JP2013139832A - Cylinder device and throwing device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder device that continuously impart large force to an object, and can control the force imparted to the object.SOLUTION: A first opening 32 and a second opening 34 are arranged in a bottom part of a cylinder tube 12. A first valve 24 is arranged in a passage for injecting gas into a tank 20. A second valve 26 is arranged in a passage for injecting the gas into an inside space 18 of the cylinder tube 12 via the second opening 34. A magnet 22 is arranged on a bottom surface of the cylinder tube 12, and attracts a piston 14 to the bottom surface side of the cylinder tube 12. In a state of attracting the piston 14 to a bottom surface of the cylinder tube 12 by the magnet 22, a space formed of a pressure receiving surface 16 of the piston 14 and an inner wall of the cylinder tube 12, is partitioned into a first space 18a communicating with the tank 20 via the first opening 32 and a second space 18b communicating with the second valve 26 via the second opening 34.

Description

  The present invention relates to a cylinder device.

  As an object throwing device, one using a pneumatic cylinder is known. FIG. 1 is a diagram showing a configuration of a anchoring device using a pneumatic cylinder examined by the present inventors. The anchoring device 4r includes a pneumatic cylinder 10r, a tank 20r, and a valve 21r. Air compressed with a certain pressure is sealed in the tank 20r. The pneumatic cylinder 10r includes a cylinder tube 12r and a piston 14r. The piston 14r is provided in the cylinder tube 12 so as to be slidable in the axial direction. An internal space 18r formed by the pressure receiving surface 16 of the piston 14r and the inner wall of the pneumatic cylinder 10r communicates with the tank 20r via a valve 21r. An object 6r to be thrown is mounted on the tip 30 of the rod 28 connected to the piston 14r.

  Air is supplied into the tank 20r with the valve 21r closed (shut off). After the pressure in the tank 20 has increased to some extent, when the valve 21r is opened (conduction), the pressure of the gas in the tank 20r acts on the pressure receiving surface of the piston 14r, and the piston 14r is pushed out. As a result, the object 6r is accelerated and thrown.

  In the anchoring device 4r of FIG. 1, when the valve 21r is opened, the pressure in the cylinder rises rapidly, but the piston starts to move before the pressure in the cylinder is still high enough. Therefore, a sufficiently large acceleration cannot be obtained from the time point when the piston starts to move.

  In the anchoring device 4r in FIG. 1, the volume of the internal space 18r increases as the piston 14r slides. In order to throw the object 6r far away, a large pressure must be continuously applied to the pressure receiving surface of the piston 14r. That is, as the volume of the internal space 18r increases, air corresponding to the volume increase amount is stored in the tank. It must continue to be supplied from 20r to the internal space 18r.

  However, in the anchoring device 4r shown in FIG. 1, the amount of air supplied to the internal space 18r is limited by the valve 21r provided between the tank 20r and the internal space 18r. When the supply amount of air from the tank 20r is less than the increase amount of the internal space 18r, the pressure in the internal space 18r, that is, the pressure received by the piston 14r is decreased, and the acceleration is decreased. In other words, in the anchoring device 4r of FIG. 1, the force applied to the object 6r is maximized immediately after opening the valve 21r, and thereafter decreases as the sliding amount of the piston 14r increases.

  This problem can be solved by increasing the size of the valve 21r, but this brings about another problem of increasing the size and cost of the anchoring device 4r as a whole.

  The present invention has been made in view of such a problem, and one of exemplary purposes of an embodiment thereof is capable of continuously applying a large force to an object and controlling the force applied to the object. To provide a cylinder device.

  One embodiment of the present invention relates to a cylinder device. A cylinder device includes a cylinder tube provided with a first opening and a second opening at a bottom thereof, a piston provided in the cylinder tube so as to be capable of reciprocating in an axial direction, a tank for containing gas, a tank A first valve provided in a path for injecting gas into the inside, a second valve provided in a path for injecting gas into the internal space of the cylinder tube through the second opening, and provided on the bottom surface of the cylinder tube, And a magnet that attracts the piston to the bottom surface side of the cylinder tube. In a state where the piston is attracted to the bottom surface of the cylinder tube by the magnet, an internal space formed by the pressure receiving surface of the piston in the cylinder tube and the inner wall of the cylinder tube is a first space communicating with the tank through the first opening; A second space communicating with the second valve through the second opening is partitioned.

In this cylinder device, when the force received by the piston on the pressure receiving surface exceeds the attractive force of the magnet, the piston is released from the magnet, and the piston is accelerated. Then, after the piston is released from the attractive force of the magnet, the first space and the second space become one internal space.
According to this aspect, the piston is attracted by the magnetic force, and the piston does not start unless the pressure is sufficiently increased until the magnetic force is overcome. Therefore, the acceleration becomes a large value from the beginning.
Further, since the first opening communicates with the tank without passing through the valve, the gas is supplied to the internal space without receiving the resistance of the valve. As a result, it is possible to suppress the pressure drop in the internal space caused by the sliding of the piston, and to continuously apply a large force to the object.
Further, the force applied to the object can be controlled by controlling the opening and closing timing of the first valve and the second valve. In the present specification, the “bottom portion” of the cylinder tube refers to a portion in contact with the internal space in a state where the piston is pressed against the bottom surface side, and includes not only the bottom surface of the cylinder but also the side surface.

  The second valve may be provided between the tank and the second opening. Alternatively, the second valve may be provided between the second opening and a pump that supplies gas into the tank via the first valve. Alternatively, the second valve may be provided between the second opening and the first valve.

The cylinder device includes (1) a first mode in which gas is injected into the tank with both the first valve and the second valve opened, and (2) a state in which the first valve is opened and the second valve is closed. It may be possible to switch between the second mode in which gas is injected into the tank and then the second valve is opened.
The pressure receiving area of the piston from the first space is S1, and the pressure receiving area of the piston from the second space is S2. In the first mode, the pressure in the first space and the second space is equal to the pressure P _TANK in the tank, and the force F received by the piston is P _TANK × (S1 + S2). When the pressure P _TANK in the tank increases with time and the force F exceeds the attractive force F _MAG by the magnet, the piston is opened. A pressure (referred to as a first threshold value) P _L in the tank when the piston is opened is given by Equation (1) using the attractive force F _MAG of the magnet.
P _L = F _MAG / (S1 + S2) (1)
That is, in the first mode, a force determined according to the attractive force F _MAG of the magnet can be applied to the object.

In a state where the second valve is closed, the force F received by the piston is P _TANK × S1. The pressure in the tank when the piston is opened in this state (second threshold value P _H ) is given by Expression (2), and P _H > P _L is satisfied.
P _H = F _MAG / S1 (2)
In the second mode, the pressure _{P TANK} in the _tank, opening the second valve when the range of _{P L <P TANK <P H} , the force F 'which at the moment the open piston receives the formula (3) and It becomes larger than the attractive force F _{MAG of} the magnet.
F ′ = P _TANK × (S1 + S2) (3)
Therefore, according to the second mode, it is possible to apply a larger force to the object than in the first mode, and it is possible to adjust the force according to the pressure in the tank at the timing of opening the second valve. .

In addition to the first and second modes, the cylinder device may be switchable between a third mode in which the first valve is opened and gas is continuously injected into the tank with the second valve closed.
In the third mode, the pressure in the tank reaches the threshold P _H of the formula (2), the piston is released.

The magnet may have a ring shape concentric with the piston. The cylinder device may further include an O-ring provided between the magnet and the piston and partitioning the first space and the second space.
In this case, the pressure receiving areas of the first space and the second space can be defined according to the diameter of the O-ring.

  One of the first opening and the second opening may be provided at the center of the bottom surface of the cylinder tube, and the other of the first opening and the second opening may be provided on the outer peripheral side of the bottom surface of the cylinder tube.

  The first opening may be provided in the side surface of the cylinder tube, and the second opening may be provided in the center of the bottom surface of the cylinder tube. By providing the first opening on the side surface, the area can be made larger than when it is provided on the bottom surface, and the flow resistance of the gas supplied to the internal space after the piston is opened can be reduced.

