JPH0460182B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a safety device for safely performing boom raising and lowering operations in a concrete pump vehicle. <Conventional technology> Conventionally, concrete pump trucks have been equipped with a swivel base between the front operator's cab and the rear pump device, and one end of the base boom is attached to a column attached to the swivel base so as to be able to rise and fall. A tip boom having a longer boom length than the base boom is attached to the other end of the base boom so as to be able to rise and fall freely, and concrete piping is installed along the base boom and the tip boom. When raising and lowering the base boom and tip boom of such a concrete pump vehicle, when the collapsed base boom is raised, the front end of the tip boom may tilt downward and come into contact with the upper part of the driver's cab during the raising. be. Further, when the erected base boom is rotated on the swivel base to be positioned on the driver's cab side and then laid down, the lower end of the base boom may come into contact with the upper part of the driver's cab. In this way, if the base boom or the tip boom comes into contact with the driver's cab, the driver's cab will be damaged. In order to avoid such damage to the operator's cab, conventionally, workers visually monitor the operation of the base boom and tip boom, and when the tip boom is about to hit the top of the cab, they stop the base boom. The tip boom is raised after stopping the raising, and the lowering of the base boom is stopped when the lower end of the base boom is about to come into contact with the upper part of the operator's cab. <Problems to be Solved by the Invention> However, such visual operation of the boom poses a problem in that operational errors can damage the operator's cab, which is dangerous. Furthermore, in addition to the worker who operates the boom, a worker who monitors the operation of the boom is required, resulting in a problem that the number of workers increases. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a safety device for a concrete pump truck that prevents the operator's cab from being damaged by the boom without requiring visual monitoring of the boom. <Means for Solving the Problems> In order to achieve the above object, the safety device for a concrete pump truck of the present invention includes a swivel stand provided between the front driver's cab and the rear pump device, One end of the base boom is attached so as to be able to rise and fall freely on a support that is attached to the base boom, and a tip boom having a longer boom length than the base boom is attached to the other end of the base boom so as to be able to rise and fall, and concrete is attached to the base boom and the tip boom. A safety device for a concrete pump vehicle having piping installed therein, comprising: a first detection means for detecting that the base boom or the tip boom is close to the upper part of the driver's cab; and the base boom is located on the driver's cab side. a second detection means for detecting that the swivel base has been swiveled to a predetermined position; While stopping the operation in the rising direction, the second detection means detects that the swivel base has rotated to a predetermined position, and the first detection means detects that the base boom has approached the upper part of the operator's cab. The present invention is characterized by comprising a control device that stops the movement of the base boom in the direction of lodging when this is detected. <Function> When the tip boom approaches the upper part of the operator's cab, the first detection means detects this, and the control device stops the operation of the base boom in the upright direction based on the signal from the first detection means. let Meanwhile, the swivel base rotates to a predetermined position where the base boom is located on the driver's cab side.
The second detection means detects this, and the base boom approaches the upper part of the operator's cab, and the first detection means detects this.
When the detection means detects the boom, the control device stops the movement of the base boom in the lowering direction based on the signals from the first and second detection means. <Examples> The present invention will be described in detail below with reference to illustrated examples. Figure 1 is a schematic diagram of a concrete pump truck, with 1 being a driver's cab, 2 being a pumping device, 3 being a swivel base,
Reference numeral 5 denotes a column fixed to the swivel base 3, 6 is a base boom whose one end is attached to the column 5 so as to be able to rise and fall, and 7 is a boom that is longer than the base boom 6 and whose one end is attached to the other end of the base boom 6 so as to be able to rise and fall. a first tip boom having a length; 8 a second tip boom having one end attached to the other end of the first tip boom in a freely undulating manner; 1;
0 is concrete piping installed along the base boom 6, the first tip boom 7, and the second tip boom 8. The base boom 6 is attached to the support column 5 at one end and raised and lowered by a hydraulic undulation cylinder 11 attached to the base boom 6 at the other end. Further, the first tip boom 7 is connected to the base boom 6 by links 12 and 13 that are bendably connected to each other, and one end is attached to the base boom 6 and the other end is attached to the link 13. It is raised and lowered by a hydraulic first bending cylinder 15 attached to. Furthermore, the second tip boom 8
are links 16, 1 which are refractably connected to each other.
a hydraulic second bend connected to the first tip boom 7 by 7 and having one end attached to the first tip boom 7 and the other end attached to the connection between the links 16 and 17; It is raised and lowered by the cylinder 19. Further, a limit switch SW11 as a first detection means is attached to the upper part of the operator's cab 1, and this limit switch SW11 is normally in the "OFF" state, and the limit switch SW11 is normally in the "OFF" state.
When the front boom 7 comes into contact with this limit switch SW11, it is turned "ON". Further, a limit switch SW12 is installed as a second detection means for detecting the rotational position of the swivel base 3.
