JP2006131383A - Lifting carriage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lifting carriage in which hydraulic piping can be installed. <P>SOLUTION: The lifting carriage 1 is provided with a fork 4 which turns around a rotating vertical shaft 3, a hydraulic oil route 6 for supplying hydraulic oil to a hydraulic cylinder H, and an oil pressure generating unit 7 connected to the hydraulic oil route 6. The hydraulic oil route 6 is provided with fixed oil passages 8 and 9 for supplying hydraulic oil to both shaft ends 30 and 31 of the vertical shaft 3 which are directed upward and downward, shaft-inside oil passages 12 and 13 extended from both the shaft ends 30 and 31 of the vertical shaft 3 on the way in the axial direction expressed by an arrow Z and opened in openings 10 and 11 at the peripheral surface on the way in the axial direction, swivel connectors 15 and 15 for connecting the fixed oil passages 8 and 9 to the shaft-inside oil passages 12 and 13 of the vertical shaft 3, and movable oil passages 16 and 17 connected to the openings 10 and 11 of the shaft-inside oil passages 12 and 13 at one end thereof and connected to the hydraulic cylinder H at the other end thereof. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a lifting carriage for a three-way stacking truck that operates in a warehouse or factory.

The following Patent Documents 1 and 2 disclose a conventional technique in which a horizontal body (sheath) is provided so as to be movable back and forth with respect to a fork such as a forklift, and the horizontal body is moved back and forth by a drive source. FIG.
The three-direction stacking track V shown in FIG. 2 is swung in the direction indicated by the arrow Y so that the two forks 4 are lateral to the lifting carriage C by the lifting carriage C supported by the mast M so as to be movable up and down. (Rotate). The lifting carriage C has two forks 4
Can be moved (shifted) in the vehicle width direction indicated by the arrow W.
Japanese Utility Model Publication No. 5-42298 Japanese Utility Model Publication No. 63-45797

When using a forklift or the like to carry out cargo handling work between rack racks facing each other, it is desirable that the fork is long in order to pick up luggage from the back of the rack shelf. ), The fork turning radius must be as small as possible. From such a demand, it is conceivable to apply the above-described conventional technique to the three-way stacking track V.

However, the following problems arise. That is, if the drive source is a hydraulic cylinder, a hydraulic pipe for supplying hydraulic pressure to the hydraulic cylinder from a hydraulic pump that is not shown in the drawing built in the lifting carriage C may be exposed to the outside of the lifting carriage C. Do not avoid. For this reason, there is a risk that the hydraulic pipe may be inadvertently caught on a load or the like during the operation of the lifting carriage C. Further, since the large bending and deformation of the hydraulic piping accompanying the operation of the lifting carriage C are frequently repeated, for example, when a rubber hose is applied as the hydraulic piping, there is a problem that this life becomes extremely short.

Furthermore, the portion of the hydraulic piping exposed from the lift carriage C needs to be loosened to some extent and bend gently so that the hydraulic piping can be freely bent or deformed. The hydraulic piping exposed in such a slack state may obstruct the view of the operator who gets into the driver seat at the rear of the mast M.

In view of the above-described problems, an object of the present invention is to provide an elevating carriage that can incorporate hydraulic piping.

An elevating carriage according to the present invention includes an elevating carriage having a rotating upright shaft and a fork revolving around the erecting shaft, and an advancing / retracting member capable of supporting a pallet is attached to the fork so as to freely advance and retract. Hydraulic pressure is supplied to a hydraulic cylinder that moves forward and backward through a hydraulic path that passes through the upright shaft.

Further, in the elevating carriage according to the present invention, the fork has a rear end connected to the upright shaft and a tip extends horizontally from the upright shaft, and the hydraulic cylinder projects the advance / retreat member from the front end of the fork. Or an actuating rod that is retracted toward the rear end of the fork.

Furthermore, the elevating carriage according to the present invention includes two forks and two hydraulic cylinders, and the hydraulic cylinder is provided for each fork.

