JPH0352835Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a work tool angle control device for a front loader used for transporting and moving earth and sand.

(Prior Art) A front loader includes a column that is erected on both sides of a traveling vehicle such as a tractor, a boom that is pivotally supported on the top of the column so as to be able to swing vertically and extends forward, and the boom. a working tool such as a bucket that is pivotably supported at the tip of the boom in a vertically rotatable manner; a boom cylinder that is interposed between the boom and the support to move the boom up and down; and a working tool that is interposed between the boom and the working tool. This includes a work tool cylinder that rotates the tool in the vertical direction, and a control device that controls both cylinders.

The transportation work of earth and sand using the front loader is as follows:
First, the boom is lowered, the work tool (bucket) is placed horizontally on the ground, the tractor is moved forward to scoop dirt into the work tool, and then the boom is raised and dirt is removed from the work tool. Rotate the work implement upward to avoid spilling, move the tractor to the specified position, raise the boom further, rotate the work implement upward, and move the work implement downward when the boom is at its highest position. Rotate it to discharge the earth and sand inside the tool.

Thereafter, the boom is lowered and the tractor is moved to the original working position while rotating the work tool upward, and the work tool is grounded again and the above operation is repeated.

In the above-mentioned front loader work, the vertical movement of the boom and the rotation angle of the work tool are controlled by a control device.

As the control device, for example,
When the manual control valve described in the specification and drawings of No. 60-174380 is adopted, the boom cylinder and the work tool cylinder are operated independently or simultaneously with a single operating lever, so it requires skill to operate. However, there was a problem that beginners could not control it sufficiently.

Therefore, as a device for automatically controlling the rotation angle of a working tool, for example, the device described in the specification and drawings of Japanese Patent Application No. 60-61658 or the specification and drawings of Japanese Patent Application No. 171594-1982 has already been proposed. Proposed.

This conventional control device uses an electromagnetic valve for cylinder control, attaches a horizontal sensor to the work implement, or a limit switch, etc. near the pivot point between the work implement and the boom, and when the angle between the work implement and the boom reaches a predetermined angle. , which attempted to maintain the work implement at a predetermined angle by automatically turning off the electromagnetic valve.

(Problems to be Solved by the Invention) The conventional control device described above uses a solenoid valve, a limit switch, or a horizontal sensor, so it is very expensive, and if a failure occurs, it cannot be repaired by the user. There was a problem.

Additionally, there is a problem in that when a horizontal sensor is used, it may malfunction due to vibration or acceleration.

Further, when a limit switch is used, since the limit switch is installed near the pivot point between the work tool and the boom, there is a problem that earth and sand can hit the limit switch during scooping operations and cause damage.

Also, in the conventional model, the horizontal sensor and limit switch were fixedly attached, so
Unable to adjust the specified rotation angle of the work tool,
There were problems such as inconvenience in some tasks.

Therefore, the present invention uses a conventional manual control valve to make it inexpensive, allows for easy adjustment of a predetermined rotation angle of the work tool, and prevents damage to the work tool rotation angle detection part. An object of the present invention is to provide a work implement angle control device for a front loader.

(Means for solving the problems) In order to solve the above problems, the present invention takes the following measures. That is, the features of the present invention include a boom that can freely swing in the vertical direction, a working tool that is pivotally supported on the tip of the boom to be able to swing in the vertical direction, a cylinder that swings the boom, and a working tool that can swing freely in the vertical direction. a cylinder for rotating the work implement, a control device for controlling these cylinders, and a detection means for detecting an angle formed between the work implement and the boom, and the control device detects a predetermined angle by the detection means for rotating the work implement. In a work implement angle control device for a front loader configured to stop operation of a cylinder, the detection means includes a rod pivotally supported at a rear part of the work implement above a pivot point between the work implement and the boom; extends along the side of the boom, and a detection member is provided on the rod so as to be adjustable in the axial direction;
The boom is rotatably provided with a support member that slidably supports the rod, and the support member is provided with sensing means for sensing the approach of the detection member, and the sensing means and the control device are connected to each other. It is located at interlocking points.

(Function) According to the present invention, the vertical movement of the boom and the vertical rotation of the work tool are controlled by operating the control device.

First, we will explain the operation of setting the boom to the highest position, rotating the work tool downwards, draining the dirt inside the work tool, lowering the boom, and rotating the work tool upward to ground it in a horizontal position. .

After the earth and sand is discharged, the control device is operated to operate the boom cylinder and the work tool cylinder, lower the boom, and rotate the work tool upward.
The angle between the work tool and the boom becomes increasingly acute. At this time, the rod pivotally supported at the rear of the work implement is pushed rearward. This movement of the rod causes the detection member attached to the rod to approach the sensing means. Then, when the detection member and the sensing means reach a predetermined distance, the sensing means is activated, and the control device is activated to stop the operation of the work implement rotation cylinder.

