JP2002048105A - Cylinder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder device that has a cylinder and a fluid pressure source equipped with a hydraulic pump, an electric motor, control valves, and a reservoir, furthermore that does not need any space around the cylinder for the fluid pressure source. SOLUTION: This cylinder device expands the cylinder by supplying a working fluid into a cylinder chamber and exhausting it from the chamber. The working fluid is delivered from the reservoir by a hydraulic pump driven by an electric motor. Also, the device is divided into an upper and lower chamber by a block member 4 that is set in the middle of a hollow inner tube 2. The upper chamber sets the electric motor 5. The lower chamber is used for the reservoir storing the working fluid. The block member 4 has a hydraulic pump 7 driven by the electric motor 5, a suction valve 9 set between the hydraulic pump 7 and the reservoir 6, and a cylinder control valve 8 set between the hydraulic pump 7 and the cylinder A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pressure source, an electric motor for driving the hydraulic pressure pump, a hydraulic pressure source comprising a control valve and a reservoir tank arranged on the suction side and the discharge side of the hydraulic pressure pump, and a cylinder. Are related to a cylinder device.

[0002]

2. Description of the Related Art Conventionally, as a cylinder device in which this kind of hydraulic pressure source and a cylinder are integrated, for example, Japanese Patent No. 2824
No. 659 is disclosed.

According to this patent, a block member having a built-in hydraulic pump and valves and having a passage communicating with each chamber of a cylinder, a reservoir tank mounted on one of the block members, and mounted on the other. A hydraulic pressure source is constituted by the electric motor. In this hydraulic pressure source, a cylinder device is configured by attaching the block member to a side portion of the cylinder.

[0004]

However, in such a conventional cylinder device, since the hydraulic pressure source is mounted on the side of the cylinder, it is difficult to dispose the hydraulic pressure source around the cylinder. Since the installation space is required and the arrangement is restricted, there is a problem that the method cannot be applied when the installation space is not sufficient.

When a long stroke and a large thrust (large piston pressure receiving area) are required for a cylinder, it is necessary to supply and discharge a large amount of hydraulic fluid, and the reservoir tank becomes large in size. There was a problem that a large installation space was required.

The present invention has been made in view of the above problems, and has as its object to provide a cylinder device that does not require a space for a hydraulic pressure source around the cylinder.

[0007]

SUMMARY OF THE INVENTION A first aspect of the present invention is a cylinder apparatus in which a hydraulic pump driven by an electric motor supplies and discharges a hydraulic fluid in a reservoir tank to a cylinder chamber to extend and retract the cylinder. A piston fixed to the tube and the inner tube is slidably housed in the cylinder tube to form a cylinder chamber on at least one side of the piston, and a block member provided in the middle of the inner tube is used to divide the inside of the inner tube. The chamber is divided into two chambers, one of which is provided with an electric motor and the other of which is a reservoir tank storing working fluid, wherein the block member is driven by an electric motor, and a hydraulic pump is provided between the hydraulic pump and the reservoir tank. A cylinder control valve interposed between the suction valve and the hydraulic pump interposed in the cylinder chamber and the cylinder chamber. And it said that it has set.

In a second aspect based on the first aspect, the reservoir tank is disposed in a chamber to which a piston is fixed in an inner tube partitioned by the block member, and the electric motor is partitioned by the block member. It is arranged in another chamber in the inner tube that has been set.

According to a third aspect of the present invention, in the first or second aspect, the cylinder control valve and the cylinder chamber communicate with each other through a pipe passage disposed between the block member and the piston through a reservoir tank. And

According to a fourth aspect of the present invention, in any one of the first to third aspects, the cylinder control valve includes substantially parallel first and second passages communicating with a plurality of cylinder chambers, respectively. , A first chamber communicated with one port of the hydraulic pump, a check valve communicating the first chamber with the first passage by a pressure of the first chamber, and a check valve arranged between the first passage and the second passage. A first valve in which a pilot check valve for opening a second passage to a drain port by a pressure of the first chamber is arranged in series; and a first valve disposed between the first and second passages, A second chamber connected to the other port and a check valve for connecting the second chamber to the second passage by the pressure of the second chamber; and a first passage to the drain port by the pressure of the second chamber. The pilot check valve to be opened is arranged in series with the second Characterized in that it is composed of a lube.

