JP4108697B2 - Control valve operation device - Google Patents

Description

  The present invention relates to a control valve operating device, and in particular, is suitably used for a crane device that lifts and lowers a suspended load, turns a jib, or lifts and lowers with a driving force generated by a hydraulic motor such as a ship deck crane. About what

  In the conventional crane device, the operator can tilt the operation lever to switch the flow path of the control valve, so that the path of pressure oil supplied to the hydraulic motor that can rotate in two directions is controlled, and Winding, turning of the jib, and elevation are performed (for example, refer to Patent Document 1). In particular, ship deck cranes are required to have a structure that automatically returns the operation lever to the neutral position (position to stop the hydraulic motor) when the operator removes the hand from the operation lever according to the rules of the port where the ship stops. There is.

  There are various means for automatically returning the operation lever to the neutral position, such as a spring back type, an electric control type, and a hydraulic control type. In the spring back type, a coil spring is attached to the rotating shaft of the operating lever, and the operating lever is mechanically returned to the neutral position by a reaction force generated by the coil spring. The electric control type is a method in which the control valve is controlled by a torque motor according to the angle of the operation lever detected by the potentiometer, and the operation lever is electrically returned to the neutral position by the torque generated by the torque motor. is there. The hydraulic control type is a method of returning the operation lever to the neutral position using a hydraulic servo.

Of these methods, the electric control type and hydraulic control type are expensive if they are applied to an existing ship and require a large amount of remodeling work. Therefore, it is practical to use an inexpensive springback type with a simple configuration. It is. A general configuration of a crane apparatus using a springback type is that a spool inserted in a casing of a control valve so as to be vertically slidable is connected to an operation lever via a push-pull cable, and the power for tilting the operation lever is By being transmitted to the spool via the push-bull cable, the spool moves up and down and the pressure oil supply path is controlled. When the operator releases his / her hand from the operating lever, the spool is returned to the neutral position in conjunction with the return of the operating lever to the neutral position by the reaction force of the coil spring that urges the operating lever, and the pressure applied to the hydraulic motor Oil supply is stopped.
JP-A-61-86387

  However, after the operating lever is moved so as to lower the spool, the spool must be lifted against its own weight and returned to the neutral position, so it is necessary to attach a coil spring with a large reaction force to increase the return force. . Then, when the operator tilts the operating lever, a large operating force that overcomes the reaction force of the coil spring is required, so that the lever operation becomes heavy and the operability is impaired.

  Accordingly, an object of the present invention is to provide a structure for automatically returning to a neutral position without increasing the operating force required to tilt the operating lever.

The present invention has been made in view of the circumstances as described above, and the control valve operating device according to the present invention is a control valve operating device in which the flow path of the control valve is switched in conjunction with the operation of the operating lever. The control valve includes a casing having a plurality of ports, a spool inserted in the casing so as to be slidable up and down, and a switching shaft that controls the opening and closing of each port by moving the spool up and down. wherein with the spool is provided with a spring Ru apply a force so as to return to the neutral position, the the switching shaft has a counterweight is provided to resist the weight of the spool, and the center of gravity of the counterweight to the The inclination angle formed by a line connecting the axis of the switching shaft and a horizontal line passing through the axis of the switching shaft is such that the spool is in the upper position or neutral position. Characterized in that it is set to become smaller at the time in the lower position than when in the.

  In this case, since the counterweight that resists the weight of the spool is provided on the switching shaft that moves the spool up and down, the load when the operating lever is tilted to raise the spool to the neutral position is reduced. Therefore, the spring that urges the operating lever to automatically return to the neutral position needs only a small reaction force, and the operating force required for the operator to tilt the operating lever is reduced, improving operability. To do. In addition, the said spring is a concept including what exerts urging | biasing force mechanically besides a coil spring.

Further , the torque generated in the switching shaft by the gravity of the counterweight is larger in the state where the spool is in the lower position than in the state where the spool is in the upper position or the neutral position. That is, the torque is determined by the product of the horizontal distance from the axis of the switching shaft to the center of gravity of the counterweight and the gravity of the counterweight, but the torque increases because the horizontal distance increases when the inclination angle is small. growing. Therefore, it is possible to effectively reduce the operating force of the operating lever required when raising the spool in the lower position to the neutral position.

The center of gravity of the counterweight, the spool may be by Uni set are arranged in a substantially horizontal position relative to the switching shaft in a state in which the lowest point.

  In this way, when the center of gravity of the counterweight is substantially lateral to the switching shaft, the inclination angle is eliminated, and the horizontal distance from the center of the switching shaft to the center of gravity of the counterweight is maximized. Since the torque becomes maximum, the spool at the lowest point where the force required to return to the neutral position is maximum can be raised with a small force.

