JPH076211B2 - Front loader controller - Google Patents

Description

The present invention relates to a front loader control device.

(Prior Art) A front loader mounted on a vehicle body such as a tractor is pivotally supported on the vehicle body side so as to be vertically movable, and is pivotally supported on a tip end of the boom so as to be rotatable in a dumping / squeezing direction. A bucket control valve for controlling a boom cylinder for moving the boom up and down, and a bucket control valve for rotating the bucket. These control valves are independently operated by one operating lever. Simultaneous operation is possible.

When scooping soil into the bucket with this kind of front leader, if the bucket after dumping is grounded horizontally on the ground,
It is convenient because you can move forward immediately after touching down and scoop up the soil.

Therefore, electromagnetic valves are used as the control valves, and the boom lowering signal and the bucket upward rotation signal are electrically given to each control valve by operating the operating lever, while the angle of the bucket with respect to the boom is detected and the level is lowered in the horizontal direction. Japanese Patent Application No. 60-61658 proposes a control device that automatically returns the bucket control valve to the neutral position when the bucket rotates upward to the angle of contact with the ground.

(Problems to be Solved by the Invention) The conventional control device has a drawback that the manufacturing cost becomes very high because the electrical control using the solenoid valve is adopted.
Also, when operating the boom and bucket, during that time,
Since the operation lever had to be lowered and kept at the squeeze position, there was a drawback in that when the vehicle body was moved backward while moving the front loader side, a skill level was required for maneuvering.

In view of such conventional problems, the present invention makes it possible to use an inexpensive manual valve as a control valve, lower the operating lever to lock it in a state where it is operated at the squeeze position, and then release the hand. Also, the boom and bucket automatically move until the work implement reaches the horizontal grounding angle to facilitate maneuvering, and if the boom lowers to the transport position before the bucket reaches the horizontal grounding angle, stop the boom. An object of the present invention is to wait for the bucket to reach a horizontal ground contact angle, and to automatically unlock when the boom is below the transport position and when the bucket reaches a horizontal ground contact angle.

(Means for Solving Problems) As means for solving the problems, the present invention rotates a boom cylinder 9 for moving the boom 8 up and down and a bucket 11 pivotally supported at the tip of the boom 8 so as to be vertically rotatable. Control valves 15 and 16 that can operate the bucket cylinder 12 that operates independently and simultaneously
And one operating lever 1 for operating the control valves 15 and 16
4 is provided with an engaging portion 39, the engaging portion 39 engageably and disengageably engages when the operation lever 14 is in the lower squeeze position A, and the engaging portion 39 in the engaged state is neutral in the raising and lowering direction. The control box 23 provided on the vehicle body 1 is provided with the engagement tool 40 which is slidable to the side,
A stopper 45 for restricting the engaged portion 39 in the engaged state from sliding toward the neutral side is provided, and the stopper 45 is released when the boom 8 is at the carrying position B, and is below the carrying position B. The first detection releasing means 61 for operating the engaging member 40 to the releasing position C where the engaging portion 39 cannot be engaged with the engaging portion 39 via the stopper 45 when A second detection releasing means 72 for operating the engaging member 40 to the releasing position C via the stopper 45 when the angle is the horizontal ground contact angle is provided.

(Operation) When the operation lever 14 is lowered and operated to the squeeze position A, the engaging portion
39 engages with the engagement tool 40, and lowers the operation lever 14 to lock it at the squeeze position A. Further, the boom control valve 15 and the bucket control valve 16 are switched by the operation of the operation lever 14 at this time, the boom cylinder 9 contracts and the boom 8 lowers around the pivot 7, and the bucket cylinder 12 contracts and the bucket 11 moves. Squeezes upward around the pivot 10 at the tip of the boom 8. During this time, the engagement portion 39 is restricted to the engagement state by the stopper 45.

