JPH08158413A - Backhoe - Google Patents

Abstract

PURPOSE: To heighten the safety in operation by furnishing the cab with a sensor to find whether an operator exists or not and a warning means. CONSTITUTION: Restraining surfaces A1, A3 are set a certain distance apart outward from external frames 29, 30 enclosing a cab 27 furnished on a revolving table 2, and on the basis of sensing result from a position sensor which senses the position of a bucket 6, a restraining means stops and checks a hydraulic cylinder of a backhoe device 3 when the bucket 6 goes beyond the surfaces A1, A3 and intrudes to the cab 27 side. A changeover means changes over manually the restraining means into the operating condition and the stop condition. If the operater is substituted in the condition that the restraining means is stopped by the changeover means during the engine being in operation, an operator presence sensor 45 is changed over into the condition to sense operator, and a warning means is actuated. The operator acknowledges that the restraining means is in the stop condition and manipulates the backhoe device 3 carefully so that the safety in operations is heightened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backhoe structure for avoiding contact between an outer frame covering a driving part and a bucket of a backhoe device.

[0002]

2. Description of the Related Art In the backhoe described above, an example of a structure for avoiding contact between an external frame and a bucket is disclosed in Japanese Patent Laid-Open No. 4-333730. In this structure, a check surface (A1 in FIGS. 1 and 2 of the publications described above, which is separated from the external frame (29, 30 in FIGS. 1 and 2 of the publications) of the publication by a predetermined distance, is provided. A2) is set in the space and a position sensor (36, 37, 3 in FIG. 5 of the above publication is used to detect the position of the bucket of the backhoe device.
8) is provided, and when the bucket reaches the check surface and tries to enter the operation section side beyond the check surface, the control valve for the backhoe device is operated to the neutral stop position to stop the hydraulic cylinder and prevent the check. Equipped with restraint means. As a result, when the operator of the driving section is operating the backhoe, even if the operator accidentally moves the bucket closer to the driving section, the bucket will reach the check surface outside the outer frame. In this case, the bucket (hydraulic cylinder) automatically stops and contact is avoided.

The above-mentioned backhoe is provided with a switching means capable of artificially selectively switching the restraining means between an operating state and a stopped state, and when the bucket is desired to be operated toward the driving section especially beyond the restraining surface, the switching is performed. The backhoe device is operated by switching the means (checking means) to the stopped state. In this case, in order to notify the operator of the operating unit that the restraint means is in the stopped state, the alarm lamp is turned on when the switching means (checker means) is switched to the stopped state.

[0004]

In the above-mentioned backhoe, when the switching means (checking means) is switched to the stopped state, the operator who has switched the switching means can operate the backhoe device without leaving the operating part. If so, this worker rarely forgets that the switching means (checking means) is in a stopped state.

However, when one operator switches the switching means (checking means) to a stopped state and then gets out of the operating section and another operator tries to operate the backhoe device by getting into the operating section of this backhoe, If you overlook the lit warning lamp, you will operate the backhoe without noticing that the restraint means is in a stopped state, so you could accidentally move the bucket to the external frame by another operator. May cause contact. The present invention, in the backhoe provided with a restraint means for avoiding contact between the outer frame of the operating unit and the bucket, particularly when the operator changes after switching the restraint means to a stopped state,
The purpose is to prevent a situation in which another worker accidentally brings the bucket into contact with the external frame.

[0006]

A feature of the present invention is that the backhoe as described above is configured as follows. That is, [1] a setting means for setting a check surface in a space that is outwardly separated by a predetermined distance from an external frame that covers the driving part provided on the swivel base, and a position sensor that detects the position of the bucket of the backhoe device. When the bucket tries to enter the operation unit side beyond the restraint surface based on the detection of the position sensor, the restraint means is provided to stop the hydraulic cylinder for driving operation of the backhoe device to restrain the restraint. In addition to the switching means capable of artificially selecting and switching between the operating state and the stopped state, the presence / absence sensor for detecting whether or not there is an operator in the driving section and the warning means are provided, and the engine is operating and the switching means is provided. When the switch is operated to switch to the stopped state, the presence / absence sensor switches from a state in which it detects a worker to a state in which it does not detect it, and then switches to a state in which it detects a worker again. In other words, the control means for activating the warning means is provided.