The counterweight is connected to the switching shaft via an arm, the arm may be made of bent shape.

  In this way, since the arm is bent, one end side of the arm that is connected to the switching shaft can be horizontal in the neutral position regardless of the arrangement of the counterweight, and the mounting angle with respect to the switching shaft can be increased. It becomes easy to fix with accuracy.

  The spool may be raised when the operation lever is tilted toward the front side where the cockpit is located, while the spool may be lowered when the operation lever is tilted to the opposite side.

  In this way, the operating lever is pulled when the spool that requires a large operating force is raised, so that the operator can easily apply force and the operating efficiency is improved. In other words, it is difficult for the operator to push the operation lever away from the body, for example, when it is sitting in the cockpit, but it is difficult to apply force when the operator is sitting on the cockpit. Easy and operability is improved.

  Upper and lower drain ports may be provided on the upper and lower wall surfaces of the casing above the spool, respectively, and connected to the oil tank via the discharge pipe.

  In this way, when the spool slides upward, the pressure oil above the spool is returned from the upper drain port to the oil tank by the stroke, while when the spool slides downward, the pressure below the spool is returned. Oil is returned to the oil tank from the lower drain port for the stroke. At that time, since the drain pipe connected to the oil tank is provided separately for each of the upper drain port and the lower drain port, they are connected by a bypass line and connected to the oil tank by one drain pipe As compared with the above, the resistance of the pressure oil can be reduced.

As is apparent from the above description, according to the present invention, since the counterweight is provided against the weight of the spool, the load required to tilt the operation lever and raise the spool from the lower position to the neutral position. Is reduced. Therefore, it is not necessary to increase the reaction force of the spring that urges the operation lever to automatically return to the neutral position, and the operation force required when the operator tilts the operation lever is reduced and the operability is improved. Further, the torque generated in the switching shaft by the gravity of the counterweight is larger in the state where the spool is in the lower position than in the state where the spool is in the upper position or the neutral position. That is, the torque is determined by the product of the horizontal distance from the axis of the switching shaft to the center of gravity of the counterweight and the gravity of the counterweight, but the torque increases because the horizontal distance increases when the inclination angle is small. growing. Therefore, it is possible to effectively reduce the operating force of the operating lever required when raising the spool in the lower position to the neutral position.

  Embodiments according to the present invention will be described below with reference to the drawings.

  FIG. 1 is an overall view of a crane device 1 including a control valve operating device 100 according to the first embodiment. In the crane apparatus 1, a house 5 is erected on a fixed post 3 protruding from a ship deck 2 via a rotary bearing unit 4. A jib 6 is attached to the house 5 so as to be able to be lifted and a wire 8 having a hook is wound around a pulley 7 provided at the tip of the jib 6. The rear end side of the wire 8 is wound around a winding / lowering drum 10, and a wire 9 connected to the tip of the jib 6 is wound around a lifting drum 11.

  The hoisting / lowering drum 10 is connected to a hoisting / lowering hydraulic motor 12 having a pair of ports and capable of rotating in two directions. The lifting drum 11 is connected to a lifting hydraulic motor 13 having a pair of ports and capable of rotating in two directions. The rotary bearing unit 4 is connected with a turning hydraulic motor 14 having a pair of ports and capable of rotating in two directions. Control valves 15 to 17 that control the rotational direction and speed of the hydraulic motors 12 to 14 by switching the paths of the pressure oil supplied to the ports of the hydraulic motors 12 to 14 are provided to the hydraulic motors 12 to 14 provided in the house 5. Is connected. Hydraulic pumps 18 to 20 and an oil tank T are connected to each port of the control valves 15 to 17 and one end sides of push-pull cables 21 to 23 that transmit power for switching the flow path are connected. The other end side of the push-pull cables 21 to 23 is connected to an operation lever 65 (only for winding and unwinding) in an operation stand 61 disposed opposite to a cockpit 72 in a cab 60 attached to the house 5. It is connected to a mounting piece 70 projecting laterally from the rotating shaft 64. In addition, since each control valve 15-17 for hoisting / lowering, raising / lowering and turning, each push-pull cable 21-23, etc. are mutually the same structures, the following is representative about the thing for hoisting / lowering explain.

