JPH0571249U - Hydraulic excavator controls - Google Patents

Abstract

(57) [Abstract] [Purpose] To simplify and miniaturize the structure of the operation pattern switching valve, reduce the installation space, and allow easy installation on a small hydraulic excavator. [Structure] A rotor which is provided in the casing 61 of the operation pattern switching valve 60 with input ports R1 to R8 which are individually connected to the pilot ports of the pilot valves 31 to 38 and which is rotatably inserted into the casing 61. The shaft end face of 62 is provided with output ports C1 to C8 which are individually connected to the pilot ports of the working machine control valves 25 to 28. Inside the rotor 62, a plurality of passages consisting of holes in the axial direction and holes in the radial direction are provided, and by selecting each position by the rotation of the rotor 61, the input ports R1 to R8 and the output ports C1 to C8 are connected. The connection relationship is changed and the operation pattern is switched to four types.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a control device for operating a plurality of control valves for controlling the operations of a boom cylinder, an arm cylinder, a bucket cylinder and a swing motor of a hydraulic excavator.

[0002]

[Prior Art]

 The hydraulic excavator is generally constructed as shown in FIG. That is, in FIG. 6, 1 is a lower traveling structure, 2 is an upper revolving structure, 3 is a boom, 4 is an arm, 5 is a bucket, and these are left and right traveling motors (not shown), a revolving motor 6, and a boom cylinder. 7, the arm cylinder 8 and the bucket cylinder 9 operate. In order to operate the motors 6 and the cylinders 7, 8 and 9 described above, left and right traveling operation levers 11 and 12 and left and right working machine operation levers 13 and 14 are provided in the cab 10. There is.

By the way, although hydraulic excavators of this type are manufactured by several companies, their operating patterns, that is, the operating directions of the left and right operating machine operating levers 13 and 14, and the cylinders 7 and 7 operated by the operating patterns are described. Correspondence relations with Nos. 8 and 9 and the turning motor 6 are different for each manufacturer. Therefore, for example, when an operator who is accustomed to the operation pattern of company X operates according to the operation pattern of another company, the operation cannot be performed smoothly due to inexperience and the work efficiency is lowered. It may move in a direction that is not possible.

Incidentally, in hydraulic excavators, there are four typical operation patterns that are currently widely used. For this reason, there is a demand for a machine capable of arbitrarily selecting several operation patterns (typically four) with a simple switching operation.

Therefore, the following is conventionally known as a means for changing the operation pattern. B. Pilot line switching system-No. 1, (using an 8-port 2-position switching valve with a slide spool), this system is a pilot operated system as shown in, for example, Japanese Utility Model Publication No. 59-76669. 8 ports 2 equipped with slide spools between 2 pilot valves and 4 pilot ports of 2 pilot type control valves that control the operation of 2 actuators A position switching valve is provided, and the slide spool of this switching valve is made to slide in two positions in the axial direction to change the operation pattern by converting the connection relationship between each pilot valve and the pilot port of the control valve. To do.

(B) Pilot line switching system-No. 2, (using a plurality of electromagnetic switching valves), this system is pilot operated, as disclosed in Japanese Patent Laid-Open No. 60-168904. For multiple machines, multiple solenoid operated directional control valves (six solenoid valves) between multiple pilot valves and pilot ports of multiple pilot type control valves that control the operation of multiple actuators. Position switching valve), and by switching a plurality of these electromagnetic switching valves in a predetermined combination, the connection relationship between each pilot valve and the pilot port of the control valve is converted to change the operation pattern. is there .

