JP6509569B2 - Fluid pressure control device - Google Patents

Description

  The present invention relates to a fluid pressure control device applied to, for example, automobiles, construction machines, transport vehicles, industrial vehicles, hydraulic devices of industrial machines, and the like.

  In the conventional fluid pressure control device, a pump driven by a drive mechanism, a pressure increasing device for increasing the pressure of the working fluid discharged from the pump, and a fluid pressure increased by the pressure increasing device are accumulated. BACKGROUND A fluid pressure control device is known that includes a pressure storage device that supplies pressure to a pressure-supplied circuit (see, for example, Patent Document 1).

JP 2011-185417 A (FIG. 1)

  More specifically, in the conventional fluid pressure control device, as shown in, for example, FIGS. 7A and 7B, the hydraulic fluid supplied by the hydraulic pump 102 having the drive mechanism 101 as a drive source is hydraulically supplied. It is supplied to the circuit 104. A portion of the hydraulic oil is branched into the branch pipe 105, and is alternately supplied to the large diameter oil chamber 172 and the middle oil chamber 171 of the pressure booster 170 by switching the flow path of the switching valve 106. The piston 175 reciprocates inside the case 173 of the pressure device 170. The reciprocating motion of the piston 175 causes the hydraulic oil in the tank 110 to be sucked into the small diameter oil chamber 174 of the pressure booster 170 via the suction pipe 131 using a negative pressure, and the pressure accumulator 108 with pressure higher than the pump pressure. The pressure is discharged and accumulated.

  In such a conventional fluid pressure control device, when the working oil is accumulated in the accumulator 108 by the reciprocation of the piston 175 from the initial state where the hydraulic oil is not accumulated in the accumulator 108, the piston 175 is used. Since only the hydraulic fluid of the volume (volume) of the small diameter oil chamber 174 is discharged in one cycle of the cycle, the piston 175 is repeatedly used until the pressure storage device 108 reaches the preload equivalent to the discharge pressure of the hydraulic pump 102. It was necessary to make it go back and forth, and it took a considerable amount of time.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a fluid pressure control device capable of causing a pressure accumulator to reach a preload early.

In order to solve the above-mentioned subject, the fluid pressure control device of the present invention,
A fluid comprising at least a pump for discharging a working fluid, a pressure increasing device capable of increasing the pressure by discharging the working fluid discharged from the pump, and a pressure accumulator for storing pressure the working fluid discharged from the pressure increasing device. Pressure control device,
The pressure increasing device has a drive chamber for introducing the working fluid discharged by the pump, and a communication chamber in communication with the pressure storage device and capable of discharging the working fluid by increasing the discharge pressure of the pump.
It is characterized in that a switching valve capable of switching the flow path of the working fluid to the drive chamber or the communication chamber is provided between the pump and the pressure increasing device.
According to this feature, the working fluid discharged from the pump is supplied to the communication chamber of the pressure intensifier, the pressure in the initial state of the communication chamber reaches the preload equivalent to the discharge pressure of the pump early, and the pressure is further increased. Since the pressure can be increased by the device and supplied to the pressure storage device, the pressure accumulation time for supplying the working fluid to the pressure storage device as a whole can be significantly shortened. In addition, when the pressure discharged from the pump is larger than the preload pressure of the pressure accumulator, working fluid is supplied to the pressure accumulator via the communication chamber using the discharge pressure of the pump, and pressure is further increased by the pressure booster. Since the pressure can be supplied to the pressure accumulator, the pressure accumulation time can be further shortened.

The fluid pressure control device of the present invention is
A check valve is provided between the pressure intensifier and the pressure accumulator, which allows the flow of working fluid from the pressure intensifier to the pressure accumulator.
According to this feature, since the working fluid pressurized by the pressure intensifier does not stay in the pressure intensifier, the pressure intensifying function can be exhibited without affecting the pressure intensifying step.

The fluid pressure control device of the present invention is
The pressure intensifying device further includes a piston that moves at least the volumes of the drive chamber and the communication chamber by pressure of the working fluid.
According to this feature, since the piston can be moved toward the drive chamber in advance by using the working fluid flowing into the communication chamber at the discharge pressure of the pump, the piston moved to the drive chamber can be used as the working fluid. A stroke allowance moving to the communication chamber can be obtained while pressure is increased.

