JP3040592B2 - Multi-stage boom device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multistage boom for slurry transportation such as a concrete pump truck.

[0002]

2. Description of the Related Art The structure and function of a conventional concrete pump truck will be described with reference to FIGS. In the figure, 1
Is a cabin, 2 is a root boom, 3 is a middle boom (previous boom), 4 is a tip boom, 5 is a joint that connects the root boom and the middle boom, 6 is a joint that connects the middle boom and the tip boom, 7, 8 and 9 are hydraulic cylinders for vertically operating the root, middle and tip booms respectively.
11, 12, and 13 are connecting links, 14, 15, and 16 are root booms, intermediate booms, concrete transport pipes along the tip boom, 17 is a tip hose, 18 is a tip hose guide, and 19 supports these boom devices. Gantry 20 that connects the upper gantry 19 and the root boom 2, and 21 is a lower gantry, 22, 23, 2
Reference numerals 4 and 25 denote outriggers that prevent the boom from tipping over and support the vehicle body, and reference numerals 26 and 27 denote concrete cylinders that alternately suck in ready-mixed concrete from a hopper 28.

The ready-mixed concrete sucked into the concrete cylinder is provided with hydraulic pistons 29 and 30 and a piston rod 3
1, 32 and the reciprocating motion of the concrete pistons 33, 34 alternately discharge the fluid to a target location via the transport pipes 35, 14, 15, 16 and the end hose 17. As shown in FIG. 5, the booms 2, 3, and 4 are devices used as a means for pipe transporting ready-mixed concrete supplied from a ready-mixed concrete vehicle (not shown) to an arbitrary location. It can be connected by a variable posture mechanism consisting of 6 and 20 and driven by hydraulic cylinders 7, 8 and 9 to cast concrete in a wide range, and can be easily stored when running as a vehicle by itself. It has become.

[0004] There are two types of concrete pumps, a piston type and a squeeze type, depending on the structure. In concrete pumping, the piston type generates a pulsating flow due to two reciprocating pistons, and the squeeze type uses a plurality of rollers rotating while crushing a rubber tube, causing a pulsating flow in each operating cycle. Occurs. When the concrete pulsating flow passes through the tip hose 17 and is discharged, fluctuations in the momentum of the concrete flow cause the tip hose 1 to change.
7 and propagated to the boom tip to vibrate the boom.

A hydraulic cylinder is sometimes used to suppress the vibration of the boom for the purpose of suppressing the vibration in order to ensure the safety of the work at the tip of the cylinder and to prevent the fatigue safety rate of the boom from lowering. Such a technique for preventing vibration will be described with reference to FIGS. FIG. 7 is a detailed system diagram of the joint section 6 of FIG. 5, and FIG. 8 is a hydraulic system diagram of FIG. 7 and 8, reference numerals 36 and 39 denote electromagnetic switching valves, reference numerals 37 and 40 denote hydraulic pumps, and reference numerals 38 and 41 denote oil tanks. Reference numeral 42 denotes a hydraulic system which comprises an electromagnetic switching valve 36, a hydraulic pump 37, and an oil tank 38, and controls the expansion / contraction operation of the hydraulic cylinder 9 for bending the boom, and 43 denotes an electromagnetic switching valve 39, a hydraulic pump 40, and an oil tank 41. And a hydraulic system for controlling the expansion and contraction operation of the hydraulic cylinder 9 for the vibration control operation of the boom. 44 is a hydraulic piston, 45 is a hydraulic cylinder main body, 46 is a piston rod, 56 is a stroke sensor for detecting the stroke position of the hydraulic cylinder 9, and the other symbols are the same as those in FIG.

In FIGS. 7 and 8, when the hydraulic system 42 operates, the hydraulic system 43 stops, and when the hydraulic system 43 operates, the hydraulic system 42 stops.
Are not operated at the same time and are used by switching,
In the hydraulic systems 42 and 43, the hydraulic pump 3
The high-pressure oil generated by the valves 7 and 40 is supplied to the electromagnetic switching valve 36,
The amount and direction of oil flow into the hydraulic cylinder 9 are controlled by the function of the hydraulic cylinder 9, whereby the hydraulic cylinder 9
Operates.

Incidentally, when the hydraulic cylinder 9 is used for vibration control of the boom at the time of control by the hydraulic system 43, it is often necessary to have only a short operating stroke length range. It is based on the following reason: According to the invention of Japanese Patent Application No. 3-307794, the function of the hydraulic cylinder for vibration suppression is to exert a force for suppressing the vibration of the boom tip, that is, the function of the hydraulic cylinder in vibration suppression. Is to apply a force (impact force) to the boom, rather than to displace the boom, for which a long stroke is not required.
This can be understood from the fact that, for example, when a ball is hit against a wall, a large force (impact force) can be applied to the wall even if the deformation amount (dent amount) of the wall is extremely small.

