JP2551539B2 - Multiple vibration suppression circuit selection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic vibration suppression circuit in which a base end portion of a working device provided so as to project from a vehicle body is pivotally supported on the vehicle body so as to be vertically rotatable. When a non-cushioned wheel-type construction machine, in which hydraulic cylinders are provided to support it, travels on undulating road surfaces, vibration suppression with preset characteristics that are optimal for the load conditions of multiple work equipment The present invention relates to a device that suppresses vibration of a vehicle body by selectively connecting to a circuit.

2. Description of the Related Art In a wheel-type construction machine, a working device is pivotally supported at a front part of a vehicle body, and rarely at a rear part so as to project and pivot vertically, and a hydraulic cylinder that supports the working device with respect to the vehicle body is provided. It is provided between the two, and it is expanded and contracted to reliably handle the work target with the work device, or to maintain a predetermined work posture or running posture. On the other hand, the vehicle body has a driver seat, a control device, a work device, and
In most cases, it is a so-called non-buffer type vehicle in which a frame for mounting a power plant or the like is directly mounted.

In recent years, such a wheel-type construction machine has been dramatically improved in running performance, steering performance, and running stability, and combined with the diversification of work types, it can be used for short distances while the work object is loaded on the work equipment. To move or to carry out heavy work as a work tool, for example, by attaching a snow plow,
It is more economical and the demand tends to be stronger,
When this wheeled construction machine continues to run at a certain speed or above, the vehicle body causes vibrations in the front / rear and left / right, pitching, rolling, yawing, and other non-attenuating swings that cause the machine body and the vehicle to run. Not only a large dynamic load is exerted on the road surface, but also the rider feels uncomfortable and tired, causing a health hazard and eventually causing an erroneous operation.

The occurrence of this non-damping swing is basically strongly influenced by the position of the center of gravity of the vehicle as a whole, the wheel base, the proportion of the mass overhanging the wheel base and protruding outward, and the running conditions. In terms of practical use, it is a combination of the types, positions, and weights of work tools such as buckets and snow plows, the magnitude of the load due to the work object, the undulation degree of the road surface, and the traveling speed. Conventionally, as a method of suppressing this vibration, when vibration occurs during traveling under certain operating conditions, the traveling speed is changed (mainly switching to lower speed traveling) as a means for driving operation,
Alternatively, the machine is equipped with hydraulic means in advance, that is, the pressure oil pipeline on the load side of the hydraulic cylinder supporting the working device is branched and communicated with the pipeline of the vibration suppression circuit including the slow return valve and the accumulator. The method is taken.

Of these measures, the former measure leads to a decrease in work efficiency, and the latter is not limited to the accumulator capacity and the initial charged gas pressure, but the slow return valve restricts the vibration. The characteristics of the vibration absorption energy of the circuit are naturally different, and the vibration suppression circuit having only certain characteristics cannot obtain the characteristics suitable for each of the various operating load conditions as described above. It will be far from achieved.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention When a hydraulic means for suppressing vibration of a wheel-type construction machine is taken, a load is not applied to a work device, a work object is loaded, and a work tool other than an original work tool is used. Therefore, it is practically possible to run in different states such as when a special work tool with a different weight or center of gravity is attached, but the accumulator in the vibration suppression circuit suitable for each of those states has its capacity or initial The pressure of the enclosed gas varies, and it is not possible to deal with it with only one characteristic.

The present invention provides a device for selecting and connecting a load-side oil chamber of a hydraulic cylinder to a circuit that exerts the most suitable vibration suppressing effect by remote control for each load state of the working device as described above. To do.

Means for Solving the Problems In order to solve the above problems, the present invention has the following configuration. That is, an internal oil passage is normally provided in each of the branch pipe passages that branch into a plurality of branch passages that connect the load-side oil chamber of the hydraulic cylinder supporting the working device to the pipe passage connected to the hydraulic switching valve for operating the hydraulic cylinder. It is closed and connected to multiple independent vibration suppression circuits consisting of accumulators with different characteristics, slow return valves, etc. via an open / close valve that opens when a signal acts on the receiving part. A device for remote control means for selectively or simultaneously operating a plurality of devices is provided.

