JP2013007476A - Hydraulic machine and deck crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve finer speed switching than the prior art in the case of driving a drive object by a plurality of hydraulic motors axially coupled in parallel to the drive object.SOLUTION: This hydraulic machine A is adapted to control speed by switching the number of chambers to be supplied with a hydraulic fluid according to the load of a winding winch regarding the first and second hydraulic motors 5, 6 having a plurality of chambers 5a-5c, 6a-6c and axially coupled in parallel to the winding winch. The number of chambers to be supplied with the hydraulic fluid is allowed to differ between the first and second hydraulic motors 5, 6.

Description

  The present invention relates to a hydraulic machine and a deck crane.

  Some deck cranes drive a winch using two vane type hydraulic motors. In the vane type hydraulic motor, as is well known, a plurality of plate-like members called vanes are vertically mounted on the circumferential surface of the rotor, and hydraulic oil is supplied between the casing housing the rotor and the rotor. The hydraulic motor is provided with a plurality of chambers. In such a vane type hydraulic motor, the rotation speed is switched according to the number of chambers (hereinafter referred to as “the number of oil supply chambers”) to which hydraulic oil is supplied. The deck crane is provided with two such vane type hydraulic motors in parallel with the winch. The winding speed of the winch can be increased by varying the number of oil supply chambers for each vane type hydraulic motor. Switch. For example, Patent Document 1 below discloses a deck crane in which a winch is driven by two hydraulic motors and a winch hoisting rotational speed is switched in three stages according to a load.

JP 2002-220189 A

  In the above prior art, the number of oil supply chambers is the same for the two vane type hydraulic motors. That is, in the conventional deck crane, the number of oil supply chambers is switched to three patterns for one vane type hydraulic motor, one case, two cases, and three cases. As a result, the winding speed of the winch is increased. Switch to 3 steps (3 patterns).

  However, since the number of switching is small in the switching of the three-stage hoisting rotational speed, there may be a loss in the efficiency of the cargo handling work depending on the weight of the load (the load on the winch). There is a demand for more efficient cargo handling work by switching the rotation speed. As a method of easily increasing the number of winch hoisting rotation speeds to be switched, for example, it is possible to easily increase the number of chambers of a vane type hydraulic motor. However, in this case, the cost of the hydraulic motor greatly increases. It is not preferable.

  The present invention has been made in view of the above-described circumstances, and realizes speed switching that is finer than conventional methods when a drive target is driven by a plurality of hydraulic motors that are axially coupled to the drive target in parallel. Objective.

  In order to achieve the above object, according to the present invention, as a first solving means related to a hydraulic machine, hydraulic oil is supplied to a plurality of hydraulic motors that are provided with a plurality of chambers and that are axially coupled to a driven object in parallel. A hydraulic machine that performs speed control by switching the number of chambers according to a load, and adopts a means that allows the number of chambers that supply hydraulic oil to be different among hydraulic motors.

  In the present invention, as the second solving means relating to the hydraulic machine, in the first solving means, the number of chambers for supplying the hydraulic oil is changed one by one in a specific order according to the load for the plurality of hydraulic motors. , Is adopted.

  In the present invention, as a third solving means relating to the hydraulic machine, in the first or second solving means, the fluctuation range of the load is divided into a plurality of small areas, and each hydraulic motor is divided into a small area where the load is minimum. Then, a means is adopted in which hydraulic oil is supplied to each one chamber, and the number of chambers to which the hydraulic oil is supplied is changed one by one in a specific order according to the load.

  In the present invention, as a fourth solving means relating to the hydraulic machine, in any one of the first to third solving means described above, the hydraulic oil is supplied to the chambers excluding at least one of the plurality of chambers of each hydraulic motor. Provide hydraulic valves to turn on / off the supply, and turn each hydraulic valve on or off based on the pressure of the hydraulic oil that changes according to the load. Then, a means of changing one by one in a specific order is adopted.

  In the present invention, as a fifth solving means related to the hydraulic machine, in any one of the first to fourth solving means, a vane motor having two hydraulic motors and each hydraulic motor having three chambers. The method of being is adopted.

