthermore, since the valve control switching valve 54 has been switched from the normal position Vo to the symbol position V ₄ , the pressure oil discharged from the hydraulic pump 21 is sent under pressure to the high pressure line 22 a, and this high pressure passes through the pilot line 51. The signal is then transmitted to the valve control switching valve 54 located at the symbol position _V4 . On the other hand, since the pilot switching valve 46 for valve control has been switched to the symbol position V5, the above-mentioned high pressure is transferred to the pilot line 51, the symbol position
Valve control switching valve 54 in position V ₄ , pilot switching valve 46 in symbol position V ₅
It is transmitted to the spring chambers S, S of the logic valves 25a, 25c for the first and third valves from the upstream side in the figure. And the logic valve 25 for the valve
a, 25c are closed. On the other hand, 2 from the upstream side in the diagram
Logic valves 25b and 25 for the third and fourth valves
The spring chambers S and S in d are the pilot switching valve 46 for valve control located at the symbol position _V5 , and the symbol position
Since it communicates with the low pressure line 22b via the valve control switching valve 54 and the pilot line 52 in _V4 , the logic valves 25b and 25d for the valves are
opens. As a result, high pressure oil in the high pressure line 22a is supplied to the valve cylinder 26b via the valve logic valve 25d, the valve cylinders 26a and 26b are operated, and the concrete valve 36 is switched. And the valve cylinder 26b
When the valve cylinder 26b is operated to the end of its stroke, the pressure in the valve cylinder 26b becomes as high as the discharge pressure of the hydraulic pump 21, so this high pressure is passed through the pilot line 88 to the pilot chamber of the main cylinder control pilot switching valve 38. 38b, the main cylinder control pilot switching valve 38
switches from symbol position V ₈ to symbol position V ₆ .

Next, when concrete pumps 34 and 44 are sucking in and pumping fresh concrete with a poor mix that is difficult to pump and contains a lot of aggregate with little moisture, the set pressure of the pressure switch PS is set to 120 kg/cm ² . shall be. Then, the discharge pressure of the hydraulic pump 21 is 120
Kg/cm ² or less, the common contact C ₁ of the accumulator selection switch 62 of the relay circuit shown in Fig. 3
Even if the contact A on the accumulator operating side is connected,
Since the set pressure of pressure switch PS is set to 120Kg/cm ² , relay coil R ₁ is not energized and relay contact R ₁ is OFF because contact PS ₁ of pressure switch PS does not turn on. One coil S ₁ of the 3-position switching valve 45 for controlling the main cylinder
remains energized, while the other coil S ₄ of the valve control switching valve 54 is de-energized because the relay contact r ₁ is off. As a result, the three-position switching valve 45 for controlling the main cylinder is in the symbol position V ₁
On the other hand, the valve control switching valve 54 is switched from the symbol position _V4 to the normal position Vo.
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 81, the main cylinder control valve 38 at the symbol position _V1 . Position switching valve 45, symbol position
Pilot switching valve 3 for main cylinder control located in V ₆
8 to the spring chambers S of the second and fourth main cylinder logic valves 31b and 31d from the upstream side in the figure.
S is transmitted to the logic valve 3 for the main cylinder.
1b and 31d are closed. On the other hand, the main cylinder logic valves 31a and 31c are opened. The pressure oil discharged from the hydraulic pump 21 is then transferred to the high pressure line 2.
2a, is supplied to the main cylinder 32 via the main cylinder logic valve 31a, and is supplied to the main cylinder 32, 42.
operates and pumps out raw concrete with a poor mix. At this time, the high pressure from the high pressure line 22a is applied to all the valve logic valves 25a through the pilot line 51, the valve control switching valve 54 at the normal position Vo, and the valve control pilot switching valve 46 at the symbol position _V5 . , 25b, 25c, 25
The pressure oil from the hydraulic pump 21 is not supplied to the valve cylinders 26a, 26b because the valve logic valves 25a, 25b, 25c, and 25d are all closed. . Similarly, pressurized oil from the hydraulic pump 21 is maintained and accumulated in the accumulator 28 during this period. When the discharge pressure of the hydraulic pump 21 reaches 120 kg/cm ² , the pressure of the pressure oil discharged from the hydraulic pump 21 reaches point H in FIG. 4. In addition, the contacts of the pressure switch PS shown in Figure 3
Since PS ₁ is turned on, relay coil R ₁ is energized and relay contact r ₁ is turned on, and since the common contact C ₂ of the concrete pump drive switch 65 is connected to the normal rotation side contact E, the relay coil R ₃ is energized, relay contact r ₃ is turned on, and the other coil S ₄ of the valve control switching valve 54 is energized. As a result, the valve control switching valve 54 is in the normal position.
Switch from Vo to symbol position V ₄ . Further, the high pressure supplied to the main cylinder 32 passes through the pilot line 100 to close the logic valve 49, while the low pressure passes through the pilot line 101 to open the logic valve 48. switches from symbol position _V5 to symbol position _V7 . As a result, the high pressure in the high pressure line 22a passes through the pilot line 51 to the valve control switching valve 5 at symbol position _V4 .
4. It is transmitted to the spring chambers S, S of logic valves 25b, 25d for the second and fourth valves from the upstream side in the figure through the pilot switching valve 46 for valve control located at the symbol position _V7 , and Logic valves 25b and 25d are closed. On the other hand, logic valves 25 for the first and third valves from the upstream side in the figure
The spring chambers S and S of a and 25c communicate with the low pressure line 22b via the valve control pilot switching valve 46 located at the symbol position V ₇ , the valve control switching valve 54 located at the symbol position V ₄ , and the pilot line 52. Logic valves 25a, 25 for the above valves
c is open. Therefore, 120 kg/cm ² of pressure oil accumulated in the accumulator 28 is supplied to the valve cylinder 26a via the valve logic valve 25a, and the valve 36 is switched at high speed ^. Valve cylinder 26a, 2 at point I
6b reaches the stroke end. Eventually, the pressure drops to point J of 90Kg/ ^cm2 and the pressure switch is turned on.
PS will be turned off. As a result, the timer's relay coil T is de-energized and the normally open switch TA is turned off, and the relay coil _R1 is de-energized and the relay contact _r1 is turned off. Then, the coil S4 becomes de-energized, and the 3-position switching valve 4 for controlling the main cylinder
5 remains at the symbol position _V1 , while the valve control switching valve 54 is switched from the symbol position _V4 to the normal position Vo. In this way, the pressure switch setting pressure is turned on at 120Kg/ ^cm2 ,
Since the valve cylinders 26a and 26b are turned off at 90 kg/cm ² , the valve cylinders 26a and 26b can be sufficiently stroked to the stroke end, and even raw concrete with a poor mix that is difficult to pump can be easily pumped.