Another aspect of the present invention relates to a anchoring device. The anchoring device includes the cylinder device according to any one of the above-described aspects.
According to this aspect, the object can be thrown by placing the object on the tip of the rod connected to the piston and transmitting the acceleration of the piston to the object. The throwing distance or throwing height can be controlled.

  According to the cylinder device of an aspect of the present invention, a large force can be continuously applied to the object, and the force applied to the object can be controlled.

It is a figure which shows the structure of the anchoring apparatus using the pneumatic cylinder which the present inventors examined. Fig.2 (a) is sectional drawing which shows the structure of the cylinder apparatus based on Embodiment, FIG.2 (b) is the II sectional view taken on the line of the cylinder apparatus of Fig.2 (a). FIGS. 3A and 3B are perspective views of the cylinder tube of FIG. 2 on the bottom side of the pressure receiving surface. 4A to 4D are time waveform diagrams showing the operation of the cylinder device. FIGS. 5A to 5C are diagrams showing a configuration of a cylinder device according to a modification. FIGS. 6A and 6B are diagrams showing the configuration of a cylinder device according to a modification. FIGS. 7A and 7B are views showing a mobile robot using a cylinder device as a throwing device.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

(First embodiment)
FIG. 2A is a cross-sectional view showing the configuration of the cylinder device 100 according to the embodiment, and FIG. 2B is a cross-sectional view taken along the line I-I of the cylinder device 100 of FIG. The cylinder device 100 includes a cylinder tube 12, a piston 14, a tank 20, a magnet 22, a first valve 24, and a second valve 26.

  The piston 14 is provided in the cylindrical cylinder tube 12 so as to be slidable in the axial direction. An internal space 18 (18a, 18b) is formed between the pressure receiving surface 16 of the piston 14 and the inner wall of the cylinder tube 12. A first opening 32 and a second opening 34 are provided at the bottom of the cylinder tube 12. A first adapter 38 and a second adapter 40 are fitted in the first opening 32 and the second opening 34, respectively, and can be connected to external piping.

  The tank 20 is an accumulator that contains gas. The volume of the tank 20 is preferably sufficiently larger than the volume of the cylinder tube 12. The first valve 24 is provided in a path for injecting gas into the tank 20. A pump (not shown) is connected to the first valve 24, and a gas such as air is injected into the tank 20 through the first valve 24. The second valve 26 is provided in a path for injecting gas into the internal space 18 of the cylinder tube 12 through the second opening 34. Specifically, the second valve 26 is provided between the tank 20 and the second opening 34.

  An opening 42 is also provided in the upper part of the cylinder tube 12. It is desirable to add an air cushion mechanism to the opening 42 in order to mitigate the collision of the piston 14 with the end. The air cushion mechanism is a known technique, and the piston 14 itself blocks most of the opening 42 immediately before the end, and the piston speed is rapidly reduced.

  A magnetic body 15 is attached to the piston 14. The magnet 22 is provided on the bottom surface of the cylinder tube 12 and attracts the piston 14 to the bottom surface side of the cylinder tube 12 by a magnetic force acting between the magnet body 15 and the magnet 22. The piston 14 itself may be formed of a magnetic material.

  The magnetic body 15 has a ring shape concentric with the piston 14. The shape of the magnetic body 15 is not particularly limited, and a plurality of magnets 22 may be arranged at the bottom of the cylinder tube 12.

  FIG. 2B shows the pressure receiving surface 16 of the piston 14, and in a state where the piston 14 is attracted to the bottom of the cylinder tube 12, the region S 1 inside the O-ring 36 applies pressure from the first space 18 a. The region S2 outside the O-ring 36 receives pressure from the second space 18b.

  FIGS. 3A and 3B are perspective views of the cylinder tube 12 of FIG. 2 on the bottom side of the pressure receiving surface 16. In the state where the piston 14 is attracted to the bottom surface of the cylinder tube 12 by the magnet 22, the internal space 18 formed by the pressure receiving surface 16 of the piston 14 and the inner wall of the cylinder tube 12 in the cylinder tube 12 is first defined by the O-ring 36. It is partitioned into a space 18a and a second space 18b. The first space 18 a communicates with the tank 20 through the first opening 32, and the second space 18 b communicates with the tank 20 through the second opening 34 and the second valve 26.