Further, in the lifting carriage according to the present invention, the hydraulic path extends from the shaft end of the upright shaft to the middle in the axial direction, and the hydraulic path extends halfway in the axial direction. An in-shaft oil passage having an opening in the peripheral surface, a swivel fitting that connects the fixed oil passage to the shaft end of the upright shaft, one end connected to the opening of the in-shaft oil passage, and the other end to the hydraulic cylinder And a movable oil passage to be connected.

Furthermore, in the lifting carriage according to the present invention, the hydraulic path includes two paths that alternately serve as the feed side or the return side, and one of the two paths is the shaft end of both of the upright shafts. One of the two paths, the other path of the two paths is connected to the other of the two shaft ends, and the upright shaft,
Two axial oil passages each extending from the both shaft ends to the middle in the axial direction are formed on the circumferential surface in the middle of the axial direction, and individual openings are opened, and the hydraulic cylinder advances the operating rod. A feed-side port for introducing hydraulic pressure to be introduced, and a return-side port for introducing hydraulic pressure for retracting the operating rod, each opening of the two in-shaft oil passages being two movable oil passages And connecting to the sending port and the return port, respectively.

Further, in the lifting carriage according to the present invention, the hydraulic path includes two paths that alternately serve as the feeding side or the returning side, and the two paths are connected to one shaft end of the upright shaft, The upright shaft is formed with two in-shaft oil passages that respectively extend from the one shaft end to the middle in the axial direction and open individual openings on the circumferential surface in the middle of the axial direction. A feed-side port for introducing hydraulic pressure for advancing the operating rod; and a return-side port for introducing hydraulic pressure for retracting the actuating rod; each of the two in-shaft oil passages has two openings The movable oil passages are respectively connected to the feed-side port and the return-side port.

The lifting carriage according to the present invention has a structure in which a fork turns around an upright shaft for rotation, such as a three-way stacking track, and the advancing / retracting member that supports the pallet is moved back and forth with respect to the fork by a hydraulic cylinder. Furthermore, the hydraulic pressure provided for the operation of the hydraulic cylinder can be supplied to the hydraulic cylinder through a hydraulic path that passes from the hydraulic pump to the upright shaft, for example. Therefore, according to the raising / lowering carriage, the problems of the prior art can be specifically solved as follows.

That is, according to the lifting carriage according to the present invention, the fixed oil passage that supplies the hydraulic pressure to the shaft end of the upright shaft for rotation is connected to the in-shaft oil passage of the upright shaft via the swivel joint.
The upright shaft can be freely rotated with respect to the fixed oil passage while securely connecting the fixed oil passage, the swivel pipe joint, the in-shaft oil passage, and the movable oil passage constituting the hydraulic passage. In addition, since the hydraulic cylinder coupled to the upright shaft rotates together with the upright shaft, the movable oil passage connecting the opening of the peripheral surface of the upright shaft and the hydraulic cylinder is connected to the upright shaft and the hydraulic cylinder. The movable oil passage is not bent or deformed.

Therefore, for example, a steel pipe having a lower expansion coefficient than that of a rubber hose can be applied as the movable oil path, and thereby, pressure loss in the hydraulic path can be minimized. Alternatively, even when a rubber hose is applied as the movable oil passage, the deterioration does not proceed due to frequent deformation of the rubber hose, so that the frequency and location of maintenance related to the lifting carriage can be reduced.

Further, there are few places where the hydraulic path is exposed to the outside of the elevating carriage, and the hydraulic path does not protrude greatly from the elevating carriage, so there is no possibility that the hydraulic path is caught by luggage or the like during the operation of the elevating carriage. In addition, the hydraulic path hardly enters the field of view of the operator who operates the rear of the lifting carriage. Therefore, the operator can concentrate on the cargo handling work.