12 is normally in the "OFF" state, and becomes "ON" when the base boom 6 is located on the driver's cab 1 side and the swivel base 3 is rotated to a position where it will interfere with the driver's cab when lowered. It's becoming like that. Furthermore,
There is a limit switch on the top of the pump device 2.
SW13 is attached, and this limit switch SW13 is normally in the "OFF" state, and the first refraction cylinder 15 is connected to this limit switch SW13.
It is designed to turn "ON" when it comes into contact with 13. Above limit switch SW11, SW12, SW
13 is connected to the control device shown in FIG.
These limit switches SW11, SW12,
The control device controls the undulation cylinder 11 and the first refraction cylinder 15 in response to a signal from the SW 13. The undulation cylinder 11, the first refraction cylinder 1
5. The turning motor for turning the second bending cylinder 19 and the turning table 3 is operated by a hydraulic circuit shown in FIG. In FIG. 3, 29 is a hydraulic pump, 30 is a main solenoid valve, 31 is a solenoid valve that switches the direction of oil supply to the undulating cylinder 11, and 32 is a first bending cylinder 1.
33 is a solenoid valve that switches the direction of oil supply to the second bending cylinder 19; 34 is a solenoid valve that switches the direction of oil supply to the swing motor 35. When the solenoid 31a of the solenoid valve 31 is energized, oil passes through the check valve 40 and moves the undulating cylinder 11 in the extending direction, while when the solenoid 31b of the solenoid valve 31 is energized, the oil passes through the check valve 41 and moves the undulating cylinder 11. move in the direction of shrinking. Furthermore, when the solenoid 32a of the solenoid valve 32 is energized, the oil passes through the check valve 43 and moves the first bending cylinder 15 in the direction of contraction, while when the solenoid 32b of the solenoid valve 32 is energized, the oil passes through the check valve 43. 1st refraction cylinder 1
5 in the extending direction. Furthermore, when the solenoid 33a of the solenoid valve 33 is energized, the oil passes through the check valve 45 and operates the second bending cylinder 19 in the direction of contraction.
When b is excited, oil passes through the check valve 44 and moves the second bending cylinder 19 in the extending direction. Note that the rotation direction of the swing motor 35 can be switched by switching the excitation of the solenoids 34a and 34b of the solenoid valve 34. The electromagnetic valves 31, 32, 33, and 34 are controlled according to a sequence circuit of a control device shown in FIG. In Fig. 4, 41 and 42 are power lines, S
Reference numeral 11 denotes a changeover switch for operating the elevation of the base boom 6, S12 a changeover switch for operating the elevation of the first tip boom 7, and S13 a changeover switch for operating the elevation of the second tip boom 8. , S
14 is a changeover switch for operating the rotation of the swivel base 3. The above changeover switch S11 is connected to the relay coil CR1.
1 side, relay coil CR11 is energized and normally open contact R11 of this relay coil CR11
-2a becomes "ON" and the solenoid 31a is excited. Then, the undulating cylinder 11 moves in the extending direction, and the base boom 6 moves in the rising direction. On the other hand, when the changeover switch S11 is turned to the relay coil CR12 side, the relay coil CR12 is excited, the normally open contact R12-2a of this relay coil CR12 is turned "ON", and the solenoid 31
b is excited. Then, the undulation cylinder 11
moves in the direction of contraction, and the base boom 6 moves in the direction of lodging. Also. When the above changeover switch S12 is set to the relay coil CR13 side, the relay coil CR13
is excited, the normally open contact R13-2a of this relay coil CR13 turns "ON", and solenoid 3
2a is excited. Then, the first bending cylinder 15 moves in the direction of contraction, and the first tip boom moves in the direction of standing up. On the other hand, when the changeover switch S12 is turned to the relay coil CR14 side, the relay coil CR14 is excited, and this relay coil CR14
The normally open contact R14-2a is turned "ON", and the solenoid 32b is energized. Then, the first bending cylinder 15 moves in the extending direction, and the first tip boom 7 moves in the lodging direction. Moreover, when the above-mentioned changeover switch S13 is placed on the relay coil CR15 side,
Relay coil CR15 is energized, and normally open contact R15-2a of this relay coil CR15 is “ON”.
Therefore, the solenoid 33b is energized. Then, the second bending cylinder 19 moves in the extending direction, and the second tip boom 8 moves in the rising direction. on the other hand,
The above changeover switch S13 is connected to the relay coil CR16.