When the bucket 11 rotates to the horizontal grounding angle with respect to the boom 8, the second detection releasing means 72 detects it and causes the engaging tool 40 to release to the releasing position C. Therefore, the operating lever 1
4, the boom control valve 15 and the bucket control valve 16 return to neutral,
The bucket 11 automatically stops rotating upward at the horizontal ground contact angle.

When the carrying position B is reached while the boom 8 is descending, the first detection releasing means 61 detects it and releases the stopper 45, so that the engaging portion 39 remains engaged with the engaging tool 40 and is neutral in the raising and lowering direction. The boom 8 stops descending.

When the bucket 11 is near the dump end, the second detection releasing means 72 detects it and releases the engagement tool 40 to the release position C. Therefore, the bucket 11 can be vibrated in the vicinity of the dump end to remove soil.

(Example) Hereinafter, the present invention will be described in detail with reference to the illustrated example.
The figure exemplifies a bucket type front loader mounted on a tractor for use. In FIG. 4, 1 is a tractor body,
Reference numeral 2 is a driver's seat, and 3 is a mount, which are provided on both left and right sides of the tractor body 1.

Reference numeral 4 denotes a front loader, a column 5 detachably attached to the attachment base 3, and a brace 6 projecting forward from the column 5 and detachably attached to a front end portion of the tractor vehicle body 1.
A boom 8 pivotally supported by a pivot 7 on the upper end of the column 5; a boom cylinder 9 for vertically moving the boom 8; and a pivot 10 at the tip of the boom 8 pivotable in the dump / squeeze direction. Bucket 11 pivotally supported by
And a bucket cylinder 12 for rotating 11. A pair of the column 5, the brace 6, the boom 8, the boom cylinder 9, and the bucket cylinder 12 are provided on the left and right.

Reference numeral 13 is a control device, of the pair of left and right columns 5, the right column 5
The operating device 13 has a single operating lever 14 and is constructed as shown in FIGS. 1 to 3.

1 to 3, 15 is a boom control valve for controlling the boom cylinder 9, 16 is a bucket control valve for controlling the bucket cylinder 12, and these control valves 15 and 16 are spool type three-position switching valves. The spools 17 and 18 are fixed to the mounting plate 19 so as to extend in the vertical direction. The mounting plate 19
Is the bracket 22 of the column 5 through the bolt 20 and the spacer 21.
It is fixed to. 23 is a control box, which is a control valve
This control box is fixed to the mounting plate 19 above
Inside 23, an interlocking mechanism 24 is provided for enabling the control valves 15 and 16 to be operated independently and simultaneously by one operating lever 14. The interlocking mechanism 24 includes a first oscillating member 27 and a second oscillating member 28, which are swingable around the axes of a first shaft 25 and a second shaft 26 which are orthogonal to each other. The operation lever 14 is fixed to. In addition, the operation lever 14 is a top plate portion 29 of the control box 23.
It is projected upward from the opening 30 formed in the. First
The oscillating member 27 is U-shaped, has a first shaft 25 in the left-right direction, and the first shaft 25 is rotatably inserted into a boss portion 31 fixed to the mounting plate 19. The first oscillating member 27 has an arm portion 32 protruding rearward, and the arm portion 32 is connected to the spool 17 of the boom control valve 15 via a pin 33, a rod 34, and a pin 35. The second oscillator 28 is pivotally supported in the first oscillator 27 by a second shaft 26 in the front-rear direction.
Has a projecting portion 36 projecting in the opposite direction on the axis of the first shaft 25. The protrusion 36 is connected to the spool 18 of the bucket control valve 16 via a ball receiver, a rod 37, and a pin 38. Therefore, as shown in FIG. 10, the operating lever 14 can be swung in the front / rear lowering / raising directions around the respective shafts 25, 26 and in the right / left squeeze / dump directions, and at the same time, can be operated around the respective shafts 25, 26. By the combined movement of the oscillating elements 27 and 28, it is possible to freely oscillate in each intermediate direction, and the control valves 15 and 16 are independently linked to the front and rear, left and right operations of this operating lever 14, and the intermediate direction The control valves 15 and 16 are simultaneously linked to the operation of.
The operating lever 14 is urged to be in the neutral position N by a neutral return spring incorporated in the control valves 15 and 16.