  Further, in the present invention, as a solving means related to the deck crane, a means is provided in which the hydraulic machine according to any one of the first to fifth solving means is provided, and the winch is driven by the hydraulic machine.

  According to the present invention, the number of chambers for supplying hydraulic oil is allowed to be different, not the same, between hydraulic motors as in the prior art. For example, when there are two hydraulic motors, hydraulic oil is supplied to two chambers of one hydraulic motor and hydraulic oil is supplied to one chamber of the other hydraulic motor, or one hydraulic motor is supplied. Since the hydraulic oil can be supplied to the three chambers of the motor and the hydraulic oil can be supplied to the two chambers of the other hydraulic motor, it is possible to realize speed switching that is finer than before.

1 is a hydraulic circuit diagram of a hydraulic machine A according to an embodiment of the present invention. It is a mimetic diagram showing a schematic structure of deck crane D concerning an embodiment of the present invention. In embodiment of this invention, it is a figure which shows the winding up / down rotation speed of the winding winch d7 according to a load (load). In embodiment of this invention, it is a schematic diagram (a)-(e) which shows the supply state of the hydraulic fluid to each chamber of the 1st hydraulic motor 5 and the 2nd hydraulic motor 6. FIG. It is a figure which shows operation | movement of the hydraulic machine A which concerns on embodiment of this invention, Comprising: The hydraulic circuit diagram (a) which shows the supply state of hydraulic fluid in case the load of the winding winch d7 is 7 tons, and the winding winch d7 It is a hydraulic-circuit figure (b) which shows the supply state of the hydraulic fluid in case a load is 14 tons. It is a figure which shows operation | movement of the hydraulic machine A which concerns on embodiment of this invention, Comprising: The hydraulic circuit diagram (a) which shows the supply state of hydraulic fluid in case the load of the winch d7 for winding is 21 tons, and the winch d7 for winding It is a hydraulic-circuit figure (b) which shows the supply state of the hydraulic fluid in case a load is 28 tons. It is a figure which shows operation | movement of the hydraulic machine A which concerns on embodiment of this invention, Comprising: It is a hydraulic circuit diagram which shows the supply state of hydraulic fluid in case the load of the winding winch d7 is 35 tons.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the hydraulic machine A according to the present embodiment includes an engine 1, a hydraulic pump 2, a first directional control valve 3, a second directional control valve 4, a first hydraulic motor 5, a second Hydraulic motor 6, first hydraulic valve 7, second hydraulic valve 8, third hydraulic valve 9, fourth hydraulic valve 10, first pressure switch 11, second pressure switch 12, first solenoid It is mainly composed of a valve 13 and a second solenoid valve 14. Such a hydraulic machine A is intended to drive a winding winch d7 of a deck crane D as shown in FIG.

  That is, the deck crane D is a cargo handling machine including the hydraulic machine A as a component, and is installed on the deck of a ship and used for loading / unloading loads as is well known. More specifically, as shown in FIG. 2, the deck crane D includes a crane post d1 provided on the deck, a rotating body d2 having a predetermined height rotatably provided on the crane post d1, and the rotation. A driver's cab d3 provided in the body d2, a boom d4 which protrudes obliquely forward and upward from the rotating body d2 and can be raised and lowered, a lifting winch d5 which defines an elevation angle of the boom d4, and suspended from the tip of the boom d4 At the same time, the hook at the tip is mainly composed of a wire rope d6 for baggage that engages with the baggage, and a winch d7 for winding / unwinding the wire rope for wire d6.

  The engine 1 of the hydraulic machine A is a power source that rotationally drives the hydraulic pump 2, and is, for example, a diesel engine. The hydraulic pump 2 discharges hydraulic oil having a constant pressure and a constant flow rate when driven by the engine 1, and is, for example, a positive displacement hydraulic pump. The discharge port of the hydraulic pump 2 is connected to the first directional control valve 3 and the second directional control valve 4 by piping as shown in FIG. That is, the hydraulic oil discharged from the discharge port of the hydraulic pump 2 is distributed and supplied to the first directional control valve 3 and the second directional control valve 4.

