JPH11141451A - Hydraulic pressure converting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform effective operation and prevent heat generation due to power loss. SOLUTION: A first port 11 and a second port 12 are formed in a valve plate 8 for dividing pressure fluid to the suction and discharge, and the second port 12 is further divided into an inside port 12a and outside port 12b. A plurality of piston sliding holes 5 are sorted according to the holes communicated to the first port 11 and the outside port 12b and the holes communicated to the first port 11 and the inside port 12a. Thrust force works to a piston by the introduction of pressure fluid to the first port 11, resulting in the rotation of a cylinder block, and the pressure of an output port works to the inside port 12a, making torque work in the direction opposing to the rotation direction of the cylinder block. The condition to balance the rotation torque can be determined by the distribution ratio of the inside port 12a to the outside port 12b. Therefore, pressure can be boosted by the distribution ratio of the inside port 12a and the outside port 12b, and if the distribution ratio is reversed, pressure can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pressure transformer which can be used as a pressure booster or a pressure reducer.

[0002]

2. Description of the Related Art A conventional hydraulic pressure transformer used as a pressure intensifier is, for example, used in a crusher of a construction machine in combination with a switching valve. In some hydraulic pressure transformers, an input port communicating with a large-diameter piston is connected to a hydraulic pressure source, and an output port communicating with a small-diameter piston is connected to a driving actuator of the crusher.

[0003] In this hydraulic pressure transformer, in the pressure increasing mode, the hydraulic fluid from the hydraulic source acts on the large-diameter piston side, whereby the small-diameter piston is displaced, so that the hydraulic fluid is sent from the output port to the driving actuator. It is. This operation is repeatedly performed by operating the switching valve. During this operation, the flow rate of the pressurized liquid discharged from the output port decreases with respect to the flow rate input to the large-diameter piston side due to the pressure receiving area ratio between the large-diameter piston side and the small-diameter piston side. The pressure is increased by an amount corresponding to the reciprocal of the pressure receiving area ratio.

On the other hand, in the case of an industrial machine, for example, when operating a plurality of actuators from a hydraulic pressure source, the same pressure may not always be required for each of the actuators. In such a case, the pressure of the hydraulic pressure source is set to the discharge pressure in accordance with the actuator that requires the highest pressure among the plurality of actuators. On the other hand, the pressure in the supply pipe is reduced by using a pressure reducing hydraulic pressure transformer.

[0005] Such a decompressor is constituted by, for example, a pilot portion of an upper cover for setting pressure, and a main body including a spool and a spring, and adjusts a spring force of a poppet provided in the pilot portion. In some cases, the set pressure is adjusted by the pressure. In this pressure reducer, the maximum pressure at the secondary pressure outlet is controlled by the vertical movement of the spool. When the pressure at the secondary pressure outlet is lower than the set pressure, the pilot section does not operate and the circuit is opened by the force of the spring. Therefore,
The pressure fluid at the primary pressure inlet has almost no resistance and the entire flow flows to the secondary pressure outlet. At this time, the upper and lower surfaces of the spool are in a hydraulic equilibrium state.

[0006]

However, in the case of the above-mentioned conventional hydraulic pressure-increasing device for increasing the pressure,
Since the pressure output to the actuator is increased by repeatedly performing the operation of switching the position of the switching valve, the operation is discontinuous.

[0007] In the case of the above-described conventional hydraulic pressure-transforming apparatus for decompressing, the pressure from the primary pressure inlet is reduced to 2
Since the amount of pressurized liquid flowing out to the next pressure outlet is adjusted by the spool, power is lost at the spool (valve element), so energy is wasted and energy is not used efficiently. there were. Then, since all of the loss results in heat generation, there is a possibility that the operating oil is deteriorated.

That is, the power loss is expressed as EL (W), the primary pressure at the primary pressure inlet is P1 (Pa), and the secondary pressure at the secondary pressure outlet is P (P).
Assuming that the flow rate is 2 (Pa) and the passing flow rate is q (m ³ / s), the power loss EL is expressed by the following equation, and the reduced pressure of P1 -P2 is all lost and generates heat. EL = q (P1 -P2)

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an efficient hydraulic pressure transformer capable of continuously outputting power and not generating heat due to power loss caused by a valve body. The purpose is to provide.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a plurality of piston sliding holes which are rotatably held at predetermined intervals in an annular direction around a rotation axis thereof. A cylinder block formed substantially in parallel,
A plurality of pistons respectively fitted in each piston sliding hole so as to be able to move forward and backward, a swash plate for converting the rotation of the cylinder block into each stroke of the piston forward and backward, and each of the forward and backward movement of the piston An axial piston type hydraulic pressure transformer including a valve plate having each port for distributing suction and delivery of pressure fluid in accordance with a stroke is configured as follows.