[2] Setting means for setting a check surface in a space, which is separated by a predetermined distance outward from an external frame that covers the operating part provided on the swivel base, and a position sensor for detecting the position of the bucket of the backhoe device. When the bucket tries to enter the operation unit side beyond the restraint surface based on the detection of the position sensor, the restraint means is provided to stop the hydraulic cylinder for driving operation of the backhoe device to restrain the restraint. Is equipped with a switching means that can be selectively switched between an operating state and a stopped state, and a presence / absence sensor that detects whether or not there is an operator in the operating unit, so that the engine is operating and the switching means is in a stopped state. In the state where the switching operation is performed, the presence / absence sensor switches from a state in which the worker is detected to a state in which the worker is not detected, and a state in which the worker is detected again, The switch means are provided with control means for automatically switching operation to the operating state from the stopped state.

[0008]

[Action]

[I] According to the configuration described in [1] above, in the state in which the operator in the driving section operates the switching means to the stop state by the switching means while the engine is operating, the operator leaves the driving section, When an operator or another operator gets into the driving part, the warning means is activated. In this way, when the worker activates the warning means when getting into the driving section, the worker does not have to know the previous state of the backhoe (whether the restraint means is in the operating state or in the stopped state) (forget it). However, the operator can recognize that the backhoe restraint means is in a stopped state. Therefore, after the operator gets in the vehicle, the operator may operate the backhoe device carefully while recognizing the stop state of the restraint means, or switch the switch means (check restraint means) to the operating state before starting the operation of the backhoe device. Good.

[II] When configured as in the above item [2],
While the engine is in operation, in the state where the operator in the driving section switches the restraint means to the stopped state by the switching means, this operator leaves the driving section and this worker or another worker gets into the driving section. Then, the switching means (checking means) is automatically switched to the operating state. If the operator automatically switches the switching means (checking means) to the operating state when the operator gets into the driving section in this way, the operator can keep the previous backhoe state (the checking means is in the operating state). Whether the operator operates the backhoe device without knowing whether the bucket is in a stopped state or not), the bucket does not come into contact with the external frame due to the action of the restraining means.

[0010]

According to the first aspect of the present invention, in the backhoe provided with the restraint means for avoiding the contact between the outer frame of the driving section and the bucket, the switching means by the warning means when the operator gets into the driving section. Since the operator can recognize that the (checking means) is in the stopped state, the operator operates the backhoe device without knowing (forgetting) that the switching means (checking means) is in the stopped state, It was possible to prevent the situation where the bucket was brought into contact with the external frame, and it was possible to improve the workability of the backhoe.

According to the second aspect of the invention, in the backhoe provided with the restraint means for avoiding the contact between the outer frame of the driving section and the bucket, the switching means (checking means) is automatically operated when the operator gets in the driving section. Since the operation is switched to the operating state, the operator may operate the backhoe device and bring the bucket into contact with the external frame without knowing (forgetting) that the switching unit (checking unit) is in the stopped state. This situation was prevented and the workability of the backhoe could be improved.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. (1) FIG. 1 shows the entire side surface of a backhoe, in which a dozer 20 and a swivel base 2 are supported by a traveling device 1 of a rubber crawler type, and a backhoe device 3 is provided in a front part of the swivel base 2. The backhoe device 3 includes a boom 4 that is rockably driven by a hydraulic cylinder 11, an arm 5 that is rockably driven by a hydraulic cylinder 12, and a bucket 6 that is rockably driven by a hydraulic cylinder 13. A hydraulic motor 14 is provided to drive the swivel base 2.