  The first directional control valve 3 is connected to a pair of supply / exhaust ports provided in the first hydraulic motor 5 by piping, and is supplied from the hydraulic pump 2 based on an operation instruction input from the cab d3. A hydraulic valve for supplying the hydraulic oil to one of the pair of supply and discharge ports. The second direction control valve 4 is connected to a pair of supply / exhaust ports provided in the second hydraulic motor 6 by piping, and the pair of supply / exhaust ports is based on an operation instruction input from the cab d3. It is a hydraulic valve that supplies hydraulic oil to one of the ports.

  The two first and second hydraulic motors 5 and 6 have their respective rotary shafts coupled to the rotary shaft of the winding winch d7, and rotate the winding winch d7. That is, the two first and second hydraulic motors 5 and 6 are axially coupled in parallel to the winding winch d7 to be driven and cooperate to drive the winding winch d7.

  The first hydraulic motor 5 is a vane type hydraulic motor that is rotated by hydraulic oil supplied from the hydraulic pump 2 via the first directional control valve 3, and includes three chambers (first to first hydraulic fluids). Third chambers 5a-5c) are provided. The rotation speed of the first hydraulic motor 5 varies depending on the number of oil supply chambers, that is, the volume (flow rate) of hydraulic oil received from the hydraulic pump 2 via the first directional control valve 3. The first hydraulic motor 5 rotates forward or backward depending on the flow direction of the hydraulic oil set by the first direction control valve 3.

  The second hydraulic motor 6 is a vane type hydraulic motor that is rotated by hydraulic fluid supplied from the hydraulic pump 2 via the second directional control valve 4, and includes three chambers (first to first hydraulic fluids). Third chambers 6a-6c) are provided. The rotation speed of the second hydraulic motor 6 varies depending on the number of oil supply chambers, that is, the volume (flow rate) of hydraulic oil received from the hydraulic pump 2 via the second directional control valve 4. The second hydraulic motor 6 rotates forward or backward depending on the flow direction of the hydraulic oil set by the second direction control valve 4.

  Here, the first directional control valve 3 described above is the above-described winding of the two left and right supply / exhaust ports provided in the first to third chambers 5a to 5c of the first hydraulic motor 5, respectively. When lifting the winch d7 (lifting the load), hydraulic oil is supplied to the left supply / discharge port, and when the winding winch d7 is used to unwind the load wire rope d6 (lowering the load), the right side Supply hydraulic fluid to the inlet / outlet. In addition, the second directional control valve 4 described above is loaded on the winding winch d7 among the two left and right supply / discharge ports provided in the first to third chambers 6a to 6c of the second hydraulic motor 6, respectively. Hydraulic oil is supplied to the left supply / discharge port when hoisting the wire rope d6 (lifting the load), and right side when unwinding the load wire rope d6 (lowering the load) to the winding winch d7. Supply hydraulic oil to the supply / discharge port.

  As shown in FIG. 1, the first hydraulic valve 7 is provided at the left supply / discharge port in the second chamber 5b of the first hydraulic motor 5, and the second chamber when the winding winch d7 is wound up. Turn ON / OFF the supply of hydraulic oil to 5b. The first hydraulic valve 7 includes hydraulic oil supplied from the first directional control valve 3 and the right side of the second and third chambers 5b and 5c of the first hydraulic motor 5 connected to each other by piping. Each supply / discharge port on the hydraulic oil discharge side during winding and each supply / discharge port on the right side of the second and third chambers 6b and 6c of the second hydraulic motor 6 (also the hydraulic oil discharge side during winding). The supply of hydraulic oil to the second chamber 5b is turned ON / OFF based on the balance with the hydraulic oil discharged to the second chamber 5b.

  Similarly, as shown in FIG. 1, the second hydraulic valve 8 is provided at the left supply / discharge port in the second chamber 6b of the second hydraulic motor 6, and the second chamber 8 when the winding winch d7 is wound up. Turn ON / OFF the supply of hydraulic oil to 6b. As shown in FIG. 1, the second hydraulic valve 8 is based on the balance between the hydraulic oil supplied from the second directional control valve 4 and the hydraulic oil supplied from the first solenoid valve 13. The supply of hydraulic oil to the second chamber 6b is turned ON / OFF.