The fluid pressure control device of the present invention is
The pressure increasing device may further include biasing means for biasing the piston toward the drive chamber.
According to this feature, the biasing means biases the piston toward the drive chamber, so that the piston moved toward the communication chamber can be moved to the drive chamber early and reliably.

The fluid pressure control device of the present invention is
The pressure increasing device further includes an open chamber that releases pressure to the outside regardless of the movement of the piston, and the biasing unit is provided in the open chamber.
According to this feature, by providing the biasing means in the open chamber in which the pressure is always released, the biasing means can apply the biasing force to the piston without being affected by the pressure of the working fluid.

It is a hydraulic circuit diagram of the fluid pressure control apparatus in Example 1, (a) shows the de-energized state of an electromagnetic switching valve, (b) is a figure which similarly shows an excited state. It is a hydraulic circuit diagram of the fluid pressure control apparatus in Example 2, (a) shows the de-energized state of an electromagnetic switching valve, (b) is a figure which similarly shows an excited state. FIG. 7 is a hydraulic circuit diagram of a fluid pressure control device in a modification of the first embodiment. FIG. 13 is a hydraulic circuit diagram of a fluid pressure control device in a modification of the second embodiment. FIG. 13 is a hydraulic circuit diagram of a fluid pressure control device in another modification of the second embodiment. It is the figure which compared the time which pressure-accumulates to a pressure accumulation apparatus by this invention and prior art. It is a hydraulic circuit diagram of the fluid pressure control apparatus in a prior art, (a) shows the de-energized state of an electromagnetic switching valve, (b) is a figure which similarly shows an excited state.

  A mode for carrying out a fluid pressure control device according to the present invention will be described below based on an example.

  The fluid pressure control device according to the first embodiment will be described with reference to FIGS. 1 (a) and 1 (b). First, FIG. 1 is a hydraulic circuit diagram of a fluid pressure control device to which the present invention is applied.

  The fluid pressure control device according to the first embodiment includes a hydraulic pump 2 that sucks and discharges hydraulic oil as a working fluid from a tank 10, a drive mechanism 1 that transmits rotational driving force to the hydraulic pump 2, and the hydraulic pump 2. It mainly includes a hydraulic pressure supplied circuit 4 connected via a check valve 12 and a main pipe 3 and supplied with hydraulic oil at the discharge pressure of the hydraulic pump 2. The hydraulic pressure supplied circuit 4 is a circuit for driving, for example, an actuator of an automobile, an industrial machine or the like described later.

  Further, the fluid pressure control device is connected to the electromagnetic switching valve 6 connected to the branch pipe 5 branched from the main pipe 3, and to the electromagnetic switching valve 6 via the switching pipes 13 and 30. The pressure increasing device 7 increases pressure and discharges, and the accumulator 8 as a pressure accumulating device connected between the pressure increasing device 7 and the hydraulic pressure supplied circuit 4 via the check valve 14 and the high pressure pipe 15 and the like. Other components of the fluid pressure control device will be described later.

  The fluid pressure control device of this embodiment is applied as a hydraulic device of, for example, an automobile, a construction machine, a transport vehicle, an industrial machine, etc., for example, a brake, a steering, a transmission, etc. of an automobile or a truck, a hydraulic shovel, a forklift It is a device applied to each actuator such as a crane, a refuse collection vehicle or a press machine.

  Next, the pressure increasing device 7 has a case 73 having a substantially T-shaped housing space in a plan view, and a shape fitted in the housing space of the case 73, and has a relatively large diameter large diameter portion and a small diameter. And a piston 75 having a small diameter portion. Further, the piston 75 is slidably disposed in the inside of the case 73 via a seal member (not shown) on the inner surface of the case 73. That is, the inside of the case 73 is divided into three oil chambers consisting of a relatively large diameter oil chamber 72, a small diameter oil chamber 74, and an oil chamber 71 having a diameter obtained by subtracting the small diameter portion from the large diameter portion. The volume (volume) of the

  The oil chamber 74 is connected to the accumulator 8 through the check valve 14 and the high pressure pipe 15 described above, and separately from this, is communicated with the electromagnetic switching valve 6 described later through the check valve 17 and the switching pipe 30. It is connected to the. The non-return valve 14 connected to the oil chamber 74 allows forward flow of hydraulic fluid from the oil chamber 74 to the accumulator 8 and restricts reverse flow of hydraulic fluid from the accumulator 8 to the oil chamber 74 . Further, another check valve 17 connected to the oil chamber 74 allows forward flow of the hydraulic oil from the electromagnetic switching valve 6 to the oil chamber 74, and the hydraulic fluid of the hydraulic chamber 74 to the electromagnetic switching valve 6. Regulate the flow in the reverse direction.