In a fifth aspect based on any one of the first to third aspects, the cylinder control valve is disposed adjacent to the first passage communicating with one of the cylinder chambers and the first passage. The first chamber communicated with one port of the hydraulic pump and the first chamber is moved to the first chamber by the pressure of the first chamber.
A first valve formed of a check valve communicating with the first passage, and a second chamber disposed adjacent to the first passage and communicating with the other port of the hydraulic pump. And a second valve comprising a pilot check valve for opening the first passage to the drain port.

In a sixth aspect based on any one of the first to third aspects, the cylinder control valve is disposed adjacent to the first passage communicating with one of the cylinder chambers and the first passage. A first chamber connected to one port of the hydraulic pump, a check valve for connecting the first chamber to the first passage by the pressure of the first chamber, and a check valve adjacent to the first chamber. A second chamber disposed and communicated with the other port of the hydraulic pump; and a pilot spool disposed between the first and second chambers and opening the check valve by the pressure of the second chamber. It is characterized by having.

[0013]

According to the first aspect of the invention, the hydraulic pump and the electric motor for driving the hydraulic pump, the reservoir tank, the suction valve, and the cylinder control valve are configured to be housed in the hollow portion of the inner tube of the cylinder. Therefore, a space for the hydraulic pressure source is not required outside the cylinder device, and the installation space for the cylinder device can be reduced, thereby facilitating the installation. Therefore, there is an effect that can be applied even when the installation space is not enough.

When a long stroke or a large thrust (large piston pressure receiving area) is required for the cylinder, the reservoir tank is enlarged to supply and discharge a large amount of hydraulic fluid, but the piston pressure receiving area is increased. Since the inner diameter of the minute inner tube is increased and the internal space volume can be increased, the reservoir tank volume can be easily increased, and no space is required around the cylinder device.

Furthermore, since the hydraulic pressure source is housed in the cylinder, the cylinder device itself can have a clean appearance without a large protrusion, and the commercial value can be enhanced in terms of design.

In addition, the inner tube is divided into two chambers by a block member, and an electric motor is arranged in one of the chambers and the other chamber is formed as a reservoir tank. Can be completely separated by the block member, and a highly safe cylinder device can be provided.

According to the second aspect of the present invention, since the electric motor is disposed in the chamber on the side opposite to the side on which the piston of the inner tube is fixed, it is easy to pull out the lead wire connected to the external control device. It is.

Further, the working fluid does not pass through the chamber on the electric motor side divided by the block member at all, so that the electric motor can be easily protected.

According to the third aspect of the present invention, since the relative positional relationship between the block member fixed to the inner tube and the piston does not change, the pipe penetrating through the reservoir tank and disposed between the hydraulic pump and each cylinder chamber is provided. Piping can be easily performed by the passage.

In the fourth aspect, the first and second passages and the first and second valves of the cylinder control valve can be arranged in substantially the same plane, so that the block member can be made thinner in the axial direction, and a large electric motor can be used. Space for installing a motor and a large reservoir tank can be made.

According to the fifth aspect, the effect of the fourth aspect is of course obtained. However, the first and second aspects of the fourth aspect of the present invention, which face the second passage of the cylinder control valve, are also provided.
The check valve and pilot check valve of the second valve are removed except for the pilot spool, and the first and second valves are replaced.
If the valve is closed from the second passage side with a plug or the like, the operation can be performed without any change in the structure of the block member, and the hydraulic circuit can be easily changed.

Further, if the second passage itself is not machined without being blocked by the plug, the construction of the cylinder control valve can be further simplified without the need for a plug.