An engaging portion 39 is provided so as to protrude toward the squeeze direction side in a state of being slightly inclined from the base portion of the operation lever 14 toward the lowering direction side. 40 is an engaging tool, which is a control box
Inverted U-shaped bracket attached to the lower side of the top plate 29 of 23
A shaft 41 is pivotally supported about a shaft 42 so as to be vertically movable, and is urged upward by a winding spring 43 so as to contact the top plate 29 side. At the tip of the engaging member 40, an engaging body 44 is projected rearward so that the engaging portion 39 can engage with and disengage from the upper side. The engaging portion 39 is slidable rearward while being engaged with the engaging body 44, and the operation lever 14 is lowered to the squeeze position A.
When it is in, it is regulated by the stopper 45. The stopper 45 is a notch formed in the engaging body 44 as shown in FIG.
The distal end portion is arranged at 46, and the base portion side is fixed to the rear end portion of the pivot shaft 42. A link 47 is fixedly attached to the front end of the pivot 42, and the link 47 is connected via a connector 48.
It is connected to a link 50 fixed to the horizontal axis 49. The horizontal shaft 49 is rotatably supported by a boss portion 52 fixed to a side plate 51 of the control box 23, and the horizontal shaft 49 has an L-shaped link 53.
The base of an emergency release lever 55 that projects rearward from the rear side plate 54 of the control box 23 is supported so as to be vertically movable. The release lever 55 is provided with a pin 56, and the pin 56 is inserted into the long hole 57 of the link 53.
The release lever 55 is biased by a spring 58 to defoam. The rear plate 54 of the control box 23 has a long hole through which the release lever 55 is inserted.
59 is formed in the vertical direction, and an engaging recess 60 for retaining the release lever 55 at the release position is formed at the lower end of the long hole 59.

Reference numeral 61 denotes a first detection releasing means for detecting the position of the boom 8 and actuating the stopper 45. When the boom 8 is at the transportation position B shown in FIG.
When the boom 8 is below the carrying position B, the engaging tool 40 is pulled down to the lower releasing position C (see FIG. 7) via the stopper 45 when the boom 8 is below the carrying position B. Is configured to. That is, the first detection canceling means 61
Is a detection arm having a cam plate 63 attached via a bracket 62 to the inside of the base of the right boom 8 of the pair of left and right booms 8, and a cam driven roller 64 corresponding to the cam plate 63.
65 and. The cam plate 63 has an arc shape centered on the pivot 7, and has a first cam portion 66 and a second cam portion 67 in a step shape. The detection arm 65 is slidably supported by a support shaft 5 by a pivot shaft 68, and is biased by a spring 69 so that the cam driven roller 64 contacts the cam plate 63 side, and is regulated by a stopper 70. . The detection arm 65 has a turnbuckle structure, and the link 53 of the horizontal axis 49 via the rod 71 which is the expansion and contraction adjustment itself.
Therefore, if the detection arm 65 swings around the pivot 68, the rod 71, the link 53, the horizontal shaft 49, and the link 5 are connected.
Stopper 45 via 0, connector 48, link 47, and pivot 42
Rotates up and down around the pivot 42. At the release position C, the engagement portion 39 cannot engage with the engagement body 44 of the engagement tool 40.

