JP3173895B2 - Backhoe hydraulic cylinder stop structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for stopping a hydraulic cylinder of a backhoe for driving a backhoe device provided on a swivel base.

[0002]

2. Description of the Related Art In a backhoe, the outermost part of a driving unit is
Checking a certain distance outward from the covering external frame
The surface is set to a space, and the bucket of the backhoe device is the check surface.
The control valve to neutral when trying to
Return to the position to stop the hydraulic cylinder at the set telescopic position
To stop the bucket on the check surface,
Are configured so that they do not touch the external frame
is there.

In this case, shortly before the bucket reaches the check surface, the flow rate of the hydraulic oil supplied to and discharged from the hydraulic cylinder is suppressed, the hydraulic cylinder is decelerated, and the bucket is smoothly stopped at the check surface. are doing. Also, when the hydraulic cylinder reaches the stroke end (another example of the set expansion / contraction position) , shortly before reaching the stroke end, as described above, the flow rate of the hydraulic oil supplied / discharged to the hydraulic cylinder is suppressed to reduce the hydraulic pressure. The cylinder is decelerated so that the hydraulic cylinder stops smoothly at the stroke end.

On the other hand, in the backhoe,
The surface of the space separated from the control surface by a predetermined distance outward and the check surface
The check area is set between and the bucket is located in the check area.
The bucket is level until it reaches the check surface.
The shortest distance in the direction is calculated, and the bucket approaches the check surface
Is configured to reduce the expansion and contraction speed of the hydraulic cylinder
There are some.

[0005]

THE INVENTION Problems to be Solved] of those of the former described above
Shortly before the hydraulic cylinder reaches the set telescopic position corresponding to the restraining surface or the set telescopic position such as stroke end,
When decelerating the hydraulic cylinder while suppressing the flow rate of hydraulic oil, if the deceleration rate of the hydraulic cylinder is set based only on the distance between the set telescopic position and the hydraulic cylinder, the closer the hydraulic cylinder approaches the set telescopic position, The deceleration rate increases.
As a result, if the hydraulic cylinder is approaching the set expansion / contraction position at a relatively low speed, the hydraulic cylinder is sufficiently decelerated even if the deceleration rate is set only by the distance as described above. Then, the hydraulic cylinder stops smoothly at the set telescopic position. However, if the hydraulic cylinder is approaching the set telescopic position at a relatively high speed, the deceleration operation of the hydraulic cylinder is delayed, and the hydraulic cylinder does not stop smoothly at the set telescopic position. The backhoe device and the like may be shaken by the shock.

[0006] In the latter case, the check
Only by the shortest horizontal distance from the surface to the bucket,
The deceleration rate of the operating speed of the hydraulic cylinder is set.
This allows the bucket to be approximately horizontal from a position in the restraint area.
When approaching the check surface, the bucket is close to the check surface.
As the hydraulic cylinder is decelerated as
When the bucket reaches the check surface, the hydraulic cylinder is stopped.
The operator's operational sensation and back
The operating condition of the hoe device matches,
The unit moves diagonally upward from a position in the check area, and
Water from the restraint surface
Since the deceleration rate is set at the shortest distance in the horizontal direction,
Distance until the ket reaches the check surface (in a diagonally upward direction)
Distance) is relatively long, but it is almost the same as moving horizontally.
In a state where the hydraulic cylinder is decelerated
Become. This allows the bucket to rise slightly in the restraint area.
Since it is too late, there is room for improvement in operability.
You.

A first object of the present invention is to provide a battery as described above.
While operating the hydraulic cylinder for driving the Kubo device
The backhoe configured to stop at the set telescopic position
In the hydraulic cylinder stop structure, the expansion / contraction speed of the hydraulic cylinder
Regardless of the degree, the hydraulic cylinder is smooth at the set telescopic position
The second purpose is to configure to stop.
The backhoe that sets the check surface and check area as described above
C) when the bucket is located in the check area
It is to improve operability.

