JPH0589555U - Meandering prevention device for hydraulic self-propelled work machine - Google Patents

Abstract

(57) [Summary] [Objective] In a self-propelled work machine in which the oil supply paths of the left and right traveling motors are connected when the work machine is operating, the work machine is operated so that the vehicle does not meander when the work machine operates. To obtain a device with a simple structure that can detect as quickly and reliably as possible. [Composition] In a self-propelled work machine in which the work machine and the travel motor are divided into two groups that are driven by a common hydraulic power source, and the oil supply circuits of the left and right travel motors are connected only when the work machine is activated. , A spool valve is used as the flow path switching valve 24 for switching the direction of oil supply to the working machine, one side of the spool type valve body is connected to the operation lever 25, and the other side is engaged with the operation detection switch SW ₁ . It is designed to detect the operation of the work implement quickly without a response delay.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention is a hydraulic excavator equipped with working means driven by a plurality of hydraulic cylinders for working, and running means such as wheels and tracks driven by hydraulic motors for right and left for running. TECHNICAL FIELD The present invention relates to a self-propelled working machine, and more particularly, to a device for improving the drawback that the straightness of the working machine is impaired when the working means is operated during traveling.

[0002]

[Prior Art]

 Generally, in a hydraulic self-propelled work machine, the hydraulic cylinders and hydraulic motors provided in the plurality of working means and traveling means are divided into two groups for the purpose of simplifying the hydraulic circuit and reducing the pressure fluctuation in the oil passage. The driving hydraulic motors are also configured so that the left and right belong to different groups.

However, in such a configuration, when a specific operating means is operated while the self-propelled working machine is traveling, the hydraulic pressure of the group to which it belongs is reduced, so that the hydraulic motor belonging to that group is reduced. The speed of the machine may decrease and the straightness of the work machine may be impaired. Therefore, conventionally, when the working machine operates while traveling, the supply oil passages connected to the left and right hydraulic motors are accordingly communicated with each other so that the left and right wheels are driven at a constant speed. Is being done. That is, a short-circuit communication oil passage that is normally closed by an on-off valve is provided between the oil supply passages of the left and right hydraulic motors, and the on-off valve is opened in conjunction with the operation of one of the hydraulic cylinders. .. There, as means for detecting the operation of one of the hydraulic cylinders, A) a method of detecting a differential pressure between two groups, and B) a flow path switching provided in an oil path leading from each hydraulic power source to the hydraulic cylinder. The switching operation of the valve is electrically detected.

[0004]

[Problems to be solved by the device]

 The method A) has a simple structure of the device, but the response tends to be delayed. In addition, the method B) has excellent responsiveness, the mechanical structure is complicated, and especially the working machine is used outdoors, so it is necessary to ensure dustproofness and waterproofing.

[0005]

[Means for solving the problem]

 The present invention aims to solve the above-mentioned problems, to provide dust-proof and waterproof, and to provide a detection means that does not change the basic structure of the flow path switching valve consisting of a spool valve. A spool valve is used as a flow path switching valve for switching the oil passage that connects the hydraulic valve and the hydraulic operating means, and both ends of the spool valve are projected from the valve box to the outside, and the operation lever is connected to one projected end of the spool valve. However, it is characterized in that the other end is covered with a cover attached to the valve box, and an electric detection means for detecting the forward / backward movement of the spool valve is provided inside the cover.

[0006]

[Work]

 An actuating lever 25 is connected to one side of the flow path switching valve 24 formed of a spool valve as in the conventional case. The detection means SW1 is provided on the opposite side of the operating lever 25 so as not to significantly change the configuration of the conventional flow path switching valve 24. Further, the detecting means SW 1 directly detects the behavior of the spool valve forming the flow path switching valve 24 so that there is no detection delay. Further, in order to ensure dustproofness and waterproofness, the detection means SW1 is provided in sealed covers 42 and 43 attached to the valve box 45 of the flow path switching valve 24 to cover the end of the spool valve. There is.

[0007]

【Example】

 Hereinafter, the invention will be described with reference to illustrated embodiments. In the figure, 1 is a self-propelled working machine utilizing this invention, that is, a power shovel. This self-propelled working machine 1 is provided with crawler tracks 2 for traveling on the left and right sides of the machine body, and has a body frame 3 supported by the crawler tracks 2. Reference numeral 4 denotes a leveling blade whose base end is rotatably supported by the vehicle body frame 3, and is supported by a blade cylinder 4a, which is a hydraulic cylinder, so as to be able to move up and down. Reference numeral 5 denotes a swing frame supported on the upper portion of the vehicle body frame 3, which is composed of a main frame 5a assembled by welding steel plates, on which a seat 5b for an occupant and an operation platform 5c are arranged in the center of the upper surface thereof. A shovel mechanism 6 is provided at the front and an engine (not shown) housed in a hood 5d provided at the rear. Further, 5e is an awning roof for the driver. Although not shown in the figure, separate hydraulic motors 31 and 32 for driving the crawler belts 2 for traveling provided on the left and right sides are supported by the vehicle body frame 3.