During this stop, by setting the angle between the work implement and the boom to be the horizontal ground contact angle of the work implement, the work implement can be grounded horizontally.

Since the detection member is axially adjustable with respect to the rod, the angle at which the rotation of the work tool should be stopped can be adjusted by adjusting the position of the detection member.

Further, the rod is provided to extend rearward from above the pivot portion of the work tool and the boom, and the detection section and sensing means are located at the rear of the rod, so it is located away from the work tool. There is no risk of dirt, etc. hitting the sensing means.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

What is shown in FIG. 1 is a front loader 2 that is detachably attached to a tractor 1. As shown in FIG.

The front loader 2 includes a column 4 that is detachably attached to a mounting frame 3 fixed to both left and right sides of the tractor 1, and a column 4 that is pivotally supported on the upper part of the column 4 so as to be rotatable in the vertical direction and extends forward. boom 5
A dirt scooping work tool 7 is pivotally supported at the front end of the boom 5 via a pivot shaft 6 so as to be rotatable in the vertical direction, and a sand scooping tool 7 is interposed between the middle part of the boom 5 and the lower part of the support column 4. A boom cylinder 8, a work implement cylinder 9 interposed between the rear part of the work implement 7 above the pivot shaft 6 and the middle part of the boom 5, the midway part of the support column 4, and the front part of the vehicle body of the tractor 1. It is composed of braces 10 etc. that connect the

A control device 11 for controlling the boom cylinder 8 and the work implement cylinder 9 is attached to the mounting frame 3, and one operating lever 12 extends from the control device 11.

A detection means 13 is provided across the rear of the working tool 7 and the front end of the boom 5 to detect the angle formed by the working tool 7 and the boom 5.

This detection means 13 and the control device 11
are interlocked and connected by a push-pull wire 14.

FIG. 2 shows the hydraulic circuit of the front loader 2. The hydraulic pump 15 in the same circuit is driven by the engine 16 of the tractor 1. Hydraulic oil discharged from this hydraulic pump 15 is supplied to the work implement cylinder 9 and the boom cylinder 8 through the work implement control control valve 17 and the boom control control 18, causing each cylinder 8, 9 to expand and contract. The work tool 7 is rotated in the vertical direction, and the boom 5 is rocked in the vertical direction.

Each of the control valves 17 and 18 is provided within the control device 11, and each of the control valves 17 and 18 is manually operated by the operating lever 12.

The control device 11 is shown in FIGS. 3 to 5.
It is shown. The control device 11 has a control box 19 fixed to the mounting frame 3, and within the box 19 both control valves 17 and 18 are fixed with respective spools 20 and 21 movable in the vertical direction. A first support shaft 23 is rotatably supported on one side wall 22 of the control box 19 about a horizontal axis in the left-right direction, and a first rocker 24 is fixed to the inner end of the first support shaft 23. ing. This first oscillator 24
has front and rear walls that face each other in the front and rear directions via the axial extension line of the first support shaft 23, and has an arm 25 that projects forward from the edge of the front wall. A spool 21 of the boom control control valve 18 is pivotally attached to this arm 25.

The second vibrator 2 between the front and rear walls of the first vibrator 24
6 is provided. The second rocker 26 is rotatably supported by the front and rear walls via a second support shaft 27 having an axis in the front-rear direction that is perpendicular to the axis of the first support shaft 23 . A pin 28 coaxial with the first support shaft 23 is provided protruding from the second rocker 26.
A spool 20 of the control valve 17 for controlling the working implement is pivotally mounted to the spool 8 via a ball bearing.

The operating lever 1 is mounted on the upper surface of the second rocker 26.
2 is fixed, and the operating lever 12 extends upward from an opening 30 formed in the lid 29 of the control box 19.

In FIG. 3, when the operating lever 12 is tilted to the left (forward when viewed from the driver's side), the first rocker 24 rotates around the first support shaft 23, and the spool of the boom control control valve 18 is rotated. 21 is pushed downward, the boom cylinder 8 is contracted, and the boom 5 is lowered. Further, when the operating lever 12 is tilted to the right in FIG. 3, the boom 5 rises in the opposite manner to the above. In the left-right direction operation of the operation lever 12,
Since the pin 28 of the second rocker 26 is arranged coaxially with the first support shaft 23, the spool 20 of the control valve 17 for controlling the work tool is not operated.