Action When traveling on an uneven road surface, the working device
In a certain load state, operate the remote control device to open the on-off valve provided in the branch line leading to the vibration suppression circuit equipped with an accumulator having the characteristics suitable for the load state at that time, and open another load. When the vehicle is in a state, a vehicle body that supports various types of load conditions by opening the opening / closing valves of specific or multiple branch pipelines leading to a vibration suppression circuit equipped with an accumulator having different characteristics suitable for the load state The vibration of can be dampened.

Embodiment An embodiment of the present invention will be described with reference to the drawings.

1 and 2 are external side views of a wheel-type tractor excavator as a typical example of a wheel-type construction machine. In FIG. 1, a bucket 5 is used as a work tool of a work device 3, and in FIG. The vehicle body 2 is the same in all cases, but the center of gravity position G of the working device 3 and the front of the work device 3 when the bucket 5 is attached, when the vehicle is empty, when the vehicle is loaded and when the snow plow is attached. Distance from the center of wheel 1
l ₁ , l ₂ , l ₃ and their weights are different.

In this wheel-type tractor shovel, a working device 3 is mounted on a front frame 2a of a vehicle body 2 which is mounted on a plurality of wheels 1 using rubber tires in a bufferless manner. The work device 3 includes a boom 4 whose base end is rotatably supported by a front frame 2a, and a bucket 5 or a snow plow 6 which is rotatably supported by the tip of the boom 4. A tool, a lift cylinder 8 provided between the front frame 2a and the boom 4, a dump cylinder 9 provided between the front frame 2a and the work tool via a link device, and the like.

FIG. 3 is a hydraulic system diagram of this wheel-type tractor shovel, but is also an electrical system diagram according to the present invention. In this figure, 10 is a tank, 11 is a main pump for operating a working device in a hydraulic power unit, 12 is a dump cylinder hydraulic switching valve, 13 is a lift cylinder hydraulic switching valve, and a dump cylinder hydraulic switching valve 12 is provided. Pipeline 14a, 14b
The head-side oil chamber 9a of the dump cylinder 9 and the rod-side oil chamber 9b are connected to each other, and the head-side oil chamber 8 of the lift cylinder 8 is connected to the lift cylinder hydraulic switching valve 13 via the pipe lines 15a and 15b.
a, the rod side oil chamber 8b is connected. Further, a branch pipe 16 is provided in the oil chamber on the side of the lift cylinder 8 on which the weight of the work device 3 is loaded, that is, a pipe 15a connected to the head-side oil chamber 8a. The internal oil passages are branched and normally closed by the biasing force of the springs (position A in the figure), and when the electric signal is input to the receiver C, the internal oil paths are opened (position B in the figure). Solenoid valve
17a, 17b, 17c are provided. 20a, 20b, 20c are slow return valves 18a, 18b, 18c and accumulators 19a, 19 consisting of throttle valves 31a, 31b, 31c and check valves 32a, 32b, 32c, respectively.
b, 19c is a vibration suppressing circuit, the vibration suppressing circuit 20a is an opening / closing valve 17a, the vibration suppressing circuit 20b is an opening / closing valve 17b,
Further, the vibration suppressing circuit 20c is connected to the on-off valve 17c by independent pipe lines.

