JPH06247692A - Turn braking device for working vehicle with boom - Google Patents

Abstract

PURPOSE:To set a turning hydraulic motor to the nonoperational state in a turn braking area and miniaturize a braking means by providing a valve means opened based on the output of a turn area entry detection section on a bypass oil path connecting a pair of feed/discharge oil paths of the turning hydraulic motor. CONSTITUTION:The discharge oil is fed to a turning hydraulic motor 1 from a hydraulic pump 3 via a turn control valve 2, a pinion gear is rotated by the generated power via reduction gears 1a to rotate a rotary base B, and a braking means 5 is operated at the time of braking. A bypass oil path 13 connecting a pair of feed/discharge oil paths of the turning hydraulic motor 1 is provided, and a valve means 14 is provided in the middle. The valve means 14 is normally located at the limiting position limiting the flow of the operating oil passing through the bypass oil path 13, however it is switched to the nonlimiting position by a switching signal output section 15 when a braking area entry detection section 10 detects that the rotary base B enters the braking area, and the turning hydraulic motor 1 is switched to the nonoperational state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-way three-position swivel control valve in which a swivel having a boom is mounted on a vehicle so that the swivel is freely rotatable and the drive of a hydraulic motor for swiveling the swivel is controlled. The present invention relates to a swing braking device used in a work vehicle having a boom which is operated by a swing operation lever mechanically connected to the swing control valve.

[0002]

2. Description of the Related Art As a work vehicle having a boom, there are a mobile crane, an aerial work vehicle and the like. FIG. 2 shows a mobile crane as a work vehicle having a boom. In FIG. 2, the mobile crane is configured such that a swivel B mounted on the vehicle A so as to swivel freely, a boom C attached to the swivel B so that the hoisting can be driven, and a hoisting device hung at the tip of the boom C is hoisted and wound. It is equipped with a winch D that is driven downward. The swing drive of the swivel base B, the raising / lowering drive of the boom C, the extension / contraction drive of the boom C, and the hoisting / lowering drive of the winch D are driven by a turning hydraulic motor, a hoisting cylinder, and a winch motor, respectively. ing.

FIG. 4 shows a hydraulic circuit for driving a turning hydraulic motor. In FIG. 4, reference numeral 1 is a turning hydraulic motor, and the turning hydraulic motor 1 is supplied with oil discharged from a hydraulic pump 3 through a four-way three-position turning control valve 2. ing. Reference numeral 4 denotes an operation lever for operating the turning control valve 2, which is mechanically connected to the turning control valve 2.

In the work vehicle having the boom constructed as described above, since the boom C does not collide with a building or the work vehicle does not fall, the turning stop position of the swivel base B (allowable turning limit) as shown in FIG. Positions) ΘL1 and ΘL2 are present. In FIG. 3, the turning stop position ΘL1 is a stopping position when the swivel base B is driven to rotate right, and the turning stop position θL2 is a stopping position when the swivel B is driven to rotate left.
Therefore, in a work vehicle having a boom of this kind, the swinging motion of the swivel base B is automatically braked in the swing braking region ΘB1 to ΘL1 or ΘB2 to ΘL2 before the swing stop position ΘL1 or ΘL2, and the swing stop position is set. A swing braking device for stopping at ΘL1 or ΘL2 is attached.

Next, a swing braking device for a conventional work vehicle having a boom will be described with reference to FIG. In FIG. 4, the swing braking device is a friction type brake means 5 driven by a brake driving means 5a to brake the swing motion of the swivel base B, a swivel speed detector 6 for detecting an actual swivel speed ΘV0 of the swivel base B, A signal from the turning position detector that detects the actual turning position Θ of the turntable B, and the signals from the turning speed detector 6 and the turning position detector 7 is received and arithmetically calculated to perform brake control on the brake driving means 5a. And a control signal output means 8 for outputting a signal.

In FIG. 4, the driving force of the turning hydraulic motor 1 is a turning mechanism (composed of a ring gear attached to the vehicle A side and a pinion gear meshing with the ring gear) via a speed reducer 1a. It is designed to drive the pinion gear of. Then, the braking means 5 is
It is attached to the input shaft side of the speed reducer 1a. The brake drive means 5a for driving the brake means 5 is composed of a hydraulic actuator 5b for driving the brake means 5 and an electromagnetic proportional valve 5c for controlling the supply / discharge of pressure oil to / from the hydraulic actuator 5b. The turning speed detector 6
Is a rotary encoder mounted on the input shaft side of the speed reducer 1a. The turning position detector 7 is composed of a rotary potentiometer.

The control signal output means 8 is composed of a turning braking area signal output section 9, a braking area entry detection section 10, a target turning speed signal output section 11, and a braking signal output section 12. . The swing braking area signal output unit 9 outputs a swing braking area signal regarding the swing braking areas ΘB1 to ΘL1 and ΘB2 to ΘL2 set before the swing stop positions ΘL1 and ΘL2 at which the swing motion of the swivel base B should be stopped. is there. The braking area entry detection unit 10 outputs a turning braking area signal ΘB1 from the turning braking area signal output unit 9.
~ ΘL1 and ΘB2 to ΘL2 and the turning position detector 7
Based on the actual turning position Θ signal from, the actual turning position Θ is the turning braking area ΘB1 to ΘL1 or ΘB2 to ΘL2.
Is detected and the braking area entry signal b is output.