  2A is a sectional view of the control valve 15 of the crane apparatus 1 as viewed from above, and FIG. 2B is a sectional view as viewed from the side. As shown in FIGS. 2A and 2B, the control valve 15 has a casing composed of a casing body 24, a lower cover 25, and an upper cover 26, and the internal space 27 and the lower cover 25 of the casing body 24. A spool 30 is inserted into an internal flow path formed by communicating the internal space 28 and the internal space 29 of the upper cover 26 so as to be vertically slidable. The upper cover 26 above the spool 30 is provided with an upper drain port 50 to which a discharge pipe 73 communicating with the tank T is connected. The lower cover 25 below the spool 30 is provided with a lower drain port 51 to which a separate discharge pipe 74 communicating with the tank T is connected.

  On the wall surface facing the internal flow path 27 of the casing body 24, first to fourth annular recesses 31, 33, 35, and 37 are recessed in order from above. A first port 32 connected to the forward rotation port of the hydraulic motor 12 communicates with the first annular recess 31. A second port 34 connected to the discharge port of the hydraulic pump 18 is communicated with the second annular recess 33. A third port 36 connected to the reverse rotation port of the hydraulic motor 12 communicates with the third annular recess 35. A fourth port 38 connected to the oil tank T is communicated with the fourth annular recess 37.

  The outer surface of the spool 30 is provided with a first annular groove 39 that faces the first annular recess 31 and a second annular groove 40 that faces the third annular recess 35 when the spool 30 is in the neutral position. A bypass channel 41 is formed in the spool 30 in the vertical direction. The spool 30 is provided with a first through hole 42 that allows the bypass passage 41 and the first annular groove 39 to communicate with each other, and the spool 30 is located below the fourth annular recess 37 in the neutral position. A second through-hole 43 that communicates the outer surface with the bypass channel 41 is provided.

  A horizontal switching shaft 44 is rotatably passed through the upper cover 26, and a ball joint 48 protrudes laterally at an intermediate position of the switching shaft 44, and this ball joint 48 is connected to the upper side surface of the spool 30. Is rotatably fitted in a recess 49 provided in the housing. That is, as the switching shaft 44 rotates, the spool 30 slides up and down. A metal bush 45 is interposed between the switching shaft 44 and the upper cover 26. A rubber oil seal 47 having a U-shaped cross section is interposed between the switching shaft 44 and a mounting member 46 attached to the upper cover 26 from both axial sides of the switching shaft 44.

  A link arm 54 protruding upward is connected to one end side of the switching shaft 44 protruding from the upper cover 26, and one end of the cable rod 21 b of the push-pull cable 21 is connected to the upper portion of the link arm 54 via the link member 55. It is connected. The outer cylinder member 21 a that covers the cable rod 21 b that advances and retreats is positioned and held by a holding portion 57 a of the cable support member 57 that is fixed to the upper cover 26. On the other hand, one end side of the bent arm 52 is fastened and fixed to the other end side of the switching shaft 44 protruding from the upper cover 26 with a bolt, and the other end side of the arm 52 is a counter weight 53 that is a substantially rectangular parallelepiped. It is fixed to the upper surface with bolts B so that the gravity of the counterweight 53 resists the weight of the spool 30. Here, one end of the arm 52 that is connected to the switching shaft 44 is horizontal at the neutral position and is perpendicular to the link arm 55.

  FIG. 3 is an explanatory view showing the movement of the counterweight 53 of the crane apparatus 1. The center of gravity G of the counterweight 53 is set so as to be positioned on the side in the substantially horizontal direction with respect to the axis C of the switching shaft 44 when the spool 30 is at the lowest point. In other words, the inclination angle θ formed by the line A connecting the center of gravity G of the counterweight 53 and the axis C of the switching shaft 44 and the horizontal line H passing through the axis C of the switching shaft 44 is the spool 30 in the upper position or neutral position. It is set to be smaller when it is in the lower position than when it is in the position. Specifically, the inclination angle θ is about 0 ° when the spool 30 is below the lowest point, the inclination angle θ is about 34 ° when the spool 30 is at the neutral position, and the inclination angle when the spool 30 is above the uppermost point. θ is about 68 °.

  As shown in FIG. 2, the “lower position” means that the spool 30 moves downward in the casing and the second port 34 communicating with the hydraulic pump 18 is connected to the second annular recess 33 and the first annular groove. 39 is a state in which pressure oil is communicated with the first port 32 via 39 and supplied to the port on the positive rotation side of the hydraulic motor 12. “Upper position” means that the spool 30 moves upward in the casing and the second port 34 communicating with the hydraulic pump 18 is connected to the third port 36 via the second annular recess 33 and the second annular groove 40. This is a state in which pressure oil is supplied to the port on the reverse rotation side of the hydraulic motor 12. The “neutral position” refers to a state in which the spool 30 is located between the upper position and the lower position and is stopped without being supplied with hydraulic oil from the hydraulic pump 18 to the hydraulic motor 12.