As shown in FIG. 1, the boom 4 of the backhoe device 3 includes a first boom portion 4a connected to a swivel base 2 so as to be vertically swingable, and right and left around an axis P1 at the front end of the first boom portion 4a. A second boom portion 4b swingably connected to the
The support bracket 4c is swingably connected to the left and right around the axis P2 at the front end of the second boom portion 4b, and the arm 5 is connected to the support bracket 4c.
The linkage link 8 is laid across the first boom portion 4a and the support bracket 4c to form a parallel four-link.
By swinging the second boom portion 4b with the hydraulic cylinder 7, the arm 5 and the bucket 6 are moved in parallel to the left and right.

As shown in FIG. 5, the control valve 21 for the hydraulic cylinder 11 of the first boom portion 4a of the boom 4,
Hydraulic cylinder 7 of second boom portion 4b of boom 4
A control valve 25 for the hydraulic cylinder 12 of the arm 5, a control valve 23 for the hydraulic cylinder 13 of the bucket 6, and a control valve 24 for the hydraulic motor 14 of the swivel base 2. The control valves 21 to 25 are of three-position switching type and pilot operated type, and the flow rate can be controlled by adjusting the opening degree based on the pilot pressure. An electromagnetic proportional pressure reducing valve type pilot valve 31, 32, 3 for supplying a pilot pressure for operating the opening to each control valve 21-25
3, 34, 35 are provided.

As shown in FIGS. 5 and 4, the swivel base 2 is provided with a right operation lever 9 and a left operation lever 10.
The right and left operation levers 9 and 10 can be operated forward, backward, left and right, and are provided with a potentiometer 15 for detecting the operation position of the right operation lever 9 in the front-rear direction and a potentiometer 16 for detecting the operation position in the left-right direction. A potentiometer 17 for detecting an operation position in the front-rear direction of 10 and a potentiometer 18 for detecting an operation position in the left-right direction are provided, and operation signals from the potentiometers 15 to 18 are input to the control device 19. An operation pedal 26 is provided on the lower front side of the swivel base 2, and an operation signal from the operation pedal 26 is input to the control device 19.

With the above construction, when the right operation lever 9 is operated forward or backward, an operating current is supplied from the control device 19 to the pilot valve 31 on the basis of this and the pilot valve 31 is operated, so that the control valve 21 is moved to the first boom. When the portion 4a is operated to the descending side or the ascending side, and when it is operated to the right or left, the pilot valve 33 is operated based on this, and the control valve 23 is operated to the soil discharging side or the scraping side of the bucket 6. When the left operation lever 10 is operated forward or backward, an operation current is supplied from the control device 19 to the pilot valve 32 based on this, and the pilot valve 32 is operated, so that the control valve 22 is operated to the raising side or the scraping side of the arm 5. When operated to the right or left, the pilot valve 34 is operated based on this, and the control valve 2
4 is operated to the right turning side or the left turning side. When the operation pedal 26 is stepped to the right or left, an operating current is supplied from the control device 19 to the pilot valve 35 based on this, and the pilot valve 35 is operated, so that the control valve 25 moves to the right or to the second boom portion 4b. It is operated to the left swing side.

In the above operation, the potentiometers 15 to 18 for the right and left operation levers 9 and 10 detect not only the operation direction of the right and left operation levers 9 and 10 but also the operation amount from the neutral position thereof. There is. As a result, as the operation amount of the right and left operation levers 9 and 10 increases, the pilot pressure of the pilot valves 31 to 34 increases and the control valves 21 to 2 increase.
4 is operated to the high flow rate side. That is, the larger the right and left operating levers 9 and 10 are operated, the more hydraulic cylinders 11 to 1 are operated.
3 and the hydraulic motor 14 are configured to operate at high speed.

(2) Next, the front first and second front restraint surfaces A1 and A2 and the horizontal restraint surface A3 set for the operating portion 27 of the swivel base 2 will be described. As shown in FIGS. 2, 3 and 4, in the swivel base 2, the backhoe device 3 is arranged on the right side, and the driver's seat 28 and the driver 27 composed of the right and left operating levers 9 and 10 are arranged on the left side. There is. A partition wall 29 (corresponding to an external frame) with a window for partitioning the backhoe device 3 and the operation unit 27 is provided at the center of the swivel base 2 on the left and right, and the upper end of the partition wall 29 extends along the outside of the swivel base 2. A semi-circular roof portion 30 (corresponding to an external frame) is fixed.