According to the sixth aspect of the present invention, the effect of the fifth aspect is of course provided, and furthermore, the cylinder control valve according to the fifth aspect of the present invention is disposed at the intersection of the first passage and the second valve. The pilot check valve which has been removed is removed except for the pilot spool, and instead the second valve is closed with a plug or the like from the first passage side and the second valve is closed.
By introducing a change in the hydraulic pressure of the second chamber of the first valve into the chamber in which the drain port (the port is closed) of the first valve is open, a slight change is made to the passage structure of the block member. It can be implemented only by adding, and the change of the hydraulic circuit is easy.

Of course, if the hydraulic pressure from the other port of the hydraulic pump is supplied from the beginning to the portion where the drain port of the first valve was provided without being blocked by the plug, the second valve itself Therefore, the configuration of the cylinder control valve can be simplified.

The speed of the cylinder in both directions of expansion and contraction can be variably controlled according to the rotation speed or the discharge flow rate of the hydraulic pump.

[0026]

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

FIGS. 1 to 6 show a first embodiment of the present invention. FIG. 1 is a sectional view showing an overall structure, FIG. 2 is a sectional view showing a structure of piping to a cylinder, and FIG. FIG. 1 is a sectional view taken along the line III-III of FIG. 1 showing the configuration of a cylinder control valve disposed between the pump and the cylinder. FIGS. 4 and 5 are views showing the configuration of a suction valve disposed between the hydraulic pump and the reservoir tank. FIG. 6 is a hydraulic circuit diagram.

In FIG. 1, reference numeral 1 denotes a cylinder tube, the bottom of which is closed by a head cover 1a, and an inner bearing 2 which functions as a piston rod is slidably guided by an upper bearing 1b.

A piston 3 fixed to the distal end of the inner tube 2 is slidably fitted in the cylinder tube 1 to form one cylinder chamber A between the piston 3 and the head cover 1a. The other cylinder chamber B is formed between the bearing and the bearing 1b. The cylinder 10 is constituted by the cylinder tube 1, the inner tube 2 and the piston 3.

The end of the inner tube 2 opposite to the piston 3 is closed by a cap 2a, and the space in the inner tube 2 is divided into two chambers by a block member 4 fixed in the middle of the inner tube 2. The electric motor 5 is disposed in one chamber, and the reservoir tank 6 is formed in the other chamber.

The block member 4 is divided into block members 4a and 4b at a plane perpendicular to the cylinder axis, and a hydraulic pump 7 whose suction direction and discharge direction change in accordance with the rotation direction is arranged on the joint surface of the two. It is driven by the electric motor 5 via a shaft 7a passing through the member 4a.

In the block member 4a on the side of the electric motor 5, there is provided a cylinder control valve 8 for receiving the supply of the hydraulic fluid through the passage 4c or 4d from the hydraulic pump 7 and controlling the supply and discharge to the cylinder chambers A and B. Be placed. A suction valve 9 composed of a relief valve described later and a suction check valve described later is arranged on the block member 4b on the reservoir tank 6 side. Reference numerals 4e and 4f denote passages for discharge from the cylinder control valve 8 to the reservoir tank 6, and reference numeral 5a denotes a lead wire of the electric motor 5.

As shown in FIG. 2, the cylinder control valve 8
The cylinder chambers A and B communicate with each other through passages 4g and 4h provided in the block member 4, pipe passages 4i and 4j, and passages 3a and 3b provided in the piston. The passages 4k and 4m formed by pipes and the like from the cap 2a to the reservoir tank 6 are passages for injecting and discharging the hydraulic fluid in the reservoir tank 6, and are provided in the reservoir tank 6 when the cylinder 10 is extended and contracted. Normally, only one of the plugs 2b and 2c is closed so that air flows into and out of the chamber of the reservoir tank 6 according to the change in the volume of the hydraulic fluid.

As shown in FIG. 3, the cylinder control valve 8
Are first and second passages 4 both ends of which are closed by plugs.
The first passage 4p has a passage 4g communicating with one of the cylinder chambers A, and the second passage 4q has a passage 4h communicating with the other cylinder chamber B.