When the operating lever 12 is tilted upward in FIG.
The second rocker 26 rotates around the second support shaft 27, and the spool 2 of the control valve 17 for controlling the work implement is rotated.
0 is pulled up, the implement cylinder 9 is extended,
The working tool 7 is rotated downward, and a so-called dumping operation is performed. On the contrary, by tilting the operating lever 12 downward in FIG. 3, the working tool 7 is rotated upward.
A so-called scooping operation is performed. Said operating lever 1
In the vertical direction operation in Figure 3 of 2, the second
The oscillator 26 only rotates around the second support shaft 27, and the first oscillator 24 does not rotate.

By tilting the operating lever 12 in the upper right diagonal direction, the upper left diagonal direction, the lower right diagonal direction, or the lower left diagonal direction in FIG. 3, the first rocker 24 and the second rocker 26 are rotated simultaneously. , the boom cylinder 8 and the implement cylinder 9 operate simultaneously.

The operating lever 12 is always maintained at a neutral position by spool biasing springs 31, 31 provided on each control valve 17, 18.

The operating lever 12 is provided with an engaging piece 32 that projects in the boom lowering and work implement scooping direction (diagonally downward left direction in FIG. 3). The tip of this engaging piece 32 is formed into a hook shape.

On the other hand, a hook 33 is provided on an extension line of the engaging piece 32 in the protruding direction, and is detachably engaged with the engaging piece 32. This hook 33 is rotatably supported by a mounting seat 34 which is movably and fixedly attached to the lid body 29. This hook 33 is urged upward by a spring 35, and the hook 33
The hook at the tip of the handle and the hook of the engagement piece 32 are removably engaged by tilting the operating lever 12 diagonally downward to the left in FIG.

The mounting seat 34 is mounted on the lid body 29 so that its mounting position can be freely adjusted in the left-right direction in FIG. By changing the position of this mounting seat 34, the operating lever 1 for engaging the hook 33 and the engaging piece 32
The inclination angle of the boom cylinder 8 is changed, thereby making it possible to freely adjust the contraction speed of the boom cylinder 8, that is, the lowering speed of the boom 5.

An inner wire attachment piece 36 is pivotally attached to the hook 33, and an inner wire 37 of the push-pull wire 14 is connected to this attachment piece 36. Outer wire 3 of push-pull wire 14
8 is attached to a wire receiver 39 fixed to the side wall of the control box 19.

By pulling the inner wire 37, the hook 33 is rotated against the spring 35 and disengaged from the engagement piece 32.

As shown in FIG. 6, the push-pull wire 1
4 is connected to the detection means 13. This detection means 13 has a rod 40 extending rearward from the rear of the working tool 7 along the inner surface of the boom 5. The front end of this rod 40 is pivotally supported at the rear of the working tool 7 above the pivot shaft 6 so as to be freely rotatable in the vertical direction.

The rear portion of the rod 40 is axially slidably supported by a support member 42 which is pivotally supported on the inner surface of the boom 5 via a mounting shaft 41 so as to be vertically rotatable.

On the rod 40 in front of the support member 42,
A detection member 43 is attached so as to be freely adjustable in the axial direction. This detection member 43 consists of a cam body 44 that is inserted through the rod 40 so as to be freely movable in the axial direction, and collars 45, 45 that fix the axial position of the cam body 44. By adjusting the position of the collar 45, The cam body 44 is positioned.

A sensing means 46 is rotatably supported on the mounting shaft 41. The sensing means 46 is composed of a bell arm, and when the front end thereof comes into contact with the cam body 44, the sensing means 46 is rotated around the mounting shaft 41. The inner wire 37 of the push-pull wire 14 is connected to the lower end of this sensing means 46. The outer wire 38 of this push-pull wire 14 is attached to a wire receiver 4 fixed to a support member 42.
It is fixed at 7.

Therefore, in FIG.
To explain the operation of lowering the lever to horizontally ground the work tool 7, first, the operating lever 12 is lowered in FIG. Even if you release your hand from the operating lever 12 in this engaged state, the operating lever 12
remains engaged. When the operating lever 12 is lowered to the scoop position, the boom 5 is lowered and the work tool 7 is rotated upward. Due to this rotation of the work tool 7, the rod 40 moves backward, and the detection member 43
contacts the sensing means 46, and the sensing means 46 rotates to pull the inner wire 37. This allows hook 3
3 is rotated downward to release the engagement with the engagement piece 32, and the operating lever 12 is returned to the neutral position by the springs 31, 31 of each spool 20, 21.
The lowering of the boom 5 and the rotation of the work implement 7 are stopped.

In this stopped state, the axial direction of the detection member 43 is determined so that the angle formed by the work tool 7 and the boom 5 is an angle that allows horizontal grounding.

Therefore, by subsequently operating the operating lever 12 in the boom lowering direction to lower only the boom 5, the work implement 7 is brought into contact with the ground.
and the ground becomes horizontal.