  Similarly, as shown in FIG. 1, the third hydraulic valve 9 is provided at the left supply / discharge port in the third chamber 5c of the first hydraulic motor 5, and the third chamber 5c when the winding winch d7 is wound up. Turn ON / OFF the supply of hydraulic oil to The third hydraulic valve 9 is based on the balance between the hydraulic oil supplied to the second chamber 5b via the first hydraulic valve 7 and the hydraulic oil supplied from the first solenoid valve 13. The supply of hydraulic oil to the third chamber 5c is turned ON / OFF.

  Similarly, as shown in FIG. 1, the fourth hydraulic valve 10 is provided at the left supply / discharge port in the third chamber 6c of the second hydraulic motor 6, and the third chamber 6c when the winding winch d7 is wound up. Turn ON / OFF the supply of hydraulic oil to The fourth hydraulic valve 10 is based on the balance between the hydraulic oil supplied to the second chamber 6b via the second hydraulic valve 8 and the hydraulic oil supplied from the second solenoid valve 14. The supply of hydraulic oil to the third chamber 6c is turned ON / OFF.

  In other words, in this hydraulic machine A, the first and second hydraulic motors 5 and 6 are connected to the left and right outlets of the second and third chambers 5b, 5c, 6b and 6c except for the first chambers 5a and 6a. A hydraulic valve (any one of the first to fourth hydraulic valves 7 to 10) for turning on / off the supply of hydraulic oil is provided. Accordingly, when the winding winch d7 is wound up, the hydraulic oil discharged from the hydraulic pump 2 is supplied to the first directional control valve 3 in the first chambers 5a and 6a of the first and second hydraulic motors 5 and 6. Alternatively, it is directly supplied via the second directional control valve 4, but the hydraulic oil discharged from the hydraulic pump 2 is supplied to the second and third chambers 5b, 5c, 6b, and 6c from the first to the fourth. It is selectively supplied via any one of the hydraulic valves 7-10.

  In addition, the set pressure Xa (kPa) or the set pressure Xb (kPa) is set in advance in the first to fourth hydraulic valves 7 to 10 as a pressure condition for transition from the OFF state to the ON state. Although details of these set pressures Xa and Xb (kPa) will be described later, the first and second hydraulic valves 7 and 8 operate based on the set pressure Xa (kPa), and the third and fourth hydraulic valves 9. , 10 operate based on the set pressure Xb (kPa). The set pressure Xb (kPa) of the third and fourth hydraulic valves 9 and 10 is larger than the set pressure Xa of the first and second hydraulic valves 7 and 8.

  The first pressure switch 11 detects the hydraulic pressure of the hydraulic oil supplied to the second chamber 5b in the first hydraulic motor 5, and changes from the OFF state to the ON state when the hydraulic pressure exceeds the set pressure X1 (kPa). At the same time, an ON signal is output to the first solenoid valve 13. The second pressure switch 12 detects the hydraulic pressure of the hydraulic oil supplied to the third chamber 5c in the first hydraulic motor 5, and changes from the OFF state to the ON state when the hydraulic pressure exceeds the set pressure X2 (kPa). At the same time, the ON signal is output to the second solenoid valve 14. Here, the set pressure X2 (kPa) which is a condition for the second solenoid valve 14 to transition from the OFF state to the ON state is the set pressure which is a condition for the first solenoid valve 13 to transition from the OFF state to the ON state. A value larger than X1 (kPa) is set.

  The first solenoid valve 13 is a kind of solenoid valve that operates by moving a plunger by a solenoid. When an ON signal is input from the first pressure switch 11, the first solenoid valve 13 is switched from a conductive state (ON state) to a non-conductive state (OFF). State). That is, when the ON signal is input from the first pressure switch 11, the first solenoid valve 13 is supplied to the second hydraulic valve 8 and the third hydraulic valve 9 of the hydraulic oil supplied from the hydraulic pump 2. Stop supplying.

  Similarly to the first solenoid valve 13, the second solenoid valve 14 is a valve that is opened and closed by a solenoid. When an ON signal is input from the second pressure switch 12, the second solenoid valve 14 is switched from a conductive state (ON state) to a non-conductive state ( (OFF state). That is, when the ON signal is input from the second pressure switch 12, the second solenoid valve 14 stops supplying the hydraulic oil supplied from the hydraulic pump 2 to the fourth hydraulic valve 10.

