JP2009067530A - Gas spring type balancer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve general versatility, by adjusting to increase/decrease a maximum urging force without changing a charge amount of compressed gas, in a gas spring type balancer. <P>SOLUTION: The gas spring type balancer comprises: a push type gas spring 11 urging a rod member 14 in a direction get out of a main body case 12 by charged compressed gas; a cylinder member 50 having a cylinder chamber 52 communicating with a gas operation chamber 13 of the gas spring; a piston member 54 housed in the cylinder chamber 52 to be axially movable and receiving compressed gas pressure of the cylinder chamber 52; and a piston position adjusting mechanism 55 changing an axial position of the piston member 54 continuously to adjust the compression gas pressure in the gas operation chamber 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gas spring balancer incorporating a pull-type or push-type gas spring, and more particularly to a gas spring balancer that can adjust the maximum urging force without changing the filling amount of compressed gas.

  Conventionally, in a factory that manufactures or handles heavy products, it is a balancer that is connected to a hook of an overhead crane or the like to lift and move a heavy object and easily Various literatures have proposed balancers that can be attached and detached and that can easily finely adjust the position of an object by hand when the object is conveyed and positioned at a predetermined position.

  Here, the balancer includes a main body that generates an urging force equal to the weight of an object, and a pair of upper and lower suspension pieces connected to a hook or the like. In this type of balancer, compressed gas or pressurized An urging force is generated by air or hydraulic pressure.

  For example, in the balancer device of Patent Document 1, a biasing force for balance is generated by a double-acting expansion / contraction cylinder into which fluid pressure (pressurized air or hydraulic pressure) supplied from an external device is introduced. Locking means that prohibits the extension operation of the piston rod relative to the outer cylinder is provided on the telescopic case member that covers the telescopic cylinder. And the balancer device is made to function.

  In the weight automatic sensing balance lifting apparatus described in Patent Document 2, a double-acting air cylinder capable of suspending an object and an air circuit including a pressure regulating valve for adjusting the air pressure in the air working chamber of the air cylinder are provided. An urging force that balances with the weight of the object is generated by adjusting the air pressure in the air working chamber so that the air pressure is in accordance with the weight of the object. The air balancer disclosed in Patent Document 3 has substantially the same configuration as the balance lifting device disclosed in Patent Document 2.

JP-A-8-165100 Japanese Unexamined Patent Publication No. 7-101700 JP-A-11-228100

However, in the balancer device described in Patent Document 1, a hose or the like for supplying air or hydraulic pressure is connected to an expansion cylinder from an external air supply source or hydraulic supply source, and pressurized air or hydraulic pressure supplied to the expansion cylinder is reduced. By adjusting, the device becomes larger in order to adjust the urging force.
Furthermore, the balancer device is used in a state in which a hose or the like is connected, and hose handling for processing the hose becomes troublesome. In the case of the balancer devices of Patent Documents 2 and 3, the above problem remains.

Further, in the case of a gas spring type balancer in which compressed gas is filled and sealed in a gas working chamber in advance and a biasing force is generated by the gas pressure when the compressed gas is compressed, an external gas is used when the balancer is used. The hose is not required because it is not connected to a supply source.
In the push type gas spring type balancer that urges the rod member in the direction to advance the rod member from the main body case by the compressed gas, when the object is suspended, the rod member immediately moves back and forth slightly with respect to the main body case. The urging force by the compressed gas is equal to the weight of the object.

However, in this balancer, the maximum biasing force is determined according to the gas pressure of the compressed gas filled in the gas spring. That is, when the object is suspended and the rod member moves back and forth according to its weight and moves back to the stroke limit, the gas pressure of the compressed gas becomes the maximum pressure, and this biasing force is the maximum biasing force. Become.
In this type of conventional compressed gas-filled balancer, the maximum urging force cannot be increased or decreased without changing the filling amount of the compressed gas, so that the versatility of the balancer cannot be improved.

  An object of the present invention is to increase the versatility of a balancer by making it possible to adjust the maximum urging force without changing the filling amount of compressed gas in a gas spring balancer.