Next, another conventional vibration suppression technology described in Japanese Patent Application No. 3-307794 is shown in FIGS.
This will be described below. 9 is a system diagram in which a vibration suppression cylinder 147 is attached in place of the link 13 in the joint 6 of FIG. 5, and FIG. 10 is a diagram in which a hydraulic system of a portion related to vibration suppression in FIG. 9 is taken out. is there. 9 and 10, reference numerals 36 and 39 denote electromagnetic switching valves, 37 and 40 denote hydraulic pumps, and 38 and 41 denote oil tanks. Reference numeral 42 denotes a hydraulic system that includes an electromagnetic switching valve 36, a hydraulic pump 37, and an oil tank 38, and controls a telescopic operation of the boom bending hydraulic cylinder 9 for the bending operation of the boom.
9, a hydraulic system that includes a hydraulic pump 40 and an oil tank 41, and controls the expansion and contraction operation of the boom vibration control hydraulic cylinder 147. Reference numeral 144 denotes a hydraulic piston, 145 denotes a hydraulic cylinder main body, 146 denotes a piston rod, 148 denotes a stroke sensor for detecting a stroke position of the hydraulic cylinder 47, and other reference numerals are the same as those in FIG.

In FIGS. 9 and 10, the high pressure oil generated by the hydraulic pump 40 is controlled by the electromagnetic switching valve 39 to control the amount and direction of flow of the oil into the hydraulic cylinder 147. Operating hydraulic cylinder 147 operates. As described in the specification of Japanese Patent Application No. 3-307794, the function of the vibration control hydraulic cylinder 147 is to exert a force for suppressing vibration at the end of the boom.
At the time of the control in 3, when the hydraulic cylinder 147 is used for the purpose of damping the boom, only a short range of the working stroke is often required.

[0010] Generally, oil has properties of compressibility and viscosity, which act as a spring element against pressure in a closed system and respectively act as a damper element due to flow resistance. Equivalent to working. In the vibration control operation of the boom, the hydraulic oil of the closed system in the head-side space 149 and the rod-side space 150 in FIG. It can be expected to work as a spring element to have a large effect on the link.

Therefore, in order to positively utilize the function as the spring element and the damper element, it is often advantageous to increase the volume of the oil in the closed system.

[0012]

The above-mentioned prior art has the following problems. In the conventional devices as shown in FIGS. 7 and 8, the hydraulic oil flowing in the hydraulic systems 42 and 43 is mixed in the hydraulic cylinder 9, so that the oil in the hydraulic system 42 is more contaminated than the hydraulic system 43, for example. In this case, it becomes difficult to prevent the hydraulic system 43 from contaminating the working oil. This is
As described in the specification of Japanese Patent Application No. 3-307794, when an electromagnetic servo valve is used for 39, a problem sometimes arises because the electromagnetic servo valve is vulnerable to oil contamination.

When the hydraulic system 42 is stopped and the hydraulic system 43 is operated to control the hydraulic cylinder 9 for the purpose of damping the boom, if the control system malfunctions, the cylinder 9 malfunctions greatly, The boom can move significantly, which is a major safety issue. Further, in the vibration suppression control by the hydraulic system 43, a position above the stroke position of the hydraulic cylinder may be obtained. Therefore, a high-precision stroke position detecting device 56 may be incorporated in the hydraulic cylinder. However, when a cylinder is used for damping the boom as described above, the stroke of the cylinder is often required to be very small. Therefore, the stroke position of a very small section in a long entire stroke is set to a high value. In order to obtain high accuracy, there are problems in the mounting method of the stroke position detecting device, the stroke positioning within the working range of the stroke position detecting device, and the like.

Further, even if only a very small part of the entire stroke of the cylinder requires high-precision machining in vibration control operation or the like, the conventional example shown in FIGS. There is also a problem that the entire stroke range must be machined with high precision due to restrictions. Furthermore, when a hydraulic cylinder is used for bending the boom, the same hydraulic cylinder cannot be used for vibration suppression at the same time. That is, there is a problem that vibration cannot be controlled during the boom bending operation with one cylinder.

Further, in the conventional apparatus as shown in FIGS. 9 and 10, when a normal hydraulic cylinder is normally used, when a failure occurs in a valve or the like during a vibration control operation, or when the hydraulic piping is damaged. When this occurs, the cylinder may malfunction significantly, which is a serious problem in terms of safety. In order to avoid the above problems by using a cylinder with a short stroke, the volume of the oil in the closed system is reduced, and the function of the hydraulic oil as a spring element and a damper element can be positively used. Absent. SUMMARY OF THE INVENTION It is an object of the present invention to provide a multi-stage boom device capable of suppressing vibration of a boom tip and preventing malfunction of a boom drive cylinder.