The accumulators 19a, 19b, 19c constituting these vibration suppression circuits 20a, 20b, 20c are given different characteristics, for example, the initial filled gas pressure is 19a is the lowest, 19c is the highest, and , The capacity is 19c is the maximum, etc., and as a result, the vibration suppression circuit 20a,
The characteristics of 20b and 20c are also different. For example, when the bucket 5 is attached to the vibration suppression circuit 20a as the work device 3 and the vehicle is empty, the distance between the center of gravity G of the bucket 5 and the center of the front wheel 1 is set.
The characteristic that the most effective vibration energy absorption function is given to the state of l ₁ is provided, and the vibration suppressing circuit 20b provides the center of gravity position G when the work object is loaded in the bucket 5.
Is given a characteristic that most effectively absorbs vibration energy for a state where the distance l ₂ between the front and the center of the wheel 1 is
Further, instead of the bucket 5, a heavy snow plow 6 is attached to the vibration suppressing circuit 20c, and the most effective vibration is obtained when the distance between the center of gravity G of the snow plow 6 and the center of the front wheel 1 is l _3. The characteristics of energy absorption are given, and the throttling effect of the throttle valves 31a, 31b, 31c promotes the vibration suppression effect in each of the above-mentioned states, so that different combinations are calculated or calculated in advance. Sometimes.

Further, as the accumulators 19a, 19b, and 19c, normally, a Prada type accumulator is used, and various types such as a capacity, an initial filled gas pressure, and the number of use, depending on the vehicle body, the weight of the working device, the weight ratio, the magnitude of the load, the position of the center of gravity, etc. Used in combination. Then, the vibration suppression circuit 20a, 20b, 20c, between the head side oil chamber 8a and the lift cylinder hydraulic pressure switching valve 13,
It is connected by external piping including the pipelines 15a and 16. Therefore, the accumulators 19a, 19b, and 19c are installed at arbitrary positions on the frame 2a by a connecting pipe method with a range that does not hinder the rotation of the boom 4 and the extension / contraction operation of the lift cylinder 8 and a pipe piping method with a minimum piping resistance. do it.

In this hydraulic system diagram, 21 is a main relief valve, 22, 23, 24 are overload relief valves of circuits communicating with the pipelines 14a, 14b, 15a, respectively, and 25, 26, 27, 28 are cavitation check checks. It is a valve.

Further, there is provided a selector switch 7 which is arranged near the driver's seat and can be easily operated by the driver with one hand. When the operation knob of the selector switch 7 is at the d position, the selector switch 7 is opened and closed via the electric wire 30a. When the operation knob is in the e position, the receiving portion C of the valve 17a is connected to the reception portion C of the on-off valve 17b via the electric wire 30b, and when the operation knob is in the f position, the opening / closing valve 17c is connected to the receiving valve C via the electric wire 30c. The power source 29 is guided to the receiving section C, and when the operation knob is set to the g position, the power source 29 is cut off.

Next, the operation of the present invention having the above configuration will be described.

When excavating or loading with a wheel-type tractor shovel, the vehicle speed is extremely low or is in a stopped state, and is not affected by ups and downs of the road surface. The position of the selector switch 7 is g
Leave it in the position. Then, since the power source 29 is not input to the receiving portion C of the on-off valves 17a, 17b, 17c, the on-off valves 17a, 17b, 17c are all kept at the A position by the biasing force of the spring, and the internal oil passage is closed. Then, the head side oil chamber 8a of the lift cylinder 8 is connected to the lift cylinder hydraulic switching valve 1 by the pipe line 15a.
Since it is connected only to 3, the working device 3 is securely held in the vehicle body 2 and the excavating and loading operations can be accurately performed with the hydraulic circuit of the conventional standard wheel type tractor shovel.

Then, the movement is started to transport the excavated earth and sand. At this time, when the operation knob of the selector switch 7 is set to the e position, the power supply 29 is connected to the receiver C of the on-off valve 17b via the selector switch 7 and the electric wire 30b. As a result, only the on-off valve 17b is switched from the A position to the B position, and the branch pipeline 16 is connected to the pipeline communicating with the vibration suppressing circuit 20b. This vibration suppression circuit 20b
The characteristic of is set in advance by calculation and experiment so that the most suitable vibration energy absorption is performed when the work object is loaded on the bucket 5, so that the vehicle main body 2 can be driven even when traveling on an uneven road surface. The vibration becomes damped vibration and is suppressed.
Next, when the loading of the excavated earth and sand is completed and the vehicle returns to the original excavation point in the empty state, or when it is forwarded by itself, when the operation knob of the selector switch 7 is set to the d position, the branch pipe is operated by the same operation as described above. The passage 16 communicates with a vibration suppressing circuit 20a having characteristics most suitable for an empty state via the B position passage of the opening / closing valve 17a, and the work device 3 is supported by a lift cylinder 8 provided with the vibration suppressing circuit 20a. Vibration of the vehicle body 2 is suppressed.