Next, the operation of the hydraulic machine A configured as described above will be described in detail with reference to FIGS.
5 to 7, the pipes indicated by bold lines are pipes through which hydraulic oil flows, the pipes indicated by dotted lines are hydraulic oil return pipes, and the pipes indicated by alternate long and short dashed lines Indicates that the flow of hydraulic oil is blocked.

  First, in this hydraulic machine A, the load range (load range) applied to the winding winch d7 when lifting the load is divided into a plurality of small areas, and the first and second hydraulic motors 5 are divided according to the small areas. , 6 (the winding speed of the winding winch d7) is switched. For example, as shown in FIG. 3, the load range (0 to 100%) that can be pulled up by the winding winch d7 includes five small regions E1 to E5 (0 ≦ E1 ≦ 20%, 20% <E2 ≦ 40%, 40%). <E3 ≦ 60%, 60% <E4 ≦ 80%, 80% <E5 ≦ 100%). When the load of the winding winch d7 belongs to the first (minimum) small area E1, the first chamber 5a and the second hydraulic pressure of the first hydraulic motor 5 as shown in FIG. 4 (a). The hydraulic oil is supplied only to the first chamber 6a of the motor 6.

  In the hydraulic machine A, when the load of the winch belongs to the second small region E2, the first chamber 5a and the second chamber of the first hydraulic motor 5 as shown in FIG. 4B. The hydraulic fluid is supplied only to the first chamber 6a of the second hydraulic motor 6 and 5b. Further, in this hydraulic machine A, when the load of the winding winch d7 belongs to the third small region E3, the first chamber 5a and the first chamber 5a of the first hydraulic motor 5 and the second one as shown in FIG. The hydraulic oil is supplied only to the second chamber 5b and the first chamber 6a and the second chamber 6b of the second hydraulic motor 6.

  Further, in this hydraulic machine A, when the load of the winding winch d7 belongs to the fourth small region E4, the first chamber 5a of the first hydraulic motor 5 and the second one as shown in FIG. The hydraulic oil is supplied only to the second chamber 5b and the third chamber 5c and the first chamber 6a and the second chamber 6b of the second hydraulic motor 6. Further, in the hydraulic machine A, when the load of the winding winch d7 belongs to the fifth (maximum) small region E5, as shown in FIG. 4 (e), the first hydraulic motor 5 and the second hydraulic pressure The hydraulic oil is supplied to all the chambers (first to third chambers 5a to 5c, 6a to 6c) of the motor 6.

  That is, the hydraulic machine A sets the number of oil supply chambers in the first and second hydraulic motors 5 and 6 when lifting the load (winding the winding winch d7). The number of oil supply chambers varies depending on whether the load of the winding winch d7 belongs to any of the small areas E1 to E5.

  In the case of a load belonging to the second to fifth (maximum) small regions E2 to E5 other than the first (minimum) small region E1, for example, the fifth (maximum) small region E5, the first hydraulic pressure First, the number of oil supply chambers of the motor 5 increases by one, then the number of oil supply chambers of the second hydraulic motor 6 increases by one, and then the number of oil supply chambers of the first hydraulic motor 5 increases by one. Finally, the number of oil supply chambers of the second hydraulic motor 6 is increased by one, so that the maximum number of the first and second hydraulic motors 5 and 6 becomes 3 chambers (6 chambers in total).

  That is, in this hydraulic machine A, when the load (load) of the winding winch d7 when lifting the load is relatively large, the number of oil supply chambers of the first and second hydraulic motors 5 and 6 is the first. By alternately increasing one by one in the order of the hydraulic motor 5 to the second hydraulic motor 6, winding up in five stages (100%, a%, b%, c%, d%) as shown in FIG. Realize rotational speed.

  Next, the operation of the hydraulic machine A for realizing such five-stage hoisting rotational speed will be described in detail with reference to FIGS.

