JP2006183405A - Loader hydraulic circuit and loader hydraulic piping - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a loader hydraulic circuit and loader hydraulic piping provided with a selector valve which can mount an attachment with an actuator quickly and easily without repiping. <P>SOLUTION: The selector valve 41 includes first ports X, Y connectable to a direction switching valve, second ports C1, D1, C2, D2 connectable to a dump cylinder 10 and usually communicating with the first ports via a passage in the main body, third ports A, B connectable to the first actuator 64 of the attachment, and fourth ports E, F connectable to the second actuator 70 of the attachment. The selector valve 41 is arranged in the middle of the loader hydraulic piping from the direction switching valve of the loader connected to a pump to the dump cylinder of the loader. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a loader hydraulic circuit and a loader hydraulic pipe including a selector valve corresponding to an attachment with an actuator.

  For example, a loader is used for operations such as unloading and transporting grass, compost, and earth and sand in farm work. This loader is equipped with a lift arm that can be raised and lowered on a traveling vehicle such as a tractor, and an attachment such as a bucket or a fork that is a desired working machine is detachably attached to the tip of the lift arm.

  FIG. 12 shows an outline of this type of loader. In the figure, 1 is a tractor, 2 is a main frame attached to the front portion of the tractor 1, 3 is pivotally attached to the main frame 2 via a pivot 4, and is lifted up and down by a lift cylinder 5. An arm 8 is a bucket that is pivotally attached to the tip of the second arm portion 3 b of the lift arm 3 via a pivot 9, and discharges and scoops by a dump cylinder 10.

  When, for example, earth and sand are loaded onto a truck or the like with this loader, first, the lift arm 3 is laid down with the lift cylinder 5 to hold the bucket 8 at the lower end position. In this state, the bucket 8 is rotated upward, so that earth and sand are poured into the bucket 8, and then the lift arm 3 is lifted by the lift cylinder 5 to lift the bucket 8 to the rising end position. After moving to the standby position, the bucket 8 is rotated downward by the dump cylinder 10 to discharge the earth and sand poured into the bucket 8 and loaded onto a truck or the like.

  FIG. 13 shows the detailed structure around the lift arm excluding the bucket, and the hydraulic piping system for the lift cylinder 5 and the dump cylinder 10 is shown. That is, hydraulic pressure is selectively supplied from a hydraulic pump of a tractor (not shown) to two pipes P1 and P2 for a lift cylinder and two pipes P3 and P4 for a dump cylinder, respectively. 5 and 10 are extended or shortened. The hydraulic pump is connected to two directional control valves for lift and dump that are provided on the loader side, and by operation of these two directional control valves, two pipes P1, P2 for the lift cylinder and The hydraulic pressure is selectively supplied to the two pipes P3 and P4 for the dump cylinder, respectively.

 A T-shaped branch pipe is disposed in the middle of the lift cylinder pipes P1 and P2, and hydraulic pressure is evenly supplied to and discharged from the left and right lift cylinders 5 and 5. Further, the tip ends of the pipes P3 and P4 for the dump cylinder are extended to the connecting pipe 15 that connects between the arm tips, and are connected to the distribution block 17 that is fixed to the center of the connecting pipe 15 via the mounting plate 16. The As shown in detail in FIG. 14, the distribution block 17 includes a pair of first ports 18 and 18 connected to the load direction switching valve via pipes P3 and P4, and a dump cylinder via the pipes P5 and P6. 10 and 10 have a pair of left and right ports 19 and 19 connected to each other. A safety valve 21 for protecting the hydraulic circuit is attached to the upper and lower ports 20, 20, and the front ports 22, 22 are closed with banjo bolts 23, 23.

