JPH0741002U - Swing control device - Google Patents

Abstract

(57) [Summary] [Purpose] The swing structure can be selectively switched between the free swing state and the swing constraint state, and the pressure loss during free swing can be reduced to enable complete free swing, and the structure can be downsized. Also, the accuracy of the turning operation is improved. [Configuration] One port 25 or 2 of the hydraulic motor 24
By supplying the hydraulic oil from the pump 21 to 6,
The revolving unit 41 is revolved in the forward direction D1 or the reverse direction D2,
By changing the supply direction and flow rate of the hydraulic oil, the swing operation of the hydraulic motor 24 is controlled by switching to three modes of acceleration, braking and neutral, and driven by the pilot pressure between the swing control valve 29 and the hydraulic motor 24. The swing lock valve 30 is provided. The swivel lock valve 30 has both ports 24 and 25 of the hydraulic motor 24 closed by hydraulic oil in the non-actuated position M3a, and communicates with the swivel control valve 29 in the switch positions M1a and M2a. The pilot pressure of the swing lock valve 29 is controlled by the on / off operation of each electromagnetic switching valve 43, 44.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a turning control device that can be suitably implemented for controlling the turning operation of a crawler crane, for example.

[0002]

[Prior art]

 FIG. 3 is a hydraulic circuit diagram showing a typical prior art swing control device. A revolving structure 1 of a construction machine such as a crawler crane is revolvingly driven by a hydraulic motor 3, and at the time of accelerated revolving, a spool of a revolving control valve 5 provided in a revolving control means 4 is set to a first offset position M1 or a second offset position. By displacing the pilot pressures Pia and Pib in the direction of the position M2 in accordance with the magnitude of the pilot pressures Pia and Pib, the supply direction and the supply amount of the hydraulic oil supplied from the pump 6 to the hydraulic motor 3 are controlled, and The revolving structure 1 is accelerated and revolved in the corresponding revolving direction.

Further, when the spool of the turning control valve 5 is returned to the neutral position M3, the hydraulic oil from the pump 6 is bypassed to the tank 16 through the oil passage 7 and collected, so that the pump 6 does not operate. It becomes a load. Pipe lines 14 and 15 connected to the inlet / outlet ports 3a and 3b of the hydraulic motor 3 communicate with each other, and the revolving structure 1 connected to the hydraulic motor 3 revolves due to inertia. If the amount of oil in the suction side pipeline of the hydraulic motor 3 is insufficient during free swing of the swing body 1, working oil is replenished from the tank 16 via the oil passage 8 and the check valve 17.

In this way, when braking the revolving structure 1 that makes a free revolving motion, the pilot pressure Pi a, Pib to the revolving control valve 5 is applied in the direction in which the hydraulic motor 3 revolves in the direction opposite to the revolving direction. The spool is displaced to guide the hydraulic oil to one port on the discharge side of the hydraulic motor 3 and pressurize it in the opposite direction to control the inertial swing of the swing body 1.

In such a prior art, even when the spool of the swing control valve 5 is set to the neutral position M3, since the braking force does not act on the swing body 1, the swing body 1 cannot be gradually decelerated, and the swing body 1 cannot be gradually decelerated. There is a problem that the turning motion of No. 1 cannot be finely adjusted. Further, even when the swing control valve 5 is neutral, there is a problem that the swing body 1 is swept by an external force such as wind and is displaced undesirably.

In order to solve such a problem, in another prior art, as shown in FIG. 4, relief valves 9 and 10 are provided between the hydraulic motor 3 and the swing control valve 5, and the swing control valve 5 is provided. When the switching valve 11 is switched to neutral, the controlling pressure according to the set pressure of the pilot valve 13 acts on the hydraulic motor 3. However, it is not necessary to apply this braking force. Even if the set pressure of the valves 9 and 10 is lowered, there is a problem that a complete free swing cannot be performed because the pressure loss is large.

Another prior art similar to the prior art shown in FIGS. 3 and 4 is disclosed in Japanese Patent Publication No. 2-4801 (Japanese Patent Laid-Open No. 55-145802). However, similar to the above-described prior art shown in FIG. 4, there is a problem that a complete free swing cannot be performed due to pressure loss during free swing, and a swing control valve and a hydraulic motor for intermediate pressure setting. Between the two relief valves, two pilot valves for switching each set pressure of these relief valves, a switching valve for selecting one of the pilot valves, and a back pressure setting valve. There is a problem that the structure is complicated because a control valve is provided.

