JP2004245340A - Cylinder device with fluid storage tank and pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder device with a fluid storage tank and a pump which leads to no increase in parts count of a tank, and requires no precision in a tank and no restriction in a mounting direction of a tank. <P>SOLUTION: The cylinder device is equipped with a fluid pressure pump 1, with a cylinder 2 in which a cylinder part 24 is included, a first inflow/outflow port 5 is connected to one end side in the cylinder part 24 through a first passage 25 and a second inflow/outflow port 6 is connected to the other end side in the cylinder part 24 through a second passage 26, with a valve device 3 in which valves are respectively interposed between the first passage 25 and a third passage 33 and between the second passage 26 and the third passage 33, and a valve of the passage under the pressurized state is closed and the other is opened when a fluid in the first passage 25 or the second passage 26 is under a pressurized state, and with a tank 4 which communicates to the third passage 33 to accommodate an excessive fluid circulated and discharged from the inside of the cylinder part 24. The tank 4 has an elastic body 40 which varies the volume by receiving the fluid pressure. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cylinder device with a pump such as a small cylinder device with a hydraulic pump.
[0002]
[Prior art]
A conventional cylinder device with a pump of this type has a fluid pressure pump 200 driven by a motor (not shown) as shown in FIGS. 18 and 19 and a piston 204 attached to the tip of a piston rod 203. The cylinder 201 includes a cylinder portion 205 in which a piston 204 is inserted, and a tank 202 that stores fluid.
[0003]
By rotating the motor, the pressurized fluid is pumped to the cylinder device 201 from the first outlet / inlet of the fluid pressure pump 200 to push the piston 204 in one direction, and the piston 204 in the cylinder unit 205 moves. The extruded fluid returns to the fluid pressure pump 200 from the second outlet through the tank 202. When the rotation direction of the motor is reversed, when pressurized fluid is pumped from the second outlet / inlet of the fluid pressure pump 200 to the cylinder 201, the piston 204 is driven in the opposite direction, and at the same time, the fluid pushed out by the piston 204 is stored in the tank. It returns to the fluid pressure pump 200 from the first outlet through 202.
[0004]
In this case, the piston rod that has entered the cylinder portion 205 is the inner volume of the cylinder portion 205 when the piston 204 moves to one end side of the cylinder portion 205 and the inner volume of the cylinder portion 205 when moved to the other end side. There is a difference of 203 volumes. The amount of oil corresponding to this difference changes in the tank 202.
[0005]
In order to absorb the volume difference of the cylinder portion 205 due to the reciprocating motion of the piston 204 of the cylinder device 201, the conventional tank 202 is provided with an air breather 206 to suck and discharge air in the tank 202.
[0006]
However, this conventional tank has a problem in that the mounting direction is restricted and the method of use is limited in order to prevent oil leakage.
[0007]
On the other hand, the tank 202 in FIG. 20 incorporates a spring 207 and a piston 209 with an O-ring 208 in the tank 202 to absorb the change in the oil amount.
[0008]
Furthermore, there is a type in which a flexible bag body is provided in an oil amount adjustment chamber communicating with an oil tank of a hydraulic actuator, and the change in the oil amount in the oil tank is adjusted by expansion / contraction of the flexible bag body. In order to prevent the inner surfaces from adhering to each other when the flexible bag shrinks and is crushed, an elastic member in the form of a round bar is provided inside, so that the flexible bag can be used even if it has been crushed for a long time. Can be easily restored (see Patent Document).
[0009]
[Patent Literature]
JP-A-9-317905
[Problems to be solved by the invention]
The tank 202 in FIG. 20 has no restriction on the mounting direction and the usage method is not limited as compared with the tank in FIG. 19, but the O-ring 208 is in sliding contact with each other, so that the finishing accuracy of the tank inner diameter is required, and the spring 207, There was a drawback that the number of parts such as the piston 209 increased and the price increased.
[0011]
Further, the oil amount adjustment chamber of the patent document requires a flexible bag and an elastic member, and has a drawback that the number of parts increases.