C. Pilot line switching system-No. 3, this system is intended for pilot-operated machines, as shown in, for example, Japanese Utility Model Publication No. 2-22482, for each work installed on a hydraulic excavator. Each pilot type control valve for controlling the operation of the machine actuator, each pilot valve corresponding to the pilot port of each control valve, a plurality of operation levers for operating these pilot valves, and each of the above control valves It is equipped with a pilot port and one operation pattern switching valve that connects each pilot valve. The above operation pattern switching valve has a rotary pool that is rotatably displaced in a plurality of positions within a predetermined angle range in a casing. A plurality of input ports are connected to each pilot valve on the circumferential surface of the casing in the axial and circumferential directions. The rotary ports are provided at predetermined intervals and are out of phase with each other, and a plurality of output ports that are individually connected to the pilot ports are provided so as to be radially opposed to the inlet ports. The spool is provided with a plurality of passages that connect a plurality of radial holes and a plurality of axial holes so as to change the connection relationship between each input port and each output port for each position. There is. Therefore, the rotary pool of the operation pattern switching valve is rotationally displaced by a predetermined angle to switch to the desired position, and the connection relationship between each input port and each output port is converted into the connection relationship corresponding to multiple operation patterns. be able to.

[0008]

[Problems to be solved by the device]

 The above conventional technique has the following problems. The first problem is that in the switching valve system of b) above, the switching of pilot lines is performed, but the connection relationship between the two pilot valves to the two control valves for actuators is changed in the middle of the pilot lines. Since it is only converted, this a can be changed to only two operation patterns. In addition, in the above-mentioned a, if it is attempted to operate four actuators with four operation patterns by one switching valve, a 16-port 4-position switching valve is required. If the switching valve is a slide spool type in the axial direction, the spool becomes longer as the number of ports and the number of positions increase, and the entire switching valve becomes large, making it difficult to manufacture and installing it. It cannot be put to practical use due to space and operation restrictions.

As a second problem, in the above electromagnetic switching valve system, the number of operation patterns can be increased by increasing the number of electromagnetic switching valves, but conversely, to increase the number of operation patterns. The number of solenoid operated directional control valves must be increased, the number of solenoid operated directional control valves, the number of pipes and connecting parts are increased, the circuit configuration is complicated, the manufacturing is complicated, and the cost is high. Moreover, it is necessary to switch a plurality of electromagnetic switching valves in order to change the operation pattern, the switching operation is troublesome, and an unexpected working machine may be operated due to an incorrect switching combination, and Failures tend to occur and maintenance becomes very complicated. In addition, a large space is required for the installation of many electromagnetic switching valves. For this reason, the changeable range of the operation pattern in the above-mentioned B is at most three, and therefore this method cannot sufficiently satisfy the above-mentioned demand.

Next, as a third problem, in the switching valve system of C, pilot pressure is introduced from a plurality of input ports provided on the peripheral surface of the casing, and the pilot pressure is passed through a passage formed in the rotary spool. Since the output is made again from the multiple output ports provided on the peripheral surface of the casing through the holes, the axial and radial crossing relationship of the passage holes formed in the rotary pool becomes complicated, and the holes are complicated. Bright processing cost is high, and the outer shape of the operation pattern switching valve is considerably large. Moreover, since the pipes connected to the input port and the output port are connected in the radial direction with respect to the axis of the operation pattern switching valve and are piped all around, a considerably large space is required. For the above reasons, the operation pattern switching valve of C can be mounted on medium and large hydraulic excavators, but cannot be mounted on small hydraulic excavators.

The present invention has been made in view of the above circumstances, and is a small-sized control device that can arbitrarily select several operation patterns by a simple switching operation in one machine. It is an object of the present invention to provide a control device equipped with an operation pattern switching valve capable of changing a general operation pattern.

[0012]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the present invention, each pilot type control valve for controlling the operation of each actuator for a work machine such as a boom cylinder, an arm cylinder, a bucket cylinder and a swing motor in a hydraulic excavator, and each of these control valves are controlled. Each pilot valve corresponding to the pilot port of the valve, a plurality of operation levers that operate these pilot valves, and one operation pattern switching valve that connects the pilot port of each control valve and each pilot valve The operation pattern switching valve is configured by a rotor rotatably inserted in a plurality of predetermined positions in a casing, and is individually connected to the pilot port of each pilot valve or each control valve on the peripheral surface of the casing. Ports are provided in the axial and circumferential directions, and the rotor has a pilot port for each control valve or each port on the shaft end face. Ports that are individually connected to the ilot valve are provided, and a plurality of passages that communicate with the ports of the casing through the axial hole and the radial hole are provided so as to change the connection relationship for each position. ..