Further, according to the elevating carriage according to the present invention, when the operating rod of the hydraulic cylinder moves forward, the advance / retreat member protrudes from the front end of the fork, and when the operating rod of the hydraulic cylinder moves backward, the advance / retreat member becomes the rear end of the fork. Retreat toward. In addition, when the lifting carriage includes two forks and two hydraulic cylinders, each fork is provided with a hydraulic cylinder. For example, when changing the interval between the forks, each fork is combined with each hydraulic cylinder. There is an advantage that it can be moved.

Further, when a double-acting hydraulic cylinder is applied to the lifting carriage according to the present invention, one fixed oil passage is connected to one shaft end of the upright shaft, and the other fixed oil passage is connected to the other shaft end of the upright shaft. Connected to
These can be connected to the feed-side port and the return-side port of the double-acting hydraulic cylinder through two upright shaft oil passages and two movable oil passages, respectively. Therefore, since the operating rod of the hydraulic cylinder can be driven by the compressive force of the hydraulic pressure, even if a large load is applied to the individual advancing / retreating members, the smooth advancing / retreating operation of the operating rod of the hydraulic cylinder can be maintained.

In addition, when two paths that alternately carry the feed side or the return side are connected to one shaft end of the upright shaft, the hydraulic path can be more freely piped to the lifting carriage, and piping work in the manufacturing process Can be realized easily. For example, it may be opened to either one of the shaft ends of the upright shaft. In such a case, the distance for digging the in-shaft oil passage from one shaft end of the upright shaft is shallower than the distance for digging from the other shaft end, so that the manufacturing time and cost can be reduced.

Moreover, rather than piping two hydraulic paths apart from each other inside the lift carriage,
If two hydraulic paths are bundled and piped, the work is completed once, and any of the two hydraulic paths can be passed through a place where an operator can easily work.

A lift carriage according to an embodiment of the present invention will be described with reference to the drawings. In addition, the same reference numerals are given to the components already described as the prior art, and illustration or detailed description thereof will be omitted.

As shown in FIGS. 1 and 2, the elevating carriage 1 includes a rotating upright shaft 3 that is supported by the housing 2 in an upright posture, a fork 4 with an upright portion 41 raised at the rear end 40, and an upright shaft 3. , A finger plate 5 that hangs the rear end 40 of the fork 4 movably in the vehicle width direction of the three-way stacking truck V, a hydraulic cylinder H disposed in the virtual frame A, and a hydraulic path to the hydraulic cylinder H 6 and a hydraulic pressure generating unit 7 for supplying the hydraulic pressure via 6. Details will be described in the following examples.

The hydraulic path 6 is indicated by an arrow Z from the fixed oil passages 8 and 9 for supplying hydraulic pressure to both the shaft ends 30 and 31 facing up and down of the upright shaft 3 and the shaft ends 30 and 31 of the upright shaft 3 respectively. In-shaft oil passages 12, 1 each extending partway in the axial direction and having openings 10 and 11 opened on the circumferential surface in the axial direction.
3 and the swivel fitting 1 that connects the fixed oil passages 8 and 9 to the in-shaft oil passages 12 and 13 of the upright shaft 3, respectively.
4 and 15, and movable oil passages 16 and 17 having one ends connected to the openings 10 and 11 of the in-shaft oil passages 12 and 13 and the other ends connected to the hydraulic cylinders H, respectively.

Here, unless otherwise specified, the term “connection” refers to joining pipes or joints of paths by using a well-known pipe joint or performing welding or the like. Also, swivel fitting 14
, 15 can be 360 ° freely rotating pipe joints. The hydraulic pressure generating unit 7 is
This is a well-known device in which a hydraulic pump, a reservoir tank, a direction control valve, and piping connecting them are integrated.