[0008]

In order to achieve the above object, the present invention provides a position sensor for detecting a telescopic position of a hydraulic cylinder for driving a backhoe device provided on a swivel, and a detection value of the position sensor. When the hydraulic cylinder reaches the set telescopic position based on the control means, the control valve for supplying and discharging hydraulic oil to the hydraulic cylinder is returned to the neutral position, and stop means for stopping the hydraulic cylinder at the set telescopic position. together comprising a detector for detecting the expansion and contraction direction and expansion rate of the hydraulic cylinder, said in a state in which the hydraulic cylinder is approaching the set stretch position, the distance of the hydraulic cylinders and the set stretch position location is small, the higher stretching speed of the hydraulic cylinder is large, the deceleration for decelerating operation of the hydraulic cylinder by suppressing the flow rate of hydraulic oil supplied to and drained operated to the hydraulic cylinder And a stage, further prepare for the swivel deck
From the external frame that covers the outermost part of the operating unit
A first setting method for setting a check surface separated by a predetermined distance in space
Steps and a space that is outwardly separated from the restraining surface by a predetermined distance.
Setting means for setting a check area between the surface and the check surface
And a step , based on the detection values of the position sensor and the detection means.
Then, the position of the bucket of the backhoe device,
Calculate the moving direction of the bucket and the moving speed of the bucket.
The bucket is located in the restraint area.
The bucket is forward from a position in the current check area.
The distance traveled taking into account the direction of travel up to the check
Calculation, and the bucket moves
At the time of prediction from the position in the check area to the check surface
Computing means for calculating the interval, wherein the deceleration means comprises:
The direction in which the bucket moves has a large component moving to the check surface
And the shorter the predicted time, the more the hydraulic cylinder
The flow rate of hydraulic oil supplied and discharged to the
Hydraulic cylinder stop structure of the backhoe configured to decelerate the cylinder.

[0009]

According to the present invention, the extension / contraction position, extension / contraction direction and extension / contraction speed of the hydraulic cylinder are detected while the backhoe device is driven by the hydraulic cylinder. Accordingly, if the hydraulic cylinder is close to the set expansion / contraction position to be stopped and the expansion / contraction speed at which the hydraulic cylinder approaches the set expansion / contraction position is high, it can be determined that the hydraulic cylinder will reach the set expansion / contraction position relatively quickly. The flow rate is suppressed and the hydraulic cylinder is decelerated. Therefore, before the hydraulic cylinder reaches the set telescopic position, the hydraulic cylinder is decelerated without delay, so that the hydraulic cylinder smoothly stops at the set telescopic position with less shock.

Conversely, if the hydraulic cylinder is far from the set expansion / contraction position to be stopped and the expansion / contraction speed at which the hydraulic cylinder approaches the set expansion / contraction position is slow, it can be determined that the hydraulic cylinder reaches the set expansion / contraction position relatively slowly. The hydraulic cylinder is not decelerated very much. This reduces the likelihood of the hydraulic cylinder being excessively decelerated while the hydraulic cylinder has a relatively long distance until the hydraulic cylinder reaches the set telescopic position.

Further, according to the present invention, the bucket is controlled by a check.
In the state where it is located within the area,
Bucket based on the current position and direction of the bucket
The moving direction of the unit 6 is, for example, the velocity vector V shown in FIG.
Those with relatively large movement components to the check surface, such as direction 1
Direction, the current position of the bucket 6 is
As the moving distance to A1, the moving distance L1 shown in FIG.
Are relatively short distance is calculated as, conversely, the bucket 6
Is moving in the direction of the velocity vector V2 shown in FIG. 3, for example.
In the direction where the movement component to the check surface is relatively small like
In some cases, from the current position of the bucket 6, the check surface A1
The moving distance up to the moving distance L2 shown in FIG.
A relatively long distance is calculated. And
If the calculated moving distance is relatively short,
Of the bucket 6 detected by the moving distance and the speed sensor
Based on the current traveling speed, the bucket 6
A relatively short time as the predicted time to reach A1
Is calculated, and the bucket 6 reaches the check surface A1 relatively quickly.
Hydraulic pressure for driving the backhoe device
The operation speed of the cylinder is decelerated. Reverse
If the calculated moving distance is relatively long,
Bucket detected by the moving distance and speed sensor
6 based on the current traveling speed of the bucket 6
When the estimated time to reach the control surface A1 is relatively long
The interval is calculated, and the bucket 6 moves relatively slowly to the check surface A1.
Is determined to be reached.
The operating speed of the hydraulic cylinder should not be reduced too much
become.