Furthermore, since the accumulator 28 is used only in the case of poorly mixed concrete that is difficult to pump, the number of vibrations and noises generated from the concrete valve 36 and valve cylinders 26a and 26b can be reduced when pressure oil is pumped by the accumulator 28. Not only can the valve cylinders 26a, 26b
The amount of wear on the sliding parts 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 fresh concrete of various poor mixes.

Further, even when the ready-mixed concrete is to be pumped to a place far from a high place, the above-mentioned ready-mixed concrete can be pumped using the accumulator 28 in the same way as in the case of the above-mentioned poor mix of ready-mixed concrete.

Further, after the pressure oil from the hydraulic pump 21 is accumulated in the accumulator 28, the pressure oil is immediately caused to flow into the valve cylinders 26a and 26b at once, so the accumulation time of the pressure oil in the accumulator 28 is short, so that the pressure oil from the accumulator 28 is No oil leaks.

<Effects of the Invention> As is clear from the above description, according to the sequence drive device for a concrete pump vehicle of the present invention, a hydraulic pump, a main cylinder, a 3-position switching valve for controlling the main cylinder, a concrete valve, and a valve cylinder are combined. The accumulator and the accumulator selection switch that selects whether or not to use the accumulator are operated based on the relationship between the set pressure of the accumulator and the fluid pressure of the oil passage, and are connected in series with the accumulator operation side contact of the accumulator selection switch. Since the pressure switch is equipped with a pressure switch that has a contact point, only in the case of poorly mixed concrete that needs to be pumped at high pressure, the pressure switch is turned off when the pressure is below the set pressure of the above-mentioned accumulator. is held in the neutral position to accumulate pressure oil from the hydraulic pump in the accumulator. On the other hand, when the pressure exceeds the set pressure of the accumulator, the pressure switch is turned on and the valve control selector valve is switched to the operating position to release pressure oil from the accumulator. Ready-mixed concrete can be pumped by forcing it to flow into the valve cylinder at once and switching the concrete valve. Therefore, according to the present invention, the accumulator can be used only when pumping fresh concrete with a poor mix, which is difficult to pump, from a concrete pump, and the concrete valve, valve cylinder, oil It is possible to reduce the number of vibrations and noises generated from roads, etc., and also to reduce the amount of wear on the sliding parts of valve cylinders and the contact surfaces of concrete valves.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of the concrete pump sequence drive device of the present invention, Fig. 2 is a schematic diagram showing the main cylinder, concrete pump, and concrete valve, Fig. 3 is a relay circuit diagram, and Fig. 4 is a circuit diagram of the concrete pump sequence drive device of the present invention. A diagram showing the relationship between pressure of pressure oil and elapsed time, and FIG. 5 is a circuit diagram of a conventional sequence drive device for a concrete pump. 21... Hydraulic pump, 26a, 26b... Valve cylinder, 28... Accumulator, 32, 4
2... Main cylinder, 34, 44... Concrete pump, 36... Concrete valve, 45...
3-position switching valve for main cylinder control, 54... switching valve for valve control, 62... accumulator selection switch, PS... pressure switch.

Claims (1)

[Scope of Claims] 1. A main cylinder that is connected to a hydraulic pump via an oil line and drives the concrete pump, a 3-position switching valve for controlling the main cylinder that controls the main cylinder, and a main cylinder that controls the ready-mixed concrete in the concrete pump. a concrete valve that switches between suction and pressure feeding; a valve cylinder that is connected to a hydraulic pump via an oil line to control the concrete valve and drives the concrete valve; and a valve control switching valve that controls the valve cylinder; A sequence drive device for a concrete pump vehicle comprising an accumulator disposed in an oil path between the hydraulic pump and the valve cylinder, an accumulator selection switch for selecting whether or not to use the accumulator; a pressure switch actuated by fluid pressure in an oil passage communicating with the accumulator, the pressure switch having a contact connected in series with an accumulator operating side contact of the accumulator selection switch; When the pressure switch is turned off, the valve control switching valve is held in a neutral position and pressure oil from the hydraulic pump is accumulated in the accumulator, while when the pressure switch is turned on when the pressure exceeds the set pressure of the accumulator, A sequence drive device for a concrete pump vehicle, characterized in that the valve control switching valve is switched to an operating position so that pressure oil is force-fed from the accumulator to the valve cylinder.