  The gas spring type balancer according to claim 1 is a gas spring type balancer used for suspending an object by being connected to a suspension part of a suspension means for suspending an object, wherein the gas spring is filled with a compressed gas. A cylinder member having a cylinder chamber communicated with the gas working chamber of the gas spring, a piston member that is movably housed in the axial direction of the cylinder chamber and receives the compressed gas in the cylinder chamber, and the gas working chamber In order to adjust the gas pressure of the compressed gas, a piston position adjusting mechanism capable of changing the axial direction position of the piston member steplessly is provided.

  In this gas spring type balancer, when an object heavier than the maximum urging force by the compressed gas filled in the gas spring is suspended, the position of the cylinder member is changed by changing the axial position of the piston member by the piston position adjusting mechanism. The gas pressure of the compressed gas in the cylinder chamber is adjusted, and accordingly, the gas pressure of the compressed gas in the gas working chamber of the gas spring is adjusted. Therefore, the maximum urging force can be increased or decreased without changing the filling amount of the compressed gas.

  According to a second aspect of the present invention, there is provided the gas spring type balancer according to the first aspect, wherein the gas spring includes a main body case, a piston portion slidable in a cylinder hole of the main body case, and a rod side of the main body case extending from the piston portion. It has a rod member having a rod portion that extends through the end wall portion and extends to the outside, and a gas working chamber defined in the cylinder hole, and is attached in a direction in which the rod member is retracted into the main body case by compressed gas. It is characterized by being a pull type gas spring.

  According to a third aspect of the present invention, there is provided the gas spring type balancer according to the first aspect, wherein the gas spring includes a main body case and a rod portion that is attached to the main body case and extends to the outside through the rod side end wall member of the main body case. A push-type gas spring that has a gas working chamber defined in the main body case and urges the rod member in a direction in which the rod member is advanced from the main body case by compressed gas.

  A gas spring type balancer according to a fourth aspect of the present invention is the gas spring type balancer according to any one of the first to third aspects, wherein the piston position adjusting mechanism is capable of supporting the force of the compressed gas that is screwed into the cylinder member and acts on the piston member. A shaft member is provided.

  The gas spring type balancer according to claim 5 is characterized in that, in the invention according to claim 4, a hexagonal tool engaging portion is formed at an outer end portion of the operation shaft member.

  According to a sixth aspect of the present invention, there is provided the gas spring type balancer according to the fifth aspect, wherein a pressure gauge is provided to indicate the pressure of the compressed gas in the gas working chamber of the gas spring.

  According to a seventh aspect of the present invention, there is provided the gas spring type balancer according to the fifth aspect, wherein a gas discharge valve capable of discharging the compressed gas in the gas working chamber of the gas spring is provided.

  According to the first aspect of the present invention, the gas spring filled with the compressed gas, the cylinder member having the cylinder chamber communicated with the gas working chamber of the gas spring, and the cylinder housed in the cylinder chamber so as to be movable in the axial direction thereof. Since the piston member that receives the compressed gas in the chamber and the piston position adjustment mechanism that can change the axial direction position of the piston member steplessly in order to adjust the gas pressure of the compressed gas in the gas working chamber, By changing the position of the piston member in the axial direction by the piston position adjusting mechanism, the maximum urging force can be increased or decreased without changing the amount of compressed gas filling. As a result, even when an object heavier than the maximum urging force by the compressed gas filled in the gas spring is suspended, an optimum urging force can be generated according to the weight of the object, and the urging force by the compressed gas can be increased. It is possible to maintain a balanced state in which the weight of the object is equal. Therefore, the versatility of the balancer is increased.

  In addition, the structure of adjusting the axial pressure of the piston member to adjust the gas pressure of the compressed gas in the gas working chamber eliminates the need for a compressed gas supply hose and its hose handling, Since the gas pressure can also be increased, the device is small.

  According to invention of Claim 2, a gas spring is a pull type gas spring which has a main body case, a rod member, and a gas working chamber, and is urged | biased in the direction which retracts a rod member to a main body case with compressed gas. Therefore, the effect of claim 1 can be obtained in the pull type gas spring.

