JPH06313402A - Preventive device for swing return of inertia body - Google Patents

Abstract

PURPOSE:To provide a preventive device for the swing return of an inertia body whose effect is sure and whose performance does not change due to temperature and whose structure is simple and which possesses high reliability. CONSTITUTION:A hydraulic motor 5 whose output shaft 13 is connected to an inertia body 14, and relief passages 15, 16 which are arranged between a pair of main pipe passages connected to the hydraulic motor 5 and possess relief valves 15, 16 that open when the oil pressure of one side main pipe passage rises over a predetermined value, are provided. After the feed of oil pressure from one side main pipe passage to the hydraulic motor 5 is stopped, the oil pressure of the other side main pipe passage that has risen due to the inertia force of the inertia body 14 is kept at fixed pressure by the brake operation of the relief valves 15, 16, and then, inertia energy is gone, and the pressure of the main pipe passages has lowered, and then, a brake mechanism B is engaged with the output shaft 13 of the hydraulic motor 5. The device possesses this mechanism B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing swingback of an inertial body such as a swinging body of a construction machine.

[0002]

2. Description of the Related Art In a conventional general device, when an attempt is made to stop a revolving structure, the torsional energy (inertial force) of the revolving structure causes swaying back, which makes it difficult to accurately stop the revolving structure at an expected position. Met. As a countermeasure against this, the applicant of the present invention has proposed Japanese Patent Publication No. 2-58481, but its effect was insufficient because it tried to prevent the swing-back by hydraulic pressure. That is, even if an attempt is made to absorb the torsional energy by hydraulic pressure, if the absorption is insufficient, the energy remains and the effect of preventing swingback tends to be insufficient. In addition, since the throttle is used in the hydraulic control, the characteristics deteriorate, especially at low temperatures, and the swing-back prevention effect tends to be insufficient.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an inertial body sway-back preventing device which is reliable in effect, has no change in performance due to temperature, has a simple structure, and is highly reliable.

[0004]

The present invention is arranged between a hydraulic motor having an output shaft connected to an inertial body and a pair of main pipelines communicating with the hydraulic motor so that the hydraulic pressure of one of the main pipelines is a predetermined value or more. The relief passage having a relief valve that opens when it rises, and the hydraulic pressure in the other main pipe line that rises due to the inertial force of the inertial body after the supply of the hydraulic pressure from one main pipe line to the hydraulic motor has stopped is the braking action of the relief valve. The inertial body swing-back prevention device having a brake mechanism that engages with the output shaft of the hydraulic motor after the inertial energy disappears after the pressure is maintained at a constant pressure and the pressure in the main conduit decreases.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a construction machine or the like in operation. The discharge port of a pump 1 is a passage 2, a control valve 3,
The other main pipe line 6 communicating with the suction port of the hydraulic motor 5 (which becomes the discharge port at the time of reverse rotation) and the discharge port of the hydraulic motor 5 (which becomes the suction port at the time of reverse rotation) via one main pipe line 4
Communicates with the tank 8 via the control valve 3 and the passage 7. The control valve 3 is connected to the remote control valve 11 via the signal path 10, and the operation lever 12 of the remote control valve 11 is connected.
The (joystick) is located at the left of the three positions of neutral and left and right, and the output shaft 13 of the hydraulic motor 5 gives the inertial body 14 such as the upper swing body of the shovel a left rotation.

From the main pipes 4, 6, the relief valves 15, 16
The relief passages 17 and 18 having the branch are branched, and the junction of the relief passages 17 and 18 communicates with the passage 7 via the passage 19. Passages 22 and 23 having check valves 20 and 21 branch off from the main pipes 4 and 6, and a junction point of the passages 22 and 23 communicates with the passage 19.

A shuttle valve 26 in the middle of a passage 25 connecting the main pipe lines 4 and 6 close to the hydraulic motor 5 communicates with a first switching valve 28 via a passage 27. The first switching valve 28 and the second switching valve 29 are both connected via the passage 30 to the remote control valve 1
1 and the handle 12 is in a position other than neutral, the remote control valve 11 via the passage 30 the switching valve 28,
The turning command pressure is supplied to 29. Three
Reference numerals 1 and 32 are compression springs, 33 and 34 are passages communicating with the tank 8, and 35 is a throttle.