Intersecting with the first and second passages 4p and 4q, two lateral holes 4r and 4s are arranged, and a first valve 8r for operating the cylinder 10 in the extending direction is disposed in the lateral holes 4r and 4s.
And the second valve 8s for operating the cylinder 10 in the contraction direction
And are arranged.

The first valve 8r includes a pilot plug 8e
The first chamber 8g communicates with one port of the hydraulic pump 7 via a passage 4c, and the first chamber 8g
A check valve 8a is provided between the first passage 4p and the passage 4p. Further, the first chamber 8g is connected to the second passage 4
q and the pilot plug 8e and the check valve 8b
The pilot check valve 8q is configured to communicate the second passage 4q with the reservoir tank 6 via the chamber 8h and the passage 4e when the pilot check valve 8q is operated.

The second valve 8s has a pilot plug 8f
The second chamber 8j communicates with the other port of the hydraulic pump 7 via a passage 4d, and the second chamber 8j
A check valve 8d that allows the inflow to the second passage 4q is provided between the check valve 8d and the passage 4q. The second chamber 8j is connected to the first passage 4
between the pilot plug 8f and the check valve 8c
The pilot check valve 8p is configured to communicate the first passage 4p to the reservoir tank 6 through the chamber 8i and the passage 4f when the pilot check valve 8p is operated.

As shown in FIGS. 4 and 5, between the hydraulic pump 7 and the reservoir tank 6, the passages 4c and 4d of the block member 4b corresponding to the two ports of the hydraulic pump 7 are respectively provided with suction check valves 9a. , 9b and the suction pipes 9c, 9d. The passages 4c and 4d have relief valves 9e and 9f, respectively, which lower the internal pressure by releasing the hydraulic fluid to the reservoir tank 6 when the internal pressure is equal to or higher than a predetermined pressure. Then, the suction check valves 9a, 9b and the relief valves 9e, 9f
Thus, the suction valve 9 is constituted.

In the hydraulic circuit diagram of FIG.
a, 8d and a pilot check valve, 8p, 8q constitute a cylinder control valve 8, and a suction check valve 9
The suction valves 9a and 9b and the relief valves 9e and 9f constitute the suction valve 9. Also, one port 7 of the hydraulic pump 7
b communicates with the passage 4c and communicates with a chamber 8g upstream of the check valve 8a of the cylinder control valve 8, and the other port 7c of the hydraulic pump 7 communicates with the passage 4d and a chamber 8j upstream of the check valve 8d of the cylinder control valve 8. Is in communication with

Next, the operation will be described.

When the electric motor 5 is driven to rotate in one direction (cylinder extension direction) in order to extend the cylinder device,
The hydraulic pump 7 sucks the working fluid in the reservoir tank 6 from the other port 7c through the suction pipe 9d, the suction check valve 9b of the suction valve 9, and the passage 4d, and discharges it from the one port 7b. The discharged hydraulic fluid is introduced into the cylinder control valve 8 from the passage 4c,
In FIG. 3, the pilot check valve 8q is operated from the first chamber 8g to allow the other cylinder chamber B to pass through the passage 4h,
The hydraulic fluid is communicated with the reservoir 6 through the passage 4q, the chamber 8h, and the passage 4e, so that the hydraulic fluid can be discharged. At the same time, the discharged hydraulic fluid pushes open the check valve 8a from the chamber 8g, flows into one cylinder chamber A via the first passage 4p and the passage 4g, and extends the cylinder 10. If an excessive load is applied to the cylinder 10 during this operation, the pressure in the passage 4c tends to increase to a predetermined pressure or more, but the relief valve 9e provided in the passage 4c is opened to limit the pressure increase in the passage 4c. In addition, each part is prevented from being damaged due to excessive pressure rise.

When the electric motor 5 is rotated in the other direction (cylinder contraction direction) to contract the cylinder device, the hydraulic pump 7 is connected to one port via the suction pipe 9c, the suction check valve 9a, and the passage 4c. 7b
From the other port 7c. The discharged hydraulic fluid reaches the second chamber 8j of the cylinder control valve 8 from the passage 4d, and operates the pilot check valve 8p to cause the hydraulic fluid in one cylinder chamber A to pass through the passages 4g, 4p,
It can be discharged to the reservoir 6 through the chamber 8i and the passage 4f. At the same time, the hydraulic fluid in the second chamber 8j is supplied to the check valve 8
d is pushed open to flow into the other cylinder chamber B of the cylinder 10 through the passages 4q and 4h to contract the cylinder device.