  By the way, in this type of loader, in addition to a predetermined attachment such as a bucket, the user may want to attach another attachment with an actuator. In such a case, conventionally, when there is one attachment actuator, the selector valve 30 is attached to the distribution block as shown in FIG. The selector valve 30 is attached to the connecting pipe 15 of the arm 3 via the attachment plate 16a. The loader side direction switching valve is connected to the two ports 31 and 31 on the side surface of the selector valve 30 via the pipes P3 and P4, and the other two ports 32 and 32 on the lower surface of the selector valve 30 are connected to the pipe. Hydraulic pressure is supplied to and discharged from the cylinder of the attachment via P7 and P8. Before mounting the attachment with the actuator, the two ports 18 and 18 of the distribution block 17 connected to the direction switching valve on the loader side are connected, and the banjo bolts 23 and 23 are connected to the two ports 33 and 33 on the upper surface of the selector valve 30. Use to connect. The two left and right ports 19 and 19 of the distribution block 17 are connected to the dump cylinder 10 as before. In addition, the safety valve 21 is attached to the two front and rear ports 20 of the distribution block 17 as before.

  The above is a case where there is one attachment actuator, but when there are two attachment actuators, a dedicated selector valve for two actuators is attached to the distribution block 17 and the piping is redone.

  As described above, when the attachment with an actuator is attached to the conventional distribution block 17, it is necessary to rework the piping significantly, and the work is very troublesome and the cost is increased, and the selector valve 30 also requires one attachment actuator. Because it is different for the two, it was not always convenient to use, such as having to prepare each. Further, since the distribution block and the selector valve are combined, the pressure loss of the hydraulic pressure increases, and there are problems such as heat generation and a reduction in operating speed.

  An object of this invention is to provide the loader hydraulic circuit and loader hydraulic piping which can mount | wear with the attachment with an actuator quickly and easily, without repeating piping.

  In order to achieve the above-described object, the loader hydraulic circuit according to the present invention is configured such that the direction switching is performed in the main body having a spool valve in the middle of the loader hydraulic piping from the direction switching valve of the loader connected to the pump to the dump cylinder of the loader. A first port connectable to a valve, a second port connectable to the dump cylinder and normally communicated with the first port via a passage in the main body, and an attachment mounted on the loader A third port connectable to the first actuator; and a fourth port connectable to the second actuator of the attachment attached to the loader; and the spool valve is connected to the first port on the main body. A first moving means that blocks communication with the second port and is movable to a first position that communicates the first port and the third port; and / or the sp And a second moving means that blocks the communication between the first port and the second port and that can be moved to a second position that connects the first port and the fourth port. A selector valve is provided (claim 1).

  The loader hydraulic piping according to the present invention includes a pair of left and right dump cylinders disposed in the loader, the selector valve disposed at a substantially intermediate position of the dump cylinder, and the left and right sides of the selector valve body. 2 ports are formed, hydraulic piping is linearly arranged from the second port to the left and right dump cylinders, and the third port and the fourth port are provided in a direction perpendicular to the second port. (Claim 2).

 According to the present invention configured as described above, when attaching an attachment with an actuator, it is only necessary to attach the first moving means and / or the second moving means to the selector valve and connect the piping for the actuator of the attachment. Therefore, it is not necessary to re-work the piping as in the conventional case, and the attachment with the actuator can be quickly and easily attached. Further, since the selector valve has a distribution block function, the pressure loss of the hydraulic pressure is reduced, and the problems of heat generation and a reduction in operating speed are solved.

 Further, as described above, since the selector valve has the conventional distribution block function, the design valve can be provided with a high degree of freedom in relation to the arrangement position of the selector valve, and the selector valve can be arranged at a substantially intermediate position between the pair of left and right dump cylinders. Yes, by forming the second port connected to the dump cylinder on the left and right sides of the selector valve body, hydraulic piping can be linearly arranged from the second port to the left and right dump cylinders, and the piping length is minimized. Pressure loss can be further reduced, and piping can be made easier by providing the third port and the fourth port in a direction orthogonal to the second port.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1-5 shows the case where the attachment which has one actuator is mounted | worn. Here, “one actuator” means a plurality of actuators that operate in the same manner. The pair of left and right actuators 64 and 64 of the grass gripping frame 60 as an attachment in FIG. 5 are considered as “one actuator” because they perform the same operation. FIG. 1 shows the detailed structure around the lift arm 3. The arm 3 is configured by integrating the first arm portion 3 a and the second arm portion 3 b, and the first arm portion 3 a is raised and lowered by the lift cylinder 5. An attachment such as a bucket or fork is detachably attached to the snap hitch 40 at the tip of the second arm portion 3b. This attachment is released or scooped by the dump cylinder 10. The above configuration is the same as the configuration and operation already described with reference to FIG.

