JP2009085320A - Gas spring type balancer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas spring type balancer provided with an adjustment mechanism with a simple composition capable of easily adjusting a height position of a suspended object. <P>SOLUTION: The balancer 10 used for suspending an object connected to a suspending part of a suspending means is provided with a gas spring 11 filled with compressed gas, a first member 31 connected to the suspending part of the suspending means, a second member 32 connected to the first member 31 via the gas spring, connected to the suspended object, and facing the first member 31 via a variable space 40 enlarging as weight of the suspended object is increased, a hydraulic cylinder 46 arranged in the variable space 40 and operably connected to the first and second members, and the adjustment mechanism 45 provided with a pump mechanism adjusting an oil pressure of the hydraulic cylinder 46. It is composed such that the height position of the suspended object can be adjusted by adjusting the oil pressure of the hydraulic cylinder 46 by the pump mechanism 50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gas spring type balancer incorporating a push-type or pull-type gas spring, and more particularly to a type in which the height position of an object can be easily adjusted even when a heavy object is suspended.

  Conventionally, when a heavy object is moved by an overhead crane etc. in a factory or a warehouse, or loaded on a transport vehicle, the object can be easily fine-tuned manually at a predetermined position. In addition, various balancers for suspending an object by being connected to a suspension portion of a suspension means for suspending the object have been proposed and put into practical use.

  In general, the balancer includes a balancer body that generates a biasing force that supports the weight of an object by fluid pressure, a pair of upper and lower suspension pieces, and the like. This type of balancer is configured to generate an urging force by compressed gas, pressurized air, or hydraulic pressure.

  For example, in the balancer device of Patent Document 1, a biasing force for balance is generated by an expansion / contraction cylinder to which fluid pressure (pressurized air or hydraulic pressure) supplied from an external device is introduced, and a piston for the outer cylinder of the expansion / contraction cylinder is generated. Locking means that prohibits the rod extension operation is provided on the telescopic case member that covers the telescopic cylinder, and the heavy object can be transported safely with the extension operation prohibited, and the lock by the locking means is released after the transport movement. The balancer device is configured to function.

  However, the balancer device described above uses the balancer device with a hose that supplies pressurized air or hydraulic pressure from an external air supply source or hydraulic supply source to the telescopic cylinder. The hose handling for handling hoses is troublesome, and when using a hydraulic telescopic cylinder, a complicated balance control valve is required, and the control of the balance control valve to generate an urging force equal to the weight of the object is necessary. There are problems such as complexity and lack of practicality, such as a dull response to the hydraulic pressure supplied to the telescopic cylinder.

Therefore, in order to solve the above problem, the applicant of the present application has already put the gas spring balancer described in Patent Document 2 into practical use. This gas spring type balancer is a small balancer composed of a balancer main body in which a pull type and a push type gas spring are incorporated, and a pair of upper and lower suspension pieces, such as nitrogen gas sealed in the gas spring. It is a balancer that generates a biasing force that balances the weight of an object by means of compressed gas pressure, and is small and excellent in responsiveness.
JP-A-8-165100 Utility Model Registration No. 3133267

In the above gas spring type balancer, by using a balancer that incorporates a gas spring filled with compressed gas at a pressure corresponding to the weight of the object to be suspended, an urging force that balances the weight of the object is generated, and apparently The object can be suspended in a weightless state.
If the weight of the object is not very large, the gas pressure of the compressed gas in the gas spring is not high, so by pushing the object suspended by hand upward or downward, the vertical position of the object can be changed manually. Can be easily adjusted.

  However, when a heavy object of several tons is suspended, the gas pressure of the compressed gas in the gas spring is also high, and the change in the height position of the suspended object is relative to the cylinder body of the gas spring. Since it involves movement, it is necessary to apply a large force of several tens of kilograms or more to adjust the height position of an object of, for example, 4 mm or 5 mm. Therefore, a great deal of labor is required to adjust the height position of the object, and it is difficult to increase the work efficiency.

  An object of the present invention is to provide a gas spring type balancer provided with an adjustment mechanism having a simple configuration capable of easily adjusting the height position of a suspended object.

  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 first member coupled to a suspension part of the suspension means, and a second member coupled to the first member via the gas spring and coupled to the object to be suspended, A variable space that expands as the weight of the object to be held increases, a second member that faces the first member, and a variable space that is disposed in the variable space and operatively connected to the first and second members. An adjustment mechanism having a hydraulic cylinder and a pump mechanism for adjusting the hydraulic pressure of the hydraulic cylinder, and the hydraulic pressure of the hydraulic cylinder is applied by the pump mechanism of the adjustment mechanism, thereby enabling the height position of the suspended object to be set In Is characterized in that form was.

  In this gas spring type balancer, the suspension part of the suspension means is connected to the first member, the object to be suspended is connected to the second member, and the object is passed through this balancer by the suspension means such as a crane. When suspended, the rod member of the gas spring moves to a balance state until the urging force by the compressed gas filled in the gas working chamber of the gas spring balances the weight of the object. When this balance is reached, the weight of the object appears to be zero.

  When the height position of the object is adjusted upward or downward after the object is transported, the hydraulic pressure of the hydraulic cylinder is adjusted by the pump mechanism of the adjustment mechanism to adjust the size of the variable space (the rod member of the gas spring) The height position of the object can be easily adjusted. The pump mechanism may be configured to be driven manually or may be configured to be driven by an electric tool. In the state where the object is suspended and balanced and the vertical position is not adjusted, the hydraulic pressure of the hydraulic cylinder may be zero.

  According to a second aspect of the present invention, in the gas spring type balancer according to the first aspect of the invention, the hydraulic cylinder includes a cylinder body fixed to the first member and a rod member connected to the second member. It is a feature.

  According to a third aspect of the present invention, there is provided the gas spring balancer according to the first aspect, wherein the hydraulic cylinder includes a cylinder body fixed to the second member and a rod member connected to the first member. It is a feature.

  According to a fourth aspect of the present invention, there is provided the gas spring type balancer according to any one of the first to third aspects, wherein the pump mechanism forms a pump hole that is fixed to a cylinder body of the hydraulic cylinder and communicates with an oil chamber of the hydraulic cylinder. It is characterized by comprising a cylindrical member, a pressure member attached to the cylindrical member and capable of pressurizing the oil in the pump hole, and a pressure member driving mechanism capable of driving the pressure member. .

  A gas spring type balancer according to a fifth aspect of the present invention is the gas spring type balancer according to the fourth aspect of the invention, wherein the pressurizing member driving mechanism includes a screw hole formed in the cylindrical member and having a large lead angle thread groove formed on an inner peripheral surface thereof. And an operation member screwed into the screw hole.

  The gas spring type balancer according to claim 6 is the gas spring type balancer according to claim 5, 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. A rod member having a rod portion inserted through the end wall portion and extending to the outside, and a gas working chamber defined in the cylinder hole, in a direction in which the rod member is retracted into the main body case by the compressed gas. It is characterized by a pull-type gas spring that is energized.

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

  According to the first aspect of the present invention, the gas spring, the first member coupled to the suspension portion of the suspension means, the object coupled to the object to be suspended and coupled to the first member via the gas spring; A mechanism having a second member facing the first member with a variable space, a hydraulic cylinder disposed in the variable space and connected to the first and second members, and a pump mechanism for hydraulic pressure of the hydraulic cylinder; And the height position of the suspended object can be adjusted by applying the hydraulic pressure of the hydraulic cylinder by the pump mechanism of the adjusting mechanism, so that the following effects can be obtained.

  By adjusting the hydraulic pressure of the hydraulic cylinder by the pump mechanism of the adjusting mechanism and adjusting the length of the variable space by the hydraulic pressure, the vertical position of the object can be easily adjusted even for a heavy object. Can do. The pump mechanism may be driven manually or with a power tool, but the height position of the object can be easily and efficiently adjusted by an adjustment mechanism with a simple configuration, thereby improving work efficiency. be able to. Further, since the adjustment mechanism employs a hydraulic cylinder, it can be configured to be small.

  According to the invention of claim 2, the hydraulic cylinder includes a cylinder body fixed to the first member and a rod member connected to the second member, so that the hydraulic pressure in the hydraulic cylinder is adjusted. Thus, the length of the variable space between the first and second members can be adjusted by the rod member that moves forward and backward with respect to the cylinder body, and the height position of the object can be adjusted.

  According to the invention of claim 3, the hydraulic cylinder includes a cylinder main body fixed to the second member and a rod member connected to the first member. The length of the variable space between the first member and the second member can be adjusted, and the height position of the object can be adjusted.

  According to the invention of claim 4, the pump mechanism includes a cylindrical member that forms a pump hole communicating with the oil chamber of the hydraulic cylinder, a pressurizing member that can pressurize the oil in the pump hole, and the pressurizing member. Since the pressure member driving mechanism capable of driving the member is provided, the pressure member is driven by the pressure member driving mechanism, and the hydraulic pressure communicating with the pump hole is adjusted by adjusting the hydraulic pressure in the cylindrical pump hole. The hydraulic pressure in the oil chamber of the cylinder can be adjusted.

  Therefore, when adjusting the height position of the object, the pressure member is driven, the rod member of the hydraulic cylinder is driven, and the length of the variable space is adjusted. Since a hydraulic cylinder is employed as the adjustment mechanism, the adjustment mechanism can be reduced in size.

  According to the invention of claim 5, the pressurizing member driving mechanism includes a screw hole in which a screw groove having a large lead angle is formed on the inner peripheral surface of the cylindrical member, and an operation member screwed into the screw hole. Therefore, the advancement / retraction amount of the rod member relative to the cylinder body of the hydraulic cylinder is determined according to the length of the variable space when the object is suspended, and the operation member is automatically moved in the screw hole according to the advancement / retraction amount. The hydraulic pressure of the hydraulic cylinder is almost zero. When adjusting the height position of the object, a hydraulic pressure (positive pressure, negative pressure) is generated in the hydraulic cylinder in order to operate the pump mechanism.

  According to the invention of claim 6, since this gas spring is a pull-type gas spring that urges the rod member in the direction of retracting the main body case by the compressed gas, the structure of the balancer can be simplified and miniaturized. Can be manufactured at low cost.

  According to the invention of claim 7, since this gas spring is a push type gas spring that urges the rod member in the direction to advance the rod member from the main body case by the compressed gas, the number of seal portions around the gas working chamber of the gas spring is reduced. In addition, the leakage of the compressed gas filled and sealed in the gas working chamber can be reduced, and maintenance costs such as filling of the compressed gas can be reduced.

The best mode for carrying out the present invention will be described below with reference to the drawings.
The gas spring type balancer of the present invention is used to suspend an object connected to a suspending portion of a suspension means for suspending an object in a factory, a warehouse, around a transportation vehicle, etc. In particular, it is suitable for suspending a heavy object of 1 ton or more.

  As shown in FIG. 1, an overhead crane 1 (corresponding to a suspension means) installed on the ceiling side of a building is equivalent to a driving unit 2, a main body 3, a trolley 4, a wire 5, and a hook 6 (corresponding to a suspension unit). ) And the like, and an upper hook 6 is provided at the lower end of the wire 5 extending downward from the trolley 4, a heavy object 9 is supported by the rope 8, and a lower hook 7 is provided at the upper end of the rope 8. A gas spring balancer 10 is interposed between the hook 6 and the lower hook 7, and the object 9 is suspended and conveyed by the overhead crane 1 via the balancer 10.

  In the state where the object 9 is suspended by the overhead crane 1 via the balancer 10, the rod member of the balancer 10 until the urging force that balances the weight of the object 9 is generated by the compressed gas in the gas working chamber 27 of the gas spring 11. 23 enters and the gas pressure of the compressed gas is automatically adjusted, the urging force and the weight of the object 9 are balanced, and the weight of the object 9 apparently becomes zero.

  As shown in FIGS. 2 to 4, the balancer 10 includes a push-type gas spring 11, a frame body 30, a first suspension piece 41, a second suspension piece 42, a hydraulic cylinder 46, and a pump mechanism 50. And an adjusting mechanism 45 having The balancer 10 is configured to be able to adjust the height position of the suspended object 9 by adjusting the hydraulic pressure of the hydraulic cylinder 46 by the pump mechanism 50 of the adjusting mechanism 45.

First, the push type gas spring 11 will be described.
The push type gas spring 11 has a main body case 12, a rod member 23, and a gas working chamber 27. The rod member 23 of the gas spring 11 is urged in a direction to advance upward from the main body case 12 by compressed gas (for example, compressed nitrogen gas of 5 to 15 MPa) filled in the gas working chamber 27 in the main body case 12. ing.

  The body case 12 includes a cylinder body 13, a head side end wall portion 14, and a rod side end wall portion 15. The cylinder body 13 is fixed to the upper surface of the third plate member 35 with a plurality of bolts. The rod side end wall portion 15 has a through hole 17, and the rod portion 25 of the rod member 23 is inserted into the through hole 17 so as to be slidable in the vertical direction. The rod-side end wall portion 15 is fitted and fixed to the upper end portion of the cylinder body 13 via a C-shaped ring member 20.

  An annular seal member 21 a that seals between the cylinder body 13 and the cylinder body 13 is attached to the outer peripheral portion of the rod-side end wall portion 15, and the inner peripheral portion of the rod-side end wall portion 15 is connected to the rod portion 25. An annular seal member 21b that seals the sliding gap in a gas-tight manner is mounted. A dust seal 22 is mounted above the annular seal member 21b.

  The rod member 23 includes a flange portion 24 and a rod portion 25 that is integrally formed with the flange portion 24 and extends through the rod side end wall portion 15. The rod portion 25 is inserted through the rod-side end wall portion 15 by compressed gas pressure and extends upward, and the tip end surface of the rod portion 25 is in contact with the lower end surface of the second plate member 34.

  The gas working chamber 27 is formed inside the cylinder body 13, and into the gas working chamber 27, a gas filling hole 28 provided in the head side end wall portion 14 and a gas filling attached to the gas filling hole 28. The compressed gas is filled through the valve 29.

Next, the frame 30 will be described.
The frame body 30 is configured by a first frame body 31 and a second frame body 32 so that the frame body 30 can expand and contract in the longitudinal direction of the gas spring 11. The frame body 30 incorporates an adjustment mechanism 45 that can adjust the length of the gas spring 11 and the frame body 30.

  On one end side of the gas spring 11, first and second plate members 33 and 34 are arranged in order from the upper side so as to be orthogonal to the axis of the gas spring 11. On the other end side of the gas spring 11, third and fourth plate members 35 and 36 are disposed in order from the gas spring 11 in a shape orthogonal to the axis of the gas spring 11. The gas spring 11 is interposed between the second and third plate members 34 and 35 in a state where the rod member 23 has advanced to the maximum extent, the main body case 12 is fixed to the upper surface of the third plate member 35, and the tip of the rod member 23 is Is in contact with the lower surface of the second plate member 34.

  In this state, the first and second plate members 33 and 34 are in contact with each other, and a variable space 40 having a variable length is formed between the third and fourth plate members 35 and 36. In the state of FIG. 4, the variable space 40 is expanded to the maximum length. The adjusting mechanism 45 is mounted in the variable space 40 between the third and fourth plate members 35 and 36. In the state shown in FIG. 2, the rod member 48 of the adjusting mechanism 45 is in a fully retracted state. . The third plate member 35 corresponds to a “first member”, and the fourth plate member 36 corresponds to a “second member”.

  The first frame 31 includes four pieces that slidably pass through the first plate member 33, the third plate member 35, and the second plate member 34 to connect the first and third plate members 33, 35. Of the first tie rod 37.

  The second frame 32 includes four pieces that slidably pass through the second plate member 34, the fourth plate member 36, and the third plate member 35 and connect the second and fourth plate members 34 and 36. And the second tie rod 38. The second frame 32 is connected to the first frame 31 via the gas spring 11, and the fourth plate member 36 of the second frame 32 increases as the weight of the object 9 to be suspended increases. The variable space 40 to be enlarged is left facing the third plate member 35 of the first frame 31.

  The upper end portion of the first tie rod 37 passes through the first plate member 33 and is fixed by the nut 33a, and the lower end small diameter portion of the first tie rod 37 passes through the third plate member 35 and is fixed by the nut 35a. The upper end portion of the second tie rod 38 passes through the second plate member 34 and is fixed by a nut 34a, and the lower end portion of the second tie rod 38 passes through the fourth plate member 36 and is fixed by a nut 36a.

The bolt portion of the first suspension piece 41 is screwed to the first plate member 33, and the bolt portion of the second suspension piece 42 is screwed to the fourth plate member 36.
The upper hook 6 is hung on the first hanging piece 41, the lower hook 7 is hung on the second hanging piece 42, and the object 9 is suspended by the overhead crane 1 via the balancer 10.

Next, the adjustment mechanism 45 for adjusting the height position of the object 9 will be described.
The adjustment mechanism 45 includes a hydraulic cylinder 46 and a pump mechanism 50. The hydraulic cylinder 46 is disposed vertically in the variable space 40 and is operatively connected to the fourth plate member 36 and the third plate member 35. The pump mechanism 50 can adjust the hydraulic pressure of the hydraulic cylinder 46 in a state where the object 9 is suspended, and the length of the variable space 40 is adjusted and suspended by adjusting the hydraulic pressure by adjusting the hydraulic pressure. The height position of the object 9 can be adjusted.

  The hydraulic cylinder 46 includes a cylinder body 47 and a rod member 48 inserted into the cylinder body 47. The cylinder body 47 is vertically fixed to the upper surface of the fourth plate member 36. The rod member 48 is connected to the lower surface of the third plate member 35 in a vertical posture. An oil chamber 49 is formed inside the cylinder body 47, and the oil chamber 49 is filled with oil. An end portion of the pump mechanism 50 is attached to the through hole 47 a on the side of the cylinder body 47, and the pump mechanism 50 is fixed to the cylinder body 47 in a liquid-tight manner orthogonally. An annular seal member 47 b that holds the oil chamber in a liquid-tight manner is attached to the insertion hole 47 c in the upper part of the cylinder body 47.

The pump mechanism 50 includes a horizontal cylindrical member 51, a pressure member 53, and a pressure member drive mechanism 56. The end of the cylindrical member 51 is fixed to the cylinder body 47 in a horizontal posture.
The cylindrical member 51 has a cylinder portion 51a in the left half portion and a screw cylinder portion 51b in the right half portion. The cylinder part 51 a forms a pump hole 52 communicating with the oil chamber 49 of the hydraulic cylinder 46, and the pump hole 52 is filled with oil. A piston portion 54 as a pressurizing member 53 that partitions the right end of the pump hole 52 is slidably mounted on the cylinder portion 51a. A pressure member driving mechanism 56 is screwed into the screw cylinder portion 51b in a loose fit.

The pressurizing member 53 has a piston portion 54 and a rod portion 55 integrated with the piston portion 54. An annular seal member 54 a that holds the pump hole 52 in a liquid-tight manner is attached to the piston portion 54.
By driving the pressurizing member 53 by the pressurizing member driving mechanism 56, the hydraulic pressure in the pump hole 52 can be adjusted. The right end portion of the rod portion 55 is connected to the center portion of the left end of the pressure member driving mechanism 56 so that it can be driven integrally.

  The pressure member driving mechanism 56 includes a screw hole 57 inside the screw cylinder portion 51 b and an operation member 58 screwed into the screw hole 57. A screw groove having a large lead angle is formed on the inner peripheral surface of the screw hole 57. The operation member 58 is formed in a cylindrical shape, and an operation portion 58a that is rotationally driven by an electric tool is provided at the right end portion of the operation member 58. Since a thread groove having a large lead angle is formed on the inner peripheral surface of the screw hole 57, the operation member 58 smoothly and integrally follows the pressure member 53 in response to a change in hydraulic pressure in the oil chamber 49. And can move in the left-right direction with respect to the tubular member 51.

Next, the characteristics of the gas spring 11 will be described.
FIG. 5 is a diagram showing the correlation among the compressed gas pressure of the compressed gas of the gas spring 11, the spring force (biasing force), and the retracted state (stroke state) of the rod member 23. The “free state” indicates a free length state in which the rod member 23 has advanced to the maximum as shown in FIG. The “half stroke state” indicates a state where the rod member 23 is retracted by a half stroke as shown in FIG. The “maximum stroke state” indicates a state in which the rod member 23 is retracted to the maximum as shown in FIG.

  For example, in the case of the gas spring 11 of the present embodiment, when the filling gas pressure of the most compressed gas is 10 MPa, the spring force is about 2700 Kgf in the free length state where the object 9 is not suspended. In the maximum stroke state in which the heavy object 9 is suspended and the rod member 23 is retracted to the maximum, the spring force is about 4500 kgf.

  Here, in the half stroke state in which the object 9 having a weight of about 3700 kg is suspended from the balancer 10, the length of the balancer 10 can be adjusted within a range of ± 50 mmST (the height position of the object can be adjusted). In this case, in order to move the object 9 up and down by, for example, 5 mmST, a force of about 90 Kgf must be applied manually, so it is difficult to manually adjust the height position of the object 9. Therefore, in the balancer 10 of the present application, the variable space 40 is equipped with the adjusting mechanism 45, and the height position of the object 9 is easily adjusted by using the oil pressure.

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 first suspension piece 41 of the balancer 10 to be suspended on the overhead crane 1, the lower hook 7 is engaged with the second suspension piece 42, and the balancer 10 is It is interposed between the upper and lower hooks 6 and 7. When the object 9 is not suspended by the overhead crane 1, the rod member 23 is advanced from the main body case 12 to the maximum by the urging force of the compressed gas filled in the gas working chamber 27. At this time, the balancer 10 is in a state in which the frame 30 is contracted to the maximum by the gas spring 11.

  When the object 9 is suspended by the overhead crane 1, the object 9 is suspended via the balancer 10, and the weight of the object 9 acts on the second frame 32. Since the first frame 31 is supported by the overhead crane 1, the second frame 32 is lowered, the rod member 23 is moved back into the main body case 12, and the compressed gas in the gas working chamber 27 is moved. Is automatically adjusted so that the urging force of the compressed gas is equal to the weight of the object 9. In this balanced state (see FIG. 3), the weight of the object 9 is apparently zero.

  In this balanced state, in the hydraulic cylinder 46 of the adjustment mechanism 45, the stroke between the first frame 31 and the second frame 32 is the same as the stroke of the rod member 23 retracted into the main body case 12 of the gas spring 11. Since the length of the variable space 40 increases, the rod member 48 advances from the cylinder body 47. Then, although the volume of the oil chamber 49 in the hydraulic cylinder 46 increases, the volume of the oil in the hydraulic cylinder 46 and the pump hole 52 is constant and does not expand or contract. Therefore, the pressurizing member in the cylinder portion 51a. 53 automatically moves to the oil chamber 49 side.

  That is, when the variable space 40 increases and the rod member 48 moves forward from the cylinder body 47, the operation member 58 smoothly rotates along the screw groove having a large lead angle and moves to the oil chamber 49 side. The 49 volume increase is supplemented by the volume decrease of the pump hole 52. Therefore, unless the height position of the object 9 is adjusted, no hydraulic pressure is generated in the hydraulic cylinder 46.

  Here, when adjusting the height position of the object 9, it is necessary to adjust the length of the variable space 40 between the first frame body 31 and the second frame body 32 via the adjustment mechanism 45. There is. By operating the operation member 58 by engaging a manual tool or an electric tool with the operation unit 58a, the pressurizing member 53 is driven to advance or retract, and the hydraulic pressure in the pump hole 52 is increased or decreased. The oil pressure in the oil chamber 49 communicating with the pump hole 52 can be increased or decreased, and the rod member 48 can be advanced or retracted.

  As described above, when the height position of the object 9 is adjusted, the rod member 48 is driven by hydraulic pressure by driving the pressurizing member 53, and the variable space between the third and fourth plate members 35 and 36 is driven. The length of 40 will be adjusted. For example, when the height position of the object 9 is adjusted downward, the oil chamber 49 in the hydraulic cylinder 46 is moved by rotating the operation member 58 and moving the pressure member 53 to the left in FIGS. Therefore, the rod member 48 of the hydraulic cylinder 46 moves to the advance side, the length of the variable space 40 increases, and the height position of the object 9 can be adjusted downward.

  When the length of the variable space 40 increases, the rod member 23 of the gas spring 11 moves back and forth, and the gas pressure of the compressed gas increases. The hydraulic cylinder 46 generates an oil pressure that cancels the increase in the spring force due to the increase in the gas pressure.

  Contrary to the above, for example, when the height position of the object 9 is adjusted upward, the operating member 58 is rotated to move the pressure member 53 to the right in FIGS. Since the hydraulic pressure in the oil chamber 49 in 46 decreases and becomes negative, the rod member 48 of the hydraulic cylinder 46 moves to the retracting side, the length of the variable space 40 decreases, and the height position of the object 9 Can be adjusted upward.

The adjusting mechanism 45 is configured to supply the hydraulic pressure generated by the pump mechanism 50 to the hydraulic cylinder 46 and adjust the length of the variable space 40 using the hydraulic pressure. Therefore, since a large hydraulic pressure can be generated by the adjusting mechanism 45, the height position of the heavy object 9 of several tons can be adjusted easily and quickly with a small amount of labor, and the work efficiency can be improved. Can do.
Moreover, the adjusting mechanism 45 has a simple configuration and can be manufactured at low cost.

  Since this gas spring 11 is a push-type gas spring 11 that urges the rod member 23 in the direction of advancing from the main body case 12 by compressed gas, it is possible to reduce the number of seal locations around the gas working chamber 27, Leakage of compressed gas filled and sealed in the working chamber 27 can be reduced, and maintenance costs such as filling of compressed gas can be reduced.

Next, the gas spring type balancer 10A will be described with reference to the drawings. However, the same components as those in the first embodiment are denoted by the same reference numerals, and only different components will be described.
As shown in FIGS. 6 and 7, the gas spring type balancer 10A includes a pull type gas spring 61, a case member 62, a first suspension piece 41, a second suspension piece 42, and an adjustment mechanism 45A. Have

First, the pull type gas spring 61 will be described.
The pull type gas spring 61 has a cylinder hole 67, a rod member 70, and a gas working chamber 75. The rod member 70 is urged in the direction of retreating into the cylinder hole 67 by the compressed gas filled in the gas working chamber 75.

  The body case 68 that forms the cylinder hole 67 is fitted into the cylindrical member 64 and is strongly bonded to the cylindrical member 64 with, for example, an adhesive. An annular locking portion 68 a that locks the piston portion 72 when the rod member 70 reaches the upper limit position is formed at the upper end portion of the main body case 68.

  The rod member 70 includes a piston part 72, an extension part 73, and a rod part 74. An annular seal member 72 a is attached to the piston portion 72. The extension portion 73 that continues upward from the piston portion 72 extends upward through the locking portion 68a. The rod portion 74 extends outside the cylinder hole 67 through the rod side end wall portion 80 and the lower lid member 66. The lower end portion of the rod portion 74 is formed to have a small diameter with the stepped portion as a boundary, and the second suspension piece 42 is fixed to the tip portion thereof.

  The gas working chamber 75 is partitioned in the cylinder hole 67, and the gas working chamber 75 is filled with compressed gas by a gas filling valve 78 mounted in the gas filling hole 77. It is desirable to store a small amount of lubricating oil for sealing so that the compressed gas does not leak at the lower end portion in the gas working chamber 75.

  The rod-side end wall portion 80 is internally fitted and fixed to the main body case 68 via a C-shaped ring member 81. An annular seal member 82a that seals the gap between the main body case 68 and the main body case 68 is attached to the outer peripheral surface, and an annular seal member that seals the sliding gap between the rod portion 74 and the gas tightly is attached to the inner peripheral surface. A seal member 82b is attached. A rod guide ring 84 and a dust seal 85 are attached below the annular seal member 82b.

  The case member 62 includes a cylindrical member 64, and an upper lid member 65 and a lower lid member 66 that block the upper and lower portions of the cylindrical member 64, respectively. A breathing hole 64 a that opens the inside of the cylindrical member 64 to the atmosphere is provided in the upper part of the cylindrical member 64. A variable space 40A having a variable length is formed between the upper lid member 65 and the extension 73. The bolt portion of the first suspension piece 41 is screwed into the shaft center portion of the upper lid member 65. A through hole 69 is formed in the center side portion of the lower lid member 66, and the rod member 70 is inserted so as to be movable in the vertical direction.

Next, the adjustment mechanism 45A capable of adjusting the height position of the object will be described.
The adjustment mechanism 45A is mounted in the variable space 40A, the cylinder body 47 of the hydraulic cylinder 46 is fixed to the upper lid member 65, and the rod member 48 is connected to the extension 73. The cylindrical member 51 passes through the cylindrical member 64 and is fixed to the hydraulic cylinder 46 in a horizontal posture. The upper lid member 65 corresponds to a “first member”, and the extension 73 corresponds to a “second member”. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

Next, the operation and effect of the gas spring type balancer 10A will be described.
In a state where the balancer 10A is interposed between the upper and lower hooks 6 and 7 of the overhead crane 1 and the object 9 is not suspended by the overhead crane 1, the rod is generated by the urging force of the compressed gas filled in the gas working chamber 75. The member 70 is fully retracted into the main body case 62 (see FIG. 6).

  When the object 9 is suspended by the second suspension piece, the rod member 70 is lowered, the rod member 70 is immediately advanced from the main body case 68, and the gas pressure of the compressed gas in the gas working chamber 75 is automatically adjusted. Thus, the urging force by the compressed gas is equal to the weight of the object 9. In this balanced state (see FIG. 7), the weight of the object 9 is apparently zero.

In this balanced state, by adjusting the variable space 40A by the adjusting mechanism 45A in the same manner as in the first embodiment, the height position of the heavy object 9 can be easily and quickly adjusted with little effort.
Since this gas spring 11A is a pull type that urges the rod member 70 in a direction to retract the main body case 68, the structure of the balancer can be simplified and reduced in size, and can be manufactured at low cost. Except for this, the same operations and effects as those of the first embodiment can be obtained.

Next, a modified example in which the embodiment is partially modified will be described.
1) 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.
2) In the first and second embodiments, the gas springs 11 and 11A may be mounted upside down in the illustrated state.
3) In the first and second embodiments, the adjusting mechanisms 45 and 45A are not limited to the hydraulic cylinder 46, and may be configured by a hydraulic jack, an electric jack, a screw jack, an air cylinder, or the like.

4) In the first embodiment, instead of the frame body 30 having four tie rods 37 and 38, the frame body 30 may be configured by a pair of tie rods.
5) In addition, various modifications can be made to the above-described embodiment without departing from the spirit of the present invention.

1 is a schematic overall view of a gas spring type balancer according to a first embodiment of the present invention. It is a longitudinal cross-sectional view in the free length state of a gas spring type balancer. It is a longitudinal cross-sectional view in the half stroke state (balance state) of a gas spring type balancer. It is a longitudinal cross-sectional view in the maximum stroke state of a gas spring type balancer. It is a diagram which shows the gas spring force with respect to the change of the stroke of a rod member. It is a longitudinal cross-sectional view in the free-length state of the gas spring type balancer which concerns on Example 2 of this invention. It is a longitudinal cross-sectional view in the half stroke state (balance state) of a gas spring type balancer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Overhead crane 9 Object 10, 10A gas spring type balancer 11 Push type gas spring 12 Main body case 23 Rod member 27 Gas working chamber 30 Frame body 31 First frame body 32 Second frame body 40, 40A Variable space 41 First Suspension piece 42 Second suspension piece 45, 45A Adjustment mechanism 46 Hydraulic cylinder 50 Pump mechanism 61 Pull type gas spring

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 first member coupled to a suspension portion of the suspension means;
A second member connected to the first member via the gas spring and connected to the object to be suspended, wherein the first member is provided with a variable space that expands as the weight of the object to be suspended increases. A second member facing one member;
An adjusting mechanism having a hydraulic cylinder disposed in the variable space and operatively connected to the first and second members and a pump mechanism for adjusting the hydraulic pressure of the hydraulic cylinder;
A gas spring type balancer characterized in that the height position of a suspended object can be adjusted by adjusting the hydraulic pressure of the hydraulic cylinder by the pump mechanism of the adjusting mechanism.   The gas spring balancer according to claim 1, wherein the hydraulic cylinder includes a cylinder body fixed to the first member and a rod member connected to the second member.   2. The gas spring balancer according to claim 1, wherein the hydraulic cylinder includes a cylinder main body fixed to the second member and a rod member connected to the first member.   The pump mechanism is fixed to a cylinder body of the hydraulic cylinder and forms a pump hole communicating with an oil chamber of the hydraulic cylinder, and the pump mechanism is attached to the cylindrical member and can pressurize oil in the pump hole. The gas spring type balancer according to any one of claims 1 to 3, further comprising a pressure member and a pressure member driving mechanism capable of driving the pressure member.   The pressurizing member driving mechanism includes a screw hole formed in the cylindrical member and having a large lead angle screw groove formed on an inner peripheral surface thereof, and an operation member screwed into the screw hole. The gas spring type balancer according to claim 4. 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,
6. The gas spring type balancer according to claim 5, wherein the gas spring type balancer is a pull type gas spring that urges the rod member in a direction in which the rod member is retracted into the main body case by compressed gas. The gas spring has a main body case, a rod portion that is attached to the main body case and extends through the rod side end wall portion of the main body case, and a gas working chamber defined in the main body case,
6. The gas spring type balancer according to claim 5, 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.