  According to the invention of claim 3, the gas spring is a push-type gas spring that has a main body case, a rod portion, and a gas working chamber, and urges the rod member in a direction to advance from the main body case by compressed gas. In the push type gas spring, the effect of claim 1 can be obtained.

  According to the invention of claim 4, since the piston position adjusting mechanism includes the operation shaft member that can be screwed into the cylinder member and can support the force of the compressed gas acting on the piston member, the operation shaft member is rotated. It is possible to easily increase or decrease the maximum urging force.

  According to the invention of claim 5, since the hexagonal tool engaging portion is formed at the outer end portion of the operation shaft member, the tip end portion of the tool is fitted to the tool engaging portion of the operation shaft member. By operating with, the maximum biasing force can be easily adjusted.

  According to the invention of claim 6, since the pressure gauge for indicating the pressure of the compressed gas in the gas working chamber of the gas spring is provided, the operator operates the operation shaft member while looking at the pressure gauge, thereby compressing The gas pressure of the gas can be easily adjusted to the desired gas pressure.

  According to the seventh aspect of the present invention, since the gas release valve capable of releasing the compressed gas in the gas working chamber of the gas spring is provided, the object lighter than the urging force by the compressed gas filled in the gas spring is suspended. In addition, by releasing the compressed gas in the gas working chamber of the gas spring via the gas release valve, it is possible to easily and surely reduce the amount of compressed gas filling in the gas working chamber and reduce the urging force by the compressed gas. it can.

  Hereinafter, the best mode for carrying out the present invention will be described.

  As shown in FIG. 1, an overhead crane 1 (which corresponds to a suspension means) installed on the ceiling side of a building includes an operation unit 2, a main body 3, a trolley 4, a wire 5, a hook 6, and the like. An upper hook 6 (which corresponds to a suspension part) is provided at the lower end of the wire 5 extending downward from 4, a heavy object 9 is supported by a rope 8, and a lower hook 7 is provided at the upper end of the rope 8. A gas spring type balancer 10 is interposed between the upper hook 6 and the lower hook 7. In a state where the object 9 is suspended by the overhead crane 1 via the gas spring balancer 10, the rod of the gas spring balancer 10 is applied until an urging force equal to the weight of the object 9 is generated by the compressed gas of the gas spring. The portion 16 is slightly retracted, and the gas pressure of the compressed gas is automatically adjusted, and the urging force and the weight of the object 9 are balanced.

Next, the gas spring type balancer 10 will be described with reference to the drawings.
As shown in FIGS. 2 and 3, the gas spring type balancer 10 includes a push type gas spring 11 filled with compressed gas, a first suspension piece 44, a second suspension piece 45, and a frame body 30. Two cylinder members 50 having a cylinder chamber 52 communicated with the gas working chamber 13 of the gas spring 11, and two cylinder members 52 movably accommodated in the axial direction of the cylinder chamber 52 and receiving the compressed gas in the cylinder chamber 52. In order to adjust the gas pressure of the compressed gas in the gas working chamber 13, the piston member 54 includes two piston position adjusting mechanisms 55 that can change the axial position of the piston member 54 steplessly.

The push type gas spring 11 has a main body case 12, a rod member 14, and a gas working chamber 13. The rod member 14 includes a piston portion 15 and a rod portion 16 that is attached to the main body case 12 and extends through the rod-side end wall portion 19 of the main body case 12. The gas working chamber 13 is partitioned in the main body case 12 by the main body case 12 and the rod member 14, and the gas working chamber 13 is filled and filled with a compressed gas (for example, 7 to 13 MPa nitrogen gas).
The rod member 14 of the push type gas spring 11 is urged in a direction to advance from the main body case 12 by the compressed gas.

  The main body case 12 includes a cylinder main body 17, a head side end wall portion 18 and a rod side end wall portion 19 that block the upper and lower portions of the cylinder main body 17, respectively. A head-side end wall portion 18 is welded to the upper end portion of the cylinder body 17, and a rod-side end wall portion 19 is fitted and fixed to the lower end portion via an annular ring 21. The upper end portion of the head side end wall portion 18 is firmly fixed to the central portion of the lower end surface of the third plate member 35 by two bolts. The rod side end wall portion 19 is provided with a through hole 19a, and the rod portion 16 of the rod member 14 is inserted into the through hole 19a so as to be slidable in the vertical direction.