[0016]

[Means for Solving the Problems]

(1) A hydraulic cylinder having a structure in which one hydraulic cylinder has a plurality of pistons, that is, a hydraulic cylinder in which a plurality of hydraulic cylinders are vertically connected is used. The plurality of pistons (cylinder portions) are assigned for boom expansion and contraction and boom vibration suppression, and perform dedicated functions.

(2) A cylinder provided with a stopper for limiting the movement is used in a part of the entire stroke of the cylinder.

[0018]

[Action]

(1) Since a plurality of pistons are provided in one cylinder, a structure in which a plurality of independent hydraulic cylinders are connected in series is eliminated, so that oils of a plurality of systems do not mix with each other, and contamination management is facilitated. Become. Also, since the cylinder used for vibration suppression operation is independent of the cylinder used for bending the boom, the stroke length, cylinder diameter (piston diameter) machining accuracy, etc. can be reduced by using the cylinder used for bending the boom. You can design freely without being caught up in. In particular, with regard to the stroke length, the stroke length required for boom damping can be reduced to a minimum, and malfunction of the cylinder when a failure occurs in the control system can be reduced, thereby improving safety. Furthermore, since the boom bending portion and the boom damping portion of the hydraulic cylinder are independent, the boom bending and vibration damping can be performed simultaneously, that is, the vibration damping operation during the boom bending motion can be performed.

(2) Since the oil volume in the cylinder does not become particularly small, the function of the oil as a spring element and a damper element is not reduced. In addition, since the stroke is short at the time of cylinder malfunction, the amount of cylinder malfunction is reduced. Safety is improved.

[0020]

【Example】

First Embodiment A first embodiment of the present invention will be described with reference to FIG. This embodiment uses a hydraulic cylinder having two pistons for bending and damping the slurry transport boom.
, The hydraulic cylinder 9 includes a hydraulic cylinder 47 used for boom bending and a hydraulic cylinder 48 used for boom vibration control. Hydraulic cylinder 47
And 48 are completely independent by a partition 49 and have independent pistons 51 and 54, respectively.

A hydraulic system 42 controls the expansion and contraction of a hydraulic cylinder 47 for the bending operation of the boom, and a hydraulic system 43 controls the expansion and contraction of a hydraulic cylinder 48 for the vibration control operation of the boom. The hydraulic systems 42 and 43 and the hydraulic cylinders 47 and 48 operate independently and separately, and can operate simultaneously. In this embodiment, 1
By making two pistons in one cylinder,
Since it has a structure in which two hydraulic cylinders are connected in series, 2
There is no mixing of two independent oils, which makes contamination management easier. Further, it is not necessary to always use the same hydraulic oil in the two hydraulic systems.

Further, since the cylinder used for vibration damping operation and the like is independent of the cylinder used for bending the boom and the like, the stroke length, cylinder diameter (piston diameter), machining accuracy, etc. It can be designed freely without being bound by the properties of cylinders used for bending and the like. In particular, with regard to the stroke length, the stroke length required for boom damping or the like can be reduced to a minimum, and malfunction of the cylinder when a failure occurs in the control system can be reduced, which is advantageous in terms of safety.

Second, Third, and Fourth Embodiments The second, third, and fourth embodiments of the present invention will be described with reference to FIGS. 2, 3, and 4. FIG. In these embodiments, the boom damping hydraulic cylinder 147 in FIG. 9 is provided with a stopper 151 for restricting the movement of the hydraulic piston 144 in the cylinder, and FIG. Stoppers 151a and 1 on both sides of the piston 144
FIG. 3 shows a stopper 151c inside the hydraulic cylinder body 145 and a stopper 15c on the piston rod 146.
FIG. 4 shows a case where a stopper 151 e is formed between the hydraulic cylinder main body 145 and the piston rod 146.

In each of the above embodiments, the volume of the oil inside the hydraulic cylinder body 145 does not particularly decrease, so that the function of the oil as a spring element and a damper element does not decrease. However, the movable range of the piston 144 is only the gap between the stoppers 151, and the amount of cylinder malfunction at the time of cylinder malfunction is small, and the safety is high. In each of the above embodiments, the stoppers are provided on both the extension side and the contraction side of the hydraulic cylinder. However, any one of them may be provided as necessary.

In the fourth embodiment, the stopper provided on the hydraulic cylinder body 145 is made detachable, cylinder operation without limiting the stroke is performed without using the stopper, or the stopper is replaced to limit the range of the piston movement. And the position can be changed and adjusted.