As shown in FIGS. 2 to 4, the fork 4 includes a sheath-like or bag-like advance / retreat member 43 that extends from the upright shaft 3 in the horizontal direction and covers from the rear end 40 to the tip 42. Although only one fork 4 appears in FIG. 2, another fork is actually hooked on the finger plate 5 at a position overlapping the fork 4 in the drawing. Two advancing / retracting members 43 that respectively cover these two forks 4 are connected to each other via a horizontal member 44 having an L-shaped cross section. The horizontal member 44 is connected to the tip of the operating rod 61 of the hydraulic cylinder H.

The two fixed oil passages 8 and 9 constituting the hydraulic passage 6 are steel pipes that alternately serve as a feed-side or return-side route, respectively. That is, from the hydraulic pressure generating unit 7 to one fixed oil passage 8, the shaft oil passage 12,
When the hydraulic pressure is supplied to the feed port 60 of the hydraulic cylinder H through the movable oil passage 16, the operating rod 61 of the hydraulic cylinder H moves forward in the direction of arrow F, and at the same time, the return port 62 of the hydraulic cylinder H. The hydraulic oil is discharged from the other fixed oil passage 9. On the other hand, from the hydraulic pressure generating unit 7 through the other fixed oil passage 9, the in-shaft oil passage 13, and the movable oil passage 17, the hydraulic cylinder H
When the hydraulic pressure is supplied to the return side port 62, the operating oil is discharged from the feed side port 60 of the hydraulic cylinder H to the one fixed oil passage 8 at the same time as the operating rod 61 moves backward in the arrow R direction. .

According to the lifting carriage 1 described above, when the operating rod 61 of the hydraulic cylinder H moves forward in the direction of arrow F, the horizontal member 44 is pushed out toward the tip 42 of the fork 4 by the operating rod 61. The two advancing / retracting members 43 move forward together with the member 44. Thereby, each advancing / retreating member 43 protrudes from the tip 42 of the fork 4 as shown by the phantom line in FIG.

On the contrary, when the operating rod 61 of the hydraulic cylinder H moves backward in the arrow R direction, the operating rod 61
Since the horizontal member 44 is driven toward the rear end 40 of the fork 4, the horizontal member 4
The two advancing / retracting members 43 together with 4 retract simultaneously. Thereby, each advance / retreat member 43 returns to the position represented by the solid line in FIG.

In this way, the operating rod 61 of the hydraulic cylinder H is directly supplied to the feed port 60 or the return port 62 in the process of moving the two advancing and retracting members 43 forward and backward according to the operating rod 61 of the hydraulic cylinder H. It is driven by the hydraulic compression force. Accordingly, the individual advancing and retracting members 4
Even when a large load is applied to 3, the smooth forward / backward movement of the operating rod 61 of the hydraulic cylinder H can be maintained.

Further, as shown in FIG. 5, one hydraulic cylinder H is provided for each of the two forks 4,
The two forks 4 may be moved forward and backward separately by the two hydraulic cylinders H, respectively. In this case, the fork 4 which is hooked on the finger plate 5 and is movable in the vehicle width direction
When changing the distance between them, there is an advantage that the individual forks 4 can be moved together with the individual hydraulic cylinders H.

Further, if a flow dividing valve not shown in the figure is provided in the path between the opening 10 of the upright shaft 3 and the feed port 60 of each of the two hydraulic cylinders H, the two hydraulic cylinders H Each operation can be synchronized. For the same reason, a flow collecting valve may be provided between the opening 11 and the return ports 62 of the two hydraulic cylinders H. In addition, the individual hydraulic cylinders H may be coupled to the upright shaft 3 via a support not shown in the figure, but the individual hydraulic cylinders H are fixed to the side surfaces of the individual forks 4 as shown in FIG. Then, the operating rod 61 may be connected to the side surface of the advance / retreat member 43.

Next, the three-direction stacking track V will be described. As shown in FIG.
A pair of horizontal rails 102 extending in the vehicle width direction of the truck V are fixed to the upper and lower portions of 01, and a shift gear 103 composed of two rack gears is fixed along the pair of horizontal rails 102, respectively. . A plurality of groove portions 104 are formed in each of the pair of horizontal rails 102. Furthermore, a roller (same reference numeral) is engaged in the plurality of grooves 104, and the lifting carriage 1 is attached via the rollers so as to be movable in the vehicle width direction.