Reference numeral 72 denotes a second detection releasing means for detecting the angle of the bucket 11 with respect to the boom 8 and actuating the stopper 45. When the angle formed by the bucket 11 and the boom 8 becomes the horizontal ground contact angle, The stopper 45 pulls down the engagement tool 40 to the release position C when is near the dump end. That is, the bucket 11 is pivotally supported at the tip of the boom 8 as shown in FIG.
3, the bucket cylinder 12 is configured to be rotated via the rod 74, and the second detection releasing means 72 is provided between the link 73 and the boom 8. The link 73 is slidably supported by a bearing 75 on the boom 8 by a pivot 75A. The second detection releasing means 72 is shown in FIGS.
Bracket inside base of right link 73 as shown
It comprises a cam plate 77 attached via 76, and a detection arm 79 having a cam driven roller 78 corresponding to the cam plate 77. The cam plate 77 has an arc shape centered on the pivot 75A,
A first cam portion 80 and a second cam portion 81 are provided at both ends in the arc direction. The detection arm 79 is swingably supported by a pivot 82 fixed to the boom 8 on the tip side of the pivot 75A, and a cam follower roller 78 is urged by a spring 83 so as to contact the cam plate 77. . One end of the inner 85 of the push-pull wire 84 is connected to the tip of the detection arm 79, and the other end is connected to the metal 86 of the rod 71 by the pin 87. The outer 88 of the push-pull wire 84 has a boom 8 at one end.
Is attached to an outer receiver 89 fixed to the column 5, and the other end is attached to an outer receiver 90 fixed to the column 5 above the pivot 68. The other end of the push-pull wire 84 is the inner
85 is substantially parallel to the rod 71. Cam part of cam plate 77
Reference numerals 80 and 81 are for swinging the detection arm 79 via the cam follower roller 78. The first cam portion 80 pushes and swings the detection arm 79 when the bucket 11 reaches the horizontal grounding angle, and the second cam portion 80 is also used. The portion 81 is configured to push and swing the detection arm 79 within a range in which the bucket 11 swings about 10 degrees near the dump end.

Next, the operation will be described. When the operating lever 14 is operated in the dumping direction at the most raised position of the boom 8, the second oscillating member 28 moves to the second shaft.
It swings around 26 and pulls the spool 18 of the bucket control valve 16 upward through the protrusion 36 and the rod 37, so that the bucket cylinder 12 extends and the bucket 11 performs a dump operation around the pivot 10 to remove soil and sand. discharge. At this time, if the dump cylinder 12 extends to the vicinity of the dump end, the link 73 is at the position of the virtual line D in FIG.
Since the second cam portion 81 of the 77 pushes the detection arm 79 via the cam driven roller 78, the stopper is provided via the push-pull wire 84, the metal fitting 86, the link 53, the horizontal shaft 49, the link 50, the connector 48, and the link 47. 45 rotates downward about the pivot 42,
To the release position C in FIG. Therefore, after discharging the soil, if the operation lever 14 is operated in the left and right dump directions and the squeeze direction to expand and contract the bucket cylinder 12,
11 repeats dump and squeeze operation, and by its vibration,
Soil adhering to the bucket 11 can be dropped. The amount of movement of the bucket 11 at this time is about 10 degrees, and the cam driven roller 78 remains in contact with the second cam portion 81.
40 is held at the release position C, and the engaging portion 39 of the operation lever 14 does not engage with the engaging body 44 of the engaging tool 40.

In the dumped state of the bucket 11, as shown in FIG. 10, the operation lever 14 is moved from the neutral position N to the lowered position in the dimension a.
When the operation lever 14 is operated in the squeeze direction to the squeeze position by a dimension b and set to the lower squeeze position A, the engagement portion 39 engages with the engagement body 44 of the engagement tool 40 from above. Then, the operation lever 14 is locked at the lowering swivel position A.