 The selector valve 41 of the present invention is attached to the center of the connecting pipe 15 that connects the tip parts of the second arm part 3b. As shown in detail in FIGS. 2 to 4, the selector valve 41 includes a main body 43 having a spool valve 42 and a pair of first valves formed on the lower surface of the main body 43 and connectable to a load direction switching valve 44. 1 port X, Y and can be connected to a pair of left and right dump cylinders 10 formed on the left and right sides of the main body 43 via pipes P5, P6, and is always first through the passages 45, 46 in the main body 43. A pair of left and right second ports C1, D1, C2, and D2 communicated with the ports X and Y; a pair of third ports A and B formed on the front surface of the main body 43 and connectable to the first actuator of the attachment; A pair of fourth ports E and F formed on the upper surface of the main body 43 and connectable to the second actuator of the attachment are provided.

 As shown in FIG. 1, the pipe P <b> 5 extends linearly along the connecting pipe 15 and is connected to the rod side of the dump cylinder 10. The pipe P6 extends linearly along the connecting pipe 15, then bends at a right angle, extends a predetermined length along the lift arm 3 or the dump cylinder 10, and is connected to the bore side of the dump cylinder 10. In this way, by arranging the selector valve 41 having the distribution block function in the center of the dump cylinder 10 and on the connecting pipe 15, the pipes P5 and P6 are symmetrical and simple in shape and shortest. It can be a combination of a long I-shape and an L-shape. Such a pipe shape is effective for reducing the pressure loss of the hydraulic oil, and is also useful for preventing heat generation and preventing a decrease in operating speed.

 When there is no actuator on the left and right sides of the main body 43, plugs 47 and 48 are screwed together as shown in FIG. The plugs 47, 48 contain a washer 49 that contacts the flange surfaces 42 a at both ends of the spool valve 42 and a coil spring 50 that elastically presses the washer 49 against the seat surface of the main body 43 of the selector valve 41. When mounting the attachment with an actuator, as shown in FIGS. 2 to 4, either plug 47 or 48 is removed, and solenoid 52 is attached instead (this is referred to as “selector valve series”) instead. The solenoid 52 cuts off the communication between the first port X, Y and the second port C1, D1, C2, D2 and the first port X, Y and the third port A, B. The 1st moving means to move to the 1st position to perform is comprised. The solenoid 52 has a plunger 53 that abuts against the shaft end of the spool valve 42 or is opposed by a minute gap in addition to the internal configuration (washers and coil springs) of the plugs 47 and 48. When the plunger 53 energizes the coil of the solenoid 52, the plunger 53 moves to the right in FIG. 3 to move the spool valve 42 to the right against the coil spring 50 in the plug 48 on the opposite side. When the spool valve 42 moves to the right, the passages 45 and 46 are blocked by the spool valve 42, and instead, the first ports X and Y communicate with the third ports A and B through the passages 54 and 55.

  FIG. 5 is a pasture grasping frame 60 exemplified as an attachment with an actuator in the present embodiment. This grass gripping frame 60 has a pair of left and right slightly curved fence-like frames 61 and 61. The fence-like frames 61 and 61 are attached to both sides of the box-shaped frame 62 so as to be rotatable in the horizontal direction via hinges 63, and are opened and closed by extending and contracting the cylinders 64 and 64. The box-shaped frame 62 is detachably attached to a predetermined position of the snap hitch 40. The cylinders 64 and 64 are connected to the third ports A and B of the selector valve 41 via the pipes P9 and P10 and the branch block 65.