The pilot pressure source 37 communicates with a working chamber 42 of a brake cylinder 41 via a passage 38, a switching valve 29, a passage 39, a switching valve 28 and a passage 40. The brake cylinder 41 is fixed to a frame (not shown), and the piston 43 fitted inside is in the waiting position at the right end shown in the figure against the elastic force of the compression spring 36 due to the hydraulic pressure in the working chamber 42, and is integrated with the piston 43. The rod 44 penetrates through the hole in the left end wall of the brake cylinder 41 while maintaining liquid tightness, and the brake pad 45 fixed to the left end faces the output shaft 13 with a slight gap. The brake pad 45 and the brake cylinder 41 form a brake mechanism B.

As described above, FIG. 1 shows a state in which the handle 12 is operated to the left position and the output shaft 13 rotates counterclockwise to drive the inertial body 13. From this state, when the handle 12 is operated to the neutral position, the control valve 3 is returned to the neutral position by the signal from the remote control valve 11, and the main pipes 4 and 6 are blocked by the control valve 3 portion. The supply of oil to the hydraulic motor 5 is stopped, and the discharge of oil from the main pipe line 6 is also stopped. But,
Since the hydraulic motor 5 tries to continue left rotation due to the inertia of the inertial body 13, the hydraulic pressure of the main pipe line 6 rises, and the hydraulic motor 5
When a braking force acts on the hydraulic pressure and the hydraulic pressure rises above a predetermined value, the relief valve 16 opens, and the main pipe line 6 is provided with the passage 18 and the relief valve 1.
6, the passages 19 and 22, and the check valve 20 communicate with the main pipe line 4, and the oil circulates. The oil pressure generated in the main pipeline 6 acts on the switching valve 28 via the passage 25, the shuttle valve 26, and the passage 27. Switching valve 28
Is stopped at the position shown in the figure, while the switching valve 29 is switched to the X side by the elasticity of the spring 32 due to the disappearance of the turning command pressure in the passage 30, and the passage 39 communicates with the passage 34. Since it is throttled by the diaphragm 35, it does not drop sharply, and the brake mechanism B maintains the standby state. After the hydraulic pressure of the main pipe line 6 is applied to the relief valve 16, the inertia force disappears, so that the supply from the motor 5 disappears and a fixed amount (for example, 1/3)
When the pressure decreases, the switching valve 28 is switched to the X side by the elasticity of the spring 31 due to the decrease in the hydraulic pressure acting on the switching valve 28 from the passage 27, and the passage 40 communicates with the tank 8 via the passage 33 to operate. Due to the disappearance of the hydraulic pressure in the chamber 42, the piston 43 and the rod 44 project leftward by the elastic force of the spring 36, the brake pad 45 abuts against the output shaft 13, and the output shaft 13 is stopped.

While the output shaft 13 is stopped by the operation of the brake mechanism B, some external force acts on the inertial body 14 to forcibly drive the output shaft 13 to the left, and the main pipe line 6
Even if the switching valve 28 is switched to the Y side as shown in FIG. 1 due to the increase in the hydraulic pressure of the tank 8, the switching valve 29 is held on the X side. Since the brake pad 45 does not loosen and the braking action continues, the movement of the inertial body 14 due to the external force is prevented as much as possible.

Next, the handle 12 of the remote control valve 11 is shown in FIG.
When the control valve 3 and the switching valves 28 and 29 are switched to the left position shown in (4), the brake mechanism B releases the output shaft 13, and the output shaft 13 rotates to the left.