  Further, the oil chamber 71 is connected to the inside of the tank 10 via the pipe line 31 and pressure-released to the outside regardless of the movement of the piston 75, and the volume (volume) of the oil chamber 71 accompanying the reciprocation of the piston 75 The hydraulic oil is sucked from the tank 10 into the oil chamber 71 or discharged from the oil chamber 71 into the tank 10.

  The oil chamber 72 of the first embodiment constitutes the drive chamber of the present invention, the oil chamber 74 constitutes the communication chamber of the present invention, and the oil chamber 71 constitutes the open chamber of the present invention.

  Further, the electromagnetic switching valve 6 is disposed so as to be able to switch the flow path of the hydraulic oil in the demagnetized state or the excited state. More specifically, in the demagnetized state shown in FIG. 1A, the electromagnetic switching valve 6 establishes communication between the branch pipe 5 and the switching pipe 30 connected to the oil chamber 74, and switches the switching pipe 13 connected to the oil chamber 72. And the end communicate with the discharge pipe 16 opened to the tank 10. Further, the electromagnetic switching valve 6 communicates the branch pipe 5 with the switching pipe 13 connected to the oil chamber 72 in the excited state shown in FIG. 1B, and discharges the switching pipe 30 connected to the oil chamber 74. It communicates with the tube 16.

  The pipeline from the hydraulic pump 2 described above to the accumulator 8 via the branch pipe 5, the electromagnetic switching valve 6, the switching pipe 30, the check valve 17, the oil chamber 74, the check valve 14 and the high pressure pipe 15 is common Thus, the direct pipe line and the pressure intensifying pipe line of the present invention are configured.

  Next, although not particularly shown, the accumulator 8 is composed of a cylindrical body portion communicating with the high pressure pipe 15 and a film body made of rubber or the like disposed in the cylindrical body portion. A predetermined amount of pressure-accumulated gas is enclosed, and as described later, when hydraulic fluid flows into the cylinder body, the membrane contracts in accordance with the pressure, whereby the high-pressure fluid can be stored.

  Further, the fluid pressure control device includes a relief valve 20 capable of discharging the hydraulic oil to the tank 10 through the discharge pipe 21 branched from the main pipe 3 and a discharge pipe 23 branched similarly from the high pressure pipe 15 in addition to the components described above. The high pressure pipe 19 connecting the accumulator 8 and the hydraulic pressure supplied circuit 4 is provided with a relief valve 24 capable of discharging the hydraulic oil to the tank 10 and the electromagnetic switching valve 9 capable of opening and closing the pipe. A stop valve 18 is interposed.

  Next, the flow of the hydraulic oil in the fluid pressure control device of the first embodiment will be described.

  First, as shown in FIG. 1A, in the initial state in which the accumulator 8 is not preloaded, the control valve (not shown) demagnetizes the electromagnetic switching valve 6. A portion of the hydraulic oil discharged from the hydraulic pump 2 in this state is supplied to the hydraulic pressure supplied circuit 4 through the main pipe 3 by the discharge pressure of the hydraulic pump 2, and the remaining portion is the branch pipe 5, electromagnetic switching It flows into the oil chamber 74 through the valve 6.

  Furthermore, the hydraulic oil that has flowed into the oil chamber 74 flows into the cylinder body of the accumulator 8 at a flow rate with the hydraulic pump 2 as a drive source, and the membrane contracts, and the hydraulic pump is filled with the hydraulic pump A preloaded condition corresponding to a discharge pressure of 2 is reached. That is, in this initial state, the hydraulic fluid flows from the hydraulic pump 2 directly to the accumulator 8 through the pipeline. In this initial state, the switching valve 9 is closed, and the supply of hydraulic oil to the hydraulic pressure supplied circuit 4 through the high pressure pipe 19 is shut off.