Based on the signals from the turning braking area signal output section 9, the braking area entrance detection section 10, and the turning speed detector 6, the target turning speed signal output section 11 is controlled by the braking area entrance detection section 10. Time-varying target turning for decelerating the turning speed ΘV0 of the turntable when the braking area entry signal b is output in the turning braking areas ΘB1 to ΘL1 or ΘB2 to ΘL2 and stopping at the end of the turning braking area It outputs the speed ΘVP. The brake signal output unit 12 is
Target turning speed ΘVP from the target turning speed output unit 11
And the actual turning speed ΘV0 from the turning speed detector 6.
Based on, the actual turning speed ΘV0 is the target turning speed ΘVP
To output the brake control signal to the brake control means 5a.

In the conventional swing braking device having such a structure, the swing control valve 2 is operated in the forward or reverse direction from the neutral position by the operating lever 4 to drive the swing hydraulic motor 1 and the swing base B is moved forward. When the turning position of the turntable B reaches the turning braking area [Theta] B1 to [Theta] L1 or [Theta] B2 to [Theta] L2 set before the turning stop position [Theta] L1 or [Theta] L2, in the state where the turning drive is performed in the forward or reverse direction. A brake signal is output from the brake signal output unit 12 in the above, and the brake means 5 is driven by this brake signal to brake the turning speed of the turntable B in the turning braking area and automatically at the end of the turning braking area. Since it can be stopped, it is extremely effective in ensuring the safety of the work vehicle having a boom.

However, in the above-described conventional turning braking apparatus for a work vehicle having a boom, the turning hydraulic motor 1 is driven even when the braking means 5 is driven by the brake signal from the control signal output means 8. However, there is a problem in that the braking means 5 must have a large braking ability. That is, the braking means 5
Operates in a state where the swing control valve 2 is operated in the forward direction or the reverse direction from the neutral position by the operation lever 4 to drive the swing hydraulic motor 1, so that the inertial force of the swing base B and the swing motion This is because it is necessary to brake the swing motion of the swivel base B against the driving force of the hydraulic motor 1 as described above.

[0011]

SUMMARY OF THE INVENTION The present invention solves the problems of the conventional swing braking device described above, and when the brake means 5 is driven to brake the swing motion of the swivel base B, the swing hydraulic pressure is used. An object of the present invention is to provide a swing braking device for a work vehicle having a novel boom in which the motor 1 is automatically brought into a non-driving state.

[0012]

In order to achieve the above object, a swing braking device for a work vehicle having a boom according to the present invention is provided.
The following structure is added to the above-described conventional swing braking device. That is, a pair of oil supply / exhaust passages of the turning hydraulic motor 1 are connected by a bypass oil passage, and the bypass oil passage is always in a regulating position for regulating the flow of hydraulic oil between the both oil supply / exhaust passages. A valve means that is switched to an unrestricted position that does not restrict the flow of the hydraulic oil between the oil supply and discharge oil passages by a switching signal is provided, and the control signal output means 8 is braked by the braking area entrance detection unit 10. A switching signal output section for receiving a region entry signal and outputting a switching signal to the valve means is attached.

[0013]

In the swing braking apparatus for a work vehicle having the boom of the present invention constructed as described above, the valve means is switched to the non-restricted position when the swivel base B swings to enter the swing braking area. Even if 2 is in the operation position, no driving force is generated in the swing hydraulic motor 1. Therefore, the braking means 5 having a relatively small braking ability is sufficient.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a swing braking device for a work vehicle having a boom according to the present invention will be described below with reference to FIG. Since the swing braking device for a work vehicle having a boom of the present invention is a structure in which a part is added to a conventional fiber or braking device, the reference numerals used in the above description of the prior art have the same meanings in the following description. Incorporated as a thing. In FIG. 1, 13
Is a bypass oil passage that connects between a pair of supply and discharge oil passages of the turning hydraulic motor. Valve means 14 is interposed in the bypass oil passage 13. The valve means 14 is normally located at a limiting position (position in FIG. 1) that limits the flow of hydraulic oil passing through the bypass oil passage 13, and controls the flow of hydraulic oil passing through the bypass oil passage by a switching signal described later. It can be switched to a non-restricted position without restriction. In the state where the valve means 14 is switched to the non-restricted position, the hydraulic oil bypasses through the bypass oil passage 13 even if the swing control valve 2 is switched from the neutral position to the forward direction or the reverse direction. No driving force is generated in No. 1.