As shown in FIGS. 1 and 5, a potentiometer 36 (corresponding to a position sensor) for detecting the vertical angle of the first boom portion 4a (boom 4) with respect to the swivel base 2, and a second boom for the first boom portion 4a. A potentiometer 37 (corresponding to a position sensor) that detects the left / right angle of the portion 4b, a potentiometer 38 (corresponding to a position sensor) that detects the longitudinal angle of the arm 5 with respect to the support bracket 4c, and a longitudinal angle of the bucket 6 with respect to the arm 5 are detected. A potentiometer 39 (corresponding to a position sensor) is provided, and the detection values of the potentiometers 36 to 39 are input to the control device 19.

As shown in FIGS. 2, 3 and 4, the partition wall 29 is located in a range above a predetermined position D above the swivel base 2.
The front first check surface A1 (corresponding to the check surface) having a predetermined left and right width apart from the front edge 29a of the front side of the front side by a predetermined distance is set in the space (corresponding to the setting means), Front second with a predetermined vertical width separated by a predetermined distance
The restraint surface A2 (corresponding to the restraint surface) is set in the space in series with the front first restraint surface A1 (corresponding to a setting unit). In a range above the predetermined position D, a surface which is separated from the front first and second front check surfaces A1 and A2 by a predetermined distance is set, and the surface of the space and the front first and second check surfaces A1 are set. , A2
Between the front first check area B1 and the second front check area B2.
Is set as

A flat lateral check surface A3 (on the check surface) is separated from the end of the front first check surface A1 on the backhoe device 3 side to the rear by a predetermined distance from the partition wall 29 to the right in the drawing. (Corresponding to the setting means) is set in the space.
A surface separated from the lateral restraint surface A3 by a predetermined distance to the right side of the paper surface of FIG. 4 is set, and a space between the surface of this space and the lateral restraint surface A3 is set as a lateral restraint area B3. The front first and front second check surfaces A1 and A2, the front first and front second check areas B1 and B2, the horizontal check surface A3, and the horizontal check area B as described above.
3 is set in the space of the swivel base 2 and moves with the swivel base 2 as the swivel base 2 turns.

(3) Next, the predetermined position D in FIGS. 2 and 3 will be described. As shown in FIG. 2, the second boom portion 4b is operated by the hydraulic cylinder 7 so that the bucket 6 is located in front of the front edge 29a of the partition wall 29, and the arm 5 is scraped to the end of the operating range. The bucket 6 is operated to the dumping side, and the tip of the bucket 6 and the arm 5 are operated.
In a state in which and are operated so as to form a straight line (the state in which the length from the arm 5 to the tip of the bucket 6 is the longest),
When the first boom portion 4a is operated upward, the bucket 6
The tip of is moving on the locus C.

In this case, the first boom portion 4 is in the above-mentioned state.
The position where the tip of the bucket 6 comes closest to the front edge 29a of the partition wall 29 when the a is operated to the upside is the predetermined position D, and the first boom portion 4a is crossed beyond the predetermined position D.
Is operated to the upside, the tip of the bucket 6 is moved to the partition wall 29.
The front edge 29a of the. On the contrary, even if the first boom portion 4a is operated to the descending side from the predetermined position D in the above-mentioned state, the tip of the bucket 6 does not contact the front edge 29a of the partition wall 29 and the swivel base 2.

(4) Next, the front first and second check surfaces A
1, A2, front first and second front restraint areas B1, B2 control of the backhoe device 3 will be described. In the control device 19, the vertical angle of the first boom portion 4a, the horizontal angle of the second boom portion 4b, the front-back angle of the arm 5 and the bucket 6, and the front and rear angles of the first boom portion 4a and the second boom portion 4a, which are detected by the potentiometers 36 to 39. The position of the tip of the bucket 6 is constantly detected by the lengths of the boom portion 4b, the arm 5, and the bucket 6, and the potentiometers 36 to 3 are used.
The moving direction and moving speed of the tip of the bucket 6 are detected by differentiating the detected value of 9.