In the cylinder device of the present embodiment, the electric motor 5, the reservoir tank 6, the hydraulic pump 7, the cylinder control valve 8 and the suction control valve 9 are housed in the hollow portion of the inner tube 2 of the cylinder 10. With this configuration, there is no need for a space for the hydraulic pressure source outside the cylinder device, and the installation space for the cylinder device can be reduced and the installation becomes easy. Therefore, there is an effect that can be applied even when the installation space is not enough.

When a long stroke or a large thrust (large piston pressure receiving area) is required for the cylinder 10, the reservoir tank 6 is enlarged to supply and discharge a large amount of hydraulic fluid, but the piston pressure receiving area is increased. Accordingly, the volume in the inner tube 2 is increased, so that the volume of the reservoir tank 6 can be easily increased, and no space is required around the cylinder device.

Further, since the hydraulic pressure source is housed in the cylinder device, the cylinder device itself can be provided with a clean appearance without a large protrusion, and the commercial value can be enhanced in terms of design.

In this embodiment, the inside of the inner tube 2 is divided into two spaces by the block member 4, and the electric motor 5 is arranged in one of the chambers and the other chamber is used as the reservoir tank 6. The space immersed in the hydraulic fluid and the electrical equipment space are completely separated by the block member 4, so that a highly safe cylinder device can be provided.

Since the electric motor 5 is disposed in the chamber on the side opposite to the side where the piston 3 of the inner tube 2 is fixed, it is easy to pull out the lead wire 5a connected to an external control device. It is.

Further, since the hydraulic fluid does not pass through the chamber on the side of the electric motor 5 partitioned by the block member 4 at all,
The protection of the electric motor 5 becomes easy.

Further, since the relative positional relationship between the block member 4 fixed to the inner surface of the inner tube 2 and the piston 3 fixed to the end of the inner tube 2 does not change, the hydraulic pump 7 and the cylinder chambers A, B also passes through the reservoir tank 6 and the block member 4 and the piston 3
Due to the pipe passages 4i and 4j suspended between them, an effect can be easily obtained without making a hole or the like in the cylindrical portion of the inner tube 2.

Further, in this embodiment, since the first and second passages 4p and 4q and the first and second valves 8r and 8s of the cylinder control valve 8 can be arranged in substantially the same plane, the block member 4 is Electric motor 5 that can be made thinner in the axial direction
And a space for providing a large reservoir tank 6.

FIGS. 7 to 9 show another embodiment of the present invention. As a cylinder device to which a load is constantly input from the load side in the contraction direction, the hydraulic fluid is supplied to and discharged from only one of the cylinder chambers. FIG. 7 is a cross-sectional view showing a configuration of piping to the cylinder and the like, FIG. 8 is a cross-sectional view of a cylinder control valve, and FIG. 9 is an overall hydraulic circuit diagram. The same parts as those in the above-described embodiment are denoted by the same reference numerals and described.

As shown in the hydraulic circuit of FIG. 9, the passages 4g and 4p communicating from one port 7b of the hydraulic pump 7 to one cylinder chamber A of the cylinder 10 and the passages 4g and 4p
, The other cylinder chamber B is opened to the atmosphere, the passage 4d from the other port 7c of the hydraulic pump 7 is closed halfway, and only the pilot pressure is set to the pilot pressure. The structure is transmitted to the check valve 8p. Note that there is no change in the configuration of the hydraulic pump 7 and the suction valve 9.

In FIG. 7, a passage 4g from the cylinder control valve 8 to one cylinder chamber A and a pipe passage 4i
And the other cylinder chamber B is the cylinder tube 2
Is opened to the atmosphere by a lateral hole 2d provided at the upper end side of the.

