JPH08158414A - Preventive device for erroneous operation for running of full revolving type construction machine - Google Patents

Abstract

PURPOSE: To prevent erroneous operation in running by sensing the revolving position of an upper revolving element of a full revolution type construction machine relative to its lower running body, and putting the turning direction of a running lever identical to the advancing direction of the lower running body. CONSTITUTION: A revolving position sensing device using limit switches 27, 28 is installed on a rotary joint 20. Solenoid valves 44 are installed on the way of pilot oil paths 40a, 40b and ones 41a, 41b which move spools of direction control valves 32, 33. If the revolving position sensing device judges that the revolving position of an upper revolving element is turned oppositely fore and aft, a solenoids 45 are energized or deenergized for changing-over of the solenoid valves 44, and the spools of the direction control valves 32, 33 are moved to the opposite positions so that the oil influx directions to running motors 15, 16 are switched fore and aft and on the left and right. Thus a lower running body advances in the opposite direction, and the turning directions of running levers 18, 19 are put identical to the advancing direction of the lower running body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a full swing type construction machine in which an upper revolving structure is rotatable in all horizontal directions with respect to a lower traveling structure. The present invention relates to a running error prevention device for a full-slewing construction machine that switches the traveling direction.

[0002]

2. Description of the Related Art A conventional running error preventing device for a full swing type construction machine of this type is known from Japanese Utility Model Publication No. 6-3888. In the device described in the publication, when the upper revolving structure is turned backward with respect to the lower traveling structure, the oil passages to the left and right traveling motors are switched to the front, rear, left and right by the solenoid valve to operate the traveling lever and lower traveling. It is designed so that the directions of movement of the body coincide.

[0003]

In the conventional travel erroneous operation preventing device, the oil passage to the left and right traveling motors is switched by the solenoid valve depending on the turning position of the upper swing body, but the lower swing body moves the upper swing body while traveling. In the case of turning, the solenoid valve automatically operates and the oil passages to the left and right traveling motors are switched. In that case, the left and right traveling motors suddenly rotate in the reverse direction and the lower traveling body advances in the opposite direction, which may cause an accident due to an operation contrary to the intention of the operator.

Therefore, when the turning position of the upper revolving superstructure of the fully revolving construction machine is reversed in the front-rear direction, when the lower traveling body is stopped, the oil inflow direction to the left and right traveling motors is changed to front, rear, left and right. While preventing the wrong operation of
A technical problem to be solved occurs in order to prevent the left and right traveling motors from suddenly rotating in reverse during turning of the lower traveling body, and an object of the present invention is to solve this problem.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to achieve the above object, and an upper revolving structure is mounted on a lower traveling structure provided with left and right crawlers so as to be rotatable in all horizontal directions. , Left and right traveling motors that drive the respective crawlers independently in the front-rear direction, left and right directional control valves that switch the oil passages to the respective traveling motors in the forward rotation direction or the reverse rotation direction, and spools of the respective directional control valves In a full swing type construction machine having a hydraulic circuit consisting of left and right traveling levers for switching between the hydraulic circuit and a rotary joint, a rotary position detecting device is provided in the rotary joint, and The turning position of the upper revolving structure can be determined, and the knobs of the left and right traveling levers are provided with display devices for the traveling directions, respectively, and a pressure sensor for detecting the operation of each traveling lever is provided. And a travel error preventing device for a full swing construction machine equipped with a solenoid valve for switching the inflow direction of oil to the left and right traveling motors to the front, rear, left and right in the hydraulic circuit, and the turning position detecting device. When it is determined that the revolving position of the upper revolving structure has been reversed, the solenoid of the solenoid valve is turned on or off to switch the solenoid valve. When it is determined by the position detection device that the turning position of the upper revolving structure is leftward or rightward, the traveling-direction construction machine configured to turn on or blink the traveling direction display device provided on the knobs of the left and right traveling levers. Travel misoperation prevention device, and
A holding circuit is provided in the solenoid of the solenoid valve, and when it is detected by the pressure sensor that the traveling lever is being operated, the holding circuit is actuated to operate the solenoid of the solenoid valve regardless of the determination result of the turning position detection device. The present invention provides a running error prevention device for a full swing type construction machine, which is maintained in an on or off state.

[0006]

When the upper revolving structure revolves, the revolving position detecting device provided in the rotary joint determines the revolving position of the upper revolving structure with respect to the lower traveling structure, and the revolving position of the upper revolving structure is reversed. At times, the solenoid of the solenoid valve is turned on, and the inflow direction of oil to the left and right traveling motors is switched between front, rear, left and right. Therefore, for example, if the traveling lever is operated to the forward side when the upper swing body is in the backward region, the lower traveling body will move in the backward direction, and the operation direction of the traveling lever and the traveling direction of the lower traveling body will coincide. To do.