When the tip of the bucket 6 is located in front of the front edges 29a, 30a of the partition wall 29 and the roof portion 30, the tip of the bucket 6 is located at the front first and second front portions of FIGS. When entering the restraint regions B1 and B2, regardless of the operation of the right and left operation levers 9 and 10 and the operation pedal 26,
From the control device 19 to the pilot valves 31, 32, 33, 35
The operating current to the control valve 21,
22, 23, 25 are operated to the neutral stop position side, and the operating speed of the hydraulic cylinders 7, 11, 12, 13 (bucket 6) is decelerated.

In this case, as the tip of the bucket 6 is closer to the front first and second check surfaces A1 and A2 in the front first and second check areas B1 and B2, the pilot valve 3
The operating currents to 1, 32, 33, 35 are continuously reduced, and the hydraulic cylinders 7, 11, 12, 13 (bucket 6)
The operating speed of is continuously decelerated. Conversely, when the first boom portion 4a or the like is operated in the direction in which the tip of the bucket 6 moves away from the front first and second front restraining surfaces A1 and A2 in the front first and second front restraining areas B1 and B2. Is the reverse of the deceleration operation described above, the hydraulic cylinders 7, 11, 12, 13
The operating speed of the (bucket 6) is increased, and then returns to the original operating speed when it exits from the front first and second front restraint regions B1 and B2.

Next, the tip of the bucket 6 is moved to the front first restraining surface A.
It is assumed that 1 or the previous second restraint surface A2 is reached. In this case, the pilot valves 31, 32, 33, 35 may be operated even if the bucket 6 is operated beyond the front first or second check surfaces A1, A2 such as the operation of the arm 5 on the scraping side. Control current to the control valve 2
1, 22, 23, 25 are operated to the neutral stop position, and the hydraulic cylinders 7, 11, 12, 13 (bucket 6) are stopped (the above is equivalent to the restraining means). On the contrary, when the tip of the bucket 6 reaches the front first or second front restraining surfaces A1 and A2, the tip of the bucket 6 moves to the front first or front second restraint, such as when the arm 5 is operated toward the raising side. The operation away from the surfaces A1 and A2 can be performed without any trouble.

The tip of the bucket 6 is the front edge 2 of the partition wall 29.
When the second boom portion 4b is operated by the hydraulic cylinder 7 to the left side (the driving unit 27 side) around the axis P1 of the first boom portion 4a in the state of being located in front of 9a,
If the tip of the bucket 6 does not touch the front first check surface A1,
The second boom portion 4b can be operated to the left side (driving section 27 side). This is because the side of the front first restraint surface A1 on the side of the operation unit 27 is a space where there is nothing that the tip of the bucket 6 contacts. Then, in the vicinity of the lower end of the front first restraint surface A1 (near the predetermined position D), the second boom portion 4
When b is operated to the left side (driving section 27 side), the bucket 6
3 has a tip end of a guard frame 40 of the driving unit 27 (which is connected across the middle of the front edge 29a of the partition wall 29 and the swivel base 2) shown in FIGS. 3 and 4, and an operating lever 41 for the traveling device 1. Guard frame 4 to prevent contact with
The positions of 0 and the operation lever 41 are set.

(5) Next, as shown in FIG.
In the state where the tip of is located below the predetermined position D,
As described above, when the bucket 6 is positioned in front of the front edge 29a of the partition wall 29, the tip of the bucket 6 moves on the locus C when the first boom portion 4a is operated up and down. The tip of the bucket 6 does not contact the front edge 29a of the partition wall 29 and the swivel base 2.

Even if the hydraulic cylinder 7 operates the second boom portion 4b to the left or right while the tip of the bucket 6 is located below the predetermined position D and located on the locus C,
The tip of the bucket 6 does not come into contact with the swivel base 2, the guard frame 40 of the driving unit 27, the operation lever 41 for the traveling device 1, or the like. As described above, at the position below the predetermined position D, the tip of the bucket 6 is moved so that the tip of the bucket 6 does not come into contact with the swivel base 2 and the like, no matter how the backhoe device 3 is operated. Since the locus is set, the front first and front second check surfaces A1 and A2, the front first and front second check areas B1 and B2, etc. as shown in FIGS. 2, 3, and 4 are not set.

(6) Next, the control of the backhoe device 3 with respect to the lateral restraint surface A3 and the lateral restraint area B3 will be described. In the control device 19, similarly to the above, the vertical angle of the first boom portion 4a based on the detection values of the potentiometers 36 to 39, the horizontal angle of the second boom portion 4b, the longitudinal angle of the arm 5 and the bucket 6, and the first boom portion 4a. , The length of the second boom portion 4b, the arm 5 and the bucket 6,
The position of the left lateral surface of the bucket 6 is constantly detected, and the moving direction and the moving speed of the left lateral surface of the bucket 6 are detected by differentiating the detection values of the potentiometers 36 to 39.

As shown in FIGS. 3 and 4, when the bucket 6 is positioned on the right side of the operating unit 27, the second boom portion 4b is operated to the operating unit 27 side by the hydraulic cylinder 7 and the bucket 6 is moved. When the left lateral surface of the second side enters the lateral restraint region B3, the operation current to the pilot valve 35 is reduced by the control device 19 as in the case of the above (4), and the second boom is irrespective of the operation of the operation pedal 26. The operating speed of the hydraulic cylinder 7 (bucket 6) of the portion 4b is decelerated.
In this case, as the left lateral side surface of the bucket 6 enters the lateral restraint area B3 and approaches the lateral restraint surface A3, the deceleration operation is greatly performed. On the contrary, when the second boom portion 4b is operated in the direction in which the left lateral side surface of the bucket 6 is separated from the lateral restraint surface A3, the second boom portion 4b is moved within the lateral restraint area B3 contrary to the deceleration operation described above. The operating speed of the hydraulic cylinder 7 is increased, and returns to the original operating speed when it comes out of the lateral restraint region B3.

Next, the left lateral surface of the bucket 6 is a lateral restraint surface A.
When it reaches 3 and is about to be operated toward the operation part 27 side beyond the lateral restraint surface A3, the operating current to the pilot valve 35 becomes zero and the pilot pressure becomes equal to the pilot pressure as in the case of the above (4). After that, the control valve 25 causes the hydraulic cylinder 7 (bucket 6) of the second boom portion 4b to be stopped (the above is equivalent to the restraining means).

(7) In this backhoe, the front first and second restraint surfaces A1, described in (4) and (6) above, are used.
A2, lateral restraint surface A3, hydraulic cylinders 7, 11, 12, 1
3 (bucket 6) stop operation is performed and a state in which the stop operation is not performed, the changeover switch 42 that can be manually switched.
(Corresponding to a switching unit), and the control based on the changeover switch 42 will be described below with reference to FIG.

As shown in FIG. 5, the operating section 27 is provided with a push button type changeover switch 42, and the changeover switch 42 is turned on while the engine (not shown) is operating (step S1). (Step S2),
The alarm lamp 43 (corresponding to a warning means) arranged in the driving unit 27 is extinguished (step S3), and the front first and second front restraining regions B1 and B2 and the lateral check regions B1 and B2 Hydraulic cylinders 7, 11, 12, 13 in the restraint area B3
The deceleration operation of the (bucket 6) (step S4) and the stop operation of the hydraulic cylinders 7, 11, 12, 13 (bucket 6) on the front first and second check surfaces A1 and A2 and the lateral check surface A3 are performed. (Step S5) (corresponding to the operating state of the restraint means).