In the cylinder control valve 8 shown in FIG. 8, only the first passage 4p communicating with one cylinder chamber A of the cylinder 10 via the passage 4g is formed, and the second passage 4q is connected to the first passage 4q.
Portions opening to the lateral holes 4r and 4s arranged to intersect with the passage 4p are closed by plugs 8k and 8m. Other configurations are the same as those in FIG. 3, but will be described below for just in case.

The first valve 8r is connected to a first port 8g of the hydraulic pump 7 via a passage 4c.
And a check valve 8a for communicating the first chamber 8g to the first passage 4p by the pressure of the first chamber 8g.
The pilot plug 8e inserted in the side hole 4r
Is provided to define the first chamber 8g from the adjacent chamber 8h.

The second valve 8s is connected to the other port of the hydraulic pump 7 via a passage 4d.
j and a pilot check valve 8p that opens the first passage 4p to the drain port 4f by the pressure of the second chamber 8j.

In this embodiment, when the electric motor 5 is driven to rotate in one direction (cylinder extension direction) in order to extend the cylinder 10, the hydraulic pump 7 sends the hydraulic fluid in the reservoir tank 6 to the other port 7c. Port 7b
From the cylinder control valve 8 through the passage 4c.
The check valve 8a is opened to open the passage 4p.
And 4 g, and one cylinder chamber A of the cylinder 10
And the cylinder 10 is extended.

When the electric motor 5 is driven to rotate in the other direction (cylinder contraction direction) in order to contract the cylinder device from this state, the hydraulic pump 7 sucks the hydraulic fluid in the reservoir tank 6 from one port 7b and supplies the hydraulic fluid to the other port 7b. The gas is discharged from the port 7c to the passage 4d and introduced into the second chamber 8j of the cylinder control valve 8. And the pilot check valve 8p
Is opened, and one cylinder chamber A of the cylinder 10 communicates with the reservoir 6 via the passage 4g, the chamber 8i, and the passage 4f,
The cylinder 10 is contracted by an action force in a contraction direction such as a load. In this case, the contraction speed needs to be adjusted by, for example, providing an orifice in the passage 4f. In this case, the driving force required for the electric motor 5 may be a small amount necessary for increasing the pressure of the second chamber 8j and a small power.

This embodiment has the following features.

That is, the cylinder control valve 8 shown in FIG.
, The check valve 8d and the pilot check valve 8 of the first and second valves 8r and 8s facing the second passage 4q
If q is removed (the pilot spool 8e is left) and the first and second valves 8r and 8s are closed with plugs 8k and 8m from the second passage 4q instead, the structure of the block member 4 is not changed at all. It can be implemented and the hydraulic circuit can be easily changed.

Further, if the second passage itself is not machined without being blocked by the plug, the construction of the cylinder control valve can be further simplified without the need for a plug.

FIGS. 10 and 11 show still another embodiment of the present invention, in which the structure of a cylinder control valve of the same single-acting cylinder as that of the other embodiment is further simplified, and FIG. FIG. 11 is a sectional view showing a cylinder control valve arranged between the pump and the cylinder, and FIG. 11 is a hydraulic circuit diagram.

As shown in the hydraulic circuit of FIG. 11, a check valve 8a provided in the passages 4c and 4p from one port 7b of the hydraulic pump 7 to one cylinder chamber A is connected to the other port of the hydraulic pump 7. The pilot type check valve 8a is opened via the pilot spool 8e with the operating pressure from 7c.

As shown in FIG. 10, the cylinder control valve 8 has a first passage 4 p communicating with one cylinder chamber A,
A first chamber 8g disposed adjacent to the first passage 4p and communicated with one port 7b of the hydraulic pump 7, and the first chamber 8g is connected to the first passage 8g by the pressure of the first chamber 8g. A check valve 8a communicating with the first chamber 8g, a second chamber 8h disposed adjacent to the first chamber 8g and communicating with the other port 7c of the hydraulic pump 7, a first and second chamber 8g, 8h, and a pilot spool 8e that opens the check valve 8a by the pressure of the second chamber 8h.