That is, a port of the valve plate is connected to a first port for sucking the hydraulic fluid and a second port for sending the hydraulic fluid along an annular direction in which the plurality of piston sliding holes are arranged. And one of the first port and the second port is further divided into two in a radial direction orthogonal to the annular direction to form an inner port and an outer port. A piston having a first hole that allows the piston sliding hole to communicate with a port of the first port and the second port that is not divided into two in the radial direction and the outer port. The hydraulic pressure transformer is configured by dividing the sliding hole into a piston sliding hole having a second hole for communicating the piston sliding hole with the port on the side not divided in the radial direction and the inside port.

[0012] Further, the pressure booster system using the hydraulic pressure transformer may be configured such that a port of the first port and the second port which is not divided into two in the radial direction is connected to an input pipe.
While communicating the above inner ports with the output piping,
It is constituted by connecting the outer port to the tank.

Further, in the pressure reducing device system using the above-mentioned hydraulic pressure transforming device, a port of the first port and the second port which is not divided into two in the radial direction is used as an output pipe, and the inside port is used as an input port. It is constituted by communicating with the piping and communicating the outer port with the tank.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a piston sliding hole superimposed on a valve plate provided in a hydraulic pressure transformer according to the present invention. FIG. 2 is a plan view showing a cylinder block in which the piston sliding hole is also formed. FIG. 3 is a sectional view showing an axial piston type hydraulic pressure transformer having the cylinder block.

An axial piston type hydraulic pressure transformer 1 shown in FIG.
Are rotatably held by bearings 4 so that the cylinder block 3 rotates about a rotation axis CL. As shown in FIG. 2, the cylinder block 3 is provided with a plurality of (ten in this example) piston sliding holes 5 at predetermined intervals in an annular direction around the rotation axis CL as shown in FIG. Each is formed parallel to the axis CL.

A piston 6 is fitted in each piston sliding hole 5 so as to be able to move forward and backward (reciprocate). A swash plate 7 is provided on the left side of the cylinder block 3 in FIG. 3 to convert the rotation of the cylinder block 3 into forward and backward strokes of a piston 6. The right side of the cylinder block 3 in FIG. 3 is in sliding contact with the right end face of the cylinder block 3 to distribute the suction of the hydraulic fluid and the delivery of the hydraulic fluid in accordance with the forward and backward strokes of the piston 6. A valve plate 8 having each port described below is provided.

The tip of each piston 6 is formed in a spherical shape, and each spherical portion is rotatably fitted into a piston shoe 9, and the rotation of the cylinder block 3 causes the piston shoe 9 to rotate.
Slides on the swash plate 7. The piston shoe 9 is pressed against the swash plate 7 via a central bearing 14 by the urging force of a spring 13.

As shown in FIG. 1, the valve plate 8 sucks the above-mentioned pressure fluid along an annular direction in which a plurality of piston sliding holes 5 are arranged, as shown in FIG. The first port 11 and the second port 12 for sending out the pressurized liquid are formed separately, and the second port 12 (which may be on the first port 11 side) is further provided. It is also divided into two in the radial direction (radial direction) orthogonal to the annular direction in which the piston sliding holes 5 are arranged, to form three inner ports 12a and one outer port 12b.

The first port 11 and the second port 12
The inside port 12a of the first port 11 has a shape close to an arc-shaped long hole, and the first port 11 is formed to have a larger hole width than the inside port 12a of the second port 12. The outer port 12b of the second port 12 is formed by partially cutting out the outer peripheral side of the valve plate 8 in an arc shape.

On the other hand, as shown in FIG. 1, the plurality of piston sliding holes 5 of the cylinder block 3 shown in FIG.
A piston sliding hole 5A (FIG. 2) having an arc-shaped first hole 15 that allows the piston sliding hole 5 to communicate with the outer port 12b at different rotational positions; a first port 11 and a second port 12; 2 having an arc-shaped second hole 16 for communicating the piston sliding hole 5 with the inner port 12a of the piston sliding hole 5 at different rotational positions (hereinafter simply referred to as the piston sliding hole 5 if not specified). ).
The first block formed on the cylinder block 3
The positions of the holes 15 and the second holes 16 are formed at regular intervals in the annular direction as shown in FIG. 4 when the cylinder block 3 is viewed from the back side.

When the hydraulic pressure transformer 1 described with reference to FIG. 3 is used in a pressure booster system, the first port 11 is connected to the input port on the input pipe side as shown in FIG. The inner port 12a of the port 12 communicates with the output port on the output pipe side, and the outer port 12b communicates with the tank 17.