In this embodiment, the valve means 14 comprises a balance piston type relief valve 14a installed in the bypass oil passage 13 and a normally closed electromagnetic on-off valve installed in the vent oil passage of the relief valve 14a. And 14b.
The electromagnetic opening / closing valve 14b is designed to be switched to the open position by a switching signal described later. When the electromagnetic opening / closing valve 14b is closed, the set pressure of the relief valve 14a is
The pressure is sufficient to generate a sufficient driving force for the swing hydraulic motor 1, and the valve means 14 is in the limit position. Further, in a state where the electromagnetic opening / closing valve 14b is switched by the switching signal described later, the set pressure of the relief valve 14a is set to a low pressure, and the valve means 14 is in the non-restricted position.

Reference numeral 15 is a switching signal output section provided in the control signal output means 8. The switching signal output section 15 outputs the switching signal for switching the valve means 14 to the non-restricted position when receiving the braking area entry signal from the braking area entry detection section 9.

Next, the operation will be described. The braking means 5 in the swing braking device for a work vehicle having a boom according to the present invention comprises:
The control signal output means 8 operates in response to a brake signal from the brake signal output section 12 to brake the swing motion of the swivel base B in the swing braking areas ΘB1 to ΘL1 or ΘB2 to ΘL2 to terminate the swing braking area (turning stop). Position ΘL1 or Θ
The function of stopping at L2) is similar to the conventional one. The valve means 14 in the swing braking device of the present invention is switched to the non-restricted position by the braking area entry signal from the braking area entry detection unit 9, and the turning hydraulic motor 1 is operated.
Since the flow of the hydraulic oil in the bypass oil passage 13 that connects both the oil supply and discharge oil passages is free, the swivel base B enters the swing braking region and the brake means 5 starts to operate, and at the same time, the swing hydraulic motor 1 That is, the driving force is not generated.

Therefore, in the swing braking device for a work vehicle having a boom according to the present invention, the braking means 5 can have a braking ability smaller than that of the conventional braking means.

[0019]

[Effects] The swing braking device for a work vehicle having a boom of the present invention configured and operated as described above has a simple structure in which only a part of the structure is added to the conventional swing braking device, but the braking of the braking means 5 is performed. Ability can be small,
The device can be made compact accordingly.

[Brief description of drawings]

FIG. 1 is an explanatory view of a swing braking device for a work vehicle having a boom according to the present invention.

FIG. 2 is an explanatory diagram of a work vehicle having a boom.

FIG. 3 is an explanatory diagram of a turning stop position and a turning braking area of a work vehicle having a boom.

FIG. 4 is an explanatory diagram of a swing braking device for a work vehicle having a conventional boom.

[Explanation of symbols]

1; Swing hydraulic motor, 2; Swing control valve, 3; Hydraulic pump, 4; Operating lever, 5; Brake means, 5a; Brake drive means, 5b; Electromagnetic proportional valve, 5c; Hydraulic actuator, 6; Swing speed detector , 7; turning position detector, 8;
Control signal output means, 9; turning braking area signal output section, 1
0: braking area entry detection unit, 11: target turning speed signal output unit, 12: brake signal output unit, 13: bypass oil passage,
14; valve means, 15; switching signal output section,

Claims (1)

[Claims] 1. A four-way three-position swivel control valve which mounts a swivel base equipped with a boom on a vehicle in a freely rotatable manner, and which controls the drive of a hydraulic motor for swiveling the swivel base. A swing braking device for use in a work vehicle having a boom configured to be operated by a swing operation lever mechanically connected to: a friction that is driven by a brake drive means to brake the swing motion of the swivel base. -Type braking means, a swing speed detector that detects the swing speed of the swivel base, a swing position detector that detects the actual swing position of the swivel base, and from the swing speed detector and the swing position detector Control signal output means for receiving the signal of the above, calculating and calculating, and outputting a brake control signal to the brake drive means, the control signal output means: A turning braking area signal output unit that outputs a turning braking area signal related to the turning braking area set before the turning stop position, the turning braking area signal from the turning braking area signal output unit and the signal from the turning position detector. Based on this, a braking area entry detection unit that detects that the actual turning position has reached the turning braking area and outputs a braking area entry signal, the turning braking area signal output unit, the braking area entry detection unit, And, based on the signal from the turning speed detector, the turning speed of the swivel base when the braking area entry detection unit outputs the braking area entry signal is decelerated in the turning braking area and stopped at the end of the turning braking area. A target turning speed signal output unit for outputting a target turning speed that changes with time, based on the target turning speed from the target turning speed output unit and the actual turning speed from the turning speed detector. Brake signal output unit for outputting a brake control signal to the brake control means so that the actual rotation speed reaches the target turning velocity,
A pair of supply and discharge oil passages of the turning hydraulic motor are connected by a bypass oil passage, and the flow of the working oil between the supply and discharge oil passages is always connected to the bypass oil passage. Is provided in a restriction position for restricting the flow of hydraulic oil between the two oil supply and discharge oil passages by a switching signal, and a valve means for switching to a non-regulation position for not restricting the flow of hydraulic oil is provided. A swing braking apparatus for a work vehicle having a boom, comprising a switching signal output section for receiving a braking area entry signal from a detection section and outputting a switching signal to the valve means.