On the other hand, a pair of pinions 105 that respectively mesh with the two shift gears 103 are provided inside the housing 2 of the elevating carriage 1, and the main shaft 10 accommodated in an upright guide rail G is provided.
6 and a first hydraulic motor 107 in which a pinion 125 of an output shaft is engaged with one of a pair of pinions 105 via a gear 115 are housed. The first hydraulic motor 107 is supplied with hydraulic pressure from a hydraulic pressure generating pump or the like not shown in the drawing.

The shift operation of the fork 4 can be performed by starting the first hydraulic motor 107 with a hydraulic pressure generating pump or the like and causing the lifting carriage 1 to travel along the pair of horizontal rails 102 in the vehicle width direction. Further, as shown in FIG. 2, a second hydraulic motor 108 that applies a rotational force to the upright shaft 3 via a gear train 118 is housed inside the housing 2 of the elevating carriage 1. The rotating operation of the fork 4 starts the second hydraulic motor 108 by a hydraulic pressure generating pump or the like to rotate the upright shaft 3, and the finger plate 5 is rotated along with the rotation of the upright shaft 3.
The hydraulic cylinder H and the fork 4 can be swung together.

Further, the guide rail G and the housing 2 are separated from each other, and the housing 2 is guided by the guide rail G so as to be movable up and down. Furthermore, a sprocket 111 is attached to the operating rod of the lift cylinder 110 fixed along the guide rail G.
A chain 112 having one end fixed to the guide rail G and the other end fixed to the housing 2 is wound around. When the sprocket 111 moves up and down in accordance with the expansion and contraction operation of the lift cylinder 110, the housing 2 moves up and down while being guided by the guide rail G.

When the elevating carriage 1 is applied to the three-way stacking track V described above, the fixed oil passages 8 and 9 and the in-shaft oil passages 12 and 13 of the upright shaft 3 are respectively connected via the swivel joints 14 and 15. Since they are connected, the rotation of the upright shaft 3 with respect to the fixed oil passages 8 and 9 is allowed while the connection of the hydraulic passage 6 is ensured, and the rotation operation can be smoothed. Moreover, since the hydraulic cylinder H coupled to the upright shaft 3 rotates together with the upright shaft 3, the movable oil passages 16, 17 connecting the openings 10, 11 on the peripheral surface of the upright shaft 3 and the hydraulic cylinder H. Is kept stationary with respect to the upright shaft 3 and the hydraulic cylinder H, and the movable oil passages 16 and 17 are not bent or deformed.

Therefore, for example, a steel pipe having a lower expansion coefficient than that of a rubber hose can be applied as the movable oil passages 16 and 17, thereby minimizing pressure loss in the entire hydraulic passage 6. Further, since the pipe can be bent along a thin steel pipe, for example, at a right angle, the pipe space can be reduced. Alternatively, even when a rubber hose is applied as the movable oil passages 16 and 17, the deterioration does not proceed due to frequent deformation of the rubber hose.

Further, there are few places where the hydraulic path 6 is exposed to the outside of the housing 2 of the lifting carriage 1,
Since the hydraulic path 6 does not protrude greatly from the housing 2, there is no possibility that the hydraulic path 6 is caught on a load or the like during the operation of the lifting carriage 1. Moreover, it is advantageous that the hydraulic path 6 hardly enters the field of view of the operator who operates the lift carriage 1 behind the lift carriage 1.

Next, another example of the lifting carriage according to the embodiment of the present invention will be described. In the following, Example 1
The components already described above are denoted by the same reference numerals, and the illustration or detailed description thereof will be omitted. FIG.
In this example, two fixed oil passages 8 and 9 supply hydraulic pressure only to one of the shaft ends 30 and 31 of the upright shaft 3. Here, “one” means one side, and corresponds to either “one shaft end 30” or “the other shaft end 31”.