  In the following, the operation state of the hydraulic machine A when the load of the winding winch d7 is 7 tons, 14 tons, 21 tons, 28 tons and 35 tons will be described. 14 tons is a load belonging to the second small area E2, 21 tons is a load belonging to the third small area E3, and 28 tons is a load belonging to the fourth small area E2. A load belonging to E4 and 35 tons is a load belonging to the fifth (maximum) small region E5.

  First, the case where the load of the winding winch d7 is 7 tons will be described. In this case, as shown in FIG. 5A, all of the first to fourth hydraulic valves 7 to 10 are in the OFF state, so the first chambers of the first and second hydraulic motors 5 and 6 are used. Hydraulic oil is supplied only to 5a and 6a. That is, in this case, since the load (load) is relatively light, the hydraulic pressure of the hydraulic oil supplied from the first directional control valve 3 to the first hydraulic valve 7 causes the first hydraulic valve 7 to change state. Set pressure Xa (kPa) is not reached, so the first hydraulic valve 7 is OFF. The set pressure Xa (kPa) is smaller than the set pressure X1 (kPa) of the first pressure switch 11 described above.

  As a result, the hydraulic oil pressure detected by the first and second pressure switches 11 and 12 does not increase to the extent that the first and second pressure switches 11 and 12 are shifted from the OFF state to the ON state. The first and second solenoid valves 13 and 14 are in the ON state. Accordingly, the second and third hydraulic valves 8 and 9 are supplied with hydraulic fluid from the first solenoid valve 13, and the fourth hydraulic valve 10 is supplied with hydraulic fluid from the second solenoid valve 14. Therefore, the second to fourth hydraulic valves 8 to 10 are also in the OFF state, like the first hydraulic valve 7 described above.

  Next, the case where the load of the winding winch d7 is 14 tons will be described. In this case, as shown in FIG. 5B, of the first to fourth hydraulic valves 7 to 10, only the first hydraulic valve 7 is turned on, and the first and second hydraulic motors 5 and 6 are turned on. In addition to the first chambers 5a and 6a, the hydraulic oil is supplied to the second chamber 5b of the first hydraulic motor 5. That is, in this case, although the load (load) is still relatively light, the hydraulic pressure of the hydraulic oil supplied from the first directional control valve 3 to the first hydraulic valve 7 exceeds the set pressure Xa (kPa). The first hydraulic valve 7 transitions from the OFF state to the ON state. On the other hand, since the hydraulic pressure of the hydraulic oil is not so high that the first and second pressure switches 11 and 12 transition to the ON state, the first and second solenoid valves 13 and 14 are in the ON state. Unlike the first hydraulic valve 7, the second to fourth hydraulic valves 8 to 10 maintain the OFF state.

  Next, the case where the load of the winding winch d7 is 21 tons will be described. In this case, as shown in FIG. 6A, among the first to fourth hydraulic valves 7 to 10, the first and second hydraulic valves 7 and 8 are turned on, and the first and second hydraulic valves are turned on. The hydraulic oil is supplied to the first chambers 5a, 6a and the second chambers 5b, 6b of the motors 5, 6. That is, in this case, the hydraulic pressure of the hydraulic oil (the hydraulic oil supplied to the second chamber 5b of the first hydraulic motor 5) detected by the first pressure switch 11 is set by the first pressure switch 11. Since the pressure exceeds X1 (kPa), the first pressure switch 11 transitions from the OFF state to the ON state and outputs an ON signal to the first solenoid valve 13.

  As a result, the first solenoid valve 13 transitions from the ON state to the OFF state, and stops supplying hydraulic oil to the second and third hydraulic valves 8 and 9. Here, the hydraulic pressure of the hydraulic oil supplied to the second hydraulic valve 8 exceeds the set pressure Xa (kPa), while the hydraulic oil supplied to the third hydraulic valve 9 via the first hydraulic valve 7 The hydraulic pressure does not exceed the set pressure Xb (kPa) larger than the set pressure Xa (kPa).

  Accordingly, when the supply of hydraulic oil from the first solenoid valve 13 is stopped, only the second hydraulic valve 8 changes to the ON state, and the third hydraulic valve 9 maintains the OFF state. The set pressure Xb is larger than the set pressure X1 (kPa) of the first pressure switch 11 and smaller than the set pressure X2 (kPa) of the second pressure switch 11.