  FIG. 4A is a cross-sectional view of the operation stand 61 of the crane apparatus 1, and FIG. 4B is a cross-sectional view seen from a direction different by 90 °. The operation stand 61 has a rotating shaft 64 that is rotatably supported by bearings 62 and 63 on an inner cylinder portion 61b that projects downward from the upper wall of the stand case 61a. An operation lever 65 protruding upward is fixed to the rotating shaft 64, and a bellows-like rubber-like cylindrical protective material 66 is provided at an intermediate portion of the operation lever 65 so as to cover the upper opening of the inner cylinder portion 61b. It has been. A mounting piece 70 that protrudes away from the cockpit 72 of the cab 60 is fixed to the rotating shaft 64 (see FIGS. 1 and 4B). The other end of the cable rod 21 b of the push-pull cable 21 is connected to the tip of the mounting piece 70 via a link member 71. The outer cylindrical member 21a of the push-pull cable 21 is positioned and fixed to the bottom wall 61c of the stand case 61a by a fixing portion 21c such as a nut portion.

  At one end side of the rotating shaft 64, a cylindrical body 68 fitted with a coil spring 69 is fixed to the stand case 61a. One end of the coil spring 69 is connected to the inner cylinder part 61b via an arm (not shown), while the other end of the coil spring 69 is connected to the mounting piece 70 via an arm (not shown). The coil spring 69 automatically balances the spool 30 and the operation lever 65 to the neutral position by balancing the spool 30 and the counterweight 53 via the push-pull cable 21 when the operator releases the operation lever 65. Energized to return.

  Next, the action of the counterweight 53 accompanying the change in the position of the spool 30 will be described with reference to FIG. The torque generated in the switching shaft 44 by the counter weight 53 is determined by the product of the horizontal distance from the axis C of the switching shaft 44 to the center of gravity G of the counter weight 53 and the gravity M of the counter weight 53.

Therefore, when the horizontal distance from the axis C of the switching shaft 44 in the spool under position to the center of gravity G of the counterweight 53 L1, the weight of the counterweight 53 is M, the torque T _D at the spool under position is L1 · M . Also, when the horizontal distance from the axis C of the switching shaft 44 in the spool neutral position to the center of gravity G of the counterweight 53 and L2 (= L1 · cosθ), the torque _{T N} at the spool neutral position is L2 · M. Also, when the horizontal distance from the axis C of the switching shaft 44 in the spool on the position to the center of gravity G of the counterweight 53 and L3 (= L1 · cos2θ), the torque _{T U} in the spool on position is L3 · M.

That is, since L1>L2> L3, the relationship of T _D > T _N > T _U is established, and the torque when the spool 30 is returned from the lower position to the neutral position becomes the largest, against the weight of the spool 30. The reaction force of the coil spring 69 for returning to the neutral position can be small. Meanwhile, when to return to the neutral position the spool 30 from the upper position is better torque is small due to a counterweight 53 for utilizing the weight of the spool 30 in the reverse, the torque T _U at that time most like the Because it is small, it contributes to a smooth return to the neutral position.

  As is clear from the above description, since the counterweight 53 against the weight of the spool 30 is provided on the switching shaft 44 of the control valve 15, the weight of the spool 30 is canceled and the operation lever 65 is tilted to cancel the spool. The load when raising 30 from the lower position to the neutral position is reduced. Accordingly, the coil spring 69 that urges the operation lever 65 to automatically return to the neutral position has a small reaction force, and the operation force required when the operator tilts the operation lever 65 can be reduced. The inclination angle θ formed by the line A connecting the center of gravity G of the counterweight 53 and the axis C of the switching shaft 44 and the horizontal line H passing through the axis C of the switching shaft 44 is most when the spool 30 is in the lower position. Since it is set to be small, it is possible to effectively reduce the operating force of the operating lever 65 required to raise the spool 30 at the lower position to the neutral position.

  Further, the protruding direction of the attachment piece 70 is set to be away from the cockpit 70 so that the spool 30 is raised when the operator sitting on the cockpit 72 tilts the operation lever 65 toward the front side. When the spool that requires force is raised, the operator can easily apply force and the operability is improved. Further, an upper drain port 50 and a lower drain port 51 are provided above and below the spool 30 of the control valve 15, respectively, and are connected to the oil tank T via separate discharge pipes (not shown). The resistance of the pressure oil when the spool 30 is moved up and down can be reduced. In the present embodiment, the coil spring 69 is used as a spring, but other types of springs may be used as long as the operation lever 65 is dynamically biased to the neutral position. Moreover, although this embodiment demonstrated the crane apparatus, as long as the spool inserted in the control valve is moved up and down with an operation lever, you may apply to another apparatus.