When placed in the side, relay coil CR16 is energized,
Normally open contact R16-2 of this relay coil CR16
a becomes "ON" and the solenoid 33a is energized. Then, the second bending cylinder 19 moves in the direction of contraction, and the second tip boom 8 moves in the direction of lodging. Further, when the changeover switch S14 is turned to the relay coil CR17 side, the relay coil CR17 is energized, and the normally open contact R17-2a of this relay coil CR17 is turned "ON", and the solenoid 34 is energized. Then, the swing motor 35 rotates in a predetermined direction, and the swivel base 3 rotates in a predetermined direction.
On the other hand, the changeover switch S14 is connected to the relay coil.
When inserted into the CR18 side, relay coil CR18 is excited, and the normally open contact R of this relay coil CR18
18-2a turns "ON" and solenoid 34b is energized. Then, the swing motor 35 rotates in a direction opposite to the predetermined direction, and the swivel base 3 rotates in a direction opposite to the predetermined direction. Next, limit switches SW11, SW12,
The operation of the above-mentioned sequence circuit when the SW 13 is operated will be explained with respect to each state of the boom raising and lowering operation shown in FIG. FIG. 2a shows a state in which the first bending cylinder 15 contacts the limit switch SW13 and the limit switch SW13 is turned "ON" when the base boom 6 is laid down and the boom is retracted.
In this case, the lowering operation of the base boom 6 is stopped, and the raising operation of the first tip boom is prohibited. That is, when the changeover switch S11 is placed on the relay coil CR12 side and the solenoid 31b is energized to lower the base boom 6, the limit switch SW13 is turned "ON". Then, the relay coil CRw is excited, and the normally closed contacts Rw-1b and
Rw-2b becomes "OFF". Normally closed contact above
When Rw-1b becomes “OFF”, the relay coil
CR12 becomes de-energized and relay coil CR12
The normally open contact R12-2a becomes "OFF".
Therefore, the solenoid 31b is de-energized and the lowering operation of the base boom 6 is stopped. On the other hand, when the normally closed contact Rw-2b is turned "OFF", the relay coil CR13 is not energized even if the changeover switch S12 is placed on the relay coil CR13 side, so the normally open contact R13- of the relay coil CR13
2a remains "OFF", so the solenoid 32a is not energized, and the raising operation of the first tip boom is prohibited. FIG. 2b shows when the base boom 6 is erected,
The front end of the first boom 7 is a limit switch.
Contact SW11, limit switch SW11
Indicates the state where is “ON”. In this case, the raising operation of the base boom 6 is stopped and the first
The lowering operation of the tip boom 7 is prohibited. That is, when the changeover switch S11 is placed on the relay coil CR11 side and the solenoid 31a is energized to raise the base boom 6, the limit switch SW11 is turned "ON". Then, the relay coil CRx is energized, and the normally closed contacts Rx-1b and Rx-
2b becomes “OFF”. Normally closed contact Rx-1 above
When b becomes "OFF", relay coil CR11 becomes de-energized, and normally open contact R11-2a of relay coil CR11 becomes "OFF". Therefore,
The solenoid 31a is de-energized and the base boom 6
Stops standing up. On the other hand, when the normally closed contact Rx-2b is turned "OFF", the changeover switch S12 is switched to the relay coil.
Since the relay coil CR14 is not excited even if it is inserted into the CR14 side, the normally open contact R14-2a of the relay coil CR14 remains “OFF”.
Therefore, the solenoid 32b is not energized, and the lowering operation of the first tip boom is prohibited. Fig. 2c shows a case where the lower end of the base boom 6 comes into contact with the limit switch SW11 when the base boom 6 is laid down after the swivel base 3 has been swiveled to a predetermined position where the base boom 6 is located on the driver's cab 1 side. The limit switch SW11 and the limit switch SW12 are "ON". In this case, the lowering operation of the base boom 6 is stopped. That is, after the limit switch SW12 is turned "ON" by the rotation of the swivel base 3, the changeover switch S11 is placed on the relay coil CR12 side, the solenoid 31b is energized, and the base boom 6 is turned on.
When the machine is laid down, limit switch SW11 turns "ON". Then, the relay coil
CRz is energized and normally open contact of relay coil CRz
Rz-1a becomes “ON” and normally closed contact Rz-1b
becomes “OFF”. When the above normally open contact Rz-1a turns “ON”, the relay coil CRy is energized,
Normally closed contact Ry-1b of relay coil CRy becomes “OFF”, relay coil CR12 becomes de-energized, and normally open contact R of relay coil CR12 becomes “OFF”.
12-2a becomes "OFF". Therefore, the solenoid 31b is de-energized and the lowering operation of the base boom 6 is stopped. On the other hand, the above normally closed contact Rz
-1b becomes “OFF”, relay coil CRx
is de-energized and the normally closed contact Rx-1b of the relay coil CRx becomes "ON", so by putting the selector switch S11 into the relay coil CR11 side, the base boom 6 can be raised and lowered, as shown in FIG. The operation of raising the base boom 6 is not prohibited due to the operation of the limit switch SW11 as in b. FIG. 2d shows that when the first tip boom 7 is raised with the base boom 6 slightly raised, the first bending cylinder 15 is lowered and the limit switch is activated.