  Next, the case where the load of the winding winch d7 is 28 tons will be described. In this case, as shown in FIG. 6 (b), among the first to fourth hydraulic valves 7 to 10, the third hydraulic valve 9 is in an ON state in addition to the first and second hydraulic valves 7 and 8. Thus, hydraulic oil is supplied to the first and second chambers 5 a, 5 b, 6 a, 6 b of the first and second hydraulic motors 5, 6 and the third chamber 5 c of the first hydraulic motor 5. That is, in this case, since the hydraulic pressure of the hydraulic oil supplied to the third hydraulic valve 9 via the first hydraulic valve 7 exceeds the set pressure Xb (kPa), the third hydraulic valve 9 is in the OFF state. Transition from ON to ON state. However, in this case, since the hydraulic pressure of the hydraulic oil is not so high that the second pressure switch 12 changes from the OFF state to the ON state, the second solenoid valve 14 is in the ON state, and thus the fourth hydraulic pressure The valve 10 maintains the OFF state.

  Next, the case where the load of the winding winch d7 is 35 tons will be described. In this case, as shown in FIG. 7, all of the first to fourth hydraulic valves 7 to 10 are turned on, and all the chambers (first to third chambers) of the first and second hydraulic motors 5 and 6 are turned on. 5a-5c, 6a-6c) is supplied with hydraulic oil. That is, in this case, the hydraulic pressure of the hydraulic oil (the hydraulic oil supplied to the third chamber 5c of the first hydraulic motor 5) detected by the second pressure switch 12 is set by the second pressure switch 12. Since the pressure X2 (kPa) is exceeded, the second pressure switch 12 transitions from the OFF state to the ON state and outputs an ON signal to the second solenoid valve 14.

  As a result, the second solenoid valve 14 transitions from the ON state to the OFF state and stops the supply of hydraulic oil to the fourth hydraulic valve 10. When the supply of hydraulic fluid from the second solenoid valve 14 is stopped, the fourth hydraulic valve 10 transitions from the OFF state to the ON state, and the fourth hydraulic valve 10 enters the ON state. As a result, the hydraulic oil is also supplied to the third chamber 6 c of the second hydraulic motor 6 via the fourth hydraulic valve 10.

  According to the present embodiment, since the number of oil supply chambers is allowed to be different between the first and second hydraulic motors 5 and 6, the number of oil supply chambers is changed to the first and second hydraulic motors 5. , 6 can be alternately increased one by one so that the hoisting rotational speed of the winding winch d7 can be switched to five stages, which is higher than the conventional three stages. That is, in the conventional deck crane, since the number of oil supply chambers of the two hydraulic motors is always the same, the number of oil supply chambers of the two hydraulic motors changes from 1 → 2 → 3 at the same time. However, according to the present embodiment, as described above, the level is switched to five levels. Therefore, according to this embodiment, since the switching of the hoisting rotational speed can be realized more finely than in the past, cargo handling work can be performed more efficiently than in the past.

  In addition, according to the present embodiment, the number of oil supply chambers is alternately increased one by one for the first and second hydraulic motors 5 and 6, so that the oil supply between the first and second hydraulic motors 5 and 6 is performed. The difference in the number of chambers is at most one. Therefore, since the load imbalance of the first and second hydraulic motors 5 and 6 can be minimized, the difference in the number of chambers of the first and second hydraulic motors 5 and 6 is set to two or more. The durability of the first and second hydraulic motors 5 and 6 can be made more equal than in the case.