  Next, a second embodiment will be described. FIG. 5 is an explanatory view showing the movement of the counterweight 53 of the second embodiment. As shown in FIG. 5, in the second embodiment, the arm 80 is arranged so that the line connecting the center of gravity G of the counterweight 53 and the axis C of the switching shaft 44 coincides with the horizontal line H while the spool 30 is in the neutral position. Is linear.

When the horizontal distance from the axis C of the switching shaft 44 to the gravity center G of the counterweight 53 at the spool neutral position is L1, and the weight of the counterweight 53 is M, the torque _{TN at the} spool neutral position is L1 · M. Also, when the horizontal distance from the axis C of the switching shaft 44 in the spool under position to the center of gravity G of the counterweight 53 and L2 (= L1 · cosθ), the torque _{T D} at the spool under position is L2 · M. Further, since the horizontal distance from the axis C of the switching shaft 44 in the spool on the position to the center of gravity G of the counterweight 53 is also L2 (= L1 · cos2θ), the torque _{T U} in the spool on position is L2 · M. That is, since L1> L2, the relationship of T _N > T _D = T _U is established, and the torque when the spool 30 is in the neutral position is the largest. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

FIG. 6 is a graph showing the relationship between the torque by the counterweight and the spool position, comparing the first embodiment and the second embodiment. As shown in FIG. 6, the torque T _D in the torque is most needed by the counterweight 53 against the weight of the spool 30 "down position", the direction of the first embodiment is larger than the second embodiment Yes. On the other hand, T _U in is most required torque by the counterweight 53 "up position" better in the first embodiment is smaller than the second embodiment.

  As described above, the control valve operating device according to the present invention is excellent in that the operating force required to tilt the operating lever can be reduced while adopting a structure in which the operating lever is automatically returned to the neutral position by the spring. It has an effect and is suitable for application to, for example, a crane device.

1 is an overall view of a crane device including a control valve operating device according to a first embodiment of the present invention. (A) is sectional drawing which looked at the control valve of the control valve operating device of FIG. 1 from the top, (b) is sectional drawing seen from the side. It is explanatory drawing which shows the motion of the counterweight of the control valve operation apparatus of FIG. (A) is sectional drawing of the operation stand of the control valve operating device of FIG. 1, (b) is sectional drawing seen from the direction which differs 90 degrees. It is explanatory drawing which shows the motion of the counterweight of 2nd Embodiment. It is a graph which shows the relationship between the torque by the counterweight which compared 1st Embodiment and 2nd Embodiment, and a spool position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crane apparatus 12-14 Hydraulic motor 15-17 Control valve 18-20 Hydraulic pump 21-23 Push pull cable 24 Casing main body 25 Lower cover 26 Upper cover 30 Spool 32, 34, 36, 38 1st-4th port 44 switching Shaft 45 Metal bush 47 Oil seal 48 Ball joint 50 Upper drain port 51 Lower drain port 52 Arm 53 Counterweight 57 Cable support 64 Rotating shaft 65 Operation lever 69 Coil spring (spring)
70 Mounting pieces 73, 74 Discharge pipe 100 Control valve operating device θ Inclination angle

Claims (5)

In the control valve operating device that switches the flow path of the control valve in conjunction with the operation of the operating lever,
The control valve includes a casing having a plurality of ports, a spool inserted in the casing so as to be slidable up and down, and a switching shaft that controls the opening and closing of each port by moving the spool up and down,
Together with the said operating lever said spool is provided with spring Ru apply a force so as to return to the neutral position, the the switching shaft has a counterweight is provided to resist the weight of the spool,
An inclination angle formed by a line connecting the center of gravity of the counterweight and the axis of the switching shaft and a horizontal line passing through the axis of the switching shaft is lower than when the spool is in the upper position or the neutral position. A control valve operating device which is set to be smaller at a certain time . The center of gravity of the counterweight, the spool control valve operating device according to claim 1, which is by Uni set are arranged in a substantially horizontal position relative to the switching shaft in a state in which the lowest point. The counterweight is connected to the switching shaft via an arm, said arm control valve operating device according to claim 1 or 2 consisting of bent shape. The one in which operating lever the spool to be inclined to the front side with a cockpit rises, one said operating lever said spool and is tilted to the opposite side of claims 1 to 3 has a configuration in which drops A control valve operating device according to claim 1. Said spool from upper and lower walls of the casing, upper drain port and lower drain port are provided respectively, the control according to any one of claims 1 to 4 is connected to the oil tank via respective discharge pipes Valve operating device.

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