Contact SW13, limit switch SW13
Indicates the state where is “ON”. In this case, the raising operation of the first tip boom is stopped, and the lowering operation of the base boom 6 is prohibited. That is, when the changeover switch S12 is placed on the relay coil CR13 side and the solenoid 32a is energized to raise the first tip boom 7, the limit switch SW13 is turned "ON". Then, the relay coil CRw is energized, and the normally closed contacts Rw-2b and Rw-1 of the relay coil CRw are energized.
b becomes “OFF”. Normally closed contact Rw-2b above
When the relay coil CR13 becomes "OFF", the relay coil CR13 becomes de-energized, and the normally open contact R13-2a of the relay coil CR13 becomes "OFF". Therefore,
The solenoid 32a is de-energized, and the raising operation of the first tip boom 7 is stopped. On the other hand, when the normally closed contact Rw-1b is turned "OFF", the relay coil CR12 is not excited even if the changeover switch S11 is placed on the relay coil CR12 side.
Normally open contact R12-2a of relay coil CR12
remains "OFF", so the solenoid 31b is not energized, and the lowering operation of the base boom 6 is prohibited. The control of the raising and lowering of the second tip boom 8 by the second bending cylinder 19 is performed independently of the operations of the limit switches SW11, SW12, and SW13. Table 1 summarizes the relationship between the limit switch operation and boom operation described above.

[Table] In Table 1 above, ○ indicates operation is possible, × indicates operation is not possible, and when limit switch SW11 is activated,
The raising of the base boom 6 and the lowering of the first tip boom become inoperable. On the other hand, limit switch SW13
When this is activated, the lowering of the base boom 6 and the raising of the first tip boom are no longer activated. Furthermore, if the limit switches SW11 and SW12 are activated together, the base boom 6 will not be able to be lowered. In this way, when the base boom 6 or the first tip boom 7 comes into contact with the limit switch SW11, the movement of the base boom 6 or the first tip boom 7 in the contact direction is stopped or prohibited. Therefore, the driver's cab 1 will not be damaged. Also, the first refraction cylinder 15 is a limit switch.
Since the lowering operation of the base boom 6 and the raising operation of the first tip boom are stopped or prohibited when it comes into contact with the SW 13, the pump device 2 is not damaged. In the above embodiment, the control device was configured with a sequence circuit, but the limit switches SW11 and SW1
2. The signal from the SW 13 may be configured by software of a microcomputer input via an interface. <Effects of the Invention> As is clear from the above, the safety device for a concrete pump truck of the present invention includes a first detection means for detecting that the base boom or the tip boom is close to the upper part of the operator's cab; a second detection means for detecting that the swivel base has been rotated to a predetermined position located on the driver's cab side; , while the movement of the base boom in the upright direction is stopped, the second detection means detects that the swivel base has rotated to a predetermined position, and the first detection means detects that the base boom is in the operator's cab. The system is equipped with a control device that stops the movement of the base boom in the direction of collapse when it detects that the boom is close to the top, so there is no need for a worker to monitor the boom, and the boom can be controlled by the base boom or tip boom. Damage to the driver's cab can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a concrete pump truck equipped with a safety device for a concrete pump truck according to an embodiment of the present invention, and FIG. FIG. 3 is a diagram showing a hydraulic circuit for operating the boom of the concrete pump vehicle, and FIG. 4 is a circuit diagram of the control device in the above embodiment. 1... Driver's cab, 2... Pump device, 3... Swivel base, 5... Support column, 6... Base boom, 7... First
Tip boom, 8...Second tip boom, 10...Concrete piping, SW11, SW12, SW13...
...limit switch.

Claims (1)

[Scope of Claims] 1. A swivel base is provided between the front driver's cab and the rear pump device, one end of the base boom is attached to a column attached to the swivel base so as to be able to rise and fall, and the other end of the base boom is A safety device for a concrete pump truck, in which a tip boom having a longer boom length than the base boom is attached to the base boom so as to be able to rise and fall freely, and concrete piping is installed along the base boom and the tip boom, a first detection means for detecting that the base boom has approached the upper part of the operator's cab; a second detection means for detecting that the swivel base has been rotated to a predetermined position where the base boom is located on the operator's cab side; When the first detection means detects that the tip boom approaches the upper part of the operator's cab, the operation of the base boom in the upright direction is stopped;
When the second detection means detects that the swivel base has rotated to a predetermined position and the first detection means detects that the base boom approaches the upper part of the operator's cab, A safety device for a concrete pump truck, characterized by comprising a control device for stopping operation in the direction of collapse.