  Furthermore, according to the present embodiment, the number of oil supply chambers is set by the first to fourth hydraulic valves 7 to 10, the first and second pressure switches 11 and 12, and the first and second solenoid valves 13 and 14. It is realized that the first and second hydraulic motors 5 and 6 are alternately increased one by one. That is, since the number of oil supply chambers is alternately increased by one for each of the first and second hydraulic motors 5 and 6 with a simple hydraulic circuit configuration, the reliability of the hydraulic machine A is high.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, For example, the following modifications can be considered.
(1) In each of the above embodiments, the winding winch d7 of the deck crane D is driven, but the present invention is not limited to this. The present invention can be applied to various driving objects other than the deck crane D, and for example, the turning mechanism of the deck crane D may be the driving object.
(2) In each of the above embodiments, two hydraulic motors (first and second hydraulic motors 5 and 6) are provided, but the present invention is not limited to this. The present invention can also be applied to a case where three or more hydraulic motors are provided.
(3) In the above embodiments, the first and second hydraulic motors 5 and 6 each include three chambers, but the present invention is not limited to this. A hydraulic motor having two chambers or four or more chambers may be employed.

(4) Furthermore, in the above embodiment, when the load of the winding winch d7 belongs to the first (minimum) small region E1, the first chambers 5a, 6a of the first and second hydraulic motors 5, 6 are used. Hydraulic oil is supplied to That is, in the above embodiment, when the load of the winding winch d7 belongs to the first small region E1, the number of oil supply chambers is set to “2”, but the present invention is not limited to this, and the winding winch d7 When the load belongs to the first small region E1, the number of oil supply chambers is set to “1”, that is, the hydraulic oil is supplied only to the first chamber 5a of the first hydraulic motor 5, whereby the hoisting rotational speed is increased. May be switched to 6 levels.

(5) In each of the above embodiments, when the number of oil supply chambers is increased, the first hydraulic motor 5 is incremented prior to the second hydraulic motor 6, but the present invention is limited to this. Not. That is, the order in increasing the number of oil supply chambers is not limited to the fixed order in which the first hydraulic motor 5 is followed by the second hydraulic motor 6. For example, the number of oil supply chambers is increased in the order as in each of the above embodiments in an operation period of the deck crane D, but the order may be changed in the next operation period.

DESCRIPTION OF SYMBOLS A ... Hydraulic machine, 1 ... Engine, 2 ... Hydraulic pump, 3 ... 1st direction control valve, 4 ... 2nd direction control valve, 5 ... 1st hydraulic motor, 6 ... 2nd hydraulic motor, 7 ... 1st hydraulic valve, 8 ... 2nd hydraulic valve, 9 ... 3rd hydraulic valve, 10 ... 4th hydraulic valve, 11 ... 1st pressure switch, 12 ... 2nd pressure switch, 13 ... 1st 14 solenoid valve, 14 second solenoid valve, 5 a, 6 a first chamber, 5 b, 6 b second chamber, 5 c, 6 c third chamber, D deck crane, d 1 crane post, d 2 ... rotary body, d3 ... cab, d4 ... boom, d5 ... lifting winch, d6 ... wire rope for luggage, d7 ... winding winch

Claims (6)

A hydraulic machine that includes a plurality of chambers and that is speed-controlled by switching the number of chambers that supply hydraulic oil according to a load with respect to a plurality of hydraulic motors that are axially coupled to a drive target in parallel.
A hydraulic machine characterized in that the number of chambers for supplying hydraulic oil is allowed to vary among the hydraulic motors.   2. The hydraulic machine according to claim 1, wherein the number of chambers for supplying hydraulic oil is changed one by one in a specific order according to a load for a plurality of hydraulic motors.   Dividing the load fluctuation range into a plurality of small areas, and in each of the small areas where the load is minimum, hydraulic oil is supplied to one chamber for each hydraulic motor, and the number of chambers supplying hydraulic oil is specified according to the load. The hydraulic machine according to claim 1, wherein the hydraulic machine is changed one by one in order.   A hydraulic valve that turns ON / OFF the supply of hydraulic oil is provided in each of the plurality of chambers of each hydraulic motor except for at least one, and each hydraulic valve is turned ON based on the pressure of the hydraulic oil that changes according to the load. The hydraulic machine according to any one of claims 1 to 3, wherein the number of chambers for supplying hydraulic oil is changed one by one in a specific order according to a load by setting the state or the OFF state. .   The hydraulic machine according to any one of claims 1 to 4, wherein two hydraulic motors are provided, and each hydraulic motor is a vane motor having three chambers.   A deck crane comprising the hydraulic machine according to any one of claims 1 to 5, wherein a winch is driven by the hydraulic machine.

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