KR100188885B1 - Straight driving apparatus for heavy equipment - Google Patents

Abstract

Even if you operate the work device while driving a variety of construction machinery such as excavators, cranes, etc., it is possible to maintain the straightness of the driving.

According to a preferred embodiment, in a traveling straight device of heavy equipment provided with a traveling support circuit, the predetermined position of the traveling system flow path 21 immediately after passing through the traveling straight valve 10 and the predetermined working device flow path 23 are provided. A connecting flow path 25 for interconnecting positions and a check valve 27 installed in the connecting flow path 25 to allow only hydraulic oil flow from the work system flow path 23 to the traveling system flow path 21. It provides a straight traveling device of heavy equipment, characterized in that configured with.

As a result, a sudden drop in the running speed can be prevented even when the straight traveling device is operated due to the operation of the work device while the machine is running, and thus a significant improvement in workability can be expected.

Description

Straight line traveling device for heavy equipment

The present invention relates to a straight traveling device for heavy equipment, and more particularly, to an apparatus for maintaining the straightness of the driving even when operating the working device of the traveling various construction machines such as excavators, cranes and the like. In particular, the present invention relates to a straight traveling device for heavy equipment that prevents a sudden drop in the running speed when the straight traveling device is operated by branching a part of the flow rate supplied to the work system actuator from the straight traveling device.

In general, a traveling construction machine such as an excavator or a crane is configured such that the traveling system actuator (driving motor) and the working system actuator (boom cylinder, arm cylinder, bucket cylinder) are operated by the flow rate discharged by the same pump. It is.

That is, as shown in FIG. 1, the first hydraulic pump P1 and the second hydraulic pump P2 having the same capacity are installed to be driven by a single engine, and the first hydraulic pump P1 is driven rightward. It is responsible for supplying hydraulic oil to the motor (TR) and work device actuators (meaning boom cylinder, auxiliary device and bucket cylinder), and the second hydraulic pump (P2) is the left driving motor (TL) and work device actuator. (Swing motor, arm cylinder) is responsible for supplying the hydraulic fluid.

Reference numerals TR and TL are shown to indicate the right driving motor control valve and the left driving motor control valve in the drawings, but for convenience of description, it is indicated as the right driving motor and the left driving motor itself throughout the specification. In addition, the reference numerals BOOM, ACC, BKT, SW, ARM are shown to indicate the control valves of the working system actuators, respectively, in the drawings, but for convenience of description, this is indicated as the working system actuators throughout the present specification.

In the conventional equipment configured as described above, when the engine is started and the driving motors TR and TL are operated, the flow rate discharged from the first hydraulic pump P1 is supplied to the right driving motor TR through a predetermined flow path. The flow rate discharged from the second hydraulic pump P2 is supplied to the left driving motor TL through a predetermined flow path, and at this time, the capacity of the first and second hydraulic pumps P1 and P2 is the same. Could go straight.

However, when operating the at least one work device while the equipment is running straight as described above, for example, when operating the arm by supplying hydraulic oil to the arm cylinder (ARM), the second hydraulic pump (P2) The flow rate discharged from) was distributed to the left driving motor (TL) and the arm cylinder (ARM) through the parallel flow path. Therefore, since the flow rate supplied to the left driving motor TL is reduced compared to the right driving motor TR, the equipment does not maintain the straightness, there is a problem that is deflected to the left.

Therefore, even when the work device is operated while driving the equipment, a straight traveling device is absolutely necessary to prevent the unexpected deflection of the equipment and to maintain the straightness of the driving.

The straight traveling device is composed of a traveling straight valve 10 installed in the hydraulic circuit, and the first and second hydraulic pumps P1 and P2 are driven by the right driving motor TR and the left driving when the work device is not operated while driving. While independently supplying hydraulic oil to the motor TL, one of the first and second hydraulic pumps P1 and P2 (P1 in FIG. 1) is operated when the work device is operated. ) And the left driving motor (TL) were in charge of supplying the hydraulic fluid at the same time, the other hydraulic pump (P2) was designed to be responsible for the supply of the hydraulic fluid of the operated work device. As a result, the right and left running motors TR and TL are always supplied with the same flow rate regardless of whether the work device is operated, and the straight running function is realized.

However, in the conventional straight traveling apparatus as described above, when the straight traveling operation, the first hydraulic pump (P1) is responsible for supplying the hydraulic oil to the right and left running motors (TR, TL) at the same time, the second hydraulic pump (P2) In charge of the supply of hydraulic oil to the manipulated work tool actuator, there has been an inefficiency in terms of flow distribution.

That is, the equipment maintains the straightness of the running, but the running speed is rapidly reduced as the discharge flow rate of the first hydraulic pump (P1) is equally distributed to the right and left running motors (TR, TL). This problem has been a problem that the equipment running at a predetermined speed (for example, 40 KM / h) can only travel at a speed of 20 KM / h during the straight running operation according to the operation of the work device.

In addition, such a straight traveling device has been filed as a Korean Patent Publication No. 95-6161 (name: hydraulic device for heavy equipment capable of straight traveling).