  The gas working chamber 13 is formed in the main body case 12 by the main body case 12 and the rod member 15, and the gas working chamber 13 is filled and filled with compressed gas. The gas working chamber 13 is filled with compressed gas through a gas filling valve 38 and a gas filling hole 39 attached to a connecting portion between the head side end wall portion 18 and the third plate member 35. A small amount of lubricating oil L for sealing so that the compressed gas does not leak is stored in the lower end portion in the gas working chamber 13.

  The third plate member 35 is formed in an octagonal shape in plan view, and two cylinder members 50 are firmly fixed to the left and right end portions of the lower end surface of the third plate member 35 by four bolts 51, respectively. Yes. A gas passage 35a extending in the left-right direction is provided inside the third plate member 35, and a gas introduction port incorporating a gas charge valve for introducing compressed gas on the upstream side (right end portion) of the gas passage 35a. 37 is provided.

  The rod portion 16 extends downward through the rod-side end wall portion 19 below the cylinder body 17, and the tip end surface of the rod portion 16 is in contact with the upper surface of the first plate member 33. An annular seal member 22 a that seals the sliding gap with the rod portion 16 in a gas-tight manner is attached to the inner peripheral portion of the sleeve body 20 that forms the rod-side end wall portion 19. Is provided with an annular seal member 22b for gas tightly sealing between the sleeve body 20 and the cylinder body 17. A rod guide ring 23 and a dust seal 24 for guiding the rod member in the vertical direction are mounted below the annular seal member 22a.

  The frame body 30 is configured by a first frame body 31 and a second frame body 32 so as to be extendable and contractable in the length direction of the gas spring 11, and the push-type gas spring 11 is incorporated in the frame body 30. ing. First and second plate members 33 and 34 are disposed on one end side of the gas spring 11 in order from the gas spring 11 side so as to be orthogonal to the axis of the gas spring 11, and on the other end side of the gas spring 11 side of the gas spring 11. The third and fourth plate members 35 and 36 are arranged in order from the axial center of the gas spring 11. The gas spring 11 is interposed between the first and third plate members 33 and 35 in a compressed state, the main body case 12 abuts against the lower surface of the third plate member 35, and the tip of the rod member 14 is the first plate member 33. Abut.

  The first frame 31 includes four pieces that slidably pass through the first plate member 33, the fourth plate member 36, and the third plate member 35 and connect the first and fourth plate members 33, 36. And the first tie rod 42. The second frame 32 includes four pieces that slidably pass through the second plate member 34, the third plate member 35, and the first plate member 33 and connect the second and third plate members 34, 35. Of the second tie rod 43.

  The first tie rod 42 is slidably inserted through the insertion hole of the third plate member 35, and the lower end small diameter portion 42 a of each tie rod 42 is inserted into the hole of the first plate member 33 and fixed by the nut 46. Is inserted into the hole of the fourth plate member 36 and fixed by the nut 46. The second tie rod 43 is slidably inserted through the insertion hole of the first plate member 33, and the lower end small diameter portion 43 a of each tie rod 43 is inserted into the hole of the second plate member 34 and fixed by the nut 47. The upper-end small-diameter portion is inserted into the hole of the third plate member 35 and fixed with a nut.

  A mounting hole 34a for the first suspension piece 44 is provided in the second plate member 34, and a bolt portion of the first suspension piece 44 is screwed into the mounting hole 34a. A mounting hole 36a for the second suspension piece 45 is provided in the fourth plate member 36, and a bolt portion of the second suspension piece 45 is screwed into the mounting hole 36a. The upper ends of the two cylinder members 50 are fixed to the lower surfaces of the left and right end portions of the third plate member 35, respectively.