Further, when the undercarriage is traveling, the pressure sensor detects that the traveling lever is being operated. In that case, the holding circuit is activated regardless of the determination of the turning position detecting device. The solenoid of the solenoid valve holds the ON or OFF state. Therefore, the left and right traveling motors do not reverse when the undercarriage continues to travel.

[0008]

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a hydraulic excavator 11 as an example of a fully revolving construction machine. An upper revolving structure 1 is mounted on a lower traveling structure 12 having left and right crawlers via a ball race 13.
4 is mounted so as to be rotatable in all horizontal directions. Left and right traveling motors 15 and 16 are mounted on the left and right rear portions of the lower traveling body 12, and the hydraulic circuits are controlled by the two traveling levers 18 and 19 provided in the cabin 17, so that the left and right traveling motors 15 and 16 are controlled. Drive each independently. Further, a rotary joint 20 is provided at the center of the ball race 13, and the lower traveling body 12 is provided through the rotary joint 20.
And the hydraulic circuit of the upper swing body 14 are connected.

Here, the range of the lower traveling body 12 with respect to the forward direction F is a forward region, the range is a backward region,
The range of is set to the leftward area, and the range of is set to the rightward area. The rotary joint 20 is provided with a turning position detecting device to be described later, and the control circuit 21 determines in which region the center line C of the boom of the upper-part turning body 14 is located based on the detection value of the turning position detecting device. Determine with.

A turning position detecting device 2 according to FIGS. 2 to 5.
2 will be described. As shown in FIGS. 2 and 3, the rotary joint 20 includes a housing 23 fixed to the lower traveling body 12 and a rotor 24 that rotates simultaneously with the upper revolving body 14 by a rotation stopper (not shown). A hollow cylindrical cam 25 is fixed to the upper portion of the housing 23 so as to surround the rotor 24. The cam 25 is 2 up and down
As shown in FIGS. 4 and 5, the outer diameter of the cam 25 has a small diameter in both the upper stage and the lower stage in the frontward region, and the upper and lower stages in the rearward region. Both have a large diameter. In the leftward region, the upper stage of the cam 25 has a large diameter and the lower stage has a small diameter, and in the rightward region, the upper stage has a small diameter and the lower stage has a large diameter.

On the other hand, as shown in FIGS. 2 and 3, two limit switches 27 and 28 are fixedly mounted on the upper swing body 14 via a bracket 26, and one arm of the limit switch 27 has the cam 25. Of the limit switch 28 is in contact with the lower side surface of the cam 25. When the limit switches 27 and 28 are in contact with the large diameter position of the cam 25, the arm is pressed to turn on, and when the limit switches 27 and 28 are in contact with the small diameter position of the cam 25, the pressing of the arm is released. It is set to turn off.

When the upper revolving structure 14 is in the frontward region with respect to the lower traveling structure 12, the upper and lower limit switches 27 and 28 are both in contact with the small diameter position of the cam 25. Limit switches 27 and 2
Both 8 are off. Here, when the upper revolving structure 14 enters the leftward region with respect to the lower traveling structure 12, the lower limit switch 28 remains off but the upper limit switch 27 switches on.

Further, when the upper revolving structure 14 enters the rearward area with respect to the lower traveling structure 12, the lower limit switch 2
8 is also switched on and limit switches 27 and 28
Are both turned on. When the upper swing body 14 enters the rightward region with respect to the lower traveling body 12, the lower limit switch 28 remains on but the upper limit switch 27 switches off.

[0014]

[Table 1]

Thus, as shown in Table 1, the control circuit 21 determines in which region the swing position of the upper swing body 14 is located based on the mutual switching states of the upper and lower limit switches 27 and 28. To do. Although the limit switches 27 and 28 are used for the turning position detecting device 22 in the present embodiment, the present invention is not limited to this, and other detecting means such as a proximity switch or an optical sensor may be used. .

Further, as shown in FIG. 6, the cabin 1
Knobs 18a of the left and right traveling levers 18 and 19 provided on the
A left display device 29 and a right display device 30 are provided on the surfaces of the display devices 19 and 19a, respectively. In the left display device 29, a left-side light emitting portion 29a is attached to the front side of the knob 18a, and a right-side light emitting portion 29b is attached to the rear side of the knob 18a. On the other hand, in the display device 30 on the right, the light emitting portion 30a facing right is attached to the front side of the knob 19a, and the light emitting portion 30b facing left is attached to the rear side of the knob 19a. Each display unit 29a,
29b and 30a, 30b respectively use LEDs, lamps, neon tubes, etc.
By lighting or blinking b or 30a, 30b, the operator is made to recognize the traveling direction of the lower traveling body.