In this way, when the hydraulic fluid is introduced from the input port into the two first ports 11, 11 of the hydraulic pressure transformer 1, the pressure of the hydraulic fluid is applied to the right end of the piston 6 in FIG. By acting on the surface, the pushed piston 6 pushes the swash plate 7 leftward in the figure via the piston shoe 9, so that the thrust acting in the axial direction of the piston 6 causes the cylinder block 3 to rotate along the rotation axis. It is converted into a rotational torque that rotates around CL.

The pressure fluid introduced from the two first ports 11 of the valve plate 8 is supplied to the cylinder block 3.
For example, when the first port 11 is in the position shown in FIG. 1, the two first ports 11, 11 are provided with the first hole 15 or the second hole The four pistons 6 fitted in the corresponding four piston sliding holes 5 are simultaneously communicated through the holes 16.
Is applied to the cylinder block 3 so that a rotational torque T1 for rotating the cylinder block 3 acts on the cylinder block 3 to rotate the cylinder block 3 as described above.

The pressure liquid introduced into each piston slide hole 5 from the first port 11 is diverted from the inner port 12 a of the second port 12 to the output port and from the outer port 12 b to the tank 17. Is discharged. At this time, when an actuator is connected to the output port, a pressure corresponding to the load of the actuator acts on the inner port 12a of the second port 12 thereby.

When the cylinder block 3 is located at the position shown in FIG. 1, for example, the three inner ports 12a are connected to the two piston sliding holes 5 as shown in FIG. The two pistons 6 fitted in the corresponding two piston sliding holes 5 are applied with a pressure corresponding to the load of the actuator in the axial direction. As a result, the thrust generated in the piston 6 causes the cylinder block 3 to rotate in the direction opposite to the rotational torque T1.
2 works.

The rotation torque T2 can rise to a point where the rotation torque T1 is balanced. The cylinder block 3 continues to rotate until the rotation torque T2 is balanced with the rotation torque T1, and then stops. The ratio of “pressure on the input side / pressure on the output side”, which is a condition for balancing the rotational torque, is determined by the flow rate of the pressurized liquid flowing from the first port 11 into the piston sliding hole 5 of the cylinder block 3 and the second flow rate. The flow rate of the second port 12 is equal to the ratio of the flow rate flowing out of the inner port 12a of the second port 12 to the flow rate of the input side / flow rate on the output side.
Is determined by the distribution ratio between the inner port 12a and the outer port 12b divided into two in the radial direction.

In the hydraulic pressure transformer 1, when the pressure acting on the inner port 12a of the second port 12 is Pb and the pressure acting on the first port 11 is Pa, the following equation is obtained. Is established. Therefore, the hydraulic pressure transformer 1 can function as a pressure intensifier. Pb = 2Pa

Next, a description will be given of a case where a pressure reducing device system is configured using the hydraulic pressure transforming device 1 of FIG. In this case, as shown in FIG. 6, the first port 11 of the first port 11 and the second port 12 which is not divided into two in the radial direction is used as the output port on the output pipe side, and the second port 1
The two inner ports 12a communicate with the input ports on the input piping side, and the outer ports 12b communicate with the tank 17.

In this way, the hydraulic fluid flows from the input port to the inner port 12a of the second port 12 of the hydraulic pressure transformer 1.
The hydraulic fluid sucked from the tank 17 is introduced into the piston sliding hole 5 from the outer port 12b through the first hole 15 through the second hole 16 of the cylinder block 3. As a result, the pressure of the pressurized fluid and the hydraulic fluid is increased by the piston 6 (see FIG. 3).
Act on. The thrust acting in the axial direction of the piston 6 is converted by the swash plate 7 into a rotational torque T3 for rotating the cylinder block 3 about the rotation axis CL, and the cylinder block 3 is driven in the opposite direction to that of the above-described pressure intensifier. To rotate.

Then, the hydraulic fluid and the hydraulic fluid introduced into each piston sliding hole 5 from the inner port 12a and the outer port 12b of the second port 12 merge into the two first ports 11 , 11 to the output port. At that time, if an actuator is connected to the output port, the two first ports 11,
A pressure corresponding to the load of the actuator acts on 11.

When the cylinder block 3 is located at the position shown in FIG. 6, for example, the two first ports 11 are connected to four first ports 11 as shown in FIG. Since the piston slide holes 5 are simultaneously communicated through the first holes 15 or the second holes 16, the four pistons 6 fitted in the corresponding four piston slide holes 5 are axially displaced. A pressure corresponding to the load of the actuator acts, and a thrust generated on the piston 6 by the pressure acts on the cylinder block 3 with a rotational torque T4 for rotating the cylinder block 3 in a direction opposite to the rotational torque T3.