  FIGS. 6-8 shows the usage example of the selector valve 41 when mounting | wearing with the attachment without an actuator. In this case, the plugs 47 and 48 are screwed onto both sides of the main body 43 of the selector valve 41 as described above (for convenience, this is called “selector valve 0 series”). As a result, the surfaces of the flanges 42a and 42a at both ends of the built-in spool valve 42 abut against the washer 49 elastically pressed against the main body seat surface by the coil springs 50 in the left and right plugs 47 and 48. Therefore, the spool valve 42 is held in the neutral position, and the first ports X and Y and the second ports C1, D1, C2, and D2 are held in communication.

  Next, FIG. 9 to FIG. 11 show usage examples of the selector valve 41 when mounting an attachment equipped with two actuators. Here, “two actuators” means that a plurality of actuators that perform the same operation and a plurality of other actuators that perform the same operation. In this case, two solenoids 52 and 66 are attached to both sides of the main body 43 of the selector valve 41 in place of the plugs 47 and 48 (this is referred to as “two selector valves” for convenience). The solenoids 52 and 66 are the same as described above. When the coil of one solenoid 52 is energized, the first ports X and Y and the third ports A and B are communicated, and when the opposite solenoid 66 is energized, until now The communicating passage is blocked by the spool valve 42, and the first ports X and Y and the fourth ports E and F are communicated instead. That is, the solenoid 52 blocks the spool valve 42 from communicating with the first port X, Y and the second port, and communicates the first port X, Y with the third port A, B. The 1st moving means to move to is comprised. Further, the solenoid 66 moves the spool valve 42 to the second position where the communication between the first port X, Y and the second port is blocked and the first port X, Y and the fourth port E, F are communicated. A 2nd moving means is comprised.

  Similar to the solenoid 52, the solenoid 66 has a plunger 67 that abuts against the shaft end of the spool valve 42 or is opposed by a minute gap in addition to the internal configuration (washer and coil spring) of the plugs 47 and 48. When the plunger 67 energizes the coil of the solenoid 66, the plunger 67 moves to the left in FIG. 10 to move the spool valve 42 to the left against the coil spring 50 of the solenoid 52 on the opposite side. When the spool valve 42 moves to the left, the passage is blocked by the spool valve 42, and instead, the first ports X and Y communicate with the fourth ports E and F through the passages 68 and 69.

  The loader hydraulic circuit of the present invention is configured as described above. When an attachment without an actuator is attached to the loader, the solenoid 52 is not attached to the selector valve 41 as shown in FIGS. Alternatively, the solenoids 52 and 66 are used without being operated. As can be seen from FIGS. 7 and 8, as long as the spool valve 42 is held in the neutral position, the selector valve 41 functions in the same manner as a conventional distribution block, and the hydraulic pressure from the direction switching valve is supplied to the second ports C1, D1. , C2 and D2 are equally supplied to and discharged from the pair of dump cylinders 10.

  Next, when mounting one attachment on the loader, as shown in FIGS. 2 to 4, the solenoid 52 is attached to one side of the selector valve 41 (one selector valve), or the solenoids 52 and 66 are attached to both sides. Do not operate one of them even when installed. As can be seen from FIGS. 3 and 4, if the solenoid 52 is not operated, the spool valve 42 is held in the neutral position, the selector valve 41 functions in the same manner as the conventional distribution block, and the hydraulic pressure from the direction switching valve is the second. A pair of dump cylinders 10 are supplied and discharged evenly via ports C1, D1, C2, and D2. Further, when the solenoid 52 is energized, the first ports X and Y are communicated with the third ports A and B, and the cylinder 64 which is an attachment actuator can be operated while the dump cylinder 10 is stopped. .