[0013]

【Example】

 FIG. 1 is a hydraulic circuit diagram showing an embodiment of the present invention. In FIG. 1, the same components as those in FIG. 6 are designated by the same reference numerals. Reference numeral 20 is a tank, 21 and 22 are hydraulic pumps, 23 and 24 are left and right traveling control valves, and the respective traveling control valves 23 and 24 are the left and right operation levers 11 provided in the operator's cab 10 (see FIG. 6). , 12 to control the operation of left and right traveling motors (not shown). Reference numeral 25 is a boom control valve, 26 is an arm control valve, 27 is a bucket control valve, 28 is a swing control valve, and pilot type directional control valves are used for these working machine control valves 25 to 28. , Pilot pressure from pilot valves 31, 32, 33, 34, 35, 36, 37, 38 is input to pilot ports 25a, 25b, 26a, 26b, 27a, 27b, 28a, 28b provided at both ends thereof. Then, the control valves 25 to 28 are switched to control the operations of the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9 and the swing motor 6, respectively.

Each of the pilot valves 31 to 38 is a variable pressure reducing valve that outputs a pilot pressure according to the operation of the left and right work machine operating levers 13 and 14 provided in the operator's cab 10 (see FIG. 6). , The levers 13 and 14 are arranged so as to correspond to the front-back and left-right operation directions. That is, the pilot valves 31, 32 and 33, 34 are operated by operating the left and right levers 13 in the front-rear directions a, b and the left-right directions c, d, and the right-side lever 14 in the front-rear directions e, f and the left-right directions g, h. By operation, the pilot valves 35, 36 and 37, 38 are operated.

The operation pattern switching valve 60 is for changing the operation pattern by converting the connection relationship between the pilot valves 31 to 38 and the pilot ports at both ends of the control valves 25 to 28. As shown in FIGS. 2 to 5, the rotary type is used. However, in FIG. 1, a slide type is shown in order to make the above-mentioned connection relationship easy to understand. Reference numeral 39 is a brake cylinder for the turning parking brake, and 40 and 41 are shuttle valves provided inside the operation pattern switching valve 60 for selecting pilot pressures.

Next, a specific structure of the operation pattern switching valve 60 will be described with reference to FIGS. FIG. 2 is a front view showing an embodiment of the operation pattern switching valve 60 used in the present invention. In FIG. 2, 61 is a casing of the operation pattern switching valve 60, 62 is a rotor, 63 is a switching lever that is integrally fixed to the rotor 62, and 64 is the switching of the rotor 62 to the respective positions A to D. When the rotor 62 is locked with respect to the casing 61, a detent device 65 is formed on the outer peripheral surface of the casing 61 for the detent device 64, and reference numerals R1 to R8 are formed on the outer peripheral surface of the casing 61. A plurality of input ports are connected to the pilot valves 33, 34, 32, 37, 31, 38, 36 and 37, respectively.

FIG. 3 is a side view seen from I in FIG. In FIG. 3, A, B, C and D indicate switching positions of the switching lever 63. FIG. 4 is a side view seen from II in FIG. FIG. 5 is a sectional view taken along line III-III in FIG.

In FIG. 5, reference numeral 66 is a pilot pressure selection valve fitted in the rotor 62 and provided with a high pressure selection circuit for the shuttle valves 40 and 41, and 67 is an output port of the selected pilot pressure. When performing the swinging operation of the upper swing body 2 (see FIG. 6) of the hydraulic excavator and the pulling operation of the arm 4, the pilot pressure for swinging or arm pulling is selected by the shuttle valves 40 and 41 described above, By outputting the pilot pressure signal from the output port 67 to the brake cylinder 39 for the turning parking brake (see FIG. 1), the turning parking brake is released.