[0026]

【The invention's effect】

(1) A multi-stage boom device according to the present invention is a multi-stage boom device which connects a plurality of booms for pipe transporting a slurry through a joint and incorporates a hydraulic cylinder into the joint to bend between the booms. Two hydraulic pistons are accommodated in a cylinder and partitioned between both pistons to form two hydraulic cylinders. One hydraulic cylinder is a boom bending hydraulic cylinder for controlling the posture of the boom, and the other hydraulic cylinder is a hydraulic cylinder for bending the boom. The following effects are obtained by using a boom vibration control hydraulic cylinder that suppresses vibration of the boom as the cylinder.

Since one hydraulic cylinder can be provided with a plurality of properties, it is extremely easy to use one hydraulic cylinder for a plurality of purposes. In addition, the functions of each part are independent, and can perform multiple functions at the same time. The hydraulic system for the boom bending hydraulic cylinder and the boom vibration control hydraulic cylinder can be completely different from each other, and malfunction due to contamination of the solenoid valve in the hydraulic system by dust can be prevented.

Further, by minimizing the stroke length of the hydraulic piston for damping the boom, the fail-safe property at the time of malfunction of the control system can be easily secured. Also, the hydraulic cylinder for bending the boom and the hydraulic cylinder for damping the boom do not necessarily have to have the same processing accuracy, and each may be processed with the required processing accuracy, so that excessive quality can be prevented. In addition, it is generally easier to produce moderately small and short items with high accuracy than large and long items.
Speaking of hydraulic cylinders, it is easier to machine only a short stroke range with high accuracy than to machine an entire long stroke with high accuracy. This is easier than required conventional devices.

(2) The multi-stage boom device according to the present invention comprises:
In a multi-stage boom device in which a plurality of booms for pipe transporting a slurry are connected via joints and a hydraulic cylinder is incorporated in the joints to bend between the booms, a hydraulic cylinder for boom damping is provided continuously with the hydraulic cylinders. And the following effect is provided by providing the boom damping hydraulic cylinder with a stopper for limiting the movement of the piston to a certain range.

The function of the hydraulic oil as a spring element or a damper element can be positively utilized without reducing the oil volume of the system closed by the cylinder control valve and the cylinder. In addition, a cylinder stroke length at the time of cylinder malfunction is short, and a highly-safe vibration damping device can be realized. Further, in the form of the fourth embodiment, the stopper is detachable and the stroke length is adjustable, so that, for example, a cylinder that requires a long stroke, which is used for bending a slurry transport boom, etc., and which is used for vibration suppression, Short stroke desired cylinders (cylinders requiring a large oil volume in a closed system as described above) can be shared. That is, the boom damping cylinder can be used as a boom bending cylinder.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of a hydraulic cylinder used in a multistage boom device of the present invention.

FIG. 2 is a configuration diagram of a second embodiment.

FIG. 3 is a configuration diagram of a third embodiment.

FIG. 4 is a configuration diagram of a fourth embodiment.

FIG. 5 is an overall perspective view of a conventional concrete pump truck.

FIG. 6 is an enlarged view of a concrete pump part of FIG.

7 is a system diagram of a hydraulic cylinder for bending and damping a boom provided on a joint 6 of FIG. 5;

FIG. 8 is a hydraulic system diagram of FIG. 7;

9 is a system diagram of a hydraulic cylinder for vibration suppression of a type different from that of FIG. 7 provided in the joint portion 6 of FIG. 5;

FIG. 10 is a hydraulic system diagram of FIG. 9;

[Explanation of symbols]

 9 Hydraulic cylinder 42 Boom bending hydraulic system 43 Boom vibration control hydraulic system 47 Boom bending hydraulic cylinder 48 Boom vibration control hydraulic cylinder

Claims (2)

(57) [Claims] 1. A multi-stage boom device in which a plurality of booms for pipe transporting a slurry are connected via joints, and a hydraulic cylinder is incorporated in the joints to bend between the booms. A piston is accommodated and partitioned between both pistons to form two hydraulic cylinders. One hydraulic cylinder is a boom bending hydraulic cylinder for controlling the posture of the boom, and the other hydraulic cylinder is a vibration of the boom. A multi-stage boom device comprising a boom vibration control hydraulic cylinder for suppressing vibration. 2. A multi-stage boom apparatus in which a plurality of booms for pipe transporting a slurry are connected via joints and a hydraulic cylinder is incorporated in the joints to bend between the booms. A multi-stage boom device comprising: a hydraulic cylinder for vibration suppression; and a stopper for limiting the movement of a piston to a predetermined range in the hydraulic cylinder for boom vibration control.