[0012] Thereby, the bucket is located within the check area.
Moving diagonally upward from the position and gradually approaching the
Movement until the bucket reaches the check surface, as in
The moving distance (the distance along the moving direction of the bucket) is relatively long
However, it seems that the moving speed of the bucket is too slow
Less.

[0013]

Thus, according to the present invention, in the backhoe hydraulic cylinder stopping structure, when the expansion / contraction position, the expansion / contraction direction, and the expansion / contraction speed of the hydraulic cylinder are detected, the hydraulic cylinder stops when reaching the preset expansion / contraction position to be stopped. The deceleration operation of the hydraulic cylinder is performed smoothly without delaying or excessively decelerating the hydraulic cylinder, and the hydraulic cylinder can be stopped at the set telescopic position with less shock, and The shaking was reduced, and the riding comfort of the backhoe was improved.

In addition, a check surface and a check area are set.
Position of the bucket within the check area
Position, moving direction, and moving speed
Prevent the situation where the movement speed of the unit becomes too slow
Can be operated by the operator and the operation of the backhoe device
Be able to match the state, back
The operability of the hoe could be improved.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 7 shows the whole side surface of the backhoe. A traveling device 1 of a rubber crawler type supports a dozer 20 and a swivel 2 at an upper portion thereof, and a backhoe 3 is provided at a front portion of the swivel 2. The backhoe device 3 includes the hydraulic cylinder 1
1 comprises a boom 4 which is swingably driven up and down, an arm 5 which is swingably driven back and forth by a hydraulic cylinder 12, and a bucket 6 which is swung and driven by a hydraulic cylinder 13. A hydraulic motor 14 is provided for driving the turntable 2 to turn.

As shown in FIGS. 7 and 5, the boom 4 of the backhoe device 3 swings up and down about a first boom portion 4a and a shaft P1 at the front end of the first boom portion 4a. The second boom portion 4b is connected, and a support bracket 4c is swingably connected around an axis P2 at the front end of the second boom portion 4b. The arm 5 is connected to the support bracket 4c. 1st boom part 4a
A link 4 is erected between the support bracket 4c and the support bracket 4c to form a parallel quadruple link. The swing operation of the second boom portion 4b by the hydraulic cylinder 7
The arm 5 and the bucket 6 can be moved left and right in parallel.

As shown in FIG. 6, a control valve 21 for the hydraulic cylinder 11 of the first boom part 4a, a control valve 25 for the hydraulic cylinder 7 of the second boom part 4b, a control valve 22 for the hydraulic cylinder 12 of the arm 5, a bucket 6 is provided with a control valve 23 for the hydraulic cylinder 13 and a control valve 24 for the hydraulic motor 14 of the swivel 2. The control valves 21 to 25 are of a three-position switching type and of a pilot operation type, and the flow rate can be controlled by adjusting the opening based on the pilot pressure. For the control valves 21 to 25, pilot valves 31 a, 31 b, 32 a, 32 b, 33 a, 33 of an electromagnetic proportional pressure reducing valve type for generating a pilot pressure for opening operation are provided.
b, 34a, 34b, 35a, and 35b are provided.

As shown in FIGS. 5, 6, and 7, the swivel 2 is provided with a right operating lever 9 and a left operating lever 10.
The right and left operation levers 9 and 10 are freely operable back and forth and left and right. The potentiometer 15 detects the operation position of the right operation lever 9 in the front-rear direction and the potentiometer 16 detects the left and right operation position of the right operation lever 9. In addition, a potentiometer 17 for detecting the operating position of the left operating lever 10 in the front-rear direction and a potentiometer 18 for detecting the operating position of the left operating lever 10 in the left-right direction are provided. The operation signals of the potentiometers 15 to 18 are transmitted to the control device 19.
Has been entered. An operation pedal 2 is provided at the lower front part of the swivel 2
6 is provided, and an operation signal of the operation pedal 26 is transmitted to the control device 1.
9 has been entered.