That is, as shown in FIG. 1, when the operation pattern switching valve 60 is switched to the position A and the operation lever 13 is operated in the c direction or the d direction (turning operation), it is led out from the pilot valve 33 or 34. The pilot pressure is input to the input port R7 or R8 of the operation pattern switching valve 60. A part of the pilot pressure is selected by the shuttle valves 40 and 41 and acts on the brake cylinder 39. Therefore, since the turning parking brake is released, the upper revolving structure can be turned without any hindrance.

Further, the hydraulic excavator may push the side surface of the bucket against an inclined wall surface to excavate the wall surface by an arm pulling operation, or perform an oblique pulling and leveling work of the arm. Therefore, if the swing parking brake is not released when the arm pulling operation is performed in the above work, the swing parking brake may be damaged. Therefore, when the operation lever 13 in FIG. 1 is operated in the b direction (arm pulling operation), the pilot pressure output from the pilot valve 32 is input to the input port R6 of the operation pattern switching valve 60. A part of the pilot pressure acts on the brake cylinder 39 via the shuttle valves 40 and 41. As a result, the swing parking brake is released, and thus the arm excavation operation can perform the wall excavation and the oblique pulling and leveling work without any trouble.

The shuttle valves 40 and 41 are built in the pilot pressure selection valve 66 fitted inside the rotor 62, and when the operation pattern switching valve 60 is switched to each of the positions B, C and D, whichever position is selected. Even in such a case, during the turning operation and the arm pulling operation, a part of the pilot pressure acts on the brake cylinder 39 via the shuttle valve to release the turning parking brake.

Next, the configuration of the control device of the present invention will be described with reference to FIGS. In the control device of the present invention, the pilot type control valves 25, 26, 27, 28 for controlling the operation of the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the swing motor 6 for the working machine actuator in the hydraulic excavator. And pilot valves 36, 35, 32, 31, 38, 37, 33, 34 corresponding to the pilot ports 25a, 25b, 26a, 26b, 27a, 27b, 28a, 28b of these respective control valves, and these pilots It is provided with a plurality of operation levers 13 and 14 for operating the valves, and one operation pattern switching valve 60 for connecting the pilot port of each control valve and each pilot valve.

The operation pattern switching valve 60 is configured such that a rotor 62 is rotatably inserted into a casing 61 at a plurality of predetermined positions (four positions A, B, C, and D positions). Ports (input ports) R1 to R8 that are individually connected to the pilot ports of each pilot valve are provided on the surface (outer peripheral surface portion).

On the other hand, the rotor 62 has a port (output port) individually connected to the pilot ports 25a, 25b, 26a, 26b, 27a, 27b, 28a, 28b of the control valves 25, 26, 27, 28 on the shaft end face. ) C1 to C8 are provided, and a plurality of passages consisting of axial holes and radial holes are provided inside the rotor. In this case, the axial hole is communicated with each of the ports C1 to C8 individually, and one or a plurality of radial holes are communicated with the axial hole. By selectively communicating any one of the ports R1 to R8 of the casing 61, the connection relationship between the ports C1 to C8 and the ports R1 to R8 for each position (A, B, C, D). Is configured to transform. In addition, if necessary, in order to prevent the connection relationship between the specific input port and the specific output port from changing even if the position changes, the outer peripheral surface of the rotor or the inner peripheral surface of the casing 61 has a predetermined angle range. Grooves are provided.

In the above embodiment, ports R 1 to R 8 that are individually connected to the pilot valves 31 to 38 are provided on the circumferential surface of the casing 61, and the control valve 25, 26, 27, 28 is provided on the shaft end surface of the rotor 62. Ports C1 to C8 that are individually connected to the respective pilot ports are provided, but ports that are connected to the pilot ports of the respective control valves 25, 26, 27 and 28 are provided on the peripheral surface of the casing, and the ports of the rotor are also provided. The shaft end face may be provided with a port for connecting to each pilot valve individually.