Further, the vibration suppressing circuit 20c is given a most suitable characteristic as a work tool to be mounted on the work device 3 when the weight and the position of the center of gravity are different from those in the above state, as in the snow plow 6, for example. In such a case, by setting the operation knob of the selector switch 7 to the f position, the working device 3 causes the lift cylinder 8 provided with the vibration suppression circuit 20c.
Since the vehicle body is supported by, the vibration of the vehicle body is suppressed even when traveling on an uneven road surface when the snow plow 6 is attached.

FIG. 4 is a hydraulic system diagram of essential parts showing a second embodiment of the present invention. The second embodiment is different from the first embodiment in that the on-off valves 17a, 17b and 17c are replaced by hydraulic pilot type on-off valves 33.
a, 33b, 33c are provided, and the pressure oil selectively taken out by the selector valve 34 using the pressure oil of the branch pipeline 16 is guided to these receiving parts C through the respective pipelines as pilot pressure. There is. Therefore, in the first embodiment and the second embodiment,
Although the remote control means of the on-off valve are different, their operation and effect are the same.

Further, in the embodiment of FIGS. 3 and 4, it is a diagram when there are three kinds of changes in the weight and the position of the center of gravity of the working device, and three kinds of vibration suppression circuits suitable for each state are also provided. In addition to this, it goes without saying that if the type of load condition of the work device increases or decreases, it is possible to increase or decrease the vibration suppression circuit corresponding to each, but regarding the type of the on-off valve and the remote control means. However, the present invention is not limited to this embodiment, and the selection and operation means based on a combination of existing technologies may be used.

EFFECTS OF THE INVENTION The present invention provides a vibration suppressing circuit suitable for absorbing the vibration energy of the vehicle body, which is obtained in advance by calculation and experiment, for each type of work tool that is supposed to be mounted as a work device for a wheel-type construction machine. They are provided independently of each other, and are selectively operated by remote control according to the working state so that they are communicated with the load-side oil chamber of the hydraulic cylinder that supports the working device. It is easy to obtain vibration suppression corresponding to the presence or absence of a payload, and while riding, the riding comfort is always good, it is effective for reducing driver fatigue and maintaining health.
You can work safely and efficiently while reducing damage to the aircraft and road surface.

[Brief description of drawings]

FIG. 1 is an external side view of a wheel type tractor shovel when a bucket is mounted, and FIG. 2 is a snow removing plow mounted, and FIG. 3 is a wheel type tractor shovel showing the first embodiment of the present invention. FIG. 4 is an electric / hydraulic system diagram in FIG. 4, and FIG. 4 is a main part hydraulic system diagram showing a second embodiment of the present invention. 3 …… Working device 5 …… Bucket 6 …… Snow removing plow 7 …… Selector switch 17a, 17b, 17c …… Open / close valve 20a, 20b, 20c …… Vibration suppression circuit 33a, 33b, 33c …… Open / close valve 34 …… Selector valve

Claims (1)

(57) [Claims] 1. A wheel-type construction machine in which a base end portion of a work device is pivotally supported on a vehicle body, and a hydraulic cylinder supports the weight and work load of the work device, and a predetermined vertical rotation operation is performed. The hydraulic chamber on the load side of the hydraulic cylinder is connected to the pipeline that connects to the hydraulic switching valve for operation. A plurality of hydraulic vibration suppression circuits configured to communicate with the accumulator, an on-off valve that is provided in the middle of the plurality of branch pipelines and can independently open and close the internal oil passage, and select the on-off valve A plurality of vibration suppression circuit selection devices each comprising a remote operation means that can be operated or opened in combination or in combination.