With the above configuration, when the right operation lever 9 is operated forward or backward, the pilot valve 31 is operated based on the operation.
When the control valve 21 is operated on the lower side or the upper side of the boom 4 and the right operating lever 9 is operated right or left, the pilot valve 33 based on the pilot pressure is generated.
The control valves 23a and 33b generate pilot pressure, and the control valve 23 is operated to the discharging side or the scraping side of the bucket 6. When the left operating lever 10 is operated forward or backward, the pilot valves 32a and 32b generate pilot pressure based on this, the control valve 22 is operated to the discharging side or the scraping side of the arm 5, and the left operating lever 10 is moved to the right. Or, when operated to the left, the pilot valves 34a and 34b generate pilot pressure based on this,
The control valve 24 is operated to the right turning side or the left turning side. When the operation pedal 26 is depressed to the right or left, the pilot valves 35a and 35b generate pilot pressure based on this, and the control valve 25 is operated to the right or left swing side of the second boom portion 4b.

In the above operation, the potentiometers 15 to 18 of the right and left operation levers 9 and 10 detect not only the operation directions of the right and left operation levers 9 and 10 but also the operation amounts from the neutral position. As a result, the larger the operation amounts of the right and left operation levers 9 and 10 are, the larger the pilot valve 31a is.
３４34b becomes large, and the control valves 21 to 24
Is operated to the large flow rate side. That is, the larger the right and left operation levers 9 and 10 are operated, the more the hydraulic cylinders 11 to 13
And the hydraulic motor 14 operates at a high speed.

As shown in FIGS. 6 and 7, a potentiometer 36 for detecting the vertical angle of the boom 4 (first boom portion 4a), a potentiometer 37 for detecting the right and left angle of the second boom portion 4b, and front and rear of the arm 5 A potentiometer 38 for detecting an angle is provided, and detection signals from the potentiometers 36, 37, and 38 are input to the control device 19.

As shown in FIGS. 5 and 7, in the swivel 2, the backhoe device 3 is disposed on the right side, and the driver's seat 28 and the driving unit 27 including the right and left operation levers 9, 10 are disposed on the left side. Have been. A vertical partition plate 29 with a window that partitions the backhoe device 3 and the operation unit 27 is provided at the left and right center of the revolving base 2, and has a semicircular shape along the outside of the revolving platform 2 at the upper end of the vertical partition plate 29. Upper partition plate 30
Has been fixed.

As shown in FIGS. 2, 4 and 5, in a range above a predetermined position D which is at a predetermined height from the ground G, a first restraining surface A which is separated from the upper partition plate 30 by a predetermined distance.
1. The second restraint surface A2, which is separated by a predetermined distance forward (outward) from the vertical partition plate 29, and the second restraint surface A2, which is separated from the side surface of the vertical partition plate 29 on the backhoe apparatus 3 side by a predetermined distance to the right (outward). The three check surfaces A3 are set in the control device 19.

In this case, as shown in FIG. 2, when the bucket pin 6a connecting the bucket 6 to the tip of the arm 5 is located on the first and second restraining surfaces A1 and A2, the bucket 6 is moved most to the operating portion. The first and second restraint surfaces A1 and A2 are set such that the tip of the bucket 6 is located on a locus C1 separated by a predetermined distance from the vertical and upper partition plates 29 and 30 even if the operation is performed so as to approach the 27th side. Have been. In a state where the bucket pin 6a is on the third check surface A3 as shown in FIG. 5, the third check surface is set such that the lateral side surface of the bucket 6 is on the locus C2 separated from the vertical partition plate 29 by a predetermined distance. A3 is set. A surface which is outwardly separated from the first, second, third restraint surfaces A1, A2, A3 by a predetermined distance is set, and a space between this space and the first, second, third restraint surfaces A1, A2, A3 is It is set in the control device 19 as the restraint area B.