That is, the operation of the operation lever 14 in the lowering direction causes the first oscillating member 27 to oscillate about the first shaft 25, and the spool 17 of the boom control valve 15 is pulled upward via the arm portion 32 and the rod 34. The boom cylinder 9 contracts and the boom 8 descends around the pivot 7. On the other hand, when the operation lever 14 is operated in the squeeze direction, the second oscillating element 28 oscillates around the second shaft 26, and the rod 37
Since the spool 18 of the bucket control valve 16 is pushed downward via the, the bucket cylinder 12 contracts and the bucket 11 squeezes upward around the pivot 10. Therefore, the boom 8
And the squeezing operation of the bucket 11 are performed at the same time. On the other hand, when the bucket 11 starts squeezing,
Since the cam driven roller 78 is disengaged from the second cam portion 81 of the cam plate 77 of the second detection releasing means 72, and the detection arm 79 is pulled back by the spring 83, the engagement tool 40 is rotated upward by the spring 43, As shown by the solid line in FIG. 6, the engagement portion 39 engages with the engagement body 44 of the engagement tool 40,
The operation lever 14 is lowered and locked at the squeeze position A. At this time, the engaging portion 39 is regulated by the stopper 45 and is in the state shown by the solid line in FIG.

When the boom 8 descends and reaches the transport position B, as shown by the solid line in FIG. 11, the first cam portion 66 of the cam plate 63 of the first detection releasing means 61 causes the detection arm via the cam driven roller 64. Since 65 swings, the stopper 45 is pulled down from the rod 71 into the notch 46 of the engaging body 44 via the link 53 and the like, and the restriction on the engaging portion 39 is released. Therefore, the operating lever 14
Since the spring force of the neutral return spring incorporated in the boom control valve 15 and the bucket control valve 16 acts to return to the neutral position N via the spools 17 and 18, the stopper 45
Is lowered downward, the operating lever 14 is pushed back by the neutral return spring of the boom control valve 15, so that the engaging portion 39 is engaged.
While still engaged with the engaging body 44 of 40, it slides in the direction of arrow E in FIG. 10, the operating lever 14 returns to the play range d in the raising direction, and the spool 17 of the boom control valve 15 returns to neutral. Then, the boom 8 stops at the transportation position B.

On the other hand, when the bucket 11 is squeezed to the horizontal grounding angle, the detection arm 79 is swung by the first cam portion 80 of the cam plate 77 of the second detection releasing means 72, and the stopper 45 is moved downward via the push-pull wire 84. Since it is pulled down, the engagement tool 40 is pulled down to the release position C. Therefore, the engaging portion 39 disengages from the engaging body 44 and unlocks the engaging tool 40, so that the spool 18 of the bucket control valve 16 returns to the neutral position by its neutral return spring, and the bucket 11 stops. The operation lever 14 returns to the neutral position.

It should be noted that when the squeeze motion amount until the bucket 11 reaches the horizontal ground contact angle is small, even if the boom 8 is lowered to the transport position B, the engaging member is engaged by the second detection releasing means 72.
Since 40 is pulled down to the release position C, the boom 8 stops descending. Therefore, when the bucket 11 reaches the horizontal ground contact angle, the boom 8 and the bucket 11 always stop.

Next, when the operation lever 14 is operated in the lowering direction, the first oscillating member 27 oscillates around the first shaft 25, and the spool 17 of the boom control valve 15 is pulled upward via the arm portion 32 and the rod 34. As it is raised, the boom cylinder 9 contracts and the boom 8 descends.
During this time, since bucket 11 is in the stopped state,
If 11 is grounded, the bottom surface 11a is always grounded in a horizontal state.

When the boom 8 is lowered below the carrying position B, the second cam portion 81 of the cam plate 77 of the second detection releasing means 72 pushes the detection arm 79, so that the engaging tool 40 is in the releasing position C, and accordingly, Even when the bucket 11 is not at the horizontal grounding angle, the engaging portion 39 is
It does not engage the engagement body 44 of 40. Also, bucket 11
When simply squeezing, the operating lever 14 may be operated as it is from the neutral position N in the squeeze direction. At this time, since the engaging body 44 is displaced forward, the engaging portion 39 engages with the engaging body of the engaging tool 40. 44 does not engage.