In this embodiment, the swivel pipe joint is configured as follows. That is, the two fixed oil passages 8 and 9 are connected to the annular casing 33 that separates the gaps 18 and 19 from the peripheral surface of the other shaft end 31.
The hydraulic oil can enter and exit between the two fixed oil passages 8 and 9 and the gaps 18 and 19. Further, two in-shaft oil passages 12 and 13 extending upward in parallel with each other from the other shaft end 31 to the middle in the axial direction are formed, corresponding to the gaps 18 and 19 on the peripheral surface of the other shaft end 31. Openings 22 and 23 communicating with the two in-shaft oil passages 12 and 13 are formed at the positions where they are to be formed.

Since the annular casing 33 has two shaft retaining rings 34 sandwiching the upper and lower portions thereof, respectively, on the peripheral surface of the other shaft end 31, the upright shaft 3 is allowed to rotate, but the upright shaft 3 However, it does not move in the axial direction. The gaps 18 and 19 are separated from each other by an O-ring 35, and the O-ring 3
6 is sealed so that the hydraulic oil does not leak to the outside of the annular casing 33.

According to the above configuration, the hydraulic path can be more freely piped to the lift carriage 1, and the piping work in the manufacturing process can be facilitated. Specifically, the in-shaft oil passages 12 and 13 do not necessarily open to a position that bisects the axial direction of the upright shaft. As illustrated in FIG.
The other shaft end 31 may be offset toward the other shaft end 31. In such a case, the in-shaft oil passages 12, 1
Since the distance for digging 3 from the other shaft end 31 of the upright shaft using a drill or the like is shallower than the distance for digging 3 from the one shaft end 30, manufacturing time and cost can be reduced. Also,
Rather than piping the two fixed oil passages 8 and 9 apart from each other inside the elevating carriage 1, the piping can be done only once by bundling the two fixed oil passages 8 and 9. Fixed oil passage 8,
9 can be passed through a place where the worker can easily work.

“One” or “the other” described above is a relative designation. Therefore, one shaft end 30
An annular casing 33 is attached to each other, and two in-shaft oil passages 12 and 13 extending downward in parallel with each other from one shaft end 30 to the middle in the axial direction are formed. Openings 22 and 23 communicating with the two in-shaft oil passages 12 and 13 may be formed.

It should be noted that the present invention can be implemented in a mode in which various improvements, modifications, or variations are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention. For example, the advance / retreat member 43 does not have to be in the form of a sheath or a bag, and may be in the form of a grooved rail, a plate, or a rod as long as it can support the pallet 6 well.

Further, it is not always necessary to provide two hydraulic paths 6. In this case, the fixed oil passage 9, the in-shaft oil passage 13, the swivel pipe joint 15, and the movable oil conduit 17 are omitted, and the fixed oil passage 8, the in-shaft oil passage 1 are omitted.
2, to move the operating rod 61 of the hydraulic cylinder H forward by the hydraulic pressure supplied from the hydraulic pressure generating unit 6 through the hydraulic path 6 including the swivel joint 14 and the movable oil path 16, a spring or the like The actuating rod 61 may be pushed back upward by the biasing means. The hydraulic oil discharged from the hydraulic cylinder H in this process may be returned to the hydraulic pressure generating unit 7 through the same hydraulic path 6 again.

The elevating carriage according to the present invention can extend the entire length of the fork as desired by advancing the advancing and retracting member. Further, if the rotating operation of the fork is performed with the advance / retreat member retracted, the turning radius of the fork can be reduced. Therefore, the present invention is a technique useful for carrying out cargo handling work in a narrow path between rack shelves or the like facing each other.