Further, since the lowering speed of the boom 5 is adjusted by adjusting the position of the mounting seat 34 of the hook 33, the optimum position of the boom 5 at which the engagement between the hook 33 and the engagement piece 32 should be released is determined by adjusting the position of the mounting seat 34. Obtained by position adjustment.

FIG. 7 shows another embodiment of the detection means 13, in which the mounting shaft 41 of the support member 42 and the pivot shaft 48 of the sensing means 46 are different.
is attached to the support member 42. Further, a cam body 44 is independently attached to the rod 40 so that its position can be adjusted.

In the case shown in FIG. 8, the position of the cam body 44 is freely adjustable via a pin 49, and the rod 40 has one pin hole, and the cam body 44 has three pin holes 50. provided, these pin holes 5
The position of the cam body 44 is adjusted by selecting 0.

9 and 10, the wire receiver 39 of the control box 19 is made adjustable, and the release point between the hook 33 and the engagement piece 32 is changed by changing the movement of the wire 14.

That is, the wire receiver 39 is rotatably fixed to the side wall of the control box 19, and the lock pins 52 of the wire receiver 39 are selectively engaged with the plurality of locking holes 51 provided in the side wall, thereby locking the outer wire 38. The end position can be changed freely.

What is shown in FIGS. 11 and 12 is one in which the detection means 13 and the control device 11 are electrically connected.

That is, the detection means 13 includes a detection member 43 provided on the rod 40 and a detection means 46 provided on the support member 42 to sense the approach of this detection member 43.
It consists of a sensor. This sensor 46 is composed of electrical sensors such as a proximity switch and a limit switch.

On the other hand, the hook 33 of the control device 11
is rotated by a solenoid 53, and this solenoid 5
3 and the sensor 46 are electrically connected, and the solenoid 53 is actuated upon sensing by the sensor 46, and the engagement between the hook 33 and the engagement piece 32 is released.

What is shown in FIG. 13 is a comparative example of the present invention, in which a cam 54 is provided on the rear surface of the working tool 7, a bell arm 55 is pivotally supported at the tip of the boom 5, and the working tool 7 is
The rotation of the cam 54 pushes the bell arm 55 and pulls the inner wire 37 connected to the bell arm 55.

With such a configuration, since the detection means 13 is located near the working tool 7, there is a risk that the detection means 13 will be hit by earth and sand and damaged.

Note that the present invention is not limited to the above embodiments.

(Effects of the invention) According to the invention, the detection means for detecting the angle formed between the work implement and the boom is provided above the pivot of the work implement and at a position extending rearward, so that it can be placed at a position far from the work implement. There is no risk of damage due to impact with earth and sand.

Furthermore, since the position of the detection member is adjustable, the angle between the work tool and the boom can be adjusted as desired, and the rotation of the work tool can be stopped in a state suitable for the working conditions.

[Brief explanation of the drawing]

Fig. 1 is an overall front view of a front loader showing an embodiment of the present invention, Fig. 2 is a hydraulic circuit diagram, Fig. 3 is a plan sectional view of the control device, Fig. 4 is a sectional view taken along the - 5 is a front sectional view, FIG. 5 is a sectional view taken along the - line in FIG. 3, FIG. 6 is a front view of the detection means, FIGS. 7 and 8 are plan views showing other embodiments of the detection means, 9 is a plan view showing another embodiment of the control device, FIG. 10 is a front view of the same, and FIG.
The figure is a front view showing the electric detection means, Fig. 12 is a sectional view showing a part of the control device, and Fig. 13 is a sectional view showing a part of the control device.
The figure is a front view showing a comparative example. 2...Front loader, 5...Boom, 6...
Pivot shaft, 7... Working tool, 8... Boom cylinder,
9... Work tool cylinder, 11... Control device, 13... Detection means, 14... Push-pull wire, 40... Rod, 42... Support member, 43
...Detection member, 46...Sensing means.

Claims (1)

[Scope of Claim for Utility Model Registration] A boom that can swing vertically, a working tool that is pivotally supported on the tip of the boom so that it can swing vertically, a cylinder that swings the boom, and a cylinder that rotates the working tool. a cylinder for rotating the work implement, a control device for controlling these cylinders, and a detection means for detecting an angle formed between the work implement and the boom, and the control device operates the work implement rotation cylinder by detecting a predetermined angle by the detection means. In a work implement angle control device for a front loader configured to stop a front loader, the detection means includes a rod pivotally supported at a rear part of the work implement above a pivot point between the work implement and the boom, and the rod is arranged to stop the work implement and the boom. A detection member is provided on the rod and extends along the side surface and is adjustable in the axial direction;
The boom is rotatably provided with a support member that slidably supports the rod, and the support member is provided with sensing means for sensing the approach of the detection member, and the sensing means and the control device are connected to each other. A work implement angle control device for a front loader characterized by interlocking connection.