[0012]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a fluid reservoir tank and a cylinder device with a pump that do not increase the number of parts, do not require accuracy in the tank, and have no restriction on the tank mounting direction.
[0013]
[Means for Solving the Problems]
The fluid reservoir tank according to claim 1 is a fluid reservoir tank that contains a fluid, and is provided with an elastic body that changes its volume so as to absorb a change in the fluid amount of the fluid.
[0014]
According to the fluid reservoir tank of the first aspect, since the elastic body absorbs the fluid fluctuation due to the volume change, the number of parts of the tank does not increase, the accuracy in the tank is not required, and the tank is attached. The direction is not regulated. Therefore, when applied to a cylinder device with a pump, the mounting posture is not restricted, and the weight can be reduced and the cost can be reduced.
[0015]
The cylinder device with a pump according to claim 2 has a fluid pressure pump that flows in fluid and pumps pressurized fluid, and a piston that is alternately driven in two directions by the pressurized fluid. A cylinder that discharges fluid returning to the fluid pressure pump with each operation; and a tank that receives a part of the fluid that returns to the fluid pressure pump by each operation of the piston. An elastic body that changes in volume so as to absorb the difference in the amount of fluid in the tank when it moves in one direction and when it moves in the other direction is provided.
[0016]
According to the cylinder device with a pump according to the second aspect, the same effect as the first aspect can be obtained.
[0017]
The cylinder device with a pump according to claim 3, wherein the fluid pressure pump has a first outflow inlet and a second outflow inlet, and inflows fluid from one of them and pumps it from the other.
A piston provided at one end of the piston rod, having a cylinder portion in which the piston is slidably inserted, and the first outflow through the first passage on one end side in the cylinder portion partitioned by the piston; A cylinder to which an inlet is connected, the second outflow inlet is connected to the other end side of the cylinder portion through a second passage, and the piston is driven by the pressure of the fluid;
A first valve interposed between the first passage and the third passage; a second valve interposed between the second passage and the third passage; A valve device in which when the fluid in the passage or the second passage is in a pressurized state, one of the first valve or the second valve in the pressurized state is closed and the other is opened;
A tank for storing excess fluid that communicates with the third passage and is recirculated and discharged by the operation of the piston from within the cylinder portion;
The tank has an elastic body that changes its volume under the pressure of a fluid.
[0018]
According to the cylinder device with a pump according to claim 3, the same effect as in claim 1 is obtained.
[0019]
The cylinder device with a pump according to claim 4 is the cylinder device with a pump according to claim 3, wherein the fluid pressure pump is a swash plate type pump that rotates forward and backward by a motor, and the first outflow inlet or the second outflow is switched by switching the rotation direction of the motor. A pressurized fluid is selectively pumped from the inlet.
[0020]
According to the cylinder device with a pump of a 4th aspect, there exists an effect similar to the 3rd aspect.
[0021]
The cylinder device with a pump according to claim 5 is the cylinder device according to claim 3, wherein the valve device is closed by the pressure when the fluid in the first passage or the second passage is in a pressurized state, and the first device The valve and the second valve are connected to each other so as to open and close relatively.
[0022]
According to the cylinder device with a pump of the fifth aspect, in addition to the same effect as the third aspect, the valve can be switched reliably and the configuration can be simplified.
[0023]
The cylinder device with a pump according to claim 6 is the cylinder device according to claim 3, wherein the elastic body is a foamed material of closed cells.
[0024]
According to the cylinder device with a pump of the sixth aspect, there is the same effect as the third aspect.
[0025]
According to a seventh aspect of the present invention, in the cylinder device with a pump according to the first, second, third, or fourth aspect, the elastic body has a flat plate shape and is substantially C-shaped along the inner peripheral surface of the tank. And a pipe which is disposed in the tank and is disposed at the center of the substantially C-shape of the elastic body and has a flow hole through which a fluid passes is formed on the peripheral surface, and the base end of the pipe is It is connected to 3 passages.