The rotation torque T4 can rise to a point where the rotation torque T3 is balanced with the rotation torque T3. The cylinder block 3 continues to rotate until the rotation torque T4 is balanced with the rotation torque T3, and then stops. The ratio of “pressure on the input side / pressure on the output side”, which is a condition for balancing the rotational torque, is such that the inner port 12 a of the second port 12 is provided in the piston sliding hole 5 of the cylinder block 3.
Is equal to the ratio of the flow rate of the pressurized liquid flowing out of the first port 11 to the flow rate flowing out of the first port 11, that is, the ratio of "flow rate on the input side / flow rate on the output side" is the same as in the case of the pressure intensifier described above. And is determined by the distribution ratio between the inner port 12a and the outer port 12b that are divided into two in the radial direction of the second port 12 described above. Therefore, the hydraulic pressure transformer 1 can be used as a pressure reducer that can reduce the pressure according to the distribution ratio.

As described above, the hydraulic pressure transformer 1 described with reference to FIG. 3 can be used to construct a pressure booster system,
In any case, even if a pressure reducing device system is configured, output can be continuously obtained, but there is almost no loss. In addition, in the above-mentioned hydraulic pressure transformer 1, as is clear from the total number of piston sliding holes 5 shown in FIG. 2, the total number of pistons 6 fitted in the piston sliding holes 5 is ten, The case where the transformation ratio is set to 2 to 1 by using five of them for suction of the pressurized liquid and using the remaining five for delivery is described.

However, the total number of the pistons 6 is 8
If the number of pistons 6 used for sucking and sending out the hydraulic fluid is set to two and six (the pressure is reversed when the pressure is increased and the pressure is reduced), the above-mentioned transformation ratio is 3: 1 or 3: 2. Of course, it can be done. Further, if the total number of the pistons 6 is further increased, it is possible to provide a hydraulic pressure transformer capable of obtaining a variable pressure ratio of various integer ratios, and if the diameter of the piston 6 is appropriately changed, It is possible to provide a hydraulic pressure transformer having a variable pressure ratio according to the purpose.

FIG. 7 is a hydraulic circuit showing a part of a hydraulic circuit when the hydraulic pressure transformer of FIG. 3 is used in a crusher of a construction machine. In this hydraulic circuit, the hydraulic pressure transformer 1 described with reference to FIG. 3 is disposed in parallel in a pipeline between a hydraulic pump (hydraulic pressure source) and a cylinder 21 serving as an actuator for driving the crusher. By switching the position of the switching valve 20 provided in the pipeline to the position shown in the drawing, the normal system line pressure of 35 MPa is reduced to 70 M through the hydraulic pressure transformer 1.
Increase the pressure to the hydraulic line of Pa (when the transformation ratio is 1: 2),
The increased pressure fluid is supplied to the port 2 on the head side of the cylinder 21.
1a, the port 2 on the rod side of the cylinder 21
The working fluid discharged from 1b is returned to another port of the hydraulic pump.

FIG. 8 is a hydraulic circuit showing a part of a hydraulic circuit when the hydraulic pressure transformer shown in FIG. 3 is used as a device for moving a table of a machine tool. In this hydraulic circuit, a check valve 32 and an electromagnetic control pilot operation valve 30 are arranged in series in a pipe between a hydraulic pump (hydraulic pressure source) and a cylinder 31 for moving a table of a machine tool. Check valve 32
FIG. 3 shows a line between
The inside port 12a of the second port 12 of the hydraulic pressure transformer 1 described in the above section is communicated.

Further, the first port 11 of the hydraulic pressure transformer 1 is connected to a valve 34 via a check valve 33, and the pressure fluid via the valve 34 is introduced into a port 35a on the rod side of the clamp cylinder 35. The hydraulic fluid discharged from the port 35b on the head side of the clamp cylinder 35 is
Through the tank 36. When the clamp cylinder 35 is moved to the opposite side, the position of the valve 34 is switched.

In such a hydraulic system, the cylinder 31 for moving the table may need a sufficient thrust, so that the pressure of the hydraulic fluid introduced therein is, for example, 7 MPa.
It is necessary to increase the pressure up to
In FIG. 8, other actuators, which are not shown because they are complicated, can always be operated at a pressure of about 3.5 MPa.