When excavating the ground G by the backhoe device 3, the backhoe device 3 determines how close the backhoe device 3 can excavate to the traveling device 1 side.
Its own mechanical operating limits are determined in advance. It is calculated which trajectory the bucket pin 6a passes when operated to the operation limit. The trajectory having a margin (outside) slightly from the trajectory of the bucket pin 6a corresponding to the operation limit is defined by the first, second, and third boundaries. As surfaces E1, E2, and E3, as shown in FIGS. 2 and 4, in a range below the predetermined position D, a first boundary surface E in front of the traveling device 1 on the left side (the driving unit 27 side).
1, a central second boundary surface E2, and a third boundary surface E3 in front of the traveling device 1 on the right side (the backhoe device 3 side) are set in the control device 19. First, second, third boundary surfaces E1, E
2 and E3 are set so as to be smoothly connected to the second restraining surface A2, and when the bucket pin 6a is at the first, second, and third boundary surfaces E1, E2, and E3, the bucket 6 is most connected to the traveling device 1. When operated so as to approach, the tip of the bucket 6 passes along the locus C3. The first, second, and third check surfaces A1, A2, and A3, the check region B, and the first, second, and third boundary surfaces E1, E2, and E3 are set with respect to the turntable 2. As the turntable 2 turns, it moves together with the turntable 2.

Next, the first, second, and third check surfaces A1, A2, A
3. Control of the backhoe device 3 for the restraint area B will be described. As shown in FIGS. 1 and 2, in the control device 19, the vertical angle of the boom 4 (the first boom portion 4 a), the horizontal angle of the second boom portion 4 b, and the front and rear of the arm 5 based on the detection signals of the potentiometers 36, 37, 38. The position of the bucket pin 6a (corresponding to the telescopic positions of the hydraulic cylinders 11, 12, 7) is always calculated from the angle and the lengths of the first boom portion 4a, the second boom portion 4b, and the arm 5 (step). S1). If the height of the bucket pin 6a is equal to or higher than the predetermined position D (step S2) and the bucket pin 6a is not located in the restraint area B (step S3), the right and left operation levers 9, 10 and the operation pedal 2
The hydraulic cylinder 1 at the expansion / contraction speed based on the operation position 6
1, 12, and 7 are extended and contracted as usual.

When the bucket pin 6a is located in the restraining area B (step S3) (the state shown in FIG. 3 is a state where the bucket pin 6a is located in the restraining area B of the second restraining surface A2). As shown in FIGS. 1 and 3, the detection values of the potentiometers 36, 37, 38 are differentiated, and the current moving direction and moving speed of the bucket pin 6a are calculated as the speed vector V1 or V2 (step S4) (step S4). (Corresponds to the direction and speed of expansion and contraction of the hydraulic cylinders 11, 12, 7). Current position and velocity vector V of bucket pin 6a
1 or V2, the moving distance L1 or L2 from the current position of the bucket pin 6a to the first, second, and third tread surfaces A1, A2, and A3 is calculated (step S5), and the moving distance L1 is calculated.
Or, when the bucket pin 6a moves at a constant speed in which the current speed vector V1 or V2 remains at L2, the bucket pin 6a reaches the first, second, and third check surfaces A1, A2, and A3 from the current position. The estimated time T1 or T2 up to is calculated (step S6).

As described above, when the current position of the bucket pin 6a, the velocity vector V1 or V2, and the predicted time T1 or T2 until the bucket pin 6a reaches the first, second, and third check surfaces A1, A2, and A3 are obtained. 6. Pilot valves 31a and 31 shown in FIG.
The pilot pressures of b, 32a, 32b, 35a, and 35b are reduced, and the opening degrees of the control valves 21, 22, and 25 are reduced.
The expansion and contraction speed of the hydraulic cylinders 11, 12, and 7 is decelerated so that the predicted time T1 or T2 becomes the set time (step S7). The set time is the first, second and third check surfaces A1, A
2 and A3 are continuously set by the shortest distance in the horizontal direction with respect to A3, and the first, second, and third check surfaces A1, A2,
It becomes shorter as it approaches A3.