[0008]

[Problems to be solved by the device]

 Therefore, an object of the present invention is to provide a turning control device having a simple structure, which selectively releases / restrains the turning motion of a revolving structure and can control the turning motion with high accuracy, and which has improved operability. That is.

[0009]

The present invention has a pressure source and two ports, and one of these two ports is supplied with a working fluid from the pressure source. A fluid pressure motor that swivels the swivel body in the forward direction and that swivels the swivel body in the reverse direction by supplying working fluid from the pressure source to the other port of the two ports. A swirl control device comprising: a swirl control valve for controlling the swirl motion of the fluid pressure motor by changing the supply direction and flow rate of the working fluid supplied from the pressure source to switch among three modes of acceleration, braking and neutral. In the above, a swing lock valve driven by pilot pressure is provided between the swing control valve and the fluid pressure motor, and this swing lock valve closes both ports of the fluid pressure motor in the inoperative position. In the operating position, it is communicated with the swing control valve, and electromagnetic switching valves are provided in the pilot lines on both sides of the swing lock valve, respectively, and the turning motion of the swing structure is controlled by turning on / off each electromagnetic switching valve. A turning control device characterized by selectively switching between a released state and a restrained state.

[0010]

[Action]

 According to the present invention, the working fluid discharged from the pressure source is supplied to the fluid pressure motor through the swing control valve and the swing lock valve, and the working fluid is supplied to the fluid pressure motor depending on the direction and flow rate of the working fluid. The revolving structure is driven to rotate in the forward or reverse direction. The swing lock valve is driven by pilot pressure via two solenoid valves, and by simultaneously turning on / off these solenoid valves, the swing motion of the swing structure is selectively switched between a released state and a restrained state. be able to.

[0011]

【Example】

 FIG. 1 is a hydraulic circuit diagram showing a turning control device according to an embodiment of the present invention. The hydraulic oil in the tank 20 is pumped up by the pump 21, which is a pressure source, and branches from the discharge pipe line 23 to the two main pipe lines 27 and 28 connected to the two ports 25 and 26 of the hydraulic motor 24. Be guided. A swing control valve 29 and a swing lock valve 30 are interposed in these main pipelines 27 and 28. Return pipes 31, 33 are connected between the swing lock valve 30 and the hydraulic motor 24 of the main pipes 27, 28, and relief valves 34, 35 and check valves 36, 35 are connected to the return pipes 31, 33, respectively. 37, and is configured to keep the pressure in the main pipe lines 27, 28 below a set pressure.

The swing control valve 29 is a slide spool type open center type 7 port 3 position switching valve, and the first and second offset positions M 1 and M 1 are controlled by the pilot pressures Pia and Pib through the pilot conduits 38 and 39. A transition is transiently made between M2 and the neutral position M3. The turning control valve 29 communicates the main pipelines 27 and 28 at the neutral position M3.

The swing lock valve 30 is a closed center type 4-port 3-position switching valve of a slide spool type, and pilots via pilot pipe lines 40, 41 connected to the pilot pipe lines 38, 39, respectively. The pressures Pia, Pib transiently switch between the first and second offset positions M1a, M2a and the non-actuated position M3a.

Three-port two-position electromagnetic switching valves 43 and 44 are connected to the pilot conduits 40 and 41, respectively, and a constant pilot pressure Pi ₀ is applied to one of the electromagnetic switching valves 43 by a pilot pipe. It is led via path 45. When the electromagnetic switching valve 43 is excited and switched from the first offset position A1 to the second offset position A2, the pilot pressure Pia is introduced into the pilot chamber 30a of the swing lock valve 30 via the pilot conduit 51. At the same time, the pilot pressure Pia is introduced into the pilot chamber 29a of the turning control valve 29 via the pilot conduit 38.

When the electromagnetic switching valve 43 is in the non-excited state and returns from the second offset position A2 to the first offset position A1, the pilot chamber 30a of the swing lock valve 30 is piloted through the pilot line 51. The pressure Pi ₀ is introduced, and the pilot pressure Pia is introduced into the pilot chamber 29a of the turning control valve 29 via the pilot conduit 38.

Next, regarding the other electromagnetic switching valve 44, when the electromagnetic switching valve 44 is excited and switched from the first offset position B1 to the second offset position B2, the pilot chamber 30b of the swing lock valve 30 is opened. The pilot pressure Pib is introduced through the pilot conduit 41, and the pilot pressure Pib is introduced into the pilot chamber 29b of the turning control valve 29 through the pilot conduit 39.