[0026]
According to the cylinder device with a pump according to the seventh aspect, in addition to the same effect as the first, second, third, or fourth aspect, a large volume change is obtained by a slight shrinkage in the radial direction. It is done. In addition, the elastic body can be easily manufactured.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention is shown in FIGS. That is, this small cylinder device with a hydraulic pump has a fluid pressure pump 1, a cylinder 2, a valve device 3, and a tank 4.
[0028]
The fluid pressure pump 1 has a first outflow inlet 5 and a second outflow inlet 6, and inflows fluid from one of them and pumps it from the other. This fluid pressure pump is a swash plate type pump that rotates forward and backward by a motor (not shown), and selectively pumps fluid from the first outlet 5 or the second outlet 6 by switching the rotation direction of the motor. To do. FIG. 1 shows a case where the pump shaft 7 connected to the motor rotates in the clockwise direction of the arrow. For example, oil is used as the fluid.
[0029]
In the embodiment, as shown in FIG. 2, 8 is a case, 9 and 10 are bearings of the pump shaft 7, 11 is a plurality of cylinders integrally provided around the pump shaft 7, and 12 is in the cylinder 11 group. The inserted piston is urged to protrude from one end of the cylinder 11 by a spring 17. Reference numeral 13 denotes a swash plate disposed at the tip of the piston 12. The swash plate 13 has a through-hole 14 through which the pump shaft 7 passes. One end of the swash plate is connected to a shaft 18 perpendicular to the pump shaft 7. Reference numeral 15 denotes a movable support that elastically supports the swash plate 13 with respect to the cylinder 11 at a predetermined inclination angle and a substantially vertical posture. In FIGS. 1 and 2, the swash plate 13 is supported at a predetermined inclination angle. . Each tip of the piston 12 is in sliding contact with the swash plate 13 via a shoe 16. The side of the cylinder 11 opposite to the protruding direction of the piston 12 is connected to a valve plate 19 that is slidably contacted with the lid portion 20 of the case 8, and a communication hole (not shown) is formed in the valve plate 19. A pair of arc-shaped grooves of the same radius having the same center of curvature arranged symmetrically so as to communicate with the communication hole are formed on the surface of the lid portion 20 with which the valve plate 19 is slidably contacted, and a first groove is formed in one of these grooves. One outflow inlet 5 communicates with the other, and the second outflow inlet 6 communicates with the other.
[0030]
Accordingly, the pair of grooves communicate with the cylinder 11 group when the piston 12 ascends the swash plate 13 and the cylinder 11 group when the piston 12 descends the swash plate 13 in one rotation of the pump shaft 7. In the case of FIG. 1, the 1st outflow port 5 becomes a discharge port which flows out as pressurized fluid, and the 2nd outflow port 6 becomes a suction port into which a fluid flows in (refer FIG.8 (c)). Here, FIG. 8C is a cross-sectional view of the fluid pressure pump. When the pump shaft 7 is rotated in the reverse direction to the above, the first outflow inlet 5 becomes the inflow of the added fluid, and the second outflow inlet 6 becomes the outflow of the pressurized fluid. Further, when the swash plate 13 is pushed by the spring 17 due to the retreat of the support 15 to change from a tilted posture at a predetermined angle to a substantially vertical posture, the pumping amount of the pressurized fluid is reduced and the piston 23 is held at a constant pressure. do.
[0031]
The cylinder 2 reciprocates the piston by the pressurized fluid pumped from the fluid pressure pump 1. This cylinder 2 has a piston 23 provided at one end portion of a piston rod 22, a cylinder portion 24 in which the piston 23 is slidably inserted, and a first end side of the cylinder portion 24 partitioned by the piston 23. The first outlet 5 is connected through the first passage 25, the second outlet 6 is connected through the second passage 26 to the other end of the cylinder portion 24, and the piston 23 is driven by the pressure of the fluid. In the embodiment, 28 is a penetrating portion for penetrating the other end of the piston rod 22 in a liquid-tight manner, 29 is one cylinder chamber communicating with the first passage 25 partitioned by the piston 23 in the cylinder portion 24, and 30 is The other cylinder chamber communicates with the second passage 26. The first passage 25 communicates with a passage (drain port) 25a of a coupling body (manifold block) 27 that connects the cylinder portion 24 (FIG. 8A), and communicates with the first outlet 5 through the passage 25a. Here, FIG. 8A is a cross-sectional view taken along line BB in FIG. The second passage 26 is a side passage formed in the axial direction of the cylinder portion 24 within the wall thickness of the cylinder portion 24, further communicates with the passage 26a of the coupling body 27, and passes through the passage (drain port) 26a to form the second outlet / inlet. 6 communicates. Reference numeral 55 (FIG. 4) denotes a connecting bolt as connecting means.