(Effect of the Invention) According to the present invention, the engagement portion 39 is engaged with the engagement tool 40 and locked at the lower squeeze position of the operation lever 14, and when the bucket 11 reaches the horizontal ground contact angle, Second detection releasing means
Since the engagement tool 40 is operated to the release position C where 72 is not engageable with the engagement portion 39 by the 72, even if the hand is released after the operation lever 14 is lowered to the squeeze position, the boom 8 will not move. When the bucket 11 moves down, the bucket 11 makes a squeeze operation, and the bucket 11 can be automatically stopped at the horizontal ground contact angle, which makes the maneuvering much easier than in the conventional case. Further, since the operation lever 14 is mechanically held by the engagement tool 40, a cheap manual valve can be used as the control valve 16 and the manufacturing cost can be reduced. Moreover, the engaging portion 39 is slidable toward the neutral side in the raising and lowering direction with respect to the engaging tool 40, and the stopper 39
The engaging portion 39 is lowered by 45 and regulated to the squeeze position A, and when the boom 8 reaches the carrying position B, the first detection releasing means 61.
Since the stopper 45 is released by the, the boom 8 is moved to the transport position B before the bucket 11 reaches the horizontal grounding angle.
When it goes down, the boom 8 stops at that position,
The bucket 11 can be surely set to the horizontal ground contact angle.
Further, when the boom 8 is lower than the carrying position B, the first detection releasing means 61 operates the engaging tool 40 to the releasing position C. Therefore, even if the operating lever 14 is operated thereafter, The joint portion 39 does not engage with the engagement tool 40 and can be operated freely. Further, since the engagement tool 40 is released by the first and second detection releasing means 61, 72 via the stopper 45, it is not necessary to separately operate the stopper 45 and the engagement tool 40, and the structure is simplified. it can.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a sectional side view of a control device, FIG. 2 is a sectional rear view thereof, FIG. 3 is a sectional plan view, and FIG. FIGS. 5 and 5 are sectional views of the engaging body portion, FIGS. 6 and 7 are operation explanatory views of the engaged state, FIG. 8 is a side view of the second detection releasing means, and FIG. 9 is a rear view thereof. FIG. 10 is an operation explanatory view, and FIG. 11 is an operation explanatory view of the first detection releasing means. 1 ... tractor body, 4 ... front loader, 8 ... boom, 9 ... boom cylinder, 11 ... bucket, 12 ...
Bucket cylinder, 13 …… Control device, 14 …… Operating lever, 15 …… Boom control valve, 16 …… Bucket control valve, 21…
... interlocking mechanism, 39 ... engaging part, 40 ... engaging tool, 44 ... engaging body, 45 ... stopper, 61 ... first detection releasing means, 72 ...
... second detection releasing means, A ... lowering rake position, B ... transporting position, C ... releasing position.

Claims (1)

[Claims] 1. A boom cylinder (9) for vertically moving a boom (8) and a bucket cylinder (12) for rotating a bucket (11) pivotally supported at the tip of the boom (8) so as to be vertically rotatable. ) And control valve that can be operated independently and simultaneously (15)
(16), the engaging portion (39) is provided on one operation lever (14) for operating the control valves (15) and (16), and the operation lever (14) is at the lower squeeze position (A). At a certain time, the engaging portion (39) engages in a disengageable manner, and the engaging portion (39) in the engaged state is slidable toward the neutral side in the up and down direction.
0) is provided in the control box (23) provided on the vehicle body (1),
A stopper (45) is provided to prevent the engaged portion (39) in the engaged state from sliding toward the neutral side, and the stopper (45) is provided when the boom (8) is at the carrying position (B). And the engaging tool (40) through the stopper (45) when it is released and is below the carrying position (B).
Is provided with a first detection releasing means (61) for operating the engaging portion (39) to a disengageable position (C) where the bucket (1
Second detection release means (72) for operating the engagement tool (40) to the release position (C) via the stopper (45) when the angle formed by 1) and the boom (8) is a horizontal ground contact angle. ) Is provided, the control device for the front loader.