  Subsequently, in a state after the accumulator 8 is preloaded, the electromagnetic switching valve 6 repeats the demagnetization state of FIG. 1A and the excitation state of FIG. 1B by the control unit. More specifically, in the excited state of the solenoid control valve 6, the hydraulic fluid discharged from the hydraulic pump 2 flows into the oil chamber 72 via the branch pipe 5 and the solenoid switch valve 6. The hydraulic fluid having flowed into the oil chamber 72 presses the piston 75 toward the left in the figure, that is, the oil chamber 74 by the discharge pressure of the hydraulic pump 2.

  The pressure of the hydraulic oil in the oil chamber 74 is increased by the pressure of the discharge pressure of the hydraulic pump 2 and discharged according to so-called Pascal's theorem, and the cylinder of the accumulator 8 is discharged via the check valve 14 and the high pressure pipe 15. The film body further contracts by flowing into the portion, and the hydraulic oil which has reached a higher pressure than the above-described pre-load is accumulated in the accumulator 8 and the high pressure pipe 15. That is, in this post-pressure state, the hydraulic oil flows from the hydraulic pump 2 into the accumulator 8 through the pressure intensifying line.

  Thus, from the hydraulic pump 2, the direct pipe line and the intensifying pipe line described above are connected to the branch pipe 5, the electromagnetic switching valve 6, the switching pipe 30, the check valve 17, the oil chamber 74, the check valve 14 and the high pressure pipe 15. Since the pipe members of the direct pipe line and the pressure intensifying pipe line can be made common by directly using the common pipe line leading to the accumulator 8, the number of parts can be reduced without making the pipe line complicated.

  Further, since the piston 75 can be moved in advance toward the end of contraction on the side of the oil chamber 72 by using the hydraulic oil flowing into the oil chamber 74 as the communication chamber by the discharge pressure of the hydraulic pump 2, the oil It is possible to obtain a stroke allowance in which the piston 75 moved to the chamber 72 moves to the extension end on the oil chamber 74 side while pressurizing the hydraulic oil.

  Further, since hydraulic fluid can be supplied to both the oil chamber 72 and the oil chamber 74 by the discharge pressure of the hydraulic pump 2, not only switching of the reciprocating motion of the piston 75 can be performed instantaneously, but one oil chamber 71 It can be an open chamber that releases pressure to the outside regardless of the movement of the piston. On the other hand, in the prior art shown in FIG. 7, since the hydraulic oil is supplied from the tank 110 to the pressure-increasing chamber 174 using negative pressure through the suction pipe 131, the extension of the suction pipe 131 is limited. Become.

  Further, the check valve 14 is interposed between the oil chamber 74 and the accumulator 8 so that the hydraulic oil introduced into the accumulator 8 does not backflow into the oil chamber 74 and the pressure is increased by the pressure increasing device 7. Since the hydraulic oil does not stay in the pressure increasing device 7, the pressure increasing function can be performed without affecting the pressure increasing step, and the high pressure stored in the accumulator 8 can be maintained. In addition, since the check valve 14 is provided independently of the pressure increasing device 7, the pressure increasing device 7 does not affect the pressure increasing device 7 even if the accumulator 8 maintains a high pressure. The pressure boosting function can be exhibited regardless of the pressure condition of 8.

  Further, by interposing the check valve 17 between the electromagnetic switching valve 6 and the oil chamber 74, the hydraulic oil introduced into the oil chamber 74 does not backflow to the electromagnetic switching valve 6, and this hydraulic oil can be reliably Can be introduced into the accumulator 8.

  Next, when high pressure hydraulic oil is requested to the hydraulic pressure supplied circuit 4 under predetermined conditions, the control unit opens the switching valve 9 and the high pressure hydraulic oil in the high pressure pipe 15 and the accumulator 8 Flows into the hydraulic pressure supplied circuit 4.

  Next, as shown in FIG. 6, the pressure accumulation time to the accumulator 8 will be described in comparison with the prior art. In FIG. 6, the horizontal axis T indicates the pressure accumulation time, and the vertical axis P indicates the pressure in the accumulator 8.