[0032]
The valve device 3 includes a first valve 32 interposed between the first passage 25 and the third passage 33, and a second valve interposed between the second passage 26 and the third passage. It has a valve 34. When the fluid in the first passage 25 or the second passage 26 is in a pressure state, one of the first valve 32 and the second valve 34 in the pressure state is closed and the other is opened. It is configured. That is, the valves 32 and 34 of the valve device 3 are check valves that are arranged so as to face each other and are energized by a spring 35 to close, and the first valve 32 and the second valve 34 are The connecting portions 36 are connected to each other so as to open and close relatively. Therefore, when the fluid in the first passage 25 is in a pressurized state, the first valve 32 is closed by the pressure, and thereby the second valve 34 is opened. Further, when the fluid in the second passage 26 is in a pressurized state, the second valve 34 is closed by the pressure, and thereby the first valve 32 is opened.
[0033]
In the embodiment, the fluid pressure pump 1 is connected to the connecting body 27 so as to be parallel to the same side as the cylinder 2, and the first outlet 5 of the fluid pressure pump 1 communicates with the passage 25a as described above. The two outflow inlets 6 communicate with the passage 26a (FIG. 8A). As a result, in FIG. 1, the first valve 32 of the valve device is closed by the pressurized fluid discharged from the first outlet 5, and is pushed by the first valve 32 via the connecting portion 36. The valve opens. Thereby, the pressurized fluid flows into the one cylinder chamber 29 from the first passage 25 without flowing into the third passage 33 and starts to push the piston 23. The fluid in the other cylinder chamber 30 is pushed by the piston 23 by the operation of the piston 23 and flows into the third passage 33 from the second passage 26 through the passage 26a through the second outlet 6 and the valve 34. Reference numeral 45 denotes an opening for fluid removal or fluid filling that communicates with the third passage 33.
[0034]
The tank 4 is a fluid reservoir tank that contains a fluid, and includes an elastic body 40 that changes in volume so as to absorb fluctuations in the amount of fluid. In the embodiment, the tank 4 accommodates the fluid recirculated from the cylinder 2 to the fluid pressure pump 1 by the operation of the piston 23, and communicates with the third passage 33 through the valve device 3 from the inside of the cylinder 2 to the piston. The excess fluid discharged | emitted by the operation | movement of 23 is accommodated. In this case, the cylinder chambers 29 and 30 become maximum when the piston 23 moves in one direction or the other direction, but the maximum volume of the cylinder chamber 30 is larger than the maximum volume of the cylinder chamber 29 by the volume of the piston rod 22. Is also getting smaller. For this reason, when the piston 23 moves in one direction and when it moves in the other direction, the amount of fluid accumulated in the tank 4 varies by the volume of the piston rod 22. At this time, the elastic body 40 changes its volume so as to absorb the fluctuation of the fluid. For example, the elastic body uses a foamed material of closed cells, for example, a sponge using urethane or neoprene rubber.
[0035]
In the embodiment, the elastic body 40 has a flat plate shape and is deformed into a substantially C shape along the inner peripheral surface of the tank 4 and is stored in the tank 4. On the other hand, the pipe 43 is disposed at the center of the substantially C-shape of the elastic body 40 (FIG. 8B), and the base end portion of the pipe 43 is connected to the third passage 33. The pipe 43 is formed with a circulation hole 44 through which a fluid passes on the peripheral surface. Here, FIG.8 (b) is the sectional view on the AA line of FIG.