Next, the operation of the control device of the present invention will be described. When the left operation lever 13 is operated in the front arrow a direction while the operation pattern switching valve 60 is held at the position A shown in FIG. 1, the pilot pressure corresponding to the lever operation amount is generated from the pilot valve 31 to the pilot pipe line. 42 → The input port R5 of the operation pattern switching valve 60 → The output port C5 → The pilot line 43 → The pilot port 26b, the arm control valve 26 is switched to the lower position in the drawing, and the oil discharged from the hydraulic pump 22 is transferred to the arm cylinder. 8 is guided to the oil chamber on the rod side, the cylinder 8 is contracted, and the arm pushing operation of rotating the arm 4 in FIG. 6 in the clockwise direction is performed. If the operation lever 13 is operated in the direction of the rearward arrow b, the arm pulling work for rotating the arm 4 counterclockwise is performed.

When the operation lever 13 is operated in the leftward arrow c direction, pilot pressure corresponding to the lever operation amount is applied from the pilot valve 33 to the pilot line 44 → the input port R7 of the operation pattern switching valve 60 → the output port C7 → The pilot line 45 is guided to the pilot port 28a, the turning control valve 28 is switched to the position in the drawing, the discharge oil of the hydraulic pump 22 is guided to the turning motor 6, and the motor 6 is turned to the left. The revolving work in which the upper revolving structure 2 in FIG. 6 revolves to the left is performed. If the operation lever 13 is operated in the direction of the arrow d to the right, the revolving work in which the upper revolving structure 2 revolves in the right direction is performed.

On the other hand, when the right operation lever 14 is operated in the front arrow e direction at the position A, the pilot pressure corresponding to the lever operation amount is changed from the pilot valve 35 to the pilot pipe line 46 → the operation pattern switching valve 60. Input port R1 → output port C1 → pilot line 47 → pilot port 25b, the boom control valve 25 is switched to the lower position in the drawing, and the oil discharged from the hydraulic pump 21 is in the oil chamber on the rod side of the boom cylinder 7. Then, the cylinder 7 is contracted and the boom 3 shown in FIG. 6 is rotated counterclockwise to perform boom lowering work. If the operation lever 14 is operated in the direction of the rear arrow f, the boom 3 is rotated clockwise to perform the boom raising work.

When the operation lever 14 is operated in the direction of the left arrow g, pilot pressure corresponding to the lever operation amount is applied from the pilot valve 37 to the pilot line 48 → the input port R4 → output port C4 → of the operation pattern switching valve 60. Pilot line 49 → Pilot port 27b is introduced, the bucket control valve 27 is switched to the lower position in the drawing, and the oil discharged from the hydraulic pump 21 is introduced into the head side oil chamber of the bucket cylinder 9 to move the same. The excavation work is performed in which the bucket 5 is extended and the bucket 5 in FIG. 6 rotates counterclockwise. If the operating lever 14 is operated in the direction of the arrow h to the right, the discharging operation in which the bucket 5 rotates clockwise is performed. Thus, a predetermined work is performed according to the operating directions ah of the operating levers 13 and 14.

Next, when the operation pattern switching valve 60 is switched to each position B, C, D, the connection relationship between each input port R1 to R8 and each output port C1 to C8 is as shown in Table 1 below. To be converted.

[0031]

[Table 1]

With the conversion shown in Table 1 above, the connection relationship between each pilot valve 31 to 38 and each pilot port of each control valve 25 to 28 is converted, the operation pattern is converted, and the operation lever 13, The relationship between the operation directions a to h of 14 and the work content is changed. Table 2 below shows the lever operation directions a to h at the respective positions A to D, the pilot valves 31 to 38, the input ports R1 to R8 of the operation pattern switching valve 60, the output ports C1 to C8, and the respective controls. It is a table which shows the relationship between each pilot port 25a, 25b, 26a, 26b, 27a, 27b, 28a, 28b of valves 25-28, and the work content.