As described above, the revolving body (the inertial body 1
4) When the driving pressure of the hydraulic motor 5 for driving 4) is decreased, the stop of the hydraulic motor 5 is detected. When the turning command pressure of the passage 30 is decreased, the brake release pressure of the working chamber 42 is released, and the brake mechanism B is turned on. It is actuated and the inertial body 14 is securely held to prevent the swing-back. That is, when the turning command pressure is applied to the passage 30, the brake mechanism B is released. There is no turning command pressure in the passage 30,
In addition, when the swing drive pressure remains in the main pipe line 6, the switching valve 2
8 is in the illustrated Y state, the switching valve 29 is in the X state, and the throttle 35
Thus, the operation of the brake mechanism B is delayed until the inertial body 14 is stopped. When the rotation of the inertial body 14 is stopped while the operation of the brake mechanism B is delayed and the driving pressure of the main pipe line 6 is reduced, the switching valve 28 is switched to the X side, the brake mechanism B is immediately operated, and the hydraulic motor 5 is driven. Holds securely and prevents swinging back. When the output shaft 13 is externally rotated with an excessive torque from the state in which there is no turning command pressure in the passage 30 and no motor drive pressure, the brake mechanism B slips and the main pipeline 6
Although the holding pressure of the hydraulic motor 5 rises, the presence of the switching valve 29 switched to the X side prevents the brake mechanism B from being released. As the brake mechanism B, it is possible to employ a structure in which a brake drum (not shown) fixed to the output shaft 13, the inertial body 14, a coupling mechanism between the both, and the like is fastened with a brake band.

FIG. 2 shows another embodiment, and the same symbols as those in FIG. 1 are corresponding parts. Also in FIG. 2, the output shaft 13
Is rotating to the left. The passage 30 to which the turning command pressure is supplied has a parallel circuit of a check valve 50 and a throttle 51 on the way, and communicates with the switching valve 52. The passage 53 branched from the passage 30 communicates with the switching valve 52, and the shuttle valve 54 in the middle communicates with the switching valve 29 via the passage 55.

When the control valve 3 is made neutral from the state shown in FIG. 2, the turning command pressure to the passage 30 disappears, but the hydraulic pressure in the passage 30a portion gradually decreases due to the action of the check valve 50 and the throttle 51, and for a while. The switching valve 52 maintains the position shown in FIG. 2, and the hydraulic pressure generated in the main pipe line 6 due to the inertia of the inertial body 14 causes the passage 25, the shuttle valve 26, the passage 27, and the switching valve 5 to move.
2, it acts on the switching valve 29 through the passage 53, the shuttle valve 54, and the passage 55 to keep the switching valve 29 in the state shown in FIG. 2 and hold the brake mechanism B in the released state shown in the figure. When the hydraulic pressure in the main pipeline 6 drops by a certain amount (for example, to 1/3), the passage 30a
The hydraulic pressure of the valve 31 also drops, and the switching valve 52 causes X due to the elasticity of the spring 31.
To the side, and the oil pressure in the passages 53 and 55 disappears,
The switching valve 29 is switched to the X side by the elasticity of the spring 32,
The working chamber 42 communicates with the tank 8 through the passages 40 and 34,
The elastic force of the spring 36 causes the piston 43, the rod 44, and the pad 45 to protrude to the left to brake the output shaft 13.

[0015]

【The invention's effect】

(1) Compared with the conventional swing-back prevention device using hydraulic pressure,
Since the output shaft 13 is held by the mechanical brake mechanism B, the effect is certain. (2) Compared with the conventional swing-back prevention device using hydraulic pressure,
There is no change in performance with temperature. (3) Compared with the conventional swing-back prevention device using hydraulic pressure,
The structure is simple and the reliability is improved. (4) Since the brake mechanism B is made to operate after the driving pressure of the main pipeline 6 has decreased by a certain amount, the capacity of the brake mechanism B may be small, and the device can be compactly and inexpensively assembled.

[Brief description of drawings]

FIG. 1 is a piping diagram showing a first embodiment.

FIG. 2 is a piping diagram showing a second embodiment.

[Explanation of symbols]

 5 Hydraulic Motor 13 Output Shaft 14 Inertial Body 15 Relief Valve 16 Relief Valve 17 Passage 18 Passage B Brake Mechanism

Claims (1)

[Claims] 1. An output shaft is arranged between a hydraulic motor connected to an inertial body and a pair of main pipelines communicating with the hydraulic motor, and opens when the hydraulic pressure of one main pipeline rises above a predetermined value. The relief passage having the relief valve and the hydraulic pressure in the other main pipeline that has been increased by the inertial force of the inertial body after the supply of the hydraulic pressure from the one main pipeline to the hydraulic motor is stopped become a constant pressure by the braking action of the relief valve. An inertial body swing-back prevention device having a brake mechanism that engages with the output shaft of the hydraulic motor after the inertia energy is lost and the pressure in the main pipe line is reduced after being kept.