  FIG. 3A shows a structure corresponding to FIG. 2A, and the bottom of the cylinder tube 12 has a double cylindrical shape. The inner cylindrical portion 12b enters the inside of the magnet 22, and the O-ring 36 is fitted to the upper portion of the cylindrical portion 12b. That is, the inner space 18 is divided into the first space 18 a and the second space 18 b by the inner cylindrical portion 12 b and the O-ring 36.

  In FIG. 3B, the O-ring 36 is provided on the upper surface of the magnet 22. In this configuration, the cylindrical portion 12b of FIG. 3B is not necessary, and the internal space 18 is partitioned into a first space 18a and a second space 18b by the magnet 22 and the O-ring 36. According to this, in the range of the ring-shaped magnet 22, the diameter of the O-ring 36, that is, the pressure receiving areas S1 and S2 can be changed. In addition to FIGS. 3A and 3B, the first space 18a and the second space 18b can be partitioned by various structures, and these are also included in the scope of the present invention.

The above is the configuration of the cylinder device 100. Next, the operation will be described.
In this cylinder device 100, when the force F received by the piston 14 on the pressure receiving surface 16 exceeds the attractive force F _MAG of the magnet 22, the piston 14 is released from the magnet 22 and the piston 14 is accelerated. After the piston 14 is released from the attractive force F _MAG by the magnet 22, the first space 18 a and the second space 18 b are connected to form one internal space 18.

  Here, since the first opening 32 communicates with the tank 20 without passing through the valve, gas can be supplied to the internal space 18 without receiving resistance of the valve. As a result, it is possible to suppress a decrease in the pressure in the internal space 18 due to the sliding of the piston 14 and to continuously apply a large force to the object.

  Further, the force applied to the object can be controlled by controlling the opening and closing timing of the first valve and the second valve. Specifically, the cylinder device 100 can be operated in any one of the first mode to the third mode. The operation in each mode will be described below.

4A to 4D are time waveform diagrams showing the operation of the cylinder device 100. FIG. 4A shows the internal pressure P _TANK of the tank 20, FIG. 4B shows the states V1 and V2 of the first valve 24 and the second valve 26 in the first mode, and FIG. 4C shows the second pressure. FIG. 4D shows the states V1 and V2 of the first valve 24 and the second valve 26 in the third mode, and FIG. 4D shows the states V1 and V2 of the first valve 24 and the second valve 26 in the mode. In the state V1, the low level indicates a closed state, and the high level indicates an open state.

(First mode)
First, the operation in the first mode will be described with reference to FIGS. 4 (a) and 4 (b). In the first mode, gas is injected into the tank 20 with both the first valve 24 and the second valve 26 open. As a result, as shown in FIG. 4A, the tank internal pressure P _TANK increases with time.

In the first mode, since the second valve 26 is open, the pressure in the first space 18 a and the second space 18 b is equal to the pressure P _TANK in the tank 20. Therefore, the force F received by the piston 14 is P _TANK × (S1 + S2).
When the pressure P _TANK in the tank increases with time and the force F exceeds the attractive force F _MAG by the magnet at time t _L , the piston 14 is opened. Pressure (referred to as a first threshold value) _{P L} in the tank 20 when the piston 14 is opened by using the attractive force _{F MAG} magnet is given by Equation (1).
P _L = F _MAG / (S1 + S2) (1)

That is, in the first mode, a force determined according to the attractive force F _{MAG of the} magnet 22 and the pressure receiving areas S1 and S2 can be applied to the object.

(Third mode)
Although the order is reversed, the third mode will be described with reference to FIGS. 4 (a) and 4 (d).
In the third mode, the gas is continuously injected into the tank 20 with the first valve 24 opened and the second valve 26 closed.
In the state where the second valve 26 is closed, the force F received by the piston 14 is P _TANK × S1. When the force F exceeds the attractive force F _MAG by the magnet at time t _H , the piston 14 is released. The pressure (second threshold value P _H ) in the tank 20 when the piston 14 is opened is given by Expression (2), and P _H > P _L is established.
P _H = F _MAG / S1 (2)

That is, in the third mode, a force determined according to the attractive force F _{MAG of the} magnet 22 and the pressure receiving area S 1 can be applied to the object.