Therefore, in the hydraulic system shown in FIG. 8, by arranging the hydraulic pressure transforming device 1 in the above-described pipe, a 7-MPa hydraulic fluid is applied to the cylinder 31 and the hydraulic fluid is applied to the clamp cylinder 35 and the like. By reducing the pressure of the pressurized liquid to 1/2 and setting the upper limit to 3.5 MPa, the pipe line can be protected. Also in this case, the loss is not caused as in the case of using the conventional pressure reducing valve, so that the efficiency is high, and since there is no heat generated by the loss, the deterioration of the hydraulic oil due to the heat is also prevented. be able to.

It should be noted that the hydraulic pressure transformer according to the present invention uses the cylinder block 3 and the valve plate 8 described with reference to FIGS. 1 and 2 and the like even when the mechanism of the oblique shaft type piston pump and the mechanism of the radial piston pump are used. By using the configured distribution valve mechanism, the same effect as the above-described hydraulic pressure transformer 1 can be obtained. It is particularly effective when the hydraulic pressure transformer according to the present invention is used in a pressure reducing system using an accumulator.

[0041]

As described above, according to the present invention, a continuous output can be obtained, so that the actuator can be operated smoothly, and there is no power loss due to the valve body, so that the efficiency is high and the power loss is high. Because there is no heat generation, there is no deterioration of hydraulic oil.

[Brief description of the drawings]

FIG. 1 is a plan view showing a piston sliding hole superimposed on a valve plate provided in a hydraulic pressure transformer according to the present invention.

FIG. 2 is a plan view showing a cylinder block in which a piston sliding hole is formed.

FIG. 3 is a structural view showing an axial piston type hydraulic pressure transformer having the cylinder block in a sectional state.

FIG. 4 is a view of the cylinder block of FIG. 2 as viewed from the back side.

FIG. 5 is a plan view showing the shape of the valve plate of FIG. 1 in detail.

FIG. 6 is a plan view similar to FIG. 1 showing a connection relation to an input / output port and a tank when a hydraulic pressure transformer of FIG. FIG.

FIG. 7 is a hydraulic circuit diagram showing a part of a hydraulic circuit when the hydraulic pressure transformer of FIG. 3 is used in a crusher of a construction machine.

FIG. 8 is a hydraulic circuit diagram showing a part of a hydraulic circuit when the hydraulic pressure transformer of FIG. 3 is used in a device for moving a table of a machine tool.

[Explanation of symbols]

 1: hydraulic pressure transformer 3: cylinder block 5: piston sliding hole 6: piston 7: swash plate 11: first port 12: second port 12a: inner port 12b: outer port 15: first hole 16 : Second hole 17, 36: Tank CL: Rotation axis

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takemasa Takeshi 2-16-16 Minami Kamata, Ota-ku, Tokyo Inside Tokimec Co., Ltd. (72) Inventor Hiroto Maekawa 2-16-46 Minami Kamata, Ota-ku, Tokyo Inside Tokimec Co., Ltd.

Claims (3)

[Claims] 1. A cylinder block which is rotatably held and has a plurality of piston sliding holes formed at predetermined intervals in a circular direction around a rotation axis thereof and substantially parallel to the rotation axis.
A plurality of pistons respectively fitted in the piston sliding holes so as to be able to move forward and backward, a swash plate for converting the rotation of the cylinder block into forward and backward strokes of the piston, An axial piston type hydraulic pressure transformer including a valve plate having ports for distributing suction and delivery of pressure liquid in accordance with each retreat stroke, wherein a port of the valve plate is connected to the plurality of pistons. A first port for sucking the pressure fluid and a second port for delivering the pressure fluid are divided along the annular direction in which the sliding holes are arranged, and the first port and the second port are separated from each other. One of the ports is further divided into two parts in a radial direction orthogonal to the annular direction to form an inner port and an outer port, and the plurality of piston sliding holes of the cylinder block are connected to the first port. A piston sliding hole having a first port for communicating the piston sliding hole with the port of the second port that is not divided in the radial direction and the outer port; A hydraulic pressure transformer, wherein the hydraulic pressure transformer is divided into a port and a piston sliding hole having a second hole communicating the piston sliding hole with the inner port. 2. A pressure booster system using the hydraulic pressure transformer according to claim 1, wherein a port of the first port and the second port which is not divided into two in the radial direction is an input pipe. And a pressure booster system in which the inside port is connected to an output pipe and the outside port is connected to a tank. 3. A pressure reducing system using the hydraulic pressure transformer according to claim 1, wherein a port of the first port and the second port that is not divided in the radial direction is used as an output pipe. A pressure reducing device system in which the inside port is connected to an input pipe and the outside port is connected to a tank.