That is, in the Patent Publication No. 95-6161, as shown in FIG. 2 of the drawings and as described in the claims, the main pumps 2 and 3 and the pilot pump 4 are connected to the engine 1, and the main The valves 13 and 15 for adjusting the driving motors 9 and 10 are connected in parallel to the center bypass passages 5 and 6 communicating with the supply side passages 24 and 25 of the pumps 2 and 3, respectively. Panel lines 30 and 32 branched to 24 and 25 are connected to the supply ports of the valves 13 and 15, and pilot valves 21 and 22 connected to the supply side flow path 20 of the pilot pump 4 are In the hydraulic circuit for heavy equipment connected to the driving motors (9,10) operation valves (11, 16) by pilot lines (28, 28 ') (39, 39'), the swing motor (7) and the work device (12). The selector valves 34 and 35 are installed in the operation valves 8 and 13, and the traveling straight pilot line 40 communicating with the selector valves 34 and 35 is connected to the pilot pump 4. Branch connection to a supply side flow path 20, and the pilot line 40 It is characterized by connecting the straight running valves 41 and 42 for joining the flow paths of the main pumps 2 and 3 to one end.

At this time, orifices 49 and 50 are installed in the straight traveling valves 41 and 42, and orifices 47 are installed in the back pressure pilot line 46 of the straight traveling valves 41 and 42.

However, the above-mentioned Patent Publication No. 95-6161 discloses a work device 12 when the work device 12 or 14 is operated simultaneously while traveling at a flow rate discharged from each of the hydraulic pumps 2 and 3 having the same capacity. Alternatively, as the flow rate discharged to 14) is supplied to the driving motor 7 or 10 to replenish, the driving straightness function is secured, thereby preventing the deflection. Has another problem that is abruptly slowed down.

Accordingly, an object of the present invention is to provide a straight traveling device for heavy equipment equipped with a traveling support circuit so that a sudden drop in the traveling speed can be prevented even when the straight traveling device is operated due to the operation of the work device while the equipment is running.

1 is a hydraulic circuit diagram of a heavy equipment equipped with a conventional straight traveling device.

2 is a hydraulic circuit diagram of heavy equipment equipped with a straight traveling device for heavy equipment according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

P1, P2: 1st and 2nd hydraulic pump T: Hydraulic tank

TR, TL: Control valve for right and left running motor

BOOM: Control valve of boom cylinder ACC: Control valve of auxiliary device

BKT: Bucket cylinder control valve SW: Swing motor control valve

ARM: Control cylinder of arm cylinder 10: Running straight valve

21: driving system flow path 23: working device flow path

25: connection passage 27: check valve

29: orifice

The object of the present invention described above is a predetermined position of the traveling system flow path 21 and the working system flow path 23 immediately after passing through the traveling straight valve 10 in the traveling straight apparatus of the heavy equipment provided with the traveling support circuit. A check valve installed between the connection flow path 25 and the connection flow path 25 for interconnecting a predetermined position of the check flow path, and permitting only the flow of hydraulic oil from the work system flow path 23 to the travel system flow path 21 ( 27) by providing a straight traveling device of heavy equipment characterized in that it is configured to.

According to the present invention configured as described above, even if the straight running device is operated by operating the work device while driving, some of the operating oil in the work system flow path can be supplemented and supplied to the travel system flow path through the above-described connection flow path of the equipment. The sudden drop of can be prevented.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are intended to assist in understanding the technical contents of the present invention, and thus the technical scope of the present invention is not limited.

In describing the embodiment of the present invention, the configuration and operation of the basic hydraulic circuit of the heavy equipment has already been described in detail with reference to FIG. 1, and thus will not be redundantly described. The same reference numerals are used for the same reference numerals.

As shown in FIG. 2, the first hydraulic pump P1 and the second hydraulic pump P2 of the same flow rate are installed to be driven by a single engine, and the first hydraulic pump P1 is a right driving motor ( TR) and the working oil supply to the work system actuators (boom, auxiliary device, bucket), the second hydraulic pump (P2) to the left running motor (TL) and the work system actuators (swing, arms) It will be in charge of supplying hydraulic fluid.

The traveling straight valve 10 is installed in the hydraulic circuit, and the traveling straight valve 10 is configured such that the first and second hydraulic pumps P1 and P2 are driven to the right of the driving motor TR and when the work device is not operated while driving. While independently supplying hydraulic oil to the left traveling motor TL, when the work device is operated, either one of the first and second hydraulic pumps P1 and P2 is connected to the right traveling motor TR and It is in charge of supplying the hydraulic oil of the left running motor (TL), and the other one hydraulic pump (P2) to be responsible for supplying the hydraulic oil of the operated work device.

In this embodiment, immediately after passing through the above-described traveling straight valve 10, the connecting flow path 25 is provided so that the branched traveling system flow path 21 and the work device flow path 23 are interconnected. As the check valve 27 and the orifice 29 are installed in (25), a traveling support circuit is comprised.

According to the driving support circuit as described above, during the driving straight operation, a part of the discharge flow rate of the first hydraulic pump P1 is supplied to the operated work device actuator side, and the other part is connected to the orifice 29 of the connection passage 25 described above. It is connected to the traveling system flow path 21 via the check valve 27 and eventually joins the traveling motors TR and TL.

As described above, according to the preferred embodiment, since the sudden drop in the running speed can be prevented even when the straight traveling device is operated due to the operation of the work device while the equipment is running, a marked improvement in workability can be expected.

Claims (1)

A traveling linear device of a heavy equipment equipped with a traveling support circuit: a connection for connecting a predetermined position of the traveling system flow path 21 immediately after passing through the traveling straight valve 10 to a predetermined position of the work system flow path 23; A flow path 25; And a check valve 27 installed in the connection flow path 25 and configured to allow only a flow of the hydraulic oil from the work system flow path 23 to the travel system flow path 21. Traveling device.