Next, the cylinder member 50 will be described.
As shown in FIG. 3, a cylinder chamber 52 communicated with the gas working chamber 13 of the gas spring 11 is provided inside the cylinder member 50, and the cylinder chamber 52 has a compressed gas (for example, a nitrogen gas of 7 to 13 MPa). ) Is filled and enclosed. A gas filling hole 53 communicating with the cylinder chamber 52 is provided at the upper end portion of the cylinder member 50, and the gas passage 35 a and the connecting portion between the cylinder member 50 and the third plate member 35 are mounted in the cylinder chamber 52. The compressed gas is filled through the gas filling valve 40 and the gas filling hole 53. A small amount of lubricating oil L for sealing so that the compressed gas does not leak is stored in the lower end portion in the cylinder chamber 52.

  A screw hole 50a communicating with the cylinder chamber 52 is provided at the lower end portion of the cylinder member 50, and an operation shaft member 56 is screwed into the screw hole 50a. A piston member 54 is fixed to the upper end of the operation shaft member 56 via a steel ball 57, and the operation shaft member 56 is rotated so that the axial center position of the piston member 54 can be changed steplessly. Yes. The operation shaft member 56 is configured to be able to support the force of compressed gas acting on the piston member 54. The operation shaft member 56 and the steel ball 57 correspond to the piston position adjusting mechanism 55.

  A hexagonal tool engaging portion 56a is formed at the outer end portion of the operation shaft member 56, and a tip portion of an electric screwdriver (not shown) is fitted therein. When the object 9 that is heavier than the maximum urging force by the compressed gas filled in the gas spring 11 is suspended, the tip of the electric screwdriver is fitted to the tool engaging portion 56a of the operation shaft member 56, and then the operation shaft member. When the piston member 54 is moved upward by rotating 56, the gas pressure in the cylinder chamber 52 is increased, and accordingly, the gas pressure in the gas working chamber 13 is increased and the maximum urging force by the compressed gas is improved. .

  As shown in FIG. 2, a pressure gauge 48 that indicates the pressure of the compressed gas in the gas working chamber 13 of the gas spring 11 is provided on the front surface of the upper end portion of the left cylinder member 50. A gas release valve 49 capable of releasing the compressed gas in the gas working chamber 13 of the gas spring 11 is provided in front of the upper end portion of the right cylinder member 50. When the object 9 having a lighter weight than the urging force by the compressed gas is suspended, the compressed gas in the gas working chamber 13 is released through the gas release valve 49 and the gas pressure in the gas working chamber 13 is reduced to compress the object 9. Reduce the urging force of gas.

Next, changes in the urging force when the gas pressure of the compressed gas is not adjusted, when the gas pressure is adjusted by one cylinder member 50, and when the gas pressure is adjusted by two cylinder members 50 will be described.
FIG. 4 shows a case where only the rod member 14 of the gas spring 11 is moved by a half stroke, a case where the rod member 14 of the gas spring 11 and the piston portion 54 of one cylinder member 50 are moved by a half stroke, It is a diagram which shows the change of the urging | biasing force at the time of moving the piston member 54 of the rod member 14 and the two cylinder members 50 by a half stroke.

  As shown in FIG. 4, for example, when the filling pressure of the compressed gas is 7 MPa, when only the compressed gas of the gas spring 11 is compressed, an urging force of about 350 kgf acts, and the gas spring 11 and one cylinder member 50 When the compressed gas is compressed, an urging force of about 430 kgf acts, and when the compressed gas of the gas spring 11 and the two cylinder members 50 is compressed, an urging force of about 560 kgf acts. Thereby, compared with the case where the gas pressure of the compressed gas is not adjusted, the case where the gas pressure of the compressed gas is adjusted by one cylinder member 50, and the case where the gas pressure of the compressed gas is adjusted by two cylinder members 50 are further increased. It can be seen that a higher biasing force is obtained, and the heavier object 9 can be held in a balanced state. Furthermore, the urging | biasing force in said case each increases by increasing the filling pressure of the compressed gas of the gas spring 11 and the cylinder member 50, respectively.

Next, the operation and effect of the gas spring balancer 10 will be described.
The upper hook 6 of the overhead crane 1 is engaged with the second suspension piece 45, the lower hook 7 of the object 9 side is engaged with the first suspension piece 44, and the overhead crane 1 causes the object to pass through the balancer 10. Can be suspended. When the object 9 is suspended by the overhead crane 1 via the balancer 10, the object 9 is suspended via the gas balancer 10, and the weight of the object 9 acts on the rod member 14 of the gas spring 11 via the frame 30. For this reason, the rod member 14 slightly moves back and forth with respect to the main body case 17, and the urging force of the compressed gas and the weight of the object 9 are in a balanced state.

When an object heavier than the maximum urging force by the compressed gas filled in the gas spring 11 is suspended, the gas pressure is adjusted by one or two cylinder members 50. When the distal end portion of the electric screwdriver is fitted into the tool engaging portion 56a of the operation shaft member 56 and then the operation shaft member 56 is rotated to move the piston portion 54 upward, the gas pressure in the cylinder chamber 52 is increased. It is done.
Along with this, the gas pressure of the compressed gas in the gas working chamber 13 is increased, and the maximum urging force by the compressed gas is improved.

  Thus, the gas spring 11 filled with the compressed gas, the cylinder member 50 having the cylinder chamber 52 communicated with the gas working chamber 13 of the gas spring 11, and the cylinder chamber 52 are movably accommodated in the axial direction thereof. A piston member 54 that receives the compressed gas in the cylinder chamber 52 and a piston position adjusting mechanism that can change the axial position of the piston member 54 steplessly in order to adjust the gas pressure of the compressed gas in the gas working chamber 13. 55, the maximum urging force can be increased or decreased without changing the filling amount of the compressed gas by changing the axial position of the piston member by the piston position adjusting mechanism. Thereby, even when the object 9 heavier than the maximum urging force by the compressed gas filled in the gas spring 11 is suspended, an optimum urging force can be generated in accordance with the weight of the object 9, and the compressed gas is used. The urging force and the weight of the object 9 can be kept in a balanced state. Therefore, the versatility of the gas spring balancer 10 is enhanced.

  In addition, since the axial position of the piston member 54 is changed to adjust the gas pressure of the compressed gas in the gas working chamber 13, a hose for supplying compressed gas and its hose handling become unnecessary. Since the gas pressure of the compressed gas can be increased, the apparatus is small.

  Since the piston position adjusting mechanism 55 includes the operation shaft member 56 that can be screwed into the cylinder member 50 and can support the force of the compressed gas acting on the piston member 54, the maximum biasing force can be obtained by rotating the operation shaft member 56. Can be easily adjusted. Since the hexagonal tool engaging portion 56a is formed at the outer end portion of the operation shaft member 56, the operation is performed with the tip portion of the electric screwdriver fitted to the tool engaging portion 56a of the operation shaft member 56. Thus, the maximum biasing force can be easily adjusted.

  Since the pressure gauge 48 for instructing the pressure of the compressed gas in the gas working chamber 13 of the gas spring 11 is provided, the operator operates the operation shaft member 56 while looking at the pressure gauge 48, so that the gas pressure of the compressed gas is increased. Can be easily adjusted to the desired gas pressure. Since the gas release valve 49 capable of releasing the compressed gas in the gas working chamber 13 of the gas spring 11 is provided, when the object 9 that is lighter than the urging force by the compressed gas is suspended, the gas spring is passed through the gas release valve 49. By releasing the compressed gas in the eleven gas working chambers 13, the amount of the compressed gas filled in the gas working chamber 13 can be easily and reliably reduced to reduce the urging force of the compressed gas.

Next, the gas spring type balancer 10A according to the second embodiment will be described. However, the same reference numerals are given to the same components as those in the above embodiment, and only different components will be described.
As shown in FIG. 5, the gas spring type balancer 10A includes a pull type gas spring 60, a first suspension piece 77, a second suspension piece 78, two cylinder members 50, two piston members 54, Two piston position adjusting mechanisms 55 are provided.

  The pull type gas spring 60 has a main body case 61, a rod member 63, and a gas working chamber 62. The rod member 63 has a piston part 64, an extension part 64 a, and a rod part 65. An annular seal member 77 is attached to the piston portion 64.

  The piston portion 64 is slidably mounted in the cylinder hole 76 of the main body case 61, and the rod portion 65 extends downward from the piston portion 64 and extends to the outside through the rod side end wall portion 69 of the main body case 61. . The gas working chamber 62 is partitioned in the cylinder hole 76 by a main body case 61 and a rod member 63, and the gas working chamber 62 is filled and filled with compressed gas (for example, 7 to 13 MPa nitrogen gas). The gas spring 60 is a pull-type gas spring that urges the rod member 63 in a direction in which the rod member 63 is retracted from the main body case 61 by compressed gas. The gas pressure of the compressed gas filled and sealed in the gas working chamber 62 is desirably set to a gas pressure that is equal to or slightly lower than the gas pressure capable of supporting the weight of the object 9.

  The main body case 61 includes a cylindrical member 66, a head side end wall portion 68 and a rod side end wall portion 69 that block the upper and lower portions of the cylindrical member 66, and a peripheral wall member that forms a peripheral wall of the cylinder hole 76 inside the main body case 61. 67 etc. Below the upper end of the cylindrical member 66, the third plate member 35 is firmly fixed in a state where it penetrates. A head side end wall portion 68 is screwed to the upper end portion of the cylindrical member 66, and a rod side end wall portion 69 is screwed to the lower end portion. A breathing hole 27 for releasing the space defined by the cylindrical member 66 and the extension part 64 a of the piston part 64 to the atmosphere is provided in the upper part of the cylindrical member 66.

  An attachment hole 68a of the first suspension piece 77 is provided in the vicinity of the axial center of the head side end wall portion 68, and the bolt portion of the first suspension piece 77 is screwed into the attachment hole 68a. When the rod member 63 is retracted to the maximum with respect to the cylindrical member 66, the upper end surface of the extension portion 64 a is in contact with the lower end surface of the head side end wall portion 68. A through hole 69a is formed in the center side portion of the rod side end wall portion 69, and the rod portion 65 of the rod member 63 is inserted so as to be movable in the vertical direction. The peripheral wall member 67 and the lower end surface of the sleeve body 70 are in contact with the upper end surface of the rod side end wall portion 69.

  The peripheral wall member 67 is formed in a cylindrical shape having a smaller diameter than the cylindrical member 66, is fitted into the cylindrical member 66, and is strongly bonded to the cylindrical member 66 with, for example, an adhesive. At the upper end portion of the peripheral wall member 67, an annular lock that locks the piston portion 64 when the rod member 63 reaches the upper limit position and the upper end of the extension portion 64 a comes into contact with the lower surface of the head side end wall portion 68. A portion 67a is formed.

  The rod member 63 is formed with an extension portion 64a extending upward from the piston portion 64, and the extension portion 64a extends upward through the locking portion 67a. A gas filling hole 75 communicating with the gas working chamber 62 is formed in the vicinity of the center of the extension part 64a. A compressed gas filling valve 38 is provided in the gas filling hole 75, and the gas operation is performed via the gas filling valve 38. Chamber 62 is filled with compressed gas. It is desirable to store a small amount of lubricating oil L for sealing so that the compressed gas does not leak at the lower end in the gas working chamber 62.

  The rod portion 65 is slidably inserted into the inner peripheral surface of the sleeve body 70, extends through the rod side end wall portion 69 to the outside below the cylinder hole 76. The lower end portion of the rod portion 65 is formed to have a small diameter with the stepped portion as a boundary, and the second suspension piece 78 is fixed to the tip portion thereof.

  The sleeve body 70 is a detachable annular member that holds the inside of the gas working chamber 62 in an airtight manner, and is fitted and fixed to the lower end portion of the peripheral wall member 67 via an annular ring 71. An annular seal member 72a that seals the sliding gap with the rod portion 65 in a gas-tight manner is attached to the inner peripheral surface of the sleeve body 70, and the gas between the sleeve body 70 and the peripheral wall member 67 is attached to the outer peripheral surface. An annular seal member 72b for tightly sealing is mounted. Below the annular seal member 72a, a rod guide ring 73 and a dust seal 74 for guiding the rod member 63 so as to be slidable in the vertical direction are mounted.

Next, functions and effects of the gas spring type balancer 10A will be described.
Similar to the balancer 10 of the first embodiment, the upper hook of the overhead crane 1 is engaged with the first suspension piece 77, and the lower hook of the object 9 side is engaged with the second suspension piece 78. Thus, the object can be suspended through the balancer 10A. In the balancer 10A, since the rod member 63 is urged by the pull-type gas spring 60 in the direction in which the rod member 63 is retracted into the main body case 61, substantially the same operation and effect as the balancer 10 of the first embodiment can be obtained.

Next, a modified example in which the above embodiment is partially modified will be described.
1] In the first and second embodiments, two sets of the cylinder member 50, the piston member 54, and the piston position adjusting mechanism 55 are provided, but one set or two or more sets may be provided.
2] In the first and second embodiments, the suspension means is not limited to the overhead crane 1 but may be other suspension means such as a shiv crane, a crane truck, or a robot.
3] In the first and second embodiments, the gas springs 11 and 60 may be mounted upside down in the illustrated state.

4] In the first embodiment, instead of the frame body 30 having four tie rods 42 and 43, the frame body 30 may be configured by a pair of tie rods.
5] In addition, those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. .

1 is a schematic overall view of a gas spring type balancer according to a first embodiment of the present invention. It is a perspective view of a gas spring type balancer. It is a longitudinal cross-sectional view of a gas spring type balancer. It is a diagram which shows the change of the urging | biasing force in various compression states. It is a longitudinal cross-sectional view of the gas spring type balancer which concerns on Example 2. FIG.

Explanation of symbols

10, 10A Gas spring type balancer 11 Push type gas spring 12, 61 Main body case 13, 62 Gas working chamber 16 Rod portion 48 Pressure gauge 49 Gas release valve 50 Cylinder member 54 Piston member 55 Piston position adjusting mechanism 56 Operation shaft member 56a Tool Engagement part 60 Pull type gas spring 63 Rod member

Claims (7)

In a gas spring type balancer used for suspending an object connected to a suspension part of a suspension means for suspending an object,
A gas spring filled with compressed gas;
A cylinder member having a cylinder chamber communicated with a gas working chamber of the gas spring;
A piston member that is movably accommodated in the axial direction of the cylinder chamber and receives the compressed gas in the cylinder chamber;
A piston position adjusting mechanism capable of steplessly changing the axial position of the piston member in order to adjust the gas pressure of the compressed gas in the gas working chamber;
A gas spring type balancer characterized by comprising:   The gas spring includes a main body case, a rod member having a piston portion slidable in a cylinder hole of the main body case, and a rod portion extending from the piston portion and extending outward through the rod side end wall portion of the main body case. And a gas working chamber defined in the cylinder hole, and a pull-type gas spring that urges the rod member in a direction to retract the main body case by compressed gas. Gas spring type balancer.   The gas spring has a main body case, a rod portion that is attached to the main body case and extends to the outside through the rod side end wall member of the main body case, and a gas working chamber defined in the main body case, 2. The gas spring type balancer according to claim 1, wherein the gas spring type balancer is a push type gas spring that urges the rod member in a direction to advance the rod member from the main body case by compressed gas.   The gas according to any one of claims 1 to 3, wherein the piston position adjusting mechanism includes an operation shaft member capable of supporting the force of the compressed gas that is screwed into the cylinder member and acts on the piston member. Spring balancer.   The gas spring type balancer according to claim 4, wherein a hexagonal tool engaging portion is formed at an outer end portion of the operation shaft member.   The gas spring type balancer according to claim 5, further comprising a pressure gauge for indicating a pressure of a compressed gas in a gas working chamber of the gas spring.   6. The gas spring type balancer according to claim 5, further comprising a gas release valve capable of releasing a compressed gas in a gas working chamber of the gas spring.