[0036]
In the embodiment, the tank 4 has a cylindrical shape, and is attached to the opposite side of the connecting body 27 from the cylinder 2 and the fluid pressure pump 1. In this case, a check valve 50 biased by a spring is provided at the inlet of the tank 4, and a check valve 51 biased by a spring is also provided in the third passage 33 of the connecting body 27. In the separated state of the connecting body 27, it is closed so that oil does not spill. By connecting the tank 4 to the connecting body 27, the check valves 50 and 51 are pressed against each other to open, and the third passage 33 and the inlet 52 are communicated. In FIG. 1, since the piston 23 is located up to a position where the volume of the cylinder chamber 29 where the piston rod 22 is not located is the minimum, the amount of fluid in the tank 4 is the maximum, and the elastic body 40 is caused by the pressure. The pipe 43 is compressed so that it is spread radially outward from the periphery of the pipe 43 and pressed against the peripheral surface of the tank 4. The elastic body 40 is set to be compressed by about 25%. 41 is a plug for closing the end of the tank 4, 56 is a connecting bolt as connecting means, and 57 is a screw hole (FIG. 4) provided in the connecting body 27.
[0037]
FIG. 1 and FIG. 8 show a state where the fluid is started to be pressed into the cylinder chamber 29 by rotating the motor clockwise.
[0038]
5 and 9 show a state where the piston 23 is pressed by the fluid from the state shown in FIG. At this time, the cylinder chamber 29 becomes the maximum and the cylinder chamber 30 becomes the minimum, but since the piston rod 22 is not in the cylinder chamber 29, the fluid enters the cylinder 2 most. That is, the fluid discharged from the first outlet 5 of the fluid pressure pump 1 flows through the passage 25a and the first passage 25 and enters the cylinder chamber 29, pushes the piston 23, and the cylinder chamber 30 pushed by the piston 23. Of the fluid passes through the second passage 26 and the passage 26a and is sucked into the cylinder 11 in the suction process of the fluid pressure pump 1 from the second outlet 6 and the cylinder chambers 29 and 30 become substantially the same volume by the movement of the piston 23. When the position is exceeded, the shortage flows from the tank 4. As a result, the elastic body 40 is restored in the tank 4 and the volume is increased to the state shown in FIGS. 5 and 9B. When the piston 23 is positioned on the opposite side of the cylinder portion 24, the piston 23 stops, but the motor rotates in the same direction. Therefore, the inclination angle of the swash plate 13 is set to a substantially vertical posture in order to keep the fluid pressure constant. I have to. As a result, the piston rod 22 protrudes from the cylinder 2 and is maintained in a state where it protrudes due to fluid pressure.
[0039]
6 and 10 show a state in which the motor is stopped from the state of FIG. 5 and the swash plate 13 is returned to the original inclination angle to reversely rotate the motor, that is, rotate counterclockwise. At this time, the fluid pressure pump 11 has the second outlet 6 as a discharge port and the first outlet 5 as a suction port. Accordingly, since the passage 26a communicating with the second outflow inlet 6 is in a pressurized state, the valve 34 is pressed and closed, and the passage 25a connected to the first outflow inlet 5 is on the suction side, so that the valve 32 is opened and the passage 26a. Then, it flows into the cylinder chamber 30 through the second passage 26 and drives the piston 23 in the opposite direction. As a result, the fluid discharged from the cylinder chamber 29 passes through the passage 25 through the passage 25 a and is sucked into the cylinder 11 in the suction process of the fluid pressure pump 1 from the first outlet 5 and the excess is passed through the valve 32. And start to accumulate in the tank 4.
[0040]
7 and 11 show a state in which the piston 23 enters the cylinder portion 24 in FIG. 6, the cylinder chamber 29 partitioned by the piston 23 is minimum and the cylinder chamber 30 is maximum, and the swash plate 13 This is a state where the piston 23 is held at a constant pressure by continuing the rotation of the motor with the inclination substantially vertical. Further, as described above, surplus fluid corresponding to the difference between the maximum volume of the cylinder chamber 30 and the maximum volume of the cylinder chamber 29 accumulates in the tank 4, and the elastic body 40 is expanded inside by the pressure of the piston 23. 4 is compressed against the inner peripheral surface. Thereafter, when the swash plate 13 is tilted and the motor is stopped and rotated in the reverse direction, the state shown in FIG. 1 is obtained.