When the electromagnetic switching valve 44 returns to the first offset position B2 from the second offset position B1 in the non-excited state, the pilot chamber 30b of the swing lock valve 30 has a pilot line 47 and a drain line 47. The pressure is released by the communication with 50, and at the same time, the pilot pressure Pib is introduced into the pilot chamber 29 b of the turning control valve 29 via the pilot conduit 39. The branch line of the discharge line 23 is provided with a relief valve 54 for regulating the maximum pressure of the discharge side line.

The above-mentioned pilot pressures Pia and Pib are controlled by a pilot valve 55 described below, and the configuration thereof will be described below.

FIG. 2 is a hydraulic circuit diagram of the pilot valve 55. The pilot valve 55 has an operating lever 57 that is provided on the support shaft 56 so as to be angularly displaceable, and two pressure reducing valves 58 and 59. The pilot valve 55 controls the pressure of the pressure oil from the pump 60 serving as a pilot pressure source. Arrows C1 and C2 are transiently changed and output according to the amount of angular displacement in the directions, and the pilot pressures Pia and Pib described above can be adjusted.

Next, the operation of the turning control device having the above configuration will be described with reference to Table 1. First, the swinging motion of the swinging body 46 is selectively performed by an operator's operation between a rotation-free state in which the swinging body 46 is rotatable by wind and inertia, and a swinging constraint state in which the swinging motion is restrained according to the operation of the operation lever 57. Is switched to. That is, when the swing free state is selected, the electromagnetic solenoids of the electromagnetic switching valves 43 and 44 are in the non-excited state at the first offset positions A1 and B1, and when the swing restrained state is selected, the excited state is set. Then, it is switched to the second offset positions A2 and B2. In the swing free state (a) and the swing restrained state (b), when the operation lever 57 is in the neutral position (a1), (b1) and when it is operated in the arrow C1 direction (a2). , (B2) and (a3) and (b3) when operated in the arrow C2 direction will be described.

[0021]

[Table 1]

Referring also to FIGS. 1 and 2, when the swing free selection (a) is performed, that is, when the electromagnetic switching valves 43 and 44 are at the first offset positions A1 and B1, one pilot of the swing lock valve 30 is shown. A constant pilot pressure Pi ₀ is applied to the chamber 30a, the other pilot chamber 30b communicates with the return line 31, and the swing lock valve 30 is set to the second offset position M2a. Is neutral (a1), the pilot pressures Pia and Pib are substantially zero, so the turning control valve 29 is set to the neutral position M3. Therefore, the two ports 25, 26 of the hydraulic motor 24 communicate with each other through the main pipes 27, 28, the swing lock valve 30, and the swing control valve 29, and the swing body 46 can swing in either the left or right direction. Be kept free.

When the operator operates the operation lever 57 in the direction of the arrow C1 in the state where the swing lock valve 30 is set to the second offset position M2a in this way (a2), the pilot pressure Pib gradually increases. The turning control valve 29 is switched from the neutral position M3 to the first offset position M1 side in accordance with the operation amount (= the amount of angular displacement in the arrow C1 direction). The hydraulic oil discharged from the pump 21 to the discharge conduit 23 is guided to one port 26 of the hydraulic motor 24 via the swing control valve 29, the swing lock valve 30 at the second offset position M2a, and the main conduit 28. Then, the hydraulic oil is discharged from the other port 25, and the revolving unit 46 revolves in the direction of arrow D1. When the operating lever 57 is operated in the arrow C2 direction (a3), the pilot pressure Pia gradually increases, and the turning control valve 29 is moved to the neutral position according to the operation amount (= the angular displacement amount in the arrow C2 direction). It is switched from M3 to the second offset position M2 side. The hydraulic oil discharged from the pump 21 to the discharge conduit 23 is guided to the other port 25 of the hydraulic motor 24 via the swing control valve 29, the swing lock valve 30 at the second offset position M2a, and the main conduit 27. Then, the hydraulic oil is discharged from the one port 26, and the revolving structure 46 revolves in the direction of arrow D2. In such a turning operation of the turning body 46 in the directions of the arrows D1 and D2, the braking force does not work even if the operation lever 57 is returned to the neutral position, and the turning is continued due to the inertia.