  Next, when the actuator has two attachments attached to the loader, solenoids 52 and 66 are attached to the selector valve 41 and used as shown in FIGS. As can be seen from FIGS. 10 and 11, if the solenoids 52 and 66 are not actuated, the spool valve 42 is held in the neutral position, the selector valve 41 functions in the same manner as the conventional distribution block, and the hydraulic pressure from the direction switching valve is reduced. A pair of dump cylinders 10 are equally supplied and discharged through the second ports C1, D1, C2, and D2. Further, when the solenoid 52 is energized, the first ports X and Y are communicated with the third ports A and B, and the cylinder 64 which is an attachment actuator can be operated while the dump cylinder 10 is stopped. . When the solenoid 66 is energized, the first ports X and Y communicate with the fourth ports E and F, and the cylinder 70, which is another actuator of the attachment, is provided while the dump cylinder 10 and the cylinder 64 are deactivated. Can be activated.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made. The first and second moving means for moving the spool valve 42 are not limited to the solenoids 52 and 66 described above, and various actuators other than the solenoid can be used, or a manual lever or the like can be used instead of the actuator. Good. Various accessory valves such as a safety valve and a vacuum prevention valve can be mounted in the selector valve.

The perspective view of a loader. The selector valve in the case of one attachment actuator is shown, wherein (A) is a plan view, (B) is a front view, (C) is a bottom view, (D) is a left side view, and (E) is a left side view. Right side view. Sectional drawing of the selector valve which attached one solenoid in the case of one actuator of an attachment. The hydraulic circuit diagram of the selector valve which attached one solenoid when there is one actuator of an attachment. The perspective view of the grass-grasping frame as an attachment with an actuator. The selector valve in the state where the solenoid is not attached when there is no attachment actuator is shown, (A) is a plan view, (B) is a front view, (C) is a bottom view, and (D) is a left side view. (E) is a right side view. Sectional drawing of the selector valve of the state which does not have a solenoid attached when there is no actuator of an attachment. The hydraulic circuit diagram of the selector valve with no solenoid attached when there is no attachment actuator. (A) is a plan view, (B) is a front view, (C) is a bottom view, (D) is a left side view, and (E) is a right side view. Sectional drawing of the selector valve which attached two solenoids in the case of two actuators of an attachment. The hydraulic circuit diagram of the selector valve which attached two solenoids when there are two actuators of attachment. The schematic side view of a general loader. The perspective view of the conventional loader. The perspective view of the hydraulic distribution block used with the conventional loader. The disassembled perspective view in the case of connecting a selector valve to a distribution block with a conventional loader.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tractor 2 Main frame 3 Lift arm 5 Lift cylinder 8 Bucket 10 Dump cylinder 17 Distribution block 30 Selector valve 41 Selector valve 42 Spool valve 43 Selector valve main body 44 Direction switching valve 52 Solenoid 52, 66 Solenoid 60 Pasture grip frame 64 Cylinder (actuator )
70 cylinder (actuator)
X, Y 1st port C1, D1, C2, D2 2nd port A, B 3rd port E, F 4th port

Claims (2)

In the middle of the loader hydraulic piping from the direction switch valve of the loader connected to the pump to the dump cylinder of the loader,
A main body incorporating a spool valve, a first port connectable to the direction switching valve, and a second port connectable to the dump cylinder and normally communicated with the first port via a passage in the main body. A port, a third port connectable to a first actuator of an attachment attached to the loader, and a fourth port connectable to a second actuator of an attachment attached to the loader, and the main body In addition, the spool valve is disconnected from the first port and the second port, and is movable to a first position where the first port and the third port are communicated, and / or The spool valve is disconnected from the first port and the second port, and the second moving means capable of moving to the second position where the first port and the fourth port communicate with each other is detachably attached. Loader hydraulic circuit, characterized in that it is arranged a selector valve to only allow.   A pair of left and right dump cylinders are disposed on the loader, the selector valve is disposed at a substantially intermediate position of the dump cylinder, and the second ports are formed on both left and right sides of the selector valve body, respectively. Loader hydraulic piping characterized in that hydraulic piping is linearly arranged from two ports to the left and right dump cylinders, and the third port and the fourth port are provided in a direction orthogonal to the second port. .

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