[0033]

[Table 2]

By switching the operation pattern switching valve 60 as shown in Table 2, four typical operation patterns of the hydraulic shovels of each company can be selected. Therefore, by operating the operation levers 13 and 14 in the a to h directions with the operator switching the operation pattern switching valve 60 to the positions A to D corresponding to the desired operation pattern, the above operation is performed. Work according to the pattern is performed.

[0035]

[Effect of the device]

 As described above, the present invention uses a rotary type operation pattern switching valve, and rotationally displaces the rotor within a predetermined angle range to switch to a plurality of positions, so that one machine can operate several operation patterns arbitrarily. However, as a first effect, the structure of the operation pattern switching valve is improved so that the input ports communicating with each pilot valve are collectively provided on the peripheral surface of the casing or the shaft end surface of the rotor. Since the pilot pressure output ports from the pilot valves are provided together on the rotor shaft end surface or casing peripheral surface, pilot pressure is introduced, for example, from multiple input ports provided on the casing peripheral surface. , The pilot pressure is passed through radial and axial passage holes formed in the rotor, and multiple output ports are formed on the shaft end face of the rotor. More comprehensive output is possible, especially the axial and radial crossing and communication of the passage holes formed in the rotor during manufacture can be simplified, the drilling cost can be reduced, and the operation pattern switching valve The outer peripheral shape of can be made very small. However, since the pipes connected to the ports on the shaft end surface of the rotor are connected in the axial direction and the pipes can be put together in one direction, space can be saved. Further, since the input port and the output port are formed on the separate surface portions, the assembling work can be easily carried out without causing the connection mistake of the hydraulic piping.

Next, as a second effect, since it is possible to arbitrarily change to several operation patterns only by using one operation pattern switching valve, as compared with the above-mentioned one using the electromagnetic switching valve of the prior art b. In addition, the number of switching valves installed to change the operation pattern and the number of piping connections can be significantly reduced, the circuit configuration can be simplified, and it can be easily manufactured, resulting in a significant cost reduction. As described above, in the control device of the present invention, the operation pattern switching valve is made small, so that it is possible to equip a small hydraulic excavator and improve the effective use of the space inside the hydraulic shovel. ..

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram showing an embodiment of the present invention.

FIG. 2 is a front view showing an embodiment of an operation pattern switching valve used in the present invention.

FIG. 3 is a side view seen from I in FIG.

FIG. 4 is a side view seen from II in FIG.

5 is a sectional view taken along the line III-III in FIG.

FIG. 6 is a side view of the hydraulic excavator.

[Explanation of symbols]

 6 Swing Motor 7 Boom Cylinder 8 Arm Cylinder 9 Bucket Cylinder 13, 14 Working Machine Control Lever 21, 22 Hydraulic Pump 25 Boom Control Valve 26 Arm Control Valve 27 Bucket Control Valve 28 Swing Control Valve 31-38 Pilot Valve 60 Operation pattern switching valve 61 Casing 62 Rotor R1 to R8 input port C1 to C8 output port

Claims (1)

[Scope of utility model registration request] 1. A boom cylinder in a hydraulic excavator,
Each pilot type control valve for controlling the operation of the actuator for each working machine such as the arm cylinder, the bucket cylinder and the swing motor, each pilot valve corresponding to the pilot port of each of these control valves, and the plurality of pilot valves for operating these pilot valves An operation lever and one operation pattern switching valve connecting the pilot port of each control valve and each pilot valve are provided, and the operation pattern switching valve has a rotor rotatable in a casing at a plurality of predetermined positions. And a port individually connected to the pilot port of each pilot valve or each control valve is provided on the circumferential surface of the casing in the axial direction and the circumferential direction, and the rotor has a shaft end surface of each control valve. Pilot ports or ports that are individually connected to pilot valves are provided, and the axial and radial holes are used to Hydraulic excavator control apparatus in which a plurality of passage for bets and the communication is characterized in that provided in the arrangement for converting the connection relationship for each position.