Next, in the rotation restrained state (b), that is, in the state where the electromagnetic switching valves 43 and 44 are switched from the first offset positions A1 and B1 to the second offset positions A2 and B2, the operation lever 57 is set to the neutral position (b1). ), The pilot pressures Pia, Pib are uniformly guided to the pilot chambers 29a, 29b; 30a, 30b of the swing control valve 29 and the swing lock valve 30, respectively, so that the swing control valve 29 is arranged at the neutral position M3. Now, the swing lock valve 30 is arranged at the non-actuated position M3a. At this time, the hydraulic oil discharged from the pump 21 to the discharge pipeline 23 is collected in the tank 49 via the return pipeline 31 and the drain pipeline 48. Since the main pipes 27, 28 of the ports 25, 26 of the hydraulic motor 24 are closed by the swing lock valve 30, the flow of hydraulic oil does not exceed the maximum pressure set in the relief valves 34, 35. As a result, the revolving structure 4 that is restrained as a result and is about to rotate in the direction of the arrow D1 or D2 by an external force such as inertia or wind is braked and locked when it is stationary.

Further, when the operation lever 57 is operated from the neutral position toward the arrow C1 direction in the turning restrained state (b) (b2), the pilot pressure Pib gradually increases, and the turning control valve 29 is increased according to the operation amount. The swing lock valve 30 is switched from the neutral position M3 and the non-actuated position M3a to the first offset positions M1 and M1a. The hydraulic oil discharged from the pump 21 to the discharge conduit 23 is guided to the one port 26 via the flow path of the swing lock valve 30 which is transiently moving from the main conduit 28 to the first offset position M1a. The hydraulic oil discharged from the other port 25 is guided from the main pipe 27 to the return pipe 31 and the drain pipe 48 via the respective passages of the swing lock valve 30 and the swing control valve 29. It is collected in the tank 49. At this time, since the swivel lock valve 30 is transiently displaced, its flow passage cross-sectional area changes according to the magnitude of the pilot pressure Pib, and the flow rate of the hydraulic oil flowing through the main pipe lines 27 and 28 is limited. It Therefore, even if the revolving structure 46 tries to revolve in the direction exceeding the limited flow rate by wind or inertia, for example, in the arrow D1 direction, the pressure becomes low on one port 26 side and the other port 25 side. The pressure increases and braking force is generated. Similarly, even when the operating lever 57 is operated in the direction of arrow C2 (b3), if the revolving structure 46 tries to turn beyond the turning speed intended by the operator, a braking force is generated to cause an undesired result. It is possible to control the turning motion with high accuracy by eliminating the special turning motion.

Although the working oil is used as the working fluid in the above-described embodiment, compressed air may be used as another embodiment of the present invention.

[0027]

[Effect of device]

 As described above, according to the present invention, by switching the electromagnetic switching valve, it is possible to select whether the revolving structure is freely revolved or locked by setting the revolving lock valve in the non-operating or operating position. Further, in free turning, the pressure loss of the hydraulic oil is less than in the above-mentioned prior art, and complete free turning is possible. Further, compared to the above-mentioned prior art, the structure can be downsized, and the swinging motion of the swinging structure can be controlled with high accuracy.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram showing a turning control device according to an embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram of a pilot valve 55.

FIG. 3 is a typical prior art hydraulic circuit diagram.

FIG. 4 is another prior art hydraulic circuit diagram.

[Explanation of symbols]

 21 pump 23 discharge pipe 24 hydraulic motor 25, 26 port 27, 28 main pipe 29 swing control valve 30 swing lock valve 31, 33 return pipe 34, 35 relief valve 43, 44 electromagnetic switching valve 46 swing body 55 pilot valve

Claims (1)

[Scope of utility model registration request] 1. A pressure source and two ports are provided, and a working fluid is supplied from one of these two ports to the working fluid by the pressure source to rotate the revolving unit in a forward direction. And a working fluid supplied from the pressure source, the working fluid being supplied from the pressure source to the other one of the two ports to revolve the revolving structure in the opposite direction. And a flow rate of the fluid pressure motor are changed to control the swing operation of the fluid pressure motor by switching among three modes of acceleration, braking and neutral. A swivel lock valve driven by pilot pressure is provided between the swivel lock valve and the swivel lock valve. The solenoid valve is connected to the control valve, and a solenoid switching valve is provided on each of the pilot lines on both sides of the swing lock valve.
A turning control device characterized in that a turning operation of a turning body is selectively switched between a released state and a restrained state.