JPS63312432A - Controller for braking of slewing body - Google Patents

Abstract

PURPOSE:To shorten time lag by a method in which a parking brake is operated after the lapse of a given period from a time that a slewing operation lever is in neutral position and slewing speeds become less than a given value. CONSTITUTION:When a slewing lever L3 is restored to neutral position under a condition that a slewing motor 3 is turned, the speed N of the motor 3 is reduced to fall within fine speed ranges, and the presence of the lever L3 on neutral position is discriminated by a controller 16. The counting of set time which is set as a time to be taken for the motor 3 to become zero(0) speed from a given speed close to zero(0) is started to be determined whether it is counted up or not. The set time is counted up in a small period of time after the stoppage of the motor 3, and a switch valve 10 is switched to the left-side position by the controller 16 to operate a parking brake 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a braking control device for a rotating structure that controls the braking of a parking brake that provides mechanical braking force to a hydraulic motor that drives a rotating structure such as a working machine. .

[Conventional technology]

For example, a working machine has a revolving body to which a working arm is attached,
There are machines that carry out work by rotating the revolving body. Hydraulic excavators are a typical example. A hydraulic excavator has a plurality of hydraulic cylinders that drive working arms, and a hydraulic motor (hereinafter referred to as a swing motor) that drives an upper rotating body to which the working arms are attached. The hydraulic motor is equipped with a parking brake to ensure that it remains stopped. Hereinafter, the hydraulic circuit of such a hydraulic excavator will be explained using diagrams.

FIG. 6 is a system diagram of the hydraulic circuit of the hydraulic excavator. In the figure, 1 is a hydraulic pump, 2 is an engine that drives the hydraulic pump 1, 3 is a swing motor driven by the pressure oil of the hydraulic pump 1,
Reference numeral 4 denotes an upper rotating body connected to the swing motor 3 via a speed reducer. 5 and 6 are actuators each driven by pressure oil of the hydraulic pump 1, such as a boom cylinder and an arm cylinder. 7 is a directional control valve block, and a swing morph 3. The direction switching valves of the boom cylinder 5 and the arm cylinder 6 are integrally constructed.

L3. L5. L6 is a swing motor operating lever (swing lever), a boom cylinder operating lever (boom lever), and an arm cylinder operating lever (arm lever), respectively. Moreover, K 3 + K 5 + K b are lever position detectors, and are respectively used for swing lever L3 + boom lever L.
5 and the operating position of the arm lever L6 and outputs an electric signal in accordance with this.

8 inputs signals from each lever position detector K3+KS+Kb, and operates the directional control valve block 7 according to the signals.
Switch the corresponding directional control valve.

A parking brake 9 provides mechanical braking force to the swing motor 3, and is composed of a cylinder. A spring 9S is interposed on the bottom side of this cylinder. 10 is an electromagnetic switching valve that controls the driving of the parking brake;
1 is a pilot pump that drives the parking brake 9. 12 indicates a hydraulic oil tank.

Here, the parking brake 9 will be described.

When the upper rotating body 4 is stopped, if a force acts on the upper rotating body 4 for some reason, for example, when the hydraulic excavator is on a slope and a force due to the weight of the upper rotating body 4 acts, the swing motor 3 Oil leak may cause it to rotate, causing an unexpected accident. Therefore, a braking force is applied to the swing motor 3 by the parking brake 9 to prevent unintended rotation.

If such a parking brake 9 is used while the swing motor 3 is rotating, it may cause burn-out or damage, so it is used only when the swing motor 3 is stopped.

The driving of the parking brake 9 is controlled by the control section 8. That is, the control unit 8 manually inputs a signal 3 to the lever position detector, and when the swing lever L3 is operated from the neutral position in either direction, the switching valve 10 is switched to the illustrated position, and the pressure oil of the pilot pump 11 is switched off. It is supplied to the rod side of the cylinder that constitutes the parking brake 9 to release the brake. On the other hand, when the swing lever L3 is returned to the neutral position while the swing motor 3 is swinging, the control unit 8 starts counting a preset time, and after the elapse of that time, switches the switching valve 10 to the right position in the figure. , the oil on the rod side of the parking brake 9 is discharged into the tank 12, and the parking brake 9 performs braking by the spring force of the spring 9S.