As shown in FIG. 2, the excavator mechanism 6 is supported by a sub-frame 5f provided at the front end of the swing frame 5. That is, the boom support member 6a is rotatably supported by the bearing member 5h and the vertical support shaft 6b at the front end of the sub-frame 5f. As shown in FIG. 3, a swing cylinder 6c, which is a hydraulic cylinder, is interposed between the boom support member 6a and the main frame 5a, and is pivotally driven by the operation of the swing cylinder 6c.

A base end of the boom 7 and a boom cylinder 7a, which is a hydraulic cylinder for tilting the boom 7 mainly in the front-rear direction, are supported on the boom support member 6a. A bucket arm 8 is rotatably supported on the free end of the boom 7, and an arm cylinder 8a, which is a hydraulic cylinder for rotating the bucket arm 8, is also supported. Reference numeral 9 denotes a bucket supported on the free end of the bucket arm 8, which is rotationally driven by a bucket cylinder 9a which is also a hydraulic cylinder supported on the bucket arm 8.

A hydraulic circuit for operating the traveling work machine 1 is shown in FIG. In the figure, reference numeral 21 is a triple hydraulic pump driven by an engine, which sucks oil in an oil tank 22 and passes through three oil supply ports 23, 23 to the first group. The hydraulic fluid is supplied to the hydraulic operating means forming A, the second group B, and the third group C, that is, each hydraulic cylinder. That is, the PTO output coupler 33 for supplying pressure oil to the outside, the arm cylinder 8a, the swing motor 35 for rotating the swing frame 5 in an arbitrary direction, and the hydraulic motor motor 31 for driving the crawler belt 2 on the left side. Including.

Similarly, the second group B also includes a swing cylinder 6c, a bucket cylinder 9a, a boom cylinder 7a, and a hydraulic motor / motor 32 that drives the right crawler belt 2. The third group C includes a blade cylinder 4a and a second-speed traveling circuit 34 that supplementally supplies pressure oil to the left and right hydraulic motors 31 and 32 to increase the traveling speed. Reference numeral 24 is a group of flow path switching valves provided in an oil passage that connects the hydraulic pump 21 and each hydraulic cylinder, and is specifically a spool valve. Reference numeral 25 is an operating lever for manually switching the respective passage switching valves 24, and 26 is a return oil passage for returning the hydraulic oil from the respective hydraulic cylinders to the oil tank 22.

Here, the oil supply passages 23, 23 for supplying pressure oil to the hydraulic motors 31, 32 for driving the left and right crawler belts 2 are connected to the inlet ports of the passage switching valves 24, 24 by the communication oil passage 27. Are connected to each other. An on-off valve 28 connects or disconnects the communication oil passage 27. The opening / closing valve 28 is controlled to open / close via a pilot valve 29 which is electromagnetically operated.

FIG. 7 shows an electric circuit 40 for operating the pilot valve 29. That is, in the electric circuit 40, between the battery 41, which is a power source, and the solenoid 42 of the pilot valve 29, the four flow path switching valves 24 are operated by detecting the operation of the four connected in parallel. Three types of switches, a switch SW1 and traveling detection switches SW2 and SW3 provided on the left and right hydraulic motors 31 and 32 and closed during operation of the left and right crawler belts 2, are interleaved in series. When all the switches SW1, SW2, and SW3 are closed, the solenoid 42 is excited by the battery 41 to open the open / close valve 28. It is not always necessary to provide two traveling detection switches SW2 and SW3, and one of them can be omitted as shown in FIG.

Next, the mounting structure of the work implement switch represented by the four switches SW1 connected in parallel will be described. As shown in FIGS. 9 and 10, the operation detection switch SW1 of each working machine is formed by arranging a plurality of flow path switching valves 24 in parallel and assembling them by connecting a plurality of bolts. A shaft-shaped valve element 44 is slidably supported in a valve hole provided therein, and so-called so-called communication between the annular grooves formed in the valve hole is interrupted via a groove formed on the outer periphery of the valve element. It is a spool valve.

The flow path switching valve 24 in this embodiment is configured by protruding both ends of the valve element 44 from the valve box 45 to the outside in addition to the known structure of the spool valve. An operation lever 25 that is manually operated is connected to one end of the lever. Further, as shown in FIG. 11, an extension shaft 47 is screwed into the shaft hole at the other end of the valve element 44, and an outer circumferential grooved cam 48 formed on the extension shaft 47 and a contactor of a microswitch 49. Together form a detection means for detecting the operation of the valve element 44, that is, SW1 in FIG. In the micro switch 49, when the extension shaft 47 is retracted into the valve box, the contactor engages with the cam 48 having an outer circumferential groove as shown in the figure, and when the extension shaft 47 moves outward as shown by the phantom line, It is disengaged from the cam 48 having an outer peripheral groove. In this way, the microswitch 49 is turned on and off, and the signal is input to the electric circuit 40 described above.