The side view which shows the outline of the three-way stacking track to which the raising / lowering carriage based on Example 1 of this invention was applied. The side view of the principal part of the raising / lowering carriage which concerns on Example 1 of this invention. Sectional drawing of the fork applied to the raising / lowering carriage based on Example 1 of this invention. The perspective view of the advance / retreat member applied to the raising / lowering carriage which concerns on Example 1 of this invention. The perspective view which shows the modification of the advance / retreat member applied to the raising / lowering carriage based on Example 1 of this invention. The side view which shows the further modification of the advance / retreat member applied to the raising / lowering carriage which concerns on Example 1 of this invention. The side view of the principal part of the 3 direction stacking track to which the raising / lowering carriage which concerns on Example 1 of this invention was applied. Sectional drawing of the principal part of the raising / lowering carriage which concerns on Example 2 of this invention. The perspective view of the three-way stacking track provided with the raising / lowering carriage of a prior art example.

Explanation of symbols

1: Lifting carriage 3: Upright shaft 4: Fork 6: Hydraulic path 8, 9: Fixed oil path 10, 11: Opening 12, 13: In-shaft oil path 14, 15: Swivel fitting 16, 17: Movable oil path 30 , 31: shaft end 40: rear end 42: front end 43: advance / retreat member 60: feed side port 61: actuating rod 62: return side port H: hydraulic cylinder

Claims (6)

In an elevating carriage having a rotating upright shaft and a fork revolving around the upright shaft, an advancing / retracting member capable of supporting a pallet is attached to the fork so as to freely advance and retract, and the hydraulic cylinder moves the advancing / retreating member forward and backward. A lifting carriage characterized in that hydraulic pressure is supplied through a hydraulic path that passes through an upright shaft. The fork has a rear end connected to the upright shaft and a tip extending horizontally from the upright shaft;
The elevating carriage according to claim 1, wherein the hydraulic cylinder has an operating rod that projects the advance / retreat member from a front end of the fork or retracts toward a rear end of the fork. The elevating carriage according to claim 2, further comprising two each of the forks and the hydraulic cylinders, and the hydraulic cylinders are provided for each of the forks. The hydraulic path includes a fixed oil path that supplies hydraulic pressure to the shaft end of the upright shaft, and an in-shaft oil path that extends from the shaft end of the upright shaft to the middle in the axial direction and has an opening in the circumferential surface in the middle of the axial direction. And a swivel pipe joint that connects the fixed oil passage to the shaft end of the upright shaft, and a movable oil passage that connects one end to the opening of the in-shaft oil passage and connects the other end to the hydraulic cylinder. The raising / lowering carriage of Claim 2 or 3 characterized by the above-mentioned. The hydraulic path includes two paths alternately serving as a feed side or a return side, and one path of the two paths is connected to one of both shaft ends of the upright shaft, and the two paths The other route is
Connected to the other of both shaft ends,
Forming two in-shaft oil passages each extending from the both shaft ends to the middle in the axial direction on the upright shaft, each opening an individual opening on the circumferential surface in the middle in the axial direction;
The hydraulic cylinder has a feed port for introducing hydraulic pressure to advance the operating rod, and a return port for introducing hydraulic pressure to retract the operating rod, and each of the two in-shaft oil passages. The elevating carriage according to claim 4, wherein the opening is connected to each of the feed side port and the return side port through the two movable oil passages. The hydraulic path includes two paths that alternately serve as a feeding side or a returning side, and the two paths are
Connected to one shaft end of the upright shaft,
Forming two in-shaft oil passages each extending from the one shaft end to the middle in the axial direction on the upright shaft, each opening an individual opening on the circumferential surface in the middle of the axial direction;
The hydraulic cylinder has a feed port for introducing hydraulic pressure to advance the operating rod, and a return port for introducing hydraulic pressure to retract the operating rod, and each of the two in-shaft oil passages. The elevating carriage according to claim 4, wherein the opening is connected to each of the feed side port and the return side port through the two movable oil passages.

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