[Problem that the invention seeks to solve]

By the way, in order to prevent seizure and damage to the parking brake 9 as described above, the above-mentioned time preset in the control unit 8 is set so that the swing motor 3 can completely stop under any conditions. selected in sufficient time. That is,
The time from when the swing lever L3 is set to the neutral position until the swing motor 3 stops varies depending on the magnitude of the load, the front posture of the hydraulic excavator, whether the hydraulic excavator is on a slope, etc. Therefore, the above-mentioned time set in the control section 8 must be the longest time taking into consideration all these conditions. However, it is extremely rare for a hydraulic excavator to be under the conditions where the above time is the longest, and in many cases, the time from when the swing lever L3 is set to the neutral position until the swing motor 3 stops is longer than the above set time. much shorter. Therefore, normally the swing motor 3
There is a considerable time lag between when the parking brake 9 stops and when the parking brake 9 is activated, and during this time the parking brake 9 cannot apply braking force, which may cause the swing motor 3 to rotate. A problem arose. Such problems occur not only in upper revolving structures of hydraulic excavators, but also in various other revolving structures.

SUMMARY OF THE INVENTION An object of the present invention is to provide a braking control device for a swinging structure that solves the problems of the prior art described above and can shorten the time from when the swing motor stops until the parking brake is activated.

[Means for solving problems]

In order to achieve the above object, the present invention provides a swing motor that is controlled by a swing operation lever, a swing body that is driven by the swing motor, and a parking brake that applies a braking force to the swing motor. , a swing speed detection means for detecting a swing speed of the swing structure; a lever position detection means for detecting a neutral position of the swing operation lever; The parking brake is characterized by further comprising a control section that outputs a braking command to the parking brake after a predetermined time has elapsed since the time when the parking brake has reached a predetermined value.

[Effect]

The control section always inputs signals from the lever position detection means and the swing speed detection means, and also sets a predetermined short time. When the swing operation lever is placed in the neutral position while the swing motor is swinging, the swing motor is decelerated until its speed reaches a certain predetermined value.

When this speed is detected by the swing speed detection means, the control unit starts counting the set time, and when the time has counted up, outputs a braking command to the parking brake, and applies the braking force of the parking brake to the swing motor. give.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a system diagram of a hydraulic circuit of a hydraulic excavator using a brake control device for a rotating body according to an embodiment of the present invention. In the figure,
Components that are the same as those shown in FIG. 6 are designated by the same reference numerals, and their explanation will be omitted. 15 is a speed detector for detecting the rotation speed of the swing motor 3, and 16 is a control section corresponding to the control section 8 shown in FIG.

The control unit 16 inputs the detection signal X3 of 3 and the detection signal N of the speed detector 15 to the lever position detector of the swing lever L3, controls switching of the switching valve 10 based on these, and drives the parking brake 9. Control.

Next, the operation of this embodiment will be explained with reference to the waveform diagrams shown in FIGS. 2(a) to 2(C) and the flowchart shown in FIG. 3. In order to minimize the time from when the swing motor 3 stops until the parking brake is activated, that is, the time lag, the parking brake may be activated when the stop of the swing motor 3 (speed 0) is detected. However, since it is extremely difficult to detect the speed O, in this embodiment, instead of the speed 0, a certain speed N0 close to the speed O is determined as shown in FIG. 2 (G). And the rotation motor 3
A time ΔT that is assumed to be required for the speed to change from speed N0 to speed 0 is determined, and this becomes the set time.

Further, since the processing in the control unit 16 is performed digitally, only the values before and after the speed N0 are read, and when the speed N0 is exactly
There is a possibility that the value may not be read. In order to prevent this, in this embodiment, as shown in FIG.
N>No. ) is determined, and the detected speed N is the speed N. Instead of comparing whether or not the detected speed N is within the minute speed range ΔN.

The control unit 16 constantly outputs a speed signal N and a swing lever position signal X3.
(Step S+ in the flowchart of FIG. 3). Now, time t. When the swing lever L3 is operated to swing the swing motor 3 as shown in FIG. 2 (al), the speed of the swing motor 3 increases as shown in FIG. 2 (bl). Immediately after the operation of L3, the speed of the swing motor 3 is almost 0, and the signal N is determined to be within the minute speed range ΔN (step Sz).
. As a result, the process moves to step S4, and the turning lever L3
It is determined whether or not the is being operated. In this case, since the turning lever L3 has already been operated, the process is performed in step S5.
The control section 16 then sets the time ΔT in its internal counter (step SS), and then releases the parking brake 9 in step S3. When the speed of the swing motor 3 increases, its speed N goes outside the minute speed range ΔN, and the process repeats steps S to S3.

In this state where the swing motor 3 is swinging,
When the swing lever L3 is returned to the neutral position from time t1 to time t2 as shown in FIG.
As shown in 1, the speed of the swing motor 3 gradually decreases and eventually enters a very small speed range ΔN.