Thus, when the bucket pin 6a is in the state of the velocity vector V1 as shown in FIG. 3, the moving distance L1 and the predicted time T1 until the bucket pin 6a reaches the second braking surface A2 are relatively short. Bucket pin 6a is second
The hydraulic cylinder 1 can reach the check surface A2 relatively quickly.
The deceleration rate of the expansion / contraction speed of 1, 12, 7 is large.
Conversely, if the bucket pin 6a is in the state of the velocity vector V2, the moving distance L2 and the predicted time T2 until the bucket pin 6a reaches the second restraint surface A2 are relatively long, and the bucket pin 6a is in the second restraint surface A2. Because it reaches relatively late
The deceleration rate of the expansion / contraction speed of the hydraulic cylinders 11, 12, 7 is small.

In the restraint area B, the current position of the bucket pin 6a and the speed vector V1 or V
2. By constantly calculating the predicted time T1 or T2 until the first, second, and third check surfaces A1, A2, and A3 are reached, the bucket pin 6a moves horizontally, diagonally upward, or diagonally downward at the position of the bucket pin 6a. Regardless of the movement, regardless of this, the bucket pin 6a is set for the set time (first, second, third,
The shorter the closer to the check surfaces A1, A2, A3),
The hydraulic cylinders 11, 12, and 7 are decelerated so as to reach the check surfaces A1, A2, and A3. This allows
The more the bucket pin 6a enters the restraint area B, that is, the more the bucket pin 6a moves to the first, second, and third restraint surfaces A1, A2, A
As the position approaches 3, the hydraulic cylinders 11, 12, 7 expand and contract at a lower speed.

The bucket pin 6a is connected to the first, second, and third check surfaces A
When the backhoe device 3 is operated in a direction in which the bucket pin 6a moves away from the first, second, and third restraint surfaces A1, A2, and A3 in a state where the backhoe device 3 is located at positions 1, 1, 2 and A3, the reverse check is performed in reverse to the above-described deceleration operation. The hydraulic cylinders 11, 12,
The expansion / contraction speed of 7 is increased, and returns to the normal expansion / contraction speed when the vehicle comes out of the restraint area B.

Conversely, when the bucket pin 6a is about to be operated toward the operation section 27 slightly beyond the first, second and third restraint surfaces A1, A2 and A3 (step S8), the pilot valves 31a to 32b and 35a are operated. , 35b disappears and the control valves 21, 22, 25 control the hydraulic cylinder 1
Stop operations of 1, 12, and 7 are performed (step S9). When the bucket pin 6a is located at the first, second, third restraint surfaces A1, A2, A3, the hydraulic cylinder 13 of the bucket 6 can be expanded and contracted.
The operation of moving the check surfaces A1, A2, A3 can also be performed at an extremely low speed.

As described above, the restraint area B is set in the portion above the predetermined position D shown in FIG. 2, but such a restraint area B is not set in the portion below the predetermined position D. . Therefore, in the portion below the predetermined position D, the process proceeds from step S2 to step S8, and the right and left operation levers 9, 10 are maintained until the bucket pin 6a reaches the first, second, third boundary surfaces E1, E2, E3. , Operation pedal 26
The hydraulic cylinders 11, 1
2, 7 expand and contract. Even if the bucket pin 6a is a little
2, 3 boundary surface E1, E2, E3 (first, second, third check surface A
1, A2, A3), the pilot valve 31a to 32b, 35a, 3
5b, the pilot pressure disappears and the control valves 21, 22, 25
As a result, the hydraulic cylinders 11, 12, 7 are stopped.

The bucket pin 6a is connected to the first, second, and third boundary surfaces E.
1, E2, and E3, the hydraulic cylinder 13 of the bucket 6 can be extended and retracted.
An operation such that a moves on the first, second, and third boundary surfaces E1, E2, and E3 can also be performed. Thus, when the bucket 6 scrapes the soil on the ground G near the traveling device 1, the bucket pin 6a moves upward along the first, second, and third boundary surfaces E1, E2, and E3. You just need to lift it. By doing so, the bucket pins 6a are moved to the first, second, third
The transition from the boundary surfaces E1, E2, E3 to the second restraint surface A2 smoothly enters the restraint region B, where the hydraulic cylinders 11, 1
2, 7 are decelerated as described above.

In this backhoe, as shown in FIGS. 2, 4, and 5, there are six first, second, and third check surfaces A1, A2, and A3, and first, second, and third boundary surfaces E1, E2, and E3. Each of the six surfaces can be selected to be erased or regenerated, and a selection switch 39 (push-on push-off type) (see FIG. 6) is provided in the driving unit 27.

Accordingly, by operating the selection switch 39, the first, second and third restraint surfaces A1, A2 and A3 and the first and second and third boundary surfaces E1, E2 and E3 are selected according to the state of work. A required surface can be selected to be generated or deleted, and the first, second, and third check surfaces A1, A
A monitor 40 is provided for displaying the generated surface of the second, third, and third boundary surfaces E1, E2, and E3 by lighting a lamp. When the engine (not shown) is once stopped and restarted, the first, second, and third check surfaces A
1, A2, A3 and first, second, third boundary surfaces E1, E2, E
3 is returned to the state where it occurs.

In this backhoe, the swivel range of the swivel base 2 can be stored. When the swivel base 2 is turned by operating the left operating lever 10 right and left, the swivel base 2 stores the swivel range. When the end of the swivel range is reached, the swivel 2 is automatically stopped. In this case, FIG.
As shown in the figure, the control valve 24 and the pilot valve 34 of the swivel 2
A two-position switching type electromagnetically operated unload valve 41 is provided between the turntable 2 and the a and b. When the end of the swivel range stored by the swivel base 2 is reached, the unload valve 41 is moved to the unload position. By operating the control valve 24 to return to the neutral position, the swivel 2 is stopped. Unload valve 4
1 is provided with an electromagnetic proportional valve (not shown),
When reaches near the end of the turning range, the pilot pressure is suppressed by the electromagnetic proportional valve and the opening of the control valve 24 is suppressed, so that the turntable 2 is stopped at the end of the turning range while decelerating. You may.

[Alternative Embodiment] In the above-described embodiment, the position, the moving direction and the moving speed of the bucket pin 6a are calculated based on the detection signals of the potentiometers 36, 37 and 38, and the expanding and contracting positions of the hydraulic cylinders 11, 12, and 7 are calculated. , The direction of expansion and contraction and the expansion and contraction speed, and the bucket pin 6a is
1, A2, A3, when the hydraulic cylinders 11, 12,
7 is operated to stop, but it may be configured as follows. Focusing on one hydraulic cylinder for driving the backhoe device 3, a position sensor for detecting the position of the piston of the hydraulic cylinder is provided. At the position where the piston of the hydraulic cylinder approaches the stroke end (corresponding to the set expansion / contraction position) and slightly before reaching the stroke end, the expansion / contraction speed of the piston is calculated by differentiating the detection value of the position sensor.

Accordingly, when the distance between the piston and the stroke end is longer than the set value and the expansion / contraction speed at which the piston approaches the stroke end is higher than the set value, the expansion / contraction speed of the piston is maintained. If the distance between the piston and the stroke end is longer than the setting and the expansion / contraction speed at which the piston approaches the stroke end is lower than the setting, the expansion / contraction speed of the piston is slightly increased. Conversely, if the distance between the piston and the stroke end approaches the setting or less and the expansion / contraction speed at which the piston approaches the stroke end is faster than the setting, the expansion / contraction speed of the piston is reduced. When the distance between the piston and the stroke end approaches the setting end or less and the expansion / contraction speed at which the piston approaches the stroke end is lower than the setting, the expansion / contraction speed of the piston is maintained as it is.

In the above-described embodiment , FIGS.
As shown in FIG. 5 , the first, second, and third check surfaces A1, A2, and A3 are set on the basis of the position of the bucket pin 6a, but a potentiometer (not shown) is installed at the position of the bucket pin 6a. Alternatively, the control device 19 may always calculate the position of the tip of the bucket 6. In this case, the trajectories C1 and C2 shown in FIGS.
It becomes a check surface.

Incidentally, reference numerals are written in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a diagram showing a control flow in first, second, and third check surfaces and check regions.

FIG. 2 shows first and second check surfaces, check areas and first, second, and second check surfaces.
Schematic side view of backhoe showing three boundary surfaces

FIG. 3 is a side view showing a moving state of a bucket within a check area of a second check surface.

FIG. 4 is a schematic front view of the backhoe showing the first, second and third restraint surfaces and the first, second and third boundary surfaces.

FIG. 5 is a schematic plan view of a backhoe showing second and third check surfaces and a check area;

FIG. 6 is a diagram showing a relationship between a hydraulic cylinder, a control valve, a pilot valve, right and left operation levers, and the like of the backhoe device.

FIG. 7 is an overall side view of the backhoe.

[Explanation of Signs] 2 Swivel 3
Backhoe device 6 bucket 1
1,12,7 hydraulic cylinders 21, 22, 25 control valve 27 driving unit 29, 30 outside off
Frames 36, 37, 38 Position sensors A1, A2
Checking surface B Checking area

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E02F 3/43 E02F 9/20 E02F 9/24

Claims (1)

(57) [Claims] 1. A hydraulic cylinder (11) for driving a backhoe device (3) provided on a swivel (2).
2) and (7) position sensors (3)
6), (37), and (38), and the hydraulic cylinders (11), (12), and (12) based on the detection values of the position sensors (36), (37), and (38).
When (7) reaches the set telescopic position, the control valves (21), (22) and (25) for supplying and discharging the hydraulic oil to the hydraulic cylinders (11), (12) and (7) are set to the neutral position. Return the hydraulic cylinders (11), (12), (7)
A stop means for stopping the hydraulic cylinder at the set telescopic position, a detecting means for detecting the telescopic direction and the telescopic speed of the hydraulic cylinders (11), (12), (7); and the hydraulic cylinders (11), ( 12), (7) in a state where is close to the set stretch position, the hydraulic cylinder (11), (12), (distance 7) and the set stretch position location is small, the hydraulic cylinder (11), (12), (7)
The larger the expansion / contraction speed of the hydraulic cylinder (11),
(12), (7) is provided with deceleration means for decelerating the hydraulic cylinders (11), (12), (7) by suppressing the flow rate of the hydraulic oil supplied / discharged , and further comprises the turning table ( Of the driving unit (27) provided in 2)
Outside from the outer frames (29) and (30) covering the outermost
The check surfaces (A1) and (A2) separated by a predetermined distance
And a first setting means for setting a predetermined distance outward from the check surfaces (A1) and (A2).
Between the surface of the distant space and the check surfaces (A1) and (A2)
Setting means for setting the restraint area (B) in the position sensors (36), (37), (38) and the front
The backhoe device based on the detection value of the
(3) The position of the bucket (6) and the bucket (6)
Of the moving direction of the bucket and the moving speed of the bucket (6) are calculated.
And the bucket (6) is positioned within the restraint area (B).
In this state, the bucket (6) is
From the position in the area (B) to the check surfaces (A1) and (A2)
When calculating the travel distance taking into account the travel direction until it reaches
In both cases, the bucket (6) has the current check
From the position in the area (B2), the check surfaces (A1), (A
And 2) calculating means for calculating an estimated time to reach 2).
The deceleration means determines that the moving direction of the bucket (6) is
It is the direction in which the movement component to the check surfaces (A1) and (A2) is large.
Therefore, the shorter the predicted time, the more the hydraulic cylinder (1
1), (12), (7) Flow rate of hydraulic oil supplied / discharged
The hydraulic cylinders (11), (12), (7)
Hydraulic cylinder stop structure of the backhoe configured to decelerate the wheel.