  According to the fluid pressure control device of the present invention, discharge of the hydraulic pump 2 is performed from the initial state (T = 0, P = 0) in which the pressure of the hydraulic fluid is not applied to the accumulator 8 as shown by the solid line in FIG. In a very short time (T1) using the flow rate, pressure is accumulated in the accumulator 8 up to a preload (Ps) corresponding to the discharge pressure of the hydraulic pump 2. Subsequently, the piston 75 of the pressure increasing device 7 is reciprocated by the electromagnetic switching valve 6, and a predetermined amount of hydraulic oil flows into the accumulator 8 per stroke, whereby the internal pressure gradually increases, and finally the conventional device The accumulator 8 is in a constant high pressure state (Ph) with a short arrival time (T2).

  On the other hand, according to the conventional fluid pressure control device (see FIG. 7), as shown by the dotted line in FIG. 6, the initial state (T = 0, P = 0) in which the pressure of hydraulic fluid is not applied to the accumulator 8 Therefore, in order to increase the internal pressure, it is necessary to reciprocate the piston 75 of the pressure increasing device 7 a number of times, so the fluid pressure control of the present invention is performed until the accumulator 8 finally reaches a high pressure state (Ph). It requires a very long arrival time (T3) compared to the arrival time (T2) of the device (T3> T2).

  Thus, the hydraulic oil discharged from the hydraulic pump 2 is supplied to the oil chamber 74 as the communication chamber of the pressure increasing device 7, and the pressure in the initial state of the oil chamber 74 is preloaded equivalent to the discharge pressure of the hydraulic pump 2. Since the pressure can be reached early and pressure can be increased by the pressure increasing device 7 and supplied to the accumulator 8, the pressure accumulation time for supplying the hydraulic oil to the accumulator 8 as a whole can be shortened significantly. In addition, when the pressure discharged from the hydraulic pump 2 is larger than the preload pressure of the accumulator 8, the hydraulic oil is supplied to the accumulator 8 via the oil chamber 74 using the discharge pressure of the hydraulic pump 2, and the hydraulic oil Can be boosted by the pressure booster 7 and supplied to the accumulator 8, so that the pressure accumulation time for supplying the hydraulic oil to the accumulator 8 as a whole can be further shortened.

  Next, a fluid pressure control device according to a second embodiment will be described with reference to FIGS. 2 (a) and 2 (b). The same configuration as that of the first embodiment will not be described.

  The inside of the case 73 of the pressure increasing device 7 of the second embodiment comprises an oil chamber 72 having a relatively large diameter, an oil chamber 74 'having a small diameter, and an oil chamber 71' having a diameter obtained by subtracting the small diameter portion from the large diameter portion. The volume (volume) of these is divided into three oil chambers in a variable manner.

  The oil chamber 71 'of the pressure increasing device 7 of the second embodiment is connected to the accumulator 8 via the check valve 14 and the high pressure pipe 15, and separately, will be described later via the check valve 17 and the switching pipe 32. It is connected in communication with the electromagnetic switching valve 6. The non-return valve 14 connected to the oil chamber 71 'allows the forward flow of hydraulic fluid from the oil chamber 71' to the accumulator 8 and the reverse flow of hydraulic fluid from the accumulator 8 to the oil chamber 71 ' Regulate. Furthermore, another check valve 17 connected to the oil chamber 71 'allows forward flow of hydraulic fluid from the solenoid valve 6 to the oil chamber 71', and from the oil chamber 71 'to the solenoid valve 6. Regulate the reverse flow of hydraulic fluid.

  Further, the oil chamber 74 'is connected to the inside of the tank 10 via the conduit 33, and the pressure is released to the outside regardless of the movement of the piston 75, and the volume (volume) of the oil chamber 74' accompanying the reciprocation of the piston 75. Accordingly, hydraulic oil is drawn from the tank 10 into the oil chamber 74 'or discharged from the oil chamber 74' into the tank 10.

  The oil chamber 72 of the second embodiment constitutes the drive chamber of the present invention, the oil chamber 71 'constitutes the communication chamber of the present invention, and the oil chamber 74' constitutes the open chamber of the present invention.

  Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and any changes or additions may be made without departing from the scope of the present invention. Be

  For example, in the first embodiment, in the initial state in which the accumulator 8 is not preloaded, the electromagnetic switching valve 6 is in a demagnetized state, and piping is provided so as to allow direct communication from the hydraulic pump 2 to the accumulator 8. For example, as shown in FIG. 3 as a modified example of the first embodiment, the communication mode of piping in the demagnetized / excited state of the electromagnetic switching valve 6 ′ may be disposed reversely to the first embodiment. With the valve 6 ′ in an energized state, piping may be provided so that the direct line from the hydraulic pump 2 to the accumulator 8 is in communication.

  Similarly, as shown in FIG. 4 as a modification of the second embodiment, the communication mode of piping in the demagnetized / excited state of the electromagnetic switching valve 6 ′ may be arranged reverse to that of the second embodiment. It is also possible to pipe such that a direct pipe line from the hydraulic pump 2 to the accumulator 8 is in communication when the switching valve 6 'is in an excited state.

  Further, as shown in FIG. 5 as another modification of the second embodiment, biasing means 76 comprising a spring or the like for biasing the piston 75 toward the oil chamber 72 is provided in the oil chamber 74 'of the pressure booster 7. It may be provided. In this manner, the biasing means 76 biases the piston 75 toward the oil chamber 72, thereby moving the piston 75 moved toward the communication chamber to the oil chamber 72 early and reliably, and for the next operation of the piston 75. It can be equipped.

  Also, as described above, the biasing means 76 is provided in the oil chamber 74 'where the pressure is always released, so that the biasing means 76 applies the biasing force to the piston 75 without being affected by the pressure of the hydraulic fluid. be able to.

  In the first and second embodiments, a hydraulic device using hydraulic oil has been described as an example of the fluid pressure control device, but it goes without saying that the present invention can be applied to all liquids and gases other than oil. The present invention can also be applied to an apparatus using a water pressure device or a pneumatic device.

  Furthermore, in the first and second embodiments, the switching valves 6, 6 'and 9 have been described as electromagnetic valves. However, the present invention is not limited to this. For example, manual switching valves may be used.

1 Drive mechanism 2 Hydraulic pump (pump)
3 Main pipe 4 Hydraulic pressure supplied circuit 5 Branch pipe 6 Solenoid switching valve (switching valve)
7 Pressure booster 8 Accumulator (pressure accumulator)
Reference Signs List 10 tank 12 check valve 13 switching pipe 14 check valve 15 high pressure pipe 17 check valve 18 check valve 30 switching pipe 32 switching pipe 71 oil chamber (open chamber)
72 Oil chamber (drive chamber)
73 case 74 oil chamber (communication chamber)
75 piston 71 'oil chamber (communication chamber)
74 'oil room (open room)
76 urging means 101 drive mechanism 102 hydraulic pump 104 hydraulic pressure supplied circuit 105 branch pipe 106 switching valve 108 pressure accumulator 110 tank 131 suction pipe 170 pressure accumulator 171 oil chamber 172 oil chamber 173 case 174 oil chamber 175 piston

Claims (4)

A pump for discharging a working fluid, a pressure booster capable of increasing the pressure by discharging the working fluid discharged from the pump , an accumulator for storing pressure the working fluid discharged from the pressure booster, and a working fluid for the pump A fluid pressure control device comprising at least a tank for supplying
The pressure booster includes a drive chamber for introducing a working fluid discharged by the pump, a communication chamber in communication with the pressure accumulator and capable of discharging a working fluid by increasing the discharge pressure of the pump, and a pressure of the working fluid A piston for variably moving the volumes of the drive chamber and the communication chamber, and an open chamber for always communicating with the tank and releasing the pressure regardless of the movement of the piston;
A fluid pressure control device comprising a switching valve capable of switching a flow path of working fluid to the drive chamber or the communication chamber between the pump and the pressure increasing device. The fluid pressure control device according to claim 1 , further comprising a check valve for allowing the flow of the working fluid from the pressure intensifier to the pressure accumulator, between the pressure intensifier and the pressure accumulator. . The fluid pressure control device according to claim 1 or 2 , wherein the pressure intensifying device further includes biasing means for biasing the piston toward the drive chamber. The fluid pressure control device according to claim 3 , wherein the biasing means is provided in the open chamber.

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