Further, since the flow path switching valve 24 has one end and the other end of the shaft forming the valve body 44 of the spool valve projected outside the valve box, the operation detection switch SW1 and the operating lever 25 of each working machine are connected. Can be arranged on the opposite side of the valve box 45. Furthermore, since the movement of the valve element 44 is directly detected by the operation detection switch SW1 of each working machine, the operation of the working machine can be detected without delay.

It should be noted that the extension shaft 47 is not an essential requirement in the structure of the present invention, and may be mechanically formed integrally with a screw as in this embodiment, or may be formed integrally. Of course, it is okay. Here, the micro switch 49 is itself mounted in the sealed case 43, and is mounted on the cover 42, which covers the outside of the valve body mounted on the valve box 45, via the extension shaft 47, and Not only the end of the body 44 but also the micro switch 49 can be surely dust-proofed and waterproofed.

Next, the handling of the oil hose 60 connected to the hydraulic cylinder around the boom from the hydraulic pump 21 via the flow path switching valve 24 will be described. As shown in FIGS. 1 and 3, the oil hose 60 reaches the boom 7 from the flow path switching valve 24 supported by the sub-frame 5f via the vicinity of the boom support member 6a, and reaches a desired hydraulic cylinder along its longitudinal direction. Connected to. At this time, it is preferable to pass the oil hose 60 on the axis of the pivot shaft 61 that supports the base end of the boom 7 so that the oil hose 60 does not get in the way when the boom 7 is tilted. As a result, even if the boom 7 is undulated, it is possible to prevent the tensile force from acting, and the oil hose 60 only provides a simple bending action and improves durability. A hose clamp 62 is installed on the boom support member 6a to provide such a path to the oil hose 60.

The hose clamp 62 is installed on the boom support member 6 a so as to approach the base end of the boom 7. That is, the oil hose 60 is sandwiched between the buffer members 64, 64 made of rubber-like synthetic resin, and is fastened on the boom support member 6a by the bolt 67 via the seat plate 66. One end of the seat plate 66 is fixed to the fixing boss 58 of the supporting plate 59 of the adjacent boom 7 with a bolt 57 to prevent the bolt 67 from loosening together when the oil hose 60 is pulled. ing.

The hose clamp 62 is not limited to the example shown in FIG. 5, and for example, the one shown in FIGS. 13 and 14 can be used as a hose clamp that can also be used for several types of oil hoses having different thicknesses. That is, the radius of the hose support concave portion 68 provided in the buffer member 64 that supports the two oil hoses 60 is processed according to the outer diameter of the thickest oil hose used, and the oil hose thinner than that is processed. When supporting an oil hose, the difference between the radius of the hose supporting recess 68 and an oil hose having a diameter smaller than that is eliminated by one auxiliary pad 69 or by interposing several auxiliary pads 69 having different diameters.

[0021]

As described above, according to the present invention, the flow passage switching valve 24 for switching the oil passage 23 that connects the hydraulic pump and the hydraulic cylinder is a spool valve, and both ends of the valve element 44 are valve boxes 45. Since it is projected from the outside to the outside, one end thereof can be connected to the operation lever 25, and the other end can be made to cooperate with the microswitch 49 which is an electrical detection means. Therefore, the operation of the valve element 44 can be detected reliably and quickly. Further, since the detecting means 49 is attached to the inside of the covers 42 and 43 which cover the shaft end of the valve body, the valve body 44 and the micro switch 49 which is the detecting means can surely be dust-proofed and waterproof. It has a great effect.

[Brief description of drawings]

FIG. 1 is a side view of a mini shovel machine using the present invention.

FIG. 2 is an enlarged side view of the main part.

FIG. 3 is a plan view of FIG.

FIG. 4 is an arrow IV view of FIG.

FIG. 5 is a VV sectional view thereof.

FIG. 6 is a hydraulic circuit diagram.

FIG. 7 is an electric circuit diagram for opening and closing the communication passage 27.

FIG. 8 is an electric circuit diagram corresponding to FIG. 7 showing a modification thereof.

FIG. 9 is a plan view of a flow path switching valve 24 connected to each hydraulic cylinder.

FIG. 10 is a sectional view taken along the line XX.

FIG. 11 is an enlarged cross-sectional view of a main part showing a part of the device in an enlarged manner.

FIG. 12 is a sectional view taken along the line XII-XII.

13 is a cross-sectional view corresponding to FIG. 5 showing a modified example of the hose clamp.

FIG. 14 is a view showing another example of using the hose clamp.
It is a considerable sectional view.

[Explanation of symbols]

 24 ... Flow path switching valve 25 ... Operation lever 27 ... Communication passage 28 ... Open / close valve 49 ... Micro switch

Claims (1)

[Scope of utility model registration request] 1. A spool valve is used as a flow path switching valve for switching an oil passage connecting a hydraulic pump and a hydraulic operating means, and both ends of the spool valve are projected from a valve box to the outside, and the spool valve is projected. A hydraulic self-propelled working machine in which an operation lever is connected to one end, the other end is covered with a cover attached to a valve box, and an electric detection means for detecting the forward / backward movement of the spool valve is provided inside the cover. Meandering prevention device.