FIG. 7 shows a hydraulic circuit, and the main pump 31
The hydraulic oil discharged from the left and right direction control valves 32 and 33
The direction is controlled by the rotary joint 20, and the oil is led to the oil passage 34a or 34b to the left traveling motor 15 and the oil passage 35a or 35b to the right traveling motor 16 via the rotary joint 20. Left and right oil passages 34a, 34b and 35a, 35b
Counter balance valves 36 and 37 are interposed in the middle of the process.

The left and right traveling levers 18 and 19 are connected to pilot valves 38 and 39, respectively, and the left and right pilot oil passages 40a, 40b and 41a, 41b are the pilot ports 42a, 42b of the direction control valves 32 and 33, respectively.
And 43a, 43b. A solenoid valve 44 is provided in the middle of the left and right pilot oil passages 42a, 42b and 43a, 43b.
When 5 is off, the spool is at the position of 44a as shown in the drawing, the left pilot oil passages 40a and 40b are connected to the pilot ports 42a and 42b of the left directional control valve 32, respectively, and the right pilot oil passages are connected. 41a, 41
b is the pilot port 43 of the right directional control valve 33.
a, 43b.

On the other hand, when the solenoid 45 is on, the spool moves to the position of 44b as shown in FIG. 8, and the left pilot oil passages 40a and 40b are respectively in the pilot port 43b of the right directional control valve 33. , 43a and the right pilot oil passages 41a, 41b are respectively connected to the pilot ports 42b, 42 of the left directional control valve 32.
connected to a. Therefore, the spools of the left and right directional control valves 32 and 33 move in the direction opposite to that of FIG. 7 in response to the operation of the travel levers 18 and 19, and the left and right travel motors 15 and 1 move.
The flow of oil to 6 will be swapped between front, back, left and right. Further, regardless of the position of the solenoid valve 44, when the left and right traveling levers 18 or 19 are operated, the shuttle valve 4
Pilot oil is led to the pressure sensor 49 via 6, 47 and 48, and the pressure sensor 49 is turned on to detect that the traveling lever 18 or 19 is operated.

FIG. 9 shows an electric circuit including the control circuit 21. When the turning position of the upper revolving structure 14 with respect to the lower traveling structure 12 is in the forward-facing region, the limit switches 27 and 28 as shown in Table 1 are shown. Since both are off, the relays 50 and 51 are not excited, the solenoid 45 is turned off, and the solenoid valve 44 enters the state shown in FIG. When the left and right traveling levers 18 and 19 are operated to the forward side in this state, pilot oil is discharged to the pilot oil passages 40a and 41a, and the spools of the left and right direction control valves 32 and 33 are switched to the forward positions 32a and 33a. The traveling motors 15 and 16 of (1) rotate normally, and the lower traveling body 12 travels in the forward direction.

Next, the upper revolving structure 14 is turned right while the lower traveling structure 12 is moved forward, and the upper revolving structure 14 is stopped in the rearward-facing region while continuing the traveling of the lower traveling structure 12. In that case, since both the limit switches 27 and 28 are on as shown in Table 1, as shown in FIG. 10, the B contacts 27b and 2 of both limit switches are turned on.
8b opens and both A contacts 27a and 28a close.
However, the operation of the traveling levers 18 and 19 is detected, the pressure switch 49 is in the ON state, and the B contact 49b of the pressure switch is in the open state, so the relay 50 is not excited. Therefore, the A contact 50a of the relay 50 is held in the open state and the relay 51 is not excited, and the A contact 51a of the relay 51 is also held in the open state, so that the solenoid 45 remains off.

Thus, the solenoid valve 44 holds the position shown in FIG. 7, and the left and right direction control valves 32 and 33 are not switched. Therefore, even after the upper swing body 14 has swung from the frontward region to the rearward region, the left and right traveling motors 15 and 16 continue to rotate forward, and the lower traveling body 12 continues to travel in the forward direction.