[0041]
The support 15 is moved by the control means, but the movement from the tilted position of the swash plate 13 to the substantially vertical position can be performed by detecting the vicinity of the end of the two-way movement of the piston 23. When starting up, it can be made to move to an inclined posture.
[0042]
A second embodiment of the present invention is shown in FIGS. That is, in the first embodiment, the tank 4 is cylindrical, the elastic body 40 is a columnar sponge, and the length is about a little less than half the internal volume of the tank 4. Is stored in the tank 4 and the pipe 43 is omitted. In this case, the excess fluid is compressed in the axial direction of the tank 4. In addition, 58 is a connecting bolt that is a connecting means of the fluid pressure pump 1, and 59 is an assembly screw for the fluid pressure pump 1.
[0043]
A third embodiment of the present invention is shown in FIG. That is, in the second embodiment, a belt-like sponge is wound around the elastic body 40 in a spiral manner and stored in the tank 4. In this case, the elastic body 40 is compressed in the thickness direction and the width direction by the surplus fluid in the axial direction and the circumferential direction of the tank 4. The elastic body of this embodiment can also be easily manufactured as in the first embodiment.
[0044]
A fourth embodiment of the present invention is shown in FIGS. That is, in the first embodiment, the tank 4 uses the conventional tank 202 and houses the elastic body 40 similar to that of the second embodiment inside. Since the inside of the tank 4 is sealed by the elastic body 40, even if there is an air breather 206, it is not affected by the mounting posture or the like.
[0045]
【The invention's effect】
According to the fluid reservoir tank of the first aspect, since the elastic body absorbs the fluid fluctuation due to the volume change, the number of parts of the tank does not increase, the accuracy in the tank is not required, and the tank is attached. The direction is not regulated. Therefore, when applied to a cylinder device with a pump, the mounting posture is not restricted, and the weight can be reduced and the cost can be reduced.
[0046]
According to the cylinder device with a pump of Claim 2 and Claim 3, there exists an effect similar to Claim 1.
[0047]
According to the cylinder device with a pump according to claim 4 and claim 6, the same effect as in claim 3 is obtained.
[0048]
According to the cylinder device with a pump of the fifth aspect, in addition to the same effect as the third aspect, the valve can be switched reliably and the configuration can be simplified.
[0049]
According to the cylinder device with a pump according to the seventh aspect, in addition to the same effect as the first, second, third, or fourth aspect, a large volume change is obtained by a slight shrinkage in the radial direction. It is done.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a piston according to a first embodiment of the present invention starting from a retracted state to an advanced state.
FIG. 2 is a cross-sectional view of the fluid pressure pump.
FIG. 3 is a cross-sectional view of a cylinder device.
4A is a cross-sectional view of a connection body and a tank in a separated state, and FIG. 4B is a cross-sectional view illustrating a connection structure of the connection body.
FIG. 5 is a cross-sectional view of a piston in an advanced state.
FIG. 6 is a cross-sectional view when starting to move backward from the advanced state of the piston.
FIG. 7 is a sectional view of a piston in a retracted state.
8 corresponds to FIG. 1, (a) is a sectional view taken along line BB in FIG. 1, (b) is a sectional view taken along line AA in FIG. 1, and (c) is a sectional view showing a discharge port and a suction port of a fluid pressure pump. FIG.
9 corresponds to FIG. 5, (a) is a cross-sectional view at the same position as FIG. 8, and (b) is a cross-sectional view at the same position as FIG.
10 corresponds to FIG. 6, (a) is a cross-sectional view at the same position as FIG. 8, (b) is a cross-sectional view at the same position as FIG. 8, and (c) is a discharge port and a suction port of the fluid pressure pump. It is sectional drawing shown.
11 corresponds to FIG. 7, (a) is a cross-sectional view at the same position as FIG. 8, (b) is a cross-sectional view at the same position as FIG. 8, and (c) is a discharge port and a suction port of the fluid pressure pump. It is sectional drawing shown.