(Second mode)
Subsequently, the operation in the second mode will be described with reference to FIGS. In the second mode, the first valve 24 is opened, the gas is injected into the tank 20 with the second valve 26 closed, and then the second valve 26 is opened at a certain time t1.

In the second mode, the pressure _{P TANK} in the _tank, opening the second valve when the range of _{P L <P TANK <P H} , the force F at the instant the open piston is subjected _{is, F = P TANK} × S1 To a force F ′ given by the equation (3).
F ′ = P _TANK × (S1 + S2) (3)
When P _{L <P} TANK where _{<P H} is satisfied, because the force F 'is greater than the attractive force _{F MAG} magnet 22, the piston 14 immediately after opening the second valve is released from the attraction of the magnet 22.

  Therefore, according to the second mode, it is possible to apply a larger force to the object than in the first mode, and it is possible to adjust the force according to the timing t1 when the second valve 26 is opened.

  The above is the operation of the cylinder device 100. This cylinder device 100 has an advantage that the size of the second valve 26 may be small. This is because in any of the first mode to the third mode, after the piston 14 is opened, the first space 18a and the second space 18b are connected, so the size of the second valve 26 is small, and the second opening 34 This is because a large amount of gas can be supplied through the first opening 32 that is not provided with a valve even when the gas flow rate through the valve is small. From this viewpoint, it is preferable that the first opening 32 has a larger cross-sectional area.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. is there. Hereinafter, such modifications will be described.

FIGS. 5A to 5C are diagrams showing a configuration of a cylinder device according to a modification.
In the cylinder device 100a in FIG. 5A, the first space 18a and the second space 18b are opposite to those in FIG.
In the cylinder device 100 b of FIG. 5B, the first opening 32 is provided on the side surface of the cylinder tube 12. In this case, the area of the 1st opening 32 can be enlarged compared with Fig.5 (a), and the flow resistance of the gas supplied to the internal space 18 after piston opening can be reduced.

As shown in FIG. 5C, part or all of the cylinder tube 12 may be accommodated in the tank 20c. That is, the gas supplied from the first valve 24 is stored in the space 19 between the outer wall of the cylinder tube 12 and the inner wall of the tank 20c. A plurality of first openings 32 are provided on the side surface of the cylinder tube 12, and the first space 18 a and the space 19 are connected via the first opening 32.
According to this configuration, since the area of the first opening 32 can be increased compared to the case where the first opening 32 is provided on the bottom surface of the cylinder tube 12, a large amount of gas is supplied from the tank 20c to the internal space 18 after the piston 14 is opened. Can supply.

Although FIG. 2 and FIG. 5 demonstrated the case where the 2nd valve | bulb 26 was provided between the 2nd opening 34 and the tank 20, this invention is not limited to it. FIGS. 6A and 6B are diagrams showing the configuration of a cylinder device according to a modification. In the cylinder device 100 d of FIG. 6A, the second valve 26 is provided between the second opening 34 and a pump (not shown) that supplies gas into the tank 20. In the cylinder device 100e of FIG. 6B, the second valve 26 is provided between the first valve 24 and the second opening 34.
Since the second valve 26 does not require such a large flow rate, even if gas is supplied to the second valve 26 without passing through the tank 20 as shown in FIGS. The same effect as the cylinder device of FIG. 5 can be obtained. Of course, the modification of FIG. 6 can be combined with any modification of FIG.

Finally, the use of the cylinder device 100 will be described. The cylinder device 100 can be used for any application that applies force to an object or accelerates the object. For example, the cylinder device 100 can be used for an object throwing device.
FIGS. 7A and 7B are views showing a mobile robot 200 using the cylinder device 100 as the anchoring device 4. The mobile robot 200 is used for throwing the tether 2 at a place where a human cannot approach and acquiring information on the place. Tether refers to members such as ropes, tubes, and strings.