If the traveling levers 18 and 19 are returned to the neutral position and the traveling of the lower traveling body 12 is stopped, as shown in FIG.
The pressure switch 49 is turned off as shown in FIG. 3, the B contact 49b of the pressure switch is closed, and the relay 50 is excited as shown by the solid line in FIG. Therefore, A of relay 50
The contact 50a is closed. When the traveling levers 18 and 19 are operated to the forward side again from this state, the pressure switch 49 is turned on and the A contact 49a of the pressure switch is closed as shown by the two-dot chain line in the figure. As previously mentioned,
Since the A contact 50a of the relay 50 is closed, the relay 51 is excited so that the A contact 51a of the relay 51 is closed, the closed state is maintained by the self-holding circuit, and the solenoid 45 is turned on.

Thus, as shown in FIG. 8, the solenoid valve 4
The spool No. 4 switches to the position 44b. Therefore, the left and right traveling levers 18 and 19 are still operated, but the spools of the left and right directional control valves 32 and 33 move from the forward positions 32a and 33a to the reverse positions 32b and 33b.
, And the inflow direction of oil to the traveling motors 15 and 16 is switched between front, rear, left and right, and the left and right traveling motors 15 and 16 are rotated in the reverse direction. That is, the lower traveling body 12 starts traveling in the backward direction with the upper revolving structure 14 in the rearward-facing region with respect to the lower traveling structure 12, and the operating directions of the traveling levers 18 and 19 and the lower traveling structure 12 of the lower traveling structure 12. The directions of travel are the same.

When the lower traveling body 12 continues to travel in such a state, the upper revolving superstructure 14 is revolved to another area to contact the A contacts 27a and 2 of the limit switches 27 and 28.
Even if either or both of the 8a are opened, the A contact 51a of the relay 51 maintains the closed state by the self-holding circuit described above, and the solenoid 45 remains in the on state. Therefore, the solenoid valve 44 holds the position shown in FIG. 8, the left and right direction control valves 32 and 33 are not switched, and the lower traveling body 12 continues traveling in the reverse direction.

When the traveling levers 18 and 19 are returned to the neutral position, the pressure switch 49 is turned off, the A contact 49a of the pressure switch is opened, and the A contact 51 of the relay 51 is opened.
When a is released, the solenoid 45 is turned off again.

As described above, even when the upper revolving structure 14 is turned while the lower traveling structure 12 is traveling, and the upper revolving structure 14 is turned in the opposite direction to the lower traveling structure 12, the The traveling motors 15 and 16 do not suddenly reverse and the lower traveling body 12 does not move in the opposite direction, so that the combined operation of traveling and turning can be performed with peace of mind. Then, after the traveling of the lower traveling body 12 is stopped, the oil passage is switched by the solenoid valve 44, and the operating directions of the traveling levers 18 and 19 and the traveling direction of the lower traveling body 12 coincide with each other, which may cause an incorrect operation by the operator. Can be prevented.

Here, when the upper revolving structure 14 is located in the leftward area with respect to the lower traveling structure 12, as shown in Table 1, the limit switch 27 is on and the limit switch 28 is off, as shown in FIG. As shown in, the A contact 27a of the limit switch 27 and the limit switch 28
The B contact 28b is closed and the light emitting portions 30a and 30b are energized. Therefore, the knob 19 of the right traveling lever shown in FIG.
When the display device 30 provided in a is turned on or blinks and the left and right traveling levers 18 and 19 are operated forward, the lower traveling body 12 advances to the right of the operator and the traveling levers 18 and 19 are operated backward. When running, the undercarriage 12
Can be seen to move to the left of the operator.

On the other hand, when the upper revolving structure 14 is located in the rightward region with respect to the lower traveling structure 12, the limit switch 27 is turned off and the limit switch 28 is turned on, as shown in Table 1. As shown, the B contact 27b of the limit switch 27 and the A contact 28a of the limit switch 27 are closed to energize the light emitting units 29a and 29b. Therefore, the knob 18a of the left traveling lever shown in FIG.
When the display device 29 provided on the vehicle lights up or blinks and the left and right traveling levers 18 and 19 are operated forward, the lower traveling body 12 advances to the left of the operator and operates the traveling levers 18 and 19 backward. At this time, it can be visually recognized that the lower traveling body 12 advances to the right of the operator.

Thus, in the leftward and rightward regions where it is difficult to confirm the orientation of the lower traveling body 12, the traveling directions of the lower traveling body 12 with respect to the operating directions of the traveling levers 18 and 19 are displayed on the display devices 29 and 30. It becomes clear that the operator can perform traveling operation without checking the positions of the traveling motors 15 and 16 each time.