In this embodiment, when the electric motor 5 is driven to rotate in one direction (cylinder extension direction) in order to extend the cylinder device, the hydraulic pump 7 discharges the hydraulic fluid from the extension port 7b. Introduced into the first chamber 8g of the cylinder control valve 8 from the passage 4c. In FIG. 10, the check valve 8a is pushed open to open one cylinder chamber A of the cylinder.
Then, the cylinder flows into the passages 4p and 4g communicating with the cylinder to extend the cylinder (this operation is the same as that in FIG. 8).

In order to contract the cylinder device from the extended state, the electric motor 5 is moved in the other direction (cylinder contraction direction).
, The hydraulic fluid is sucked from the extending port 7b of the hydraulic pump 7 and discharged from the contracting port 7c to increase the hydraulic pressure in the passage 4d. The pressure increase in the passage 4d causes the pilot plug 8e of the cylinder control valve 8 to be pushed upward in FIG. 10 to open the check valve 8a, and one cylinder chamber A of the cylinder is contracted by a load or the like, and the hydraulic fluid is released. The cylinder is contracted by being discharged to the reservoir 6 via the passages 4g, 4p, 4c, the hydraulic pump 7, and the relief valve 9f. The contraction speed in this case is proportional to the rotation speed of the hydraulic pump 7.

FIG. 8 shows the cylinder control valve.
The pilot check valve 8c disposed at the intersection of the first passage 4p and the second valve 8s of the cylinder control valve 8 is removed while leaving the pilot spool 8f,
Instead, the second valve 8s is closed from the first passage 4p side by a plug 8n or the like, and the hydraulic pressure in the second chamber 8j in the second valve 8s is drained by the first valve 8r (this port is closed). 3) By making a change to be introduced through the passage 4t to the chamber 8h in which the opening 4e is open, it can be carried out by making only a slight change to the passage structure of the block member 4 in FIGS. Easy to change.

Needless to say, the hydraulic pressure from the other port 7c of the hydraulic pump 7 is supplied from the portion where the drain port of the first valve 8r was provided from the beginning without being closed by the plugs 8f and 8n. If the second valve 8s itself does not need to be machined, the configuration of the cylinder control valve 8 can be further simplified.

In this embodiment, the speed of the cylinder in both directions of expansion and contraction can be variably controlled according to the rotation speed or the discharge flow rate of the hydraulic pump.

In the above embodiments, the case where the inner tube 2 functioning as a piston rod expands and contracts upward from the cylinder tube 1 has been described, but the case where the inner tube 2 expands and contracts horizontally from the cylinder tube 1 is described. In the case where the suction pipe expands or contracts downward, the present invention can be applied by changing the position of the end of the suction pipe in the reservoir tank.

Further, in the above embodiment, it is not specified which one of the cylinder tube and the inner tube is fixed and which one expands and contracts. However, the present invention can be applied to any case.

It is apparent that the present invention is not limited to the above-described embodiment, and that various modifications can be made within the scope of the technical concept.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cylinder device showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a piping configuration of the cylinder device.

FIG. 3 is a sectional view taken along line III-III of FIG. 1, showing the configuration of the cylinder control valve.

FIG. 4 shows the arrangement of a suction control valve.
IV-IV line view of FIG.

FIG. 5 is a sectional view taken along line VV of FIG. 4 showing the other valve configuration.

FIG. 6 is a hydraulic circuit diagram of the cylinder device shown in FIGS. 1 to 5;

FIG. 7 is a cross-sectional view showing another embodiment.

FIG. 8 is a sectional view taken along line VIII-VIII of FIG. 7, illustrating a configuration of a cylinder control valve according to another embodiment.

FIG. 9 is a hydraulic circuit diagram of the cylinder device shown in FIGS. 7 and 8;

FIG. 10 is a sectional view showing a configuration of a cylinder control valve according to still another embodiment.

FIG. 11 is a hydraulic circuit diagram of a cylinder device shown in still another embodiment.