On the contrary, when the changeover switch 42 is turned off during the operation of the engine (not shown) (step S1) (step S2), the alarm lamp 43 is turned on (step S6), and the preceding paragraph (4). ) Front first and second front restraint regions B1 and B2 and lateral restraint region B3 as described in (6)
Hydraulic cylinders 7, 11, 12, 13 (bucket 6)
Deceleration operation and front first and second check surfaces A1, A
2, hydraulic cylinders 7, 11, 12, 1 on the lateral restraint surface A3
3 (bucket 6) is not stopped (corresponding to the stop state of the restraint).

As shown in FIGS. 4 and 5, a seating sensor 45 (presence or absence) for detecting whether or not the operator is seated on the driver's seat 28 due to the weight of the operator being applied to the driver's seat 28 of the driver unit 27. Equivalent to a sensor). Thus, while the engine (not shown) is operating (step S
1), the operator seated in the driver's seat 28 has a changeover switch 42
When the switch is turned off (step S2), this worker descends from the driver's seat 28 and leaves the operating part 27 (step S7), and this operator or another operator operates the operating part 27.
When you get in and sit in the driver's seat 28 (step S
8), the alarm buzzer 44 of the driving unit 27 (corresponding to warning means)
Is activated (step S9), and the alarm lamp 43 blinks (step S10) (the above corresponds to the control means).

Next, the changeover switch 42 is turned ON or O
After the engine is stopped while the FF is operated (step S11), the key switch (not shown) is turned on again.
ON to start the engine (step S1
2) The changeover switch 42 is automatically turned on regardless of the operation state of the changeover switch 42 before the engine is stopped (step S13), and the first and second front switches as described in the above (4) and (6) are performed. Deceleration operation (step S4) of the hydraulic cylinders 7, 11, 12, 13 (bucket 6) in the front second restraint regions B1 and B2 and the lateral restraint region B3, and the front first and second restraint faces A1 and A2; The hydraulic cylinders 7, 11, 12, 13 (bucket 6) are stopped on the lateral restraint surface A3 (step S5).

[First Embodiment] The structure shown in FIG. 7 may be used instead of the structure shown in FIG. As shown in FIG. 7, while the engine (not shown) is operating (step S1),
An operator sitting in the driver's seat 28 turns the changeover switch 42 off.
When the F operation is performed (step S2), this worker descends from the driver's seat 28 and leaves the driver's part 27 (step S2).
7) When this worker or another worker gets into the driver's seat 27 and sits on the driver's seat 28 (step S8), the process proceeds to step S13 and the changeover switch 42 is automatically turned ON.
The hydraulic cylinders 7, 11, 12, 13 (bucket 6) are decelerated (step S4) in the front first and second front restraint regions B1 and B2 and the horizontal restraint region B3, and the front first
Also, the hydraulic cylinders 7, 11, 12, 13 (bucket 6) are stopped at the front second check surfaces A1 and A2 and the horizontal check surface A3 (step S5) (above, control means and check) Equivalent to the operating state of the means).

As a result, in the configuration shown in FIG. 6, when the worker or another worker gets into the driver's seat 27 and sits down in the driver's seat 28 as described above, the alarm buzzer 44 remains turned off. Is activated and the alarm lamp 43
Blinks, whereas in the configuration of FIG. 7, when an operator or another operator gets into the driver 27 and sits in the driver's seat 28, the changeover switch 42 is automatically turned on.

[Second Alternative Embodiment] In the above-described embodiment and the first alternative embodiment, the front first and second front restraint surfaces A1 and A2 and the horizontal restraint surface A3 are set with reference to the tip and the left lateral surface of the bucket 6.
However, the potentiometer 39 shown in FIG. 1 is omitted, and the potentiometers 36, 37, and 38 are used as a reference, with the tip of the arm 5 (the connection point of the bucket 6) as a reference, to the front first and second check surfaces A1, A2 and a lateral restraint surface A3 may be set. Instead of the partition wall 29 and the roof portion 30, a cabin (not shown) that covers the operation unit 27 in a substantially closed room may be provided in the swivel base 2 and this cabin may be used as an external frame.