The control unit 16 determines this in step S2, and then determines whether the swing lever L3 is in the neutral position (step S4).
. In this case, since the swing lever L3 is in the neutral position, the counter starts counting the set time ΔT previously set in the counter as shown in FIG. (step S6).

On the other hand, the time ΔT is set to be long to a certain extent in order to prevent seizure or damage to the parking brake 9, so the above steps S l + S z, S 4 + S6
During the +Sl repetition process, the swing motor 3 stops at time t, as shown in FIG. 2(b). Then, in a short period of time TL thereafter, the count of time ΔT increases, and as a result, the control unit 16 switches the switching valve 10 to the right position in FIG. 1, as shown in FIG. 2, and operates the parking brake 9. (Step Sq). The activation time of the parking brake 9 is shown in FIG. 2 (time C1). Also, the above-mentioned time TL becomes a time lag.

In this way, in this embodiment, the time ΔT until the parking brake is activated is set based on the time when the speed of the swing motor reaches the minute speed range ΔN centered on the speed N0 close to 0, so that the time lag is reduced. TL can be shortened, and movement of the rotating body after it has stopped can be more reliably prevented. That is, in the conventional device, as shown in Fig. 2 fa), since the reference is taken when the swing lever is in the neutral position, it is inevitably difficult to estimate the stop time of the swing motor, and the setting Therefore, the time lag TL must be selected to be a long time.
' is also often long. On the other hand, in this embodiment, by using the above-mentioned criteria, it is possible to estimate the stop time of the swing motor with a considerable degree of accuracy, and it is possible to shorten the set time ΔT and shorten the time lag TL. can.

Next, other embodiments of the present invention will be described.

This other embodiment differs from the previous embodiment only in the configuration of the control section, and the other configurations are the same, so the explanation will be given with reference to a flowchart.

FIG. 4 is a flowchart illustrating the operation of a braking control device for a rotating body according to another embodiment of the present invention. Generally, when carrying out work such as excavation with a hydraulic excavator, it is desirable to release the parking brake 9. The reason for this is that, for example, when excavating, when excavation reaction force acts on the upper revolving structure 4, in addition to the hydraulic braking force, the parking brake 9
This is because the braking force will also oppose the excavation reaction force, and if the excavation reaction force is large, there is a risk that the speed reducer will be damaged. Therefore, in this embodiment, even if the swing motor 3 is in a stopped state, if the other actuators 5 and 6 are being driven, the parking brake 9 is released. Everything is executed in the control section.

The control of this embodiment and the control of the previous embodiment are as follows: While the control of the previous embodiment takes in the speed signal N and the signal X3 of the swing lever L3 in step S, the control of this embodiment In addition, the difference is that the signal X of the boom lever L5 and the signal X6 of the arm lever L6 are also taken in (step S++), and the control in the previous embodiment is in step S4 and the signal x3 of the swing lever L3 is set to O. In contrast to only determining whether or not
The control in this embodiment is based on the turning lever F1. Boom lever LS
+Each signal of arm lever L6 X3. They also differ in that it is determined whether or not XS and X6 are all 0 (step S, 4). That is, the time T is changed only when the swing lever L 2 + boom lever arm 5 and arm lever L6 are all in the neutral position.
This is to start counting and activate the parking brake, otherwise the parking brake will not be activated to deal with the large excavation reaction force.

In this way, in this embodiment, the parking brake is released when even one operating lever is not in the neutral position (while work is being done), so in addition to the effects of the previous embodiment, Damage to the reducer due to reaction force from work can be prevented.

Next, still another embodiment of the present invention will be described. This embodiment also differs from the previous two embodiments only in the configuration of the control section, so it will be explained only with reference to flowcharts.

In the embodiment shown in FIG. 4, when the swing motor 3 is stopped and the operating lever of another actuator is being operated, when the operating lever is returned to the neutral position, the time Δ
The configuration was such that the parking brake 9 was activated after the T. However, if the swing motor 3 has already stopped, the parking brake 9 can be operated without fear of seizure or damage, so the above-mentioned time ΔT becomes a time lag (ie, TL - ΔT). Therefore, in this embodiment, the parking brake 9 is configured to operate immediately in such a case.

This will be explained below.

FIG. 5 is a flowchart illustrating the operation of a braking control device for a rotating structure according to still another embodiment of the present invention. First, when the boom lever is pressed and the arm lever L6 is not operated and only the swing lever L3 is operated, XS =
Since x6=o, the process is steps 5211 3221
5231 5Z41 After proceeding to S25 and setting the time ΔT, set the predetermined flag A to A=1 and proceed to step 526
), release the parking brake 9. When turning is stopped, it becomes X3-0, so the process is step S21+ S2□+
5231 S24+ 5ell, and when the time T has passed, activate the parking brake (
Step 529), set flag A to A=0.