[Explanation of symbols]

A One cylinder chamber B The other cylinder chamber 1 Cylinder tube 2 Inner tube 3 Piston 4 Block member 4c, 4d, 4e, 4f, 4g, 4h, 4p, 4q Passage 4i, 4j Pipe passage 4r, 4s Side hole 5 Electric motor 6 Reservoir tank 7 Hydraulic pump 7b Extension port 7c Contraction port 8 Cylinder control valve 8a, 8b, 8c, 8d Check valve 8e, 8f Pilot plug 8g, 8h, 8i, 8j Chamber 8k, 8m, 8n Plug 8p, 8q Pilot Check valve 8r First valve 8s Second valve 9 Suction valve 9a, 9b Suction check valve 9e, 9f Relief valve 10 Cylinder

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Seiichi Nagata 2-4-1 Hamamatsucho, Minato-ku, Tokyo World Trade Center Building Kayaba Industry Co., Ltd. F-term (reference) 3H081 AA03 BB02 CC23 DD02 DD22 FF47 HH10

Claims (6)

[Claims] 1. A cylinder device for expanding and contracting a cylinder by supplying and discharging hydraulic fluid from a reservoir tank to a cylinder chamber by a hydraulic pump driven by an electric motor, comprising a hollow inner tube and a piston fixed to the inner tube. A cylinder chamber is formed on at least one side of the piston by being slidably housed in the cylinder tube, and the inner tube is divided into two chambers by a block member provided in a middle portion of the inner tube, and one of the chambers is formed. An electric motor is disposed, and the other chamber is a reservoir tank storing working fluid, a hydraulic pump driven by the electric motor in the block member, a suction valve interposed between the hydraulic pump and the reservoir tank, and a hydraulic pressure. A cylinder control valve interposed between the pump and the cylinder chamber. Sunda apparatus. 2. The reservoir tank is disposed in a chamber to which a piston in an inner tube partitioned by the block member is fixed, and the electric motor is disposed in another chamber in the inner tube partitioned by the block member. The cylinder device according to claim 1, wherein the cylinder device is arranged. 3. The cylinder device according to claim 1, wherein the cylinder control valve and the cylinder chamber are communicated with each other through a reservoir passage through a pipe passage disposed between the block member and the piston. 4. The hydraulic pump according to claim 1, wherein the cylinder control valve is disposed between the first and second passages, the first and second passages being substantially parallel to each other, and one port of the hydraulic pump. A check valve for communicating the first chamber to the first passage by the pressure of the first chamber and the first chamber, and a pilot for opening the second passage to the drain port by the pressure of the first chamber. The first one in which a check valve is arranged in series
And a second chamber disposed between the first and second passages and communicating with the other port of the hydraulic pump, and the second chamber is connected to the second passage by the pressure of the second chamber. A second check valve comprising a check valve for communicating with a pilot check valve for opening a first passage to a drain port by the pressure of the second chamber in series, and
The cylinder device according to any one of claims 1 to 3, wherein the cylinder device comprises: 5. A first passage communicating with one of the cylinder chambers and a first chamber disposed adjacent to the first passage and communicating with one port of the hydraulic pump. And a first valve comprising a check valve for communicating the first chamber to the first passage by the pressure of the first chamber; and a first valve arranged adjacent to the first passage and connected to the other port of the hydraulic pump. 2. The apparatus according to claim 1, wherein said second chamber is connected to said second chamber and said second valve is a pilot check valve that opens said first passage to a drain port by a pressure in said second chamber. Item 4. The cylinder device according to any one of items 3. 6. A first passage communicating with one of the cylinder chambers and a first chamber disposed adjacent to the first passage and communicating with one port of the hydraulic pump. A check valve for communicating the first chamber with the first passage by the pressure of the first chamber; and a second valve disposed adjacent to the first chamber and communicating with the other port of the hydraulic pump. 4. The air conditioner according to claim 1, further comprising a chamber, and a pilot spool disposed between the first and second chambers to open the check valve by the pressure of the second chamber. A cylinder device according to one of the preceding claims.