Although the relays 50 and 51 are used in the control circuit 21 to control the solenoid 45 of the solenoid valve 44 in the present embodiment, a microcomputer is used as a control unit to provide the same function. Solenoid valve 44 by executing the program
The solenoid 45 may be controlled.

Therefore, the present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention covers the modifications.

[0033]

As described in detail in the above-mentioned one embodiment of the present invention, when the turning position detecting device determines that the turning position of the upper revolving superstructure is reversed in the front-rear direction, the inflow direction of oil to the traveling motor is changed. Since the front and rear and the left and right are interchanged, the operation direction of the traveling lever and the traveling direction of the lower traveling body coincide with each other, and the operator does not feel uncomfortable. Since the switching of the oil passage is performed when the traveling of the lower traveling body is stopped, the lower traveling body does not suddenly move in the opposite direction during the combined operation of turning and traveling, and safety can be secured.

When the upper revolving structure is positioned leftward or rightward with respect to the lower traveling structure, the display device provided on the knob of the traveling lever lights up or blinks to notify the traveling direction. The traveling direction of the undercarriage can be confirmed without checking the positions of the left and right traveling motors, and the traveling lever can be operated with confidence.

As described above, the present invention has various kinds of effects, such as preventing erroneous operation of traveling of the full swing type construction machine and contributing to improvement of operability and safety.

[Brief description of drawings]

FIG. 1 is a plan view of a hydraulic excavator showing an embodiment of the present invention.

FIG. 2 is a plan view of a turning position detecting device.

FIG. 3 is a partial sectional front view of a turning position detecting device.

FIG. 4 is an end view of the cam of FIG. 3 taken along the line AA.

5 is an end view of the cam in FIG. 3 taken along the line BB.

FIG. 6 is a perspective view of a main part of the traveling lever viewed from the rear side.

FIG. 7 is a hydraulic circuit diagram in which a solenoid of a solenoid valve is in an off state.

FIG. 8 is a hydraulic circuit diagram in which a solenoid of a solenoid valve is in an ON state.

FIG. 9 is a diagram showing an operating state of a control circuit.

FIG. 10 is a diagram showing an operating state of a control circuit.

FIG. 11 is a diagram showing an operating state of a control circuit.

FIG. 12 is a diagram showing an operating state of a control circuit.

FIG. 13 is a diagram showing an operating state of a control circuit.

[Explanation of symbols]

 11 hydraulic excavator 12 lower traveling body 14 upper revolving structure 15, 16 traveling motor 18, 19 traveling lever 18a, 19a knob 20 rotary joint 21 control circuit 22 rotational position detection device 29, 30 display device 32, 33 directional control valve 34a, 34b , 35a, 35b Oil passage 38, 39 Pilot valve 40a, 40b, 41a, 41b Pilot oil passage 44 Solenoid valve 45 Solenoid 49 Pressure sensor 50, 51 Relay Forward area Leftward area Leftward area Rightward area

Claims (4)

[Claims] 1. An upper revolving structure is mounted on a lower traveling structure having left and right crawlers so as to be rotatable in all horizontal directions, and left and right traveling motors for independently driving the respective crawlers in the front-rear direction, and respective traveling motors. A hydraulic circuit consisting of a left and right directional control valve that switches the oil passage to the traveling motor in the forward rotation direction or the reverse rotation direction and a left and right traveling lever that switches the spool of each directional control valve is provided, and the hydraulic pressure is supplied via a rotary joint. In an all-slewing construction machine with a circuit connected, the rotary joint is equipped with a swivel position detection device to enable the swivel position of the upper revolving structure to be determined with respect to the lower traveling structure, and to advance to the knobs of the left and right traveling levers respectively. A direction display device is provided, and a pressure sensor that detects the operation of each travel lever is provided. A running error prevention device for a full-swing construction machine, which is equipped with a solenoid valve that can be switched to the left and right. 2. The solenoid valve of the solenoid valve is turned on or off to switch the solenoid valve when it is determined by the swing position detection device that the swing position of the upper swing body is reversed in the front-rear direction. Erroneous operation prevention device for full swing type construction machinery. 3. When the turning position detection device determines that the turning position of the upper turning body is leftward or rightward, the traveling direction display device provided on the knobs of the left and right traveling levers is turned on or blinked. The running error prevention device for a full swing type construction machine according to claim 1. 4. A holding circuit is provided in the solenoid of the solenoid valve, and when the pressure sensor detects that the traveling lever is being operated, the holding circuit operates regardless of the determination result of the turning position detecting device. The erroneous traveling operation preventing device for a full swing construction machine according to claim 2, wherein the solenoid of the solenoid valve is maintained in an on or off state.