FIG. 12 is a side view showing a cross section of the tank.
FIG. 13 is a side view showing a section of a tank according to the second embodiment.
14A and 14B show a tank, wherein FIG. 14A is a transverse sectional view thereof, and FIG. 14B is a longitudinal sectional view thereof.
FIG. 15 is a cross-sectional view showing a sponge in a tank according to a third embodiment.
FIG. 16 is a side view showing a cross section of a tank according to a fourth embodiment.
FIG. 17 is a side view showing a cross section of the tank in a compressed state of the sponge.
FIG. 18 is a schematic cross-sectional view of a conventional example.
FIG. 19 is an enlarged sectional view of the tank.
FIG. 20 is a cross-sectional view of another conventional tank.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fluid pressure pump 2 Cylinder 3 Valve apparatus 4 Tank 5 1st outflow inlet 6 2nd outflow inlet 7 Pump shaft 11 Cylinder 12 Piston 13 Swash plate 14 Through-hole 15 Support body 16 Shoe 17 Spring 18 Shaft 19 Valve plate 20 Piston rod 23 Piston 24 Cylinder part 25 1st channel | path 26 2nd channel | path 27 Connection body 29 Cylinder chamber 30 Cylinder chamber 32 1st valve 33 3rd channel | path 34 2nd valve 40 Elastic body 43 Pipe 44 Flowing hole

Claims (7)

A fluid reservoir tank that contains a fluid, and is provided with an elastic body that changes in volume so as to absorb fluctuations in the fluid amount of the fluid. A fluid pressure pump that flows in fluid and pumps pressurized fluid, and a piston that is alternately driven in two directions by the pressurized fluid, and returns to the fluid pressure pump with each operation of the piston in the two directions. A cylinder for discharging the fluid to be discharged, and a tank for receiving a part of the fluid that is returned to the fluid pressure pump by each operation of the piston, and the tank moves in the other direction when the piston moves in one direction. A cylinder device with a pump, characterized in that an elastic body whose volume changes so as to absorb the difference in the amount of fluid in the tank when moved is incorporated. A fluid pressure pump having a first outflow inlet and a second outflow inlet for injecting fluid from one of them and pumping it from the other;
A piston provided at one end of the piston rod, having a cylinder portion in which the piston is slidably inserted, and the first outflow through the first passage on one end side in the cylinder portion partitioned by the piston; A cylinder to which an inlet is connected, the second outflow inlet is connected to the other end side of the cylinder portion through a second passage, and the piston is driven by the pressure of the fluid;
A first valve interposed between the first passage and the third passage; a second valve interposed between the second passage and the third passage; A valve device in which when the fluid in the passage or the second passage is in a pressurized state, one of the first valve or the second valve in the pressurized state is closed and the other is opened;
A tank for storing excess fluid that communicates with the third passage and is recirculated and discharged by the operation of the piston from within the cylinder portion;
The cylinder device with a pump, wherein the tank has an elastic body that changes its volume under the pressure of a fluid. 4. The fluid pressure pump according to claim 3, wherein the fluid pressure pump is a swash plate type pump that is rotated forward and backward by a motor, and the pressurized fluid is selectively pumped from the first outlet or the second outlet by switching the rotation direction of the motor. Cylinder device with pump. The valve device is closed by the pressure when the fluid in the first passage or the second passage is pressurized, and the first valve and the second valve are opened and closed relative to each other. The cylinder apparatus with a pump of Claim 3 connected with this. The cylinder device with a pump according to claim 3, wherein the elastic body is a closed cell foam. The elastic body has a flat plate shape, is deformed into a substantially C shape along the inner peripheral surface of the tank and is accommodated in the tank, and is disposed at the center of the substantially C shape of the elastic body so that fluid passes therethrough. The cylinder device with a pump according to claim 1, 2, 3, or 4, wherein a pipe in which a circulation hole is formed on a peripheral surface is disposed, and a base end portion of the pipe is connected to the third passage.

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