  The mobile robot 200 includes a tether 2, a throwing device 4, an adsorbent or a weight (hereinafter referred to as a slave unit) 6, and a tether collecting device 150. A handset 6 is attached to the tip of the tether 2. The anchoring device 4 includes the cylinder device 100 described above. As described above, when the piston is fixed and air is compressed into the cylinder and the piston is opened, kinetic energy is given from the piston to the slave unit 6 in accordance with the expansion of the compressed air, and the slave unit 6 releases it vigorously. Is done. The tether 2 is accommodated in the tether collection device 150, and the pinch roller of the tether collection device 150 is opened when the handset 6 is thrown.

  When the handset 6 reaches the search location, the camera can be fed using the tether 2 as a guide. Alternatively, if the tether 2 is a tube, the sample can be collected by sucking the gas around the search location.

  A tapered case 8 is provided at the tip of the rod 28 of the anchoring device 4. A part of the tether 2 is spirally accommodated inside the tether recovery device 150 and is also spirally accommodated in the tapered case 8 at the tip. The taper case 8 is divided into a plurality of members whose cross sections are arcs, and can be expanded radially when throwing. The tapered case 8 is preferably developed when the cylinder is extended to the longest.

  The above is the configuration of the anchoring device 4. By using the above-described cylinder device 100 as the anchoring device 4, it becomes possible to apply a large force to the child device 6, and the child device 6 can be thrown far away or highly. Moreover, since the force given to the subunit | mobile_unit 6 can be controlled according to each mode of the cylinder apparatus 100, a throwing distance and height can be controlled.

  Furthermore, at the time of throwing, kinetic energy is given not only to the slave unit 6 but also to the portion 2a accommodated in the tapered case 8 of the tether 2, so that it is farther away than when the tether 2 is not accommodated at the tip. The handset 6 can be thrown.

  Although the present invention has been described using specific terms based on the embodiments, the embodiments only illustrate the principles and applications of the present invention, and the embodiments are defined in the claims. Many variations and modifications of the arrangement are permitted without departing from the spirit of the present invention.

2 ... Tether, 4 ... Throwing device, 6 ... Slave unit, 100 ... Cylinder device, 12 ... Cylinder tube, 14 ... Piston, 15 ... Magnetic material, 16 ... Pressure receiving surface, 18 ... Internal space, 18a ... First space, 18b 2nd space, 20 ... Tank, 22 ... Magnet, 24 ... 1st valve, 26 ... 2nd valve, 28 ... Rod, 30 ... Tip, 32 ... 1st opening, 34 ... 2nd opening, 36 ... O-ring 38 ... 1st adapter, 40 ... 2nd adapter, 42 ... Opening, 150 ... Tether collection | recovery apparatus, 200 ... Mobile robot.

Claims (6)

A cylinder tube provided with a first opening and a second opening at its bottom;
A piston provided in the cylinder tube so as to be capable of sliding back and forth in the axial direction;
A tank containing gas,
A first valve provided in a path for injecting gas into the tank;
A second valve provided in a path for injecting gas into the internal space of the cylinder tube through the second opening;
A magnet provided on the bottom surface of the cylinder tube, and attracting the piston to the bottom surface side of the cylinder tube;
With
In a state where the piston is attracted to the bottom surface of the cylinder tube by the magnet, a space formed by the pressure receiving surface of the piston and the inner wall of the cylinder tube in the cylinder tube is connected to the tank through the first opening. A cylinder device, wherein the cylinder device is partitioned into a first space that communicates with a second space that communicates with the second valve via the second opening. A first mode in which gas is injected into the tank with both the first valve and the second valve opened;
A second mode in which the first valve is opened, gas is injected into the tank with the second valve closed, and then the second valve is opened;
The cylinder device according to claim 1, wherein the cylinder device can be switched.   In addition to the first and second modes, the third valve can be switched to a third mode in which the first valve is opened and gas is continuously injected into the tank with the second valve closed. The cylinder device according to claim 2. One of the first opening and the second opening is provided at the center of the bottom surface of the cylinder tube,
4. The cylinder device according to claim 1, wherein the other of the first opening and the second opening is provided on the outer peripheral side of the bottom surface of the cylinder tube. 5. The first opening is provided on a side surface of the cylinder tube,
The cylinder device according to any one of claims 1 to 3, wherein the second opening is provided at a center of a bottom surface of the cylinder tube.   A anchoring device comprising the cylinder device according to any one of claims 1 to 5.

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