In the above-mentioned embodiment and the first alternative embodiment, the pilot operated type control valves 21 to 25 are operated via the electromagnetic proportional pressure reducing valve type pilot valves 31 to 35. The pilot valves 31 to 35 are abolished and the control valves 21 to 25 are configured as electromagnetic proportional pressure reducing valve types, and the operation positions of the right and left operation levers 9 and 10 and the operation pedal 26 are electrically detected by the potentiometers 15 to 18. Then, based on this detected value, the control valves 21 to 2 of the electromagnetic proportional pressure reducing valve type
5 may be directly operated. Instead of the seating sensor 45 in the above-described embodiment and the first alternative embodiment, a non-contact type sensor for detecting whether or not an operator is present in the driver's seat 28 or the operating section 27 by light or ultrasonic waves is used. You may use it as a presence sensor.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

1] Overall side view of backhoe

FIG. 2 is a schematic side view of a backhoe showing front first and second check surfaces and front first and second check regions.

FIG. 3 is a schematic front view of a backhoe showing front first and second check surfaces, front first and second check areas, lateral check surfaces, and horizontal check areas.

FIG. 4 is a schematic plan view of a backhoe showing a front first check surface, a front first check area, a lateral check surface, and a side check area.

FIG. 5: Hydraulic cylinders for the backhoe device, control valves,
Diagram showing the relationship between the pilot valve, right and left operating levers, etc.

FIG. 6 is a diagram showing a flow of control based on operation of a changeover switch.

FIG. 7 is a diagram showing a flow of control based on operation of a changeover switch in another embodiment.

[Explanation of symbols]

 2 swivel base 3 backhoe device 6 bucket 7, 11, 12, 13 hydraulic cylinder 27 operating part 29, 30 external frame 36, 37, 38, 39 position sensor 42 switching means 43, 44 warning means 45 presence / absence sensor A1, A2, A3 Restraint

Claims (2)

[Claims] 1. An operating unit (2) provided on a swivel base (2).
Checking surfaces (A1), (A2), (A) which are separated from the outer frames (29), (30) covering the outer surface 7) by a predetermined distance.
And a position sensor (36), (37), (38), (39) for detecting the position of the bucket (6) of the backhoe device (3). (36), (37), (38), (3
Based on the detection of 9), the bucket (6) crosses over the check surfaces (A1), (A2), (A3) and the operating unit (27).
When trying to get in, the hydraulic cylinders (7), (11), (1) for driving the backhoe device (3) are operated.
2) and (13) are provided with a restraining means for stopping and restraining the restraining means, a switching means (42) capable of artificially selectively switching the restraining means into an operating state and a stopped state, and the operating section. A sensor (45) for detecting whether or not an operator is present at (27), and warning means (43) and (44) are provided so that the engine is operating and the switching means (42) is stopped. When the presence / absence sensor (45) switches from a state in which the worker is detected to a state in which the worker is not detected in the state in which the operator is switched to, and the state in which the worker is detected again, the warning means (43), (44). ) Is equipped with a control means for operating the backhoe. 2. An operating unit (2) provided on a swivel base (2).
Checking surfaces (A1), (A2), (A) which are separated from the outer frames (29), (30) covering the outer surface 7) by a predetermined distance.
And a position sensor (36), (37), (38), (39) for detecting the position of the bucket (6) of the backhoe device (3). (36), (37), (38), (3
Based on the detection of 9), the bucket (6) crosses over the check surfaces (A1), (A2), (A3) and the operating unit (27).
When trying to get in, the hydraulic cylinders (7), (11), (1) for driving the backhoe device (3) are operated.
2) and (13) are provided with a restraining means for stopping and restraining the restraining means, a switching means (42) capable of artificially selectively switching the restraining means into an operating state and a stopped state, and the operating section. (27) is equipped with a presence sensor (45) for detecting whether or not there is an operator, and the presence sensor (45) is operated when the engine is operating and the switching means (42) is switched to a stopped state. When 45) switches from a state in which the worker is detected to a state in which it is not detected, and when it is switched to a state in which the worker is detected again, control means for automatically switching the switching means (42) from the stopped state to the operating state. A backhoe equipped with.