Also, when the upper revolving body 4 is stopped, press the boom lever■
, 5 or arm lever L6 is operated, the process proceeds to steps S21+S2□ and S23, and since signal x5 or signal X6 is not O, next flag A is "1" or "
0" is determined. In this case, since the swing lever L3 has not been operated from the beginning, time T is not set, and in step 33+ it is determined that A=0, and the boom lever L5
Alternatively, while the arm lever L6 is being operated, the parking brake 9 is released in step S27. When the work is completed and both the poom lever Ls and the arm lever are in the neutral position, step 324 is X3-0,
In addition, since the signal from the counter is not a counting signal in step sin, the parking brake 9 is immediately activated in step 329.

Furthermore, if the operating lever L3 and the boom lever L5 or arm lever L6 are operated at the same time, step SZ
Even if T is set to the time in Step 5, ΔT is set to 0 in step S3°.

If the return of the swing lever 3 to the neutral position is faster than the return of the boom lever L5 or the arm lever L6 to the neutral position, the parking brake 9 is activated at the same time as the return of the boom lever or the arm lever L6 to the neutral position. Conversely, if the return of the swing lever L3 to the neutral position is slow, the time Δ
T is set, and the parking brake 9 is activated after that time has elapsed.

As described above, in this embodiment, if the boom lever or arm lever is operated and the swing motor is stopped when the boom lever or arm lever returns to the neutral position, the parking brake is activated immediately. In addition to the effects of the embodiment, the time lag during operation of other actuators can be eliminated.

In addition, in the description of the above embodiment, a hydraulic excavator was used as an example, but it is of course applicable to other working machines.

〔Effect of the invention〕

As described above, in the present invention, the parking brake is activated after a predetermined period of time has elapsed since the swing operation lever is in the neutral position and the swing speed has fallen below a predetermined value, thereby shortening the time lag. Therefore, it is possible to prevent danger due to unintended movement of the rotating body.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a hydraulic circuit of a hydraulic excavator using a braking control device for a rotating body according to an embodiment of the present invention, and Fig. 2
, (bl, (C) is a waveform diagram explaining the operation of the device shown in FIG. 1, FIG. 3 is a flowchart explaining the operation of the device shown in FIG. 1, and FIGS. 4 and 5 are each a diagram of the present invention. A flowchart explaining the operation of the braking control device for a revolving structure according to another embodiment of the present invention, and FIG. 6 is a system diagram of a hydraulic circuit of a hydraulic excavator. 1. Hydraulic pump, 3. single rotation motor,
4-----Upper revolving body, 9--Parking brake, 10--Switching valve, 11--Pilot pump, 1
5---Speed detector, L 3---One swing lever, K,---Lever position detector. Fig. 1 I: j [ll] Eng.・/Toho 0 nib 15:jL sequence diagram 3 Figure 4

Claims (3)

[Claims] (1) Detecting the turning speed of the rotating structure in a device equipped with a swing motor controlled by a swing operation lever, a swing structure driven by the swing motor, and a parking brake that applies braking force to the swing motor. a swing speed detection means for detecting a neutral position of the swing operation lever, a lever position detection means for detecting a neutral position of the swing operation lever, and a swing speed detection means for detecting a neutral position of the swing operation lever; 1. A braking control device for a revolving structure, comprising: a control section that outputs a braking command to the parking brake after a predetermined period of time has elapsed. (2) In claim (1), the control unit includes input means for inputting the position of the swing operation lever and the position of an operation lever of an actuator other than the swing motor, and the swing operation lever. and an output means for outputting a braking command to the parking brake after the predetermined time has elapsed since the operating lever of the other actuator is in the neutral position and the turning speed of the rotating body reaches the predetermined value. A braking control device for a rotating body characterized by: (3) In claim (1), the control unit includes input means for inputting the position of the swing operation lever and the position of an operation lever of an actuator other than the swing motor, and the swing operation lever. and a first actuator that outputs a braking command to the parking brake after the predetermined time has elapsed since the operating lever of the other actuator is in the neutral position and the turning speed reaches the predetermined value.
and a second output means that outputs a braking command to the parking brake immediately when the turning speed is 0 and the operating lever of the other actuator is returned from the operating position to the neutral position. A braking control device for a revolving structure, comprising: