JP5771086B2 - Hydraulic jack - Google Patents

Description

  The present invention relates to a hydraulic jack for inserting and removing an upper rod with respect to a lower rod.

  The hydraulic jack disclosed in Patent Document 1 communicates the back pressure chamber of the lower piston and the positive pressure chamber of the upper piston, and the expansion and contraction is performed as follows. That is, when extending the hydraulic jack, pressure oil is supplied to the positive pressure chamber of the lowest piston. As a result, the lowest piston rises, and pressure oil is supplied to the positive pressure chamber of the upper piston as the volume of the back pressure chamber of the piston decreases, thereby raising the upper piston. In the same manner, the other pistons are also raised, thereby extending the hydraulic jack. Further, by releasing the pressure in the positive pressure chamber of the lowest piston, each piston descends, and thereby the hydraulic jack contracts.

JP 2004-218734 A

  By the way, when the hydraulic jack is extended and contracted, there is a possibility that the operating oil may be ejected from between the lower piston and the upper piston inserted therein, and the surroundings may become dirty.

  Further, in Patent Document 1, in order to prevent pressure accumulation from occurring between the dust seal provided between the upper piston and the lower piston and the oil seal below this, the working oil may be ejected. A technique for incising part of the direction is disclosed. However, it is not possible to completely prevent the pressure accumulation just by cutting a part in the circumferential direction of the dust seal, and there is a concern that hydraulic oil may be ejected from the cut portion of the dust seal, and hydraulic oil is ejected. There are still challenges.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the hydraulic jack which can suppress the ejection of hydraulic fluid appropriately.

In order to solve the above-mentioned problem, the hydraulic jack of the present invention is a hydraulic jack in which the upper rod is taken in and out of the lower rod by changing the amount of hydraulic oil supplied to the lower rod. A notch for oil sump recessed outward is formed over the upper edge of the inner peripheral surface of the lower rod, and a part of the oil reservoir notch in the circumferential direction is formed on the upper end of the lower rod. A communication path that communicates with the outer peripheral surface of the slab is provided .

  Further, it is preferable that a guide groove extending in the vertical direction is formed on the outer peripheral surface of the upper end portion of the lower rod, and the upper end portion of the guide groove is communicated with the communication path.

  In the present invention, it is possible to appropriately prevent the hydraulic oil from being ejected from between the upper rod and the lower rod.

It is sectional drawing which shows the principal part of the movable rod in the hydraulic jack of this embodiment. It is a perspective view which shows the elevator apparatus which provided the hydraulic jack. It is a front view which shows a jack main body. It is explanatory drawing which showed the internal structure of the jack main body typically. It is sectional drawing which shows the principal part of a fixed rod.

  Hereinafter, the present invention will be described with reference to the accompanying drawings. As shown in FIG. 2, the hydraulic jack 1 of this embodiment is used as drive means for an elevator apparatus. The jack main body 2, a tank 3 for storing hydraulic oil, and the hydraulic oil in the tank 3 are used as jack main body. 2 is provided with a pump (not shown). The pump is incorporated in a vertically long hydraulic unit 4 installed side by side with the jack body 2 on the bottom of the elevator chamber 32. The tank 3 is provided at the upper end of the hydraulic unit 4.

  In addition to the hydraulic jack 1, the elevator apparatus includes a platform 29 connected to the upper end of the uppermost rod 5 of the jack body 2, and an elevator car 30 supported by the platform 29. The platform 29 moves up and down by expanding and contracting the jack body 2, and thereby the elevator car 30 moves up and down. Reference numeral 31 in FIG. 2 is a guide rail that guides the elevator car 30 to move up and down, and is provided in a state where two are erected on the bottom of the elevator chamber 32 so as to be positioned on both sides of the jack body 2.

  As shown in FIG. 3, the jack body 2 is a multistage type, and has a plurality of rods 5, and each rod 5 excluding the lowermost rod 5 is inserted into and removed from the lower rod 5. . The lowermost rod 5 constitutes a fixed rod 6 fixed to the installation surface, and the other rods 5 constitute a movable rod 7 that moves up and down relative to the lower rod 5. The jack body 2 of the present embodiment has three movable rods 7 and has a total of four rods 5.

  FIG. 4 is an explanatory view schematically showing the internal structure of the jack body 2. As shown in the drawing, each rod 5 except for the uppermost rod 5 (hereinafter referred to as the uppermost rod 13) has a cylindrical portion 8 that is long in the vertical direction.

  An enormous piston portion 9 is formed at the lower end of each movable rod 7. In addition, each movable rod 7 excluding the uppermost rod 13 has the lower end of the cylinder portion 8 closed by the piston portion 9.

  The piston portion 9 of each movable rod 7 is accommodated in the cylinder portion 8 of the lower rod 5 so as to be slidable in the vertical direction. The inside of the cylinder portion 8 of each rod 5 excluding the uppermost rod 13 is divided into a first oil chamber 10 located below the piston portion 9 by the piston portion 9, and the upper movable rod 7 above the piston portion 9. It is partitioned into a second oil chamber 11 located around the cylinder portion 8.

  A port 12 communicating with the first oil chamber 10 of the fixed rod 6 is formed at the lower end of the cylinder portion 8 of the fixed rod 6. The port 12 communicates with the tank 3 through a hose (not shown). Thereby, the hydraulic oil in the tank 3 can be supplied to the first oil chamber 10 of the fixed rod 6, and the hydraulic oil in the first oil chamber 10 of the fixed rod 6 can be discharged to the tank 3.

  A communication hole 14 is formed at the lower end of the cylinder portion 8 of each movable rod 7 excluding the uppermost rod 13. The first oil chamber 10 of each movable rod 7 excluding the uppermost rod 13 communicates with the second oil chamber 11 of the lower rod 5 through the communication hole 14. Hydraulic oil is sealed in the first oil chamber 10 and the second oil chamber 11 of each movable rod 7 excluding the uppermost rod 13 and the second oil chamber 11 of the fixed rod 6. Further, a small hole 15 that allows the second oil chamber 11 of the lower rod 5 to communicate with the first oil chamber 10 of the rod 5 is formed in the piston portion 9 of the uppermost rod 13.

  In order to extend the jack body 2, the pump is driven to supply the hydraulic oil in the tank 3 to the first oil chamber 10 of the fixed rod 6, and the piston portion of the upper movable rod 7 disposed in the fixed rod 6. 9 is raised. As a result, the volume of the second oil chamber 11 of the fixed rod 6 is reduced, and the hydraulic oil in the second oil chamber 11 is supplied to the first oil chamber 10 of the upper movable rod 7 through the communication hole 14. Then, the piston portion 9 of the movable rod 7 rises. Similarly, the piston portions 9 of the other movable rods 7 are also raised. In this way, each movable rod 7 protrudes upward from the lower rod 5, thereby extending the jack body 2. When the jack body 2 is extended, the hydraulic oil in the second oil chamber 11 of the movable rod 7 in the second stage from the top flows into the first oil chamber 10 of the movable rod 7 through the small hole 15. The volume of the second oil chamber 11 decreases in the same manner as the other second oil chambers 11.

  In order to contract the jack body 2, the pump motor rotates in the reverse direction to the extension, and the hydraulic oil in the first oil chamber 10 of the fixed rod 6 is discharged to the tank 3 through the port 12, thereby The piston portion 9 of the upper movable rod 7 disposed in the fixed rod 6 is lowered. As a result, the volume of the second oil chamber 11 of the fixed rod 6 is increased, and hydraulic oil is supplied to the second oil chamber 11 from the first oil chamber 10 of the upper movable rod 7. The volume of the single oil chamber 10 is reduced and the movable rod 7 is lowered. Similarly, the piston portions 9 of the other movable rods 7 are also lowered.

  The extension amount of the jack body 2 can be adjusted by changing the amount of hydraulic oil supplied from the tank 3 to the first oil chamber 10 of the fixed rod 6 by controlling the driving of the pump. That is, if the amount of hydraulic oil supplied to the first oil chamber 10 of the fixed rod 6 is adjusted, the second oil chamber of the lower rod 5 is added to the first oil chamber 10 of each movable rod 7 excluding the uppermost rod 13. 11 can adjust the amount of hydraulic oil supplied from the cylinder 11, and thereby the extension amount of the jack body 2 can be adjusted.

  The second oil chamber 11 of the second movable rod 7 from the top can be omitted. In this case, the small hole 15 is not provided in the uppermost rod 13.

  As shown in FIG. 3, the upper end portion of the cylinder portion 8 of the rod 5 excluding the uppermost rod 13 is a massive portion 16 whose outer diameter is larger than the lower portion, and the lower surface of the outer peripheral end portion of each massive portion 16. Has a tapered surface 39 that gradually slopes downward toward the inner periphery.

  As shown in FIG. 1, a through hole 40 (see FIG. 1 and the like) for passing the upper rod 5 is formed inside each enormous portion 16. On the inner peripheral surface constituting the through hole 40 of each enormous portion 16, three grooves 17 extending in the circumferential direction are formed in the vertical direction. In these groove portions 17, a dust seal 18, a packing 19, and a wear ring 21 are sequentially provided from the upper groove portion 17. The dust seal 18 suppresses entry of dust and dirt from the gap 23 formed between the rod 5 provided with the dust seal 18 and the movable rod 7 on the inner side. The packing 19 prevents the hydraulic oil inside the rod 5 from leaking from the gap 23. The wear ring 21 defines the center position of the inner movable rod 7 with respect to the rod 5 provided with the wear ring 21. Reference numeral 20 in FIG. 1 denotes buffering for buffering the pressure inside the rod 5.

  As shown in FIGS. 1 and 5, the previously described hydraulic jack 1 has an oil reservoir notch 22 formed at the upper end of each rod 5 excluding the uppermost rod 13. Each oil reservoir notch 22 is formed on the upper edge of the inner peripheral surface of the upper end portion of the cylinder portion 8 over the entire length in the circumferential direction, and is recessed toward the outside of the rod 5.

  Each oil reservoir cutout portion 22 is formed in an annular shape in plan view, and opens upward from the upper end surface of the cylinder portion 8. Each oil reservoir notch 22 is formed between the cylinder portion 8 of the rod 5 provided with the oil reservoir notch 22 and the cylinder portion 8 of the upper movable rod 7 located inside the oil reservoir notch 22. It leads to the gap 23.

  As the hydraulic jack 1 expands and contracts, the hydraulic oil in the second oil chamber 11 of the lower rod 5 adheres to the outer peripheral surface of each movable rod 7. Further, as described above, even when the second oil chamber 11 of the movable rod 7 in the second stage from the top is omitted, the hydraulic oil adhered to the inner surface of the cylinder portion 8 of the movable rod 7 is the outer periphery of the uppermost rod 13. May adhere to the surface. The hydraulic oil adhering to the outer peripheral surface of each movable rod 7 flows down along the outer peripheral surface of the rod 5 with the rod 5 protruding from the lower rod 5, and the oil reservoir notch 22 of the lower rod 5. It is supposed to accumulate in. Further, the hydraulic oil adhering to the outer peripheral surface of the movable rod 7 is accumulated in the oil reservoir notch 22 of the lower rod 5 even when the rod 5 is inserted into the lower rod 5. . The hydraulic oil stored in the oil reservoir notch 22 in this way closes the gap 23 formed between the cylinder portion 8 of the lower rod 5 and the cylinder portion 8 of the upper rod 5.

  As shown in FIGS. 1 and 5, a peripheral wall portion 24 constituting an outer peripheral surface of the oil reservoir cutout portion 22 protrudes upward from the upper end portion of each rod 5 except the uppermost rod 13. The outer peripheral surface of each peripheral wall portion 24 is flush with and continuous with the outer peripheral surface of the enormous portion 16 below.

  As shown in FIG. 1, an inner oil reservoir notch 22 is provided on the outer periphery of the rod 5 at a part in the circumferential direction of the peripheral wall 24 of each movable rod 7 excluding the uppermost rod 13 or at a plurality of locations in the circumferential direction. A communication path 26 communicating with the surface is formed. For this reason, a part of the hydraulic oil collected in the oil reservoir notch 22 overflows from the upper side of the oil reservoir notch 22 before the rod 5 provided with the communication passage 26 via the communication passage 26. It flows out to the outer peripheral side.

  Each communication passage 26 includes a lateral hole 25 positioned inside the peripheral wall portion 24 and a notch portion 28 positioned outside the peripheral wall portion 24 and opened upward.

  The horizontal hole 25 is located above the bottom surface of the oil reservoir notch 22, and hydraulic oil is accumulated in the oil reservoir notch 22 up to the level of the horizontal hole 25. A two-dot chain line indicated by a <b> 1 in FIG. 1 represents the level of the hydraulic oil stored in the oil reservoir cutout 22. The notch 28 opens from a part of the outer peripheral surface of the peripheral wall 24 in the circumferential direction.

  As shown in FIG. 1, a guide groove 38 whose upper end communicates with the cutout portion 28 of the communication path 26 is formed on the outer peripheral surface of the enormous portion 16 of each movable rod 7 excluding the uppermost rod 13. The guide groove 38 is a vertical groove extending in the vertical direction.

  The upper end portion of the guide groove 38 communicates with the inner oil reservoir cutout portion 22 through the communication passage 26. The lower end of the guide groove 38 opens downward from the tapered surface 39 of the enormous portion 16. For this reason, a part of the hydraulic oil stored in the oil reservoir notch 22 is supplied to the guide groove 38 via the communication path 26. The hydraulic oil that has flowed into the guide groove 38 flows down along the inner surface of the guide groove 38 as indicated by the arrow in FIG. 1, and is then discharged from the lower end of the guide groove 38 to the tapered surface 39 side of the enormous portion 16. The Further, the hydraulic oil discharged to the tapered surface 39 in this way flows down along the tapered surface 39 to reach the outer peripheral surface of the cylinder portion 8 below the enormous portion 16, and along the outer peripheral surface of the cylinder portion 8. It flows down to the oil reservoir notch 22 of the lower rod 5. That is, the hydraulic oil stored in the oil reservoir cutout portions 22 of the movable rods 7 excluding the uppermost rod 13 is supplied to the oil reservoir cutout portions 22 of the lower rod 7 through the communication passages 26 and the guide grooves 38. Is done.

  As shown in FIG. 5, a tubular pipe connector 33 is provided on a part of the peripheral wall 24 of the fixed rod 6 in the circumferential direction. A pipe connection part 35 is formed at the end of the pipe connector 33 opposite to the oil reservoir cutout part 22. The pipe connecting portion 35 protrudes toward the outside of the fixed rod 6.

  One end of a connecting pipe 36 represented by a chain line in FIG. 5 is connected to the pipe connecting portion 35. Although not shown, the other end of the connection pipe 36 is connected to the tank 3. Thereby, a part of the hydraulic oil collected in the oil reservoir notch 22 of the fixed rod 6 can be supplied to the tank 3 through the pipe connector 33 and the connection pipe 36 in this order.

  The hole 37 for flowing the hydraulic oil formed inside the tubular pipe connector 33 is located above the bottom surface of the oil reservoir notch 22 of the fixed rod 6. For this reason, the hydraulic oil is accumulated in the oil reservoir notch 22 up to the level of the hole 37. A two-dot chain line indicated by a <b> 2 in FIG. 5 represents the liquid level of the hydraulic oil stored in the oil reservoir notch 22.

  The hydraulic jack 1 of the present embodiment described above is configured to move the upper rod 5 in and out of the lower rod 5 by changing the amount of hydraulic oil supplied into the lower rod 5. And it has the structure that the notch part 22 for oil reservoirs dented outside is formed over the upper edge of the internal peripheral surface of the said rod 5 of the lower step. Therefore, the hydraulic oil adhering to the outer peripheral surface of the upper rod 5 is accumulated in the oil reservoir cutout 22 of the lower rod 5, and the cylinder portion 8 of the lower rod 5 and the cylinder portion of the upper rod 5 are collected by this hydraulic oil. 8 can be closed. Therefore, when the hydraulic jack 1 is extended or contracted, the hydraulic oil accumulated in the oil reservoir notch 22 can suppress the hydraulic oil inside the rod 5 from being ejected upward from the gap 23. The area around 1 is difficult to get dirty.

  In the present embodiment, a communication passage 26 is provided at the upper end of the movable rod 7 so that a part of the circumferential direction of the oil reservoir notch 22 is communicated with the outer peripheral surface of the movable rod 7. If the communication passage 26 is not provided, the hydraulic oil accumulated in the oil reservoir notch 22 overflows from above the oil reservoir notch 22 and adheres to a wide range of the upper end surface and the outer peripheral surface of the movable rod 7. It will be. Then, the hydraulic oil that spreads and adheres in this way may be scattered around due to vibration generated when the hydraulic jack 1 expands and contracts. However, in the present embodiment, by providing the communication passage 26, a part of the hydraulic oil accumulated in the oil reservoir notch 22 can be collected from the communication passage 26 and discharged to the outer peripheral surface of the rod 5. For this reason, it can suppress that hydraulic fluid spreads and adheres to the upper end surface and outer peripheral surface of the rod 5, and can suppress further that hydraulic fluid scatters to circumference | surroundings.

  In the present embodiment, a guide groove 38 extending in the vertical direction is formed on the outer peripheral surface of the upper end portion of the movable rod 7, and the upper end portion of the guide groove 38 communicates with the communication path 26. With this configuration, the hydraulic oil discharged from the oil reservoir notch 22 through the communication path 26 to the outer peripheral surface of the rod 5 can be flowed together in a streak shape by the guide groove 38. Therefore, it is possible to further suppress the hydraulic oil flowing down the outer peripheral surface of the upper end portion of the movable rod 7 from being scattered around due to vibration of the movable rod 7 or the like. Further, the hydraulic oil in the oil reservoir notch 22 can be supplied to the outer peripheral surface of the rod 5 below the guide groove 38 to improve the sliding of the rod 5.

  The number of rods 5 included in the jack body 2 is not limited to four, and may be two or more. In addition, the shape of the communication path 26 is not limited to that of the present embodiment, and may be configured with only holes or notches. Moreover, in this embodiment, although the guide groove 38 was formed to the lower end of the outer peripheral surface of the enormous part 16, it is not limited to this. For example, the guide groove 38 may be extended to the tapered surface 39 side to be formed up to the inner peripheral edge of the tapered surface 39. Can lead. Moreover, although the example which used the hydraulic jack 1 for the elevator apparatus was demonstrated above, it is not limited to this, You may use for another apparatus.

DESCRIPTION OF SYMBOLS 1 Hydraulic jack 5 Rod 22 Notch part for oil sump 26 Communication path 38 Guide groove

Claims (2)

By changing the amount of hydraulic oil supplied to the inside of the lower rod, it is a hydraulic jack that takes the upper rod into and out of the lower rod, over the upper edge of the inner peripheral surface of the lower rod, A notch for oil sump recessed outward is formed, and a communication passage is provided at the upper end of the lower rod to allow a part of the circumferential direction of the oil summit notch to communicate with the outer peripheral surface of the lower rod. Hydraulic jack characterized by. 2. The hydraulic jack according to claim 1, wherein a guide groove extending in a vertical direction is formed on an outer peripheral surface of an upper end portion of the lower rod, and an upper end portion of the guide groove is communicated with the communication path .

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